| // 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/btf.h> | |
| #include <linux/filter.h> | |
| #include <linux/uaccess.h> | |
| #include <linux/ctype.h> | |
| #include <linux/kprobes.h> | |
| #include <linux/spinlock.h> | |
| #include <linux/syscalls.h> | |
| #include <linux/error-injection.h> | |
| #include <linux/btf_ids.h> | |
| #include <uapi/linux/bpf.h> | |
| #include <uapi/linux/btf.h> | |
| #include <asm/tlb.h> | |
| #include "trace_probe.h" | |
| #include "trace.h" | |
| #define CREATE_TRACE_POINTS | |
| #include "bpf_trace.h" | |
| #define bpf_event_rcu_dereference(p) \ | |
| rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) | |
| #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); | |
| static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, | |
| u64 flags, const struct btf **btf, | |
| s32 *btf_id); | |
| /** | |
| * 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; | |
| cant_sleep(); | |
| 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); | |
| return ret; | |
| } | |
| #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 | |
| static __always_inline int | |
| bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) | |
| { | |
| int ret; | |
| ret = copy_from_user_nofault(dst, unsafe_ptr, size); | |
| if (unlikely(ret < 0)) | |
| memset(dst, 0, size); | |
| return ret; | |
| } | |
| BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, | |
| const void __user *, unsafe_ptr) | |
| { | |
| return bpf_probe_read_user_common(dst, size, unsafe_ptr); | |
| } | |
| const struct bpf_func_proto bpf_probe_read_user_proto = { | |
| .func = bpf_probe_read_user, | |
| .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 __always_inline int | |
| bpf_probe_read_user_str_common(void *dst, u32 size, | |
| const void __user *unsafe_ptr) | |
| { | |
| int ret; | |
| ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); | |
| if (unlikely(ret < 0)) | |
| memset(dst, 0, size); | |
| return ret; | |
| } | |
| BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, | |
| const void __user *, unsafe_ptr) | |
| { | |
| return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); | |
| } | |
| const struct bpf_func_proto bpf_probe_read_user_str_proto = { | |
| .func = bpf_probe_read_user_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 __always_inline int | |
| bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr) | |
| { | |
| int ret = security_locked_down(LOCKDOWN_BPF_READ); | |
| if (unlikely(ret < 0)) | |
| goto fail; | |
| ret = copy_from_kernel_nofault(dst, unsafe_ptr, size); | |
| if (unlikely(ret < 0)) | |
| goto fail; | |
| return ret; | |
| fail: | |
| memset(dst, 0, size); | |
| return ret; | |
| } | |
| BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, | |
| const void *, unsafe_ptr) | |
| { | |
| return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); | |
| } | |
| const struct bpf_func_proto bpf_probe_read_kernel_proto = { | |
| .func = bpf_probe_read_kernel, | |
| .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 __always_inline int | |
| bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) | |
| { | |
| int ret = security_locked_down(LOCKDOWN_BPF_READ); | |
| if (unlikely(ret < 0)) | |
| goto fail; | |
| /* | |
| * The strncpy_from_kernel_nofault() 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_kernel_nofault(dst, unsafe_ptr, size); | |
| if (unlikely(ret < 0)) | |
| goto fail; | |
| return ret; | |
| fail: | |
| memset(dst, 0, size); | |
| return ret; | |
| } | |
| BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, | |
| const void *, unsafe_ptr) | |
| { | |
| return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); | |
| } | |
| const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { | |
| .func = bpf_probe_read_kernel_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, | |
| }; | |
| #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE | |
| BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, | |
| const void *, unsafe_ptr) | |
| { | |
| if ((unsigned long)unsafe_ptr < TASK_SIZE) { | |
| return bpf_probe_read_user_common(dst, size, | |
| (__force void __user *)unsafe_ptr); | |
| } | |
| return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); | |
| } | |
