lkml.org 
[lkml]   [2010]   [May]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5/9] x86: Move trigger_all_cpu_backtrace to its own die_notifier
    Date
    From: Don Zickus <dzickus@redhat.com>

    As part of the transition of the nmi watchdog to something more
    generic, the trigger_all_cpu_backtrace code is getting left behind.
    Put it in its own die_notifier so it can still be used.

    V2:
    - use arch_spin_locks

    Signed-off-by: Don Zickus <dzickus@redhat.com>
    Cc: Ingo Molnar <mingo@elte.hu>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Cyrill Gorcunov <gorcunov@gmail.com>
    Cc: Eric Paris <eparis@redhat.com>
    Cc: Randy Dunlap <randy.dunlap@oracle.com>
    LKML-Reference: <1273266711-18706-6-git-send-email-dzickus@redhat.com>
    Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
    ---
    arch/x86/kernel/apic/hw_nmi.c | 65 ++++++++++++++++++++++++++++++++---------
    1 files changed, 51 insertions(+), 14 deletions(-)

    diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
    index 79425f9..8c3edfb 100644
    --- a/arch/x86/kernel/apic/hw_nmi.c
    +++ b/arch/x86/kernel/apic/hw_nmi.c
    @@ -17,6 +17,10 @@
    #include <linux/cpumask.h>
    #include <linux/kernel_stat.h>
    #include <asm/mce.h>
    +#include <linux/kdebug.h>
    +#include <linux/notifier.h>
    +#include <linux/kprobes.h>
    +

    #include <linux/nmi.h>
    #include <linux/module.h>
    @@ -54,20 +58,6 @@ int hw_nmi_is_cpu_stuck(struct pt_regs *regs)
    unsigned int sum;
    int cpu = smp_processor_id();

    - /* FIXME: cheap hack for this check, probably should get its own
    - * die_notifier handler
    - */
    - if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
    - static DEFINE_SPINLOCK(lock); /* Serialise the printks */
    -
    - spin_lock(&lock);
    - printk(KERN_WARNING "NMI backtrace for cpu %d\n", cpu);
    - show_regs(regs);
    - dump_stack();
    - spin_unlock(&lock);
    - cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
    - }
    -
    /* if we are doing an mce, just assume the cpu is not stuck */
    /* Could check oops_in_progress here too, but it's safer not to */
    if (mce_in_progress())
    @@ -109,6 +99,53 @@ void arch_trigger_all_cpu_backtrace(void)
    mdelay(1);
    }
    }
    +
    +static int __kprobes
    +arch_trigger_all_cpu_backtrace_handler(struct notifier_block *self,
    + unsigned long cmd, void *__args)
    +{
    + struct die_args *args = __args;
    + struct pt_regs *regs;
    + int cpu = smp_processor_id();
    +
    + switch (cmd) {
    + case DIE_NMI:
    + case DIE_NMI_IPI:
    + break;
    +
    + default:
    + return NOTIFY_DONE;
    + }
    +
    + regs = args->regs;
    +
    + if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
    + static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED;
    +
    + arch_spin_lock(&lock);
    + printk(KERN_WARNING "NMI backtrace for cpu %d\n", cpu);
    + show_regs(regs);
    + dump_stack();
    + arch_spin_unlock(&lock);
    + cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
    + return NOTIFY_STOP;
    + }
    +
    + return NOTIFY_DONE;
    +}
    +
    +static __read_mostly struct notifier_block backtrace_notifier = {
    + .notifier_call = arch_trigger_all_cpu_backtrace_handler,
    + .next = NULL,
    + .priority = 1
    +};
    +
    +static int __init register_trigger_all_cpu_backtrace(void)
    +{
    + register_die_notifier(&backtrace_notifier);
    + return 0;
    +}
    +early_initcall(register_trigger_all_cpu_backtrace);
    #endif

    /* STUB calls to mimic old nmi_watchdog behaviour */
    --
    1.6.2.3


    \
     
     \ /
      Last update: 2010-05-13 03:27    [W:0.035 / U:9.588 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site