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authorDaniel Mentz <danielmentz@google.com>2016-08-05 03:56:53 +0300
committerVineet Gupta <vgupta@synopsys.com>2016-08-10 20:14:07 +0300
commit18b43e89d295cc65151c505c643c98fb2c320e59 (patch)
tree6a4b3936ca2d3fbfdb577f6525d18b468f19879c /arch/arc
parent29b4817d4018df78086157ea3a55c1d9424a7cfc (diff)
downloadlinux-18b43e89d295cc65151c505c643c98fb2c320e59.tar.xz
ARC: Call trace_hardirqs_on() before enabling irqs
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>
Diffstat (limited to 'arch/arc')
-rw-r--r--arch/arc/include/asm/irqflags-compact.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arc/include/asm/irqflags-compact.h b/arch/arc/include/asm/irqflags-compact.h
index c1d36458bfb7..4c6eed80cd8b 100644
--- a/arch/arc/include/asm/irqflags-compact.h
+++ b/arch/arc/include/asm/irqflags-compact.h
@@ -188,10 +188,10 @@ 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__ */