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=-6.8 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 autolearn=ham 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 5E8E8C32750 for ; Tue, 13 Aug 2019 18:40:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 382282064A for ; Tue, 13 Aug 2019 18:40:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565721615; bh=SBqAGpMmkteIQgZNhkSh/mHK57XzJcRRIApIV1OWpUs=; h=Subject:To:Cc:From:Date:List-ID:From; b=Mes32tqSpgqlwCHdF62UtISOaKtGO2P792P/Bl0Z5nu4QVZGGjxqwJQJfUHzUY8z9 /rW5jedEVgLKdcPwuZpkPUbAhHKXMs1fZWsSLtSHcO8L0rfDtWFCOC0kpd9dRi4P4B zgC09P1jK94XGkUipL00ZPjBJLkPzRubuSH+RH0k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727042AbfHMSkO (ORCPT ); Tue, 13 Aug 2019 14:40:14 -0400 Received: from wout2-smtp.messagingengine.com ([64.147.123.25]:44365 "EHLO wout2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726427AbfHMSkO (ORCPT ); Tue, 13 Aug 2019 14:40:14 -0400 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.west.internal (Postfix) with ESMTP id 123EC39B; Tue, 13 Aug 2019 14:40:13 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute6.internal (MEProxy); Tue, 13 Aug 2019 14:40:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=Oo2u68 9DHYxBMOXn9qztYpP8zVSu+yngjeXImJavW5o=; b=PXvP7sbuEfGip0z+Bh/OYh YX2DoeXlNT4bIdIVIxO0zvyPaIqFR6kOOITDqaDKTgRiGiYPS5aILqdrytMyTt64 sRHh74WuHxNCRBIH6i9bMWvgjtOISddh2jHKniwGjgpJbn+IwwxB4hh+kBnBFbEH 7uZmyudrg5JiLmFVMN8ThVqUCouaRZuwZSJlv6K6EMQDOypd/2k//zFYDu/66bYD Nq9QYRnks+370heFY3J8QsG4D553AchIqB8S5rSsRwUFwz0wkeUOFtTHa0JZqHMS mADdYBOdRTYwDR2Fz7eR9MVImIBWsSLHe+JLHhhsPTvtsrHKfHbGSJw3GOes0Cdw == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduvddruddviedguddvfecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecunecujfgurhepuffvhfffkfggtgfgsehtkeertd dttdflnecuhfhrohhmpeeoghhrvghgkhhhsehlihhnuhigfhhouhhnuggrthhiohhnrdho rhhgqeenucffohhmrghinhepkhgvrhhnvghlrdhorhhgpdgthhhrohhmihhumhdrohhrgh enucfkphepkeefrdekiedrkeelrddutdejnecurfgrrhgrmhepmhgrihhlfhhrohhmpehg rhgvgheskhhrohgrhhdrtghomhenucevlhhushhtvghrufhiiigvpedu X-ME-Proxy: Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) by mail.messagingengine.com (Postfix) with ESMTPA id F3539380075; Tue, 13 Aug 2019 14:40:11 -0400 (EDT) Subject: FAILED: patch "[PATCH] x86/purgatory: Do not use __builtin_memcpy and" failed to apply to 4.4-stable tree To: ndesaulniers@google.com, adelva@google.com, manojgupta@google.com, tglx@linutronix.de, vaibhavrustagi@google.com Cc: From: Date: Tue, 13 Aug 2019 20:40:09 +0200 Message-ID: <15657216092597@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 4ce97317f41d38584fb93578e922fcd19e535f5b Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Wed, 7 Aug 2019 15:15:32 -0700 Subject: [PATCH] x86/purgatory: Do not use __builtin_memcpy and __builtin_memset Implementing memcpy and memset in terms of __builtin_memcpy and __builtin_memset is problematic. GCC at -O2 will replace calls to the builtins with calls to memcpy and memset (but will generate an inline implementation at -Os). Clang will replace the builtins with these calls regardless of optimization level. $ llvm-objdump -dr arch/x86/purgatory/string.o | tail 0000000000000339 memcpy: 339: 48 b8 00 00 00 00 00 00 00 00 movabsq $0, %rax 000000000000033b: R_X86_64_64 memcpy 343: ff e0 jmpq *%rax 0000000000000345 memset: 345: 48 b8 00 00 00 00 00 00 00 00 movabsq $0, %rax 0000000000000347: R_X86_64_64 memset 34f: ff e0 Such code results in infinite recursion at runtime. This is observed when doing kexec. Instead, reuse an implementation from arch/x86/boot/compressed/string.c. This requires to implement a stub function for warn(). Also, Clang may lower memcmp's that compare against 0 to bcmp's, so add a small definition, too. See also: commit 5f074f3e192f ("lib/string.c: implement a basic bcmp") Fixes: 8fc5b4d4121c ("purgatory: core purgatory functionality") Reported-by: Vaibhav Rustagi Debugged-by: Vaibhav Rustagi Debugged-by: Manoj Gupta Suggested-by: Alistair Delva Signed-off-by: Nick Desaulniers Signed-off-by: Thomas Gleixner Tested-by: Vaibhav Rustagi Cc: stable@vger.kernel.org Link: https://bugs.chromium.org/p/chromium/issues/detail?id=984056 Link: https://lkml.kernel.org/r/20190807221539.94583-1-ndesaulniers@google.com diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c index 401e30ca0a75..8272a4492844 100644 --- a/arch/x86/boot/string.c +++ b/arch/x86/boot/string.c @@ -37,6 +37,14 @@ int memcmp(const void *s1, const void *s2, size_t len) return diff; } +/* + * Clang may lower `memcmp == 0` to `bcmp == 0`. + */ +int bcmp(const void *s1, const void *s2, size_t len) +{ + return memcmp(s1, s2, len); +} + int strcmp(const char *str1, const char *str2) { const unsigned char *s1 = (const unsigned char *)str1; diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index 3cf302b26332..91ef244026d2 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -6,6 +6,9 @@ purgatory-y := purgatory.o stack.o setup-x86_$(BITS).o sha256.o entry64.o string targets += $(purgatory-y) PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y)) +$(obj)/string.o: $(srctree)/arch/x86/boot/compressed/string.c FORCE + $(call if_changed_rule,cc_o_c) + $(obj)/sha256.o: $(srctree)/lib/sha256.c FORCE $(call if_changed_rule,cc_o_c) diff --git a/arch/x86/purgatory/purgatory.c b/arch/x86/purgatory/purgatory.c index 6d8d5a34c377..b607bda786f6 100644 --- a/arch/x86/purgatory/purgatory.c +++ b/arch/x86/purgatory/purgatory.c @@ -68,3 +68,9 @@ void purgatory(void) } copy_backup_region(); } + +/* + * Defined in order to reuse memcpy() and memset() from + * arch/x86/boot/compressed/string.c + */ +void warn(const char *msg) {} diff --git a/arch/x86/purgatory/string.c b/arch/x86/purgatory/string.c deleted file mode 100644 index 01ad43873ad9..000000000000 --- a/arch/x86/purgatory/string.c +++ /dev/null @@ -1,23 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Simple string functions. - * - * Copyright (C) 2014 Red Hat Inc. - * - * Author: - * Vivek Goyal - */ - -#include - -#include "../boot/string.c" - -void *memcpy(void *dst, const void *src, size_t len) -{ - return __builtin_memcpy(dst, src, len); -} - -void *memset(void *dst, int c, size_t len) -{ - return __builtin_memset(dst, c, len); -}