From: Leo Yan <leo.yan@linaro.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
bpf@vger.kernel.org
Cc: Leo Yan <leo.yan@linaro.org>
Subject: [PATCH] perf trace: Fix segmentation fault when access syscall info
Date: Fri, 9 Aug 2019 18:47:52 +0800 [thread overview]
Message-ID: <20190809104752.27338-1-leo.yan@linaro.org> (raw)
'perf trace' reports the segmentation fault as below on Arm64:
# perf trace -e string -e augmented_raw_syscalls.c
LLVM: dumping tools/perf/examples/bpf/augmented_raw_syscalls.o
perf: Segmentation fault
Obtained 12 stack frames.
perf(sighandler_dump_stack+0x47) [0xaaaaac96ac87]
linux-vdso.so.1(+0x5b7) [0xffffadbeb5b7]
/lib/aarch64-linux-gnu/libc.so.6(strlen+0x10) [0xfffface7d5d0]
/lib/aarch64-linux-gnu/libc.so.6(_IO_vfprintf+0x1ac7) [0xfffface49f97]
/lib/aarch64-linux-gnu/libc.so.6(__vsnprintf_chk+0xc7) [0xffffacedfbe7]
perf(scnprintf+0x97) [0xaaaaac9ca3ff]
perf(+0x997bb) [0xaaaaac8e37bb]
perf(cmd_trace+0x28e7) [0xaaaaac8ec09f]
perf(+0xd4a13) [0xaaaaac91ea13]
perf(main+0x62f) [0xaaaaac8a147f]
/lib/aarch64-linux-gnu/libc.so.6(__libc_start_main+0xe3) [0xfffface22d23]
perf(+0x57723) [0xaaaaac8a1723]
Segmentation fault
This issue is introduced by commit 30a910d7d3e0 ("perf trace:
Preallocate the syscall table"), it allocates trace->syscalls.table[]
array and the element count is 'trace->sctbl->syscalls.nr_entries';
but on Arm64, the system call number is not continuously used; e.g. the
syscall maximum id is 436 but the real entries is only 281. So the
table is allocated with 'nr_entries' as the element count, but it
accesses the table with the syscall id, which might be out of the bound
of the array and cause the segmentation fault.
This patch allocates trace->syscalls.table[] with the element count is
'trace->sctbl->syscalls.max_id + 1', this allows any id to access the
table without out of the bound.
Fixes: 30a910d7d3e0 ("perf trace: Preallocate the syscall table")
Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
tools/perf/builtin-trace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 75eb3811e942..d553d06a9aeb 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1492,7 +1492,7 @@ static int trace__read_syscall_info(struct trace *trace, int id)
const char *name = syscalltbl__name(trace->sctbl, id);
if (trace->syscalls.table == NULL) {
- trace->syscalls.table = calloc(trace->sctbl->syscalls.nr_entries, sizeof(*sc));
+ trace->syscalls.table = calloc(trace->sctbl->syscalls.max_id + 1, sizeof(*sc));
if (trace->syscalls.table == NULL)
return -ENOMEM;
}
--
2.17.1
next reply other threads:[~2019-08-09 10:48 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-09 10:47 Leo Yan [this message]
2019-08-09 13:25 ` [PATCH] perf trace: Fix segmentation fault when access syscall info Arnaldo Carvalho de Melo
2019-08-09 13:44 ` Leo Yan
2019-08-09 16:03 ` Arnaldo Carvalho de Melo
2019-08-15 9:22 ` [tip:perf/core] perf trace: Fix segmentation fault when access syscall info on arm64 tip-bot for Leo Yan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190809104752.27338-1-leo.yan@linaro.org \
--to=leo.yan@linaro.org \
--cc=acme@kernel.org \
--cc=alexander.shishkin@linux.intel.com \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=jolsa@redhat.com \
--cc=kafai@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=namhyung@kernel.org \
--cc=netdev@vger.kernel.org \
--cc=songliubraving@fb.com \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).