From nobody Tue Apr 7 23:59:42 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB4D9C4332F for ; Wed, 19 Oct 2022 23:05:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231206AbiJSXFI (ORCPT ); Wed, 19 Oct 2022 19:05:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231655AbiJSXEw (ORCPT ); Wed, 19 Oct 2022 19:04:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4DE57564EF; Wed, 19 Oct 2022 16:04:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 23C19619D2; Wed, 19 Oct 2022 23:04:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73A26C433B5; Wed, 19 Oct 2022 23:04:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666220647; bh=qrqPKPwr1n/2IdbOQDBDR4+6FyQRRkoFtnq68ywy8ig=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EdE+Cx/4/hLRjEaXZ4WxQi5eT/mrFUyrIENO/UigZGDLm0MgnRcTIOd5ml7YaE2Dq I3vknSnG5noNinnmmb/tR2gFRms2QUozt+fY2SY4oCRYexkMDKW4wRK1toXH1xIRlB hoPE5RlnjDps7GnXfZfSO21Up7+GRdJ1GKFQ9G0unLVxC8yJw4W6xpiD6bwi2rrPg2 qcIVSXI75u6dK5fouvr8BA+soS+PQEfttdfge00t3dPpdECT54ArZKPFbhuymwlH/4 wEByOMtCbmb+IHRrINkuPGlG5OPT0aXUirZbTNw40E62wJB0nY7NY4PElL7QgJRBVD d/aQ+TLq2C+oA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 2A0DF5C06B4; Wed, 19 Oct 2022 16:04:07 -0700 (PDT) From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, kernel-team@fb.com, mingo@kernel.org Cc: elver@google.com, andreyknvl@google.com, glider@google.com, dvyukov@google.com, cai@lca.pw, boqun.feng@gmail.com, stable@vger.kernel.org, "Paul E . McKenney" Subject: [PATCH kcsan 1/3] kcsan: Instrument memcpy/memset/memmove with newer Clang Date: Wed, 19 Oct 2022 16:04:03 -0700 Message-Id: <20221019230405.2502089-1-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20221019230356.GA2501950@paulmck-ThinkPad-P17-Gen-1> References: <20221019230356.GA2501950@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Marco Elver With Clang version 16+, -fsanitize=3Dthread will turn memcpy/memset/memmove calls in instrumented functions into __tsan_memcpy/__tsan_memset/__tsan_memmove calls respectively. Add these functions to the core KCSAN runtime, so that we (a) catch data races with mem* functions, and (b) won't run into linker errors with such newer compilers. Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Marco Elver Signed-off-by: Paul E. McKenney --- kernel/kcsan/core.c | 50 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c index fe12dfe254ecf..54d077e1a2dc7 100644 --- a/kernel/kcsan/core.c +++ b/kernel/kcsan/core.c @@ -14,10 +14,12 @@ #include #include #include +#include #include #include #include #include +#include #include =20 #include "encoding.h" @@ -1308,3 +1310,51 @@ noinline void __tsan_atomic_signal_fence(int memorde= r) } } EXPORT_SYMBOL(__tsan_atomic_signal_fence); + +#ifdef __HAVE_ARCH_MEMSET +void *__tsan_memset(void *s, int c, size_t count); +noinline void *__tsan_memset(void *s, int c, size_t count) +{ + /* + * Instead of not setting up watchpoints where accessed size is greater + * than MAX_ENCODABLE_SIZE, truncate checked size to MAX_ENCODABLE_SIZE. + */ + size_t check_len =3D min_t(size_t, count, MAX_ENCODABLE_SIZE); + + check_access(s, check_len, KCSAN_ACCESS_WRITE, _RET_IP_); + return memset(s, c, count); +} +#else +void *__tsan_memset(void *s, int c, size_t count) __alias(memset); +#endif +EXPORT_SYMBOL(__tsan_memset); + +#ifdef __HAVE_ARCH_MEMMOVE +void *__tsan_memmove(void *dst, const void *src, size_t len); +noinline void *__tsan_memmove(void *dst, const void *src, size_t len) +{ + size_t check_len =3D min_t(size_t, len, MAX_ENCODABLE_SIZE); + + check_access(dst, check_len, KCSAN_ACCESS_WRITE, _RET_IP_); + check_access(src, check_len, 0, _RET_IP_); + return memmove(dst, src, len); +} +#else +void *__tsan_memmove(void *dst, const void *src, size_t len) __alias(memmo= ve); +#endif +EXPORT_SYMBOL(__tsan_memmove); + +#ifdef __HAVE_ARCH_MEMCPY +void *__tsan_memcpy(void *dst, const void *src, size_t len); +noinline void *__tsan_memcpy(void *dst, const void *src, size_t len) +{ + size_t check_len =3D min_t(size_t, len, MAX_ENCODABLE_SIZE); + + check_access(dst, check_len, KCSAN_ACCESS_WRITE, _RET_IP_); + check_access(src, check_len, 0, _RET_IP_); + return memcpy(dst, src, len); +} +#else +void *__tsan_memcpy(void *dst, const void *src, size_t len) __alias(memcpy= ); +#endif +EXPORT_SYMBOL(__tsan_memcpy); --=20 2.31.1.189.g2e36527f23