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| author | Thomas Gleixner <tglx@linutronix.de> | 2021-09-28 14:24:28 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-10-05 15:52:14 +0200 |
| commit | 670721c7bd2a6e16e40db29b2707a27bdecd6928 (patch) | |
| tree | 27ead0ffba4532ed1e500925b7d9b1783bd6687f | |
| parent | 539fbb5be0da56ffa1434b4f56521a0522bd1d61 (diff) | |
| download | linux-670721c7bd2a6e16e40db29b2707a27bdecd6928.tar.gz linux-670721c7bd2a6e16e40db29b2707a27bdecd6928.tar.bz2 linux-670721c7bd2a6e16e40db29b2707a27bdecd6928.zip | |
sched: Move kprobes cleanup out of finish_task_switch()
Doing cleanups in the tail of schedule() is a latency punishment for the
incoming task. The point of invoking kprobes_task_flush() for a dead task
is that the instances are returned and cannot leak when __schedule() is
kprobed.
Move it into the delayed cleanup.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210928122411.537994026@linutronix.de
| -rw-r--r-- | kernel/exit.c | 2 | ||||
| -rw-r--r-- | kernel/kprobes.c | 8 | ||||
| -rw-r--r-- | kernel/sched/core.c | 6 |
3 files changed, 6 insertions, 10 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 91a43e57a32e..63851320ae73 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -64,6 +64,7 @@ #include <linux/rcuwait.h> #include <linux/compat.h> #include <linux/io_uring.h> +#include <linux/kprobes.h> #include <linux/uaccess.h> #include <asm/unistd.h> @@ -168,6 +169,7 @@ static void delayed_put_task_struct(struct rcu_head *rhp) { struct task_struct *tsk = container_of(rhp, struct task_struct, rcu); + kprobe_flush_task(tsk); perf_event_delayed_put(tsk); trace_sched_process_free(tsk); put_task_struct(tsk); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 790a573bbe00..9a38e7581a5c 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1250,10 +1250,10 @@ void kprobe_busy_end(void) } /* - * This function is called from finish_task_switch when task tk becomes dead, - * so that we can recycle any function-return probe instances associated - * with this task. These left over instances represent probed functions - * that have been called but will never return. + * This function is called from delayed_put_task_struct() when a task is + * dead and cleaned up to recycle any function-return probe instances + * associated with this task. These left over instances represent probed + * functions that have been called but will never return. */ void kprobe_flush_task(struct task_struct *tk) { diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 749284fc3c1f..e33b03c2bb9a 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4846,12 +4846,6 @@ 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); |