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authorQiao Zhou <qiaozhou@asrmicro.com>2017-07-07 17:29:34 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-03 06:23:19 +0200
commite86206bd875877825a3f0328adcc332f9bdf8ef1 (patch)
tree53a888927280f184b43af6e6861e237621489c88 /arch/arm64
parenta3fbab100127b99b82e13f1b9ad8ec91c9c6ed56 (diff)
arm64: traps: disable irq in die()
commit 6f44a0bacb79a03972c83759711832b382b1b8ac upstream. 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> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64')
-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 5d270ca76aec..6b4579e07aa2 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -239,10 +239,12 @@ void die(const char *str, struct pt_regs *regs, int err)
{
struct thread_info *thread = current_thread_info();
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, thread, regs);
@@ -252,13 +254,15 @@ 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);
}