2012-10-24 06:03:09

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: [tip:perf/urgent] perf trace: Validate syscall id before growing syscall table

Commit-ID: 3a531260a14631ae8d231279b8738884bf808e7b
Gitweb: http://git.kernel.org/tip/3a531260a14631ae8d231279b8738884bf808e7b
Author: Arnaldo Carvalho de Melo <[email protected]>
AuthorDate: Sat, 20 Oct 2012 12:39:03 -0300
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Sun, 21 Oct 2012 23:07:36 -0200

perf trace: Validate syscall id before growing syscall table

In some cases the ID for a syscall read thru the raw_syscalls tracepoint
is bogus, still needs to be investigated why, but to make the tool more
robust first try to resolve the ID to a name via libaudit and if it
fails, don't grow the table.

Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/builtin-trace.c | 11 ++++++-----
1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index dec8ced..83c6515 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -56,6 +56,10 @@ static int trace__read_syscall_info(struct trace *trace, int id)
{
char tp_name[128];
struct syscall *sc;
+ const char *name = audit_syscall_to_name(id, trace->audit_machine);
+
+ if (name == NULL)
+ return -1;

if (id > trace->syscalls.max) {
struct syscall *nsyscalls = realloc(trace->syscalls.table, (id + 1) * sizeof(*sc));
@@ -75,11 +79,8 @@ static int trace__read_syscall_info(struct trace *trace, int id)
}

sc = trace->syscalls.table + id;
- sc->name = audit_syscall_to_name(id, trace->audit_machine);
- if (sc->name == NULL)
- return -1;
-
- sc->fmt = syscall_fmt__find(sc->name);
+ sc->name = name;
+ sc->fmt = syscall_fmt__find(sc->name);

snprintf(tp_name, sizeof(tp_name), "sys_enter_%s", sc->name);
sc->tp_format = event_format__new("syscalls", tp_name);