6 files changed, 45 insertions, 16 deletions

diff --git a/arch/i386/kernel/crash.c b/arch/i386/kernel/crash.c
index a021681d21f8..8bdb4b6af0ff 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);
 }
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 207ea8ba7169..e458463ebc05 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -27,6 +27,7 @@
 #include <linux/ptrace.h>
 #include <linux/utsname.h>
 #include <linux/kprobes.h>
+#include <linux/kexec.h>
 
 #ifdef CONFIG_EISA
 #include <linux/ioport.h>
@@ -294,6 +295,9 @@ bug:
         printk("Kernel BUG\n");
 }
 
+/* This is gone through when something in the kernel
+ * has done something bad and is about to be terminated.
+*/
 void die(const char * str, struct pt_regs * regs, long err)
 {
         static struct {
@@ -341,6 +345,10 @@ void die(const char * str, struct pt_regs * regs, long err)
         bust_spinlocks(0);
         die.lock_owner = -1;
         spin_unlock_irq(&die.lock);
+
+        if (kexec_should_crash(current))
+                crash_kexec(regs);
+
         if (in_interrupt())
                 panic("Fatal exception in interrupt");
 
@@ -570,6 +578,15 @@ void die_nmi (struct pt_regs *regs, const char *msg)
         console_silent();
         spin_unlock(&nmi_print_lock);
         bust_spinlocks(0);
+
+        /* If we are in kernel we are probably nested up pretty bad
+         * and might aswell get out now while we still can.
+        */
+        if (!user_mode(regs)) {
+                current->thread.trap_no = 2;
+                crash_kexec(regs);
+        }
+
         do_exit(SIGSEGV);
 }
 
diff --git a/arch/ppc/kernel/machine_kexec.c b/arch/ppc/kernel/machine_kexec.c
index 435ad9ea0a83..b82535357d6d 100644
--- a/arch/ppc/kernel/machine_kexec.c
+++ b/arch/ppc/kernel/machine_kexec.c
@@ -34,7 +34,7 @@ void machine_shutdown(void)
         }
 }
 
-void machine_crash_shutdown(void)
+void machine_crash_shutdown(struct pt_regs *regs)
 {
         if (ppc_md.machine_crash_shutdown) {
                 ppc_md.machine_crash_shutdown();
diff --git a/arch/ppc64/kernel/machine_kexec.c b/arch/ppc64/kernel/machine_kexec.c
index 217965d60a45..06b25b59c8a8 100644
--- a/arch/ppc64/kernel/machine_kexec.c
+++ b/arch/ppc64/kernel/machine_kexec.c
@@ -34,7 +34,7 @@ note_buf_t crash_notes[NR_CPUS];
  * and if what it will achieve. Letting it be now to compile the code
  * in generic kexec environment
  */
-void machine_crash_shutdown(void)
+void machine_crash_shutdown(struct pt_regs *regs)
 {
         /* do nothing right now */
         /* smp_relase_cpus() if we want smp on panic kernel */
diff --git a/arch/s390/kernel/crash.c b/arch/s390/kernel/crash.c
index db38283c1f27..7bd169c58b0c 100644
--- a/arch/s390/kernel/crash.c
+++ b/arch/s390/kernel/crash.c
@@ -12,6 +12,6 @@
 
 note_buf_t crash_notes[NR_CPUS];
 
-void machine_crash_shutdown(void)
+void machine_crash_shutdown(struct pt_regs *regs)
 {
 }
diff --git a/arch/x86_64/kernel/crash.c b/arch/x86_64/kernel/crash.c
index 6183bcb85257..d7fa4248501c 100644
--- a/arch/x86_64/kernel/crash.c
+++ b/arch/x86_64/kernel/crash.c
@@ -22,7 +22,7 @@
 
 note_buf_t crash_notes[NR_CPUS];
 
-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.