diff options
Diffstat (limited to 'arch/x86/kernel/traps.c')
| -rw-r--r-- | arch/x86/kernel/traps.c | 102 |
1 files changed, 51 insertions, 51 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index c76aaca5694d..b9b67166f9de 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -84,6 +84,11 @@ EXPORT_SYMBOL_GPL(used_vectors); static int ignore_nmis; int unknown_nmi_panic; +/* + * Prevent NMI reason port (0x61) being accessed simultaneously, can + * only be used in NMI handler. + */ +static DEFINE_RAW_SPINLOCK(nmi_reason_lock); static inline void conditional_sti(struct pt_regs *regs) { @@ -310,15 +315,15 @@ static int __init setup_unknown_nmi_panic(char *str) __setup("unknown_nmi_panic", setup_unknown_nmi_panic); static notrace __kprobes void -mem_parity_error(unsigned char reason, struct pt_regs *regs) +pci_serr_error(unsigned char reason, struct pt_regs *regs) { - printk(KERN_EMERG - "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", - reason, smp_processor_id()); - - printk(KERN_EMERG - "You have some hardware problem, likely on the PCI bus.\n"); + pr_emerg("NMI: PCI system error (SERR) for reason %02x on CPU %d.\n", + reason, smp_processor_id()); + /* + * On some machines, PCI SERR line is used to report memory + * errors. EDAC makes use of it. + */ #if defined(CONFIG_EDAC) if (edac_handler_set()) { edac_atomic_assert_error(); @@ -329,11 +334,11 @@ mem_parity_error(unsigned char reason, struct pt_regs *regs) if (panic_on_unrecovered_nmi) panic("NMI: Not continuing"); - printk(KERN_EMERG "Dazed and confused, but trying to continue\n"); + pr_emerg("Dazed and confused, but trying to continue\n"); - /* Clear and disable the memory parity error line. */ - reason = (reason & 0xf) | 4; - outb(reason, 0x61); + /* Clear and disable the PCI SERR error line. */ + reason = (reason & NMI_REASON_CLEAR_MASK) | NMI_REASON_CLEAR_SERR; + outb(reason, NMI_REASON_PORT); } static notrace __kprobes void @@ -341,15 +346,17 @@ io_check_error(unsigned char reason, struct pt_regs *regs) { unsigned long i; - printk(KERN_EMERG "NMI: IOCK error (debug interrupt?)\n"); + pr_emerg( + "NMI: IOCK error (debug interrupt?) for reason %02x on CPU %d.\n", + reason, smp_processor_id()); show_registers(regs); if (panic_on_io_nmi) panic("NMI IOCK error: Not continuing"); /* Re-enable the IOCK line, wait for a few seconds */ - reason = (reason & 0xf) | 8; - outb(reason, 0x61); + reason = (reason & NMI_REASON_CLEAR_MASK) | NMI_REASON_CLEAR_IOCHK; + outb(reason, NMI_REASON_PORT); i = 20000; while (--i) { @@ -357,8 +364,8 @@ io_check_error(unsigned char reason, struct pt_regs *regs) udelay(100); } - reason &= ~8; - outb(reason, 0x61); + reason &= ~NMI_REASON_CLEAR_IOCHK; + outb(reason, NMI_REASON_PORT); } static notrace __kprobes void @@ -377,57 +384,50 @@ unknown_nmi_error(unsigned char reason, struct pt_regs *regs) return; } #endif - printk(KERN_EMERG - "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", - reason, smp_processor_id()); + pr_emerg("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", + reason, smp_processor_id()); - printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n"); + pr_emerg("Do you have a strange power saving mode enabled?\n"); if (unknown_nmi_panic || panic_on_unrecovered_nmi) panic("NMI: Not continuing"); - printk(KERN_EMERG "Dazed and confused, but trying to continue\n"); + pr_emerg("Dazed and confused, but trying to continue\n"); } static notrace __kprobes void default_do_nmi(struct pt_regs *regs) { unsigned char reason = 0; - int cpu; - cpu = smp_processor_id(); - - /* Only the BSP gets external NMIs from the system. */ - if (!cpu) - reason = get_nmi_reason(); + /* + * CPU-specific NMI must be processed before non-CPU-specific + * NMI, otherwise we may lose it, because the CPU-specific + * NMI can not be detected/processed on other CPUs. + */ + if (notify_die(DIE_NMI, "nmi", regs, 0, 2, SIGINT) == NOTIFY_STOP) + return; - if (!(reason & 0xc0)) { - if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT) - == NOTIFY_STOP) - return; + /* Non-CPU-specific NMI: NMI sources can be processed on any CPU */ + raw_spin_lock(&nmi_reason_lock); + reason = get_nmi_reason(); -#ifdef CONFIG_X86_LOCAL_APIC - if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) - == NOTIFY_STOP) - return; + if (reason & NMI_REASON_MASK) { + if (reason & NMI_REASON_SERR) + pci_serr_error(reason, regs); + else if (reason & NMI_REASON_IOCHK) + io_check_error(reason, regs); +#ifdef CONFIG_X86_32 + /* + * Reassert NMI in case it became active + * meanwhile as it's edge-triggered: + */ + reassert_nmi(); #endif - unknown_nmi_error(reason, regs); - + raw_spin_unlock(&nmi_reason_lock); return; } - if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP) - return; + raw_spin_unlock(&nmi_reason_lock); - /* AK: following checks seem to be broken on modern chipsets. FIXME */ - if (reason & 0x80) - mem_parity_error(reason, regs); - if (reason & 0x40) - io_check_error(reason, regs); -#ifdef CONFIG_X86_32 - /* - * Reassert NMI in case it became active meanwhile - * as it's edge-triggered: - */ - reassert_nmi(); -#endif + unknown_nmi_error(reason, regs); } dotraplinkage notrace __kprobes void |