| static const struct bpf_func_proto bpf_probe_read_compat_proto = { | |
| .func = bpf_probe_read_compat, | |
| .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_read_compat_str, void *, dst, u32, size, | |
| const void *, unsafe_ptr) | |
| { | |
| if ((unsigned long)unsafe_ptr < TASK_SIZE) { | |
| return bpf_probe_read_user_str_common(dst, size, | |
| (__force void __user *)unsafe_ptr); | |
| } | |
| return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); | |
| } | |
| static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { | |
| .func = bpf_probe_read_compat_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, | |
| }; | |
| #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ | |
| BPF_CALL_3(bpf_probe_write_user, void __user *, 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. | |
| * | |
| * nmi_uaccess_okay() ensures the probe is not run in an interim | |
| * state, when the task or mm are switched. This is specifically | |
| * required to prevent the use of temporary mm. | |
| */ | |
| if (unlikely(in_interrupt() || | |
| current->flags & (PF_KTHREAD | PF_EXITING))) | |
| return -EPERM; | |
| if (unlikely(uaccess_kernel())) | |
| return -EPERM; | |
| if (unlikely(!nmi_uaccess_okay())) | |
| return -EPERM; | |
| return copy_to_user_nofault(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) | |
| { | |
| if (!capable(CAP_SYS_ADMIN)) | |
| return NULL; | |
| 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; | |
| } | |
| static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype, | |
| size_t bufsz) | |
| { | |
| void __user *user_ptr = (__force void __user *)unsafe_ptr; | |
| buf[0] = 0; | |
| switch (fmt_ptype) { | |
| case 's': | |
| #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE | |
| if ((unsigned long)unsafe_ptr < TASK_SIZE) { | |
| strncpy_from_user_nofault(buf, user_ptr, bufsz); | |
| break; | |
| } | |
| fallthrough; | |
| #endif | |
| case 'k': | |
| strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz); | |
| break; | |
| case 'u': | |
| strncpy_from_user_nofault(buf, user_ptr, bufsz); | |
| break; | |
| } | |
| } | |
| static DEFINE_RAW_SPINLOCK(trace_printk_lock); | |
| #define BPF_TRACE_PRINTK_SIZE 1024 | |
| static __printf(1, 0) int bpf_do_trace_printk(const char *fmt, ...) | |
| { | |
| static char buf[BPF_TRACE_PRINTK_SIZE]; | |
| unsigned long flags; | |
| va_list ap; | |
| int ret; | |
| raw_spin_lock_irqsave(&trace_printk_lock, flags); | |
| va_start(ap, fmt); | |
| ret = vsnprintf(buf, sizeof(buf), fmt, ap); | |
| va_end(ap); | |
| /* vsnprintf() will not append null for zero-length strings */ | |
| if (ret == 0) | |
| buf[0] = '\0'; | |
| trace_bpf_trace_printk(buf); | |
| raw_spin_unlock_irqrestore(&trace_printk_lock, flags); | |
| return ret; | |
| } | |
| /* | |
| * Only limited trace_printk() conversion specifiers allowed: | |
| * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pB %pks %pus %s | |
| */ | |
| BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, | |
| u64, arg2, u64, arg3) | |
| { | |
| int i, mod[3] = {}, fmt_cnt = 0; | |
| char buf[64], fmt_ptype; | |
| void *unsafe_ptr = NULL; | |
| bool str_seen = false; | |
| /* | |
| * 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') { | |
| mod[fmt_cnt]++; | |
| if ((fmt[i + 1] == 'k' || | |
| fmt[i + 1] == 'u') && | |
| fmt[i + 2] == 's') { | |
| fmt_ptype = fmt[i + 1]; | |
| i += 2; | |
| goto fmt_str; | |
| } | |
| if (fmt[i + 1] == 'B') { | |
| i++; | |
| goto fmt_next; | |
| } | |
| /* disallow any further format extensions */ | |
| if (fmt[i + 1] != 0 && | |
| !isspace(fmt[i + 1]) && | |
| !ispunct(fmt[i + 1])) | |
| return -EINVAL; | |
| goto fmt_next; | |
| } else if (fmt[i] == 's') { | |
| mod[fmt_cnt]++; | |
| fmt_ptype = fmt[i]; | |
| fmt_str: | |
| if (str_seen) | |
| /* allow only one '%s' per fmt string */ | |
| return -EINVAL; | |
| str_seen = true; | |
| if (fmt[i + 1] != 0 && | |
| !isspace(fmt[i + 1]) && | |
| !ispunct(fmt[i + 1])) | |
| return -EINVAL; | |
| switch (fmt_cnt) { | |
| case 0: | |
| unsafe_ptr = (void *)(long)arg1; | |
| arg1 = (long)buf; | |
| break; | |
| case 1: | |
| unsafe_ptr = (void *)(long)arg2; | |
| arg2 = (long)buf; | |
| break; | |
| case 2: | |
| unsafe_ptr = (void *)(long)arg3; | |
