diff options
| author | Sasha Levin <alexander.levin@verizon.com> | 2016-08-30 21:59:56 -0400 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2016-08-31 19:21:09 -0400 |
| commit | 0e16c544ede2bc7954de7583cb2ff1594fb5db97 (patch) | |
| tree | 336f925f8fe3b316c561ff2641455beecb82e959 | |
| parent | e1052fbcb3d341d8088b8ffec73f3e5dbb37fe6d (diff) | |
ARC: Call trace_hardirqs_on() before enabling irqs
[ Upstream commit 18b43e89d295cc65151c505c643c98fb2c320e59 ]
trace_hardirqs_on_caller() in lockdep.c expects to be called before, not
after interrupts are actually enabled.
The following comment in kernel/locking/lockdep.c substantiates this
claim:
"
/*
* We're enabling irqs and according to our state above irqs weren't
* already enabled, yet we find the hardware thinks they are in fact
* enabled.. someone messed up their IRQ state tracing.
*/
"
An example can be found in include/linux/irqflags.h:
do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0)
Without this change, we hit the following DEBUG_LOCKS_WARN_ON.
[ 7.760000] ------------[ cut here ]------------
[ 7.760000] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:2711 resume_user_mode_begin+0x48/0xf0
[ 7.770000] DEBUG_LOCKS_WARN_ON(!irqs_disabled())
[ 7.780000] Modules linked in:
[ 7.780000] CPU: 0 PID: 1 Comm: init Not tainted 4.7.0-00003-gc668bb9-dirty #366
[ 7.790000]
[ 7.790000] Stack Trace:
[ 7.790000] arc_unwind_core.constprop.1+0xa4/0x118
[ 7.800000] warn_slowpath_fmt+0x72/0x158
[ 7.800000] resume_user_mode_begin+0x48/0xf0
[ 7.810000] ---[ end trace 6f6a7a8fae20d2f0 ]---
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
| -rw-r--r-- | arch/arc/include/asm/irqflags.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arc/include/asm/irqflags.h b/arch/arc/include/asm/irqflags.h index 27ecc6975a58..853a80ee7aaa 100644 --- a/arch/arc/include/asm/irqflags.h +++ b/arch/arc/include/asm/irqflags.h @@ -168,10 +168,10 @@ static inline int arch_irqs_disabled(void) .endm .macro IRQ_ENABLE scratch + TRACE_ASM_IRQ_ENABLE lr \scratch, [status32] or \scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK) flag \scratch - TRACE_ASM_IRQ_ENABLE .endm #endif /* __ASSEMBLY__ */ |