From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1431546-1518324685-2-8115831906599942147 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='uk', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1518324685; b=KYcktGnFMA7BmNkAGIfmtZ6xVnoi4PEScrUzrF+o01XlzEr M7mVv7sKhqmh0f7hyjoT0IiLKr/4RV2jfKwvG0yiLH2HSWjfweMAT5MfFK1De3zU 5a2peM2I7Wvrf0x9z+wU0psZrHH1TM6dBas7Uj2Ziv+AtdijQSssCobFeejPy64h 3ZFF2nn/gA1aILGw2s2dDGnKCTcDNQirpL9rIgaI06lcYjOdsdzEYE6L2mwZXmY8 nbBQIv6FcK5kU9Pr3KVj3I/qSA6GvbBD92c3rWqiTkV/Z/postBZU5zjNUxiX1a0 RG61HLRdW3pLeGX/ETCaEufWMiQDLzOxZUikFKw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:content-transfer-encoding :mime-version:from:to:cc:date:message-id:subject:in-reply-to :sender:list-id; s=arctest; t=1518324685; bh=adsw6eX3hOWYGVc9LA5 2esNdMhzTgESIp+rxlKGApeI=; b=E6UwDowmjOspaMoI0n7eMzwK0HxBv9iNIkj GVRNMxC4ROUFUQaxvtbwMUlrLDfHx9Rlnx21c5A3SxAAXEkZc0c/fozNdAqJkoqO 8Hx/EyXCk6bj83KUcsAFvFOv280yy16mGq6oiYSkSN9FExjsmu3xc+THfn5UTcqK mfpicR2ilQTHPEiHg9DyvAtVTW0eXPtbua7QkB2mEJGThi7m5YwgDEVxkwtFgu9g earm/RQ69PzbBYh7YK2kCysQOyfEjXdnWNxyMabKiKsvNKwISjznhq7VGNRTYYDP uzNH/y/gmZZ18qFJxcexHgi14xs47tpFS9h49Zh2hxck1/d/p1Q== ARC-Authentication-Results: i=1; mx6.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Authentication-Results: mx6.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752830AbeBKEuy (ORCPT ); Sat, 10 Feb 2018 23:50:54 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41781 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752828AbeBKEd6 (ORCPT ); Sat, 10 Feb 2018 23:33:58 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Brian King" , "Jeff Kirsher" , "Jesse Brandeburg" , "Andrew Bowers" Date: Sun, 11 Feb 2018 04:31:11 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 109/136] i40e: Use smp_rmb rather than read_barrier_depends In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 3.16.54-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Brian King commit 52c6912fde0133981ee50ba08808f257829c4c93 upstream. The original issue being fixed in this patch was seen with the ixgbe driver, but the same issue exists with i40e as well, as the code is very similar. read_barrier_depends is not sufficient to ensure loads following it are not speculatively loaded out of order by the CPU, which can result in stale data being loaded, causing potential system crashes. Signed-off-by: Brian King Acked-by: Jesse Brandeburg Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher Signed-off-by: Ben Hutchings --- drivers/net/ethernet/intel/i40e/i40e_main.c | 2 +- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -3047,7 +3047,7 @@ static bool i40e_clean_fdir_tx_irq(struc break; /* prevent any other reads prior to eop_desc */ - read_barrier_depends(); + smp_rmb(); /* if the descriptor isn't done, no work yet to do */ if (!(eop_desc->cmd_type_offset_bsz & --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -657,7 +657,7 @@ static bool i40e_clean_tx_irq(struct i40 break; /* prevent any other reads prior to eop_desc */ - read_barrier_depends(); + smp_rmb(); /* we have caught up to head, no work left to do */ if (tx_head == tx_desc)