| arg3 = (long)buf; | |
| break; | |
| } | |
| bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype, | |
| sizeof(buf)); | |
| goto fmt_next; | |
| } | |
| if (fmt[i] == 'l') { | |
| mod[fmt_cnt]++; | |
| i++; | |
| } | |
| if (fmt[i] != 'i' && fmt[i] != 'd' && | |
| fmt[i] != 'u' && fmt[i] != 'x') | |
| return -EINVAL; | |
| fmt_next: | |
| 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(...) \ | |
| bpf_do_trace_printk(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 enable the associated bpf_trace/bpf_trace_printk event. | |
| * Repeat this each time as it is possible a user has | |
| * disabled bpf_trace_printk events. By loading a program | |
| * calling bpf_trace_printk() however the user has expressed | |
| * the intent to see such events. | |
| */ | |
| if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) | |
| pr_warn_ratelimited("could not enable bpf_trace_printk events"); | |
| return &bpf_trace_printk_proto; | |
| } | |
| #define MAX_SEQ_PRINTF_VARARGS 12 | |
| #define MAX_SEQ_PRINTF_MAX_MEMCPY 6 | |
| #define MAX_SEQ_PRINTF_STR_LEN 128 | |
| struct bpf_seq_printf_buf { | |
| char buf[MAX_SEQ_PRINTF_MAX_MEMCPY][MAX_SEQ_PRINTF_STR_LEN]; | |
| }; | |
| static DEFINE_PER_CPU(struct bpf_seq_printf_buf, bpf_seq_printf_buf); | |
| static DEFINE_PER_CPU(int, bpf_seq_printf_buf_used); | |
| BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, | |
| const void *, data, u32, data_len) | |
| { | |
| int err = -EINVAL, fmt_cnt = 0, memcpy_cnt = 0; | |
| int i, buf_used, copy_size, num_args; | |
| u64 params[MAX_SEQ_PRINTF_VARARGS]; | |
| struct bpf_seq_printf_buf *bufs; | |
| const u64 *args = data; | |
| buf_used = this_cpu_inc_return(bpf_seq_printf_buf_used); | |
| if (WARN_ON_ONCE(buf_used > 1)) { | |
| err = -EBUSY; | |
| goto out; | |
| } | |
| bufs = this_cpu_ptr(&bpf_seq_printf_buf); | |
| /* | |
| * 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) | |
| goto out; | |
| if (data_len & 7) | |
| goto out; | |
| for (i = 0; i < fmt_size; i++) { | |
| if (fmt[i] == '%') { | |
| if (fmt[i + 1] == '%') | |
| i++; | |
| else if (!data || !data_len) | |
| goto out; | |
| } | |
| } | |
| num_args = data_len / 8; | |
| /* check format string for allowed specifiers */ | |
| for (i = 0; i < fmt_size; i++) { | |
| /* only printable ascii for now. */ | |
| if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) { | |
| err = -EINVAL; | |
| goto out; | |
| } | |
| if (fmt[i] != '%') | |
| continue; | |
| if (fmt[i + 1] == '%') { | |
| i++; | |
| continue; | |
| } | |
| if (fmt_cnt >= MAX_SEQ_PRINTF_VARARGS) { | |
| err = -E2BIG; | |
| goto out; | |
| } | |
| if (fmt_cnt >= num_args) { | |
| err = -EINVAL; | |
| goto out; | |
| } | |
| /* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */ | |
| i++; | |
| /* skip optional "[0 +-][num]" width formating field */ | |
| while (fmt[i] == '0' || fmt[i] == '+' || fmt[i] == '-' || | |
| fmt[i] == ' ') | |
| i++; | |
| if (fmt[i] >= '1' && fmt[i] <= '9') { | |
| i++; | |
| while (fmt[i] >= '0' && fmt[i] <= '9') | |
| i++; | |
| } | |
| if (fmt[i] == 's') { | |
| void *unsafe_ptr; | |
| /* try our best to copy */ | |
| if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) { | |
| err = -E2BIG; | |
| goto out; | |
| } | |
| unsafe_ptr = (void *)(long)args[fmt_cnt]; | |
| err = strncpy_from_kernel_nofault(bufs->buf[memcpy_cnt], | |
| unsafe_ptr, MAX_SEQ_PRINTF_STR_LEN); | |
| if (err < 0) | |
| bufs->buf[memcpy_cnt][0] = '\0'; | |
| params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt]; | |
| fmt_cnt++; | |
| memcpy_cnt++; | |
| continue; | |
| } | |
| if (fmt[i] == 'p') { | |
| if (fmt[i + 1] == 0 || | |
| fmt[i + 1] == 'K' || | |
| fmt[i + 1] == 'x' || | |
| fmt[i + 1] == 'B') { | |
| /* just kernel pointers */ | |
| params[fmt_cnt] = args[fmt_cnt]; | |
| fmt_cnt++; | |
| continue; | |
| } | |
| /* only support "%pI4", "%pi4", "%pI6" and "%pi6". */ | |
| if (fmt[i + 1] != 'i' && fmt[i + 1] != 'I') { | |
| err = -EINVAL; | |
| goto out; | |
| } | |
| if (fmt[i + 2] != '4' && fmt[i + 2] != '6') { | |
| err = -EINVAL; | |
| goto out; | |
| } | |
| if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) { | |
| err = -E2BIG; | |
| goto out; | |
| } | |
| copy_size = (fmt[i + 2] == '4') ? 4 : 16; | |
