From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-2970050-1519654473-5-10187150807869986961 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, 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='CN', FromHeader='de', 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=1519654473; b=LuQM9MI7RRvNhXCYCqc3GykkJYG2Xjtci9SWP79JY39uehv c0uPEPppbnXfFgj1EgG20D67cZXMfUVpUQ2+FQ7V4hZZI/3tBZPb7DVS193YHACy xV7+pv2zTnaraZ5EVa0/83IJCoxewjm71u9ayrzltoUVLT/f7Yy2Vt6xaMrYULgo MLy2vQlDr84QDoRLWgOBggmKeoQGE2GVrFNGGI4vUkpwiNls5COAhfolaIgNYp7W VnHtgZczxuTPQSI5YS6kN+ZMkJVtcmtLoVkRHYzFc/j4GedH2XMFgK/FiOhGwND3 1gKt/gJsbHLXnJZwOLnzSyOz4Morscfa3QFns9g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=mime-version:in-reply-to:references:from :date:message-id:subject:to:cc:content-type:sender:list-id; s= arctest; t=1519654473; bh=bK3/r1601mTdru1jOUQtcoZMebAchfcjWwrovL rJrzk=; b=hkG1n3qGrfvW//Gc9CjTL5LzkivjnOtHVnq1HxVEm8bOADYcciB099 l8BNPTPw/FmyfM23A4D6MmVdICQ8dRfX0aDx8c22aBsqmKzYkr64KaqWzJjKZcZ6 ceZ8rTh7GP3KARqBHm7ET7ZqqGV722QerQsGYjxz+Jjl2LV87s3mS+MT8px20qW7 +LFAkO4MrZ2l+T1Vu/xgAq9EWrsVSE5BAOdqzCfO1Xpb4Ljr6ArcQqlkMxyXGDwl d9TGBJcIzTsIciEdLTSboH8jgluvnwYl8RBl1mBxLAH7tMDQttS3T1Ok2dTGuLSG JRsAa2pevQNxkXSkCCZoD74E4cJzTkQQ== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=fail (message has been altered; 2048-bit rsa key sha256) header.d=gmail.com header.i=@gmail.com header.b=aXY0nrY8 x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=20161025; dmarc=none (p=none,has-list-id=yes,d=none) header.from=arndb.de; 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-google-dkim=fail (message has been altered; 2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=ZMpITxdh; 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=arndb.de header.result=pass header_is_org_domain=yes Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=fail (message has been altered; 2048-bit rsa key sha256) header.d=gmail.com header.i=@gmail.com header.b=aXY0nrY8 x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=20161025; dmarc=none (p=none,has-list-id=yes,d=none) header.from=arndb.de; 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-google-dkim=fail (message has been altered; 2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=ZMpITxdh; 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=arndb.de header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753298AbeBZOMy (ORCPT ); Mon, 26 Feb 2018 09:12:54 -0500 Received: from mail-qt0-f195.google.com ([209.85.216.195]:46967 "EHLO mail-qt0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753398AbeBZOLD (ORCPT ); Mon, 26 Feb 2018 09:11:03 -0500 X-Google-Smtp-Source: AG47ELujoBl6erBEHclzvumNE+6CLHktmF9kZV8VRVKGYykxjKRYeew3dZNt5WAtyFH9FGV4YFz6U5ELAGE7niSUEIY= MIME-Version: 1.0 In-Reply-To: <20180226032227.14615-3-jerry.hoemann@hpe.com> References: <20180226032227.14615-1-jerry.hoemann@hpe.com> <20180226032227.14615-3-jerry.hoemann@hpe.com> From: Arnd Bergmann Date: Mon, 26 Feb 2018 15:11:01 +0100 X-Google-Sender-Auth: tQbWS-F_QJM5lqPBdMmxSq3bmX0 Message-ID: Subject: Re: [PATCH v5 2/9] watchdog/hpwdt: Remove legacy NMI sourcing. To: Jerry Hoemann Cc: Wim Van Sebroeck , Guenter Roeck , linux-watchdog@vger.kernel.org, Linux Kernel Mailing List , rwright@hpe.com, maurice.a.saldivar@hpe.com, Ingo Molnar , marcus.folkesson@gmail.com, Josh Poimboeuf , stable Content-Type: text/plain; charset="UTF-8" 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: On Mon, Feb 26, 2018 at 4:22 AM, Jerry Hoemann wrote: > Gen8 and prior Proliant systems supported the "CRU" interface > to firmware. This interfaces allows linux to "call back" into firmware > to source the cause of an NMI. This feature isn't fully utilized > as the actual source of the NMI isn't printed, the driver only > indicates that the source couldn't be determined when the call > fails. > > With the advent of Gen9, iCRU replaces the CRU. The call back > feature is no longer available in firmware. To be compatible and > not attempt to call back into firmware on system not supporting CRU, > the SMBIOS table is consulted to determine if it is safe to > make the call back or not. > > This results in about half of the driver code being devoted > to either making CRU calls or determing if it is safe to make > CRU calls. As noted, the driver isn't really using the results of > the CRU calls. > > Furthermore, as a consequence of the Spectre security issue, the > BIOS/EFI calls are being wrapped into Spectre-disabling section. > Removing the call back in hpwdt_pretimeout assists in this effort. > > As the CRU sourcing of the NMI isn't required for handling the > NMI and there are security concerns with making the call back, remove > the legacy (pre Gen9) NMI sourcing and the DMI code to determine if > the system had the CRU interface. > > Signed-off-by: Jerry Hoemann This avoids a warning in mainline kernels, so that's great: drivers/watchdog/hpwdt.o: warning: objtool: .text+0x24: indirect call found in RETPOLINE build I wonder what we do about stable kernels. Are both this patch and the patch that added the objtool warning message candidates for backports to stable kernels? Arnd