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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 1CF2BC76195 for ; Mon, 15 Jul 2019 14:57:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E7E19205ED for ; Mon, 15 Jul 2019 14:57:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563202648; bh=oPD6bOUlXEdTcnSJVgy5DPQWInMIKIvhk3WyIgRbzfs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Fam2K2WIjVHFh7Vx2SxZ2dQPU7LOW8wBZlcSuhgkf4h5Y6AfFT5xv5rL2qrrWKf0Q MQ9hLkPiZxjMnYPUDFjRg3uZ3ElZcqkbgPEZmO02V9Ed/2k4+o+n40O2GuvQH7LjWl hF9P6A6z3+uJpn8fABcU6B2KsmKWjb30RLciGSPQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390251AbfGOOUg (ORCPT ); Mon, 15 Jul 2019 10:20:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:45246 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390270AbfGOOUf (ORCPT ); Mon, 15 Jul 2019 10:20:35 -0400 Received: from sasha-vm.mshome.net (unknown [73.61.17.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 80EB6206B8; Mon, 15 Jul 2019 14:20:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563200434; bh=oPD6bOUlXEdTcnSJVgy5DPQWInMIKIvhk3WyIgRbzfs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a4d834uNMEexN0EPLNlV+D2e9PPp/LcJwGvzVhZR9lNiiBSoClHSnvy9x3kpzV2VG rbmOvJT1P4kWroe9TWG8AIxnSOOTNLybXhWWh8KCnOjBIOsf3AdQ6ivBsuTzr7Ipbg hpHZxJWY8DBSn0tKq9u09sV0YJ8rEiIZh8pNBYaQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Borislav Petkov , Tony Luck , linux-edac , Sasha Levin Subject: [PATCH AUTOSEL 4.19 049/158] RAS/CEC: Fix pfn insertion Date: Mon, 15 Jul 2019 10:16:20 -0400 Message-Id: <20190715141809.8445-49-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190715141809.8445-1-sashal@kernel.org> References: <20190715141809.8445-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Borislav Petkov [ Upstream commit 6d8e294bf5f0e85c34e8b14b064e2965f53f38b0 ] When inserting random PFNs for debugging the CEC through (debugfs)/ras/cec/pfn, depending on the return value of pfn_set(), multiple values get inserted per a single write. That is because simple_attr_write() interprets a retval of 0 as success and claims the whole input. However, pfn_set() returns the cec_add_elem() value, which, if > 0 and smaller than the whole input length, makes glibc continue issuing the write syscall until there's input left: pfn_set simple_attr_write debugfs_attr_write full_proxy_write vfs_write ksys_write do_syscall_64 entry_SYSCALL_64_after_hwframe leading to those repeated calls. Return 0 to fix that. Signed-off-by: Borislav Petkov Cc: Tony Luck Cc: linux-edac Signed-off-by: Sasha Levin --- drivers/ras/cec.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c index f85d6b7a1984..5d2b2c02cbbe 100644 --- a/drivers/ras/cec.c +++ b/drivers/ras/cec.c @@ -369,7 +369,9 @@ static int pfn_set(void *data, u64 val) { *(u64 *)data = val; - return cec_add_elem(val); + cec_add_elem(val); + + return 0; } DEFINE_DEBUGFS_ATTRIBUTE(pfn_ops, u64_get, pfn_set, "0x%llx\n"); -- 2.20.1