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authorQiao Zhou <qiaozhou@asrmicro.com>2017-07-07 17:29:34 +0800
committerWill Deacon <will.deacon@arm.com>2017-07-20 10:21:06 +0100
commit6f44a0bacb79a03972c83759711832b382b1b8ac (patch)
tree1b27e981920b688e44df86722d3903e6e93cdc5b
parent32fb5d73c98b079e7c815b62e9d88a39ff8ce509 (diff)
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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>
-rw-r--r--arch/arm64/kernel/traps.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index c7c7088097be..d48f47080213 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -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);
}