[PATCH][GIT PULL][v3.6] tracing/syscalls: Fix perf syscall tracingwhen syscall_nr == -1

[Steven Rostedt]

Ingo,

Please pull the latest tip/perf/urgent tree, which can be found at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
tip/perf/urgent

Head SHA1: 60916a9382e88fbf5e54fd36a3e658efd7ab7bed


Will Deacon (1):
      tracing/syscalls: Fix perf syscall tracing when syscall_nr == -1

----
 kernel/trace/trace_syscalls.c |    4 ++++
 1 file changed, 4 insertions(+)
---------------------------
commit 60916a9382e88fbf5e54fd36a3e658efd7ab7bed
Author: Will Deacon <will.deacon@xxxxxxx>
Date:   Thu Aug 16 18:14:14 2012 +0100

    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@xxxxxxx
    
    Cc: Jason Baron <jbaron@xxxxxxxxxx>
    Cc: Wade Farnsworth <wade_farnsworth@xxxxxxxxxx>
    Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
    Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
    Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 60e4d78..6b245f64 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;
 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/