| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com |
| * Copyright (c) 2016 Facebook |
| */ |
| #include <linux/kernel.h> |
| #include <linux/types.h> |
| #include <linux/slab.h> |
| #include <linux/bpf.h> |
| #include <linux/bpf_perf_event.h> |
| #include <linux/filter.h> |
| #include <linux/uaccess.h> |
| #include <linux/ctype.h> |
| #include <linux/kprobes.h> |
| #include <linux/syscalls.h> |
| #include <linux/error-injection.h> |
| |
| #include "trace_probe.h" |
| #include "trace.h" |
| |
| #ifdef CONFIG_MODULES |
| struct bpf_trace_module { |
| struct module *module; |
| struct list_head list; |
| }; |
| |
| static LIST_HEAD(bpf_trace_modules); |
| static DEFINE_MUTEX(bpf_module_mutex); |
| |
| static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) |
| { |
| struct bpf_raw_event_map *btp, *ret = NULL; |
| struct bpf_trace_module *btm; |
| unsigned int i; |
| |
| mutex_lock(&bpf_module_mutex); |
| list_for_each_entry(btm, &bpf_trace_modules, list) { |
| for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { |
| btp = &btm->module->bpf_raw_events[i]; |
| if (!strcmp(btp->tp->name, name)) { |
| if (try_module_get(btm->module)) |
| ret = btp; |
| goto out; |
| } |
| } |
| } |
| out: |
| mutex_unlock(&bpf_module_mutex); |
| return ret; |
| } |
| #else |
| static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) |
| { |
| return NULL; |
| } |
| #endif /* CONFIG_MODULES */ |
| |
| u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); |
| u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); |
| |
| /** |
| * trace_call_bpf - invoke BPF program |
| * @call: tracepoint event |
| * @ctx: opaque context pointer |
| * |
| * kprobe handlers execute BPF programs via this helper. |
| * Can be used from static tracepoints in the future. |
| * |
| * Return: BPF programs always return an integer which is interpreted by |
| * kprobe handler as: |
| * 0 - return from kprobe (event is filtered out) |
| * 1 - store kprobe event into ring buffer |
| * Other values are reserved and currently alias to 1 |
| */ |
| unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) |
| { |
| unsigned int ret; |
| |
| if (in_nmi()) /* not supported yet */ |
| return 1; |
| |
| preempt_disable(); |
| |
| if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { |
| /* |
| * since some bpf program is already running on this cpu, |
| * don't call into another bpf program (same or different) |
| * and don't send kprobe event into ring-buffer, |
| * so return zero here |
| */ |
| ret = 0; |
| goto out; |
| } |
| |
| /* |
| * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock |
| * to all call sites, we did a bpf_prog_array_valid() there to check |
| * whether call->prog_array is empty or not, which is |
| * a heurisitc to speed up execution. |
| * |
| * If bpf_prog_array_valid() fetched prog_array was |
| * non-NULL, we go into trace_call_bpf() and do the actual |
| * proper rcu_dereference() under RCU lock. |
| * If it turns out that prog_array is NULL then, we bail out. |
| * For the opposite, if the bpf_prog_array_valid() fetched pointer |
| * was NULL, you'll skip the prog_array with the risk of missing |
| * out of events when it was updated in between this and the |
| * rcu_dereference() which is accepted risk. |
| */ |
| ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN); |
| |
| out: |
| __this_cpu_dec(bpf_prog_active); |
| preempt_enable(); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(trace_call_bpf); |
| |
| #ifdef CONFIG_BPF_KPROBE_OVERRIDE |
| BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) |
| { |
| regs_set_return_value(regs, rc); |
| override_function_with_return(regs); |
| return 0; |
| } |
| |
| static const struct bpf_func_proto bpf_override_return_proto = { |
| .func = bpf_override_return, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_ANYTHING, |
| }; |
| #endif |
| |
| BPF_CALL_3(bpf_probe_read, void *, dst, u32, size, const void *, unsafe_ptr) |
| { |
| int ret; |
| |
| ret = probe_kernel_read(dst, unsafe_ptr, size); |
| if (unlikely(ret < 0)) |
| memset(dst, 0, size); |
| |
| return ret; |
| } |
| |
| static const struct bpf_func_proto bpf_probe_read_proto = { |
| .func = bpf_probe_read, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_3(bpf_probe_write_user, void *, unsafe_ptr, const void *, src, |
| u32, size) |
| { |
| /* |
| * Ensure we're in user context which is safe for the helper to |
| * run. This helper has no business in a kthread. |
| * |
| * access_ok() should prevent writing to non-user memory, but in |
| * some situations (nommu, temporary switch, etc) access_ok() does |
