From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932773Ab3EFW5D (ORCPT ); Mon, 6 May 2013 18:57:03 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36107 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932739Ab3EFW5A (ORCPT ); Mon, 6 May 2013 18:57:00 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Steven Rostedt Subject: [ 20/63] tracing: Use stack of calling function for stack tracer Date: Mon, 6 May 2013 15:55:58 -0700 Message-Id: <20130506225319.936185611@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.rc0.20.gb99dd2e In-Reply-To: <20130506225314.802167948@linuxfoundation.org> References: <20130506225314.802167948@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Steven Rostedt (Red Hat)" commit 87889501d0adfae10e3b0f0e6f2d7536eed9ae84 upstream. 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. Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_stack.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -40,20 +40,21 @@ 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); @@ -74,7 +75,7 @@ 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 inline void check_stack(void) static void stack_trace_call(unsigned long ip, unsigned long parent_ip) { + unsigned long stack; int cpu; if (unlikely(!ftrace_enabled || stack_trace_disabled)) @@ -125,7 +127,7 @@ stack_trace_call(unsigned long ip, unsig if (per_cpu(trace_active, cpu)++ != 0) goto out; - check_stack(); + check_stack(&stack); out: per_cpu(trace_active, cpu)--;