tracing/syscalls: Fix perf syscall tracing when syscall_nr == -1

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.

Link: http://lkml.kernel.org/r/1345137254-7377-1-git-send-email-will.deacon@arm.com

Cc: Jason Baron <jbaron@redhat.com>
Cc: Wade Farnsworth <wade_farnsworth@mentor.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Will Deacon 2012-08-16 18:14:14 +01:00 committed by Steven Rostedt
parent 26a4f3c08d
commit 60916a9382

View File

@ -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;