| * not provide enough validation, hence the check on KERNEL_DS. |
| */ |
| |
| if (unlikely(in_interrupt() || |
| current->flags & (PF_KTHREAD | PF_EXITING))) |
| return -EPERM; |
| if (unlikely(uaccess_kernel())) |
| return -EPERM; |
| if (!access_ok(unsafe_ptr, size)) |
| return -EPERM; |
| |
| return probe_kernel_write(unsafe_ptr, src, size); |
| } |
| |
| static const struct bpf_func_proto bpf_probe_write_user_proto = { |
| .func = bpf_probe_write_user, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_ANYTHING, |
| .arg2_type = ARG_PTR_TO_MEM, |
| .arg3_type = ARG_CONST_SIZE, |
| }; |
| |
| static const struct bpf_func_proto *bpf_get_probe_write_proto(void) |
| { |
| pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!", |
| current->comm, task_pid_nr(current)); |
| |
| return &bpf_probe_write_user_proto; |
| } |
| |
| /* |
| * Only limited trace_printk() conversion specifiers allowed: |
| * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %s |
| */ |
| BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, |
| u64, arg2, u64, arg3) |
| { |
| bool str_seen = false; |
| int mod[3] = {}; |
| int fmt_cnt = 0; |
| u64 unsafe_addr; |
| char buf[64]; |
| int i; |
| |
| /* |
| * bpf_check()->check_func_arg()->check_stack_boundary() |
| * guarantees that fmt points to bpf program stack, |
| * fmt_size bytes of it were initialized and fmt_size > 0 |
| */ |
| if (fmt[--fmt_size] != 0) |
| return -EINVAL; |
| |
| /* check format string for allowed specifiers */ |
| for (i = 0; i < fmt_size; i++) { |
| if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) |
| return -EINVAL; |
| |
| if (fmt[i] != '%') |
| continue; |
| |
| if (fmt_cnt >= 3) |
| return -EINVAL; |
| |
| /* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */ |
| i++; |
| if (fmt[i] == 'l') { |
| mod[fmt_cnt]++; |
| i++; |
| } else if (fmt[i] == 'p' || fmt[i] == 's') { |
| mod[fmt_cnt]++; |
| /* disallow any further format extensions */ |
| if (fmt[i + 1] != 0 && |
| !isspace(fmt[i + 1]) && |
| !ispunct(fmt[i + 1])) |
| return -EINVAL; |
| fmt_cnt++; |
| if (fmt[i] == 's') { |
| if (str_seen) |
| /* allow only one '%s' per fmt string */ |
| return -EINVAL; |
| str_seen = true; |
| |
| switch (fmt_cnt) { |
| case 1: |
| unsafe_addr = arg1; |
| arg1 = (long) buf; |
| break; |
| case 2: |
| unsafe_addr = arg2; |
| arg2 = (long) buf; |
| break; |
| case 3: |
| unsafe_addr = arg3; |
| arg3 = (long) buf; |
| break; |
| } |
| buf[0] = 0; |
| strncpy_from_unsafe(buf, |
| (void *) (long) unsafe_addr, |
| sizeof(buf)); |
| } |
| continue; |
| } |
| |
| if (fmt[i] == 'l') { |
| mod[fmt_cnt]++; |
| i++; |
| } |
| |
| if (fmt[i] != 'i' && fmt[i] != 'd' && |
| fmt[i] != 'u' && fmt[i] != 'x') |
| return -EINVAL; |
| fmt_cnt++; |
| } |
| |
| /* Horrid workaround for getting va_list handling working with different |
| * argument type combinations generically for 32 and 64 bit archs. |
| */ |
| #define __BPF_TP_EMIT() __BPF_ARG3_TP() |
| #define __BPF_TP(...) \ |
| __trace_printk(0 /* Fake ip */, \ |
| fmt, ##__VA_ARGS__) |
| |
| #define __BPF_ARG1_TP(...) \ |
| ((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64)) \ |
| ? __BPF_TP(arg1, ##__VA_ARGS__) \ |
| : ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32)) \ |
| ? __BPF_TP((long)arg1, ##__VA_ARGS__) \ |
| : __BPF_TP((u32)arg1, ##__VA_ARGS__))) |
| |
| #define __BPF_ARG2_TP(...) \ |
| ((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64)) \ |
| ? __BPF_ARG1_TP(arg2, ##__VA_ARGS__) \ |
| : ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32)) \ |
| ? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__) \ |
| : __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__))) |
| |
| #define __BPF_ARG3_TP(...) \ |
| ((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64)) \ |
| ? __BPF_ARG2_TP(arg3, ##__VA_ARGS__) \ |
| : ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32)) \ |
| ? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__) \ |
| : __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__))) |
| |
| return __BPF_TP_EMIT(); |
| } |
| |
| static const struct bpf_func_proto bpf_trace_printk_proto = { |
| .func = bpf_trace_printk, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_MEM, |
| .arg2_type = ARG_CONST_SIZE, |
| }; |
| |
| const struct bpf_func_proto *bpf_get_trace_printk_proto(void) |
| { |
| /* |
| * this program might be calling bpf_trace_printk, |
| * so allocate per-cpu printk buffers |
| */ |
| trace_printk_init_buffers(); |
| |
| return &bpf_trace_printk_proto; |
| } |
| |
| static __always_inline int |
| get_map_perf_counter(struct bpf_map *map, u64 flags, |
| u64 *value, u64 *enabled, u64 *running) |