| err = copy_from_kernel_nofault(bufs->buf[memcpy_cnt], | |
| (void *) (long) args[fmt_cnt], | |
| copy_size); | |
| if (err < 0) | |
| memset(bufs->buf[memcpy_cnt], 0, copy_size); | |
| params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt]; | |
| i += 2; | |
| fmt_cnt++; | |
| memcpy_cnt++; | |
| continue; | |
| } | |
| if (fmt[i] == 'l') { | |
| i++; | |
| if (fmt[i] == 'l') | |
| i++; | |
| } | |
| if (fmt[i] != 'i' && fmt[i] != 'd' && | |
| fmt[i] != 'u' && fmt[i] != 'x' && | |
| fmt[i] != 'X') { | |
| err = -EINVAL; | |
| goto out; | |
| } | |
| params[fmt_cnt] = args[fmt_cnt]; | |
| fmt_cnt++; | |
| } | |
| /* Maximumly we can have MAX_SEQ_PRINTF_VARARGS parameter, just give | |
| * all of them to seq_printf(). | |
| */ | |
| seq_printf(m, fmt, params[0], params[1], params[2], params[3], | |
| params[4], params[5], params[6], params[7], params[8], | |
| params[9], params[10], params[11]); | |
| err = seq_has_overflowed(m) ? -EOVERFLOW : 0; | |
| out: | |
| this_cpu_dec(bpf_seq_printf_buf_used); | |
| return err; | |
| } | |
| BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) | |
| static const struct bpf_func_proto bpf_seq_printf_proto = { | |
| .func = bpf_seq_printf, | |
| .gpl_only = true, | |
| .ret_type = RET_INTEGER, | |
| .arg1_type = ARG_PTR_TO_BTF_ID, | |
| .arg1_btf_id = &btf_seq_file_ids[0], | |
| .arg2_type = ARG_PTR_TO_MEM, | |
| .arg3_type = ARG_CONST_SIZE, | |
| .arg4_type = ARG_PTR_TO_MEM_OR_NULL, | |
| .arg5_type = ARG_CONST_SIZE_OR_ZERO, | |
| }; | |
| BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) | |
| { | |
| return seq_write(m, data, len) ? -EOVERFLOW : 0; | |
| } | |
| static const struct bpf_func_proto bpf_seq_write_proto = { | |
| .func = bpf_seq_write, | |
| .gpl_only = true, | |
| .ret_type = RET_INTEGER, | |
| .arg1_type = ARG_PTR_TO_BTF_ID, | |
| .arg1_btf_id = &btf_seq_file_ids[0], | |
| .arg2_type = ARG_PTR_TO_MEM, | |
| .arg3_type = ARG_CONST_SIZE_OR_ZERO, | |
| }; | |
| BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, | |
| u32, btf_ptr_size, u64, flags) | |
| { | |
| const struct btf *btf; | |
| s32 btf_id; | |
| int ret; | |
| ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); | |
| if (ret) | |
| return ret; | |
| return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); | |
| } | |
| static const struct bpf_func_proto bpf_seq_printf_btf_proto = { | |
| .func = bpf_seq_printf_btf, | |
| .gpl_only = true, | |
| .ret_type = RET_INTEGER, | |
| .arg1_type = ARG_PTR_TO_BTF_ID, | |
| .arg1_btf_id = &btf_seq_file_ids[0], | |
| .arg2_type = ARG_PTR_TO_MEM, | |
| .arg3_type = ARG_CONST_SIZE_OR_ZERO, | |
| .arg4_type = ARG_ANYTHING, | |
| }; | |
| 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 __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); | |
| } | |
| /* | |
| * Support executing tracepoints in normal, irq, and nmi context that each call | |
| * bpf_perf_event_output | |
| */ | |
| struct bpf_trace_sample_data { | |
| struct perf_sample_data sds[3]; | |
| }; | |
| static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); | |
| static DEFINE_PER_CPU(int, bpf_trace_nest_level); | |
| BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, | |
| u64, flags, void *, data, u64, size) | |
| { | |
| struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds); | |
| int nest_level = this_cpu_inc_return(bpf_trace_nest_level); | |
| struct perf_raw_record raw = { | |
| .frag = { | |
| .size = size, | |
| .data = data, | |
| }, | |
| }; | |
| struct perf_sample_data *sd; | |
| int err; | |
| if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { | |
| err = -EBUSY; | |
| goto out; | |
| } | |
| sd = &sds->sds[nest_level - 1]; | |
| if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { | |
| err = -EINVAL; | |
| goto out; | |
| } | |
| perf_sample_data_init(sd, 0, 0); | |
| sd->raw = &raw; | |
| err = __bpf_perf_event_output(regs, map, flags, sd); | |
| out: | |
| this_cpu_dec(bpf_trace_nest_level); | |
| return err; | |
| } | |
| 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(int, bpf_event_output_nest_level); | |
| struct bpf_nested_pt_regs { | |
| struct pt_regs regs[3]; | |
| }; | |
| static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); | |
| static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); | |
| 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) | |
| { | |
| int nest_level = this_cpu_inc_return(bpf_event_output_nest_level); | |
| 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, | |
| }, | |
| }; | |
| struct perf_sample_data *sd; | |
| struct pt_regs *regs; | |
| u64 ret; | |
| if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { | |
| ret = -EBUSY; | |
| goto out; | |
| } | |
| sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); | |
| regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); | |
| perf_fetch_caller_regs(regs); | |
| perf_sample_data_init(sd, 0, 0); | |
| sd->raw = &raw; | |
| ret = __bpf_perf_event_output(regs, map, flags, sd); | |
| out: | |
| this_cpu_dec(bpf_event_output_nest_level); | |
| return ret; | |
| } | |
| BPF_CALL_0(bpf_get_current_task) | |
| { | |
| return (long) current; | |
| } | |
| 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, | |
| }; | |
| struct send_signal_irq_work { | |
| struct irq_work irq_work; | |
| struct task_struct *task; | |
| u32 sig; | |
| enum pid_type type; | |
| }; | |
| static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); | |
| static void do_bpf_send_signal(struct irq_work *entry) | |
| { | |
| struct send_signal_irq_work *work; | |
| work = container_of(entry, struct send_signal_irq_work, irq_work); | |
| group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); | |
| } | |
| static int bpf_send_signal_common(u32 sig, enum pid_type type) | |
| { | |
| struct send_signal_irq_work *work = NULL; | |
| /* Similar to bpf_probe_write_user, task needs to be | |
| * in a sound condition and kernel memory access be | |
| * permitted in order to send signal to the current | |
| * task. | |
| */ | |
| if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) | |
| return -EPERM; | |
| if (unlikely(uaccess_kernel())) | |
| return -EPERM; | |
| if (unlikely(!nmi_uaccess_okay())) | |
| return -EPERM; | |
| if (irqs_disabled()) { | |
| /* Do an early check on signal validity. Otherwise, | |
| * the error is lost in deferred irq_work. | |
| */ | |
| if (unlikely(!valid_signal(sig))) | |
| return -EINVAL; | |
| work = this_cpu_ptr(&send_signal_work); | |
| if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY) | |
| return -EBUSY; | |
| /* Add the current task, which is the target of sending signal, | |
| * to the irq_work. The current task may change when queued | |
| * irq works get executed. | |
| */ | |
| work->task = current; | |
| work->sig = sig; | |
| work->type = type; | |
| irq_work_queue(&work->irq_work); | |
| return 0; | |
| } | |
| return group_send_sig_info(sig, SEND_SIG_PRIV, current, type); | |
| } | |
| BPF_CALL_1(bpf_send_signal, u32, sig) | |
| { | |
| return bpf_send_signal_common(sig, PIDTYPE_TGID); | |
| } | |
| static const struct bpf_func_proto bpf_send_signal_proto = { | |
| .func = bpf_send_signal, | |
| .gpl_only = false, | |
| .ret_type = RET_INTEGER, | |
| .arg1_type = ARG_ANYTHING, | |
| }; | |
| BPF_CALL_1(bpf_send_signal_thread, u32, sig) | |
| { | |
| return bpf_send_signal_common(sig, PIDTYPE_PID); | |
| } | |
| static const struct bpf_func_proto bpf_send_signal_thread_proto = { | |
| .func = bpf_send_signal_thread, | |
| .gpl_only = false, | |
| .ret_type = RET_INTEGER, | |
| .arg1_type = ARG_ANYTHING, | |
| }; | |
| BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) | |
| { | |
| long len; | |
| char *p; | |
| if (!sz) | |
| return 0; | |
| p = d_path(path, buf, sz); | |
| if (IS_ERR(p)) { | |
| len = PTR_ERR(p); | |
| } else { | |
| len = buf + sz - p; | |
| memmove(buf, p, len); | |
| } | |
| return len; | |
| } | |
| BTF_SET_START(btf_allowlist_d_path) | |
| #ifdef CONFIG_SECURITY | |
| BTF_ID(func, security_file_permission) | |
| BTF_ID(func, security_inode_getattr) | |
| BTF_ID(func, security_file_open) | |
| #endif | |
| #ifdef CONFIG_SECURITY_PATH | |
| BTF_ID(func, security_path_truncate) | |
| #endif | |
| BTF_ID(func, vfs_truncate) | |
| BTF_ID(func, vfs_fallocate) | |
| BTF_ID(func, dentry_open) | |
| BTF_ID(func, vfs_getattr) | |
| BTF_ID(func, filp_close) | |
| BTF_SET_END(btf_allowlist_d_path) | |
| static bool bpf_d_path_allowed(const struct bpf_prog *prog) | |
| { | |
