Linus, Please pull the latest perf/urgent git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-2020-10-11 # HEAD: 6d6b8b9f4fceab7266ca03d194f60ec72bd4b654 perf: Fix task_function_call() error handling Fix an error handling bug that can cause a lockup if a CPU is offline. (doh ...) Thanks, Ingo ------------------> Kajol Jain (1): perf: Fix task_function_call() error handling kernel/events/core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 7ed5248f0445..e8bf92202542 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -99,7 +99,7 @@ static void remote_function(void *data) * retry due to any failures in smp_call_function_single(), such as if the * task_cpu() goes offline concurrently. * - * returns @func return value or -ESRCH when the process isn't running + * returns @func return value or -ESRCH or -ENXIO when the process isn't running */ static int task_function_call(struct task_struct *p, remote_function_f func, void *info) @@ -115,7 +115,8 @@ task_function_call(struct task_struct *p, remote_function_f func, void *info) for (;;) { ret = smp_call_function_single(task_cpu(p), remote_function, &data, 1); - ret = !ret ? data.ret : -EAGAIN; + if (!ret) + ret = data.ret; if (ret != -EAGAIN) break;