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>

diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c
index 746fad2..3f02e0f 100644 (file)
--- a/arch/x86/kernel/traps_32.c
+++ b/arch/x86/kernel/traps_32.c
@@ -350,11 +350,11 @@ int is_valid_bugaddr(unsigned long eip)
 void die(const char * str, struct pt_regs * regs, long err)
 {
        static struct {
-               spinlock_t lock;
+               raw_spinlock_t lock;
                u32 lock_owner;
                int lock_owner_depth;
        } die = {
-               .lock =                 __SPIN_LOCK_UNLOCKED(die.lock),
+               .lock =                 __RAW_SPIN_LOCK_UNLOCKED,
                .lock_owner =           -1,
                .lock_owner_depth =     0
        };
@@ -365,13 +365,14 @@ void die(const char * str, struct pt_regs * regs, long err)
 
        if (die.lock_owner != raw_smp_processor_id()) {
                console_verbose();
-               spin_lock_irqsave(&die.lock, flags);
+               __raw_spin_lock(&die.lock);
+               raw_local_save_flags(flags);
                die.lock_owner = smp_processor_id();
                die.lock_owner_depth = 0;
                bust_spinlocks(1);
        }
        else
-               local_save_flags(flags);
+               raw_local_save_flags(flags);
 
        if (++die.lock_owner_depth < 3) {
                unsigned long esp;
@@ -415,7 +416,8 @@ void die(const char * str, struct pt_regs * regs, long err)
        bust_spinlocks(0);
        die.lock_owner = -1;
        add_taint(TAINT_DIE);
-       spin_unlock_irqrestore(&die.lock, flags);
+       __raw_spin_unlock(&die.lock);
+       raw_local_irq_restore(flags);
 
        if (!regs)
                return;

diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
index b4a9b3d..df690c3 100644 (file)
--- 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();