| /* |
| * Infrastructure for profiling code inserted by 'gcc -pg'. |
| * |
| * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> |
| * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> |
| * |
| * Originally ported from the -rt patch by: |
| * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> |
| * |
| * Based on code in the latency_tracer, that is: |
| * |
| * Copyright (C) 2004-2006 Ingo Molnar |
| * Copyright (C) 2004 Nadia Yvette Chambers |
| */ |
| |
| #include <linux/stop_machine.h> |
| #include <linux/clocksource.h> |
| #include <linux/sched/task.h> |
| #include <linux/kallsyms.h> |
| #include <linux/seq_file.h> |
| #include <linux/suspend.h> |
| #include <linux/tracefs.h> |
| #include <linux/hardirq.h> |
| #include <linux/kthread.h> |
| #include <linux/uaccess.h> |
| #include <linux/bsearch.h> |
| #include <linux/module.h> |
| #include <linux/ftrace.h> |
| #include <linux/sysctl.h> |
| #include <linux/slab.h> |
| #include <linux/ctype.h> |
| #include <linux/sort.h> |
| #include <linux/list.h> |
| #include <linux/hash.h> |
| #include <linux/rcupdate.h> |
| |
| #include <trace/events/sched.h> |
| |
| #include <asm/sections.h> |
| #include <asm/setup.h> |
| |
| #include "trace_output.h" |
| #include "trace_stat.h" |
| |
| #define FTRACE_WARN_ON(cond) \ |
| ({ \ |
| int ___r = cond; \ |
| if (WARN_ON(___r)) \ |
| ftrace_kill(); \ |
| ___r; \ |
| }) |
| |
| #define FTRACE_WARN_ON_ONCE(cond) \ |
| ({ \ |
| int ___r = cond; \ |
| if (WARN_ON_ONCE(___r)) \ |
| ftrace_kill(); \ |
| ___r; \ |
| }) |
| |
| /* hash bits for specific function selection */ |
| #define FTRACE_HASH_BITS 7 |
| #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) |
| #define FTRACE_HASH_DEFAULT_BITS 10 |
| #define FTRACE_HASH_MAX_BITS 12 |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE |
| #define INIT_OPS_HASH(opsname) \ |
| .func_hash = &opsname.local_hash, \ |
| .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), |
| #define ASSIGN_OPS_HASH(opsname, val) \ |
| .func_hash = val, \ |
| .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), |
| #else |
| #define INIT_OPS_HASH(opsname) |
| #define ASSIGN_OPS_HASH(opsname, val) |
| #endif |
| |
| static struct ftrace_ops ftrace_list_end __read_mostly = { |
| .func = ftrace_stub, |
| .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB, |
| INIT_OPS_HASH(ftrace_list_end) |
| }; |
| |
| /* ftrace_enabled is a method to turn ftrace on or off */ |
| int ftrace_enabled __read_mostly; |
| static int last_ftrace_enabled; |
| |
| /* Current function tracing op */ |
| struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; |
| /* What to set function_trace_op to */ |
| static struct ftrace_ops *set_function_trace_op; |
| |
| static bool ftrace_pids_enabled(struct ftrace_ops *ops) |
| { |
| struct trace_array *tr; |
| |
| if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private) |
| return false; |
| |
| tr = ops->private; |
| |
| return tr->function_pids != NULL; |
| } |
| |
| static void ftrace_update_trampoline(struct ftrace_ops *ops); |
| |
| /* |
| * ftrace_disabled is set when an anomaly is discovered. |
| * ftrace_disabled is much stronger than ftrace_enabled. |
| */ |
| static int ftrace_disabled __read_mostly; |
| |
| static DEFINE_MUTEX(ftrace_lock); |
| |
| static struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end; |
| ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
| static struct ftrace_ops global_ops; |
| |
| #if ARCH_SUPPORTS_FTRACE_OPS |
| static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
| struct ftrace_ops *op, struct pt_regs *regs); |
| #else |
| /* See comment below, where ftrace_ops_list_func is defined */ |
| static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); |
| #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) |
| #endif |
| |
| /* |
| * Traverse the ftrace_global_list, invoking all entries. The reason that we |
| * can use rcu_dereference_raw_notrace() is that elements removed from this list |
| * are simply leaked, so there is no need to interact with a grace-period |
| * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle |
| * concurrent insertions into the ftrace_global_list. |
| * |
| * Silly Alpha and silly pointer-speculation compiler optimizations! |
| */ |
| #define do_for_each_ftrace_op(op, list) \ |
| op = rcu_dereference_raw_notrace(list); \ |
| do |
| |
| /* |
| * Optimized for just a single item in the list (as that is the normal case). |
| */ |
| #define while_for_each_ftrace_op(op) \ |
| while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ |
| unlikely((op) != &ftrace_list_end)) |
| |
| static inline void ftrace_ops_init(struct ftrace_ops *ops) |
| { |
| #ifdef CONFIG_DYNAMIC_FTRACE |
| if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { |
| mutex_init(&ops->local_hash.regex_lock); |
| ops->func_hash = &ops->local_hash; |
| ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
| } |
| #endif |
| } |
| |
| /** |
| * ftrace_nr_registered_ops - return number of ops registered |
| * |
| * Returns the number of ftrace_ops registered and tracing functions |
| */ |
| int ftrace_nr_registered_ops(void) |
| { |
| struct ftrace_ops *ops; |
| int cnt = 0; |
| |
| mutex_lock(&ftrace_lock); |
| |
| for (ops = rcu_dereference_protected(ftrace_ops_list, |
| lockdep_is_held(&ftrace_lock)); |
| ops != &ftrace_list_end; |
| ops = rcu_dereference_protected(ops->next, |
| lockdep_is_held(&ftrace_lock))) |
| cnt++; |
| |
| mutex_unlock(&ftrace_lock); |
| |
| return cnt; |
| } |
| |
| static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
| struct ftrace_ops *op, struct pt_regs *regs) |
| { |
| struct trace_array *tr = op->private; |
| |
| if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid)) |
| return; |
| |
| op->saved_func(ip, parent_ip, op, regs); |
| } |
| |
| /** |
| * clear_ftrace_function - reset the ftrace function |
| * |
| * This NULLs the ftrace function and in essence stops |
| * tracing. There may be lag |
| */ |
| void clear_ftrace_function(void) |
| { |
| ftrace_trace_function = ftrace_stub; |
| } |
| |
| static void ftrace_sync(struct work_struct *work) |
| { |
| /* |
| * This function is just a stub to implement a hard force |
| * of synchronize_sched(). This requires synchronizing |
| * tasks even in userspace and idle. |
| * |
| * Yes, function tracing is rude. |
| */ |
| } |
| |
| static void ftrace_sync_ipi(void *data) |
| { |
| /* Probably not needed, but do it anyway */ |
| smp_rmb(); |
| } |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| static void update_function_graph_func(void); |
| |
| /* Both enabled by default (can be cleared by function_graph tracer flags */ |
| static bool fgraph_sleep_time = true; |
| static bool fgraph_graph_time = true; |
| |
| #else |
| static inline void update_function_graph_func(void) { } |
| #endif |
| |
| |
| static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) |
| { |
| /* |
| * If this is a dynamic, RCU, or per CPU ops, or we force list func, |
| * then it needs to call the list anyway. |
| */ |
| if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) || |
| FTRACE_FORCE_LIST_FUNC) |
| return ftrace_ops_list_func; |
| |
| return ftrace_ops_get_func(ops); |
| } |
| |
| static void update_ftrace_function(void) |
| { |
| ftrace_func_t func; |
| |
| /* |
| * Prepare the ftrace_ops that the arch callback will use. |
| * If there's only one ftrace_ops registered, the ftrace_ops_list |
| * will point to the ops we want. |
| */ |
| set_function_trace_op = rcu_dereference_protected(ftrace_ops_list, |
| lockdep_is_held(&ftrace_lock)); |
| |
| /* If there's no ftrace_ops registered, just call the stub function */ |
| if (set_function_trace_op == &ftrace_list_end) { |
| func = ftrace_stub; |
| |
| /* |
| * If we are at the end of the list and this ops is |
| * recursion safe and not dynamic and the arch supports passing ops, |
| * then have the mcount trampoline call the function directly. |
| */ |
| } else if (rcu_dereference_protected(ftrace_ops_list->next, |
| lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { |
| func = ftrace_ops_get_list_func(ftrace_ops_list); |
| |
| } else { |
| /* Just use the default ftrace_ops */ |
| set_function_trace_op = &ftrace_list_end; |
| func = ftrace_ops_list_func; |
| } |
| |
| update_function_graph_func(); |
| |
| /* If there's no change, then do nothing more here */ |
| if (ftrace_trace_function == func) |
| return; |
| |
| /* |
| * If we are using the list function, it doesn't care |
| * about the function_trace_ops. |
| */ |
| if (func == ftrace_ops_list_func) { |
| ftrace_trace_function = func; |
| /* |
| * Don't even bother setting function_trace_ops, |
| * it would be racy to do so anyway. |
| */ |
| return; |
| } |
| |
| #ifndef CONFIG_DYNAMIC_FTRACE |
| /* |
| * For static tracing, we need to be a bit more careful. |
| * The function change takes affect immediately. Thus, |
| * we need to coorditate the setting of the function_trace_ops |
| * with the setting of the ftrace_trace_function. |
| * |
| * Set the function to the list ops, which will call the |
| * function we want, albeit indirectly, but it handles the |
| * ftrace_ops and doesn't depend on function_trace_op. |
| */ |
| ftrace_trace_function = ftrace_ops_list_func; |
| /* |
| * Make sure all CPUs see this. Yes this is slow, but static |
| * tracing is slow and nasty to have enabled. |
| */ |
| schedule_on_each_cpu(ftrace_sync); |
| /* Now all cpus are using the list ops. */ |
| function_trace_op = set_function_trace_op; |
| /* Make sure the function_trace_op is visible on all CPUs */ |
| smp_wmb(); |
| /* Nasty way to force a rmb on all cpus */ |
| smp_call_function(ftrace_sync_ipi, NULL, 1); |
| /* OK, we are all set to update the ftrace_trace_function now! */ |
| #endif /* !CONFIG_DYNAMIC_FTRACE */ |
| |
| ftrace_trace_function = func; |
| } |
| |
| int using_ftrace_ops_list_func(void) |
| { |
| return ftrace_trace_function == ftrace_ops_list_func; |
| } |
| |
| static void add_ftrace_ops(struct ftrace_ops __rcu **list, |
| struct ftrace_ops *ops) |
| { |
| rcu_assign_pointer(ops->next, *list); |
| |
| /* |
| * We are entering ops into the list but another |
| * CPU might be walking that list. We need to make sure |
| * the ops->next pointer is valid before another CPU sees |
| * the ops pointer included into the list. |
| */ |
| rcu_assign_pointer(*list, ops); |
| } |
| |
| static int remove_ftrace_ops(struct ftrace_ops __rcu **list, |
| struct ftrace_ops *ops) |
| { |
| struct ftrace_ops **p; |
| |
| /* |
| * If we are removing the last function, then simply point |
| * to the ftrace_stub. |
| */ |
| if (rcu_dereference_protected(*list, |
| lockdep_is_held(&ftrace_lock)) == ops && |
| rcu_dereference_protected(ops->next, |
| lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { |
| *list = &ftrace_list_end; |
| return 0; |
| } |
| |
| for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
| if (*p == ops) |
| break; |
| |
| if (*p != ops) |
| return -1; |
| |
| *p = (*p)->next; |
| return 0; |
| } |
| |
| static void ftrace_update_trampoline(struct ftrace_ops *ops); |
| |
| static int __register_ftrace_function(struct ftrace_ops *ops) |
| { |
| if (ops->flags & FTRACE_OPS_FL_DELETED) |
| return -EINVAL; |
| |
| if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
| return -EBUSY; |
| |
| #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
| /* |
| * If the ftrace_ops specifies SAVE_REGS, then it only can be used |
| * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. |
| * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. |
| */ |
| if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && |
| !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) |
| return -EINVAL; |
| |
| if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) |
| ops->flags |= FTRACE_OPS_FL_SAVE_REGS; |
| #endif |
| |
| if (!core_kernel_data((unsigned long)ops)) |
| ops->flags |= FTRACE_OPS_FL_DYNAMIC; |
| |
| add_ftrace_ops(&ftrace_ops_list, ops); |
| |
| /* Always save the function, and reset at unregistering */ |
| ops->saved_func = ops->func; |
| |
| if (ftrace_pids_enabled(ops)) |
| ops->func = ftrace_pid_func; |
| |
| ftrace_update_trampoline(ops); |
| |
| if (ftrace_enabled) |
| update_ftrace_function(); |
| |
| return 0; |
| } |
| |
| static int __unregister_ftrace_function(struct ftrace_ops *ops) |
| { |
| int ret; |
| |
| if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
| return -EBUSY; |
| |
| ret = remove_ftrace_ops(&ftrace_ops_list, ops); |
| |
| if (ret < 0) |
| return ret; |
| |
| if (ftrace_enabled) |
| update_ftrace_function(); |
| |
| ops->func = ops->saved_func; |
| |
| return 0; |
| } |
| |
| static void ftrace_update_pid_func(void) |
| { |
| struct ftrace_ops *op; |
| |
| /* Only do something if we are tracing something */ |
| if (ftrace_trace_function == ftrace_stub) |
| return; |
| |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| if (op->flags & FTRACE_OPS_FL_PID) { |
| op->func = ftrace_pids_enabled(op) ? |
| ftrace_pid_func : op->saved_func; |
| ftrace_update_trampoline(op); |
| } |
| } while_for_each_ftrace_op(op); |
| |
| update_ftrace_function(); |
| } |
| |
| #ifdef CONFIG_FUNCTION_PROFILER |
| struct ftrace_profile { |
| struct hlist_node node; |
| unsigned long ip; |
| unsigned long counter; |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| unsigned long long time; |
| unsigned long long time_squared; |
| #endif |
| }; |
| |
| struct ftrace_profile_page { |
| struct ftrace_profile_page *next; |
| unsigned long index; |
| struct ftrace_profile records[]; |
| }; |
| |
| struct ftrace_profile_stat { |
| atomic_t disabled; |
| struct hlist_head *hash; |
| struct ftrace_profile_page *pages; |
| struct ftrace_profile_page *start; |
| struct tracer_stat stat; |
| }; |
| |
| #define PROFILE_RECORDS_SIZE \ |
| (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) |
| |
| #define PROFILES_PER_PAGE \ |
| (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) |
| |
| static int ftrace_profile_enabled __read_mostly; |
| |
| /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ |
| static DEFINE_MUTEX(ftrace_profile_lock); |
| |
| static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
| |
| #define FTRACE_PROFILE_HASH_BITS 10 |
| #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) |
| |
| static void * |
| function_stat_next(void *v, int idx) |
| { |
| struct ftrace_profile *rec = v; |
| struct ftrace_profile_page *pg; |
| |
| pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
| |
| again: |
| if (idx != 0) |
| rec++; |
| |
| if ((void *)rec >= (void *)&pg->records[pg->index]) { |
| pg = pg->next; |
| if (!pg) |
| return NULL; |
| rec = &pg->records[0]; |
| if (!rec->counter) |
| goto again; |
| } |
| |
| return rec; |
| } |
| |
| static void *function_stat_start(struct tracer_stat *trace) |
| { |
| struct ftrace_profile_stat *stat = |
| container_of(trace, struct ftrace_profile_stat, stat); |
| |
| if (!stat || !stat->start) |
| return NULL; |
| |
| return function_stat_next(&stat->start->records[0], 0); |
| } |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| /* function graph compares on total time */ |
| static int function_stat_cmp(void *p1, void *p2) |
| { |
| struct ftrace_profile *a = p1; |
| struct ftrace_profile *b = p2; |
| |
| if (a->time < b->time) |
| return -1; |
| if (a->time > b->time) |
| return 1; |
| else |
| return 0; |
| } |
| #else |
| /* not function graph compares against hits */ |
| static int function_stat_cmp(void *p1, void *p2) |
| { |
| struct ftrace_profile *a = p1; |
| struct ftrace_profile *b = p2; |
| |
| if (a->counter < b->counter) |
| return -1; |
| if (a->counter > b->counter) |
| return 1; |
| else |
| return 0; |
| } |
| #endif |
| |
| static int function_stat_headers(struct seq_file *m) |
| { |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| seq_puts(m, " Function " |
| "Hit Time Avg s^2\n" |
| " -------- " |
| "--- ---- --- ---\n"); |
| #else |
| seq_puts(m, " Function Hit\n" |
| " -------- ---\n"); |
| #endif |
| return 0; |
| } |
| |
| static int function_stat_show(struct seq_file *m, void *v) |
| { |
| struct ftrace_profile *rec = v; |
| char str[KSYM_SYMBOL_LEN]; |
| int ret = 0; |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| static struct trace_seq s; |
| unsigned long long avg; |
| unsigned long long stddev; |
| #endif |
| mutex_lock(&ftrace_profile_lock); |
| |
| /* we raced with function_profile_reset() */ |
| if (unlikely(rec->counter == 0)) { |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| avg = rec->time; |
| do_div(avg, rec->counter); |
| if (tracing_thresh && (avg < tracing_thresh)) |
| goto out; |
| #endif |
| |
| kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| seq_puts(m, " "); |
| |
| /* Sample standard deviation (s^2) */ |
| if (rec->counter <= 1) |
| stddev = 0; |
| else { |
| /* |
| * Apply Welford's method: |
| * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) |
| */ |
| stddev = rec->counter * rec->time_squared - |
| rec->time * rec->time; |
| |
| /* |
| * Divide only 1000 for ns^2 -> us^2 conversion. |
| * trace_print_graph_duration will divide 1000 again. |
| */ |
| do_div(stddev, rec->counter * (rec->counter - 1) * 1000); |
| } |
| |
| trace_seq_init(&s); |
| trace_print_graph_duration(rec->time, &s); |
| trace_seq_puts(&s, " "); |
| trace_print_graph_duration(avg, &s); |
| trace_seq_puts(&s, " "); |
| trace_print_graph_duration(stddev, &s); |
| trace_print_seq(m, &s); |
| #endif |
| seq_putc(m, '\n'); |
| out: |
| mutex_unlock(&ftrace_profile_lock); |
| |
| return ret; |
| } |
| |
| static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
| { |
| struct ftrace_profile_page *pg; |
| |
| pg = stat->pages = stat->start; |
| |
| while (pg) { |
| memset(pg->records, 0, PROFILE_RECORDS_SIZE); |
| pg->index = 0; |
| pg = pg->next; |
| } |
| |
| memset(stat->hash, 0, |
| FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
| } |
| |
| int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
| { |
| struct ftrace_profile_page *pg; |
| int functions; |
| int pages; |
| int i; |
| |
| /* If we already allocated, do nothing */ |
| if (stat->pages) |
| return 0; |
| |
| stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
| if (!stat->pages) |
| return -ENOMEM; |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE |
| functions = ftrace_update_tot_cnt; |
| #else |
| /* |
| * We do not know the number of functions that exist because |
| * dynamic tracing is what counts them. With past experience |
| * we have around 20K functions. That should be more than enough. |
| * It is highly unlikely we will execute every function in |
| * the kernel. |
| */ |
| functions = 20000; |
| #endif |
| |
| pg = stat->start = stat->pages; |
| |
| pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
| |
| for (i = 1; i < pages; i++) { |
| pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
| if (!pg->next) |
| goto out_free; |
| pg = pg->next; |
| } |
| |
| return 0; |
| |
| out_free: |
| pg = stat->start; |
| while (pg) { |
| unsigned long tmp = (unsigned long)pg; |
| |
| pg = pg->next; |
| free_page(tmp); |
| } |
| |
| stat->pages = NULL; |
| stat->start = NULL; |
| |
| return -ENOMEM; |
| } |
| |
| static int ftrace_profile_init_cpu(int cpu) |
| { |
| struct ftrace_profile_stat *stat; |
| int size; |
| |
| stat = &per_cpu(ftrace_profile_stats, cpu); |
| |
| if (stat->hash) { |
| /* If the profile is already created, simply reset it */ |
| ftrace_profile_reset(stat); |
| return 0; |
| } |
| |
| /* |
| * We are profiling all functions, but usually only a few thousand |
| * functions are hit. We'll make a hash of 1024 items. |
| */ |
| size = FTRACE_PROFILE_HASH_SIZE; |
| |
| stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
| |
| if (!stat->hash) |
| return -ENOMEM; |
| |
| /* Preallocate the function profiling pages */ |
| if (ftrace_profile_pages_init(stat) < 0) { |
| kfree(stat->hash); |
| stat->hash = NULL; |
| return -ENOMEM; |
| } |
| |
| return 0; |
| } |
| |
| static int ftrace_profile_init(void) |
| { |
| int cpu; |
| int ret = 0; |
| |
| for_each_possible_cpu(cpu) { |
| ret = ftrace_profile_init_cpu(cpu); |
| if (ret) |
| break; |
| } |
| |
| return ret; |
| } |
| |
| /* interrupts must be disabled */ |
| static struct ftrace_profile * |
| ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) |
| { |
| struct ftrace_profile *rec; |
| struct hlist_head *hhd; |
| unsigned long key; |
| |
| key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
| hhd = &stat->hash[key]; |
| |
| if (hlist_empty(hhd)) |
| return NULL; |
| |
| hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
| if (rec->ip == ip) |
| return rec; |
| } |
| |
| return NULL; |
| } |
| |
| static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
| struct ftrace_profile *rec) |
| { |
| unsigned long key; |
| |
| key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
| hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
| } |
| |
| /* |
| * The memory is already allocated, this simply finds a new record to use. |
| */ |
| static struct ftrace_profile * |
| ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
| { |
| struct ftrace_profile *rec = NULL; |
| |
| /* prevent recursion (from NMIs) */ |
| if (atomic_inc_return(&stat->disabled) != 1) |
| goto out; |
| |
| /* |
| * Try to find the function again since an NMI |
| * could have added it |
| */ |
| rec = ftrace_find_profiled_func(stat, ip); |
| if (rec) |
| goto out; |
| |
| if (stat->pages->index == PROFILES_PER_PAGE) { |
| if (!stat->pages->next) |
| goto out; |
| stat->pages = stat->pages->next; |
| } |
| |
| rec = &stat->pages->records[stat->pages->index++]; |
| rec->ip = ip; |
| ftrace_add_profile(stat, rec); |
| |
| out: |
| atomic_dec(&stat->disabled); |
| |
| return rec; |
| } |
| |
| static void |
| function_profile_call(unsigned long ip, unsigned long parent_ip, |
| struct ftrace_ops *ops, struct pt_regs *regs) |
| { |
| struct ftrace_profile_stat *stat; |
| struct ftrace_profile *rec; |
| unsigned long flags; |
| |
| if (!ftrace_profile_enabled) |
| return; |
| |
| local_irq_save(flags); |
| |
| stat = this_cpu_ptr(&ftrace_profile_stats); |
| if (!stat->hash || !ftrace_profile_enabled) |
| goto out; |
| |
| rec = ftrace_find_profiled_func(stat, ip); |
| if (!rec) { |
| rec = ftrace_profile_alloc(stat, ip); |
| if (!rec) |
| goto out; |
| } |
| |
| rec->counter++; |
| out: |
| local_irq_restore(flags); |
| } |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| static int profile_graph_entry(struct ftrace_graph_ent *trace) |
| { |
| int index = trace->depth; |
| |
| function_profile_call(trace->func, 0, NULL, NULL); |
| |
| /* If function graph is shutting down, ret_stack can be NULL */ |
| if (!current->ret_stack) |
| return 0; |
| |
| if (index >= 0 && index < FTRACE_RETFUNC_DEPTH) |
| current->ret_stack[index].subtime = 0; |
| |
| return 1; |
| } |
| |
| static void profile_graph_return(struct ftrace_graph_ret *trace) |
| { |
| struct ftrace_profile_stat *stat; |
| unsigned long long calltime; |
| struct ftrace_profile *rec; |
| unsigned long flags; |
| |
| local_irq_save(flags); |
| stat = this_cpu_ptr(&ftrace_profile_stats); |
| if (!stat->hash || !ftrace_profile_enabled) |
| goto out; |
| |
