From patchwork Fri Feb 21 16:35:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 11396873 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AC13E109A for ; Fri, 21 Feb 2020 16:35:57 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8A67A20722 for ; Fri, 21 Feb 2020 16:35:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="AAAlqkPX" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8A67A20722 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ZrC+3+Aa8w5fJiMyNiABmrl1YMfCyZLcQiR3M7dO840=; b=AAAlqkPXkduo13 A0GYh7r5BW/pJ2Vz55pVC0f0R5agdD0R4CXU2PcVLH/+oVsG3yo2a9to3L7uWBDozcoh5NvfM7RrX SbFfcO+lEJgWnpQvdRGVC9+ofXqP8ciSzegBkq9NpiOMhGzGxdQ0vm1eofLN8DpdoKwJgzqAjsj+h YTrbAuWGwHZUcOzUJXUzEu4rlaqY7VWZ8NDNxV3J/w1Dv9vxZbKFGPQkPoachnl4hWsTh+J6bTZMs r+zBsi59KRcZs6pC9Lcwhc1RtQc1azdfMujSj6+L8ob2xupTq3aBF8gyEqHtdpWq1Hij8A7YtPKXG SXqZ+oUxwJ1kwzEXy9ng==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j5BHP-0000On-Cb; Fri, 21 Feb 2020 16:35:55 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j5BGw-0008P6-5H for linux-arm-kernel@lists.infradead.org; Fri, 21 Feb 2020 16:35:27 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C2183FEC; Fri, 21 Feb 2020 08:35:25 -0800 (PST) Received: from eglon.cambridge.arm.com (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0481C3F68F; Fri, 21 Feb 2020 08:35:24 -0800 (PST) From: James Morse To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 2/4] firmware: arm_sdei: fix possible double-lock on hibernate error path Date: Fri, 21 Feb 2020 16:35:07 +0000 Message-Id: <20200221163509.47254-3-james.morse@arm.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200221163509.47254-1-james.morse@arm.com> References: <20200221163509.47254-1-james.morse@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200221_083526_278262_0A2180EE X-CRM114-Status: GOOD ( 12.82 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [217.140.110.172 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Catalin Marinas , Liguang Zhang , Will Deacon , James Morse Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Liguang Zhang We call sdei_reregister_event() with sdei_list_lock held, if the register fails we call sdei_event_destroy() which also acquires sdei_list_lock thus creating A-A deadlock. Add '_llocked' to sdei_reregister_event(), to indicate the list lock is held, and add a _llocked variant of sdei_event_destroy(). Fixes: da351827240e ("firmware: arm_sdei: Add support for CPU and system power states") Signed-off-by: Liguang Zhang [expanded subject, added wrappers instead of duplicating contents] Signed-off-by: James Morse --- drivers/firmware/arm_sdei.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c index 77eaa9a2fd15..f15f459e9df0 100644 --- a/drivers/firmware/arm_sdei.c +++ b/drivers/firmware/arm_sdei.c @@ -280,13 +280,12 @@ static struct sdei_event *sdei_event_create(u32 event_num, return event; } -static void sdei_event_destroy(struct sdei_event *event) +static void sdei_event_destroy_llocked(struct sdei_event *event) { lockdep_assert_held(&sdei_events_lock); + lockdep_assert_held(&sdei_list_lock); - spin_lock(&sdei_list_lock); list_del(&event->list); - spin_unlock(&sdei_list_lock); if (event->type == SDEI_EVENT_TYPE_SHARED) kfree(event->registered); @@ -296,6 +295,13 @@ static void sdei_event_destroy(struct sdei_event *event) kfree(event); } +static void sdei_event_destroy(struct sdei_event *event) +{ + spin_lock(&sdei_list_lock); + sdei_event_destroy_llocked(event); + spin_unlock(&sdei_list_lock); +} + static int sdei_api_get_version(u64 *version) { return invoke_sdei_fn(SDEI_1_0_FN_SDEI_VERSION, 0, 0, 0, 0, 0, version); @@ -643,16 +649,17 @@ int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg) } EXPORT_SYMBOL(sdei_event_register); -static int sdei_reregister_event(struct sdei_event *event) +static int sdei_reregister_event_llocked(struct sdei_event *event) { int err; lockdep_assert_held(&sdei_events_lock); + lockdep_assert_held(&sdei_list_lock); err = _sdei_event_register(event); if (err) { pr_err("Failed to re-register event %u\n", event->event_num); - sdei_event_destroy(event); + sdei_event_destroy_llocked(event); return err; } @@ -681,7 +688,7 @@ static int sdei_reregister_shared(void) continue; if (event->reregister) { - err = sdei_reregister_event(event); + err = sdei_reregister_event_llocked(event); if (err) break; }