Commit-ID: b52e0a7c4e4100f8683af508664e60e1603070f9 Gitweb: http://git.kernel.org/tip/b52e0a7c4e4100f8683af508664e60e1603070f9 Author: Michel Lespinasse <wal...@google.com> AuthorDate: Thu, 6 Jun 2013 04:41:15 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 20 Jun 2013 14:00:21 +0200
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 <wal...@google.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Link: http://lkml.kernel.org/r/1370518875-1346-1-git-send-email-wal...@google.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/include/asm/irq.h | 5 +++++ arch/x86/include/asm/nmi.h | 4 +--- 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 ba870bb..57873be 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 c0fa356..86f9301 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 31cb9ae..a698d71 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> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
