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arm64: traps: disable irq in die() 

In current die(), the irq is disabled for __die() handle, not
including the possible panic() handling. Since the log in __die()
can take several hundreds ms, new irq might come and interrupt
current die().

If the process calling die() holds some critical resource, and some
other process scheduled later also needs it, then it would deadlock.
The first panic will not be executed.

So here disable irq for the whole flow of die().

Signed-off-by: Qiao Zhou <qiaozhou@asrmicro.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Qiao Zhou 2017-07-07 17:29:34 +08:00 committed by Will Deacon
parent 32fb5d73c9
commit 6f44a0bacb
1 changed files with 6 additions and 2 deletions
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8
arch/arm64/kernel/traps.c
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@ -274,10 +274,12 @@ static DEFINE_RAW_SPINLOCK(die_lock);
void die(const char *str, struct pt_regs *regs, int err)
{
int ret;
unsigned long flags;
raw_spin_lock_irqsave(&die_lock, flags);
oops_enter();
raw_spin_lock_irq(&die_lock);
console_verbose();
bust_spinlocks(1);
ret = __die(str, err, regs);
@ -287,13 +289,15 @@ void die(const char *str, struct pt_regs *regs, int err)
bust_spinlocks(0);
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
raw_spin_unlock_irq(&die_lock);
oops_exit();
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception");
raw_spin_unlock_irqrestore(&die_lock, flags);
if (ret != NOTIFY_STOP)
do_exit(SIGSEGV);
}