| { |
| struct bpf_array *array = container_of(map, struct bpf_array, map); |
| unsigned int cpu = smp_processor_id(); |
| u64 index = flags & BPF_F_INDEX_MASK; |
| struct bpf_event_entry *ee; |
| |
| if (unlikely(flags & ~(BPF_F_INDEX_MASK))) |
| return -EINVAL; |
| if (index == BPF_F_CURRENT_CPU) |
| index = cpu; |
| if (unlikely(index >= array->map.max_entries)) |
| return -E2BIG; |
| |
| ee = READ_ONCE(array->ptrs[index]); |
| if (!ee) |
| return -ENOENT; |
| |
| return perf_event_read_local(ee->event, value, enabled, running); |
| } |
| |
| BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) |
| { |
| u64 value = 0; |
| int err; |
| |
| err = get_map_perf_counter(map, flags, &value, NULL, NULL); |
| /* |
| * this api is ugly since we miss [-22..-2] range of valid |
| * counter values, but that's uapi |
| */ |
| if (err) |
| return err; |
| return value; |
| } |
| |
| static const struct bpf_func_proto bpf_perf_event_read_proto = { |
| .func = bpf_perf_event_read, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, |
| struct bpf_perf_event_value *, buf, u32, size) |
| { |
| int err = -EINVAL; |
| |
| if (unlikely(size != sizeof(struct bpf_perf_event_value))) |
| goto clear; |
| err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, |
| &buf->running); |
| if (unlikely(err)) |
| goto clear; |
| return 0; |
| clear: |
| memset(buf, 0, size); |
| return err; |
| } |
| |
| static const struct bpf_func_proto bpf_perf_event_read_value_proto = { |
| .func = bpf_perf_event_read_value, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_ANYTHING, |
| .arg3_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg4_type = ARG_CONST_SIZE, |
| }; |
| |
| static DEFINE_PER_CPU(struct perf_sample_data, bpf_trace_sd); |
| |
| static __always_inline u64 |
| __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, |
| u64 flags, struct perf_sample_data *sd) |
| { |
| struct bpf_array *array = container_of(map, struct bpf_array, map); |
| unsigned int cpu = smp_processor_id(); |
| u64 index = flags & BPF_F_INDEX_MASK; |
| struct bpf_event_entry *ee; |
| struct perf_event *event; |
| |
| if (index == BPF_F_CURRENT_CPU) |
| index = cpu; |
| if (unlikely(index >= array->map.max_entries)) |
| return -E2BIG; |
| |
| ee = READ_ONCE(array->ptrs[index]); |
| if (!ee) |
| return -ENOENT; |
| |
| event = ee->event; |
| if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || |
| event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) |
| return -EINVAL; |
| |
| if (unlikely(event->oncpu != cpu)) |
| return -EOPNOTSUPP; |
| |
| return perf_event_output(event, sd, regs); |
| } |
| |
| BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, |
| u64, flags, void *, data, u64, size) |
| { |
| struct perf_sample_data *sd = this_cpu_ptr(&bpf_trace_sd); |
| struct perf_raw_record raw = { |
| .frag = { |
| .size = size, |
| .data = data, |
| }, |
| }; |
| |
| if (unlikely(flags & ~(BPF_F_INDEX_MASK))) |
| return -EINVAL; |
| |
| perf_sample_data_init(sd, 0, 0); |
| sd->raw = &raw; |
| |
| return __bpf_perf_event_output(regs, map, flags, sd); |
| } |
| |
| static const struct bpf_func_proto bpf_perf_event_output_proto = { |
| .func = bpf_perf_event_output, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| .arg4_type = ARG_PTR_TO_MEM, |
| .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| }; |
| |
| static DEFINE_PER_CPU(struct pt_regs, bpf_pt_regs); |
| static DEFINE_PER_CPU(struct perf_sample_data, bpf_misc_sd); |
| |
| u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, |
| void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) |
| { |
| struct perf_sample_data *sd = this_cpu_ptr(&bpf_misc_sd); |
| struct pt_regs *regs = this_cpu_ptr(&bpf_pt_regs); |
| struct perf_raw_frag frag = { |
| .copy = ctx_copy, |
| .size = ctx_size, |
| .data = ctx, |
| }; |
| struct perf_raw_record raw = { |
| .frag = { |
| { |
| .next = ctx_size ? &frag : NULL, |
| }, |
| .size = meta_size, |
| .data = meta, |
| }, |
| }; |
| |
| perf_fetch_caller_regs(regs); |
| perf_sample_data_init(sd, 0, 0); |
| sd->raw = &raw; |
| |
| return __bpf_perf_event_output(regs, map, flags, sd); |
| } |
| |
| BPF_CALL_0(bpf_get_current_task) |
| { |
| return (long) current; |
| } |
| |
| static const struct bpf_func_proto bpf_get_current_task_proto = { |
| .func = bpf_get_current_task, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| }; |
| |
| BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) |
| { |
| struct bpf_array *array = container_of(map, struct bpf_array, map); |
| struct cgroup *cgrp; |
| |
| if (unlikely(idx >= array->map.max_entries)) |
