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Biederman" , Geert Uytterhoeven , Stafford Horne , "Russell King (Oracle)" , Oleg Nesterov , Wander Lairson Costa , Kefeng Wang , Andrew Morton , Thomas Gleixner , Sebastian Andrzej Siewior , Andy Lutomirski , "Liam R. Howlett" , Fenghua Yu , Andrei Vagin , linux-kernel@vger.kernel.org (open list) Subject: [PATCH v2 4/4] sched/core: use put_task_struct_atomic_safe() to avoid potential splat Date: Fri, 20 Jan 2023 12:02:42 -0300 Message-Id: <20230120150246.20797-5-wander@redhat.com> In-Reply-To: <20230120150246.20797-1-wander@redhat.com> References: <20230120150246.20797-1-wander@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1755555265743039390?= X-GMAIL-MSGID: =?utf-8?q?1755555265743039390?= push_cpu_stop() is called form a context in which it must not sleep. Since push_cpu_stop() calls put_task_struct(), it potentially can sleep under PREEMPT_RT if the usage count reaches zero. Use put_task_struct_atomic_safe(0 instead to avoid this potential splat. Signed-off-by: Wander Lairson Costa Cc: Thomas Gleixner --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c437260e19b0..e5d0c66cb90c 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2565,7 +2565,7 @@ int push_cpu_stop(void *arg) raw_spin_rq_unlock(rq); raw_spin_unlock_irq(&p->pi_lock); - put_task_struct(p); + put_task_struct_atomic_safe(p); return 0; }