| return btf_id_set_contains(&btf_allowlist_d_path, prog->aux->attach_btf_id); | |
| } | |
| BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) | |
| static const struct bpf_func_proto bpf_d_path_proto = { | |
| .func = bpf_d_path, | |
| .gpl_only = false, | |
| .ret_type = RET_INTEGER, | |
| .arg1_type = ARG_PTR_TO_BTF_ID, | |
| .arg1_btf_id = &bpf_d_path_btf_ids[0], | |
| .arg2_type = ARG_PTR_TO_MEM, | |
| .arg3_type = ARG_CONST_SIZE_OR_ZERO, | |
| .allowed = bpf_d_path_allowed, | |
| }; | |
| #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ | |
| BTF_F_PTR_RAW | BTF_F_ZERO) | |
| static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, | |
| u64 flags, const struct btf **btf, | |
| s32 *btf_id) | |
| { | |
| const struct btf_type *t; | |
| if (unlikely(flags & ~(BTF_F_ALL))) | |
| return -EINVAL; | |
| if (btf_ptr_size != sizeof(struct btf_ptr)) | |
| return -EINVAL; | |
| *btf = bpf_get_btf_vmlinux(); | |
| if (IS_ERR_OR_NULL(*btf)) | |
| return PTR_ERR(*btf); | |
| if (ptr->type_id > 0) | |
| *btf_id = ptr->type_id; | |
| else | |
| return -EINVAL; | |
| if (*btf_id > 0) | |
| t = btf_type_by_id(*btf, *btf_id); | |
| if (*btf_id <= 0 || !t) | |
| return -ENOENT; | |
| return 0; | |
| } | |
| BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, | |
| u32, btf_ptr_size, u64, flags) | |
| { | |
| const struct btf *btf; | |
| s32 btf_id; | |
| int ret; | |
| ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); | |
| if (ret) | |
| return ret; | |
| return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, | |
| flags); | |
| } | |
| const struct bpf_func_proto bpf_snprintf_btf_proto = { | |
| .func = bpf_snprintf_btf, | |
| .gpl_only = false, | |
| .ret_type = RET_INTEGER, | |
| .arg1_type = ARG_PTR_TO_MEM, | |
| .arg2_type = ARG_CONST_SIZE, | |
| .arg3_type = ARG_PTR_TO_MEM, | |
| .arg4_type = ARG_CONST_SIZE, | |
| .arg5_type = ARG_ANYTHING, | |
| }; | |
| const struct bpf_func_proto * | |
| bpf_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_ktime_get_ns: | |
| return &bpf_ktime_get_ns_proto; | |
| case BPF_FUNC_ktime_get_boot_ns: | |
| return &bpf_ktime_get_boot_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_user: | |
| return &bpf_probe_read_user_proto; | |
| case BPF_FUNC_probe_read_kernel: | |
| return &bpf_probe_read_kernel_proto; | |
| case BPF_FUNC_probe_read_user_str: | |
| return &bpf_probe_read_user_str_proto; | |
| case BPF_FUNC_probe_read_kernel_str: | |
| return &bpf_probe_read_kernel_str_proto; | |
| #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE | |
| case BPF_FUNC_probe_read: | |
| return &bpf_probe_read_compat_proto; | |
| case BPF_FUNC_probe_read_str: | |
| return &bpf_probe_read_compat_str_proto; | |
| #endif | |
| #ifdef CONFIG_CGROUPS | |
| case BPF_FUNC_get_current_cgroup_id: | |
| return &bpf_get_current_cgroup_id_proto; | |
| #endif | |
| case BPF_FUNC_send_signal: | |
| return &bpf_send_signal_proto; | |
| case BPF_FUNC_send_signal_thread: | |
| return &bpf_send_signal_thread_proto; | |
| case BPF_FUNC_perf_event_read_value: | |
| return &bpf_perf_event_read_value_proto; | |
| case BPF_FUNC_get_ns_current_pid_tgid: | |
| return &bpf_get_ns_current_pid_tgid_proto; | |
| case BPF_FUNC_ringbuf_output: | |
| return &bpf_ringbuf_output_proto; | |
| case BPF_FUNC_ringbuf_reserve: | |
| return &bpf_ringbuf_reserve_proto; | |
| case BPF_FUNC_ringbuf_submit: | |
| return &bpf_ringbuf_submit_proto; | |
| case BPF_FUNC_ringbuf_discard: | |
| return &bpf_ringbuf_discard_proto; | |
| case BPF_FUNC_ringbuf_query: | |
| return &bpf_ringbuf_query_proto; | |
| case BPF_FUNC_jiffies64: | |
| return &bpf_jiffies64_proto; | |
| case BPF_FUNC_get_task_stack: | |
| return &bpf_get_task_stack_proto; | |
| case BPF_FUNC_copy_from_user: | |
| return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL; | |
| case BPF_FUNC_snprintf_btf: | |
| return &bpf_snprintf_btf_proto; | |
| case BPF_FUNC_bpf_per_cpu_ptr: | |
| return &bpf_per_cpu_ptr_proto; | |
| case BPF_FUNC_bpf_this_cpu_ptr: | |
| return &bpf_this_cpu_ptr_proto; | |
| 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; | |
| #ifdef CONFIG_BPF_KPROBE_OVERRIDE | |
| case BPF_FUNC_override_return: | |
| return &bpf_override_return_proto; | |
| #endif | |
| default: | |