| /* If the calltime was zero'd ignore it */ |
| if (!trace->calltime) |
| goto out; |
| |
| calltime = trace->rettime - trace->calltime; |
| |
| if (!fgraph_graph_time) { |
| int index; |
| |
| index = trace->depth; |
| |
| /* Append this call time to the parent time to subtract */ |
| if (index) |
| current->ret_stack[index - 1].subtime += calltime; |
| |
| if (current->ret_stack[index].subtime < calltime) |
| calltime -= current->ret_stack[index].subtime; |
| else |
| calltime = 0; |
| } |
| |
| rec = ftrace_find_profiled_func(stat, trace->func); |
| if (rec) { |
| rec->time += calltime; |
| rec->time_squared += calltime * calltime; |
| } |
| |
| out: |
| local_irq_restore(flags); |
| } |
| |
| static int register_ftrace_profiler(void) |
| { |
| return register_ftrace_graph(&profile_graph_return, |
| &profile_graph_entry); |
| } |
| |
| static void unregister_ftrace_profiler(void) |
| { |
| unregister_ftrace_graph(); |
| } |
| #else |
| static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
| .func = function_profile_call, |
| .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
| INIT_OPS_HASH(ftrace_profile_ops) |
| }; |
| |
| static int register_ftrace_profiler(void) |
| { |
| return register_ftrace_function(&ftrace_profile_ops); |
| } |
| |
| static void unregister_ftrace_profiler(void) |
| { |
| unregister_ftrace_function(&ftrace_profile_ops); |
| } |
| #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
| |
| static ssize_t |
| ftrace_profile_write(struct file *filp, const char __user *ubuf, |
| size_t cnt, loff_t *ppos) |
| { |
| unsigned long val; |
| int ret; |
| |
| ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
| if (ret) |
| return ret; |
| |
| val = !!val; |
| |
| mutex_lock(&ftrace_profile_lock); |
| if (ftrace_profile_enabled ^ val) { |
| if (val) { |
| ret = ftrace_profile_init(); |
| if (ret < 0) { |
| cnt = ret; |
| goto out; |
| } |
| |
| ret = register_ftrace_profiler(); |
| if (ret < 0) { |
| cnt = ret; |
| goto out; |
| } |
| ftrace_profile_enabled = 1; |
| } else { |
| ftrace_profile_enabled = 0; |
| /* |
| * unregister_ftrace_profiler calls stop_machine |
| * so this acts like an synchronize_sched. |
| */ |
| unregister_ftrace_profiler(); |
| } |
| } |
| out: |
| mutex_unlock(&ftrace_profile_lock); |
| |
| *ppos += cnt; |
| |
| return cnt; |
| } |
| |
| static ssize_t |
| ftrace_profile_read(struct file *filp, char __user *ubuf, |
| size_t cnt, loff_t *ppos) |
| { |
| char buf[64]; /* big enough to hold a number */ |
| int r; |
| |
| r = sprintf(buf, "%u\n", ftrace_profile_enabled); |
| return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
| } |
| |
| static const struct file_operations ftrace_profile_fops = { |
| .open = tracing_open_generic, |
| .read = ftrace_profile_read, |
| .write = ftrace_profile_write, |
| .llseek = default_llseek, |
| }; |
| |
| /* used to initialize the real stat files */ |
| static struct tracer_stat function_stats __initdata = { |
| .name = "functions", |
| .stat_start = function_stat_start, |
| .stat_next = function_stat_next, |
| .stat_cmp = function_stat_cmp, |
| .stat_headers = function_stat_headers, |
| .stat_show = function_stat_show |
| }; |
| |
| static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
| { |
| struct ftrace_profile_stat *stat; |
| struct dentry *entry; |
| char *name; |
| int ret; |
| int cpu; |
| |
| for_each_possible_cpu(cpu) { |
| stat = &per_cpu(ftrace_profile_stats, cpu); |
| |
| name = kasprintf(GFP_KERNEL, "function%d", cpu); |
| if (!name) { |
| /* |
| * The files created are permanent, if something happens |
| * we still do not free memory. |
| */ |
| WARN(1, |
| "Could not allocate stat file for cpu %d\n", |
| cpu); |
| return; |
| } |
| stat->stat = function_stats; |
| stat->stat.name = name; |
| ret = register_stat_tracer(&stat->stat); |
| if (ret) { |
| WARN(1, |
| "Could not register function stat for cpu %d\n", |
| cpu); |
| kfree(name); |
| return; |
| } |
| } |
| |
| entry = tracefs_create_file("function_profile_enabled", 0644, |
| d_tracer, NULL, &ftrace_profile_fops); |
| if (!entry) |
| pr_warn("Could not create tracefs 'function_profile_enabled' entry\n"); |
| } |
| |
| #else /* CONFIG_FUNCTION_PROFILER */ |
| static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
| { |
| } |
| #endif /* CONFIG_FUNCTION_PROFILER */ |
| |
| static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| static int ftrace_graph_active; |
| #else |
| # define ftrace_graph_active 0 |
| #endif |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE |
| |
| static struct ftrace_ops *removed_ops; |
| |
| /* |
| * Set when doing a global update, like enabling all recs or disabling them. |
| * It is not set when just updating a single ftrace_ops. |
| */ |
| static bool update_all_ops; |
| |
| #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
| # error Dynamic ftrace depends on MCOUNT_RECORD |
| #endif |
| |
| struct ftrace_func_entry { |
| struct hlist_node hlist; |
| unsigned long ip; |
| }; |
| |
| struct ftrace_func_probe { |
| struct ftrace_probe_ops *probe_ops; |
| struct ftrace_ops ops; |
| struct trace_array *tr; |
| struct list_head list; |
| void *data; |
| int ref; |
| }; |
| |
| /* |
| * We make these constant because no one should touch them, |
| * but they are used as the default "empty hash", to avoid allocating |
| * it all the time. These are in a read only section such that if |
| * anyone does try to modify it, it will cause an exception. |
| */ |
| static const struct hlist_head empty_buckets[1]; |
| static const struct ftrace_hash empty_hash = { |
| .buckets = (struct hlist_head *)empty_buckets, |
| }; |
| #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
| |
| static struct ftrace_ops global_ops = { |
| .func = ftrace_stub, |
| .local_hash.notrace_hash = EMPTY_HASH, |
| .local_hash.filter_hash = EMPTY_HASH, |
| INIT_OPS_HASH(global_ops) |
| .flags = FTRACE_OPS_FL_RECURSION_SAFE | |
| FTRACE_OPS_FL_INITIALIZED | |
| FTRACE_OPS_FL_PID, |
| }; |
| |
| /* |
| * Used by the stack undwinder to know about dynamic ftrace trampolines. |
| */ |
| struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr) |
| { |
| struct ftrace_ops *op = NULL; |
| |
| /* |
| * Some of the ops may be dynamically allocated, |
| * they are freed after a synchronize_sched(). |
| */ |
| preempt_disable_notrace(); |
| |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| /* |
| * This is to check for dynamically allocated trampolines. |
| * Trampolines that are in kernel text will have |
| * core_kernel_text() return true. |
| */ |
| if (op->trampoline && op->trampoline_size) |
| if (addr >= op->trampoline && |
| addr < op->trampoline + op->trampoline_size) { |
| preempt_enable_notrace(); |
| return op; |
| } |
| } while_for_each_ftrace_op(op); |
| preempt_enable_notrace(); |
| |
| return NULL; |
| } |
| |
| /* |
| * This is used by __kernel_text_address() to return true if the |
| * address is on a dynamically allocated trampoline that would |
| * not return true for either core_kernel_text() or |
| * is_module_text_address(). |
| */ |
| bool is_ftrace_trampoline(unsigned long addr) |
| { |
| return ftrace_ops_trampoline(addr) != NULL; |
| } |
| |
| struct ftrace_page { |
| struct ftrace_page *next; |
| struct dyn_ftrace *records; |
| int index; |
| int size; |
| }; |
| |
| #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
| #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) |
| |
| /* estimate from running different kernels */ |
| #define NR_TO_INIT 10000 |
| |
| static struct ftrace_page *ftrace_pages_start; |
| static struct ftrace_page *ftrace_pages; |
| |
| static __always_inline unsigned long |
| ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip) |
| { |
| if (hash->size_bits > 0) |
| return hash_long(ip, hash->size_bits); |
| |
| return 0; |
| } |
| |
| /* Only use this function if ftrace_hash_empty() has already been tested */ |
| static __always_inline struct ftrace_func_entry * |
| __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) |
| { |
| unsigned long key; |
| struct ftrace_func_entry *entry; |
| struct hlist_head *hhd; |
| |
| key = ftrace_hash_key(hash, ip); |
| hhd = &hash->buckets[key]; |
| |
| hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
| if (entry->ip == ip) |
| return entry; |
| } |
| return NULL; |
| } |
| |
| /** |
| * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash |
| * @hash: The hash to look at |
| * @ip: The instruction pointer to test |
| * |
| * Search a given @hash to see if a given instruction pointer (@ip) |
| * exists in it. |
| * |
| * Returns the entry that holds the @ip if found. NULL otherwise. |
| */ |
| struct ftrace_func_entry * |
| ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) |
| { |
| if (ftrace_hash_empty(hash)) |
| return NULL; |
| |
| return __ftrace_lookup_ip(hash, ip); |
| } |
| |
| static void __add_hash_entry(struct ftrace_hash *hash, |
| struct ftrace_func_entry *entry) |
| { |
| struct hlist_head *hhd; |
| unsigned long key; |
| |
| key = ftrace_hash_key(hash, entry->ip); |
| hhd = &hash->buckets[key]; |
| hlist_add_head(&entry->hlist, hhd); |
| hash->count++; |
| } |
| |
| static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) |
| { |
| struct ftrace_func_entry *entry; |
| |
| entry = kmalloc(sizeof(*entry), GFP_KERNEL); |
| if (!entry) |
| return -ENOMEM; |
| |
| entry->ip = ip; |
| __add_hash_entry(hash, entry); |
| |
| return 0; |
| } |
| |
| static void |
| free_hash_entry(struct ftrace_hash *hash, |
| struct ftrace_func_entry *entry) |
| { |
| hlist_del(&entry->hlist); |
| kfree(entry); |
| hash->count--; |
| } |
| |
| static void |
| remove_hash_entry(struct ftrace_hash *hash, |
| struct ftrace_func_entry *entry) |
| { |
| hlist_del_rcu(&entry->hlist); |
| hash->count--; |
| } |
| |
| static void ftrace_hash_clear(struct ftrace_hash *hash) |
| { |
| struct hlist_head *hhd; |
| struct hlist_node *tn; |
| struct ftrace_func_entry *entry; |
| int size = 1 << hash->size_bits; |
| int i; |
| |
| if (!hash->count) |
| return; |
| |
| for (i = 0; i < size; i++) { |
| hhd = &hash->buckets[i]; |
| hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
| free_hash_entry(hash, entry); |
| } |
| FTRACE_WARN_ON(hash->count); |
| } |
| |
| static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod) |
| { |
| list_del(&ftrace_mod->list); |
| kfree(ftrace_mod->module); |
| kfree(ftrace_mod->func); |
| kfree(ftrace_mod); |
| } |
| |
| static void clear_ftrace_mod_list(struct list_head *head) |
| { |
| struct ftrace_mod_load *p, *n; |
| |
| /* stack tracer isn't supported yet */ |
| if (!head) |
| return; |
| |
| mutex_lock(&ftrace_lock); |
| list_for_each_entry_safe(p, n, head, list) |
| free_ftrace_mod(p); |
| mutex_unlock(&ftrace_lock); |
| } |
| |
| static void free_ftrace_hash(struct ftrace_hash *hash) |
| { |
| if (!hash || hash == EMPTY_HASH) |
| return; |
| ftrace_hash_clear(hash); |
| kfree(hash->buckets); |
| kfree(hash); |
| } |
| |
| static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
| { |
| struct ftrace_hash *hash; |
| |
| hash = container_of(rcu, struct ftrace_hash, rcu); |
| free_ftrace_hash(hash); |
| } |
| |
| static void free_ftrace_hash_rcu(struct ftrace_hash *hash) |
| { |
| if (!hash || hash == EMPTY_HASH) |
| return; |
| call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); |
| } |
| |
| void ftrace_free_filter(struct ftrace_ops *ops) |
| { |
| ftrace_ops_init(ops); |
| free_ftrace_hash(ops->func_hash->filter_hash); |
| free_ftrace_hash(ops->func_hash->notrace_hash); |
| } |
| |
| static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
| { |
| struct ftrace_hash *hash; |
| int size; |
| |
| hash = kzalloc(sizeof(*hash), GFP_KERNEL); |
| if (!hash) |
| return NULL; |
| |
| size = 1 << size_bits; |
| hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
| |
| if (!hash->buckets) { |
| kfree(hash); |
| return NULL; |
| } |
| |
| hash->size_bits = size_bits; |
| |
| return hash; |
| } |
| |
| |
| static int ftrace_add_mod(struct trace_array *tr, |
| const char *func, const char *module, |
| int enable) |
| { |
| struct ftrace_mod_load *ftrace_mod; |
| struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace; |
| |
| ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL); |
| if (!ftrace_mod) |
| return -ENOMEM; |
| |
| ftrace_mod->func = kstrdup(func, GFP_KERNEL); |
| ftrace_mod->module = kstrdup(module, GFP_KERNEL); |
| ftrace_mod->enable = enable; |
| |
| if (!ftrace_mod->func || !ftrace_mod->module) |
| goto out_free; |
| |
| list_add(&ftrace_mod->list, mod_head); |
| |
| return 0; |
| |
| out_free: |
| free_ftrace_mod(ftrace_mod); |
| |
| return -ENOMEM; |
| } |
| |
| static struct ftrace_hash * |
| alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) |
| { |
| struct ftrace_func_entry *entry; |
| struct ftrace_hash *new_hash; |
| int size; |
| int ret; |
| int i; |
| |
| new_hash = alloc_ftrace_hash(size_bits); |
| if (!new_hash) |
| return NULL; |
| |
| if (hash) |
| new_hash->flags = hash->flags; |
| |
| /* Empty hash? */ |
| if (ftrace_hash_empty(hash)) |
| return new_hash; |
| |
| size = 1 << hash->size_bits; |
| for (i = 0; i < size; i++) { |
| hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
| ret = add_hash_entry(new_hash, entry->ip); |
| if (ret < 0) |
| goto free_hash; |
| } |
| } |
| |
| FTRACE_WARN_ON(new_hash->count != hash->count); |
| |
| return new_hash; |
| |
| free_hash: |
| free_ftrace_hash(new_hash); |
| return NULL; |
| } |
| |
| static void |
| ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
| static void |
| ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
| |
| static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
| struct ftrace_hash *new_hash); |
| |
| static struct ftrace_hash * |
| __ftrace_hash_move(struct ftrace_hash *src) |
| { |
| struct ftrace_func_entry *entry; |
| struct hlist_node *tn; |
| struct hlist_head *hhd; |
| struct ftrace_hash *new_hash; |
| int size = src->count; |
| int bits = 0; |
| int i; |
| |
| /* |
| * If the new source is empty, just return the empty_hash. |
| */ |
| if (ftrace_hash_empty(src)) |
| return EMPTY_HASH; |
| |
| /* |
| * Make the hash size about 1/2 the # found |
| */ |
| for (size /= 2; size; size >>= 1) |
| bits++; |
| |
| /* Don't allocate too much */ |
| if (bits > FTRACE_HASH_MAX_BITS) |
| bits = FTRACE_HASH_MAX_BITS; |
| |
| new_hash = alloc_ftrace_hash(bits); |
| if (!new_hash) |
| return NULL; |
| |
| new_hash->flags = src->flags; |
| |
| size = 1 << src->size_bits; |
| for (i = 0; i < size; i++) { |
| hhd = &src->buckets[i]; |
| hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
| remove_hash_entry(src, entry); |
| __add_hash_entry(new_hash, entry); |
| } |
| } |
| |
| return new_hash; |
| } |
| |
| static int |
| ftrace_hash_move(struct ftrace_ops *ops, int enable, |
| struct ftrace_hash **dst, struct ftrace_hash *src) |
| { |
| struct ftrace_hash *new_hash; |
| int ret; |
| |
| /* Reject setting notrace hash on IPMODIFY ftrace_ops */ |
| if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) |
| return -EINVAL; |
| |
| new_hash = __ftrace_hash_move(src); |
| if (!new_hash) |
| return -ENOMEM; |
| |
| /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
| if (enable) { |
| /* IPMODIFY should be updated only when filter_hash updating */ |
| ret = ftrace_hash_ipmodify_update(ops, new_hash); |
| if (ret < 0) { |
| free_ftrace_hash(new_hash); |
| return ret; |
| } |
| } |
| |
| /* |
| * Remove the current set, update the hash and add |
| * them back. |
| */ |
| ftrace_hash_rec_disable_modify(ops, enable); |
| |
| rcu_assign_pointer(*dst, new_hash); |
| |
| ftrace_hash_rec_enable_modify(ops, enable); |
| |
| return 0; |
| } |
| |
| static bool hash_contains_ip(unsigned long ip, |
| struct ftrace_ops_hash *hash) |
| { |
| /* |
| * The function record is a match if it exists in the filter |
| * hash and not in the notrace hash. Note, an emty hash is |
| * considered a match for the filter hash, but an empty |
| * notrace hash is considered not in the notrace hash. |
| */ |
| return (ftrace_hash_empty(hash->filter_hash) || |
| __ftrace_lookup_ip(hash->filter_hash, ip)) && |
| (ftrace_hash_empty(hash->notrace_hash) || |
| !__ftrace_lookup_ip(hash->notrace_hash, ip)); |
| } |
| |
| /* |
| * Test the hashes for this ops to see if we want to call |
| * the ops->func or not. |
| * |
| * It's a match if the ip is in the ops->filter_hash or |
| * the filter_hash does not exist or is empty, |
| * AND |
| * the ip is not in the ops->notrace_hash. |
| * |
| * This needs to be called with preemption disabled as |
| * the hashes are freed with call_rcu_sched(). |
| */ |
| static int |
| ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
| { |
| struct ftrace_ops_hash hash; |
| int ret; |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
| /* |
| * There's a small race when adding ops that the ftrace handler |
| * that wants regs, may be called without them. We can not |
| * allow that handler to be called if regs is NULL. |
| */ |
| if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) |
| return 0; |
| #endif |
| |
| rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash); |
| rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash); |
| |
| if (hash_contains_ip(ip, &hash)) |
| ret = 1; |
| else |
| ret = 0; |
| |
| return ret; |
| } |
| |
| /* |
| * This is a double for. Do not use 'break' to break out of the loop, |
| * you must use a goto. |
| */ |
| #define do_for_each_ftrace_rec(pg, rec) \ |
| for (pg = ftrace_pages_start; pg; pg = pg->next) { \ |
| int _____i; \ |
| for (_____i = 0; _____i < pg->index; _____i++) { \ |
| rec = &pg->records[_____i]; |
| |
| #define while_for_each_ftrace_rec() \ |
| } \ |
| } |
| |
| |
| static int ftrace_cmp_recs(const void *a, const void *b) |
| { |
| const struct dyn_ftrace *key = a; |
| const struct dyn_ftrace *rec = b; |
| |
| if (key->flags < rec->ip) |
| return -1; |
| if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
| return 1; |
| return 0; |
| } |
| |
| /** |
| * ftrace_location_range - return the first address of a traced location |
| * if it touches the given ip range |
| * @start: start of range to search. |
| * @end: end of range to search (inclusive). @end points to the last byte |
| * to check. |
| * |
| * Returns rec->ip if the related ftrace location is a least partly within |
| * the given address range. That is, the first address of the instruction |
| * that is either a NOP or call to the function tracer. It checks the ftrace |
| * internal tables to determine if the address belongs or not. |
| */ |
| unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
| { |
| struct ftrace_page *pg; |
| struct dyn_ftrace *rec; |
| struct dyn_ftrace key; |
| |
| key.ip = start; |
| key.flags = end; /* overload flags, as it is unsigned long */ |
| |
| for (pg = ftrace_pages_start; pg; pg = pg->next) { |
| if (end < pg->records[0].ip || |
| start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) |
| continue; |
| rec = bsearch(&key, pg->records, pg->index, |
| sizeof(struct dyn_ftrace), |
| ftrace_cmp_recs); |
| if (rec) |
| return rec->ip; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * ftrace_location - return true if the ip giving is a traced location |
| * @ip: the instruction pointer to check |
| * |
| * Returns rec->ip if @ip given is a pointer to a ftrace location. |
| * That is, the instruction that is either a NOP or call to |
| * the function tracer. It checks the ftrace internal tables to |
| * determine if the address belongs or not. |
| */ |
| unsigned long ftrace_location(unsigned long ip) |
| { |
| return ftrace_location_range(ip, ip); |
| } |
| |
| /** |
| * ftrace_text_reserved - return true if range contains an ftrace location |
| * @start: start of range to search |
| * @end: end of range to search (inclusive). @end points to the last byte to check. |
| * |
| * Returns 1 if @start and @end contains a ftrace location. |
| * That is, the instruction that is either a NOP or call to |
| * the function tracer. It checks the ftrace internal tables to |
| * determine if the address belongs or not. |
| */ |
| int ftrace_text_reserved(const void *start, const void *end) |
| { |
| unsigned long ret; |
| |
| ret = ftrace_location_range((unsigned long)start, |
| (unsigned long)end); |
| |
| return (int)!!ret; |
| } |
| |
| /* Test if ops registered to this rec needs regs */ |
| static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *ops; |
| bool keep_regs = false; |
| |
| for (ops = ftrace_ops_list; |
| ops != &ftrace_list_end; ops = ops->next) { |
| /* pass rec in as regs to have non-NULL val */ |
| if (ftrace_ops_test(ops, rec->ip, rec)) { |
| if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { |
| keep_regs = true; |
| break; |
| } |
| } |
| } |
| |
| return keep_regs; |
| } |
| |
| static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, |
| int filter_hash, |
| bool inc) |
| { |
| struct ftrace_hash *hash; |
| struct ftrace_hash *other_hash; |
| struct ftrace_page *pg; |
| struct dyn_ftrace *rec; |
| bool update = false; |
| int count = 0; |
| int all = false; |
| |
| /* Only update if the ops has been registered */ |
| if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) |
| return false; |
| |
| /* |
| * In the filter_hash case: |
| * If the count is zero, we update all records. |
| * Otherwise we just update the items in the hash. |
| * |
| * In the notrace_hash case: |
| * We enable the update in the hash. |
| * As disabling notrace means enabling the tracing, |
| * and enabling notrace means disabling, the inc variable |
| * gets inversed. |
| */ |
| if (filter_hash) { |
| hash = ops->func_hash->filter_hash; |
| other_hash = ops->func_hash->notrace_hash; |
| if (ftrace_hash_empty(hash)) |
| all = true; |
| } else { |
| inc = !inc; |
| hash = ops->func_hash->notrace_hash; |
| other_hash = ops->func_hash->filter_hash; |
| /* |
| * If the notrace hash has no items, |
| * then there's nothing to do. |
| */ |
| if (ftrace_hash_empty(hash)) |
| return false; |
| } |
| |
| do_for_each_ftrace_rec(pg, rec) { |
| int in_other_hash = 0; |
| int in_hash = 0; |
| int match = 0; |
| |
| if (rec->flags & FTRACE_FL_DISABLED) |
| continue; |
| |
| if (all) { |
| /* |
| * Only the filter_hash affects all records. |
| * Update if the record is not in the notrace hash. |
| */ |
| if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
| match = 1; |
| } else { |
| in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
| in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); |
| |
| /* |
| * If filter_hash is set, we want to match all functions |
| * that are in the hash but not in the other hash. |
| * |
| * If filter_hash is not set, then we are decrementing. |
| * That means we match anything that is in the hash |
| * and also in the other_hash. That is, we need to turn |
| * off functions in the other hash because they are disabled |
| * by this hash. |
| */ |
| if (filter_hash && in_hash && !in_other_hash) |
| match = 1; |
| else if (!filter_hash && in_hash && |
| (in_other_hash || ftrace_hash_empty(other_hash))) |
| match = 1; |
| } |
| if (!match) |
| continue; |
| |
| if (inc) { |
| rec->flags++; |
| if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
| return false; |
