diff options
| -rw-r--r-- | arch/x86/kernel/dumpstack_32.c | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c index a29b88ffa34..7c7d691b32b 100644 --- a/arch/x86/kernel/dumpstack_32.c +++ b/arch/x86/kernel/dumpstack_32.c @@ -289,21 +289,24 @@ static unsigned int die_nest_count; unsigned __kprobes long oops_begin(void) { + int cpu; unsigned long flags; oops_enter(); - if (die_owner != raw_smp_processor_id()) { - console_verbose(); - raw_local_irq_save(flags); - __raw_spin_lock(&die_lock); - die_owner = smp_processor_id(); - die_nest_count = 0; - bust_spinlocks(1); - } else { - raw_local_irq_save(flags); + /* racy, but better than risking deadlock. */ + raw_local_irq_save(flags); + cpu = smp_processor_id(); + if (!__raw_spin_trylock(&die_lock)) { + if (cpu == die_owner) + /* nested oops. should stop eventually */; + else + __raw_spin_lock(&die_lock); } die_nest_count++; + die_owner = cpu; + console_verbose(); + bust_spinlocks(1); return flags; } @@ -315,13 +318,15 @@ void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr) bust_spinlocks(0); die_owner = -1; add_taint(TAINT_DIE); - __raw_spin_unlock(&die_lock); + die_nest_count--; + if (!die_nest_count) + /* Nest count reaches zero, release the lock. */ + __raw_spin_unlock(&die_lock); raw_local_irq_restore(flags); - oops_exit(); + if (!signr) return; - if (in_interrupt()) panic("Fatal exception in interrupt"); if (panic_on_oops) |