From: Sebastian Andrzej Siewior Date: Mon, 21 Nov 2016 19:31:08 +0100 Subject: [PATCH 108/342] kernel/sched: move stack + kprobe clean up to __put_task_struct() Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=3dd0ebab3223ff2fcf7a12a1ee3bf1ad46d17b85 There is no need to free the stack before the task struct (except for reasons mentioned in commit 68f24b08ee89 ("sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK")). This also comes handy on -RT because we can't free memory in preempt disabled region. Cc: stable-rt@vger.kernel.org #for kprobe_flush_task() Signed-off-by: Sebastian Andrzej Siewior --- kernel/fork.c | 10 ++++++++++ kernel/sched/core.c | 9 --------- 2 files changed, 10 insertions(+), 9 deletions(-) diff --git a/kernel/fork.c b/kernel/fork.c index 114ff9724b02..efe690af29f1 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include #include @@ -698,6 +699,15 @@ void __put_task_struct(struct task_struct *tsk) WARN_ON(atomic_read(&tsk->usage)); WARN_ON(tsk == current); + /* + * Remove function-return probe instances associated with this + * task and put them back on the free list. + */ + kprobe_flush_task(tsk); + + /* Task is done with its stack. */ + put_task_stack(tsk); + cgroup_free(tsk); task_numa_free(tsk, true); security_task_free(tsk); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 676b9b213991..089779e18440 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2746,15 +2746,6 @@ static struct rq *finish_task_switch(struct task_struct *prev) if (prev->sched_class->task_dead) prev->sched_class->task_dead(prev); - /* - * Remove function-return probe instances associated with this - * task and put them back on the free list. - */ - kprobe_flush_task(prev); - - /* Task is done with its stack. */ - put_task_stack(prev); - put_task_struct(prev); }