From: "tip-bot2 for Thomas Gleixner" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: sched/core] sched: Move kprobes cleanup out of finish_task_switch()
Date: Fri, 01 Oct 2021 15:05:50 -0000 [thread overview]
Message-ID: <163310075007.25758.9589191273271590112.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20210928122411.537994026@linutronix.de>
The following commit has been merged into the sched/core branch of tip:
Commit-ID: d428aac9dff0a0d217f3449884ac958dbf3f232b
Gitweb: https://git.kernel.org/tip/d428aac9dff0a0d217f3449884ac958dbf3f232b
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 28 Sep 2021 14:24:28 +02:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 01 Oct 2021 13:58:07 +02:00
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
---
kernel/exit.c | 2 ++
kernel/kprobes.c | 8 ++++----
kernel/sched/core.c | 6 ------
3 files changed, 6 insertions(+), 10 deletions(-)
diff --git a/kernel/exit.c b/kernel/exit.c
index fd1c041..df281b4 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>
@@ -169,6 +170,7 @@ 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 745f08f..89194e5 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1256,10 +1256,10 @@ 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 8d844d0..8e49b17 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4783,12 +4783,6 @@ 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);
next prev parent reply other threads:[~2021-10-01 15:06 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-28 12:24 [patch 0/5] sched: Miscellaneous RT related tweaks Thomas Gleixner
2021-09-28 12:24 ` [patch 1/5] sched: Limit the number of task migrations per batch on RT Thomas Gleixner
2021-10-01 15:05 ` [tip: sched/core] " tip-bot2 for Thomas Gleixner
2021-10-05 14:11 ` tip-bot2 for Thomas Gleixner
2021-09-28 12:24 ` [patch 2/5] sched: Disable TTWU_QUEUE " Thomas Gleixner
2021-10-01 15:05 ` [tip: sched/core] " tip-bot2 for Thomas Gleixner
2021-10-05 14:11 ` tip-bot2 for Thomas Gleixner
2021-09-28 12:24 ` [patch 3/5] sched: Move kprobes cleanup out of finish_task_switch() Thomas Gleixner
2021-10-01 15:05 ` tip-bot2 for Thomas Gleixner [this message]
2021-10-05 14:11 ` [tip: sched/core] " tip-bot2 for Thomas Gleixner
2021-09-28 12:24 ` [patch 4/5] sched: Delay task stack freeing on RT Thomas Gleixner
2021-09-29 11:54 ` Peter Zijlstra
2021-10-01 16:12 ` Andy Lutomirski
2021-10-01 17:24 ` Thomas Gleixner
2021-10-01 18:48 ` Andy Lutomirski
2021-10-01 19:02 ` Andy Lutomirski
2021-10-01 20:54 ` Thomas Gleixner
2021-09-28 12:24 ` [patch 5/5] sched: Move mmdrop to RCU " Thomas Gleixner
2021-09-29 12:02 ` Peter Zijlstra
2021-09-29 13:05 ` Thomas Gleixner
2021-10-01 15:05 ` [tip: sched/core] " tip-bot2 for Thomas Gleixner
2021-10-05 14:11 ` tip-bot2 for Thomas Gleixner
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