From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7010DC3F2CD for ; Tue, 3 Mar 2020 02:42:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 319122465E for ; Tue, 3 Mar 2020 02:42:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fR50jNav" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727018AbgCCCgz (ORCPT ); Mon, 2 Mar 2020 21:36:55 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:36829 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726942AbgCCCgy (ORCPT ); Mon, 2 Mar 2020 21:36:54 -0500 Received: by mail-pf1-f195.google.com with SMTP id i13so681154pfe.3 for ; Mon, 02 Mar 2020 18:36:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=RMQ9gygXU0j/rnN/vo74F76HOdw/OIND39QkStwRaA8=; b=fR50jNav/kAWk1v0287lRUj1jc1aa0QdrgtIPfyt87jXJNcjxBEmxtKKul9aVO4P0V dXa6SP3xeCChmFyptwM8yhWl8o1PBgXnKPBfEAVfcEqyhltOL+ulZsZyWFx/TxV1i/aZ o0q46MY/Gh0w60pQcPMcRlCufqOdjz8Og5ph1CA7OXkU2AogDgyzaK+MUJNmaoDLzwFx lyxsWeNg2+LNOadMoz3gOHwTeW60AxgPHw0iLnyz8IXusJcSRIuQCpSp2ABTDNqOtJSe qZ2oQVr1bZaG0b500IxSkfLF7nl0QLpONckq/yM19biE5CMwlPqJgWYsXyuaPYuLbss2 L2FQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=RMQ9gygXU0j/rnN/vo74F76HOdw/OIND39QkStwRaA8=; b=BAqCaYpKZJUApQCUNiOc4WPbj6FVl5PsYzHNHlx6x3DmMrlBbsMq9MSxX6J6PpKDTT R4x4PeJMIa6c48L6EIUNs0xL9NPVSLgOSITe76rQpP3oTAN/OZLPnzYiZHlDZu1qyEi6 kaPaDniN+k1PYes3wLegVEN24/7yH1qX2cx0SG34XuqXAsR+uBovYa7UMz3gbPysBGu3 6UiCQlgkng635s9Erb+8HABG7gwOQWtg7ff11dEyXwkJzSJPQcEFb+LuHvwq7XogZXqq BnZKzatwXwlcvNJZ6BjbfPik4VItGF+I8J27mJF77iKO/YUQVWi5JVHp7k+bOyOxM9UW zR7w== X-Gm-Message-State: ANhLgQ2+TIjwAPU/DHPXb95YEdr123DMjwbLj1tU3QALP8y6K1P+5n3O 3JExl0jXXeHspKuXnnNuNLvlXvt1N68= X-Google-Smtp-Source: ADFU+vt0FkANtpknOcwjsq6RStbK5ZqMwLKwMhbFQQ2R+JU6veW/0N4bsHoa5vdOKnbdv6RUc9/u4Q== X-Received: by 2002:a63:f74a:: with SMTP id f10mr1900596pgk.360.1583203013723; Mon, 02 Mar 2020 18:36:53 -0800 (PST) Received: from localhost ([43.224.245.180]) by smtp.gmail.com with ESMTPSA id q66sm23317925pfq.27.2020.03.02.18.36.52 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 02 Mar 2020 18:36:53 -0800 (PST) From: Junyong Sun X-Google-Original-From: Junyong Sun To: mcgrof@kernel.org Cc: gregkh@linuxfoundation.org, rafael@kernel.org, linux-kernel@vger.kernel.org, sunjunyong@xiaomi.com Subject: [PATCH v2] firmware: fix a double abort case with fw_load_sysfs_fallback Date: Tue, 3 Mar 2020 10:36:08 +0800 Message-Id: <1583202968-28792-1-git-send-email-sunjunyong@xiaomi.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org fw_sysfs_wait_timeout may return err with -ENOENT at fw_load_sysfs_fallback and firmware is already in abort status, no need to abort again, so skip it. This issue is caused by concurrent situation like below: when thread 1# wait firmware loading, thread 2# may write -1 to abort loading and wakeup thread 1# before it timeout. so wait_for_completion_killable_timeout of thread 1# would return remaining time which is != 0 with fw_st->status FW_STATUS_ABORTED.And the results would be converted into err -ENOENT in __fw_state_wait_common and transfered to fw_load_sysfs_fallback in thread 1#. The -ENOENT means firmware status is already at ABORTED, so fw_load_sysfs_fallback no need to get mutex to abort again. ----------------------------- thread 1#,wait for loading fw_load_sysfs_fallback ->fw_sysfs_wait_timeout ->__fw_state_wait_common ->wait_for_completion_killable_timeout in __fw_state_wait_common, ... 93 ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout); 94 if (ret != 0 && fw_st->status == FW_STATUS_ABORTED) 95 return -ENOENT; 96 if (!ret) 97 return -ETIMEDOUT; 98 99 return ret < 0 ? ret : 0; ----------------------------- thread 2#, write -1 to abort loading firmware_loading_store ->fw_load_abort ->__fw_load_abort ->fw_state_aborted ->__fw_state_set ->complete_all in __fw_state_set, ... 111 if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED) 112 complete_all(&fw_st->completion); ------------------------------------------- BTW,the double abort issue would not cause kernel panic or create an issue, but slow down it sometimes.The change is just a minor optimization. Signed-off-by: Junyong Sun --- changes in v2: - modify the commit log of patch --- drivers/base/firmware_loader/fallback.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c index 8704e1b..1e9c96e 100644 --- a/drivers/base/firmware_loader/fallback.c +++ b/drivers/base/firmware_loader/fallback.c @@ -525,7 +525,7 @@ static int fw_load_sysfs_fallback(struct fw_sysfs *fw_sysfs, } retval = fw_sysfs_wait_timeout(fw_priv, timeout); - if (retval < 0) { + if (retval < 0 && retval != -ENOENT) { mutex_lock(&fw_lock); fw_load_abort(fw_sysfs); mutex_unlock(&fw_lock); -- 2.7.4