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Diffstat (limited to 'arch/i386/kernel/crash.c')
-rw-r--r--arch/i386/kernel/crash.c36
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(&regs);
+
+ if (saved_regs)
+ crash_setup_regs(&regs, saved_regs);
+ else
+ crash_get_current_regs(&regs);
crash_save_this_cpu(&regs, 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);
}