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| author | Michel Lespinasse <walken@google.com> | 2013-06-06 04:41:15 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-06-20 14:00:21 +0200 |
| commit | b52e0a7c4e4100f8683af508664e60e1603070f9 (patch) | |
| tree | 1688d563baa6a011bb2945d79050ecb008da9821 | |
| parent | 949785996ec2250fa958fc3a924e5186e9a8fa2c (diff) | |
| download | linux-b52e0a7c4e4100f8683af508664e60e1603070f9.tar.bz2 | |
x86: Fix trigger_all_cpu_backtrace() implementation
The following change fixes the x86 implementation of
trigger_all_cpu_backtrace(), which was previously (accidentally,
as far as I can tell) disabled to always return false as on
architectures that do not implement this function.
trigger_all_cpu_backtrace(), as defined in include/linux/nmi.h,
should call arch_trigger_all_cpu_backtrace() if available, or
return false if the underlying arch doesn't implement this
function.
x86 did provide a suitable arch_trigger_all_cpu_backtrace()
implementation, but it wasn't actually being used because it was
declared in asm/nmi.h, which linux/nmi.h doesn't include. Also,
linux/nmi.h couldn't easily be fixed by including asm/nmi.h,
because that file is not available on all architectures.
I am proposing to fix this by moving the x86 definition of
arch_trigger_all_cpu_backtrace() to asm/irq.h.
Tested via: echo l > /proc/sysrq-trigger
Before the change, this uses a fallback implementation which
shows backtraces on active CPUs (using
smp_call_function_interrupt() )
After the change, this shows NMI backtraces on all CPUs
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1370518875-1346-1-git-send-email-walken@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/include/asm/irq.h | 5 | ||||
| -rw-r--r-- | arch/x86/include/asm/nmi.h | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/apic/hw_nmi.c | 1 |
3 files changed, 7 insertions, 3 deletions
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h index ba870bb6dd8e..57873beb3292 100644 --- a/arch/x86/include/asm/irq.h +++ b/arch/x86/include/asm/irq.h @@ -41,4 +41,9 @@ extern int vector_used_by_percpu_irq(unsigned int vector); extern void init_ISA_irqs(void); +#ifdef CONFIG_X86_LOCAL_APIC +void arch_trigger_all_cpu_backtrace(void); +#define arch_trigger_all_cpu_backtrace arch_trigger_all_cpu_backtrace +#endif + #endif /* _ASM_X86_IRQ_H */ diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h index c0fa356e90de..86f9301903c8 100644 --- a/arch/x86/include/asm/nmi.h +++ b/arch/x86/include/asm/nmi.h @@ -18,9 +18,7 @@ extern int proc_nmi_enabled(struct ctl_table *, int , void __user *, size_t *, loff_t *); extern int unknown_nmi_panic; -void arch_trigger_all_cpu_backtrace(void); -#define arch_trigger_all_cpu_backtrace arch_trigger_all_cpu_backtrace -#endif +#endif /* CONFIG_X86_LOCAL_APIC */ #define NMI_FLAG_FIRST 1 diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c index 31cb9ae992b7..a698d7165c96 100644 --- a/arch/x86/kernel/apic/hw_nmi.c +++ b/arch/x86/kernel/apic/hw_nmi.c @@ -9,6 +9,7 @@ * */ #include <asm/apic.h> +#include <asm/nmi.h> #include <linux/cpumask.h> #include <linux/kdebug.h> |