From: Michel Lespinasse Date: Wed, 19 Jun 2013 00:05:22 +0000 (+1000) Subject: x86: fix trigger_all_cpu_backtrace() implementation X-Git-Tag: next-20130619~2^2~652 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0fe24676c138578eccad83157988d26e9bdaafec;p=karo-tx-linux.git x86: fix trigger_all_cpu_backtrace() implementation Fix 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: 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 Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton --- 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 +#include #include #include