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-rw-r--r--arch/Kconfig2
-rw-r--r--kernel/kprobes.c14
2 files changed, 9 insertions, 7 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index 1aafb4efbb51..f75c8e8a229b 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -90,7 +90,7 @@ config STATIC_KEYS_SELFTEST
config OPTPROBES
def_bool y
depends on KPROBES && HAVE_OPTPROBES
- depends on !PREEMPT
+ select TASKS_RCU if PREEMPT
config KPROBES_ON_FTRACE
def_bool y
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 15fba7fe57c8..a8fc1492b308 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -573,13 +573,15 @@ static void kprobe_optimizer(struct work_struct *work)
do_unoptimize_kprobes();
/*
- * Step 2: Wait for quiesence period to ensure all running interrupts
- * are done. Because optprobe may modify multiple instructions
- * there is a chance that Nth instruction is interrupted. In that
- * case, running interrupt can return to 2nd-Nth byte of jump
- * instruction. This wait is for avoiding it.
+ * Step 2: Wait for quiesence period to ensure all potentially
+ * preempted tasks to have normally scheduled. Because optprobe
+ * may modify multiple instructions, there is a chance that Nth
+ * instruction is preempted. In that case, such tasks can return
+ * to 2nd-Nth byte of jump instruction. This wait is for avoiding it.
+ * Note that on non-preemptive kernel, this is transparently converted
+ * to synchronoze_sched() to wait for all interrupts to have completed.
*/
- synchronize_sched();
+ synchronize_rcu_tasks();
/* Step 3: Optimize kprobes after quiesence period */
do_optimize_kprobes();