x86: Only call smp_processor_id in non-preempt cases

There are some paths that walk the die_chain with preemption on.
Make sure we are in an NMI call before we start doing anything.

This was triggered by do_general_protection calling notify_die
with DIE_GPF.

Reported-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Don Zickus <dzickus@redhat.com>
LKML-Reference: <1294198689-15447-1-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Don Zickus 2011-01-04 22:38:07 -05:00 committed by Ingo Molnar
parent aef1b9cef7
commit 9ab181fa9f

View File

@ -51,7 +51,7 @@ arch_trigger_all_cpu_backtrace_handler(struct notifier_block *self,
{ {
struct die_args *args = __args; struct die_args *args = __args;
struct pt_regs *regs; struct pt_regs *regs;
int cpu = smp_processor_id(); int cpu;
switch (cmd) { switch (cmd) {
case DIE_NMI: case DIE_NMI:
@ -63,6 +63,7 @@ arch_trigger_all_cpu_backtrace_handler(struct notifier_block *self,
} }
regs = args->regs; regs = args->regs;
cpu = smp_processor_id();
if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) { if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED; static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED;