diff options
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/Makefile | 2 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 51 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.h | 34 |
3 files changed, 80 insertions, 7 deletions
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 6575bb0a0434..aeba5ee7325a 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -31,6 +31,8 @@ ifdef CONFIG_GCOV_PROFILE_FTRACE GCOV_PROFILE := y endif +CFLAGS_bpf_trace.o := -I$(src) + CFLAGS_trace_benchmark.o := -I$(src) CFLAGS_trace_events_filter.o := -I$(src) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index e0b7775039ab..3cc0dcb60ca2 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -11,14 +11,19 @@ #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 <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)) @@ -374,6 +379,30 @@ static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype, } } +static DEFINE_RAW_SPINLOCK(trace_printk_lock); + +#define BPF_TRACE_PRINTK_SIZE 1024 + +static inline __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 @@ -483,8 +512,7 @@ fmt_next: */ #define __BPF_TP_EMIT() __BPF_ARG3_TP() #define __BPF_TP(...) \ - __trace_printk(0 /* Fake ip */, \ - fmt, ##__VA_ARGS__) + bpf_do_trace_printk(fmt, ##__VA_ARGS__) #define __BPF_ARG1_TP(...) \ ((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64)) \ @@ -521,10 +549,15 @@ static const struct bpf_func_proto bpf_trace_printk_proto = { 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 + * 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. */ - trace_printk_init_buffers(); + 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; } @@ -710,7 +743,9 @@ out: return err; } -static int bpf_seq_printf_btf_ids[5]; +BTF_ID_LIST(bpf_seq_printf_btf_ids) +BTF_ID(struct, seq_file) + static const struct bpf_func_proto bpf_seq_printf_proto = { .func = bpf_seq_printf, .gpl_only = true, @@ -728,7 +763,9 @@ BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) return seq_write(m, data, len) ? -EOVERFLOW : 0; } -static int bpf_seq_write_btf_ids[5]; +BTF_ID_LIST(bpf_seq_write_btf_ids) +BTF_ID(struct, seq_file) + static const struct bpf_func_proto bpf_seq_write_proto = { .func = bpf_seq_write, .gpl_only = true, diff --git a/kernel/trace/bpf_trace.h b/kernel/trace/bpf_trace.h new file mode 100644 index 000000000000..9acbc11ac7bb --- /dev/null +++ b/kernel/trace/bpf_trace.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM bpf_trace + +#if !defined(_TRACE_BPF_TRACE_H) || defined(TRACE_HEADER_MULTI_READ) + +#define _TRACE_BPF_TRACE_H + +#include <linux/tracepoint.h> + +TRACE_EVENT(bpf_trace_printk, + + TP_PROTO(const char *bpf_string), + + TP_ARGS(bpf_string), + + TP_STRUCT__entry( + __string(bpf_string, bpf_string) + ), + + TP_fast_assign( + __assign_str(bpf_string, bpf_string); + ), + + TP_printk("%s", __get_str(bpf_string)) +); + +#endif /* _TRACE_BPF_TRACE_H */ + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . +#define TRACE_INCLUDE_FILE bpf_trace + +#include <trace/define_trace.h> |