diff options
Diffstat (limited to 'arch/x86/kernel/traps.c')
| -rw-r--r-- | arch/x86/kernel/traps.c | 131 |
1 files changed, 64 insertions, 67 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index cb838ca..b9b6716 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -83,6 +83,13 @@ 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) { if (regs->flags & X86_EFLAGS_IF) @@ -300,16 +307,23 @@ gp_in_kernel: die("general protection fault", regs, error_code); } -static notrace __kprobes void -mem_parity_error(unsigned char reason, struct pt_regs *regs) +static int __init setup_unknown_nmi_panic(char *str) { - printk(KERN_EMERG - "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", - reason, smp_processor_id()); + unknown_nmi_panic = 1; + return 1; +} +__setup("unknown_nmi_panic", setup_unknown_nmi_panic); - printk(KERN_EMERG - "You have some hardware problem, likely on the PCI bus.\n"); +static notrace __kprobes void +pci_serr_error(unsigned char reason, struct pt_regs *regs) +{ + 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(); @@ -320,11 +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 @@ -332,22 +346,26 @@ 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 = 2000; - while (--i) - udelay(1000); + i = 20000; + while (--i) { + touch_nmi_watchdog(); + udelay(100); + } - reason &= ~8; - outb(reason, 0x61); + reason &= ~NMI_REASON_CLEAR_IOCHK; + outb(reason, NMI_REASON_PORT); } static notrace __kprobes void @@ -366,69 +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"); - if (panic_on_unrecovered_nmi) + 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(); - - if (!(reason & 0xc0)) { - if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT) - == NOTIFY_STOP) - return; + /* + * 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; -#ifdef CONFIG_X86_LOCAL_APIC - if (notify_die(DIE_NMI, "nmi", 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(); -#ifndef CONFIG_LOCKUP_DETECTOR + 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 /* - * Ok, so this is none of the documented NMI sources, - * so it must be the NMI watchdog. + * Reassert NMI in case it became active + * meanwhile as it's edge-triggered: */ - if (nmi_watchdog_tick(regs, reason)) - return; - if (!do_nmi_callback(regs, cpu)) -#endif /* !CONFIG_LOCKUP_DETECTOR */ - unknown_nmi_error(reason, regs); -#else - unknown_nmi_error(reason, regs); + reassert_nmi(); #endif - + 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 @@ -446,14 +445,12 @@ do_nmi(struct pt_regs *regs, long error_code) void stop_nmi(void) { - acpi_nmi_disable(); ignore_nmis++; } void restart_nmi(void) { ignore_nmis--; - acpi_nmi_enable(); } /* May run on IST stack. */ |