| |
| /* |
| * If there's only a single callback registered to a |
| * function, and the ops has a trampoline registered |
| * for it, then we can call it directly. |
| */ |
| if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
| rec->flags |= FTRACE_FL_TRAMP; |
| else |
| /* |
| * If we are adding another function callback |
| * to this function, and the previous had a |
| * custom trampoline in use, then we need to go |
| * back to the default trampoline. |
| */ |
| rec->flags &= ~FTRACE_FL_TRAMP; |
| |
| /* |
| * If any ops wants regs saved for this function |
| * then all ops will get saved regs. |
| */ |
| if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) |
| rec->flags |= FTRACE_FL_REGS; |
| } else { |
| if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
| return false; |
| rec->flags--; |
| |
| /* |
| * If the rec had REGS enabled and the ops that is |
| * being removed had REGS set, then see if there is |
| * still any ops for this record that wants regs. |
| * If not, we can stop recording them. |
| */ |
| if (ftrace_rec_count(rec) > 0 && |
| rec->flags & FTRACE_FL_REGS && |
| ops->flags & FTRACE_OPS_FL_SAVE_REGS) { |
| if (!test_rec_ops_needs_regs(rec)) |
| rec->flags &= ~FTRACE_FL_REGS; |
| } |
| |
| /* |
| * If the rec had TRAMP enabled, then it needs to |
| * be cleared. As TRAMP can only be enabled iff |
| * there is only a single ops attached to it. |
| * In otherwords, always disable it on decrementing. |
| * In the future, we may set it if rec count is |
| * decremented to one, and the ops that is left |
| * has a trampoline. |
| */ |
| rec->flags &= ~FTRACE_FL_TRAMP; |
| |
| /* |
| * flags will be cleared in ftrace_check_record() |
| * if rec count is zero. |
| */ |
| } |
| count++; |
| |
| /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ |
| update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE; |
| |
| /* Shortcut, if we handled all records, we are done. */ |
| if (!all && count == hash->count) |
| return update; |
| } while_for_each_ftrace_rec(); |
| |
| return update; |
| } |
| |
| static bool ftrace_hash_rec_disable(struct ftrace_ops *ops, |
| int filter_hash) |
| { |
| return __ftrace_hash_rec_update(ops, filter_hash, 0); |
| } |
| |
| static bool ftrace_hash_rec_enable(struct ftrace_ops *ops, |
| int filter_hash) |
| { |
| return __ftrace_hash_rec_update(ops, filter_hash, 1); |
| } |
| |
| static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
| int filter_hash, int inc) |
| { |
| struct ftrace_ops *op; |
| |
| __ftrace_hash_rec_update(ops, filter_hash, inc); |
| |
| if (ops->func_hash != &global_ops.local_hash) |
| return; |
| |
| /* |
| * If the ops shares the global_ops hash, then we need to update |
| * all ops that are enabled and use this hash. |
| */ |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| /* Already done */ |
| if (op == ops) |
| continue; |
| if (op->func_hash == &global_ops.local_hash) |
| __ftrace_hash_rec_update(op, filter_hash, inc); |
| } while_for_each_ftrace_op(op); |
| } |
| |
| static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, |
| int filter_hash) |
| { |
| ftrace_hash_rec_update_modify(ops, filter_hash, 0); |
| } |
| |
| static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, |
| int filter_hash) |
| { |
| ftrace_hash_rec_update_modify(ops, filter_hash, 1); |
| } |
| |
| /* |
| * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK |
| * or no-needed to update, -EBUSY if it detects a conflict of the flag |
| * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. |
| * Note that old_hash and new_hash has below meanings |
| * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) |
| * - If the hash is EMPTY_HASH, it hits nothing |
| * - Anything else hits the recs which match the hash entries. |
| */ |
| static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, |
| struct ftrace_hash *old_hash, |
| struct ftrace_hash *new_hash) |
| { |
| struct ftrace_page *pg; |
| struct dyn_ftrace *rec, *end = NULL; |
| int in_old, in_new; |
| |
| /* Only update if the ops has been registered */ |
| if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) |
| return 0; |
| |
| if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) |
| return 0; |
| |
| /* |
| * Since the IPMODIFY is a very address sensitive action, we do not |
| * allow ftrace_ops to set all functions to new hash. |
| */ |
| if (!new_hash || !old_hash) |
| return -EINVAL; |
| |
| /* Update rec->flags */ |
| do_for_each_ftrace_rec(pg, rec) { |
| |
| if (rec->flags & FTRACE_FL_DISABLED) |
| continue; |
| |
| /* We need to update only differences of filter_hash */ |
| in_old = !!ftrace_lookup_ip(old_hash, rec->ip); |
| in_new = !!ftrace_lookup_ip(new_hash, rec->ip); |
| if (in_old == in_new) |
| continue; |
| |
| if (in_new) { |
| /* New entries must ensure no others are using it */ |
| if (rec->flags & FTRACE_FL_IPMODIFY) |
| goto rollback; |
| rec->flags |= FTRACE_FL_IPMODIFY; |
| } else /* Removed entry */ |
| rec->flags &= ~FTRACE_FL_IPMODIFY; |
| } while_for_each_ftrace_rec(); |
| |
| return 0; |
| |
| rollback: |
| end = rec; |
| |
| /* Roll back what we did above */ |
| do_for_each_ftrace_rec(pg, rec) { |
| |
| if (rec->flags & FTRACE_FL_DISABLED) |
| continue; |
| |
| if (rec == end) |
| goto err_out; |
| |
| in_old = !!ftrace_lookup_ip(old_hash, rec->ip); |
| in_new = !!ftrace_lookup_ip(new_hash, rec->ip); |
| if (in_old == in_new) |
| continue; |
| |
| if (in_new) |
| rec->flags &= ~FTRACE_FL_IPMODIFY; |
| else |
| rec->flags |= FTRACE_FL_IPMODIFY; |
| } while_for_each_ftrace_rec(); |
| |
| err_out: |
| return -EBUSY; |
| } |
| |
| static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) |
| { |
| struct ftrace_hash *hash = ops->func_hash->filter_hash; |
| |
| if (ftrace_hash_empty(hash)) |
| hash = NULL; |
| |
| return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); |
| } |
| |
| /* Disabling always succeeds */ |
| static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) |
| { |
| struct ftrace_hash *hash = ops->func_hash->filter_hash; |
| |
| if (ftrace_hash_empty(hash)) |
| hash = NULL; |
| |
| __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); |
| } |
| |
| static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
| struct ftrace_hash *new_hash) |
| { |
| struct ftrace_hash *old_hash = ops->func_hash->filter_hash; |
| |
| if (ftrace_hash_empty(old_hash)) |
| old_hash = NULL; |
| |
| if (ftrace_hash_empty(new_hash)) |
| new_hash = NULL; |
| |
| return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); |
| } |
| |
| static void print_ip_ins(const char *fmt, const unsigned char *p) |
| { |
| int i; |
| |
| printk(KERN_CONT "%s", fmt); |
| |
| for (i = 0; i < MCOUNT_INSN_SIZE; i++) |
| printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); |
| } |
| |
| static struct ftrace_ops * |
| ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); |
| static struct ftrace_ops * |
| ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); |
| |
| enum ftrace_bug_type ftrace_bug_type; |
| const void *ftrace_expected; |
| |
| static void print_bug_type(void) |
| { |
| switch (ftrace_bug_type) { |
| case FTRACE_BUG_UNKNOWN: |
| break; |
| case FTRACE_BUG_INIT: |
| pr_info("Initializing ftrace call sites\n"); |
| break; |
| case FTRACE_BUG_NOP: |
| pr_info("Setting ftrace call site to NOP\n"); |
| break; |
| case FTRACE_BUG_CALL: |
| pr_info("Setting ftrace call site to call ftrace function\n"); |
| break; |
| case FTRACE_BUG_UPDATE: |
| pr_info("Updating ftrace call site to call a different ftrace function\n"); |
| break; |
| } |
| } |
| |
| /** |
| * ftrace_bug - report and shutdown function tracer |
| * @failed: The failed type (EFAULT, EINVAL, EPERM) |
| * @rec: The record that failed |
| * |
| * The arch code that enables or disables the function tracing |
| * can call ftrace_bug() when it has detected a problem in |
| * modifying the code. @failed should be one of either: |
| * EFAULT - if the problem happens on reading the @ip address |
| * EINVAL - if what is read at @ip is not what was expected |
| * EPERM - if the problem happens on writting to the @ip address |
| */ |
| void ftrace_bug(int failed, struct dyn_ftrace *rec) |
| { |
| unsigned long ip = rec ? rec->ip : 0; |
| |
| switch (failed) { |
| case -EFAULT: |
| FTRACE_WARN_ON_ONCE(1); |
| pr_info("ftrace faulted on modifying "); |
| print_ip_sym(ip); |
| break; |
| case -EINVAL: |
| FTRACE_WARN_ON_ONCE(1); |
| pr_info("ftrace failed to modify "); |
| print_ip_sym(ip); |
| print_ip_ins(" actual: ", (unsigned char *)ip); |
| pr_cont("\n"); |
| if (ftrace_expected) { |
| print_ip_ins(" expected: ", ftrace_expected); |
| pr_cont("\n"); |
| } |
| break; |
| case -EPERM: |
| FTRACE_WARN_ON_ONCE(1); |
| pr_info("ftrace faulted on writing "); |
| print_ip_sym(ip); |
| break; |
| default: |
| FTRACE_WARN_ON_ONCE(1); |
| pr_info("ftrace faulted on unknown error "); |
| print_ip_sym(ip); |
| } |
| print_bug_type(); |
| if (rec) { |
| struct ftrace_ops *ops = NULL; |
| |
| pr_info("ftrace record flags: %lx\n", rec->flags); |
| pr_cont(" (%ld)%s", ftrace_rec_count(rec), |
| rec->flags & FTRACE_FL_REGS ? " R" : " "); |
| if (rec->flags & FTRACE_FL_TRAMP_EN) { |
| ops = ftrace_find_tramp_ops_any(rec); |
| if (ops) { |
| do { |
| pr_cont("\ttramp: %pS (%pS)", |
| (void *)ops->trampoline, |
| (void *)ops->func); |
| ops = ftrace_find_tramp_ops_next(rec, ops); |
| } while (ops); |
| } else |
| pr_cont("\ttramp: ERROR!"); |
| |
| } |
| ip = ftrace_get_addr_curr(rec); |
| pr_cont("\n expected tramp: %lx\n", ip); |
| } |
| } |
| |
| static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
| { |
| unsigned long flag = 0UL; |
| |
| ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
| |
| if (rec->flags & FTRACE_FL_DISABLED) |
| return FTRACE_UPDATE_IGNORE; |
| |
| /* |
| * If we are updating calls: |
| * |
| * If the record has a ref count, then we need to enable it |
| * because someone is using it. |
| * |
| * Otherwise we make sure its disabled. |
| * |
| * If we are disabling calls, then disable all records that |
| * are enabled. |
| */ |
| if (enable && ftrace_rec_count(rec)) |
| flag = FTRACE_FL_ENABLED; |
| |
| /* |
| * If enabling and the REGS flag does not match the REGS_EN, or |
| * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore |
| * this record. Set flags to fail the compare against ENABLED. |
| */ |
| if (flag) { |
| if (!(rec->flags & FTRACE_FL_REGS) != |
| !(rec->flags & FTRACE_FL_REGS_EN)) |
| flag |= FTRACE_FL_REGS; |
| |
| if (!(rec->flags & FTRACE_FL_TRAMP) != |
| !(rec->flags & FTRACE_FL_TRAMP_EN)) |
| flag |= FTRACE_FL_TRAMP; |
| } |
| |
| /* If the state of this record hasn't changed, then do nothing */ |
| if ((rec->flags & FTRACE_FL_ENABLED) == flag) |
| return FTRACE_UPDATE_IGNORE; |
| |
| if (flag) { |
| /* Save off if rec is being enabled (for return value) */ |
| flag ^= rec->flags & FTRACE_FL_ENABLED; |
| |
| if (update) { |
| rec->flags |= FTRACE_FL_ENABLED; |
| if (flag & FTRACE_FL_REGS) { |
| if (rec->flags & FTRACE_FL_REGS) |
| rec->flags |= FTRACE_FL_REGS_EN; |
| else |
| rec->flags &= ~FTRACE_FL_REGS_EN; |
| } |
| if (flag & FTRACE_FL_TRAMP) { |
| if (rec->flags & FTRACE_FL_TRAMP) |
| rec->flags |= FTRACE_FL_TRAMP_EN; |
| else |
| rec->flags &= ~FTRACE_FL_TRAMP_EN; |
| } |
| } |
| |
| /* |
| * If this record is being updated from a nop, then |
| * return UPDATE_MAKE_CALL. |
| * Otherwise, |
| * return UPDATE_MODIFY_CALL to tell the caller to convert |
| * from the save regs, to a non-save regs function or |
| * vice versa, or from a trampoline call. |
| */ |
| if (flag & FTRACE_FL_ENABLED) { |
| ftrace_bug_type = FTRACE_BUG_CALL; |
| return FTRACE_UPDATE_MAKE_CALL; |
| } |
| |
| ftrace_bug_type = FTRACE_BUG_UPDATE; |
| return FTRACE_UPDATE_MODIFY_CALL; |
| } |
| |
| if (update) { |
| /* If there's no more users, clear all flags */ |
| if (!ftrace_rec_count(rec)) |
| rec->flags = 0; |
| else |
| /* |
| * Just disable the record, but keep the ops TRAMP |
| * and REGS states. The _EN flags must be disabled though. |
| */ |
| rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | |
| FTRACE_FL_REGS_EN); |
| } |
| |
| ftrace_bug_type = FTRACE_BUG_NOP; |
| return FTRACE_UPDATE_MAKE_NOP; |
| } |
| |
| /** |
| * ftrace_update_record, set a record that now is tracing or not |
| * @rec: the record to update |
| * @enable: set to 1 if the record is tracing, zero to force disable |
| * |
| * The records that represent all functions that can be traced need |
| * to be updated when tracing has been enabled. |
| */ |
| int ftrace_update_record(struct dyn_ftrace *rec, int enable) |
| { |
| return ftrace_check_record(rec, enable, 1); |
| } |
| |
| /** |
| * ftrace_test_record, check if the record has been enabled or not |
| * @rec: the record to test |
| * @enable: set to 1 to check if enabled, 0 if it is disabled |
| * |
| * The arch code may need to test if a record is already set to |
| * tracing to determine how to modify the function code that it |
| * represents. |
| */ |
| int ftrace_test_record(struct dyn_ftrace *rec, int enable) |
| { |
| return ftrace_check_record(rec, enable, 0); |
| } |
| |
| static struct ftrace_ops * |
| ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *op; |
| unsigned long ip = rec->ip; |
| |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| |
| if (!op->trampoline) |
| continue; |
| |
| if (hash_contains_ip(ip, op->func_hash)) |
| return op; |
| } while_for_each_ftrace_op(op); |
| |
| return NULL; |
| } |
| |
| static struct ftrace_ops * |
| ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, |
| struct ftrace_ops *op) |
| { |
| unsigned long ip = rec->ip; |
| |
| while_for_each_ftrace_op(op) { |
| |
| if (!op->trampoline) |
| continue; |
| |
| if (hash_contains_ip(ip, op->func_hash)) |
| return op; |
| } |
| |
| return NULL; |
| } |
| |
| static struct ftrace_ops * |
| ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *op; |
| unsigned long ip = rec->ip; |
| |
| /* |
| * Need to check removed ops first. |
| * If they are being removed, and this rec has a tramp, |
| * and this rec is in the ops list, then it would be the |
| * one with the tramp. |
| */ |
| if (removed_ops) { |
| if (hash_contains_ip(ip, &removed_ops->old_hash)) |
| return removed_ops; |
| } |
| |
| /* |
| * Need to find the current trampoline for a rec. |
| * Now, a trampoline is only attached to a rec if there |
| * was a single 'ops' attached to it. But this can be called |
| * when we are adding another op to the rec or removing the |
| * current one. Thus, if the op is being added, we can |
| * ignore it because it hasn't attached itself to the rec |
| * yet. |
| * |
| * If an ops is being modified (hooking to different functions) |
| * then we don't care about the new functions that are being |
| * added, just the old ones (that are probably being removed). |
| * |
| * If we are adding an ops to a function that already is using |
| * a trampoline, it needs to be removed (trampolines are only |
| * for single ops connected), then an ops that is not being |
| * modified also needs to be checked. |
| */ |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| |
| if (!op->trampoline) |
| continue; |
| |
| /* |
| * If the ops is being added, it hasn't gotten to |
| * the point to be removed from this tree yet. |
| */ |
| if (op->flags & FTRACE_OPS_FL_ADDING) |
| continue; |
| |
| |
| /* |
| * If the ops is being modified and is in the old |
| * hash, then it is probably being removed from this |
| * function. |
| */ |
| if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
| hash_contains_ip(ip, &op->old_hash)) |
| return op; |
| /* |
| * If the ops is not being added or modified, and it's |
| * in its normal filter hash, then this must be the one |
| * we want! |
| */ |
| if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && |
| hash_contains_ip(ip, op->func_hash)) |
| return op; |
| |
| } while_for_each_ftrace_op(op); |
| |
| return NULL; |
| } |
| |
| static struct ftrace_ops * |
| ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *op; |
| unsigned long ip = rec->ip; |
| |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| /* pass rec in as regs to have non-NULL val */ |
| if (hash_contains_ip(ip, op->func_hash)) |
| return op; |
| } while_for_each_ftrace_op(op); |
| |
| return NULL; |
| } |
| |
| /** |
| * ftrace_get_addr_new - Get the call address to set to |
| * @rec: The ftrace record descriptor |
| * |
| * If the record has the FTRACE_FL_REGS set, that means that it |
| * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS |
| * is not not set, then it wants to convert to the normal callback. |
| * |
| * Returns the address of the trampoline to set to |
| */ |
| unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *ops; |
| |
| /* Trampolines take precedence over regs */ |
| if (rec->flags & FTRACE_FL_TRAMP) { |
| ops = ftrace_find_tramp_ops_new(rec); |
| if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { |
| pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
| (void *)rec->ip, (void *)rec->ip, rec->flags); |
| /* Ftrace is shutting down, return anything */ |
| return (unsigned long)FTRACE_ADDR; |
| } |
| return ops->trampoline; |
| } |
| |
| if (rec->flags & FTRACE_FL_REGS) |
| return (unsigned long)FTRACE_REGS_ADDR; |
| else |
| return (unsigned long)FTRACE_ADDR; |
| } |
| |
| /** |
| * ftrace_get_addr_curr - Get the call address that is already there |
| * @rec: The ftrace record descriptor |
| * |
| * The FTRACE_FL_REGS_EN is set when the record already points to |
| * a function that saves all the regs. Basically the '_EN' version |
| * represents the current state of the function. |
| * |
| * Returns the address of the trampoline that is currently being called |
| */ |
| unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *ops; |
| |
| /* Trampolines take precedence over regs */ |
| if (rec->flags & FTRACE_FL_TRAMP_EN) { |
| ops = ftrace_find_tramp_ops_curr(rec); |
| if (FTRACE_WARN_ON(!ops)) { |
| pr_warn("Bad trampoline accounting at: %p (%pS)\n", |
| (void *)rec->ip, (void *)rec->ip); |
| /* Ftrace is shutting down, return anything */ |
| return (unsigned long)FTRACE_ADDR; |
| } |
| return ops->trampoline; |
| } |
| |
| if (rec->flags & FTRACE_FL_REGS_EN) |
| return (unsigned long)FTRACE_REGS_ADDR; |
| else |
| return (unsigned long)FTRACE_ADDR; |
| } |
| |
| static int |
| __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
| { |
| unsigned long ftrace_old_addr; |
| unsigned long ftrace_addr; |
| int ret; |
| |
| ftrace_addr = ftrace_get_addr_new(rec); |
| |
| /* This needs to be done before we call ftrace_update_record */ |
| ftrace_old_addr = ftrace_get_addr_curr(rec); |
| |
| ret = ftrace_update_record(rec, enable); |
| |
| ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
| |
| switch (ret) { |
| case FTRACE_UPDATE_IGNORE: |
| return 0; |
| |
| case FTRACE_UPDATE_MAKE_CALL: |
| ftrace_bug_type = FTRACE_BUG_CALL; |
| return ftrace_make_call(rec, ftrace_addr); |
| |
| case FTRACE_UPDATE_MAKE_NOP: |
| ftrace_bug_type = FTRACE_BUG_NOP; |
| return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
| |
| case FTRACE_UPDATE_MODIFY_CALL: |
| ftrace_bug_type = FTRACE_BUG_UPDATE; |
| return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
| } |
| |
| return -1; /* unknow ftrace bug */ |
| } |
| |
| void __weak ftrace_replace_code(int enable) |
| { |
| struct dyn_ftrace *rec; |
| struct ftrace_page *pg; |
| int failed; |
| |
| if (unlikely(ftrace_disabled)) |
| return; |
| |
| do_for_each_ftrace_rec(pg, rec) { |
| |
| if (rec->flags & FTRACE_FL_DISABLED) |
| continue; |
| |
| failed = __ftrace_replace_code(rec, enable); |
| if (failed) { |
| ftrace_bug(failed, rec); |
| /* Stop processing */ |
| return; |
| } |
| } while_for_each_ftrace_rec(); |
| } |
| |
| struct ftrace_rec_iter { |
| struct ftrace_page *pg; |
| int index; |
| }; |
| |
| /** |
| * ftrace_rec_iter_start, start up iterating over traced functions |
| * |
| * Returns an iterator handle that is used to iterate over all |
| * the records that represent address locations where functions |
| * are traced. |
| * |
| * May return NULL if no records are available. |
| */ |
| struct ftrace_rec_iter *ftrace_rec_iter_start(void) |
| { |
| /* |
| * We only use a single iterator. |
| * Protected by the ftrace_lock mutex. |
| */ |
| static struct ftrace_rec_iter ftrace_rec_iter; |
| struct ftrace_rec_iter *iter = &ftrace_rec_iter; |
| |
| iter->pg = ftrace_pages_start; |
| iter->index = 0; |
| |
| /* Could have empty pages */ |
| while (iter->pg && !iter->pg->index) |
| iter->pg = iter->pg->next; |
| |
| if (!iter->pg) |
| return NULL; |
| |
| return iter; |
| } |
| |
| /** |
| * ftrace_rec_iter_next, get the next record to process. |
| * @iter: The handle to the iterator. |
| * |
| * Returns the next iterator after the given iterator @iter. |
| */ |
| struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) |
| { |
| iter->index++; |
| |
| if (iter->index >= iter->pg->index) { |
| iter->pg = iter->pg->next; |
| iter->index = 0; |
| |
| /* Could have empty pages */ |
| while (iter->pg && !iter->pg->index) |
| iter->pg = iter->pg->next; |
| } |
| |
| if (!iter->pg) |
| return NULL; |
| |
| return iter; |
| } |
| |
| /** |
| * ftrace_rec_iter_record, get the record at the iterator location |
| * @iter: The current iterator location |
| * |
| * Returns the record that the current @iter is at. |
| */ |
| struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) |
| { |
| return &iter->pg->records[iter->index]; |
| } |
| |
| static int |
| ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
| { |
| int ret; |
| |
| if (unlikely(ftrace_disabled)) |
| return 0; |
| |
| ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
| if (ret) { |
| ftrace_bug_type = FTRACE_BUG_INIT; |
| ftrace_bug(ret, rec); |
| return 0; |
| } |
| return 1; |
| } |
| |
| /* |
| * archs can override this function if they must do something |
| * before the modifying code is performed. |
| */ |
| int __weak ftrace_arch_code_modify_prepare(void) |
| { |
| return 0; |
| } |
| |
| /* |
| * archs can override this function if they must do something |
| * after the modifying code is performed. |
| */ |
| int __weak ftrace_arch_code_modify_post_process(void) |
| { |
| return 0; |
| } |
| |
| void ftrace_modify_all_code(int command) |
| { |
| int update = command & FTRACE_UPDATE_TRACE_FUNC; |
| int err = 0; |
| |
| /* |
| * If the ftrace_caller calls a ftrace_ops func directly, |
| * we need to make sure that it only traces functions it |
| * expects to trace. When doing the switch of functions, |
| * we need to update to the ftrace_ops_list_func first |
| * before the transition between old and new calls are set, |
| * as the ftrace_ops_list_func will check the ops hashes |
| * to make sure the ops are having the right functions |
| * traced. |
| */ |
| if (update) { |
| err = ftrace_update_ftrace_func(ftrace_ops_list_func); |
| if (FTRACE_WARN_ON(err)) |
| return; |
| } |
| |
| if (command & FTRACE_UPDATE_CALLS) |
| ftrace_replace_code(1); |
| else if (command & FTRACE_DISABLE_CALLS) |
| ftrace_replace_code(0); |
| |
| if (update && ftrace_trace_function != ftrace_ops_list_func) { |
| function_trace_op = set_function_trace_op; |
| smp_wmb(); |
