diff options
| -rw-r--r-- | kernel/events/core.c | 7 | ||||
| -rw-r--r-- | kernel/exit.c | 17 |
2 files changed, 16 insertions, 8 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 7b97be4ed9d0..ecae7c7f895b 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6219,6 +6219,10 @@ perf_sample_ustack_size(u16 stack_size, u16 header_size, if (!regs) return 0; + /* No mm, no stack, no dump. */ + if (!current->mm) + return 0; + /* * Check if we fit in with the requested stack size into the: * - TASK_SIZE @@ -6687,6 +6691,9 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs) const u32 max_stack = event->attr.sample_max_stack; struct perf_callchain_entry *callchain; + if (!current->mm) + user = false; + if (!kernel && !user) return &__empty_callchain; diff --git a/kernel/exit.c b/kernel/exit.c index 56d3a099825f..8cb4a82c4ed3 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -844,6 +844,15 @@ void __noreturn do_exit(long code) tsk->exit_code = code; taskstats_exit(tsk, group_dead); + /* + * Since sampling can touch ->mm, make sure to stop everything before we + * tear it down. + * + * Also flushes inherited counters to the parent - before the parent + * gets woken up by child-exit notifications. + */ + perf_event_exit_task(tsk); + exit_mm(); if (group_dead) @@ -861,14 +870,6 @@ void __noreturn do_exit(long code) exit_thread(tsk); exit_umh(tsk); - /* - * Flush inherited counters to the parent - before the parent - * gets woken up by child-exit notifications. - * - * because of cgroup mode, must be called before cgroup_exit() - */ - perf_event_exit_task(tsk); - sched_autogroup_exit_task(tsk); cgroup_exit(tsk); |