From nobody Thu Sep 11 22:12:22 2025 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 2BA06C636CC for ; Wed, 15 Feb 2023 13:01:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233425AbjBONBU (ORCPT ); Wed, 15 Feb 2023 08:01:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233917AbjBONBS (ORCPT ); Wed, 15 Feb 2023 08:01:18 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61F7ACA3B for ; Wed, 15 Feb 2023 05:01:17 -0800 (PST) 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 F1CF261B94 for ; 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charset="utf-8" From: Arnd Bergmann When the compiler decides not to inline this function, objtool complains about incorrect UACCESS state: mm/kasan/generic.o: warning: objtool: __asan_load2+0x11: call to addr_has_m= etadata() with UACCESS enabled Acked-by: Peter Zijlstra (Intel) Reviewed-by: Marco Elver Reviewed-by: Andrey Konovalov Signed-off-by: Arnd Bergmann --- v2: fix objdump/objtool typo --- mm/kasan/kasan.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 3231314e071f..9377b0789edc 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -297,7 +297,7 @@ static inline const void *kasan_shadow_to_mem(const voi= d *shadow_addr) << KASAN_SHADOW_SCALE_SHIFT); } =20 -static inline bool addr_has_metadata(const void *addr) +static __always_inline bool addr_has_metadata(const void *addr) { return (kasan_reset_tag(addr) >=3D kasan_shadow_to_mem((void *)KASAN_SHADOW_START)); @@ -316,7 +316,7 @@ bool kasan_check_range(unsigned long addr, size_t size,= bool write, =20 #else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ =20 -static inline bool addr_has_metadata(const void *addr) +static __always_inline bool addr_has_metadata(const void *addr) { return (is_vmalloc_addr(addr) || virt_addr_valid(addr)); } --=20 2.39.1 From nobody Thu Sep 11 22:12:22 2025 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 802E7C636CC for ; Wed, 15 Feb 2023 13:01:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233985AbjBONB3 (ORCPT ); Wed, 15 Feb 2023 08:01:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46148 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233243AbjBONBY (ORCPT ); Wed, 15 Feb 2023 08:01:24 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF4E432E7D for ; Wed, 15 Feb 2023 05:01:22 -0800 (PST) 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 ams.source.kernel.org (Postfix) with ESMTPS id 40593B821C3 for ; Wed, 15 Feb 2023 13:01:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D33BFC4339C; Wed, 15 Feb 2023 13:01:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1676466079; bh=2ZHB4kXmO9QIInQQshGPPjNMQQVO/B7ppuR6Groskjg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Lu0J/SbIWS9+ixPccMmPzBFd9wQGiDgHS5tGpdfzu2X1ttNScPufVWKN4YxkY+2Fd yEvd/lrDUelvVUcKUlWelk6i41CpM+iakWnqD+45tJAakIshZlQoIASn/DShugRUdF LIAYGi8BbC04s3E6k7lyzwqfRsRdZFZ2paJdd6c4ZESmWCoX17BK/JqQwnUGpLEz9e b6yfeo3A3vbGVPmkyqDkRZ6v9UTwjWYjn4t9p9uVQmW1sSiZEzZPXmsGTmsHHdhxaq 2hmIuC3PhRN+4c4XlFCh79d4evkN+67G1XPbt2USq4bhhs0V1sugylow7OFJb9XcSi gi/4JcPUzP61A== From: Arnd Bergmann To: Andrew Morton , Josh Poimboeuf , Peter Zijlstra Cc: Arnd Bergmann , Alexander Potapenko , Andrey Konovalov , Andrey Ryabinin , Dmitry Vyukov , Kuan-Ying Lee , Marco Elver , Vincenzo Frascino , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/3] [v2] kmsan: disable ftrace in kmsan core code Date: Wed, 15 Feb 2023 14:00:57 +0100 Message-Id: <20230215130058.3836177-3-arnd@kernel.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230215130058.3836177-1-arnd@kernel.org> References: <20230215130058.3836177-1-arnd@kernel.org> 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: Arnd Bergmann objtool warns about some suspicous code inside of kmsan: vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_n+0x4: call to __= fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_n+0x4: call to _= _fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_1+0x4: call to __= fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_1+0x4: call to _= _fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_2+0x4: call to __= fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_2+0x4: call to _= _fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_4+0x4: call to __= fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_4+0x4: call to _= _fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_8+0x4: call to __= fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_8+0x4: call to _= _fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_instrument_asm_store+0x4: call to __fen= try__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_chain_origin+0x4: call to __fentry__() = with UACCESS enabled vmlinux.o: warning: objtool: __msan_poison_alloca+0x4: call to __fentry__()= with UACCESS enabled vmlinux.o: warning: objtool: __msan_warning+0x4: call to __fentry__() with = UACCESS enabled vmlinux.o: warning: objtool: __msan_get_context_state+0x4: call to __fentry= __() with UACCESS enabled vmlinux.o: