lkml.org 
[lkml]   [2012]   [Aug]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] tracing/syscalls: fix perf syscall tracing when syscall_nr == -1
Date
syscall_get_nr can return -1 in the case that the task is not executing
a system call.

This patch fixes perf_syscall_{enter,exit} to check that the syscall
number is valid before using it as an index into a bitmap.

Cc: Jason Baron <jbaron@redhat.com>
Cc: Wade Farnsworth <wade_farnsworth@mentor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
kernel/trace/trace_syscalls.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 96fc733..4bc7d92 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -506,6 +506,8 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
int size;

syscall_nr = syscall_get_nr(current, regs);
+ if (syscall_nr < 0)
+ return;
if (!test_bit(syscall_nr, enabled_perf_enter_syscalls))
return;

@@ -580,6 +582,8 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
int size;

syscall_nr = syscall_get_nr(current, regs);
+ if (syscall_nr < 0)
+ return;
if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
return;

--
1.7.4.1


\
 
 \ /
  Last update: 2012-08-16 20:01    [W:0.257 / U:0.400 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site