diff options
Diffstat (limited to 'arch/i386/kernel/crash.c')
-rw-r--r-- | arch/i386/kernel/crash.c | 36 |
1 files changed, 24 insertions, 12 deletions
diff --git a/arch/i386/kernel/crash.c b/arch/i386/kernel/crash.c index a021681..8bdb4b6 100644 --- a/arch/i386/kernel/crash.c +++ b/arch/i386/kernel/crash.c @@ -100,12 +100,31 @@ static void crash_get_current_regs(struct pt_regs *regs) regs->eip = (unsigned long)current_text_addr(); } -static void crash_save_self(void) +/* CPU does not save ss and esp on stack if execution is already + * running in kernel mode at the time of NMI occurrence. This code + * fixes it. + */ +static void crash_setup_regs(struct pt_regs *newregs, struct pt_regs *oldregs) +{ + memcpy(newregs, oldregs, sizeof(*newregs)); + newregs->esp = (unsigned long)&(oldregs->esp); + __asm__ __volatile__("xorl %eax, %eax;"); + __asm__ __volatile__ ("movw %%ss, %%ax;" :"=a"(newregs->xss)); +} + +/* We may have saved_regs from where the error came from + * or it is NULL if via a direct panic(). + */ +static void crash_save_self(struct pt_regs *saved_regs) { struct pt_regs regs; int cpu; cpu = smp_processor_id(); - crash_get_current_regs(®s); + + if (saved_regs) + crash_setup_regs(®s, saved_regs); + else + crash_get_current_regs(®s); crash_save_this_cpu(®s, cpu); } @@ -124,15 +143,8 @@ static int crash_nmi_callback(struct pt_regs *regs, int cpu) return 1; local_irq_disable(); - /* CPU does not save ss and esp on stack if execution is already - * running in kernel mode at the time of NMI occurrence. This code - * fixes it. - */ if (!user_mode(regs)) { - memcpy(&fixed_regs, regs, sizeof(*regs)); - fixed_regs.esp = (unsigned long)&(regs->esp); - __asm__ __volatile__("xorl %eax, %eax;"); - __asm__ __volatile__ ("movw %%ss, %%ax;" :"=a"(fixed_regs.xss)); + crash_setup_regs(&fixed_regs, regs); regs = &fixed_regs; } crash_save_this_cpu(regs, cpu); @@ -184,7 +196,7 @@ static void nmi_shootdown_cpus(void) } #endif -void machine_crash_shutdown(void) +void machine_crash_shutdown(struct pt_regs *regs) { /* This function is only called after the system * has paniced or is otherwise in a critical state. @@ -204,5 +216,5 @@ void machine_crash_shutdown(void) #if defined(CONFIG_X86_IO_APIC) disable_IO_APIC(); #endif - crash_save_self(); + crash_save_self(regs); } |