diff options
| author | Song Liu <songliubraving@fb.com> | 2020-06-29 23:28:45 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-07-01 08:23:59 -0700 |
| commit | 2df6bb5493f83c7e818f66c384ea337c1b3da228 (patch) | |
| tree | 75e7a55fc744fe604e282de3be9e7be74468a5e5 /kernel | |
| parent | fa28dcb82a38f8e3993b0fae9106b1a80b59e4f0 (diff) | |
| download | linux-2df6bb5493f83c7e818f66c384ea337c1b3da228.tar.bz2 | |
bpf: Allow %pB in bpf_seq_printf() and bpf_trace_printk()
This makes it easy to dump stack trace in text.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200630062846.664389-4-songliubraving@fb.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 977ba3b6f6c6..1d874d8e4384 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -376,7 +376,7 @@ static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype, /* * Only limited trace_printk() conversion specifiers allowed: - * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pks %pus %s + * %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) @@ -420,6 +420,11 @@ BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 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]) && @@ -636,7 +641,8 @@ BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, if (fmt[i] == 'p') { if (fmt[i + 1] == 0 || fmt[i + 1] == 'K' || - fmt[i + 1] == 'x') { + fmt[i + 1] == 'x' || + fmt[i + 1] == 'B') { /* just kernel pointers */ params[fmt_cnt] = args[fmt_cnt]; fmt_cnt++; |