| /* If irqs are disabled, we are in stop machine */ |
| if (!irqs_disabled()) |
| smp_call_function(ftrace_sync_ipi, NULL, 1); |
| err = ftrace_update_ftrace_func(ftrace_trace_function); |
| if (FTRACE_WARN_ON(err)) |
| return; |
| } |
| |
| if (command & FTRACE_START_FUNC_RET) |
| err = ftrace_enable_ftrace_graph_caller(); |
| else if (command & FTRACE_STOP_FUNC_RET) |
| err = ftrace_disable_ftrace_graph_caller(); |
| FTRACE_WARN_ON(err); |
| } |
| |
| static int __ftrace_modify_code(void *data) |
| { |
| int *command = data; |
| |
| ftrace_modify_all_code(*command); |
| |
| return 0; |
| } |
| |
| /** |
| * ftrace_run_stop_machine, go back to the stop machine method |
| * @command: The command to tell ftrace what to do |
| * |
| * If an arch needs to fall back to the stop machine method, the |
| * it can call this function. |
| */ |
| void ftrace_run_stop_machine(int command) |
| { |
| stop_machine(__ftrace_modify_code, &command, NULL); |
| } |
| |
| /** |
| * arch_ftrace_update_code, modify the code to trace or not trace |
| * @command: The command that needs to be done |
| * |
| * Archs can override this function if it does not need to |
| * run stop_machine() to modify code. |
| */ |
| void __weak arch_ftrace_update_code(int command) |
| { |
| ftrace_run_stop_machine(command); |
| } |
| |
| static void ftrace_run_update_code(int command) |
| { |
| int ret; |
| |
| ret = ftrace_arch_code_modify_prepare(); |
| FTRACE_WARN_ON(ret); |
| if (ret) |
| return; |
| |
| /* |
| * By default we use stop_machine() to modify the code. |
| * But archs can do what ever they want as long as it |
| * is safe. The stop_machine() is the safest, but also |
| * produces the most overhead. |
| */ |
| arch_ftrace_update_code(command); |
| |
| ret = ftrace_arch_code_modify_post_process(); |
| FTRACE_WARN_ON(ret); |
| } |
| |
| static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
| struct ftrace_ops_hash *old_hash) |
| { |
| ops->flags |= FTRACE_OPS_FL_MODIFYING; |
| ops->old_hash.filter_hash = old_hash->filter_hash; |
| ops->old_hash.notrace_hash = old_hash->notrace_hash; |
| ftrace_run_update_code(command); |
| ops->old_hash.filter_hash = NULL; |
| ops->old_hash.notrace_hash = NULL; |
| ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
| } |
| |
| static ftrace_func_t saved_ftrace_func; |
| static int ftrace_start_up; |
| |
| void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
| { |
| } |
| |
| static void ftrace_startup_enable(int command) |
| { |
| if (saved_ftrace_func != ftrace_trace_function) { |
| saved_ftrace_func = ftrace_trace_function; |
| command |= FTRACE_UPDATE_TRACE_FUNC; |
| } |
| |
| if (!command || !ftrace_enabled) |
| return; |
| |
| ftrace_run_update_code(command); |
| } |
| |
| static void ftrace_startup_all(int command) |
| { |
| update_all_ops = true; |
| ftrace_startup_enable(command); |
| update_all_ops = false; |
| } |
| |
| static int ftrace_startup(struct ftrace_ops *ops, int command) |
| { |
| int ret; |
| |
| if (unlikely(ftrace_disabled)) |
| return -ENODEV; |
| |
| ret = __register_ftrace_function(ops); |
| if (ret) |
| return ret; |
| |
| ftrace_start_up++; |
| |
| /* |
| * Note that ftrace probes uses this to start up |
| * and modify functions it will probe. But we still |
| * set the ADDING flag for modification, as probes |
| * do not have trampolines. If they add them in the |
| * future, then the probes will need to distinguish |
| * between adding and updating probes. |
| */ |
| ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; |
| |
| ret = ftrace_hash_ipmodify_enable(ops); |
| if (ret < 0) { |
| /* Rollback registration process */ |
| __unregister_ftrace_function(ops); |
| ftrace_start_up--; |
| ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
| return ret; |
| } |
| |
| if (ftrace_hash_rec_enable(ops, 1)) |
| command |= FTRACE_UPDATE_CALLS; |
| |
| ftrace_startup_enable(command); |
| |
| ops->flags &= ~FTRACE_OPS_FL_ADDING; |
| |
| return 0; |
| } |
| |
| static int ftrace_shutdown(struct ftrace_ops *ops, int command) |
| { |
| int ret; |
| |
| if (unlikely(ftrace_disabled)) |
| return -ENODEV; |
| |
| ret = __unregister_ftrace_function(ops); |
| if (ret) |
| return ret; |
| |
| ftrace_start_up--; |
| /* |
| * Just warn in case of unbalance, no need to kill ftrace, it's not |
| * critical but the ftrace_call callers may be never nopped again after |
| * further ftrace uses. |
| */ |
| WARN_ON_ONCE(ftrace_start_up < 0); |
| |
| /* Disabling ipmodify never fails */ |
| ftrace_hash_ipmodify_disable(ops); |
| |
| if (ftrace_hash_rec_disable(ops, 1)) |
| command |= FTRACE_UPDATE_CALLS; |
| |
| ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
| |
| if (saved_ftrace_func != ftrace_trace_function) { |
| saved_ftrace_func = ftrace_trace_function; |
| command |= FTRACE_UPDATE_TRACE_FUNC; |
| } |
| |
| if (!command || !ftrace_enabled) { |
| /* |
| * If these are dynamic or per_cpu ops, they still |
| * need their data freed. Since, function tracing is |
| * not currently active, we can just free them |
| * without synchronizing all CPUs. |
| */ |
| if (ops->flags & FTRACE_OPS_FL_DYNAMIC) |
| goto free_ops; |
| |
| return 0; |
| } |
| |
| /* |
| * If the ops uses a trampoline, then it needs to be |
| * tested first on update. |
| */ |
| ops->flags |= FTRACE_OPS_FL_REMOVING; |
| removed_ops = ops; |
| |
| /* The trampoline logic checks the old hashes */ |
| ops->old_hash.filter_hash = ops->func_hash->filter_hash; |
| ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; |
| |
| ftrace_run_update_code(command); |
| |
| /* |
| * If there's no more ops registered with ftrace, run a |
| * sanity check to make sure all rec flags are cleared. |
| */ |
| if (rcu_dereference_protected(ftrace_ops_list, |
| lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { |
| struct ftrace_page *pg; |
| struct dyn_ftrace *rec; |
| |
| do_for_each_ftrace_rec(pg, rec) { |
| if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED)) |
| pr_warn(" %pS flags:%lx\n", |
| (void *)rec->ip, rec->flags); |
| } while_for_each_ftrace_rec(); |
| } |
| |
| ops->old_hash.filter_hash = NULL; |
| ops->old_hash.notrace_hash = NULL; |
| |
| removed_ops = NULL; |
| ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
| |
| /* |
| * Dynamic ops may be freed, we must make sure that all |
| * callers are done before leaving this function. |
| * The same goes for freeing the per_cpu data of the per_cpu |
| * ops. |
| */ |
| if (ops->flags & FTRACE_OPS_FL_DYNAMIC) { |
| /* |
| * We need to do a hard force of sched synchronization. |
| * This is because we use preempt_disable() to do RCU, but |
| * the function tracers can be called where RCU is not watching |
| * (like before user_exit()). We can not rely on the RCU |
| * infrastructure to do the synchronization, thus we must do it |
| * ourselves. |
| */ |
| schedule_on_each_cpu(ftrace_sync); |
| |
| /* |
| * When the kernel is preeptive, tasks can be preempted |
| * while on a ftrace trampoline. Just scheduling a task on |
| * a CPU is not good enough to flush them. Calling |
| * synchornize_rcu_tasks() will wait for those tasks to |
| * execute and either schedule voluntarily or enter user space. |
| */ |
| if (IS_ENABLED(CONFIG_PREEMPT)) |
| synchronize_rcu_tasks(); |
| |
| free_ops: |
| arch_ftrace_trampoline_free(ops); |
| } |
| |
| return 0; |
| } |
| |
| static void ftrace_startup_sysctl(void) |
| { |
| int command; |
| |
| if (unlikely(ftrace_disabled)) |
| return; |
| |
| /* Force update next time */ |
| saved_ftrace_func = NULL; |
| /* ftrace_start_up is true if we want ftrace running */ |
| if (ftrace_start_up) { |
| command = FTRACE_UPDATE_CALLS; |
| if (ftrace_graph_active) |
| command |= FTRACE_START_FUNC_RET; |
| ftrace_startup_enable(command); |
| } |
| } |
| |
| static void ftrace_shutdown_sysctl(void) |
| { |
| int command; |
| |
| if (unlikely(ftrace_disabled)) |
| return; |
| |
| /* ftrace_start_up is true if ftrace is running */ |
| if (ftrace_start_up) { |
| command = FTRACE_DISABLE_CALLS; |
| if (ftrace_graph_active) |
| command |= FTRACE_STOP_FUNC_RET; |
| ftrace_run_update_code(command); |
| } |
| } |
| |
| static u64 ftrace_update_time; |
| unsigned long ftrace_update_tot_cnt; |
| |
| static inline int ops_traces_mod(struct ftrace_ops *ops) |
| { |
| /* |
| * Filter_hash being empty will default to trace module. |
| * But notrace hash requires a test of individual module functions. |
| */ |
| return ftrace_hash_empty(ops->func_hash->filter_hash) && |
| ftrace_hash_empty(ops->func_hash->notrace_hash); |
| } |
| |
| /* |
| * Check if the current ops references the record. |
| * |
| * If the ops traces all functions, then it was already accounted for. |
| * If the ops does not trace the current record function, skip it. |
| * If the ops ignores the function via notrace filter, skip it. |
| */ |
| static inline bool |
| ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) |
| { |
| /* If ops isn't enabled, ignore it */ |
| if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) |
| return 0; |
| |
| /* If ops traces all then it includes this function */ |
| if (ops_traces_mod(ops)) |
| return 1; |
| |
| /* The function must be in the filter */ |
| if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
| !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) |
| return 0; |
| |
| /* If in notrace hash, we ignore it too */ |
| if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
| return 0; |
| |
| return 1; |
| } |
| |
| static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
| { |
| struct ftrace_page *pg; |
| struct dyn_ftrace *p; |
| u64 start, stop; |
| unsigned long update_cnt = 0; |
| unsigned long rec_flags = 0; |
| int i; |
| |
| start = ftrace_now(raw_smp_processor_id()); |
| |
| /* |
| * When a module is loaded, this function is called to convert |
| * the calls to mcount in its text to nops, and also to create |
| * an entry in the ftrace data. Now, if ftrace is activated |
| * after this call, but before the module sets its text to |
| * read-only, the modification of enabling ftrace can fail if |
| * the read-only is done while ftrace is converting the calls. |
| * To prevent this, the module's records are set as disabled |
| * and will be enabled after the call to set the module's text |
| * to read-only. |
| */ |
| if (mod) |
| rec_flags |= FTRACE_FL_DISABLED; |
| |
| for (pg = new_pgs; pg; pg = pg->next) { |
| |
| for (i = 0; i < pg->index; i++) { |
| |
| /* If something went wrong, bail without enabling anything */ |
| if (unlikely(ftrace_disabled)) |
| return -1; |
| |
| p = &pg->records[i]; |
| p->flags = rec_flags; |
| |
| /* |
| * Do the initial record conversion from mcount jump |
| * to the NOP instructions. |
| */ |
| if (!ftrace_code_disable(mod, p)) |
| break; |
| |
| update_cnt++; |
| } |
| } |
| |
| stop = ftrace_now(raw_smp_processor_id()); |
| ftrace_update_time = stop - start; |
| ftrace_update_tot_cnt += update_cnt; |
| |
| return 0; |
| } |
| |
| static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
| { |
| int order; |
| int cnt; |
| |
| if (WARN_ON(!count)) |
| return -EINVAL; |
| |
| order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); |
| |
| /* |
| * We want to fill as much as possible. No more than a page |
| * may be empty. |
| */ |
| while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
| order--; |
| |
| again: |
| pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); |
| |
| if (!pg->records) { |
| /* if we can't allocate this size, try something smaller */ |
| if (!order) |
| return -ENOMEM; |
| order >>= 1; |
| goto again; |
| } |
| |
| cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
| pg->size = cnt; |
| |
| if (cnt > count) |
| cnt = count; |
| |
| return cnt; |
| } |
| |
| static struct ftrace_page * |
| ftrace_allocate_pages(unsigned long num_to_init) |
| { |
| struct ftrace_page *start_pg; |
| struct ftrace_page *pg; |
| int order; |
| int cnt; |
| |
| if (!num_to_init) |
| return 0; |
| |
| start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
| if (!pg) |
| return NULL; |
| |
| /* |
| * Try to allocate as much as possible in one continues |
| * location that fills in all of the space. We want to |
| * waste as little space as possible. |
| */ |
| for (;;) { |
| cnt = ftrace_allocate_records(pg, num_to_init); |
| if (cnt < 0) |
| goto free_pages; |
| |
| num_to_init -= cnt; |
| if (!num_to_init) |
| break; |
| |
| pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
| if (!pg->next) |
| goto free_pages; |
| |
| pg = pg->next; |
| } |
| |
| return start_pg; |
| |
| free_pages: |
| pg = start_pg; |
| while (pg) { |
| order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
| free_pages((unsigned long)pg->records, order); |
| start_pg = pg->next; |
| kfree(pg); |
| pg = start_pg; |
| } |
| pr_info("ftrace: FAILED to allocate memory for functions\n"); |
| return NULL; |
| } |
| |
| #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
| |
| struct ftrace_iterator { |
| loff_t pos; |
| loff_t func_pos; |
| loff_t mod_pos; |
| struct ftrace_page *pg; |
| struct dyn_ftrace *func; |
| struct ftrace_func_probe *probe; |
| struct ftrace_func_entry *probe_entry; |
| struct trace_parser parser; |
| struct ftrace_hash *hash; |
| struct ftrace_ops *ops; |
| struct trace_array *tr; |
| struct list_head *mod_list; |
| int pidx; |
| int idx; |
| unsigned flags; |
| }; |
| |
| static void * |
| t_probe_next(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| struct trace_array *tr = iter->ops->private; |
| struct list_head *func_probes; |
| struct ftrace_hash *hash; |
| struct list_head *next; |
| struct hlist_node *hnd = NULL; |
| struct hlist_head *hhd; |
| int size; |
| |
| (*pos)++; |
| iter->pos = *pos; |
| |
| if (!tr) |
| return NULL; |
| |
| func_probes = &tr->func_probes; |
| if (list_empty(func_probes)) |
| return NULL; |
| |
| if (!iter->probe) { |
| next = func_probes->next; |
| iter->probe = list_entry(next, struct ftrace_func_probe, list); |
| } |
| |
| if (iter->probe_entry) |
| hnd = &iter->probe_entry->hlist; |
| |
| hash = iter->probe->ops.func_hash->filter_hash; |
| size = 1 << hash->size_bits; |
| |
| retry: |
| if (iter->pidx >= size) { |
| if (iter->probe->list.next == func_probes) |
| return NULL; |
| next = iter->probe->list.next; |
| iter->probe = list_entry(next, struct ftrace_func_probe, list); |
| hash = iter->probe->ops.func_hash->filter_hash; |
| size = 1 << hash->size_bits; |
| iter->pidx = 0; |
| } |
| |
| hhd = &hash->buckets[iter->pidx]; |
| |
| if (hlist_empty(hhd)) { |
| iter->pidx++; |
| hnd = NULL; |
| goto retry; |
| } |
| |
| if (!hnd) |
| hnd = hhd->first; |
| else { |
| hnd = hnd->next; |
| if (!hnd) { |
| iter->pidx++; |
| goto retry; |
| } |
| } |
| |
| if (WARN_ON_ONCE(!hnd)) |
| return NULL; |
| |
| iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist); |
| |
| return iter; |
| } |
| |
| static void *t_probe_start(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| void *p = NULL; |
| loff_t l; |
| |
| if (!(iter->flags & FTRACE_ITER_DO_PROBES)) |
| return NULL; |
| |
| if (iter->mod_pos > *pos) |
| return NULL; |
| |
| iter->probe = NULL; |
| iter->probe_entry = NULL; |
| iter->pidx = 0; |
| for (l = 0; l <= (*pos - iter->mod_pos); ) { |
| p = t_probe_next(m, &l); |
| if (!p) |
| break; |
| } |
| if (!p) |
| return NULL; |
| |
| /* Only set this if we have an item */ |
| iter->flags |= FTRACE_ITER_PROBE; |
| |
| return iter; |
| } |
| |
| static int |
| t_probe_show(struct seq_file *m, struct ftrace_iterator *iter) |
| { |
| struct ftrace_func_entry *probe_entry; |
| struct ftrace_probe_ops *probe_ops; |
| struct ftrace_func_probe *probe; |
| |
| probe = iter->probe; |
| probe_entry = iter->probe_entry; |
| |
| if (WARN_ON_ONCE(!probe || !probe_entry)) |
| return -EIO; |
| |
| probe_ops = probe->probe_ops; |
| |
| if (probe_ops->print) |
| return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data); |
| |
| seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip, |
| (void *)probe_ops->func); |
| |
| return 0; |
| } |
| |
| static void * |
| t_mod_next(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| struct trace_array *tr = iter->tr; |
| |
| (*pos)++; |
| iter->pos = *pos; |
| |
| iter->mod_list = iter->mod_list->next; |
| |
| if (iter->mod_list == &tr->mod_trace || |
| iter->mod_list == &tr->mod_notrace) { |
| iter->flags &= ~FTRACE_ITER_MOD; |
| return NULL; |
| } |
| |
| iter->mod_pos = *pos; |
| |
| return iter; |
| } |
| |
| static void *t_mod_start(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| void *p = NULL; |
| loff_t l; |
| |
| if (iter->func_pos > *pos) |
| return NULL; |
| |
| iter->mod_pos = iter->func_pos; |
| |
| /* probes are only available if tr is set */ |
| if (!iter->tr) |
| return NULL; |
| |
| for (l = 0; l <= (*pos - iter->func_pos); ) { |
| p = t_mod_next(m, &l); |
| if (!p) |
| break; |
| } |
| if (!p) { |
| iter->flags &= ~FTRACE_ITER_MOD; |
| return t_probe_start(m, pos); |
| } |
| |
| /* Only set this if we have an item */ |
| iter->flags |= FTRACE_ITER_MOD; |
| |
| return iter; |
| } |
| |
| static int |
| t_mod_show(struct seq_file *m, struct ftrace_iterator *iter) |
| { |
| struct ftrace_mod_load *ftrace_mod; |
| struct trace_array *tr = iter->tr; |
| |
| if (WARN_ON_ONCE(!iter->mod_list) || |
| iter->mod_list == &tr->mod_trace || |
| iter->mod_list == &tr->mod_notrace) |
| return -EIO; |
| |
| ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list); |
| |
| if (ftrace_mod->func) |
| seq_printf(m, "%s", ftrace_mod->func); |
| else |
| seq_putc(m, '*'); |
| |
| seq_printf(m, ":mod:%s\n", ftrace_mod->module); |
| |
| return 0; |
| } |
| |
| static void * |
| t_func_next(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| struct dyn_ftrace *rec = NULL; |
| |
| (*pos)++; |
| |
| retry: |
| if (iter->idx >= iter->pg->index) { |
| if (iter->pg->next) { |
| iter->pg = iter->pg->next; |
| iter->idx = 0; |
| goto retry; |
| } |
| } else { |
| rec = &iter->pg->records[iter->idx++]; |
| if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
| !ftrace_lookup_ip(iter->hash, rec->ip)) || |
| |
| ((iter->flags & FTRACE_ITER_ENABLED) && |
| !(rec->flags & FTRACE_FL_ENABLED))) { |
| |
| rec = NULL; |
| goto retry; |
| } |
| } |
| |
| if (!rec) |
| return NULL; |
| |
| iter->pos = iter->func_pos = *pos; |
| iter->func = rec; |
| |
| return iter; |
| } |
| |
| static void * |
| t_next(struct seq_file *m, void *v, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| loff_t l = *pos; /* t_probe_start() must use original pos */ |
| void *ret; |
| |
| if (unlikely(ftrace_disabled)) |
| return NULL; |
| |
| if (iter->flags & FTRACE_ITER_PROBE) |
| return t_probe_next(m, pos); |
| |
| if (iter->flags & FTRACE_ITER_MOD) |
| return t_mod_next(m, pos); |
| |
| if (iter->flags & FTRACE_ITER_PRINTALL) { |
| /* next must increment pos, and t_probe_start does not */ |
| (*pos)++; |
| return t_mod_start(m, &l); |
| } |
| |
| ret = t_func_next(m, pos); |
| |
| if (!ret) |
| return t_mod_start(m, &l); |
| |
| return ret; |
| } |
| |
| static void reset_iter_read(struct ftrace_iterator *iter) |
| { |
| iter->pos = 0; |
| iter->func_pos = 0; |
| iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD); |
| } |
| |
| static void *t_start(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| void *p = NULL; |
| loff_t l; |
| |
| mutex_lock(&ftrace_lock); |
| |
| if (unlikely(ftrace_disabled)) |
| return NULL; |
| |
| /* |
| * If an lseek was done, then reset and start from beginning. |
| */ |
| if (*pos < iter->pos) |
| reset_iter_read(iter); |
| |
| /* |
| * For set_ftrace_filter reading, if we have the filter |
| * off, we can short cut and just print out that all |
| * functions are enabled. |
| */ |
| if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
| ftrace_hash_empty(iter->hash)) { |
| iter->func_pos = 1; /* Account for the message */ |
| if (*pos > 0) |
| return t_mod_start(m, pos); |
| iter->flags |= FTRACE_ITER_PRINTALL; |
| /* reset in case of seek/pread */ |
| iter->flags &= ~FTRACE_ITER_PROBE; |
| return iter; |
| } |
| |
| if (iter->flags & FTRACE_ITER_MOD) |
| return t_mod_start(m, pos); |
| |
| /* |
| * Unfortunately, we need to restart at ftrace_pages_start |
| * every time we let go of the ftrace_mutex. This is because |
| * those pointers can change without the lock. |
| */ |
| iter->pg = ftrace_pages_start; |
| iter->idx = 0; |
| for (l = 0; l <= *pos; ) { |
| p = t_func_next(m, &l); |
| if (!p) |
| break; |
| } |
| |
| if (!p) |
| return t_mod_start(m, pos); |
| |
| return iter; |
| } |
| |
| static void t_stop(struct seq_file *m, void *p) |
| { |
| mutex_unlock(&ftrace_lock); |
| } |
| |
| void * __weak |
| arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) |
| { |
| return NULL; |
| } |
| |
| static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, |
| struct dyn_ftrace *rec) |
| { |
| void *ptr; |
| |
| ptr = arch_ftrace_trampoline_func(ops, rec); |
| if (ptr) |
| seq_printf(m, " ->%pS", ptr); |
| } |
| |
| static int t_show(struct seq_file *m, void *v) |
| { |
| struct ftrace_iterator *iter = m->private; |
| struct dyn_ftrace *rec; |
| |
| if (iter->flags & FTRACE_ITER_PROBE) |
| return t_probe_show(m, iter); |
| |
| if (iter->flags & FTRACE_ITER_MOD) |
| return t_mod_show(m, iter); |
| |
| if (iter->flags & FTRACE_ITER_PRINTALL) { |
| if (iter->flags & FTRACE_ITER_NOTRACE) |
| seq_puts(m, "#### no functions disabled ####\n"); |
| else |
| seq_puts(m, "#### all functions enabled ####\n"); |
| return 0; |
| } |
| |
| rec = iter->func; |
| |
| if (!rec) |
| return 0; |
| |
| seq_printf(m, "%ps", (void *)rec->ip); |
| if (iter->flags & FTRACE_ITER_ENABLED) { |
| struct ftrace_ops *ops; |
| |
| seq_printf(m, " (%ld)%s%s", |
| ftrace_rec_count(rec), |
| rec->flags & FTRACE_FL_REGS ? " R" : " ", |
| rec->flags & FTRACE_FL_IPMODIFY ? " I" : " "); |
| if (rec->flags & FTRACE_FL_TRAMP_EN) { |
| ops = ftrace_find_tramp_ops_any(rec); |
| if (ops) { |
| do { |
| seq_printf(m, "\ttramp: %pS (%pS)", |
| (void *)ops->trampoline, |
| (void *)ops->func); |
| add_trampoline_func(m, ops, rec); |
| ops = ftrace_find_tramp_ops_next(rec, ops); |
| } while (ops); |
| } else |
| seq_puts(m, "\ttramp: ERROR!"); |
| } else { |
| add_trampoline_func(m, NULL, rec); |
| } |
| } |
| |
| seq_putc(m, '\n'); |
| |
| return 0; |
| } |
| |
| static const struct seq_operations show_ftrace_seq_ops = { |
| .start = t_start, |
| .next = t_next, |
| .stop = t_stop, |
| .show = t_show, |
| }; |
| |
| static int |
| ftrace_avail_open(struct inode *inode, struct file *file) |
| { |
| struct ftrace_iterator *iter; |
| |
| if (unlikely(ftrace_disabled)) |
| return -ENODEV; |
| |
| iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
| if (!iter) |
| return -ENOMEM; |
| |
| iter->pg = ftrace_pages_start; |
| iter->ops = &global_ops; |
| |
| return 0; |
| } |
| |
| static int |
| ftrace_enabled_open(struct inode *inode, struct file *file) |
| { |
| struct ftrace_iterator *iter; |
| |
| iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
| if (!iter) |
| return -ENOMEM; |
| |
| iter->pg = ftrace_pages_start; |
| iter->flags = FTRACE_ITER_ENABLED; |
| iter->ops = &global_ops; |
| |
| return 0; |
| } |
| |
| /** |
| * ftrace_regex_open - initialize function tracer filter files |