| return -E2BIG; |
| |
| cgrp = READ_ONCE(array->ptrs[idx]); |
| if (unlikely(!cgrp)) |
| return -EAGAIN; |
| |
| return task_under_cgroup_hierarchy(current, cgrp); |
| } |
| |
| static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { |
| .func = bpf_current_task_under_cgroup, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_3(bpf_probe_read_str, void *, dst, u32, size, |
| const void *, unsafe_ptr) |
| { |
| int ret; |
| |
| /* |
| * The strncpy_from_unsafe() call will likely not fill the entire |
| * buffer, but that's okay in this circumstance as we're probing |
| * arbitrary memory anyway similar to bpf_probe_read() and might |
| * as well probe the stack. Thus, memory is explicitly cleared |
| * only in error case, so that improper users ignoring return |
| * code altogether don't copy garbage; otherwise length of string |
| * is returned that can be used for bpf_perf_event_output() et al. |
| */ |
| ret = strncpy_from_unsafe(dst, unsafe_ptr, size); |
| if (unlikely(ret < 0)) |
| memset(dst, 0, size); |
| |
| return ret; |
| } |
| |
| static const struct bpf_func_proto bpf_probe_read_str_proto = { |
| .func = bpf_probe_read_str, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| static const struct bpf_func_proto * |
| tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| { |
| switch (func_id) { |
| case BPF_FUNC_map_lookup_elem: |
| return &bpf_map_lookup_elem_proto; |
| case BPF_FUNC_map_update_elem: |
| return &bpf_map_update_elem_proto; |
| case BPF_FUNC_map_delete_elem: |
| return &bpf_map_delete_elem_proto; |
| case BPF_FUNC_map_push_elem: |
| return &bpf_map_push_elem_proto; |
| case BPF_FUNC_map_pop_elem: |
| return &bpf_map_pop_elem_proto; |
| case BPF_FUNC_map_peek_elem: |
| return &bpf_map_peek_elem_proto; |
| case BPF_FUNC_probe_read: |
| return &bpf_probe_read_proto; |
| case BPF_FUNC_ktime_get_ns: |
| return &bpf_ktime_get_ns_proto; |
| case BPF_FUNC_tail_call: |
| return &bpf_tail_call_proto; |
| case BPF_FUNC_get_current_pid_tgid: |
| return &bpf_get_current_pid_tgid_proto; |
| case BPF_FUNC_get_current_task: |
| return &bpf_get_current_task_proto; |
| case BPF_FUNC_get_current_uid_gid: |
| return &bpf_get_current_uid_gid_proto; |
| case BPF_FUNC_get_current_comm: |
| return &bpf_get_current_comm_proto; |
| case BPF_FUNC_trace_printk: |
| return bpf_get_trace_printk_proto(); |
| case BPF_FUNC_get_smp_processor_id: |
| return &bpf_get_smp_processor_id_proto; |
| case BPF_FUNC_get_numa_node_id: |
| return &bpf_get_numa_node_id_proto; |
| case BPF_FUNC_perf_event_read: |
| return &bpf_perf_event_read_proto; |
| case BPF_FUNC_probe_write_user: |
| return bpf_get_probe_write_proto(); |
| case BPF_FUNC_current_task_under_cgroup: |
| return &bpf_current_task_under_cgroup_proto; |
| case BPF_FUNC_get_prandom_u32: |
| return &bpf_get_prandom_u32_proto; |
| case BPF_FUNC_probe_read_str: |
| return &bpf_probe_read_str_proto; |
| #ifdef CONFIG_CGROUPS |
| case BPF_FUNC_get_current_cgroup_id: |
| return &bpf_get_current_cgroup_id_proto; |
| #endif |
| default: |
| return NULL; |
| } |
| } |
| |
| static const struct bpf_func_proto * |
| kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| { |
| switch (func_id) { |
| case BPF_FUNC_perf_event_output: |
| return &bpf_perf_event_output_proto; |
| case BPF_FUNC_get_stackid: |
| return &bpf_get_stackid_proto; |
| case BPF_FUNC_get_stack: |
| return &bpf_get_stack_proto; |
| case BPF_FUNC_perf_event_read_value: |
| return &bpf_perf_event_read_value_proto; |
| #ifdef CONFIG_BPF_KPROBE_OVERRIDE |
| case BPF_FUNC_override_return: |
| return &bpf_override_return_proto; |
| #endif |
| default: |
| return tracing_func_proto(func_id, prog); |
| } |
| } |
| |
| /* bpf+kprobe programs can access fields of 'struct pt_regs' */ |
| static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
| const struct bpf_prog *prog, |
| struct bpf_insn_access_aux *info) |
| { |
| if (off < 0 || off >= sizeof(struct pt_regs)) |
| return false; |
| if (type != BPF_READ) |
| return false; |
| if (off % size != 0) |
| return false; |
| /* |
| * Assertion for 32 bit to make sure last 8 byte access |
| * (BPF_DW) to the last 4 byte member is disallowed. |
| */ |
| if (off + size > sizeof(struct pt_regs)) |
| return false; |
| |
| return true; |
| } |
| |
| const struct bpf_verifier_ops kprobe_verifier_ops = { |
| .get_func_proto = kprobe_prog_func_proto, |
| .is_valid_access = kprobe_prog_is_valid_access, |
| }; |
| |
| const struct bpf_prog_ops kprobe_prog_ops = { |
| }; |
| |
| BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, |
| u64, flags, void *, data, u64, size) |
| { |
| struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
| |
| /* |
| * r1 points to perf tracepoint buffer where first 8 bytes are hidden |
| * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it |
| * from there and call the same bpf_perf_event_output() helper inline. |
| */ |
| return ____bpf_perf_event_output(regs, map, flags, data, size); |
| } |
| |
| static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { |
| .func = bpf_perf_event_output_tp, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| .arg4_type = ARG_PTR_TO_MEM, |
| .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| }; |
| |
| BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, |
| u64, flags) |
| { |
| struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
| |
| /* |
| * Same comment as in bpf_perf_event_output_tp(), only that this time |
| * the other helper's function body cannot be inlined due to being |
| * external, thus we need to call raw helper function. |
| */ |
| return bpf_get_stackid((unsigned long) regs, (unsigned long) map, |
| flags, 0, 0); |
| } |
| |
| static const struct bpf_func_proto bpf_get_stackid_proto_tp = { |
| .func = bpf_get_stackid_tp, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, |
| u64, flags) |
| { |
| struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
| |
| return bpf_get_stack((unsigned long) regs, (unsigned long) buf, |
| (unsigned long) size, flags, 0); |
| } |
| |
| static const struct bpf_func_proto bpf_get_stack_proto_tp = { |
| .func = bpf_get_stack_tp, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| static const struct bpf_func_proto * |
| tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| { |
| switch (func_id) { |
| case BPF_FUNC_perf_event_output: |
| return &bpf_perf_event_output_proto_tp; |
| case BPF_FUNC_get_stackid: |
| return &bpf_get_stackid_proto_tp; |
| case BPF_FUNC_get_stack: |
| return &bpf_get_stack_proto_tp; |
| default: |
| return tracing_func_proto(func_id, prog); |
| } |
| } |
| |
| static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
| const struct bpf_prog *prog, |
| struct bpf_insn_access_aux *info) |
| { |
| if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) |
| return false; |
| if (type != BPF_READ) |
| return false; |
| if (off % size != 0) |
| return false; |
| |
| BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); |
| return true; |
| } |
| |
| const struct bpf_verifier_ops tracepoint_verifier_ops = { |
| .get_func_proto = tp_prog_func_proto, |
| .is_valid_access = tp_prog_is_valid_access, |
| }; |
| |
| const struct bpf_prog_ops tracepoint_prog_ops = { |
| }; |
| |
| BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, |
| struct bpf_perf_event_value *, buf, u32, size) |
| { |
| int err = -EINVAL; |
| |
| if (unlikely(size != sizeof(struct bpf_perf_event_value))) |
| goto clear; |
| err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, |
| &buf->running); |
| if (unlikely(err)) |
| goto clear; |
| return 0; |
| clear: |
| memset(buf, 0, size); |
| return err; |
| } |
| |
| static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { |
| .func = bpf_perf_prog_read_value, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg3_type = ARG_CONST_SIZE, |
| }; |
| |
| static const struct bpf_func_proto * |
| pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| { |
| switch (func_id) { |
| case BPF_FUNC_perf_event_output: |
| return &bpf_perf_event_output_proto_tp; |
| case BPF_FUNC_get_stackid: |
| return &bpf_get_stackid_proto_tp; |
| case BPF_FUNC_get_stack: |
| return &bpf_get_stack_proto_tp; |
| case BPF_FUNC_perf_prog_read_value: |
| return &bpf_perf_prog_read_value_proto; |
| default: |
| return tracing_func_proto(func_id, prog); |
| } |
| } |
| |
| /* |
| * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp |
| * to avoid potential recursive reuse issue when/if tracepoints are added |
| * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack |
| */ |
| static DEFINE_PER_CPU(struct pt_regs, bpf_raw_tp_regs); |
| BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, |
| struct bpf_map *, map, u64, flags, void *, data, u64, size) |
| { |
| struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs); |
| |
| perf_fetch_caller_regs(regs); |
| return ____bpf_perf_event_output(regs, map, flags, data, size); |
| } |
| |
| static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { |
| .func = bpf_perf_event_output_raw_tp, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| .arg4_type = ARG_PTR_TO_MEM, |
| .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| }; |
| |
| BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, |