warning: objtool: kmsan_copy_to_user+0x4: call to __fentry__() w= ith UACCESS enabled vmlinux.o: warning: objtool: kmsan_unpoison_memory+0x4: call to __fentry__(= ) with UACCESS enabled vmlinux.o: warning: objtool: kmsan_unpoison_entry_regs+0x4: call to __fentr= y__() with UACCESS enabled vmlinux.o: warning: objtool: kmsan_report+0x4: call to __fentry__() with UA= CCESS enabled The Makefile contained a line to turn off ftrace for the entire directory, but this does not work. Replace it with individual lines, matching the approach in kasan. Fixes: f80be4571b19 ("kmsan: add KMSAN runtime core") Acked-by: Alexander Potapenko Signed-off-by: Arnd Bergmann --- v2: remove the old "CFLAGS_REMOVE.o =3D $(CC_FLAGS_FTRACE)" line --- mm/kmsan/Makefile | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/mm/kmsan/Makefile b/mm/kmsan/Makefile index 98eab2856626..91cfdde642d1 100644 --- a/mm/kmsan/Makefile +++ b/mm/kmsan/Makefile @@ -14,7 +14,13 @@ CC_FLAGS_KMSAN_RUNTIME :=3D -fno-stack-protector CC_FLAGS_KMSAN_RUNTIME +=3D $(call cc-option,-fno-conserve-stack) CC_FLAGS_KMSAN_RUNTIME +=3D -DDISABLE_BRANCH_PROFILING =20 -CFLAGS_REMOVE.o =3D $(CC_FLAGS_FTRACE) +# Disable ftrace to avoid recursion. +CFLAGS_REMOVE_core.o =3D $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_hooks.o =3D $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_init.o =3D $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_instrumentation.o =3D $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_report.o =3D $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_shadow.o =3D $(CC_FLAGS_FTRACE) =20 CFLAGS_core.o :=3D $(CC_FLAGS_KMSAN_RUNTIME) CFLAGS_hooks.o :=3D $(CC_FLAGS_KMSAN_RUNTIME) --=20 2.39.1 From nobody Thu Sep 11 22:12:22 2025 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 BBB85C636CC for ; Wed, 15 Feb 2023 13:01:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234002AbjBONBc (ORCPT ); Wed, 15 Feb 2023 08:01:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46148 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233786AbjBONB1 (ORCPT ); Wed, 15 Feb 2023 08:01:27 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0854431E33 for ; Wed, 15 Feb 2023 05:01:26 -0800 (PST) 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 ams.source.kernel.org (Postfix) with ESMTPS id A7164B821C4 for ; Wed, 15 Feb 2023 13:01:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4813DC433EF; Wed, 15 Feb 2023 13:01:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1676466083; bh=LCrzUXqbVxh67TyCMfdqY6tY7QeA2lgRgFNm/o1Clp0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=trjIqlwZyO+lwC6wY2BwIi2/mShc9WUDm9YrsjZ24D2fsCN/XdBERQW+gmteC8VNN YK4uldLchrzIGLzJ3nz93yG0XY7arZ3i4YgZ2Lc9Mu9lA7KxV1k4dey5CH+NCH8XPe T12gdgRSJvbK/HMFSkuKhQgI07jjONQ6YMov3TAIPRXlQM0Xh0TamEqo1+hkqCwWit A/HGHQ8tTFEqzT5Y7HhQ4ZkU+ePlRphqBw0io5rRVIm9/ye4Ja+OE3AAvycLdCH3OP m22aM8Hqp22iEmk+ci6F6qJRnjS2DdmigNWX2mZU7KKQzMWrXtKyApa/5ozRNmPlry yABFYRztl4azg== From: Arnd Bergmann To: Andrew Morton , Josh Poimboeuf , Peter Zijlstra Cc: Arnd Bergmann , Alexander Potapenko , Andrey Konovalov , Andrey Ryabinin , Dmitry Vyukov , Kuan-Ying Lee , Marco Elver , Vincenzo Frascino , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/3] [v2] objtool: add UACCESS exceptions for __tsan_volatile_read/write Date: Wed, 15 Feb 2023 14:00:58 +0100 Message-Id: <20230215130058.3836177-4-arnd@kernel.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230215130058.3836177-1-arnd@kernel.org> References: <20230215130058.3836177-1-arnd@kernel.org> 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: Arnd Bergmann A lot of the tsan helpers are already excempt from the UACCESS warnings, but some more functions were added that need the same thing: kernel/kcsan/core.o: warning: objtool: __tsan_volatile_read16+0x0: call to = __tsan_unaligned_read16() with UACCESS enabled kernel/kcsan/core.o: warning: objtool: __tsan_volatile_write16+0x0: call to= __tsan_unaligned_write16() with UACCESS enabled vmlinux.o: warning: objtool: __tsan_unaligned_volatile_read16+0x4: call to = __tsan_unaligned_read16() with UACCESS enabled vmlinux.o: warning: objtool: __tsan_unaligned_volatile_write16+0x4: call to= __tsan_unaligned_write16() with UACCESS enabled As Marco points out, these functions don't even call each other explicitly but instead gcc (but not clang) notices the functions being identical and turns one symbol into a direct branch to the other. Fixes: 75d75b7a4d54 ("kcsan: Support distinguishing volatile accesses") Acked-by: Marco Elver Signed-off-by: Arnd Bergmann --- tools/objtool/check.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index b0b467d9608a..da52ce861cc2 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1237,6 +1237,8 @@ static const char *uaccess_safe_builtin[] =3D { "__tsan_atomic64_compare_exchange_val", "__tsan_atomic_thread_fence", "__tsan_atomic_signal_fence", + "__tsan_unaligned_read16", + "__tsan_unaligned_write16", /* KCOV */ "write_comp_data", "check_kcov_mode", --=20 2.39.1