| * @ops: The ftrace_ops that hold the hash filters |
| * @flag: The type of filter to process |
| * @inode: The inode, usually passed in to your open routine |
| * @file: The file, usually passed in to your open routine |
| * |
| * ftrace_regex_open() initializes the filter files for the |
| * @ops. Depending on @flag it may process the filter hash or |
| * the notrace hash of @ops. With this called from the open |
| * routine, you can use ftrace_filter_write() for the write |
| * routine if @flag has FTRACE_ITER_FILTER set, or |
| * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. |
| * tracing_lseek() should be used as the lseek routine, and |
| * release must call ftrace_regex_release(). |
| */ |
| int |
| ftrace_regex_open(struct ftrace_ops *ops, int flag, |
| struct inode *inode, struct file *file) |
| { |
| struct ftrace_iterator *iter; |
| struct ftrace_hash *hash; |
| struct list_head *mod_head; |
| struct trace_array *tr = ops->private; |
| int ret = 0; |
| |
| ftrace_ops_init(ops); |
| |
| if (unlikely(ftrace_disabled)) |
| return -ENODEV; |
| |
| iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| if (!iter) |
| return -ENOMEM; |
| |
| if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
| kfree(iter); |
| return -ENOMEM; |
| } |
| |
| iter->ops = ops; |
| iter->flags = flag; |
| iter->tr = tr; |
| |
| mutex_lock(&ops->func_hash->regex_lock); |
| |
| if (flag & FTRACE_ITER_NOTRACE) { |
| hash = ops->func_hash->notrace_hash; |
| mod_head = tr ? &tr->mod_notrace : NULL; |
| } else { |
| hash = ops->func_hash->filter_hash; |
| mod_head = tr ? &tr->mod_trace : NULL; |
| } |
| |
| iter->mod_list = mod_head; |
| |
| if (file->f_mode & FMODE_WRITE) { |
| const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
| |
| if (file->f_flags & O_TRUNC) { |
| iter->hash = alloc_ftrace_hash(size_bits); |
| clear_ftrace_mod_list(mod_head); |
| } else { |
| iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); |
| } |
| |
| if (!iter->hash) { |
| trace_parser_put(&iter->parser); |
| kfree(iter); |
| ret = -ENOMEM; |
| goto out_unlock; |
| } |
| } else |
| iter->hash = hash; |
| |
| if (file->f_mode & FMODE_READ) { |
| iter->pg = ftrace_pages_start; |
| |
| ret = seq_open(file, &show_ftrace_seq_ops); |
| if (!ret) { |
| struct seq_file *m = file->private_data; |
| m->private = iter; |
| } else { |
| /* Failed */ |
| free_ftrace_hash(iter->hash); |
| trace_parser_put(&iter->parser); |
| kfree(iter); |
| } |
| } else |
| file->private_data = iter; |
| |
| out_unlock: |
| mutex_unlock(&ops->func_hash->regex_lock); |
| |
| return ret; |
| } |
| |
| static int |
| ftrace_filter_open(struct inode *inode, struct file *file) |
| { |
| struct ftrace_ops *ops = inode->i_private; |
| |
| return ftrace_regex_open(ops, |
| FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, |
| inode, file); |
| } |
| |
| static int |
| ftrace_notrace_open(struct inode *inode, struct file *file) |
| { |
| struct ftrace_ops *ops = inode->i_private; |
| |
| return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, |
| inode, file); |
| } |
| |
| /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */ |
| struct ftrace_glob { |
| char *search; |
| unsigned len; |
| int type; |
| }; |
| |
| /* |
| * If symbols in an architecture don't correspond exactly to the user-visible |
| * name of what they represent, it is possible to define this function to |
| * perform the necessary adjustments. |
| */ |
| char * __weak arch_ftrace_match_adjust(char *str, const char *search) |
| { |
| return str; |
| } |
| |
| static int ftrace_match(char *str, struct ftrace_glob *g) |
| { |
| int matched = 0; |
| int slen; |
| |
| str = arch_ftrace_match_adjust(str, g->search); |
| |
| switch (g->type) { |
| case MATCH_FULL: |
| if (strcmp(str, g->search) == 0) |
| matched = 1; |
| break; |
| case MATCH_FRONT_ONLY: |
| if (strncmp(str, g->search, g->len) == 0) |
| matched = 1; |
| break; |
| case MATCH_MIDDLE_ONLY: |
| if (strstr(str, g->search)) |
| matched = 1; |
| break; |
| case MATCH_END_ONLY: |
| slen = strlen(str); |
| if (slen >= g->len && |
| memcmp(str + slen - g->len, g->search, g->len) == 0) |
| matched = 1; |
| break; |
| case MATCH_GLOB: |
| if (glob_match(g->search, str)) |
| matched = 1; |
| break; |
| } |
| |
| return matched; |
| } |
| |
| static int |
| enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) |
| { |
| struct ftrace_func_entry *entry; |
| int ret = 0; |
| |
| entry = ftrace_lookup_ip(hash, rec->ip); |
| if (clear_filter) { |
| /* Do nothing if it doesn't exist */ |
| if (!entry) |
| return 0; |
| |
| free_hash_entry(hash, entry); |
| } else { |
| /* Do nothing if it exists */ |
| if (entry) |
| return 0; |
| |
| ret = add_hash_entry(hash, rec->ip); |
| } |
| return ret; |
| } |
| |
| static int |
| ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, |
| struct ftrace_glob *mod_g, int exclude_mod) |
| { |
| char str[KSYM_SYMBOL_LEN]; |
| char *modname; |
| |
| kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); |
| |
| if (mod_g) { |
| int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; |
| |
| /* blank module name to match all modules */ |
| if (!mod_g->len) { |
| /* blank module globbing: modname xor exclude_mod */ |
| if (!exclude_mod != !modname) |
| goto func_match; |
| return 0; |
| } |
| |
| /* |
| * exclude_mod is set to trace everything but the given |
| * module. If it is set and the module matches, then |
| * return 0. If it is not set, and the module doesn't match |
| * also return 0. Otherwise, check the function to see if |
| * that matches. |
| */ |
| if (!mod_matches == !exclude_mod) |
| return 0; |
| func_match: |
| /* blank search means to match all funcs in the mod */ |
| if (!func_g->len) |
| return 1; |
| } |
| |
| return ftrace_match(str, func_g); |
| } |
| |
| static int |
| match_records(struct ftrace_hash *hash, char *func, int len, char *mod) |
| { |
| struct ftrace_page *pg; |
| struct dyn_ftrace *rec; |
| struct ftrace_glob func_g = { .type = MATCH_FULL }; |
| struct ftrace_glob mod_g = { .type = MATCH_FULL }; |
| struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL; |
| int exclude_mod = 0; |
| int found = 0; |
| int ret; |
| int clear_filter = 0; |
| |
| if (func) { |
| func_g.type = filter_parse_regex(func, len, &func_g.search, |
| &clear_filter); |
| func_g.len = strlen(func_g.search); |
| } |
| |
| if (mod) { |
| mod_g.type = filter_parse_regex(mod, strlen(mod), |
| &mod_g.search, &exclude_mod); |
| mod_g.len = strlen(mod_g.search); |
| } |
| |
| mutex_lock(&ftrace_lock); |
| |
| if (unlikely(ftrace_disabled)) |
| goto out_unlock; |
| |
| do_for_each_ftrace_rec(pg, rec) { |
| |
| if (rec->flags & FTRACE_FL_DISABLED) |
| continue; |
| |
| if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { |
| ret = enter_record(hash, rec, clear_filter); |
| if (ret < 0) { |
| found = ret; |
| goto out_unlock; |
| } |
| found = 1; |
| } |
| } while_for_each_ftrace_rec(); |
| out_unlock: |
| mutex_unlock(&ftrace_lock); |
| |
| return found; |
| } |
| |
| static int |
| ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
| { |
| return match_records(hash, buff, len, NULL); |
| } |
| |
| static void ftrace_ops_update_code(struct ftrace_ops *ops, |
| struct ftrace_ops_hash *old_hash) |
| { |
| struct ftrace_ops *op; |
| |
| if (!ftrace_enabled) |
| return; |
| |
| if (ops->flags & FTRACE_OPS_FL_ENABLED) { |
| ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); |
| return; |
| } |
| |
| /* |
| * If this is the shared global_ops filter, then we need to |
| * check if there is another ops that shares it, is enabled. |
| * If so, we still need to run the modify code. |
| */ |
| if (ops->func_hash != &global_ops.local_hash) |
| return; |
| |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| if (op->func_hash == &global_ops.local_hash && |
| op->flags & FTRACE_OPS_FL_ENABLED) { |
| ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); |
| /* Only need to do this once */ |
| return; |
| } |
| } while_for_each_ftrace_op(op); |
| } |
| |
| static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, |
| struct ftrace_hash **orig_hash, |
| struct ftrace_hash *hash, |
| int enable) |
| { |
| struct ftrace_ops_hash old_hash_ops; |
| struct ftrace_hash *old_hash; |
| int ret; |
| |
| old_hash = *orig_hash; |
| old_hash_ops.filter_hash = ops->func_hash->filter_hash; |
| old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; |
| ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
| if (!ret) { |
| ftrace_ops_update_code(ops, &old_hash_ops); |
| free_ftrace_hash_rcu(old_hash); |
| } |
| return ret; |
| } |
| |
| static bool module_exists(const char *module) |
| { |
| /* All modules have the symbol __this_module */ |
| const char this_mod[] = "__this_module"; |
| char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2]; |
| unsigned long val; |
| int n; |
| |
| n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod); |
| |
| if (n > sizeof(modname) - 1) |
| return false; |
| |
| val = module_kallsyms_lookup_name(modname); |
| return val != 0; |
| } |
| |
| static int cache_mod(struct trace_array *tr, |
| const char *func, char *module, int enable) |
| { |
| struct ftrace_mod_load *ftrace_mod, *n; |
| struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace; |
| int ret; |
| |
| mutex_lock(&ftrace_lock); |
| |
| /* We do not cache inverse filters */ |
| if (func[0] == '!') { |
| func++; |
| ret = -EINVAL; |
| |
| /* Look to remove this hash */ |
| list_for_each_entry_safe(ftrace_mod, n, head, list) { |
| if (strcmp(ftrace_mod->module, module) != 0) |
| continue; |
| |
| /* no func matches all */ |
| if (strcmp(func, "*") == 0 || |
| (ftrace_mod->func && |
| strcmp(ftrace_mod->func, func) == 0)) { |
| ret = 0; |
| free_ftrace_mod(ftrace_mod); |
| continue; |
| } |
| } |
| goto out; |
| } |
| |
| ret = -EINVAL; |
| /* We only care about modules that have not been loaded yet */ |
| if (module_exists(module)) |
| goto out; |
| |
| /* Save this string off, and execute it when the module is loaded */ |
| ret = ftrace_add_mod(tr, func, module, enable); |
| out: |
| mutex_unlock(&ftrace_lock); |
| |
| return ret; |
| } |
| |
| static int |
| ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, |
| int reset, int enable); |
| |
| #ifdef CONFIG_MODULES |
| static void process_mod_list(struct list_head *head, struct ftrace_ops *ops, |
| char *mod, bool enable) |
| { |
| struct ftrace_mod_load *ftrace_mod, *n; |
| struct ftrace_hash **orig_hash, *new_hash; |
| LIST_HEAD(process_mods); |
| char *func; |
| int ret; |
| |
| mutex_lock(&ops->func_hash->regex_lock); |
| |
| if (enable) |
| orig_hash = &ops->func_hash->filter_hash; |
| else |
| orig_hash = &ops->func_hash->notrace_hash; |
| |
| new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, |
| *orig_hash); |
| if (!new_hash) |
| goto out; /* warn? */ |
| |
| mutex_lock(&ftrace_lock); |
| |
| list_for_each_entry_safe(ftrace_mod, n, head, list) { |
| |
| if (strcmp(ftrace_mod->module, mod) != 0) |
| continue; |
| |
| if (ftrace_mod->func) |
| func = kstrdup(ftrace_mod->func, GFP_KERNEL); |
| else |
| func = kstrdup("*", GFP_KERNEL); |
| |
| if (!func) /* warn? */ |
| continue; |
| |
| list_del(&ftrace_mod->list); |
| list_add(&ftrace_mod->list, &process_mods); |
| |
| /* Use the newly allocated func, as it may be "*" */ |
| kfree(ftrace_mod->func); |
| ftrace_mod->func = func; |
| } |
| |
| mutex_unlock(&ftrace_lock); |
| |
| list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) { |
| |
| func = ftrace_mod->func; |
| |
| /* Grabs ftrace_lock, which is why we have this extra step */ |
| match_records(new_hash, func, strlen(func), mod); |
| free_ftrace_mod(ftrace_mod); |
| } |
| |
| if (enable && list_empty(head)) |
| new_hash->flags &= ~FTRACE_HASH_FL_MOD; |
| |
| mutex_lock(&ftrace_lock); |
| |
| ret = ftrace_hash_move_and_update_ops(ops, orig_hash, |
| new_hash, enable); |
| mutex_unlock(&ftrace_lock); |
| |
| out: |
| mutex_unlock(&ops->func_hash->regex_lock); |
| |
| free_ftrace_hash(new_hash); |
| } |
| |
| static void process_cached_mods(const char *mod_name) |
| { |
| struct trace_array *tr; |
| char *mod; |
| |
| mod = kstrdup(mod_name, GFP_KERNEL); |
| if (!mod) |
| return; |
| |
| mutex_lock(&trace_types_lock); |
| list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
| if (!list_empty(&tr->mod_trace)) |
| process_mod_list(&tr->mod_trace, tr->ops, mod, true); |
| if (!list_empty(&tr->mod_notrace)) |
| process_mod_list(&tr->mod_notrace, tr->ops, mod, false); |
| } |
| mutex_unlock(&trace_types_lock); |
| |
| kfree(mod); |
| } |
| #endif |
| |
| /* |
| * We register the module command as a template to show others how |
| * to register the a command as well. |
| */ |
| |
| static int |
| ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash, |
| char *func_orig, char *cmd, char *module, int enable) |
| { |
| char *func; |
| int ret; |
| |
| /* match_records() modifies func, and we need the original */ |
| func = kstrdup(func_orig, GFP_KERNEL); |
| if (!func) |
| return -ENOMEM; |
| |
| /* |
| * cmd == 'mod' because we only registered this func |
| * for the 'mod' ftrace_func_command. |
| * But if you register one func with multiple commands, |
| * you can tell which command was used by the cmd |
| * parameter. |
| */ |
| ret = match_records(hash, func, strlen(func), module); |
| kfree(func); |
| |
| if (!ret) |
| return cache_mod(tr, func_orig, module, enable); |
| if (ret < 0) |
| return ret; |
| return 0; |
| } |
| |
| static struct ftrace_func_command ftrace_mod_cmd = { |
| .name = "mod", |
| .func = ftrace_mod_callback, |
| }; |
| |
| static int __init ftrace_mod_cmd_init(void) |
| { |
| return register_ftrace_command(&ftrace_mod_cmd); |
| } |
| core_initcall(ftrace_mod_cmd_init); |
| |
| static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
| struct ftrace_ops *op, struct pt_regs *pt_regs) |
| { |
| struct ftrace_probe_ops *probe_ops; |
| struct ftrace_func_probe *probe; |
| |
| probe = container_of(op, struct ftrace_func_probe, ops); |
| probe_ops = probe->probe_ops; |
| |
| /* |
| * Disable preemption for these calls to prevent a RCU grace |
| * period. This syncs the hash iteration and freeing of items |
| * on the hash. rcu_read_lock is too dangerous here. |
| */ |
| preempt_disable_notrace(); |
| probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data); |
| preempt_enable_notrace(); |
| } |
| |
| struct ftrace_func_map { |
| struct ftrace_func_entry entry; |
| void *data; |
| }; |
| |
| struct ftrace_func_mapper { |
| struct ftrace_hash hash; |
| }; |
| |
| /** |
| * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper |
| * |
| * Returns a ftrace_func_mapper descriptor that can be used to map ips to data. |
| */ |
| struct ftrace_func_mapper *allocate_ftrace_func_mapper(void) |
| { |
| struct ftrace_hash *hash; |
| |
| /* |
| * The mapper is simply a ftrace_hash, but since the entries |
| * in the hash are not ftrace_func_entry type, we define it |
| * as a separate structure. |
| */ |
| hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
| return (struct ftrace_func_mapper *)hash; |
| } |
| |
| /** |
| * ftrace_func_mapper_find_ip - Find some data mapped to an ip |
| * @mapper: The mapper that has the ip maps |
| * @ip: the instruction pointer to find the data for |
| * |
| * Returns the data mapped to @ip if found otherwise NULL. The return |
| * is actually the address of the mapper data pointer. The address is |
| * returned for use cases where the data is no bigger than a long, and |
| * the user can use the data pointer as its data instead of having to |
| * allocate more memory for the reference. |
| */ |
| void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper, |
| unsigned long ip) |
| { |
| struct ftrace_func_entry *entry; |
| struct ftrace_func_map *map; |
| |
| entry = ftrace_lookup_ip(&mapper->hash, ip); |
| if (!entry) |
| return NULL; |
| |
| map = (struct ftrace_func_map *)entry; |
| return &map->data; |
| } |
| |
| /** |
| * ftrace_func_mapper_add_ip - Map some data to an ip |
| * @mapper: The mapper that has the ip maps |
| * @ip: The instruction pointer address to map @data to |
| * @data: The data to map to @ip |
| * |
| * Returns 0 on succes otherwise an error. |
| */ |
| int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper, |
| unsigned long ip, void *data) |
| { |
| struct ftrace_func_entry *entry; |
| struct ftrace_func_map *map; |
| |
| entry = ftrace_lookup_ip(&mapper->hash, ip); |
| if (entry) |
| return -EBUSY; |
| |
| map = kmalloc(sizeof(*map), GFP_KERNEL); |
| if (!map) |
| return -ENOMEM; |
| |
| map->entry.ip = ip; |
| map->data = data; |
| |
| __add_hash_entry(&mapper->hash, &map->entry); |
| |
| return 0; |
| } |
| |
| /** |
| * ftrace_func_mapper_remove_ip - Remove an ip from the mapping |
| * @mapper: The mapper that has the ip maps |
| * @ip: The instruction pointer address to remove the data from |
| * |
| * Returns the data if it is found, otherwise NULL. |
| * Note, if the data pointer is used as the data itself, (see |
| * ftrace_func_mapper_find_ip(), then the return value may be meaningless, |
| * if the data pointer was set to zero. |
| */ |
| void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper, |
| unsigned long ip) |
| { |
| struct ftrace_func_entry *entry; |
| struct ftrace_func_map *map; |
| void *data; |
| |
| entry = ftrace_lookup_ip(&mapper->hash, ip); |
| if (!entry) |
| return NULL; |
| |
| map = (struct ftrace_func_map *)entry; |
| data = map->data; |
| |
| remove_hash_entry(&mapper->hash, entry); |
| kfree(entry); |
| |
| return data; |
| } |
| |
| /** |
| * free_ftrace_func_mapper - free a mapping of ips and data |
| * @mapper: The mapper that has the ip maps |
| * @free_func: A function to be called on each data item. |
| * |
| * This is used to free the function mapper. The @free_func is optional |
| * and can be used if the data needs to be freed as well. |
| */ |
| void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, |
| ftrace_mapper_func free_func) |
| { |
| struct ftrace_func_entry *entry; |
| struct ftrace_func_map *map; |
| struct hlist_head *hhd; |
| int size = 1 << mapper->hash.size_bits; |
| int i; |
| |
| if (free_func && mapper->hash.count) { |
| for (i = 0; i < size; i++) { |
| hhd = &mapper->hash.buckets[i]; |
| hlist_for_each_entry(entry, hhd, hlist) { |
| map = (struct ftrace_func_map *)entry; |
| free_func(map); |
| } |
| } |
| } |
| free_ftrace_hash(&mapper->hash); |
| } |
| |
| static void release_probe(struct ftrace_func_probe *probe) |
| { |
| struct ftrace_probe_ops *probe_ops; |
| |
| mutex_lock(&ftrace_lock); |
| |
| WARN_ON(probe->ref <= 0); |
| |
| /* Subtract the ref that was used to protect this instance */ |
| probe->ref--; |
| |
| if (!probe->ref) { |
| probe_ops = probe->probe_ops; |
| /* |
| * Sending zero as ip tells probe_ops to free |
| * the probe->data itself |
| */ |
| if (probe_ops->free) |
| probe_ops->free(probe_ops, probe->tr, 0, probe->data); |
| list_del(&probe->list); |
| kfree(probe); |
| } |
| mutex_unlock(&ftrace_lock); |
| } |
| |
| static void acquire_probe_locked(struct ftrace_func_probe *probe) |
| { |
| /* |
| * Add one ref to keep it from being freed when releasing the |
| * ftrace_lock mutex. |
| */ |
| probe->ref++; |
| } |
| |
| int |
| register_ftrace_function_probe(char *glob, struct trace_array *tr, |
| struct ftrace_probe_ops *probe_ops, |
| void *data) |
| { |
| struct ftrace_func_entry *entry; |
| struct ftrace_func_probe *probe; |
| struct ftrace_hash **orig_hash; |
| struct ftrace_hash *old_hash; |
| struct ftrace_hash *hash; |
| int count = 0; |
| int size; |
| int ret; |
| int i; |
| |
| if (WARN_ON(!tr)) |
| return -EINVAL; |
| |
| /* We do not support '!' for function probes */ |
| if (WARN_ON(glob[0] == '!')) |
| return -EINVAL; |
| |
| |
| mutex_lock(&ftrace_lock); |
| /* Check if the probe_ops is already registered */ |
| list_for_each_entry(probe, &tr->func_probes, list) { |
| if (probe->probe_ops == probe_ops) |
| break; |
| } |
| if (&probe->list == &tr->func_probes) { |
| probe = kzalloc(sizeof(*probe), GFP_KERNEL); |
| if (!probe) { |
| mutex_unlock(&ftrace_lock); |
| return -ENOMEM; |
| } |
| probe->probe_ops = probe_ops; |
| probe->ops.func = function_trace_probe_call; |
| probe->tr = tr; |
| ftrace_ops_init(&probe->ops); |
| list_add(&probe->list, &tr->func_probes); |
| } |
| |
| acquire_probe_locked(probe); |
| |
| mutex_unlock(&ftrace_lock); |
| |
| mutex_lock(&probe->ops.func_hash->regex_lock); |
| |
| orig_hash = &probe->ops.func_hash->filter_hash; |
| old_hash = *orig_hash; |
| hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
| |
| ret = ftrace_match_records(hash, glob, strlen(glob)); |
| |
| /* Nothing found? */ |
| if (!ret) |
| ret = -EINVAL; |
| |
| if (ret < 0) |
| goto out; |
| |
| size = 1 << hash->size_bits; |
| for (i = 0; i < size; i++) { |
| hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
| if (ftrace_lookup_ip(old_hash, entry->ip)) |
| continue; |
| /* |
| * The caller might want to do something special |
| * for each function we find. We call the callback |
| * to give the caller an opportunity to do so. |
| */ |
| if (probe_ops->init) { |
| ret = probe_ops->init(probe_ops, tr, |
| entry->ip, data, |
| &probe->data); |
| if (ret < 0) { |
| if (probe_ops->free && count) |
| probe_ops->free(probe_ops, tr, |
| 0, probe->data); |
| probe->data = NULL; |
| goto out; |
| } |
| } |
| count++; |
| } |
| } |
| |
| mutex_lock(&ftrace_lock); |
| |
| if (!count) { |
| /* Nothing was added? */ |
| ret = -EINVAL; |
| goto out_unlock; |
| } |
| |
| ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, |
| hash, 1); |
| if (ret < 0) |
| goto err_unlock; |
| |
| /* One ref for each new function traced */ |
| probe->ref += count; |
| |
| if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED)) |
| ret = ftrace_startup(&probe->ops, 0); |
| |
| out_unlock: |
| mutex_unlock(&ftrace_lock); |
| |
| if (!ret) |
| ret = count; |
| out: |
| mutex_unlock(&probe->ops.func_hash->regex_lock); |
| free_ftrace_hash(hash); |
| |
| release_probe(probe); |
| |
| return ret; |
| |
| err_unlock: |
| if (!probe_ops->free || !count) |
| goto out_unlock; |
| |
| /* Failed to do the move, need to call the free functions */ |
| for (i = 0; i < size; i++) { |
| hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
| if (ftrace_lookup_ip(old_hash, entry->ip)) |
| continue; |
| probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
| } |
| } |
| goto out_unlock; |
| } |
| |
| int |
| unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, |
| struct ftrace_probe_ops *probe_ops) |
| { |
| struct ftrace_ops_hash old_hash_ops; |
| struct ftrace_func_entry *entry; |
| struct ftrace_func_probe *probe; |
| struct ftrace_glob func_g; |
| struct ftrace_hash **orig_hash; |
| struct ftrace_hash *old_hash; |
| struct ftrace_hash *hash = NULL; |
| struct hlist_node *tmp; |
| struct hlist_head hhd; |
| char str[KSYM_SYMBOL_LEN]; |
| int count = 0; |
| int i, ret = -ENODEV; |
| int size; |
| |
| if (!glob || !strlen(glob) || !strcmp(glob, "*")) |
| func_g.search = NULL; |
| else { |
| int not; |
| |
| func_g.type = filter_parse_regex(glob, strlen(glob), |
| &func_g.search, ¬); |
| func_g.len = strlen(func_g.search); |
| |