| struct bpf_map *, map, u64, flags) |
| { |
| struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs); |
| |
| perf_fetch_caller_regs(regs); |
| /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ |
| return bpf_get_stackid((unsigned long) regs, (unsigned long) map, |
| flags, 0, 0); |
| } |
| |
| static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { |
| .func = bpf_get_stackid_raw_tp, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, |
| void *, buf, u32, size, u64, flags) |
| { |
| struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs); |
| |
| perf_fetch_caller_regs(regs); |
| return bpf_get_stack((unsigned long) regs, (unsigned long) buf, |
| (unsigned long) size, flags, 0); |
| } |
| |
| static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { |
| .func = bpf_get_stack_raw_tp, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_PTR_TO_MEM, |
| .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| static const struct bpf_func_proto * |
| raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| { |
| switch (func_id) { |
| case BPF_FUNC_perf_event_output: |
| return &bpf_perf_event_output_proto_raw_tp; |
| case BPF_FUNC_get_stackid: |
| return &bpf_get_stackid_proto_raw_tp; |
| case BPF_FUNC_get_stack: |
| return &bpf_get_stack_proto_raw_tp; |
| default: |
| return tracing_func_proto(func_id, prog); |
| } |
| } |
| |
| static bool raw_tp_prog_is_valid_access(int off, int size, |
| enum bpf_access_type type, |
| const struct bpf_prog *prog, |
| struct bpf_insn_access_aux *info) |
| { |
| /* largest tracepoint in the kernel has 12 args */ |
| if (off < 0 || off >= sizeof(__u64) * 12) |
| return false; |
| if (type != BPF_READ) |
| return false; |
| if (off % size != 0) |
| return false; |
| return true; |
| } |
| |
| const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { |
| .get_func_proto = raw_tp_prog_func_proto, |
| .is_valid_access = raw_tp_prog_is_valid_access, |
| }; |
| |
| const struct bpf_prog_ops raw_tracepoint_prog_ops = { |
| }; |
| |
| static bool raw_tp_writable_prog_is_valid_access(int off, int size, |
| enum bpf_access_type type, |
| const struct bpf_prog *prog, |
| struct bpf_insn_access_aux *info) |
| { |
| if (off == 0) { |
| if (size != sizeof(u64) || type != BPF_READ) |
| return false; |
| info->reg_type = PTR_TO_TP_BUFFER; |
| } |
| return raw_tp_prog_is_valid_access(off, size, type, prog, info); |
| } |
| |
| const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { |
| .get_func_proto = raw_tp_prog_func_proto, |
| .is_valid_access = raw_tp_writable_prog_is_valid_access, |
| }; |
| |
| const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { |
| }; |
| |
| static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
| const struct bpf_prog *prog, |
| struct bpf_insn_access_aux *info) |
| { |
| const int size_u64 = sizeof(u64); |
| |
| if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) |
| return false; |
| if (type != BPF_READ) |
| return false; |
| if (off % size != 0) { |
| if (sizeof(unsigned long) != 4) |
| return false; |
| if (size != 8) |
| return false; |
| if (off % size != 4) |
| return false; |
| } |
| |
| switch (off) { |
| case bpf_ctx_range(struct bpf_perf_event_data, sample_period): |
| bpf_ctx_record_field_size(info, size_u64); |
| if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) |
| return false; |
| break; |
| case bpf_ctx_range(struct bpf_perf_event_data, addr): |
| bpf_ctx_record_field_size(info, size_u64); |
| if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) |
| return false; |
| break; |
| default: |
| if (size != sizeof(long)) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, |
| const struct bpf_insn *si, |
| struct bpf_insn *insn_buf, |
| struct bpf_prog *prog, u32 *target_size) |
| { |
| struct bpf_insn *insn = insn_buf; |
| |
| switch (si->off) { |
| case offsetof(struct bpf_perf_event_data, sample_period): |
| *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
| data), si->dst_reg, si->src_reg, |
| offsetof(struct bpf_perf_event_data_kern, data)); |
| *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, |
| bpf_target_off(struct perf_sample_data, period, 8, |
| target_size)); |
| break; |
| case offsetof(struct bpf_perf_event_data, addr): |
| *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
| data), si->dst_reg, si->src_reg, |
| offsetof(struct bpf_perf_event_data_kern, data)); |
| *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, |
| bpf_target_off(struct perf_sample_data, addr, 8, |
| target_size)); |
| break; |
| default: |
| *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
| regs), si->dst_reg, si->src_reg, |
