From patchwork Fri Sep 17 14:59:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 12502359 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=-17.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 B511DC433EF for ; Fri, 17 Sep 2021 15:02:27 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7D40B61164 for ; Fri, 17 Sep 2021 15:02:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 7D40B61164 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=fLd70SlxN39kuAuU4BqSyhMOVA9g9IuiEIROw0Du/ug=; b=nA8pOtu2K9uDxL Dv91ZDYjQFUYuVWqwHOhDFYDMuOb9S7H9EV/CwTujdDrDx+xH3Zeyii7T4sVgKMecTOFg4Eo2GU9D 8gpsZGrcPKjuzdZeZSupWvAZ3WwY5JhPOWHAtcliV0P0ebLud72mQ1wHxK8DudHJdLNwBdzefCcnw 9Ff/f+FCEwKI25YeYfAUvVixV+LmSUHO//jrjlI9SZbfqTMW1LVymk2mVB5rTob8m7UZGJZ3Hd6qb wkwPp7ozwdOy63+6xn4QGETs+2evLNfMQCbF2YAGnCbc+yM+6gkG0GUnFUwTIaRndUmftR5UcpnOb VxVAyXmE0ztR7FdoQUcw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mRFL8-00ETdO-HL; Fri, 17 Sep 2021 14:59:46 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mRFL5-00ETbi-DY for linux-arm-kernel@lists.infradead.org; Fri, 17 Sep 2021 14:59:44 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0F885101E; Fri, 17 Sep 2021 07:59:37 -0700 (PDT) Received: from e110467-lin.cambridge.arm.com (e110467-lin.cambridge.arm.com [10.1.196.41]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 43D643F59C; Fri, 17 Sep 2021 07:59:36 -0700 (PDT) From: Robin Murphy To: will@kernel.org, catalin.marinas@arm.com Cc: linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com, Branislav Rankov Subject: [PATCH] arm64: Mitigate MTE issues with str{n}cmp() Date: Fri, 17 Sep 2021 15:59:30 +0100 Message-Id: <34dc4d12eec0adae49b0ac927df642ed10089d40.1631890770.git.robin.murphy@arm.com> X-Mailer: git-send-email 2.21.0.dirty MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210917_075943_589394_270A16B5 X-CRM114-Status: GOOD ( 10.68 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org As with strlen(), the patches importing the updated str{n}cmp() implementations were originally developed and tested before the advent of CONFIG_KASAN_HW_TAGS, and have subsequently revealed not to be MTE-safe. Since in-kernel MTE is still a rather niche case, let it temporarily fall back to the generic C versions for correctness until we can figure out the best fix. Reported-by: Branislav Rankov Signed-off-by: Robin Murphy Acked-by: Mark Rutland --- arch/arm64/include/asm/assembler.h | 5 +++++ arch/arm64/include/asm/string.h | 2 ++ arch/arm64/lib/strcmp.S | 2 +- arch/arm64/lib/strncmp.S | 2 +- 4 files changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index 89faca0e740d..bfa58409a4d4 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -525,6 +525,11 @@ alternative_endif #define EXPORT_SYMBOL_NOKASAN(name) EXPORT_SYMBOL(name) #endif +#ifdef CONFIG_KASAN_HW_TAGS +#define EXPORT_SYMBOL_NOHWKASAN(name) +#else +#define EXPORT_SYMBOL_NOHWKASAN(name) EXPORT_SYMBOL_NOKASAN(name) +#endif /* * Emit a 64-bit absolute little endian symbol reference in a way that * ensures that it will be resolved at build time, even when building a diff --git a/arch/arm64/include/asm/string.h b/arch/arm64/include/asm/string.h index 3a3264ff47b9..95f7686b728d 100644 --- a/arch/arm64/include/asm/string.h +++ b/arch/arm64/include/asm/string.h @@ -12,11 +12,13 @@ extern char *strrchr(const char *, int c); #define __HAVE_ARCH_STRCHR extern char *strchr(const char *, int c); +#ifndef CONFIG_KASAN_HW_TAGS #define __HAVE_ARCH_STRCMP extern int strcmp(const char *, const char *); #define __HAVE_ARCH_STRNCMP extern int strncmp(const char *, const char *, __kernel_size_t); +#endif #define __HAVE_ARCH_STRLEN extern __kernel_size_t strlen(const char *); diff --git a/arch/arm64/lib/strcmp.S b/arch/arm64/lib/strcmp.S index d7bee210a798..83bcad72ec97 100644 --- a/arch/arm64/lib/strcmp.S +++ b/arch/arm64/lib/strcmp.S @@ -173,4 +173,4 @@ L(done): ret SYM_FUNC_END_PI(strcmp) -EXPORT_SYMBOL_NOKASAN(strcmp) +EXPORT_SYMBOL_NOHWKASAN(strcmp) diff --git a/arch/arm64/lib/strncmp.S b/arch/arm64/lib/strncmp.S index 48d44f7fddb1..e42bcfcd37e6 100644 --- a/arch/arm64/lib/strncmp.S +++ b/arch/arm64/lib/strncmp.S @@ -258,4 +258,4 @@ L(ret0): ret SYM_FUNC_END_PI(strncmp) -EXPORT_SYMBOL_NOKASAN(strncmp) +EXPORT_SYMBOL_NOHWKASAN(strncmp)