| /* we do not support '!' for function probes */ |
| if (WARN_ON(not)) |
| return -EINVAL; |
| } |
| |
| mutex_lock(&ftrace_lock); |
| /* Check if the probe_ops is already registered */ |
| list_for_each_entry(probe, &tr->func_probes, list) { |
| if (probe->probe_ops == probe_ops) |
| break; |
| } |
| if (&probe->list == &tr->func_probes) |
| goto err_unlock_ftrace; |
| |
| ret = -EINVAL; |
| if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED)) |
| goto err_unlock_ftrace; |
| |
| acquire_probe_locked(probe); |
| |
| mutex_unlock(&ftrace_lock); |
| |
| mutex_lock(&probe->ops.func_hash->regex_lock); |
| |
| orig_hash = &probe->ops.func_hash->filter_hash; |
| old_hash = *orig_hash; |
| |
| if (ftrace_hash_empty(old_hash)) |
| goto out_unlock; |
| |
| old_hash_ops.filter_hash = old_hash; |
| /* Probes only have filters */ |
| old_hash_ops.notrace_hash = NULL; |
| |
| ret = -ENOMEM; |
| hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
| if (!hash) |
| goto out_unlock; |
| |
| INIT_HLIST_HEAD(&hhd); |
| |
| size = 1 << hash->size_bits; |
| for (i = 0; i < size; i++) { |
| hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) { |
| |
| if (func_g.search) { |
| kallsyms_lookup(entry->ip, NULL, NULL, |
| NULL, str); |
| if (!ftrace_match(str, &func_g)) |
| continue; |
| } |
| count++; |
| remove_hash_entry(hash, entry); |
| hlist_add_head(&entry->hlist, &hhd); |
| } |
| } |
| |
| /* Nothing found? */ |
| if (!count) { |
| ret = -EINVAL; |
| goto out_unlock; |
| } |
| |
| mutex_lock(&ftrace_lock); |
| |
| WARN_ON(probe->ref < count); |
| |
| probe->ref -= count; |
| |
| if (ftrace_hash_empty(hash)) |
| ftrace_shutdown(&probe->ops, 0); |
| |
| ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, |
| hash, 1); |
| |
| /* still need to update the function call sites */ |
| if (ftrace_enabled && !ftrace_hash_empty(hash)) |
| ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS, |
| &old_hash_ops); |
| synchronize_sched(); |
| |
| hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) { |
| hlist_del(&entry->hlist); |
| if (probe_ops->free) |
| probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
| kfree(entry); |
| } |
| mutex_unlock(&ftrace_lock); |
| |
| out_unlock: |
| mutex_unlock(&probe->ops.func_hash->regex_lock); |
| free_ftrace_hash(hash); |
| |
| release_probe(probe); |
| |
| return ret; |
| |
| err_unlock_ftrace: |
| mutex_unlock(&ftrace_lock); |
| return ret; |
| } |
| |
| void clear_ftrace_function_probes(struct trace_array *tr) |
| { |
| struct ftrace_func_probe *probe, *n; |
| |
| list_for_each_entry_safe(probe, n, &tr->func_probes, list) |
| unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops); |
| } |
| |
| static LIST_HEAD(ftrace_commands); |
| static DEFINE_MUTEX(ftrace_cmd_mutex); |
| |
| /* |
| * Currently we only register ftrace commands from __init, so mark this |
| * __init too. |
| */ |
| __init int register_ftrace_command(struct ftrace_func_command *cmd) |
| { |
| struct ftrace_func_command *p; |
| int ret = 0; |
| |
| mutex_lock(&ftrace_cmd_mutex); |
| list_for_each_entry(p, &ftrace_commands, list) { |
| if (strcmp(cmd->name, p->name) == 0) { |
| ret = -EBUSY; |
| goto out_unlock; |
| } |
| } |
| list_add(&cmd->list, &ftrace_commands); |
| out_unlock: |
| mutex_unlock(&ftrace_cmd_mutex); |
| |
| return ret; |
| } |
| |
| /* |
| * Currently we only unregister ftrace commands from __init, so mark |
| * this __init too. |
| */ |
| __init int unregister_ftrace_command(struct ftrace_func_command *cmd) |
| { |
| struct ftrace_func_command *p, *n; |
| int ret = -ENODEV; |
| |
| mutex_lock(&ftrace_cmd_mutex); |
| list_for_each_entry_safe(p, n, &ftrace_commands, list) { |
| if (strcmp(cmd->name, p->name) == 0) { |
| ret = 0; |
| list_del_init(&p->list); |
| goto out_unlock; |
| } |
| } |
| out_unlock: |
| mutex_unlock(&ftrace_cmd_mutex); |
| |
| return ret; |
| } |
| |
| static int ftrace_process_regex(struct ftrace_iterator *iter, |
| char *buff, int len, int enable) |
| { |
| struct ftrace_hash *hash = iter->hash; |
| struct trace_array *tr = iter->ops->private; |
| char *func, *command, *next = buff; |
| struct ftrace_func_command *p; |
| int ret = -EINVAL; |
| |
| func = strsep(&next, ":"); |
| |
| if (!next) { |
| ret = ftrace_match_records(hash, func, len); |
| if (!ret) |
| ret = -EINVAL; |
| if (ret < 0) |
| return ret; |
| return 0; |
| } |
| |
| /* command found */ |
| |
| command = strsep(&next, ":"); |
| |
| mutex_lock(&ftrace_cmd_mutex); |
| list_for_each_entry(p, &ftrace_commands, list) { |
| if (strcmp(p->name, command) == 0) { |
| ret = p->func(tr, hash, func, command, next, enable); |
| goto out_unlock; |
| } |
| } |
| out_unlock: |
| mutex_unlock(&ftrace_cmd_mutex); |
| |
| return ret; |
| } |
| |
| static ssize_t |
| ftrace_regex_write(struct file *file, const char __user *ubuf, |
| size_t cnt, loff_t *ppos, int enable) |
| { |
| struct ftrace_iterator *iter; |
| struct trace_parser *parser; |
| ssize_t ret, read; |
| |
| if (!cnt) |
| return 0; |
| |
| if (file->f_mode & FMODE_READ) { |
| struct seq_file *m = file->private_data; |
| iter = m->private; |
| } else |
| iter = file->private_data; |
| |
| if (unlikely(ftrace_disabled)) |
| return -ENODEV; |
| |
| /* iter->hash is a local copy, so we don't need regex_lock */ |
| |
| parser = &iter->parser; |
| read = trace_get_user(parser, ubuf, cnt, ppos); |
| |
| if (read >= 0 && trace_parser_loaded(parser) && |
| !trace_parser_cont(parser)) { |
| ret = ftrace_process_regex(iter, parser->buffer, |
| parser->idx, enable); |
| trace_parser_clear(parser); |
| if (ret < 0) |
| goto out; |
| } |
| |
| ret = read; |
| out: |
| return ret; |
| } |
| |
| ssize_t |
| ftrace_filter_write(struct file *file, const char __user *ubuf, |
| size_t cnt, loff_t *ppos) |
| { |
| return ftrace_regex_write(file, ubuf, cnt, ppos, 1); |
| } |
| |
| ssize_t |
| ftrace_notrace_write(struct file *file, const char __user *ubuf, |
| size_t cnt, loff_t *ppos) |
| { |
| return ftrace_regex_write(file, ubuf, cnt, ppos, 0); |
| } |
| |
| static int |
| ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
| { |
| struct ftrace_func_entry *entry; |
| |
| if (!ftrace_location(ip)) |
| return -EINVAL; |
| |
| if (remove) { |
| entry = ftrace_lookup_ip(hash, ip); |
| if (!entry) |
| return -ENOENT; |
| free_hash_entry(hash, entry); |
| return 0; |
| } |
| |
| return add_hash_entry(hash, ip); |
| } |
| |
| static int |
| ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, |
| unsigned long ip, int remove, int reset, int enable) |
| { |
| struct ftrace_hash **orig_hash; |
| struct ftrace_hash *hash; |
| int ret; |
| |
| if (unlikely(ftrace_disabled)) |
| return -ENODEV; |
| |
| mutex_lock(&ops->func_hash->regex_lock); |
| |
| if (enable) |
| orig_hash = &ops->func_hash->filter_hash; |
| else |
| orig_hash = &ops->func_hash->notrace_hash; |
| |
| if (reset) |
| hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
| else |
| hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); |
| |
| if (!hash) { |
| ret = -ENOMEM; |
| goto out_regex_unlock; |
| } |
| |
| if (buf && !ftrace_match_records(hash, buf, len)) { |
| ret = -EINVAL; |
| goto out_regex_unlock; |
| } |
| if (ip) { |
| ret = ftrace_match_addr(hash, ip, remove); |
| if (ret < 0) |
| goto out_regex_unlock; |
| } |
| |
| mutex_lock(&ftrace_lock); |
| ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable); |
| mutex_unlock(&ftrace_lock); |
| |
| out_regex_unlock: |
| mutex_unlock(&ops->func_hash->regex_lock); |
| |
| free_ftrace_hash(hash); |
| return ret; |
| } |
| |
| static int |
| ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, |
| int reset, int enable) |
| { |
| return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); |
| } |
| |
| /** |
| * ftrace_set_filter_ip - set a function to filter on in ftrace by address |
| * @ops - the ops to set the filter with |
| * @ip - the address to add to or remove from the filter. |
| * @remove - non zero to remove the ip from the filter |
| * @reset - non zero to reset all filters before applying this filter. |
| * |
| * Filters denote which functions should be enabled when tracing is enabled |
| * If @ip is NULL, it failes to update filter. |
| */ |
| int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, |
| int remove, int reset) |
| { |
| ftrace_ops_init(ops); |
| return ftrace_set_addr(ops, ip, remove, reset, 1); |
| } |
| EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); |
| |
| /** |
| * ftrace_ops_set_global_filter - setup ops to use global filters |
| * @ops - the ops which will use the global filters |
| * |
| * ftrace users who need global function trace filtering should call this. |
| * It can set the global filter only if ops were not initialized before. |
| */ |
| void ftrace_ops_set_global_filter(struct ftrace_ops *ops) |
| { |
| if (ops->flags & FTRACE_OPS_FL_INITIALIZED) |
| return; |
| |
| ftrace_ops_init(ops); |
| ops->func_hash = &global_ops.local_hash; |
| } |
| EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter); |
| |
| static int |
| ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, |
| int reset, int enable) |
| { |
| return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); |
| } |
| |
| /** |
| * ftrace_set_filter - set a function to filter on in ftrace |
| * @ops - the ops to set the filter with |
| * @buf - the string that holds the function filter text. |
| * @len - the length of the string. |
| * @reset - non zero to reset all filters before applying this filter. |
| * |
| * Filters denote which functions should be enabled when tracing is enabled. |
| * If @buf is NULL and reset is set, all functions will be enabled for tracing. |
| */ |
| int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
| int len, int reset) |
| { |
| ftrace_ops_init(ops); |
| return ftrace_set_regex(ops, buf, len, reset, 1); |
| } |
| EXPORT_SYMBOL_GPL(ftrace_set_filter); |
| |
| /** |
| * ftrace_set_notrace - set a function to not trace in ftrace |
| * @ops - the ops to set the notrace filter with |
| * @buf - the string that holds the function notrace text. |
| * @len - the length of the string. |
| * @reset - non zero to reset all filters before applying this filter. |
| * |
| * Notrace Filters denote which functions should not be enabled when tracing |
| * is enabled. If @buf is NULL and reset is set, all functions will be enabled |
| * for tracing. |
| */ |
| int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
| int len, int reset) |
| { |
| ftrace_ops_init(ops); |
| return ftrace_set_regex(ops, buf, len, reset, 0); |
| } |
| EXPORT_SYMBOL_GPL(ftrace_set_notrace); |
| /** |
| * ftrace_set_global_filter - set a function to filter on with global tracers |
| * @buf - the string that holds the function filter text. |
| * @len - the length of the string. |
| * @reset - non zero to reset all filters before applying this filter. |
| * |
| * Filters denote which functions should be enabled when tracing is enabled. |
| * If @buf is NULL and reset is set, all functions will be enabled for tracing. |
| */ |
| void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
| { |
| ftrace_set_regex(&global_ops, buf, len, reset, 1); |
| } |
| EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
| |
| /** |
| * ftrace_set_global_notrace - set a function to not trace with global tracers |
| * @buf - the string that holds the function notrace text. |
| * @len - the length of the string. |
| * @reset - non zero to reset all filters before applying this filter. |
| * |
| * Notrace Filters denote which functions should not be enabled when tracing |
| * is enabled. If @buf is NULL and reset is set, all functions will be enabled |
| * for tracing. |
| */ |
| void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
| { |
| ftrace_set_regex(&global_ops, buf, len, reset, 0); |
| } |
| EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
| |
| /* |
| * command line interface to allow users to set filters on boot up. |
| */ |
| #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE |
| static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
| static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; |
| |
| /* Used by function selftest to not test if filter is set */ |
| bool ftrace_filter_param __initdata; |
| |
| static int __init set_ftrace_notrace(char *str) |
| { |
| ftrace_filter_param = true; |
| strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
| return 1; |
| } |
| __setup("ftrace_notrace=", set_ftrace_notrace); |
| |
| static int __init set_ftrace_filter(char *str) |
| { |
| ftrace_filter_param = true; |
| strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
| return 1; |
| } |
| __setup("ftrace_filter=", set_ftrace_filter); |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
| static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
| static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer); |
| |
| static int __init set_graph_function(char *str) |
| { |
| strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
| return 1; |
| } |
| __setup("ftrace_graph_filter=", set_graph_function); |
| |
| static int __init set_graph_notrace_function(char *str) |
| { |
| strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); |
| return 1; |
| } |
| __setup("ftrace_graph_notrace=", set_graph_notrace_function); |
| |
| static int __init set_graph_max_depth_function(char *str) |
| { |
| if (!str) |
| return 0; |
| fgraph_max_depth = simple_strtoul(str, NULL, 0); |
| return 1; |
| } |
| __setup("ftrace_graph_max_depth=", set_graph_max_depth_function); |
| |
| static void __init set_ftrace_early_graph(char *buf, int enable) |
| { |
| int ret; |
| char *func; |
| struct ftrace_hash *hash; |
| |
| hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
| if (WARN_ON(!hash)) |
| return; |
| |
| while (buf) { |
| func = strsep(&buf, ","); |
| /* we allow only one expression at a time */ |
| ret = ftrace_graph_set_hash(hash, func); |
| if (ret) |
| printk(KERN_DEBUG "ftrace: function %s not " |
| "traceable\n", func); |
| } |
| |
| if (enable) |
| ftrace_graph_hash = hash; |
| else |
| ftrace_graph_notrace_hash = hash; |
| } |
| #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
| |
| void __init |
| ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) |
| { |
| char *func; |
| |
| ftrace_ops_init(ops); |
| |
| while (buf) { |
| func = strsep(&buf, ","); |
| ftrace_set_regex(ops, func, strlen(func), 0, enable); |
| } |
| } |
| |
| static void __init set_ftrace_early_filters(void) |
| { |
| if (ftrace_filter_buf[0]) |
| ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
| if (ftrace_notrace_buf[0]) |
| ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| if (ftrace_graph_buf[0]) |
| set_ftrace_early_graph(ftrace_graph_buf, 1); |
| if (ftrace_graph_notrace_buf[0]) |
| set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); |
| #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
| } |
| |
| int ftrace_regex_release(struct inode *inode, struct file *file) |
| { |
| struct seq_file *m = (struct seq_file *)file->private_data; |
| struct ftrace_iterator *iter; |
| struct ftrace_hash **orig_hash; |
| struct trace_parser *parser; |
| int filter_hash; |
| int ret; |
| |
| if (file->f_mode & FMODE_READ) { |
| iter = m->private; |
| seq_release(inode, file); |
| } else |
| iter = file->private_data; |
| |
| parser = &iter->parser; |
| if (trace_parser_loaded(parser)) { |
| ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
| } |
| |
| trace_parser_put(parser); |
| |
| mutex_lock(&iter->ops->func_hash->regex_lock); |
| |
| if (file->f_mode & FMODE_WRITE) { |
| filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
| |
| if (filter_hash) { |
| orig_hash = &iter->ops->func_hash->filter_hash; |
| if (iter->tr && !list_empty(&iter->tr->mod_trace)) |
| iter->hash->flags |= FTRACE_HASH_FL_MOD; |
| } else |
| orig_hash = &iter->ops->func_hash->notrace_hash; |
| |
| mutex_lock(&ftrace_lock); |
| ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash, |
| iter->hash, filter_hash); |
| mutex_unlock(&ftrace_lock); |
| } else { |
| /* For read only, the hash is the ops hash */ |
| iter->hash = NULL; |
| } |
| |
| mutex_unlock(&iter->ops->func_hash->regex_lock); |
| free_ftrace_hash(iter->hash); |
| kfree(iter); |
| |
| return 0; |
| } |
| |
| static const struct file_operations ftrace_avail_fops = { |
| .open = ftrace_avail_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_private, |
| }; |
| |
| static const struct file_operations ftrace_enabled_fops = { |
| .open = ftrace_enabled_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_private, |
| }; |
| |
| static const struct file_operations ftrace_filter_fops = { |
| .open = ftrace_filter_open, |
| .read = seq_read, |
| .write = ftrace_filter_write, |
| .llseek = tracing_lseek, |
| .release = ftrace_regex_release, |
| }; |
| |
| static const struct file_operations ftrace_notrace_fops = { |
| .open = ftrace_notrace_open, |
| .read = seq_read, |
| .write = ftrace_notrace_write, |
| .llseek = tracing_lseek, |
| .release = ftrace_regex_release, |
| }; |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| |
| static DEFINE_MUTEX(graph_lock); |
| |
| struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH; |
| struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH; |
| |
| enum graph_filter_type { |
| GRAPH_FILTER_NOTRACE = 0, |
| GRAPH_FILTER_FUNCTION, |
| }; |
| |
| #define FTRACE_GRAPH_EMPTY ((void *)1) |
| |
| struct ftrace_graph_data { |
| struct ftrace_hash *hash; |
| struct ftrace_func_entry *entry; |
| int idx; /* for hash table iteration */ |
| enum graph_filter_type type; |
| struct ftrace_hash *new_hash; |
| const struct seq_operations *seq_ops; |
| struct trace_parser parser; |
| }; |
| |
| static void * |
| __g_next(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_graph_data *fgd = m->private; |
| struct ftrace_func_entry *entry = fgd->entry; |
| struct hlist_head *head; |
| int i, idx = fgd->idx; |
| |
| if (*pos >= fgd->hash->count) |
| return NULL; |
| |
| if (entry) { |
| hlist_for_each_entry_continue(entry, hlist) { |
| fgd->entry = entry; |
| return entry; |
| } |
| |
| idx++; |
| } |
| |
| for (i = idx; i < 1 << fgd->hash->size_bits; i++) { |
| head = &fgd->hash->buckets[i]; |
| hlist_for_each_entry(entry, head, hlist) { |
| fgd->entry = entry; |
| fgd->idx = i; |
| return entry; |
| } |
| } |
| return NULL; |
| } |
| |
| static void * |
| g_next(struct seq_file *m, void *v, loff_t *pos) |
| { |
| (*pos)++; |
| return __g_next(m, pos); |
| } |
| |
| static void *g_start(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_graph_data *fgd = m->private; |
| |
| mutex_lock(&graph_lock); |
| |
| if (fgd->type == GRAPH_FILTER_FUNCTION) |
| fgd->hash = rcu_dereference_protected(ftrace_graph_hash, |
| lockdep_is_held(&graph_lock)); |
| else |
| fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
| lockdep_is_held(&graph_lock)); |
| |
| /* Nothing, tell g_show to print all functions are enabled */ |
| if (ftrace_hash_empty(fgd->hash) && !*pos) |
| return FTRACE_GRAPH_EMPTY; |
| |
| fgd->idx = 0; |
| fgd->entry = NULL; |
| return __g_next(m, pos); |
| } |
| |
| static void g_stop(struct seq_file *m, void *p) |
| { |
| mutex_unlock(&graph_lock); |
| } |
| |
| static int g_show(struct seq_file *m, void *v) |
| { |
| struct ftrace_func_entry *entry = v; |
| |
| if (!entry) |
| return 0; |
| |
| if (entry == FTRACE_GRAPH_EMPTY) { |
| struct ftrace_graph_data *fgd = m->private; |
| |
| if (fgd->type == GRAPH_FILTER_FUNCTION) |
| seq_puts(m, "#### all functions enabled ####\n"); |
| else |
| seq_puts(m, "#### no functions disabled ####\n"); |
| return 0; |
| } |
| |
| seq_printf(m, "%ps\n", (void *)entry->ip); |
| |
| return 0; |
| } |
| |
| static const struct seq_operations ftrace_graph_seq_ops = { |
| .start = g_start, |
| .next = g_next, |
| .stop = g_stop, |
| .show = g_show, |
| }; |
| |
| static int |
| __ftrace_graph_open(struct inode *inode, struct file *file, |
| struct ftrace_graph_data *fgd) |
| { |
| int ret = 0; |
| struct ftrace_hash *new_hash = NULL; |
| |
| if (file->f_mode & FMODE_WRITE) { |
| const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
| |
| if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX)) |
| return -ENOMEM; |
| |
| if (file->f_flags & O_TRUNC) |
| new_hash = alloc_ftrace_hash(size_bits); |
| else |
| new_hash = alloc_and_copy_ftrace_hash(size_bits, |
| fgd->hash); |
| if (!new_hash) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| } |
| |
| if (file->f_mode & FMODE_READ) { |
| ret = seq_open(file, &ftrace_graph_seq_ops); |
| if (!ret) { |
| struct seq_file *m = file->private_data; |
| m->private = fgd; |
| } else { |
| /* Failed */ |
| free_ftrace_hash(new_hash); |
| new_hash = NULL; |
| } |
| } else |
| file->private_data = fgd; |
| |
| out: |
| if (ret < 0 && file->f_mode & FMODE_WRITE) |
| trace_parser_put(&fgd->parser); |
| |
| fgd->new_hash = new_hash; |
| |
| /* |
| * All uses of fgd->hash must be taken with the graph_lock |
| * held. The graph_lock is going to be released, so force |
| * fgd->hash to be reinitialized when it is taken again. |
| */ |
| fgd->hash = NULL; |
| |
| return ret; |
| } |
| |
| static int |
| ftrace_graph_open(struct inode *inode, struct file *file) |
| { |
| struct ftrace_graph_data *fgd; |
| int ret; |
| |
| if (unlikely(ftrace_disabled)) |
| return -ENODEV; |
| |
| fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); |
| if (fgd == NULL) |
| return -ENOMEM; |
| |
| mutex_lock(&graph_lock); |
| |
| fgd->hash = rcu_dereference_protected(ftrace_graph_hash, |
| lockdep_is_held(&graph_lock)); |
| fgd->type = GRAPH_FILTER_FUNCTION; |
| fgd->seq_ops = &ftrace_graph_seq_ops; |
| |
| ret = __ftrace_graph_open(inode, file, fgd); |
| if (ret < 0) |
| kfree(fgd); |
| |
| mutex_unlock(&graph_lock); |
| return ret; |
| } |
| |
| static int |
| ftrace_graph_notrace_open(struct inode *inode, struct file *file) |
| { |
| struct ftrace_graph_data *fgd; |
| int ret; |
| |
| if (unlikely(ftrace_disabled)) |
| return -ENODEV; |
| |
| fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); |
| if (fgd == NULL) |
| return -ENOMEM; |
| |
| mutex_lock(&graph_lock); |
| |
| fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
| lockdep_is_held(&graph_lock)); |
| fgd->type = GRAPH_FILTER_NOTRACE; |
| fgd->seq_ops = &ftrace_graph_seq_ops; |
| |
| ret = __ftrace_graph_open(inode, file, fgd); |
| if (ret < 0) |
| kfree(fgd); |
| |
| mutex_unlock(&graph_lock); |
| return ret; |
| } |
| |
| static int |
| ftrace_graph_release(struct inode *inode, struct file *file) |
| { |
| struct ftrace_graph_data *fgd; |
| struct ftrace_hash *old_hash, *new_hash; |
| struct trace_parser *parser; |
| int ret = 0; |
| |
| if (file->f_mode & FMODE_READ) { |
| struct seq_file *m = file->private_data; |
| |
| fgd = m->private; |
| seq_release(inode, file); |
| } else { |
| fgd = file->private_data; |
| } |
| |
| |
| if (file->f_mode & FMODE_WRITE) { |
| |
| parser = &fgd->parser; |
| |
| if (trace_parser_loaded((parser))) { |
| ret = ftrace_graph_set_hash(fgd->new_hash, |
| parser->buffer); |
| } |
| |
| trace_parser_put(parser); |
| |
| new_hash = __ftrace_hash_move(fgd->new_hash); |
| if (!new_hash) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| mutex_lock(&graph_lock); |
