linux-hardened/arch/x86/include/asm/irq.h
Michel Lespinasse b52e0a7c4e 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>
2013-06-20 14:00:21 +02:00

49 lines
1.1 KiB
C

#ifndef _ASM_X86_IRQ_H
#define _ASM_X86_IRQ_H
/*
* (C) 1992, 1993 Linus Torvalds, (C) 1997 Ingo Molnar
*
* IRQ/IPI changes taken from work by Thomas Radke
* <tomsoft@informatik.tu-chemnitz.de>
*/
#include <asm/apicdef.h>
#include <asm/irq_vectors.h>
static inline int irq_canonicalize(int irq)
{
return ((irq == 2) ? 9 : irq);
}
#ifdef CONFIG_X86_32
extern void irq_ctx_init(int cpu);
#else
# define irq_ctx_init(cpu) do { } while (0)
#endif
#define __ARCH_HAS_DO_SOFTIRQ
#ifdef CONFIG_HOTPLUG_CPU
#include <linux/cpumask.h>
extern void fixup_irqs(void);
extern void irq_force_complete_move(int);
#endif
extern void (*x86_platform_ipi_callback)(void);
extern void native_init_IRQ(void);
extern bool handle_irq(unsigned irq, struct pt_regs *regs);
extern unsigned int do_IRQ(struct pt_regs *regs);
/* Interrupt vector management */
extern DECLARE_BITMAP(used_vectors, NR_VECTORS);
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 */