From patchwork Mon Apr 11 15:42:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guenter Roeck X-Patchwork-Id: 12809341 X-Patchwork-Delegate: kvalo@adurom.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8140AC433F5 for ; Mon, 11 Apr 2022 15:42:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348126AbiDKPoj (ORCPT ); Mon, 11 Apr 2022 11:44:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348169AbiDKPog (ORCPT ); Mon, 11 Apr 2022 11:44:36 -0400 Received: from mail-oa1-x32.google.com (mail-oa1-x32.google.com [IPv6:2001:4860:4864:20::32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 004D93B004; Mon, 11 Apr 2022 08:42:19 -0700 (PDT) Received: by mail-oa1-x32.google.com with SMTP id 586e51a60fabf-df22f50e0cso17673359fac.3; Mon, 11 Apr 2022 08:42:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=TxbUHNQvrMBIjTCW3//JKuYPMwW2kqiY97PwifExrW0=; b=XlnjY4oJEsmqZB55ghLmlOimOPY0RzYLb/AfQU6nI2vdlmK0pF0sOosXA5xjhY1xje DcbHccNQE+JUR1/SHK65Pr9104N6ZeutHWlCIR33lxl5VTRZhwsrR1Zv1MY4tnhZvM3z QQKkRGZMeaA20iFJVktLgkSTLRMZmlNG3HobVNASgycrkA0IgK17OZLDMRInivTj85T2 IAs9JRRJet16/+4vjmQN9sb8H0BJSKCLU9c85YUhbi4KJcieBC7WrJNO+PDxolwiBrdM zrUpdvX7r7uUIhpfci5wFFbLklAsC7uUnxbvq82FIH0WsRajKe0xguA7OXJ59PlZy0F4 RA2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; bh=TxbUHNQvrMBIjTCW3//JKuYPMwW2kqiY97PwifExrW0=; b=ypa0TndwiDDhxyZa9Y10ByHStrM7p+ruD9wWU6otFaIiTy7vVwI90SKe4YCt84HyRP 6CD8E0A/SP7YeEF1LmLqC1rY/8WLgr7PCLaXyltfncephDtwyyuOKWqPifKxL/NbKprO 9bDsYYvkw15BoeLNypmuUpGrdu+JuH6/GszZegQYHrrV4HXLyp1Gnuphy+GD1kHsCoGv 8bb8YPfyv4ZheoJ0BWhlb2rj+WrdPj69v0tC938iuq5SWIdIhkypIJUT3Tcle9MwM8+B 9h6k+rS9e+hPyUEBEo9RlXWor6HpwjMy8fIsAzsFIpaxhlDx14nzBHuynYqrl077cKtV IhBw== X-Gm-Message-State: AOAM5338adRH4VI9sVPU/fZMpfQHM92gWPXt0SgvX9vtQBKqIm6zTvaN ajHAvP+o1ja4hns7dd4pTva9sPaJf4g= X-Google-Smtp-Source: ABdhPJzniQoI+xcfeMw2+smpP0QcrSIfAaa6a3E0tMqs8h5Apl4XV+TulHiqRKW4kTxjB+R0UVH00w== X-Received: by 2002:a05:6871:79b:b0:d3:4039:7e7c with SMTP id o27-20020a056871079b00b000d340397e7cmr14657208oap.121.1649691738902; Mon, 11 Apr 2022 08:42:18 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id c9-20020a4a8ec9000000b0032438ba79b0sm11513951ool.0.2022.04.11.08.42.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Apr 2022 08:42:17 -0700 (PDT) Sender: Guenter Roeck From: Guenter Roeck To: linux-wireless@vger.kernel.org Cc: Luca Coelho , Kalle Valo , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Steven Rostedt , Johannes Berg , Guenter Roeck , Gregory Greenman Subject: [PATCH] iwlwifi: iwl-dbg: Use del_timer_sync() before freeing Date: Mon, 11 Apr 2022 08:42:10 -0700 Message-Id: <20220411154210.1870008-1-linux@roeck-us.net> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org In Chrome OS, a large number of crashes is observed due to corrupted timer lists. Steven Rostedt pointed out that this usually happens when a timer is freed while still active, and that the problem is often triggered by code calling del_timer() instead of del_timer_sync() just before freeing. Steven also identified the iwlwifi driver as one of the possible culprits since it does exactly that. Reported-by: Steven Rostedt Cc: Steven Rostedt Cc: Johannes Berg Cc: Gregory Greenman Fixes: 60e8abd9d3e91 ("iwlwifi: dbg_ini: add periodic trigger new API support") Signed-off-by: Guenter Roeck Acked-by: Gregory Greenman Tested-by: Sedat Dilek # Linux v5.17.3-rc1 and --- v1 (from RFC): Removed Shahar S Matityahu from Cc: and added Gregory Greenman. No functional change. I thought about the need to add a mutex to protect the timer list, but I convinced myself that it is not necessary because the code adding the timer list and the code removing it should never be never executed in parallel. drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c index 866a33f49915..3237d4b528b5 100644 --- a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c +++ b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c @@ -371,7 +371,7 @@ void iwl_dbg_tlv_del_timers(struct iwl_trans *trans) struct iwl_dbg_tlv_timer_node *node, *tmp; list_for_each_entry_safe(node, tmp, timer_list, list) { - del_timer(&node->timer); + del_timer_sync(&node->timer); list_del(&node->list); kfree(node); }