| |
| if (fgd->type == GRAPH_FILTER_FUNCTION) { |
| old_hash = rcu_dereference_protected(ftrace_graph_hash, |
| lockdep_is_held(&graph_lock)); |
| rcu_assign_pointer(ftrace_graph_hash, new_hash); |
| } else { |
| old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
| lockdep_is_held(&graph_lock)); |
| rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash); |
| } |
| |
| mutex_unlock(&graph_lock); |
| |
| /* Wait till all users are no longer using the old hash */ |
| synchronize_sched(); |
| |
| free_ftrace_hash(old_hash); |
| } |
| |
| out: |
| free_ftrace_hash(fgd->new_hash); |
| kfree(fgd); |
| |
| return ret; |
| } |
| |
| static int |
| ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) |
| { |
| struct ftrace_glob func_g; |
| struct dyn_ftrace *rec; |
| struct ftrace_page *pg; |
| struct ftrace_func_entry *entry; |
| int fail = 1; |
| int not; |
| |
| /* decode regex */ |
| func_g.type = filter_parse_regex(buffer, strlen(buffer), |
| &func_g.search, ¬); |
| |
| func_g.len = strlen(func_g.search); |
| |
| mutex_lock(&ftrace_lock); |
| |
| if (unlikely(ftrace_disabled)) { |
| mutex_unlock(&ftrace_lock); |
| return -ENODEV; |
| } |
| |
| do_for_each_ftrace_rec(pg, rec) { |
| |
| if (rec->flags & FTRACE_FL_DISABLED) |
| continue; |
| |
| if (ftrace_match_record(rec, &func_g, NULL, 0)) { |
| entry = ftrace_lookup_ip(hash, rec->ip); |
| |
| if (!not) { |
| fail = 0; |
| |
| if (entry) |
| continue; |
| if (add_hash_entry(hash, rec->ip) < 0) |
| goto out; |
| } else { |
| if (entry) { |
| free_hash_entry(hash, entry); |
| fail = 0; |
| } |
| } |
| } |
| } while_for_each_ftrace_rec(); |
| out: |
| mutex_unlock(&ftrace_lock); |
| |
| if (fail) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| static ssize_t |
| ftrace_graph_write(struct file *file, const char __user *ubuf, |
| size_t cnt, loff_t *ppos) |
| { |
| ssize_t read, ret = 0; |
| struct ftrace_graph_data *fgd = file->private_data; |
| struct trace_parser *parser; |
| |
| if (!cnt) |
| return 0; |
| |
| /* Read mode uses seq functions */ |
| if (file->f_mode & FMODE_READ) { |
| struct seq_file *m = file->private_data; |
| fgd = m->private; |
| } |
| |
| parser = &fgd->parser; |
| |
| read = trace_get_user(parser, ubuf, cnt, ppos); |
| |
| if (read >= 0 && trace_parser_loaded(parser) && |
| !trace_parser_cont(parser)) { |
| |
| ret = ftrace_graph_set_hash(fgd->new_hash, |
| parser->buffer); |
| trace_parser_clear(parser); |
| } |
| |
| if (!ret) |
| ret = read; |
| |
| return ret; |
| } |
| |
| static const struct file_operations ftrace_graph_fops = { |
| .open = ftrace_graph_open, |
| .read = seq_read, |
| .write = ftrace_graph_write, |
| .llseek = tracing_lseek, |
| .release = ftrace_graph_release, |
| }; |
| |
| static const struct file_operations ftrace_graph_notrace_fops = { |
| .open = ftrace_graph_notrace_open, |
| .read = seq_read, |
| .write = ftrace_graph_write, |
| .llseek = tracing_lseek, |
| .release = ftrace_graph_release, |
| }; |
| #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
| |
| void ftrace_create_filter_files(struct ftrace_ops *ops, |
| struct dentry *parent) |
| { |
| |
| trace_create_file("set_ftrace_filter", 0644, parent, |
| ops, &ftrace_filter_fops); |
| |
| trace_create_file("set_ftrace_notrace", 0644, parent, |
| ops, &ftrace_notrace_fops); |
| } |
| |
| /* |
| * The name "destroy_filter_files" is really a misnomer. Although |
| * in the future, it may actualy delete the files, but this is |
| * really intended to make sure the ops passed in are disabled |
| * and that when this function returns, the caller is free to |
| * free the ops. |
| * |
| * The "destroy" name is only to match the "create" name that this |
| * should be paired with. |
| */ |
| void ftrace_destroy_filter_files(struct ftrace_ops *ops) |
| { |
| mutex_lock(&ftrace_lock); |
| if (ops->flags & FTRACE_OPS_FL_ENABLED) |
| ftrace_shutdown(ops, 0); |
| ops->flags |= FTRACE_OPS_FL_DELETED; |
| mutex_unlock(&ftrace_lock); |
| } |
| |
| static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
| { |
| |
| trace_create_file("available_filter_functions", 0444, |
| d_tracer, NULL, &ftrace_avail_fops); |
| |
| trace_create_file("enabled_functions", 0444, |
| d_tracer, NULL, &ftrace_enabled_fops); |
| |
| ftrace_create_filter_files(&global_ops, d_tracer); |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| trace_create_file("set_graph_function", 0644, d_tracer, |
| NULL, |
| &ftrace_graph_fops); |
| trace_create_file("set_graph_notrace", 0644, d_tracer, |
| NULL, |
| &ftrace_graph_notrace_fops); |
| #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
| |
| return 0; |
| } |
| |
| static int ftrace_cmp_ips(const void *a, const void *b) |
| { |
| const unsigned long *ipa = a; |
| const unsigned long *ipb = b; |
| |
| if (*ipa > *ipb) |
| return 1; |
| if (*ipa < *ipb) |
| return -1; |
| return 0; |
| } |
| |
| static int ftrace_process_locs(struct module *mod, |
| unsigned long *start, |
| unsigned long *end) |
| { |
| struct ftrace_page *start_pg; |
| struct ftrace_page *pg; |
| struct dyn_ftrace *rec; |
| unsigned long count; |
| unsigned long *p; |
| unsigned long addr; |
| unsigned long flags = 0; /* Shut up gcc */ |
| int ret = -ENOMEM; |
| |
| count = end - start; |
| |
| if (!count) |
| return 0; |
| |
| sort(start, count, sizeof(*start), |
| ftrace_cmp_ips, NULL); |
| |
| start_pg = ftrace_allocate_pages(count); |
| if (!start_pg) |
| return -ENOMEM; |
| |
| mutex_lock(&ftrace_lock); |
| |
| /* |
| * Core and each module needs their own pages, as |
| * modules will free them when they are removed. |
| * Force a new page to be allocated for modules. |
| */ |
| if (!mod) { |
| WARN_ON(ftrace_pages || ftrace_pages_start); |
| /* First initialization */ |
| ftrace_pages = ftrace_pages_start = start_pg; |
| } else { |
| if (!ftrace_pages) |
| goto out; |
| |
| if (WARN_ON(ftrace_pages->next)) { |
| /* Hmm, we have free pages? */ |
| while (ftrace_pages->next) |
| ftrace_pages = ftrace_pages->next; |
| } |
| |
| ftrace_pages->next = start_pg; |
| } |
| |
| p = start; |
| pg = start_pg; |
| while (p < end) { |
| addr = ftrace_call_adjust(*p++); |
| /* |
| * Some architecture linkers will pad between |
| * the different mcount_loc sections of different |
| * object files to satisfy alignments. |
| * Skip any NULL pointers. |
| */ |
| if (!addr) |
| continue; |
| |
| if (pg->index == pg->size) { |
| /* We should have allocated enough */ |
| if (WARN_ON(!pg->next)) |
| break; |
| pg = pg->next; |
| } |
| |
| rec = &pg->records[pg->index++]; |
| rec->ip = addr; |
| } |
| |
| /* We should have used all pages */ |
| WARN_ON(pg->next); |
| |
| /* Assign the last page to ftrace_pages */ |
| ftrace_pages = pg; |
| |
| /* |
| * We only need to disable interrupts on start up |
| * because we are modifying code that an interrupt |
| * may execute, and the modification is not atomic. |
| * But for modules, nothing runs the code we modify |
| * until we are finished with it, and there's no |
| * reason to cause large interrupt latencies while we do it. |
| */ |
| if (!mod) |
| local_irq_save(flags); |
| ftrace_update_code(mod, start_pg); |
| if (!mod) |
| local_irq_restore(flags); |
| ret = 0; |
| out: |
| mutex_unlock(&ftrace_lock); |
| |
| return ret; |
| } |
| |
| struct ftrace_mod_func { |
| struct list_head list; |
| char *name; |
| unsigned long ip; |
| unsigned int size; |
| }; |
| |
| struct ftrace_mod_map { |
| struct rcu_head rcu; |
| struct list_head list; |
| struct module *mod; |
| unsigned long start_addr; |
| unsigned long end_addr; |
| struct list_head funcs; |
| unsigned int num_funcs; |
| }; |
| |
| #ifdef CONFIG_MODULES |
| |
| #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) |
| |
| static LIST_HEAD(ftrace_mod_maps); |
| |
| static int referenced_filters(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *ops; |
| int cnt = 0; |
| |
| for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { |
| if (ops_references_rec(ops, rec)) |
| cnt++; |
| } |
| |
| return cnt; |
| } |
| |
| static void |
| clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash) |
| { |
| struct ftrace_func_entry *entry; |
| struct dyn_ftrace *rec; |
| int i; |
| |
| if (ftrace_hash_empty(hash)) |
| return; |
| |
| for (i = 0; i < pg->index; i++) { |
| rec = &pg->records[i]; |
| entry = __ftrace_lookup_ip(hash, rec->ip); |
| /* |
| * Do not allow this rec to match again. |
| * Yeah, it may waste some memory, but will be removed |
| * if/when the hash is modified again. |
| */ |
| if (entry) |
| entry->ip = 0; |
| } |
| } |
| |
| /* Clear any records from hashs */ |
| static void clear_mod_from_hashes(struct ftrace_page *pg) |
| { |
| struct trace_array *tr; |
| |
| mutex_lock(&trace_types_lock); |
| list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
| if (!tr->ops || !tr->ops->func_hash) |
| continue; |
| mutex_lock(&tr->ops->func_hash->regex_lock); |
| clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash); |
| clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash); |
| mutex_unlock(&tr->ops->func_hash->regex_lock); |
| } |
| mutex_unlock(&trace_types_lock); |
| } |
| |
| static void ftrace_free_mod_map(struct rcu_head *rcu) |
| { |
| struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu); |
| struct ftrace_mod_func *mod_func; |
| struct ftrace_mod_func *n; |
| |
| /* All the contents of mod_map are now not visible to readers */ |
| list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) { |
| kfree(mod_func->name); |
| list_del(&mod_func->list); |
| kfree(mod_func); |
| } |
| |
| kfree(mod_map); |
| } |
| |
| void ftrace_release_mod(struct module *mod) |
| { |
| struct ftrace_mod_map *mod_map; |
| struct ftrace_mod_map *n; |
| struct dyn_ftrace *rec; |
| struct ftrace_page **last_pg; |
| struct ftrace_page *tmp_page = NULL; |
| struct ftrace_page *pg; |
| int order; |
| |
| mutex_lock(&ftrace_lock); |
| |
| if (ftrace_disabled) |
| goto out_unlock; |
| |
| list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) { |
| if (mod_map->mod == mod) { |
| list_del_rcu(&mod_map->list); |
| call_rcu_sched(&mod_map->rcu, ftrace_free_mod_map); |
| break; |
| } |
| } |
| |
| /* |
| * Each module has its own ftrace_pages, remove |
| * them from the list. |
| */ |
| last_pg = &ftrace_pages_start; |
| for (pg = ftrace_pages_start; pg; pg = *last_pg) { |
| rec = &pg->records[0]; |
| if (within_module_core(rec->ip, mod) || |
| within_module_init(rec->ip, mod)) { |
| /* |
| * As core pages are first, the first |
| * page should never be a module page. |
| */ |
| if (WARN_ON(pg == ftrace_pages_start)) |
| goto out_unlock; |
| |
| /* Check if we are deleting the last page */ |
| if (pg == ftrace_pages) |
| ftrace_pages = next_to_ftrace_page(last_pg); |
| |
| ftrace_update_tot_cnt -= pg->index; |
| *last_pg = pg->next; |
| |
| pg->next = tmp_page; |
| tmp_page = pg; |
| } else |
| last_pg = &pg->next; |
| } |
| out_unlock: |
| mutex_unlock(&ftrace_lock); |
| |
| for (pg = tmp_page; pg; pg = tmp_page) { |
| |
| /* Needs to be called outside of ftrace_lock */ |
| clear_mod_from_hashes(pg); |
| |
| order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
| free_pages((unsigned long)pg->records, order); |
| tmp_page = pg->next; |
| kfree(pg); |
| } |
| } |
| |
| void ftrace_module_enable(struct module *mod) |
| { |
| struct dyn_ftrace *rec; |
| struct ftrace_page *pg; |
| |
| mutex_lock(&ftrace_lock); |
| |
| if (ftrace_disabled) |
| goto out_unlock; |
| |
| /* |
| * If the tracing is enabled, go ahead and enable the record. |
| * |
| * The reason not to enable the record immediatelly is the |
| * inherent check of ftrace_make_nop/ftrace_make_call for |
| * correct previous instructions. Making first the NOP |
| * conversion puts the module to the correct state, thus |
| * passing the ftrace_make_call check. |
| * |
| * We also delay this to after the module code already set the |
| * text to read-only, as we now need to set it back to read-write |
| * so that we can modify the text. |
| */ |
| if (ftrace_start_up) |
| ftrace_arch_code_modify_prepare(); |
| |
| do_for_each_ftrace_rec(pg, rec) { |
| int cnt; |
| /* |
| * do_for_each_ftrace_rec() is a double loop. |
| * module text shares the pg. If a record is |
| * not part of this module, then skip this pg, |
| * which the "break" will do. |
| */ |
| if (!within_module_core(rec->ip, mod) && |
| !within_module_init(rec->ip, mod)) |
| break; |
| |
| cnt = 0; |
| |
| /* |
| * When adding a module, we need to check if tracers are |
| * currently enabled and if they are, and can trace this record, |
| * we need to enable the module functions as well as update the |
| * reference counts for those function records. |
| */ |
| if (ftrace_start_up) |
| cnt += referenced_filters(rec); |
| |
| /* This clears FTRACE_FL_DISABLED */ |
| rec->flags = cnt; |
| |
| if (ftrace_start_up && cnt) { |
| int failed = __ftrace_replace_code(rec, 1); |
| if (failed) { |
| ftrace_bug(failed, rec); |
| goto out_loop; |
| } |
| } |
| |
| } while_for_each_ftrace_rec(); |
| |
| out_loop: |
| if (ftrace_start_up) |
| ftrace_arch_code_modify_post_process(); |
| |
| out_unlock: |
| mutex_unlock(&ftrace_lock); |
| |
| process_cached_mods(mod->name); |
| } |
| |
| void ftrace_module_init(struct module *mod) |
| { |
| if (ftrace_disabled || !mod->num_ftrace_callsites) |
| return; |
| |
| ftrace_process_locs(mod, mod->ftrace_callsites, |
| mod->ftrace_callsites + mod->num_ftrace_callsites); |
| } |
| |
| static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, |
| struct dyn_ftrace *rec) |
| { |
| struct ftrace_mod_func *mod_func; |
| unsigned long symsize; |
| unsigned long offset; |
| char str[KSYM_SYMBOL_LEN]; |
| char *modname; |
| const char *ret; |
| |
| ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str); |
| if (!ret) |
| return; |
| |
| mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL); |
| if (!mod_func) |
| return; |
| |
| mod_func->name = kstrdup(str, GFP_KERNEL); |
| if (!mod_func->name) { |
| kfree(mod_func); |
| return; |
| } |
| |
| mod_func->ip = rec->ip - offset; |
| mod_func->size = symsize; |
| |
| mod_map->num_funcs++; |
| |
| list_add_rcu(&mod_func->list, &mod_map->funcs); |
| } |
| |
| static struct ftrace_mod_map * |
| allocate_ftrace_mod_map(struct module *mod, |
| unsigned long start, unsigned long end) |
| { |
| struct ftrace_mod_map *mod_map; |
| |
| mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL); |
| if (!mod_map) |
| return NULL; |
| |
| mod_map->mod = mod; |
| mod_map->start_addr = start; |
| mod_map->end_addr = end; |
| mod_map->num_funcs = 0; |
| |
| INIT_LIST_HEAD_RCU(&mod_map->funcs); |
| |
| list_add_rcu(&mod_map->list, &ftrace_mod_maps); |
| |
| return mod_map; |
| } |
| |
| static const char * |
| ftrace_func_address_lookup(struct ftrace_mod_map *mod_map, |
| unsigned long addr, unsigned long *size, |
| unsigned long *off, char *sym) |
| { |
| struct ftrace_mod_func *found_func = NULL; |
| struct ftrace_mod_func *mod_func; |
| |
| list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { |
| if (addr >= mod_func->ip && |
| addr < mod_func->ip + mod_func->size) { |
| found_func = mod_func; |
| break; |
| } |
| } |
| |
| if (found_func) { |
| if (size) |
| *size = found_func->size; |
| if (off) |
| *off = addr - found_func->ip; |
| if (sym) |
| strlcpy(sym, found_func->name, KSYM_NAME_LEN); |
| |
| return found_func->name; |
| } |
| |
| return NULL; |
| } |
| |
| const char * |
| ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, |
| unsigned long *off, char **modname, char *sym) |
| { |
| struct ftrace_mod_map *mod_map; |
| const char *ret = NULL; |
| |
| /* mod_map is freed via call_rcu_sched() */ |
| preempt_disable(); |
| list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { |
| ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym); |
| if (ret) { |
| if (modname) |
| *modname = mod_map->mod->name; |
| break; |
| } |
| } |
| preempt_enable(); |
| |
| return ret; |
| } |
| |
| int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
| char *type, char *name, |
| char *module_name, int *exported) |
| { |
| struct ftrace_mod_map *mod_map; |
| struct ftrace_mod_func *mod_func; |
| |
| preempt_disable(); |
| list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { |
| |
| if (symnum >= mod_map->num_funcs) { |
| symnum -= mod_map->num_funcs; |
| continue; |
| } |
| |
| list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { |
| if (symnum > 1) { |
| symnum--; |
| continue; |
| } |
| |
| *value = mod_func->ip; |
| *type = 'T'; |
| strlcpy(name, mod_func->name, KSYM_NAME_LEN); |
| strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN); |
| *exported = 1; |
| preempt_enable(); |
| return 0; |
| } |
| WARN_ON(1); |
| break; |
| } |
| preempt_enable(); |
| return -ERANGE; |
| } |
| |
| #else |
| static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, |
| struct dyn_ftrace *rec) { } |
| static inline struct ftrace_mod_map * |
| allocate_ftrace_mod_map(struct module *mod, |
| unsigned long start, unsigned long end) |
| { |
| return NULL; |
| } |
| #endif /* CONFIG_MODULES */ |
| |
| struct ftrace_init_func { |
| struct list_head list; |
| unsigned long ip; |
| }; |
| |
| /* Clear any init ips from hashes */ |
| static void |
| clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash) |
| { |
| struct ftrace_func_entry *entry; |
| |
| if (ftrace_hash_empty(hash)) |
| return; |
| |
| entry = __ftrace_lookup_ip(hash, func->ip); |
| |
| /* |
| * Do not allow this rec to match again. |
| * Yeah, it may waste some memory, but will be removed |
| * if/when the hash is modified again. |
| */ |
| if (entry) |
| entry->ip = 0; |
| } |
| |
| static void |
| clear_func_from_hashes(struct ftrace_init_func *func) |
| { |
| struct trace_array *tr; |
| |
| mutex_lock(&trace_types_lock); |
| list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
| if (!tr->ops || !tr->ops->func_hash) |
| continue; |
| mutex_lock(&tr->ops->func_hash->regex_lock); |
| clear_func_from_hash(func, tr->ops->func_hash->filter_hash); |
| clear_func_from_hash(func, tr->ops->func_hash->notrace_hash); |
| mutex_unlock(&tr->ops->func_hash->regex_lock); |
| } |
| mutex_unlock(&trace_types_lock); |
| } |
| |
| static void add_to_clear_hash_list(struct list_head *clear_list, |
| struct dyn_ftrace *rec) |
| { |
| struct ftrace_init_func *func; |
| |
| func = kmalloc(sizeof(*func), GFP_KERNEL); |
| if (!func) { |
| WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n"); |
| return; |
| } |
| |
| func->ip = rec->ip; |
| list_add(&func->list, clear_list); |
| } |
| |
| void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) |
| { |
| unsigned long start = (unsigned long)(start_ptr); |
| unsigned long end = (unsigned long)(end_ptr); |
| struct ftrace_page **last_pg = &ftrace_pages_start; |
| struct ftrace_page *pg; |
| struct dyn_ftrace *rec; |
| struct dyn_ftrace key; |
| struct ftrace_mod_map *mod_map = NULL; |
| struct ftrace_init_func *func, *func_next; |
| struct list_head clear_hash; |
| int order; |
| |
| INIT_LIST_HEAD(&clear_hash); |
| |
| key.ip = start; |
| key.flags = end; /* overload flags, as it is unsigned long */ |
| |
| mutex_lock(&ftrace_lock); |
| |
| /* |
| * If we are freeing module init memory, then check if |
| * any tracer is active. If so, we need to save a mapping of |
| * the module functions being freed with the address. |
| */ |
| if (mod && ftrace_ops_list != &ftrace_list_end) |
| mod_map = allocate_ftrace_mod_map(mod, start, end); |
| |
| for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) { |
| if (end < pg->records[0].ip || |
| start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) |
| continue; |
| again: |
| rec = bsearch(&key, pg->records, pg->index, |
| sizeof(struct dyn_ftrace), |
| ftrace_cmp_recs); |
| if (!rec) |
| continue; |
| |
| /* rec will be cleared from hashes after ftrace_lock unlock */ |
| add_to_clear_hash_list(&clear_hash, rec); |
| |
| if (mod_map) |
| save_ftrace_mod_rec(mod_map, rec); |
| |
| pg->index--; |
| ftrace_update_tot_cnt--; |
| if (!pg->index) { |
| *last_pg = pg->next; |
| order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
| free_pages((unsigned long)pg->records, order); |
| kfree(pg); |
| pg = container_of(last_pg, struct ftrace_page, next); |
| if (!(*last_pg)) |
| ftrace_pages = pg; |
| continue; |
| } |
| memmove(rec, rec + 1, |
| (pg->index - (rec - pg->records)) * sizeof(*rec)); |
| /* More than one function may be in this block */ |
| goto again; |
| } |
| mutex_unlock(&ftrace_lock); |
| |
| list_for_each_entry_safe(func, func_next, &clear_hash, list) { |
| clear_func_from_hashes(func); |
| kfree(func); |
| } |
| } |
| |
| void __init ftrace_free_init_mem(void) |
| { |
| void *start = (void *)(&__init_begin); |
| void *end = (void *)(&__init_end); |
| |
| ftrace_free_mem(NULL, start, end); |
| } |
| |
| void __init ftrace_init(void) |
| { |
| extern unsigned long __start_mcount_loc[]; |
| extern unsigned long __stop_mcount_loc[]; |
| unsigned long count, flags; |
| int ret; |
| |
| local_irq_save(flags); |
| ret = ftrace_dyn_arch_init(); |
| local_irq_restore(flags); |
| if (ret) |
| goto failed; |
| |
| count = __stop_mcount_loc - __start_mcount_loc; |
| if (!count) { |
| pr_info("ftrace: No functions to be traced?\n"); |
| goto failed; |
| } |
| |
| pr_info("ftrace: allocating %ld entries in %ld pages\n", |
| count, count / ENTRIES_PER_PAGE + 1); |
| |
| last_ftrace_enabled = ftrace_enabled = 1; |
| |
| ret = ftrace_process_locs(NULL, |
| __start_mcount_loc, |
| __stop_mcount_loc); |
| |
| set_ftrace_early_filters(); |
| |
| return; |
| failed: |
| ftrace_disabled = 1; |
| } |
| |
| /* Do nothing if arch does not support this */ |
| void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) |
| { |
| } |
| |
| static void ftrace_update_trampoline(struct ftrace_ops *ops) |
| { |
| arch_ftrace_update_trampoline(ops); |
| } |
| |
| void ftrace_init_trace_array(struct trace_array *tr) |
| { |
| INIT_LIST_HEAD(&tr->func_probes); |
| INIT_LIST_HEAD(&tr->mod_trace); |
| INIT_LIST_HEAD(&tr->mod_notrace); |
| } |
| #else |
| |
| static struct ftrace_ops global_ops = { |
| .func = ftrace_stub, |
| .flags = FTRACE_OPS_FL_RECURSION_SAFE | |
| FTRACE_OPS_FL_INITIALIZED | |
| FTRACE_OPS_FL_PID, |
| }; |
| |
| static int __init ftrace_nodyn_init(void) |
| { |
| ftrace_enabled = 1; |
| return 0; |
| } |
| core_initcall(ftrace_nodyn_init); |
| |
| static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
| static inline void ftrace_startup_enable(int command) { } |
| static inline void ftrace_startup_all(int command) { } |
| /* Keep as macros so we do not need to define the commands */ |
| # define ftrace_startup(ops, command) \ |
| ({ \ |
| int ___ret = __register_ftrace_function(ops); \ |
| if (!___ret) \ |
| (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ |
| ___ret; \ |
| }) |
| # define ftrace_shutdown(ops, command) \ |
| ({ \ |
| int ___ret = __unregister_ftrace_function(ops); \ |
| if (!___ret) \ |
| (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \ |
| ___ret; \ |
| }) |
| |
| # define ftrace_startup_sysctl() do { } while (0) |
| # define ftrace_shutdown_sysctl() do { } while (0) |
| |
| static inline int |
| ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
| { |
| return 1; |
