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Diffstat (limited to 'arch/x86/kernel/crash.c')
-rw-r--r--arch/x86/kernel/crash.c86
1 files changed, 25 insertions, 61 deletions
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 26855381790..c689d19e35a 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -26,37 +26,21 @@
#include <linux/kdebug.h>
#include <asm/smp.h>
#include <asm/reboot.h>
+#include <asm/virtext.h>
#include <mach_ipi.h>
-/* This keeps a track of which one is crashing cpu. */
-static int crashing_cpu;
#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
-static atomic_t waiting_for_crash_ipi;
-static int crash_nmi_callback(struct notifier_block *self,
- unsigned long val, void *data)
+static void kdump_nmi_callback(int cpu, struct die_args *args)
{
struct pt_regs *regs;
#ifdef CONFIG_X86_32
struct pt_regs fixed_regs;
#endif
- int cpu;
- if (val != DIE_NMI_IPI)
- return NOTIFY_OK;
-
- regs = ((struct die_args *)data)->regs;
- cpu = raw_smp_processor_id();
-
- /* Don't do anything if this handler is invoked on crashing cpu.
- * Otherwise, system will completely hang. Crashing cpu can get
- * an NMI if system was initially booted with nmi_watchdog parameter.
- */
- if (cpu == crashing_cpu)
- return NOTIFY_STOP;
- local_irq_disable();
+ regs = args->regs;
#ifdef CONFIG_X86_32
if (!user_mode_vm(regs)) {
@@ -65,54 +49,28 @@ static int crash_nmi_callback(struct notifier_block *self,
}
#endif
crash_save_cpu(regs, cpu);
- disable_local_APIC();
- atomic_dec(&waiting_for_crash_ipi);
- /* Assume hlt works */
- halt();
- for (;;)
- cpu_relax();
- return 1;
-}
+ /* Disable VMX or SVM if needed.
+ *
+ * We need to disable virtualization on all CPUs.
+ * Having VMX or SVM enabled on any CPU may break rebooting
+ * after the kdump kernel has finished its task.
+ */
+ cpu_emergency_vmxoff();
+ cpu_emergency_svm_disable();
-static void smp_send_nmi_allbutself(void)
-{
- cpumask_t mask = cpu_online_map;
- cpu_clear(safe_smp_processor_id(), mask);
- if (!cpus_empty(mask))
- send_IPI_mask(mask, NMI_VECTOR);
+ disable_local_APIC();
}
-static struct notifier_block crash_nmi_nb = {
- .notifier_call = crash_nmi_callback,
-};
-
-static void nmi_shootdown_cpus(void)
+static void kdump_nmi_shootdown_cpus(void)
{
- unsigned long msecs;
-
- atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
- /* Would it be better to replace the trap vector here? */
- if (register_die_notifier(&crash_nmi_nb))
- return; /* return what? */
- /* Ensure the new callback function is set before sending
- * out the NMI
- */
- wmb();
-
- smp_send_nmi_allbutself();
-
- msecs = 1000; /* Wait at most a second for the other cpus to stop */
- while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
- mdelay(1);
- msecs--;
- }
+ nmi_shootdown_cpus(kdump_nmi_callback);
- /* Leave the nmi callback set */
disable_local_APIC();
}
+
#else
-static void nmi_shootdown_cpus(void)
+static void kdump_nmi_shootdown_cpus(void)
{
/* There are no cpus to shootdown */
}
@@ -131,9 +89,15 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
/* The kernel is broken so disable interrupts */
local_irq_disable();
- /* Make a note of crashing cpu. Will be used in NMI callback.*/
- crashing_cpu = safe_smp_processor_id();
- nmi_shootdown_cpus();
+ kdump_nmi_shootdown_cpus();
+
+ /* Booting kdump kernel with VMX or SVM enabled won't work,
+ * because (among other limitations) we can't disable paging
+ * with the virt flags.
+ */
+ cpu_emergency_vmxoff();
+ cpu_emergency_svm_disable();
+
lapic_shutdown();
#if defined(CONFIG_X86_IO_APIC)
disable_IO_APIC();