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Diffstat (limited to 'arch/x86/kernel/nmi.c')
-rw-r--r--arch/x86/kernel/nmi.c37
1 files changed, 24 insertions, 13 deletions
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 6fcb49ce50a1..b4872b999a71 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -87,6 +87,7 @@ __setup("unknown_nmi_panic", setup_unknown_nmi_panic);
#define nmi_to_desc(type) (&nmi_desc[type])
static u64 nmi_longest_ns = 1 * NSEC_PER_MSEC;
+
static int __init nmi_warning_debugfs(void)
{
debugfs_create_u64("nmi_longest_ns", 0644,
@@ -95,6 +96,20 @@ static int __init nmi_warning_debugfs(void)
}
fs_initcall(nmi_warning_debugfs);
+static void nmi_max_handler(struct irq_work *w)
+{
+ struct nmiaction *a = container_of(w, struct nmiaction, irq_work);
+ int remainder_ns, decimal_msecs;
+ u64 whole_msecs = ACCESS_ONCE(a->max_duration);
+
+ remainder_ns = do_div(whole_msecs, (1000 * 1000));
+ decimal_msecs = remainder_ns / 1000;
+
+ printk_ratelimited(KERN_INFO
+ "INFO: NMI handler (%ps) took too long to run: %lld.%03d msecs\n",
+ a->handler, whole_msecs, decimal_msecs);
+}
+
static int __kprobes nmi_handle(unsigned int type, struct pt_regs *regs, bool b2b)
{
struct nmi_desc *desc = nmi_to_desc(type);
@@ -110,26 +125,20 @@ static int __kprobes nmi_handle(unsigned int type, struct pt_regs *regs, bool b2
* to handle those situations.
*/
list_for_each_entry_rcu(a, &desc->head, list) {
- u64 before, delta, whole_msecs;
- int remainder_ns, decimal_msecs, thishandled;
+ int thishandled;
+ u64 delta;
- before = sched_clock();
+ delta = sched_clock();
thishandled = a->handler(type, regs);
handled += thishandled;
- delta = sched_clock() - before;
+ delta = sched_clock() - delta;
trace_nmi_handler(a->handler, (int)delta, thishandled);
- if (delta < nmi_longest_ns)
+ if (delta < nmi_longest_ns || delta < a->max_duration)
continue;
- nmi_longest_ns = delta;
- whole_msecs = delta;
- remainder_ns = do_div(whole_msecs, (1000 * 1000));
- decimal_msecs = remainder_ns / 1000;
- printk_ratelimited(KERN_INFO
- "INFO: NMI handler (%ps) took too long to run: "
- "%lld.%03d msecs\n", a->handler, whole_msecs,
- decimal_msecs);
+ a->max_duration = delta;
+ irq_work_queue(&a->irq_work);
}
rcu_read_unlock();
@@ -146,6 +155,8 @@ int __register_nmi_handler(unsigned int type, struct nmiaction *action)
if (!action->handler)
return -EINVAL;
+ init_irq_work(&action->irq_work, nmi_max_handler);
+
spin_lock_irqsave(&desc->lock, flags);
/*