| return bpf_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 bpf_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, | |
| }; | |
| BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, | |
| void *, buf, u32, size, u64, flags) | |
| { | |
| #ifndef CONFIG_X86 | |
| return -ENOENT; | |
| #else | |
| static const u32 br_entry_size = sizeof(struct perf_branch_entry); | |
| struct perf_branch_stack *br_stack = ctx->data->br_stack; | |
| u32 to_copy; | |
| if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) | |
| return -EINVAL; | |
| if (unlikely(!br_stack)) | |
| return -EINVAL; | |
| if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) | |
| return br_stack->nr * br_entry_size; | |
| if (!buf || (size % br_entry_size != 0)) | |
| return -EINVAL; | |
| to_copy = min_t(u32, br_stack->nr * br_entry_size, size); | |
| memcpy(buf, br_stack->entries, to_copy); | |
| return to_copy; | |
| #endif | |
| } | |
| static const struct bpf_func_proto bpf_read_branch_records_proto = { | |
| .func = bpf_read_branch_records, | |
| .gpl_only = true, | |
| .ret_type = RET_INTEGER, | |
| .arg1_type = ARG_PTR_TO_CTX, | |
| .arg2_type = ARG_PTR_TO_MEM_OR_NULL, | |
| .arg3_type = ARG_CONST_SIZE_OR_ZERO, | |
| .arg4_type = ARG_ANYTHING, | |
| }; | |
| 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_pe; | |
| case BPF_FUNC_get_stack: | |
| return &bpf_get_stack_proto_pe; | |
| case BPF_FUNC_perf_prog_read_value: | |
| return &bpf_perf_prog_read_value_proto; | |
| case BPF_FUNC_read_branch_records: | |
| return &bpf_read_branch_records_proto; | |
| default: | |
| return bpf_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. | |
| * | |
| * Since raw tracepoints run despite bpf_prog_active, support concurrent usage | |
| * in normal, irq, and nmi context. | |
| */ | |
| struct bpf_raw_tp_regs { | |
| struct pt_regs regs[3]; | |
| }; | |
| static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); | |
| static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); | |
| static struct pt_regs *get_bpf_raw_tp_regs(void) | |
| { | |
| struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); | |
| int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); | |
| if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { | |
| this_cpu_dec(bpf_raw_tp_nest_level); | |
| return ERR_PTR(-EBUSY); | |
| } | |
| return &tp_regs->regs[nest_level - 1]; | |
| } | |
| static void put_bpf_raw_tp_regs(void) | |
| { | |
| this_cpu_dec(bpf_raw_tp_nest_level); | |
| } | |
| 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 = get_bpf_raw_tp_regs(); | |
| int ret; | |
| if (IS_ERR(regs)) | |
| return PTR_ERR(regs); | |
| perf_fetch_caller_regs(regs); | |
| ret = ____bpf_perf_event_output(regs, map, flags, data, size); | |
| put_bpf_raw_tp_regs(); | |
| return ret; | |
| } | |
| 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, | |
| }; | |
| extern const struct bpf_func_proto bpf_skb_output_proto; | |
| extern const struct bpf_func_proto bpf_xdp_output_proto; | |
| BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, | |
| struct bpf_map *, map, u64, flags) | |
| { | |
| struct pt_regs *regs = get_bpf_raw_tp_regs(); | |
| int ret; | |
| if (IS_ERR(regs)) | |
| return PTR_ERR(regs); | |
| perf_fetch_caller_regs(regs); | |
| /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ | |
| ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, | |
| flags, 0, 0); | |
| put_bpf_raw_tp_regs(); | |
| return ret; | |
| } | |
| 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 = get_bpf_raw_tp_regs(); | |
| int ret; | |
| if (IS_ERR(regs)) | |
| return PTR_ERR(regs); | |
| perf_fetch_caller_regs(regs); | |
| ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, | |
| (unsigned long) size, flags, 0); | |
| put_bpf_raw_tp_regs(); | |
| return ret; | |
| } | |
| 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 bpf_tracing_func_proto(func_id, prog); | |
| } | |
| } | |
| const struct bpf_func_proto * | |
| tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
| { | |
| switch (func_id) { | |
| #ifdef CONFIG_NET | |
| case BPF_FUNC_skb_output: | |
| return &bpf_skb_output_proto; | |
| case BPF_FUNC_xdp_output: | |
| return &bpf_xdp_output_proto; | |
| case BPF_FUNC_skc_to_tcp6_sock: | |
