From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=35.89.44.37 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793116992; b=ykdlXhe4sBFvKzhGpgED1GfRBhwStL/mYVdJgnEjk5zgdjoS03yS6MlcDuhTM9hMZzpx NZZ35kY05m7nTRa3dJ0u8AqkkgD7DyCKRhqXNiWu2pLhnQhqtqp9VUC94wIdcXkPKJvpW +g0BRyby6Dgs7R2pDPCEEiuNavYnSUrZPYTR72gqwHPR8dHd3EhwTvVnR8BwIfd//RvxW on6mkGTy9xfADk8Y6dfyTMK1v21K8r5VneFC9xUGh6XA8zkJ5DGHrQbhcXGlv5om/ncxS RaLUV7d2Bb63cnKIO+Gq+EUk48GtCjnq9kpq+hD11wr++55YZtY7sC9Lagb6WYVcbfg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793116992; h=DMARC-Filter:Received:Received:X-Authority-Analysis:DKIM-Signature: Received:From:To:Cc:Subject:Date:Message-ID:X-Mailer:In-Reply-To: References:MIME-Version:Content-Transfer-Encoding:X-AntiAbuse: X-AntiAbuse:X-AntiAbuse:X-AntiAbuse:X-AntiAbuse:X-BWhitelist: X-Source-IP:X-Source-L:X-Exim-ID:X-Source:X-Source-Args:X-Source-Dir: X-Source-Sender:X-Source-Auth:X-Email-Count:X-Org:X-Source-Cap: X-Local-Domain:X-CMAE-Envelope; bh=4tf5jp72b9mmtNlArsH2jcFwIQOwqOIebwrOBPuEsBU=; b=HtsiWA93V+s591CAo9tgCOeX1jS2SK1C/FndPZjfXdaqX7r+T6SvxV4keGzV9z3vCX5t VuFw4SKDf4RkXbjHyp/Li21+nWBZiq+3M0X05V8Y5wBHJuDQ8kOibZ8vv4VkWD0XTfYU/ jHG6nH7gQHBofXijveYElqDTXFP0v+0rGdES4ojGZqd21TJPBKdd1nHicI8WEL3msBKsm cIeEXuSsh4bcXthOFusNPAmzoVqWqQpjJdM/iP951giJZfulroS9dWdQWu9kk0uaxLk1T JtmUm9tKeRrzIT2jdN6EzRwCxNEqKLWc+BT0Ags4bU2zeLL0UMAIRyRToMkmw9Y2n8g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=roeck-us.net; spf=fail smtp.mailfrom=roeck-us.net; dkim=pass header.d=roeck-us.net header.i=@roeck-us.net header.a=rsa-sha256 header.s=default header.b=LRcByQ3R; arc=none smtp.remote-ip=35.89.44.37 Received: from omta38.uswest2.a.cloudfilter.net (omta38.uswest2.a.cloudfilter.net [35.89.44.37]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 34055606A322 for ; Tue, 27 Oct 2026 16:03:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 34055606A322 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=roeck-us.net Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=roeck-us.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=roeck-us.net header.i=@roeck-us.net header.a=rsa-sha256 header.s=default header.b=LRcByQ3R Received: from eig-obgw-5007b.ext.cloudfilter.net ([10.0.29.167]) by cmsmtp with ESMTPS id LhzaxxpbBv0ndLjdlxLTQ6; Tue, 27 Oct 2026 16:03:09 +0000 Received: from 162-215-252-36.unifiedlayer.com ([208.91.199.152]) by cmsmtp with ESMTPS id Ljdjx7kWYnUK5LjdkxJNvR; Tue, 27 Oct 2026 16:03:09 +0000 X-Authority-Analysis: v=2.4 cv=ae1hnQot c=1 sm=1 tr=0 ts=6ae0cb3d a=QNED+QcLUkoL9qulTODnwA==:117 a=2cfIYNtKkjgZNaOwnGXpGw==:17 a=660iZSQnnn4A:10 a=M0FbrtG7MMAA:10 a=VwQbUJbxAAAA:8 a=_jlGtV7tAAAA:8 a=7vxEA1HKIkwBDEoJgLAA:9 a=nlm17XC03S6CtCLSeiRr:22 a=KPbNTLLc3YvdawN95zVk:22 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=roeck-us.net; s=default; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Unsubscribe-Post:List-Subscribe:List-Post:List-Owner: List-Archive; bh=4tf5jp72b9mmtNlArsH2jcFwIQOwqOIebwrOBPuEsBU=; b=LRcByQ3RMZfs cKKZfYS+ZNu6k/UXwdjqiDurL/3oS+jANaYQHSlhX/ihJ4Alu9AaA2Uhk5jLz7lot9uDVToyPDdPe Q6khd/ebnnAUGGwo3eo+X2SFhcuNA+zLKy58GEPefMkAGOgoJTvuqEf+gcGXflB8Q9fF2Yvwb2fEM daHPfVYYUQjZGlteCM6rKgp7eDp9Mr97gQYjGrT7hlfYBJMdWgCs50tiXlaf94iDoxb0K4oLSUVF0 NvyRtvDd21STaiMXEo9vd4uA+WorRw4INpXW+LD1jeOaSYY77IlJFkVYCkWIdRyjjrUkxQdy7tpcy d7gHwlZR7M2Wd1KoFg7yxw==; Received: from 108-223-40-66.lightspeed.sntcca.sbcglobal.net ([108.223.40.66]:47904 helo=server.roeck-us.net) by bh-25.webhostbox.net with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.100.1) (envelope-from ) id 1xLjdj-00000000cHM-1r2U; Tue, 27 Oct 2026 21:33:07 +0530 From: Guenter Roeck To: linux-watchdog@vger.kernel.org Cc: Tzung-Bi Shih , Guenter Roeck Subject: [PATCH v2 3/8] watchdog: core: Prevent ping worker from re-arming timer on suspend Date: Tue, 27 Oct 2026 09:02:57 -0700 Message-ID: <20261027160302.2519282-4-linux@roeck-us.net> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20261027160302.2519282-1-linux@roeck-us.net> References: <20261027160302.2519282-1-linux@roeck-us.net> X-Mailing-List: linux-watchdog@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-BWhitelist: no X-Source-IP: 108.223.40.66 X-Source-L: No X-Exim-ID: 1xLjdj-00000000cHM-1r2U X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 108-223-40-66.lightspeed.sntcca.sbcglobal.net (server.roeck-us.net) [108.223.40.66]:47904 X-Source-Auth: guenter@roeck-us.net X-Email-Count: 8 X-Org: HG=direseller_whb_net_legacy;ORG=directi; X-Source-Cap: cm9lY2s7YWN0aXZzdG07YmgtMjUud2ViaG9zdGJveC5uZXQ= X-Local-Domain: yes X-CMAE-Envelope: MS4xfGm6A70JXffcTSKatFeDoMSqMF0Ln5BFnyP8FmgBTPpYfYFIbIcuIEYXy1SVU0dGOK6+qraglhokzb1vQ4B1ihx4pWeGO2ZkzfczLJEfggzUUPut2Sf+ d1LT0leQUI0e/FSXs1gR6jtnQ9wvnZjiiIyeFuE0sEpj04m74GgZiMmWMUhEGu3xHLvDL1kQ3Jk/zmZ9fW39iw7Z3LMBRlrlEexXt3MQH5naRhW6SGkCrR35 In watchdog_dev_suspend(), hrtimer_cancel() is called before kthread_cancel_work_sync(). If the timer expired just before hrtimer_cancel() and queued watchdog_ping_work(), the worker can run and acquire wd_data->lock while kthread_cancel_work_sync() waits for it to finish. Because no state flag indicates that the watchdog is suspended, watchdog_worker_should_ping() returns true and __watchdog_ping() re-arms wd_data->timer while the device is suspended. Add a _WDOG_SUSPENDED internal status bit to wd_data->status, set it under wd_data->lock in watchdog_dev_suspend(), clear it under wd_data->lock in watchdog_dev_resume(), and check it in watchdog_worker_should_ping(), watchdog_need_worker(), and __watchdog_ping() so the timer cannot be armed while suspended. Fixes: 60bcd91aafd2 ("watchdog: introduce watchdog_dev_suspend/resume") Assisted-by: LLM Reviewed-by: Tzung-Bi Shih Signed-off-by: Guenter Roeck --- v2: Added Reviewed-by: tag drivers/watchdog/watchdog_core.h | 1 + drivers/watchdog/watchdog_dev.c | 15 +++++++++++---- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/watchdog/watchdog_core.h b/drivers/watchdog/watchdog_core.h index ab825d9f9248..c6df5a584357 100644 --- a/drivers/watchdog/watchdog_core.h +++ b/drivers/watchdog/watchdog_core.h @@ -60,6 +60,7 @@ struct watchdog_core_data { #define _WDOG_DEV_OPEN 0 /* Opened ? */ #define _WDOG_ALLOW_RELEASE 1 /* Did we receive the magic char ? */ #define _WDOG_KEEPALIVE 2 /* Did we receive a keepalive ? */ +#define _WDOG_SUSPENDED 3 /* Suspended ? */ }; /* diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index 50224877ff49..e38f1ef8e683 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -81,6 +81,9 @@ static inline bool watchdog_need_worker(struct watchdog_device *wdd) unsigned int hm = wdd->max_hw_heartbeat_ms; unsigned int t = wdd->timeout * 1000; + if (test_bit(_WDOG_SUSPENDED, &wdd->wd_data->status)) + return false; + /* * A worker to generate heartbeat requests is needed if all of the * following conditions are true. @@ -154,9 +157,10 @@ static int __watchdog_ping(struct watchdog_device *wdd) now = ktime_get(); if (ktime_after(earliest_keepalive, now)) { - hrtimer_start(&wd_data->timer, - ktime_sub(earliest_keepalive, now), - HRTIMER_MODE_REL_HARD); + if (!test_bit(_WDOG_SUSPENDED, &wd_data->status)) + hrtimer_start(&wd_data->timer, + ktime_sub(earliest_keepalive, now), + HRTIMER_MODE_REL_HARD); return 0; } @@ -207,7 +211,7 @@ static bool watchdog_worker_should_ping(struct watchdog_core_data *wd_data) { struct watchdog_device *wdd = wd_data->wdd; - if (!wdd) + if (!wdd || test_bit(_WDOG_SUSPENDED, &wd_data->status)) return false; if (watchdog_active(wdd)) @@ -1318,6 +1322,8 @@ int watchdog_dev_suspend(struct watchdog_device *wdd) mutex_lock(&wd_data->lock); if (watchdog_worker_should_ping(wd_data)) ret = __watchdog_ping(wd_data->wdd); + if (!ret) + set_bit(_WDOG_SUSPENDED, &wd_data->status); mutex_unlock(&wd_data->lock); if (ret) @@ -1346,6 +1352,7 @@ int watchdog_dev_resume(struct watchdog_device *wdd) * ping worker if needed. */ mutex_lock(&wd_data->lock); + clear_bit(_WDOG_SUSPENDED, &wd_data->status); if (watchdog_worker_should_ping(wd_data)) ret = __watchdog_ping(wd_data->wdd); mutex_unlock(&wd_data->lock); -- 2.45.2