diff options
| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2022-07-07 14:39:00 +0530 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-07-17 10:59:52 -0300 |
| commit | 4b335e1e0d6f8fa91dac615a44b123c9f26e93d3 (patch) | |
| tree | ddb4ad5771f63aff2dcc047af76bb49bda199594 | |
| parent | deb44a6249f696106645c63c0603eab08a6122af (diff) | |
perf trace: Fix SIGSEGV when processing syscall args
On powerpc, 'perf trace' is crashing with a SIGSEGV when trying to
process a perf.data file created with 'perf trace record -p':
#0 0x00000001225b8988 in syscall_arg__scnprintf_augmented_string <snip> at builtin-trace.c:1492
#1 syscall_arg__scnprintf_filename <snip> at builtin-trace.c:1492
#2 syscall_arg__scnprintf_filename <snip> at builtin-trace.c:1486
#3 0x00000001225bdd9c in syscall_arg_fmt__scnprintf_val <snip> at builtin-trace.c:1973
#4 syscall__scnprintf_args <snip> at builtin-trace.c:2041
#5 0x00000001225bff04 in trace__sys_enter <snip> at builtin-trace.c:2319
That points to the below code in tools/perf/builtin-trace.c:
/*
* If this is raw_syscalls.sys_enter, then it always comes with the 6 possible
* arguments, even if the syscall being handled, say "openat", uses only 4 arguments
* this breaks syscall__augmented_args() check for augmented args, as we calculate
* syscall->args_size using each syscalls:sys_enter_NAME tracefs format file,
* so when handling, say the openat syscall, we end up getting 6 args for the
* raw_syscalls:sys_enter event, when we expected just 4, we end up mistakenly
* thinking that the extra 2 u64 args are the augmented filename, so just check
* here and avoid using augmented syscalls when the evsel is the raw_syscalls one.
*/
if (evsel != trace->syscalls.events.sys_enter)
augmented_args = syscall__augmented_args(sc, sample, &augmented_args_size, trace->raw_augmented_syscalls_args_size);
As the comment points out, we should not be trying to augment the args
for raw_syscalls. However, when processing a perf.data file, we are not
initializing those properly. Fix the same.
Reported-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20220707090900.572584-1-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/builtin-trace.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 897fc504918b..f075cf37a65e 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -4280,6 +4280,7 @@ static int trace__replay(struct trace *trace) goto out; evsel = evlist__find_tracepoint_by_name(session->evlist, "raw_syscalls:sys_enter"); + trace->syscalls.events.sys_enter = evsel; /* older kernels have syscalls tp versus raw_syscalls */ if (evsel == NULL) evsel = evlist__find_tracepoint_by_name(session->evlist, "syscalls:sys_enter"); @@ -4292,6 +4293,7 @@ static int trace__replay(struct trace *trace) } evsel = evlist__find_tracepoint_by_name(session->evlist, "raw_syscalls:sys_exit"); + trace->syscalls.events.sys_exit = evsel; if (evsel == NULL) evsel = evlist__find_tracepoint_by_name(session->evlist, "syscalls:sys_exit"); if (evsel && |