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Commit 87889501 authored by Steven Rostedt (Red Hat)'s avatar Steven Rostedt (Red Hat) Committed by Steven Rostedt
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tracing: Use stack of calling function for stack tracer 



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@vger.kernel.org
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent dd42cd3e

kernel/trace/trace_stack.c

+7 −5
Original line number Diff line number Diff line
@@ -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)--;