From: tip-bot for Steven Rostedt <srostedt@redhat.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com,
rostedt@goodmis.org, srostedt@redhat.com, tglx@linutronix.de,
mingo@elte.hu
Subject: [tip:perf/core] tracing, x86/irq: Do not trace arch_local_{*,irq_*}() functions
Date: Thu, 7 Jul 2011 21:43:51 GMT [thread overview]
Message-ID: <tip-e08fbb78f03fe2c4f88824faf6f51ce6af185e11@git.kernel.org> (raw)
In-Reply-To: <20110702033852.733414762@goodmis.org>
Commit-ID: e08fbb78f03fe2c4f88824faf6f51ce6af185e11
Gitweb: http://git.kernel.org/tip/e08fbb78f03fe2c4f88824faf6f51ce6af185e11
Author: Steven Rostedt <srostedt@redhat.com>
AuthorDate: Fri, 1 Jul 2011 23:04:36 -0400
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 7 Jul 2011 19:22:32 +0200
tracing, x86/irq: Do not trace arch_local_{*,irq_*}() functions
I triggered a triple fault with gcc 4.5.1 because it did not
honor the inline annotation to arch_local_save_flags() function
and that function was added to the pool of functions traced by
the function tracer.
When preempt_schedule() called arch_local_save_flags() (called
by irqs_disabled()), it was traced, but the first thing the
function tracer does is disable preemption. When it enables
preemption, the NEED_RESCHED flag will not have been cleared and
the preemption check will trigger the call to preempt_schedule()
again.
Although the dynamic function tracer crashed immediately, the
static version of the function tracer (CONFIG_DYNAMIC_FTRACE is
not set) actually was able to show where the problem was.
swapper-1 3.N.. 103885us : arch_local_save_flags <-preempt_schedule
swapper-1 3.N.. 103886us : arch_local_save_flags <-preempt_schedule
swapper-1 3.N.. 103886us : arch_local_save_flags <-preempt_schedule
swapper-1 3.N.. 103887us : arch_local_save_flags <-preempt_schedule
swapper-1 3.N.. 103887us : arch_local_save_flags <-preempt_schedule
swapper-1 3.N.. 103888us : arch_local_save_flags <-preempt_schedule
swapper-1 3.N.. 103888us : arch_local_save_flags <-preempt_schedule
It went on for a while before it triple faulted with a corrupted
stack.
The arch_local_save_flags and arch_local_irq_* functions should
not be traced. Even though they are marked as inline, gcc may
still make them a function and enable tracing of them.
The simple solution is to just mark them as notrace. I had to
add the <linux/types.h> for this file to include the notrace
tag.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20110702033852.733414762@goodmis.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/include/asm/irqflags.h | 11 ++++++-----
1 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
index 5745ce8..bba3cf8 100644
--- a/arch/x86/include/asm/irqflags.h
+++ b/arch/x86/include/asm/irqflags.h
@@ -60,23 +60,24 @@ static inline void native_halt(void)
#include <asm/paravirt.h>
#else
#ifndef __ASSEMBLY__
+#include <linux/types.h>
-static inline unsigned long arch_local_save_flags(void)
+static inline notrace unsigned long arch_local_save_flags(void)
{
return native_save_fl();
}
-static inline void arch_local_irq_restore(unsigned long flags)
+static inline notrace void arch_local_irq_restore(unsigned long flags)
{
native_restore_fl(flags);
}
-static inline void arch_local_irq_disable(void)
+static inline notrace void arch_local_irq_disable(void)
{
native_irq_disable();
}
-static inline void arch_local_irq_enable(void)
+static inline notrace void arch_local_irq_enable(void)
{
native_irq_enable();
}
@@ -102,7 +103,7 @@ static inline void halt(void)
/*
* For spinlocks, etc:
*/
-static inline unsigned long arch_local_irq_save(void)
+static inline notrace unsigned long arch_local_irq_save(void)
{
unsigned long flags = arch_local_save_flags();
arch_local_irq_disable();
next prev parent reply other threads:[~2011-07-07 21:44 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20110702030435.308336775@goodmis.org>
2011-07-02 3:04 ` [patch 01/11] x86/irqs: Do not trace arch_local_{*,irq_*} functions Steven Rostedt
2011-07-07 0:51 ` Steven Rostedt
2011-07-07 21:43 ` tip-bot for Steven Rostedt [this message]
2011-07-02 3:04 ` [patch 02/11] arm/irqs: " Steven Rostedt
2011-07-02 3:04 ` [patch 03/11] blackfin/irqs: " Steven Rostedt
2011-07-02 6:50 ` Mike Frysinger
2011-07-02 16:11 ` Steven Rostedt
2011-07-02 16:39 ` Mike Frysinger
2011-07-02 16:40 ` Mike Frysinger
2011-07-05 12:51 ` Steven Rostedt
2011-07-05 16:20 ` Mike Frysinger
2011-07-05 19:07 ` Mike Frysinger
2011-07-05 19:13 ` Steven Rostedt
2011-07-05 19:25 ` Mike Frysinger
2011-07-02 3:04 ` [patch 04/11] ia64/irqs: " Steven Rostedt
2011-07-02 3:04 ` [patch 05/11] microblaze/irqs: " Steven Rostedt
2011-07-05 10:43 ` Michal Simek
2011-07-05 12:49 ` Steven Rostedt
2011-07-02 3:04 ` [patch 06/11] mips/irqs: " Steven Rostedt
2011-07-02 3:04 ` [patch 07/11] parisc/irqs: " Steven Rostedt
2011-07-02 3:04 ` [patch 08/11] powerpc/irqs: " Steven Rostedt
2011-07-02 3:04 ` [patch 09/11] s390/irqs: " Steven Rostedt
2011-07-04 8:10 ` Martin Schwidefsky
2011-07-05 12:49 ` Steven Rostedt
2011-07-02 3:04 ` [patch 10/11] sh/unicore32/irqs: " Steven Rostedt
2011-07-04 1:56 ` Guan Xuetao
2011-07-05 12:50 ` Steven Rostedt
2011-07-11 3:34 ` Paul Mundt
2011-07-13 1:36 ` Steven Rostedt
2011-07-02 3:04 ` [patch 11/11] sparc/irqs: " Steven Rostedt
2011-07-02 4:11 ` David Miller
2011-07-05 12:49 ` Steven Rostedt
2011-07-06 6:43 ` David Miller
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