x86: use raw locks during oopses

Don't want any lockdep or other fragile machinery to run during oopses.
Use raw spinlocks directly for oops locking.
Also disables irq flag tracing there.

[ tglx: arch/x86 adaptation ]

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 7 insertions, 9 deletions

diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
index b4a9b3db1994..df690c3fa458 100644
--- a/arch/x86/kernel/traps_64.c
+++ b/arch/x86/kernel/traps_64.c
@@ -462,7 +462,7 @@ void out_of_line_bug(void)
 EXPORT_SYMBOL(out_of_line_bug);
 #endif
 
-static DEFINE_SPINLOCK(die_lock);
+static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
 static int die_owner = -1;
 static unsigned int die_nest_count;
 
@@ -474,13 +474,13 @@ unsigned __kprobes long oops_begin(void)
         oops_enter();
 
         /* racy, but better than risking deadlock. */
-        local_irq_save(flags);
+        raw_local_irq_save(flags);
         cpu = smp_processor_id();
-        if (!spin_trylock(&die_lock)) { 
+        if (!__raw_spin_trylock(&die_lock)) {
                 if (cpu == die_owner) 
                         /* nested oops. should stop eventually */;
                 else
-                        spin_lock(&die_lock);
+                        __raw_spin_lock(&die_lock);
         }
         die_nest_count++;
         die_owner = cpu;
@@ -494,12 +494,10 @@ void __kprobes oops_end(unsigned long flags)
         die_owner = -1;
         bust_spinlocks(0);
         die_nest_count--;
-        if (die_nest_count)
-                /* We still own the lock */
-                local_irq_restore(flags);
-        else
+        if (!die_nest_count)
                 /* Nest count reaches zero, release the lock. */
-                spin_unlock_irqrestore(&die_lock, flags);
+                __raw_spin_unlock(&die_lock);
+        raw_local_irq_restore(flags);
         if (panic_on_oops)
                 panic("Fatal exception");
         oops_exit();