| offsetof(struct bpf_perf_event_data_kern, regs)); |
| *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, |
| si->off); |
| break; |
| } |
| |
| return insn - insn_buf; |
| } |
| |
| const struct bpf_verifier_ops perf_event_verifier_ops = { |
| .get_func_proto = pe_prog_func_proto, |
| .is_valid_access = pe_prog_is_valid_access, |
| .convert_ctx_access = pe_prog_convert_ctx_access, |
| }; |
| |
| const struct bpf_prog_ops perf_event_prog_ops = { |
| }; |
| |
| static DEFINE_MUTEX(bpf_event_mutex); |
| |
| #define BPF_TRACE_MAX_PROGS 64 |
| |
| int perf_event_attach_bpf_prog(struct perf_event *event, |
| struct bpf_prog *prog) |
| { |
| struct bpf_prog_array __rcu *old_array; |
| struct bpf_prog_array *new_array; |
| int ret = -EEXIST; |
| |
| /* |
| * Kprobe override only works if they are on the function entry, |
| * and only if they are on the opt-in list. |
| */ |
| if (prog->kprobe_override && |
| (!trace_kprobe_on_func_entry(event->tp_event) || |
| !trace_kprobe_error_injectable(event->tp_event))) |
| return -EINVAL; |
| |
| mutex_lock(&bpf_event_mutex); |
| |
| if (event->prog) |
| goto unlock; |
| |
| old_array = event->tp_event->prog_array; |
| if (old_array && |
| bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { |
| ret = -E2BIG; |
| goto unlock; |
| } |
| |
| ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array); |
| if (ret < 0) |
| goto unlock; |
| |
| /* set the new array to event->tp_event and set event->prog */ |
| event->prog = prog; |
| rcu_assign_pointer(event->tp_event->prog_array, new_array); |
| bpf_prog_array_free(old_array); |
| |
| unlock: |
| mutex_unlock(&bpf_event_mutex); |
| return ret; |
| } |
| |
| void perf_event_detach_bpf_prog(struct perf_event *event) |
| { |
| struct bpf_prog_array __rcu *old_array; |
| struct bpf_prog_array *new_array; |
| int ret; |
| |
| mutex_lock(&bpf_event_mutex); |
| |
| if (!event->prog) |
| goto unlock; |
| |
| old_array = event->tp_event->prog_array; |
| ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array); |
| if (ret == -ENOENT) |
| goto unlock; |
| if (ret < 0) { |
| bpf_prog_array_delete_safe(old_array, event->prog); |
| } else { |
| rcu_assign_pointer(event->tp_event->prog_array, new_array); |
| bpf_prog_array_free(old_array); |
| } |
| |
| bpf_prog_put(event->prog); |
| event->prog = NULL; |
| |
| unlock: |
| mutex_unlock(&bpf_event_mutex); |
| } |
| |
| int perf_event_query_prog_array(struct perf_event *event, void __user *info) |
| { |
| struct perf_event_query_bpf __user *uquery = info; |
| struct perf_event_query_bpf query = {}; |
| u32 *ids, prog_cnt, ids_len; |
| int ret; |
| |
| if (!capable(CAP_SYS_ADMIN)) |
| return -EPERM; |
| if (event->attr.type != PERF_TYPE_TRACEPOINT) |
| return -EINVAL; |
| if (copy_from_user(&query, uquery, sizeof(query))) |
| return -EFAULT; |
| |
| ids_len = query.ids_len; |
| if (ids_len > BPF_TRACE_MAX_PROGS) |
| return -E2BIG; |
| ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); |
| if (!ids) |
| return -ENOMEM; |
| /* |
| * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which |
| * is required when user only wants to check for uquery->prog_cnt. |
| * There is no need to check for it since the case is handled |
| * gracefully in bpf_prog_array_copy_info. |
| */ |
| |
| mutex_lock(&bpf_event_mutex); |
| ret = bpf_prog_array_copy_info(event->tp_event->prog_array, |
| ids, |
| ids_len, |
| &prog_cnt); |
| mutex_unlock(&bpf_event_mutex); |
| |
| if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || |
| copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) |
| ret = -EFAULT; |
| |
| kfree(ids); |
| return ret; |
| } |
| |
| extern struct bpf_raw_event_map __start__bpf_raw_tp[]; |
| extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; |
| |
| struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) |
| { |
| struct bpf_raw_event_map *btp = __start__bpf_raw_tp; |
| |
| for (; btp < __stop__bpf_raw_tp; btp++) { |
| if (!strcmp(btp->tp->name, name)) |
| return btp; |
| } |
| |
| return bpf_get_raw_tracepoint_module(name); |
| } |
| |
| void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) |
| { |
| struct module *mod = __module_address((unsigned long)btp); |
| |
| if (mod) |
| module_put(mod); |
| } |
| |
| static __always_inline |
| void __bpf_trace_run(struct bpf_prog *prog, u64 *args) |
| { |
| rcu_read_lock(); |
| preempt_disable(); |
| (void) BPF_PROG_RUN(prog, args); |
| preempt_enable(); |
| rcu_read_unlock(); |
| } |
| |
| #define UNPACK(...) __VA_ARGS__ |
| #define REPEAT_1(FN, DL, X, ...) FN(X) |
| #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) |
| #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) |
| #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) |
| #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) |
| #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) |
| #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) |
| #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) |
| #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) |
| #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) |
| #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) |
| #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) |
| #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) |
| |
| #define SARG(X) u64 arg##X |
| #define COPY(X) args[X] = arg##X |
| |
| #define __DL_COM (,) |
| #define __DL_SEM (;) |
| |
| #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 |
| |
| #define BPF_TRACE_DEFN_x(x) \ |
| void bpf_trace_run##x(struct bpf_prog *prog, \ |
| REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ |
| { \ |
| u64 args[x]; \ |
| REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ |
| __bpf_trace_run(prog, args); \ |
| } \ |
| EXPORT_SYMBOL_GPL(bpf_trace_run##x) |
| BPF_TRACE_DEFN_x(1); |
| BPF_TRACE_DEFN_x(2); |
| BPF_TRACE_DEFN_x(3); |
| BPF_TRACE_DEFN_x(4); |
| BPF_TRACE_DEFN_x(5); |
| BPF_TRACE_DEFN_x(6); |
| BPF_TRACE_DEFN_x(7); |
| BPF_TRACE_DEFN_x(8); |
| BPF_TRACE_DEFN_x(9); |
| BPF_TRACE_DEFN_x(10); |
| BPF_TRACE_DEFN_x(11); |
| BPF_TRACE_DEFN_x(12); |
| |
| static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) |
| { |
| struct tracepoint *tp = btp->tp; |
| |
| /* |
| * check that program doesn't access arguments beyond what's |
| * available in this tracepoint |
| */ |
| if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) |
| return -EINVAL; |
| |
| if (prog->aux->max_tp_access > btp->writable_size) |
| return -EINVAL; |
| |
| return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog); |
| } |
| |
| int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) |
| { |
| return __bpf_probe_register(btp, prog); |
| } |
| |
| int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) |
| { |
| return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); |
| } |
| |
| int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, |
| u32 *fd_type, const char **buf, |
| u64 *probe_offset, u64 *probe_addr) |
| { |
| bool is_tracepoint, is_syscall_tp; |
| struct bpf_prog *prog; |
| int flags, err = 0; |
| |
| prog = event->prog; |
| if (!prog) |
| return -ENOENT; |
| |
| /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ |
| if (prog->type == BPF_PROG_TYPE_PERF_EVENT) |
| return -EOPNOTSUPP; |
| |
| *prog_id = prog->aux->id; |
| flags = event->tp_event->flags; |
| is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; |
| is_syscall_tp = is_syscall_trace_event(event->tp_event); |
| |
| if (is_tracepoint || is_syscall_tp) { |
| *buf = is_tracepoint ? event->tp_event->tp->name |
| : event->tp_event->name; |
| *fd_type = BPF_FD_TYPE_TRACEPOINT; |
| *probe_offset = 0x0; |
| *probe_addr = 0x0; |
| } else { |
| /* kprobe/uprobe */ |
| err = -EOPNOTSUPP; |
| #ifdef CONFIG_KPROBE_EVENTS |
| if (flags & TRACE_EVENT_FL_KPROBE) |
| err = bpf_get_kprobe_info(event, fd_type, buf, |
| probe_offset, probe_addr, |
| event->attr.type == PERF_TYPE_TRACEPOINT); |
| #endif |
| #ifdef CONFIG_UPROBE_EVENTS |
| if (flags & TRACE_EVENT_FL_UPROBE) |
| err = bpf_get_uprobe_info(event, fd_type, buf, |
| probe_offset, |
| event->attr.type == PERF_TYPE_TRACEPOINT); |
| #endif |
| } |
| |
| return err; |
| } |
| |
| #ifdef CONFIG_MODULES |
| int bpf_event_notify(struct notifier_block *nb, unsigned long op, void *module) |
| { |
| struct bpf_trace_module *btm, *tmp; |
| struct module *mod = module; |
| |
| if (mod->num_bpf_raw_events == 0 || |
| (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) |
| return 0; |
| |
| mutex_lock(&bpf_module_mutex); |
| |
| switch (op) { |
| case MODULE_STATE_COMING: |
| btm = kzalloc(sizeof(*btm), GFP_KERNEL); |
| if (btm) { |
| btm->module = module; |
| list_add(&btm->list, &bpf_trace_modules); |
| } |
| break; |
| case MODULE_STATE_GOING: |
| list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { |
| if (btm->module == module) { |
| list_del(&btm->list); |
| kfree(btm); |
| break; |
| } |
| } |
| break; |
| } |
| |
| mutex_unlock(&bpf_module_mutex); |
| |
| return 0; |
| } |
| |
| static struct notifier_block bpf_module_nb = { |
| .notifier_call = bpf_event_notify, |
| }; |
| |
| int __init bpf_event_init(void) |
| { |
| register_module_notifier(&bpf_module_nb); |
| return 0; |
| } |
| |
| fs_initcall(bpf_event_init); |
| #endif /* CONFIG_MODULES */ |