diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/nmi.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/nmi.c | 37 |
2 files changed, 27 insertions, 13 deletions
diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h index 86f9301903c8..5f2fc4441b11 100644 --- a/arch/x86/include/asm/nmi.h +++ b/arch/x86/include/asm/nmi.h @@ -1,6 +1,7 @@ #ifndef _ASM_X86_NMI_H #define _ASM_X86_NMI_H +#include <linux/irq_work.h> #include <linux/pm.h> #include <asm/irq.h> #include <asm/io.h> @@ -38,6 +39,8 @@ typedef int (*nmi_handler_t)(unsigned int, struct pt_regs *); struct nmiaction { struct list_head list; nmi_handler_t handler; + u64 max_duration; + struct irq_work irq_work; unsigned long flags; const char *name; }; 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); /* |