From patchwork Tue Apr 25 18:49:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 87514 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b0ea:0:b0:3b6:4342:cba0 with SMTP id b10csp3605029vqo; Tue, 25 Apr 2023 11:50:47 -0700 (PDT) X-Google-Smtp-Source: AKy350ZRyjr1fwa2QRZHr+tNpy6YWtb1H49LD1PLpbPh93v6FOa9pDplxShMtzAN+Eh7e1TrwW1h X-Received: by 2002:a05:6a00:23c9:b0:63f:cfd:5d10 with SMTP id g9-20020a056a0023c900b0063f0cfd5d10mr22563824pfc.8.1682448646758; Tue, 25 Apr 2023 11:50:46 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1682448646; cv=none; d=google.com; s=arc-20160816; b=xhRBZWtaNo8gPxFmb3Bcz3UcGKJuBGqEQQ+7VpCEWwtGjTDNTzwVtqGwBAZIY4xLw7 p9T3IcIp5dAdwc0Id1l7u8WL+UYhx6tJNHCFsVMLC+uLLXB7OWwhaEPq6GF6IR8ldYHl Y4iQ4dCDk6HeieyQbLzYj9v/VOwd8e8Fj9z9nU++JTY2sJjqvMtBzq+poNVGawtq7DL2 +ggwrhYj+OTpgfK7blFRGeeZRoH6OwzenmM4oOr6h4UXHO9hBsT+oAxzxPn7o4Kk5CQ8 lNQ9dsjEHaJ2Xvt/ZV9wpNSahIOZv0nSDujXp6ZKWQpJaYobDYqgAEWZxhH3/L6G80Uq n3Lw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:date:mime-version:references:subject:cc:to:from :dkim-signature:dkim-signature:message-id; bh=DCSkADwrTdaHqprFhioGbr3aS4AKwjAJNkVmh+N50Zw=; b=hstrOojHuGeEzeQASZ/nsFYi/eGtFMX8AdH16mg3azFf2cym6rpYJvwum7ddhhSaLB a0AKxjB94/p4D2F4nlr7ymO1OFv3tTZ4LmYrFzl02gAAgXNfz/rBDzZo7XmehtWT0DWc glu4NPDxjX2a0zyzi9r5oN9DGnt4lfSZXu2VehZPwjn7C+WMLcdFof5makAiS6/5kNMH jf2FOYxh11yntYgAtQtkYpSxbog3OdF9EgxZMlff2Dam7IeGx4e5FuT0cwTcCpiusOJg lC9hgSV8Ksyfx3NJuSFG6uD+iw91dmvNIPm/2KLQg1PKkHBE+2gg+MHNaNONLM8/w08v JaBw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b=VTZY1lnd; dkim=neutral (no key) header.i=@linutronix.de; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=linutronix.de Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id bk13-20020a056a02028d00b00528513d5e9dsi4480922pgb.109.2023.04.25.11.50.31; Tue, 25 Apr 2023 11:50:46 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b=VTZY1lnd; dkim=neutral (no key) header.i=@linutronix.de; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=linutronix.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234742AbjDYStb (ORCPT + 99 others); Tue, 25 Apr 2023 14:49:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234707AbjDYStM (ORCPT ); Tue, 25 Apr 2023 14:49:12 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B96117A12 for ; Tue, 25 Apr 2023 11:49:08 -0700 (PDT) Message-ID: <20230425183313.196462644@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1682448547; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=DCSkADwrTdaHqprFhioGbr3aS4AKwjAJNkVmh+N50Zw=; b=VTZY1lnd2NAe21P++0IRfRXClWQh2YO96ayeMriJurbq5WD0fXi1OND56EjzdwXo+cu0// WRbBXLNioZN/7XNoQgU/61vTEVdgIZBd+fxY9Xd0iH/CUCn9+21keYHwMfz/Q3vFbVYGEk lK6Il3hdAZPbp8Y1ADQrYXY5m2IB2K8iXHQKvijp1nKsyLcU7cl/YULzlsNyU+EPYTUGRQ 1OhDYHCgTGHaO7kQAPWQcjT9CyeRXDH/128ap7dS6yj99+35exBbwlBELtitP5r4igJx7a YMRGP8QgZr2d/HUifuzSk/mhcHGaL4qL5M9akO2yRM844LEP0KQl7BGvEqvcFA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1682448547; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=DCSkADwrTdaHqprFhioGbr3aS4AKwjAJNkVmh+N50Zw=; b=xtbsT/23TQ81TQI3kADGd7xmm0ZozIe54Bf4xIbRKBneEoMlpD/TGc4UIlh/6a4/e0e5SG 04I9wZdGsJVrkmDA== From: Thomas Gleixner To: LKML Cc: Frederic Weisbecker , Anna-Maria Behnsen , Peter Zijlstra , Sebastian Siewior , syzbot+5c54bd3eb218bb595aa9@syzkaller.appspotmail.com, Dmitry Vyukov , Michael Kerrisk Subject: [patch 07/20] posix-timers: Set k_itimer::it_signal to NULL on exit() References: <20230425181827.219128101@linutronix.de> MIME-Version: 1.0 Date: Tue, 25 Apr 2023 20:49:06 +0200 (CEST) X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_PASS,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED 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?1764175272121174520?= X-GMAIL-MSGID: =?utf-8?q?1764175272121174520?= Technically it's not required to set k_itimer::it_signal to NULL on exit() because there is no other thread anymore which could lookup the timer concurrently. Set it to NULL for consistency sake and add a comment to that effect. Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker --- kernel/time/posix-timers.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -1107,6 +1107,14 @@ static void itimer_delete(struct k_itime } list_del(&timer->list); + /* + * Setting timer::it_signal to NULL is technically not required + * here as nothing can access the timer anymore legitimately via + * the hash table. Set it to NULL nevertheless so that all deletion + * paths are consistent. + */ + WRITE_ONCE(timer->it_signal, NULL); + spin_unlock_irqrestore(&timer->it_lock, flags); release_posix_timer(timer, IT_ID_SET); }