| } |
| |
| static void ftrace_update_trampoline(struct ftrace_ops *ops) |
| { |
| } |
| |
| #endif /* CONFIG_DYNAMIC_FTRACE */ |
| |
| __init void ftrace_init_global_array_ops(struct trace_array *tr) |
| { |
| tr->ops = &global_ops; |
| tr->ops->private = tr; |
| ftrace_init_trace_array(tr); |
| } |
| |
| void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) |
| { |
| /* If we filter on pids, update to use the pid function */ |
| if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { |
| if (WARN_ON(tr->ops->func != ftrace_stub)) |
| printk("ftrace ops had %pS for function\n", |
| tr->ops->func); |
| } |
| tr->ops->func = func; |
| tr->ops->private = tr; |
| } |
| |
| void ftrace_reset_array_ops(struct trace_array *tr) |
| { |
| tr->ops->func = ftrace_stub; |
| } |
| |
| static inline void |
| __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
| struct ftrace_ops *ignored, struct pt_regs *regs) |
| { |
| struct ftrace_ops *op; |
| int bit; |
| |
| bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
| if (bit < 0) |
| return; |
| |
| /* |
| * Some of the ops may be dynamically allocated, |
| * they must be freed after a synchronize_sched(). |
| */ |
| preempt_disable_notrace(); |
| |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| /* |
| * Check the following for each ops before calling their func: |
| * if RCU flag is set, then rcu_is_watching() must be true |
| * if PER_CPU is set, then ftrace_function_local_disable() |
| * must be false |
| * Otherwise test if the ip matches the ops filter |
| * |
| * If any of the above fails then the op->func() is not executed. |
| */ |
| if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) && |
| ftrace_ops_test(op, ip, regs)) { |
| if (FTRACE_WARN_ON(!op->func)) { |
| pr_warn("op=%p %pS\n", op, op); |
| goto out; |
| } |
| op->func(ip, parent_ip, op, regs); |
| } |
| } while_for_each_ftrace_op(op); |
| out: |
| preempt_enable_notrace(); |
| trace_clear_recursion(bit); |
| } |
| |
| /* |
| * Some archs only support passing ip and parent_ip. Even though |
| * the list function ignores the op parameter, we do not want any |
| * C side effects, where a function is called without the caller |
| * sending a third parameter. |
| * Archs are to support both the regs and ftrace_ops at the same time. |
| * If they support ftrace_ops, it is assumed they support regs. |
| * If call backs want to use regs, they must either check for regs |
| * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
| * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. |
| * An architecture can pass partial regs with ftrace_ops and still |
| * set the ARCH_SUPPORTS_FTRACE_OPS. |
| */ |
| #if ARCH_SUPPORTS_FTRACE_OPS |
| static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
| struct ftrace_ops *op, struct pt_regs *regs) |
| { |
| __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
| } |
| #else |
| static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) |
| { |
| __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
| } |
| #endif |
| |
| /* |
| * If there's only one function registered but it does not support |
| * recursion, needs RCU protection and/or requires per cpu handling, then |
| * this function will be called by the mcount trampoline. |
| */ |
| static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, |
| struct ftrace_ops *op, struct pt_regs *regs) |
| { |
| int bit; |
| |
| if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching()) |
| return; |
| |
| bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
| if (bit < 0) |
| return; |
| |
| preempt_disable_notrace(); |
| |
| op->func(ip, parent_ip, op, regs); |
| |
| preempt_enable_notrace(); |
| trace_clear_recursion(bit); |
| } |
| |
| /** |
| * ftrace_ops_get_func - get the function a trampoline should call |
| * @ops: the ops to get the function for |
| * |
| * Normally the mcount trampoline will call the ops->func, but there |
| * are times that it should not. For example, if the ops does not |
| * have its own recursion protection, then it should call the |
| * ftrace_ops_assist_func() instead. |
| * |
| * Returns the function that the trampoline should call for @ops. |
| */ |
| ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) |
| { |
| /* |
| * If the function does not handle recursion, needs to be RCU safe, |
| * or does per cpu logic, then we need to call the assist handler. |
| */ |
| if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) || |
| ops->flags & FTRACE_OPS_FL_RCU) |
| return ftrace_ops_assist_func; |
| |
| return ops->func; |
| } |
| |
| static void |
| ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, |
| struct task_struct *prev, struct task_struct *next) |
| { |
| struct trace_array *tr = data; |
| struct trace_pid_list *pid_list; |
| |
| pid_list = rcu_dereference_sched(tr->function_pids); |
| |
| this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid, |
| trace_ignore_this_task(pid_list, next)); |
| } |
| |
| static void |
| ftrace_pid_follow_sched_process_fork(void *data, |
| struct task_struct *self, |
| struct task_struct *task) |
| { |
| struct trace_pid_list *pid_list; |
| struct trace_array *tr = data; |
| |
| pid_list = rcu_dereference_sched(tr->function_pids); |
| trace_filter_add_remove_task(pid_list, self, task); |
| } |
| |
| static void |
| ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) |
| { |
| struct trace_pid_list *pid_list; |
| struct trace_array *tr = data; |
| |
| pid_list = rcu_dereference_sched(tr->function_pids); |
| trace_filter_add_remove_task(pid_list, NULL, task); |
| } |
| |
| void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) |
| { |
| if (enable) { |
| register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, |
| tr); |
| register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, |
| tr); |
| } else { |
| unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, |
| tr); |
| unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, |
| tr); |
| } |
| } |
| |
| static void clear_ftrace_pids(struct trace_array *tr) |
| { |
| struct trace_pid_list *pid_list; |
| int cpu; |
| |
| pid_list = rcu_dereference_protected(tr->function_pids, |
| lockdep_is_held(&ftrace_lock)); |
| if (!pid_list) |
| return; |
| |
| unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); |
| |
| for_each_possible_cpu(cpu) |
| per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false; |
| |
| rcu_assign_pointer(tr->function_pids, NULL); |
| |
| /* Wait till all users are no longer using pid filtering */ |
| synchronize_sched(); |
| |
| trace_free_pid_list(pid_list); |
| } |
| |
| void ftrace_clear_pids(struct trace_array *tr) |
| { |
| mutex_lock(&ftrace_lock); |
| |
| clear_ftrace_pids(tr); |
| |
| mutex_unlock(&ftrace_lock); |
| } |
| |
| static void ftrace_pid_reset(struct trace_array *tr) |
| { |
| mutex_lock(&ftrace_lock); |
| clear_ftrace_pids(tr); |
| |
| ftrace_update_pid_func(); |
| ftrace_startup_all(0); |
| |
| mutex_unlock(&ftrace_lock); |
| } |
| |
| /* Greater than any max PID */ |
| #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1) |
| |
| static void *fpid_start(struct seq_file *m, loff_t *pos) |
| __acquires(RCU) |
| { |
| struct trace_pid_list *pid_list; |
| struct trace_array *tr = m->private; |
| |
| mutex_lock(&ftrace_lock); |
| rcu_read_lock_sched(); |
| |
| pid_list = rcu_dereference_sched(tr->function_pids); |
| |
| if (!pid_list) |
| return !(*pos) ? FTRACE_NO_PIDS : NULL; |
| |
| return trace_pid_start(pid_list, pos); |
| } |
| |
| static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) |
| { |
| struct trace_array *tr = m->private; |
| struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids); |
| |
| if (v == FTRACE_NO_PIDS) |
| return NULL; |
| |
| return trace_pid_next(pid_list, v, pos); |
| } |
| |
| static void fpid_stop(struct seq_file *m, void *p) |
| __releases(RCU) |
| { |
| rcu_read_unlock_sched(); |
| mutex_unlock(&ftrace_lock); |
| } |
| |
| static int fpid_show(struct seq_file *m, void *v) |
| { |
| if (v == FTRACE_NO_PIDS) { |
| seq_puts(m, "no pid\n"); |
| return 0; |
| } |
| |
| return trace_pid_show(m, v); |
| } |
| |
| static const struct seq_operations ftrace_pid_sops = { |
| .start = fpid_start, |
| .next = fpid_next, |
| .stop = fpid_stop, |
| .show = fpid_show, |
| }; |
| |
| static int |
| ftrace_pid_open(struct inode *inode, struct file *file) |
| { |
| struct trace_array *tr = inode->i_private; |
| struct seq_file *m; |
| int ret = 0; |
| |
| if (trace_array_get(tr) < 0) |
| return -ENODEV; |
| |
| if ((file->f_mode & FMODE_WRITE) && |
| (file->f_flags & O_TRUNC)) |
| ftrace_pid_reset(tr); |
| |
| ret = seq_open(file, &ftrace_pid_sops); |
| if (ret < 0) { |
| trace_array_put(tr); |
| } else { |
| m = file->private_data; |
| /* copy tr over to seq ops */ |
| m->private = tr; |
| } |
| |
| return ret; |
| } |
| |
| static void ignore_task_cpu(void *data) |
| { |
| struct trace_array *tr = data; |
| struct trace_pid_list *pid_list; |
| |
| /* |
| * This function is called by on_each_cpu() while the |
| * event_mutex is held. |
| */ |
| pid_list = rcu_dereference_protected(tr->function_pids, |
| mutex_is_locked(&ftrace_lock)); |
| |
| this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid, |
| trace_ignore_this_task(pid_list, current)); |
| } |
| |
| static ssize_t |
| ftrace_pid_write(struct file *filp, const char __user *ubuf, |
| size_t cnt, loff_t *ppos) |
| { |
| struct seq_file *m = filp->private_data; |
| struct trace_array *tr = m->private; |
| struct trace_pid_list *filtered_pids = NULL; |
| struct trace_pid_list *pid_list; |
| ssize_t ret; |
| |
| if (!cnt) |
| return 0; |
| |
| mutex_lock(&ftrace_lock); |
| |
| filtered_pids = rcu_dereference_protected(tr->function_pids, |
| lockdep_is_held(&ftrace_lock)); |
| |
| ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); |
| if (ret < 0) |
| goto out; |
| |
| rcu_assign_pointer(tr->function_pids, pid_list); |
| |
| if (filtered_pids) { |
| synchronize_sched(); |
| trace_free_pid_list(filtered_pids); |
| } else if (pid_list) { |
| /* Register a probe to set whether to ignore the tracing of a task */ |
| register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); |
| } |
| |
| /* |
| * Ignoring of pids is done at task switch. But we have to |
| * check for those tasks that are currently running. |
| * Always do this in case a pid was appended or removed. |
| */ |
| on_each_cpu(ignore_task_cpu, tr, 1); |
| |
| ftrace_update_pid_func(); |
| ftrace_startup_all(0); |
| out: |
| mutex_unlock(&ftrace_lock); |
| |
| if (ret > 0) |
| *ppos += ret; |
| |
| return ret; |
| } |
| |
| static int |
| ftrace_pid_release(struct inode *inode, struct file *file) |
| { |
| struct trace_array *tr = inode->i_private; |
| |
| trace_array_put(tr); |
| |
| return seq_release(inode, file); |
| } |
| |
| static const struct file_operations ftrace_pid_fops = { |
| .open = ftrace_pid_open, |
| .write = ftrace_pid_write, |
| .read = seq_read, |
| .llseek = tracing_lseek, |
| .release = ftrace_pid_release, |
| }; |
| |
| void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
| { |
| trace_create_file("set_ftrace_pid", 0644, d_tracer, |
| tr, &ftrace_pid_fops); |
| } |
| |
| void __init ftrace_init_tracefs_toplevel(struct trace_array *tr, |
| struct dentry *d_tracer) |
| { |
| /* Only the top level directory has the dyn_tracefs and profile */ |
| WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); |
| |
| ftrace_init_dyn_tracefs(d_tracer); |
| ftrace_profile_tracefs(d_tracer); |
| } |
| |
| /** |
| * ftrace_kill - kill ftrace |
| * |
| * This function should be used by panic code. It stops ftrace |
| * but in a not so nice way. If you need to simply kill ftrace |
| * from a non-atomic section, use ftrace_kill. |
| */ |
| void ftrace_kill(void) |
| { |
| ftrace_disabled = 1; |
| ftrace_enabled = 0; |
| clear_ftrace_function(); |
| } |
| |
| /** |
| * Test if ftrace is dead or not. |
| */ |
| int ftrace_is_dead(void) |
| { |
| return ftrace_disabled; |
| } |
| |
| /** |
| * register_ftrace_function - register a function for profiling |
| * @ops - ops structure that holds the function for profiling. |
| * |
| * Register a function to be called by all functions in the |
| * kernel. |
| * |
| * Note: @ops->func and all the functions it calls must be labeled |
| * with "notrace", otherwise it will go into a |
| * recursive loop. |
| */ |
| int register_ftrace_function(struct ftrace_ops *ops) |
| { |
| int ret = -1; |
| |
| ftrace_ops_init(ops); |
| |
| mutex_lock(&ftrace_lock); |
| |
| ret = ftrace_startup(ops, 0); |
| |
| mutex_unlock(&ftrace_lock); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(register_ftrace_function); |
| |
| /** |
| * unregister_ftrace_function - unregister a function for profiling. |
| * @ops - ops structure that holds the function to unregister |
| * |
| * Unregister a function that was added to be called by ftrace profiling. |
| */ |
| int unregister_ftrace_function(struct ftrace_ops *ops) |
| { |
| int ret; |
| |
| mutex_lock(&ftrace_lock); |
| ret = ftrace_shutdown(ops, 0); |
| mutex_unlock(&ftrace_lock); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
| |
| int |
| ftrace_enable_sysctl(struct ctl_table *table, int write, |
| void __user *buffer, size_t *lenp, |
| loff_t *ppos) |
| { |
| int ret = -ENODEV; |
| |
| mutex_lock(&ftrace_lock); |
| |
| if (unlikely(ftrace_disabled)) |
| goto out; |
| |
| ret = proc_dointvec(table, write, buffer, lenp, ppos); |
| |
| if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
| goto out; |
| |
| last_ftrace_enabled = !!ftrace_enabled; |
| |
| if (ftrace_enabled) { |
| |
| /* we are starting ftrace again */ |
| if (rcu_dereference_protected(ftrace_ops_list, |
| lockdep_is_held(&ftrace_lock)) != &ftrace_list_end) |
| update_ftrace_function(); |
| |
| ftrace_startup_sysctl(); |
| |
| } else { |
| /* stopping ftrace calls (just send to ftrace_stub) */ |
| ftrace_trace_function = ftrace_stub; |
| |
| ftrace_shutdown_sysctl(); |
| } |
| |
| out: |
| mutex_unlock(&ftrace_lock); |
| return ret; |
| } |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| |
| static struct ftrace_ops graph_ops = { |
| .func = ftrace_stub, |
| .flags = FTRACE_OPS_FL_RECURSION_SAFE | |
| FTRACE_OPS_FL_INITIALIZED | |
| FTRACE_OPS_FL_PID | |
| FTRACE_OPS_FL_STUB, |
| #ifdef FTRACE_GRAPH_TRAMP_ADDR |
| .trampoline = FTRACE_GRAPH_TRAMP_ADDR, |
| /* trampoline_size is only needed for dynamically allocated tramps */ |
| #endif |
| ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash) |
| }; |
| |
| void ftrace_graph_sleep_time_control(bool enable) |
| { |
| fgraph_sleep_time = enable; |
| } |
| |
| void ftrace_graph_graph_time_control(bool enable) |
| { |
| fgraph_graph_time = enable; |
| } |
| |
| int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
| { |
| return 0; |
| } |
| |
| /* The callbacks that hook a function */ |
| trace_func_graph_ret_t ftrace_graph_return = |
| (trace_func_graph_ret_t)ftrace_stub; |
| trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
| static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub; |
| |
| /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ |
| static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) |
| { |
| int i; |
| int ret = 0; |
| int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; |
| struct task_struct *g, *t; |
| |
| for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { |
| ret_stack_list[i] = |
| kmalloc_array(FTRACE_RETFUNC_DEPTH, |
| sizeof(struct ftrace_ret_stack), |
| GFP_KERNEL); |
| if (!ret_stack_list[i]) { |
| start = 0; |
| end = i; |
| ret = -ENOMEM; |
| goto free; |
| } |
| } |
| |
| read_lock(&tasklist_lock); |
| do_each_thread(g, t) { |
| if (start == end) { |
| ret = -EAGAIN; |
| goto unlock; |
| } |
| |
| if (t->ret_stack == NULL) { |
| atomic_set(&t->tracing_graph_pause, 0); |
| atomic_set(&t->trace_overrun, 0); |
| t->curr_ret_stack = -1; |
| /* Make sure the tasks see the -1 first: */ |
| smp_wmb(); |
| t->ret_stack = ret_stack_list[start++]; |
| } |
| } while_each_thread(g, t); |
| |
| unlock: |
| read_unlock(&tasklist_lock); |
| free: |
| for (i = start; i < end; i++) |
| kfree(ret_stack_list[i]); |
| return ret; |
| } |
| |
| static void |
| ftrace_graph_probe_sched_switch(void *ignore, bool preempt, |
| struct task_struct *prev, struct task_struct *next) |
| { |
| unsigned long long timestamp; |
| int index; |
| |
| /* |
| * Does the user want to count the time a function was asleep. |
| * If so, do not update the time stamps. |
| */ |
| if (fgraph_sleep_time) |
| return; |
| |
| timestamp = trace_clock_local(); |
| |
| prev->ftrace_timestamp = timestamp; |
| |
| /* only process tasks that we timestamped */ |
| if (!next->ftrace_timestamp) |
| return; |
| |
| /* |
| * Update all the counters in next to make up for the |
| * time next was sleeping. |
| */ |
| timestamp -= next->ftrace_timestamp; |
| |
| for (index = next->curr_ret_stack; index >= 0; index--) |
| next->ret_stack[index].calltime += timestamp; |
| } |
| |
| /* Allocate a return stack for each task */ |
| static int start_graph_tracing(void) |
| { |
| struct ftrace_ret_stack **ret_stack_list; |
| int ret, cpu; |
| |
| ret_stack_list = kmalloc_array(FTRACE_RETSTACK_ALLOC_SIZE, |
| sizeof(struct ftrace_ret_stack *), |
| GFP_KERNEL); |
| |
| if (!ret_stack_list) |
| return -ENOMEM; |
| |
| /* The cpu_boot init_task->ret_stack will never be freed */ |
| for_each_online_cpu(cpu) { |
| if (!idle_task(cpu)->ret_stack) |
| ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
| } |
| |
| do { |
| ret = alloc_retstack_tasklist(ret_stack_list); |
| } while (ret == -EAGAIN); |
| |
| if (!ret) { |
| ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
| if (ret) |
| pr_info("ftrace_graph: Couldn't activate tracepoint" |
| " probe to kernel_sched_switch\n"); |
| } |
| |
| kfree(ret_stack_list); |
| return ret; |
| } |
| |
| /* |
| * Hibernation protection. |
| * The state of the current task is too much unstable during |
| * suspend/restore to disk. We want to protect against that. |
| */ |
| static int |
| ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, |
| void *unused) |
| { |
| switch (state) { |
| case PM_HIBERNATION_PREPARE: |
| pause_graph_tracing(); |
| break; |
| |
| case PM_POST_HIBERNATION: |
| unpause_graph_tracing(); |
| break; |
| } |
| return NOTIFY_DONE; |
| } |
| |
| static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace) |
| { |
| if (!ftrace_ops_test(&global_ops, trace->func, NULL)) |
| return 0; |
| return __ftrace_graph_entry(trace); |
| } |
| |
| /* |
| * The function graph tracer should only trace the functions defined |
| * by set_ftrace_filter and set_ftrace_notrace. If another function |
| * tracer ops is registered, the graph tracer requires testing the |
| * function against the global ops, and not just trace any function |
| * that any ftrace_ops registered. |
| */ |
| static void update_function_graph_func(void) |
| { |
| struct ftrace_ops *op; |
| bool do_test = false; |
| |
| /* |
| * The graph and global ops share the same set of functions |
| * to test. If any other ops is on the list, then |
| * the graph tracing needs to test if its the function |
| * it should call. |
| */ |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| if (op != &global_ops && op != &graph_ops && |
| op != &ftrace_list_end) { |
| do_test = true; |
| /* in double loop, break out with goto */ |
| goto out; |
| } |
| } while_for_each_ftrace_op(op); |
| out: |
| if (do_test) |
| ftrace_graph_entry = ftrace_graph_entry_test; |
| else |
| ftrace_graph_entry = __ftrace_graph_entry; |
| } |
| |
| static struct notifier_block ftrace_suspend_notifier = { |
| .notifier_call = ftrace_suspend_notifier_call, |
| }; |
| |
| int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
| trace_func_graph_ent_t entryfunc) |
| { |
| int ret = 0; |
| |
| mutex_lock(&ftrace_lock); |
| |
| /* we currently allow only one tracer registered at a time */ |
| if (ftrace_graph_active) { |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| register_pm_notifier(&ftrace_suspend_notifier); |
| |
| ftrace_graph_active++; |
| ret = start_graph_tracing(); |
| if (ret) { |
| ftrace_graph_active--; |
| goto out; |
| } |
| |
| ftrace_graph_return = retfunc; |
| |
| /* |
| * Update the indirect function to the entryfunc, and the |
| * function that gets called to the entry_test first. Then |
| * call the update fgraph entry function to determine if |
| * the entryfunc should be called directly or not. |
| */ |
| __ftrace_graph_entry = entryfunc; |
| ftrace_graph_entry = ftrace_graph_entry_test; |
| update_function_graph_func(); |
| |
| ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET); |
| out: |
| mutex_unlock(&ftrace_lock); |
| return ret; |
| } |
| |
| void unregister_ftrace_graph(void) |
| { |
| mutex_lock(&ftrace_lock); |
| |
| if (unlikely(!ftrace_graph_active)) |
| goto out; |
| |
| ftrace_graph_active--; |
| ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
| ftrace_graph_entry = ftrace_graph_entry_stub; |
| __ftrace_graph_entry = ftrace_graph_entry_stub; |
| ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET); |
| unregister_pm_notifier(&ftrace_suspend_notifier); |
| unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
| |
| out: |
| mutex_unlock(&ftrace_lock); |
| } |
| |
| static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
| |
| static void |
| graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) |
| { |
| atomic_set(&t->tracing_graph_pause, 0); |
| atomic_set(&t->trace_overrun, 0); |
| t->ftrace_timestamp = 0; |
| /* make curr_ret_stack visible before we add the ret_stack */ |
| smp_wmb(); |
| t->ret_stack = ret_stack; |
| } |
| |
| /* |
| * Allocate a return stack for the idle task. May be the first |
| * time through, or it may be done by CPU hotplug online. |
| */ |
| void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) |
| { |
| t->curr_ret_stack = -1; |
| /* |
| * The idle task has no parent, it either has its own |
| * stack or no stack at all. |
| */ |
| if (t->ret_stack) |
| WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); |
| |
| if (ftrace_graph_active) { |
| struct ftrace_ret_stack *ret_stack; |
| |
| ret_stack = per_cpu(idle_ret_stack, cpu); |
| if (!ret_stack) { |
| ret_stack = |
| kmalloc_array(FTRACE_RETFUNC_DEPTH, |
| sizeof(struct ftrace_ret_stack), |
| GFP_KERNEL); |
| if (!ret_stack) |
| return; |
| per_cpu(idle_ret_stack, cpu) = ret_stack; |
| } |
| graph_init_task(t, ret_stack); |
| } |
| } |
| |
| /* Allocate a return stack for newly created task */ |
| void ftrace_graph_init_task(struct task_struct *t) |
| { |
| /* Make sure we do not use the parent ret_stack */ |
| t->ret_stack = NULL; |
| t->curr_ret_stack = -1; |
| |
| if (ftrace_graph_active) { |
| struct ftrace_ret_stack *ret_stack; |
| |
| ret_stack = kmalloc_array(FTRACE_RETFUNC_DEPTH, |
| sizeof(struct ftrace_ret_stack), |
| GFP_KERNEL); |
| if (!ret_stack) |
| return; |
| graph_init_task(t, ret_stack); |
| } |
| } |
| |
| void ftrace_graph_exit_task(struct task_struct *t) |
| { |
| struct ftrace_ret_stack *ret_stack = t->ret_stack; |
| |
| t->ret_stack = NULL; |
| /* NULL must become visible to IRQs before we free it: */ |
| barrier(); |
| |
| kfree(ret_stack); |
| } |
| #endif |