From: Song Liu <songliubraving@fb.com>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Cc: <peterz@infradead.org>, <ast@kernel.org>, <daniel@iogearbox.net>,
<kernel-team@fb.com>, <john.fastabend@gmail.com>,
<kpsingh@chromium.org>, Song Liu <songliubraving@fb.com>
Subject: [PATCH v2 bpf-next 3/4] bpf: allow %pB in bpf_seq_printf() and bpf_trace_printk()
Date: Thu, 25 Jun 2020 17:13:31 -0700 [thread overview]
Message-ID: <20200626001332.1554603-4-songliubraving@fb.com> (raw)
In-Reply-To: <20200626001332.1554603-1-songliubraving@fb.com>
This makes it easy to dump stack trace in text.
Signed-off-by: Song Liu <songliubraving@fb.com>
---
kernel/trace/bpf_trace.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 65fa62723e2f8..1cb90b0868817 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]) &&
@@ -479,7 +484,7 @@ BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
#define __BPF_TP_EMIT() __BPF_ARG3_TP()
#define __BPF_TP(...) \
__trace_printk(0 /* Fake ip */, \
- fmt, ##__VA_ARGS__)
+ fmt, ##__VA_ARGS__)\
#define __BPF_ARG1_TP(...) \
((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64)) \
@@ -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++;
--
2.24.1
next prev parent reply other threads:[~2020-06-26 0:14 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-26 0:13 [PATCH v2 bpf-next 0/4] bpf: introduce bpf_get_task_stack() Song Liu
2020-06-26 0:13 ` [PATCH v2 bpf-next 1/4] perf: export get/put_chain_entry() Song Liu
2020-06-26 11:00 ` Peter Zijlstra
2020-06-26 20:06 ` Andrii Nakryiko
2020-06-26 21:38 ` Song Liu
2020-06-26 21:29 ` Song Liu
2020-06-26 0:13 ` [PATCH v2 bpf-next 2/4] bpf: introduce helper bpf_get_task_stak() Song Liu
2020-06-26 15:40 ` Yonghong Song
2020-06-26 22:37 ` Song Liu
2020-06-26 20:17 ` Andrii Nakryiko
2020-06-26 20:22 ` Andrii Nakryiko
2020-06-26 22:45 ` Song Liu
2020-06-26 22:51 ` Andrii Nakryiko
2020-06-26 23:47 ` Song Liu
2020-06-27 0:06 ` Andrii Nakryiko
2020-06-26 0:13 ` Song Liu [this message]
2020-06-26 15:44 ` [Potential Spoof] [PATCH v2 bpf-next 3/4] bpf: allow %pB in bpf_seq_printf() and bpf_trace_printk() Yonghong Song
2020-06-26 0:13 ` [PATCH v2 bpf-next 4/4] selftests/bpf: add bpf_iter test with bpf_get_task_stack() Song Liu
2020-06-26 15:52 ` Yonghong Song
2020-06-26 20:21 ` Andrii Nakryiko
2020-06-26 23:05 ` Song Liu
2020-06-26 23:11 ` Andrii Nakryiko
2020-06-26 23:40 ` Song Liu
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