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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 78BE0C7618F for ; Wed, 24 Jul 2019 20:05:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C35E205C9 for ; Wed, 24 Jul 2019 20:05:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563998725; bh=Ex8sdjT459ZaGTa7Tf/mq4wHaSFlpZiJDjcTXb9NDJI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sjKWvjN5fvat39EZnAFv/8UrjpDvk6xtLVRlIbbjuYlDqrYdVzeWLcm182LM9ORvT +pLOgHx7vUNhHoQRPcxkhlOhGnSpnabauMG5EHEG3/KMUYvVrT0nGBG2WmkY29zBc6 v7fztZAUqoMFsjjVWnYhOai/G3TtB8ufpDWgoPNs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405706AbfGXUDX (ORCPT ); Wed, 24 Jul 2019 16:03:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:53742 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405699AbfGXUDX (ORCPT ); Wed, 24 Jul 2019 16:03:23 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C47FA214AF; Wed, 24 Jul 2019 20:03:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563998602; bh=Ex8sdjT459ZaGTa7Tf/mq4wHaSFlpZiJDjcTXb9NDJI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a+/0ZhfhalFvFJB0Op35ad+ZqadvSTnJj/OIDfB9y6s9JK+YV1Hew4Z/1gfR+DE0Y godQN3EVW7wn9RlYL/PZmnPF5Wktmt/ZvRtsqrD7Oq0yr7dU9ucdX1YK+DmMy1eAqo OA80E+aPbbL1LX6It+aT4L24Y7NSwbh03bG/Ca88= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Borislav Petkov , Tony Luck , linux-edac , Sasha Levin Subject: [PATCH 4.19 051/271] RAS/CEC: Fix pfn insertion Date: Wed, 24 Jul 2019 21:18:40 +0200 Message-Id: <20190724191659.526723066@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190724191655.268628197@linuxfoundation.org> References: <20190724191655.268628197@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ 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