From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx>
Use the stack of stack_trace_call() instead of check_stack() as
the test pointer for max stack size. It makes it a bit cleaner
and a little more accurate.
Adding stable, as a later fix depends on this patch.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_stack.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 42ca822..dc02e29 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -39,20 +39,21 @@ static DEFINE_MUTEX(stack_sysctl_mutex);
int stack_tracer_enabled;
static int last_stack_tracer_enabled;
-static inline void check_stack(void)
+static inline void
+check_stack(unsigned long *stack)
{
unsigned long this_size, flags;
unsigned long *p, *top, *start;
int i;
- this_size = ((unsigned long)&this_size) & (THREAD_SIZE-1);
+ this_size = ((unsigned long)stack) & (THREAD_SIZE-1);
this_size = THREAD_SIZE - this_size;
if (this_size <= max_stack_size)
return;
/* we do not handle interrupt stacks yet */
- if (!object_is_on_stack(&this_size))
+ if (!object_is_on_stack(stack))
return;
local_irq_save(flags);
@@ -73,7 +74,7 @@ static inline void check_stack(void)
* Now find where in the stack these are.
*/
i = 0;
- start = &this_size;
+ start = stack;
top = (unsigned long *)
(((unsigned long)start & ~(THREAD_SIZE-1)) + THREAD_SIZE);
@@ -113,6 +114,7 @@ static void
stack_trace_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *pt_regs)
{
+ unsigned long stack;
int cpu;
preempt_disable_notrace();
@@ -122,7 +124,7 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip,
if (per_cpu(trace_active, cpu)++ != 0)
goto out;
- check_stack();
+ check_stack(&stack);
out:
per_cpu(trace_active, cpu)--;
--
1.7.10.4
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