| return &bpf_skc_to_tcp6_sock_proto; | |
| case BPF_FUNC_skc_to_tcp_sock: | |
| return &bpf_skc_to_tcp_sock_proto; | |
| case BPF_FUNC_skc_to_tcp_timewait_sock: | |
| return &bpf_skc_to_tcp_timewait_sock_proto; | |
| case BPF_FUNC_skc_to_tcp_request_sock: | |
| return &bpf_skc_to_tcp_request_sock_proto; | |
| case BPF_FUNC_skc_to_udp6_sock: | |
| return &bpf_skc_to_udp6_sock_proto; | |
| #endif | |
| case BPF_FUNC_seq_printf: | |
| return prog->expected_attach_type == BPF_TRACE_ITER ? | |
| &bpf_seq_printf_proto : | |
| NULL; | |
| case BPF_FUNC_seq_write: | |
| return prog->expected_attach_type == BPF_TRACE_ITER ? | |
| &bpf_seq_write_proto : | |
| NULL; | |
| case BPF_FUNC_seq_printf_btf: | |
| return prog->expected_attach_type == BPF_TRACE_ITER ? | |
| &bpf_seq_printf_btf_proto : | |
| NULL; | |
| case BPF_FUNC_d_path: | |
| return &bpf_d_path_proto; | |
| default: | |
| return raw_tp_prog_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) | |
| { | |
| if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS) | |
| return false; | |
| if (type != BPF_READ) | |
| return false; | |
| if (off % size != 0) | |
| return false; | |
| return true; | |
| } | |
| static bool tracing_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(__u64) * MAX_BPF_FUNC_ARGS) | |
| return false; | |
| if (type != BPF_READ) | |
| return false; | |
| if (off % size != 0) | |
| return false; | |
| return btf_ctx_access(off, size, type, prog, info); | |
| } | |
| int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, | |
| const union bpf_attr *kattr, | |
| union bpf_attr __user *uattr) | |
| { | |
| return -ENOTSUPP; | |
| } | |
| 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 = { | |
| #ifdef CONFIG_NET | |
| .test_run = bpf_prog_test_run_raw_tp, | |
| #endif | |
| }; | |
| const struct bpf_verifier_ops tracing_verifier_ops = { | |
| .get_func_proto = tracing_prog_func_proto, | |
| .is_valid_access = tracing_prog_is_valid_access, | |
| }; | |
| const struct bpf_prog_ops tracing_prog_ops = { | |
| .test_run = bpf_prog_test_run_tracing, | |
| }; | |
| 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 *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 = bpf_event_rcu_dereference(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 *old_array; | |
| struct bpf_prog_array *new_array; | |
| int ret; | |
| mutex_lock(&bpf_event_mutex); | |
| if (!event->prog) | |
| goto unlock; | |
| old_array = bpf_event_rcu_dereference(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 = {}; | |
| struct bpf_prog_array *progs; | |
| u32 *ids, prog_cnt, ids_len; | |
| int ret; | |
| if (!perfmon_capable()) | |
| 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); | |
| progs = bpf_event_rcu_dereference(event->tp_event->prog_array); | |
| ret = bpf_prog_array_copy_info(progs, 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) | |
| { | |
| cant_sleep(); | |
| rcu_read_lock(); | |
| (void) BPF_PROG_RUN(prog, args); | |
| 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; | |
| } | |
| static int __init send_signal_irq_work_init(void) | |
| { | |
| int cpu; | |
| struct send_signal_irq_work *work; | |
| for_each_possible_cpu(cpu) { | |
| work = per_cpu_ptr(&send_signal_work, cpu); | |
| init_irq_work(&work->irq_work, do_bpf_send_signal); | |
| } | |
| return 0; | |
| } | |
| subsys_initcall(send_signal_irq_work_init); | |
| #ifdef CONFIG_MODULES | |
| static int bpf_event_notify(struct notifier_block *nb, unsigned long op, | |
| void *module) | |
| { | |
| struct bpf_trace_module *btm, *tmp; | |
| struct module *mod = module; | |
| int ret = 0; | |
| if (mod->num_bpf_raw_events == 0 || | |
| (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) | |
| goto out; | |
| 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); | |
| } else { | |
| ret = -ENOMEM; | |
| } | |
| 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); | |
| out: | |
| return notifier_from_errno(ret); | |
| } | |
| static struct notifier_block bpf_module_nb = { | |
| .notifier_call = bpf_event_notify, | |
| }; | |
| static int __init bpf_event_init(void) | |
| { | |
| register_module_notifier(&bpf_module_nb); | |
| return 0; | |
| } | |
| fs_initcall(bpf_event_init); | |
| #endif /* CONFIG_MODULES */ |