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authorIngo Molnar <mingo@elte.hu>2008-05-12 19:20:48 (GMT)
committerThomas Gleixner <tglx@linutronix.de>2008-05-23 21:40:13 (GMT)
commit9f6b4e3f4a24f2590f1c96f117fc45fbea9b0fa4 (patch)
tree88ff9c7f68116addae7bf3f3b7c59e204be7d06e /kernel/trace/trace_sysprof.c
parentef4ab15ff34fd9c65e92bee70f58e7179da881c5 (diff)
ftrace: sysprof fix
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/trace/trace_sysprof.c')
-rw-r--r--kernel/trace/trace_sysprof.c28
1 files changed, 19 insertions, 9 deletions
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index 7f6fccc..f9a09fe 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -37,21 +37,26 @@ struct stack_frame {
static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
{
+ int ret;
+
if (!access_ok(VERIFY_READ, fp, sizeof(*frame)))
return 0;
- if (__copy_from_user_inatomic(frame, frame_pointer, sizeof(*frame)))
- return 0;
+ ret = 1;
+ pagefault_disable();
+ if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
+ ret = 0;
+ pagefault_enable();
- return 1;
+ return ret;
}
static void timer_notify(struct pt_regs *regs, int cpu)
{
- const void __user *frame_pointer;
struct trace_array_cpu *data;
struct stack_frame frame;
struct trace_array *tr;
+ const void __user *fp;
int is_user;
int i;
@@ -77,21 +82,26 @@ static void timer_notify(struct pt_regs *regs, int cpu)
trace_special(tr, data, 0, current->pid, regs->ip);
- frame_pointer = (void __user *)regs->bp;
+ fp = (void __user *)regs->bp;
for (i = 0; i < sample_max_depth; i++) {
- if (!copy_stack_frame(frame_pointer, &frame))
+ frame.next_fp = 0;
+ frame.return_address = 0;
+ if (!copy_stack_frame(fp, &frame))
break;
- if ((unsigned long)frame_pointer < regs->sp)
+ if ((unsigned long)fp < regs->sp)
break;
trace_special(tr, data, 1, frame.return_address,
- (unsigned long)frame_pointer);
- frame_pointer = frame.next_fp;
+ (unsigned long)fp);
+ fp = frame.next_fp;
}
trace_special(tr, data, 2, current->pid, i);
+ /*
+ * Special trace entry if we overflow the max depth:
+ */
if (i == sample_max_depth)
trace_special(tr, data, -1, -1, -1);
}

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