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authorThomas Gleixner <tglx@linutronix.de>2020-08-26 01:36:07 +0200
committerThomas Gleixner <tglx@linutronix.de>2020-08-26 01:36:07 +0200
commitceb2465c51195967f11f6507538579816ac67cb8 (patch)
treeeab534b1062608e36a7b54ccc7be693625f235b8 /kernel/task_work.c
parentf107cee94ba4d2c7357fde59a1d84346c73d4958 (diff)
parent821fc9e261f3af235752f46e59084467cfd440c4 (diff)
Merge tag 'irqchip-fixes-5.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgentirq-urgent-2020-08-30
Pull irqchip fixes from Marc Zyngier: - Revert the wholesale conversion to platform drivers of the pdc, sysirq and cirq drivers, as it breaks a number of platforms even when the driver is built-in (probe ordering bites you). - Prevent interrupt from being lost with the STM32 exti driver - Fix wake-up interrupts for the MIPS Ingenic driver - Fix an embarassing typo in the new module helpers, leading to the probe failing most of the time - The promised TI firmware rework that couldn't make it into the merge window due to a very badly managed set of dependencies
Diffstat (limited to 'kernel/task_work.c')
-rw-r--r--kernel/task_work.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/task_work.c b/kernel/task_work.c
index 5c0848ca1287..613b2d634af8 100644
--- a/kernel/task_work.c
+++ b/kernel/task_work.c
@@ -42,7 +42,13 @@ task_work_add(struct task_struct *task, struct callback_head *work, int notify)
set_notify_resume(task);
break;
case TWA_SIGNAL:
- if (lock_task_sighand(task, &flags)) {
+ /*
+ * Only grab the sighand lock if we don't already have some
+ * task_work pending. This pairs with the smp_store_mb()
+ * in get_signal(), see comment there.
+ */
+ if (!(READ_ONCE(task->jobctl) & JOBCTL_TASK_WORK) &&
+ lock_task_sighand(task, &flags)) {
task->jobctl |= JOBCTL_TASK_WORK;
signal_wake_up(task, 0);
unlock_task_sighand(task, &flags);