From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 612E12FB2 for ; Wed, 22 Sep 2021 20:55:39 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id DB41261353; Wed, 22 Sep 2021 20:55:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632344138; bh=M7iLfrDWnvEHZ35K9OsYIwOfFvN+NiWTqgmxlmOCDLY=; h=From:To:Cc:Subject:Date:From; b=JoazlHT/9BFamaVgzKt87cguKza0c1DpbyMR5xYlqaSOs+SWdPDq//TJUOnqg8U3l uR0mXKOrrn61NkOm2qMfwpGQ1698WlmeM2Zt9xzl5wyNFa47OQUgVQTWFtzTdV8zt5 FE6fWGRRGNDpRCKUVRDPe1vRuA0KidDMfp5NEgUmgOxhA73vDtDl9bFo+t8wy2Rrzo YM+d2jFBt+yV1n8e9eaMjGXMBC+1xwjyiiptVXGYRO/6bV6B59C/mkT4djBKMj3Oib HeB7SLC/yIXx2jFkp6bJ6NyLznb6lFl2WTHVOQe57lZEpCohrROhS5Ow0ZM8mqNY0w cX7dZPPDpeq5Q== From: Nathan Chancellor To: Andrey Ryabinin Cc: Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Nick Desaulniers , Arnd Bergmann , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, Nathan Chancellor Subject: [PATCH] kasan: Always respect CONFIG_KASAN_STACK Date: Wed, 22 Sep 2021 13:55:25 -0700 Message-Id: <20210922205525.570068-1-nathan@kernel.org> X-Mailer: git-send-email 2.33.0.514.g99c99ed825 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Bot: notify Content-Transfer-Encoding: 8bit Currently, the asan-stack parameter is only passed along if CFLAGS_KASAN_SHADOW is not empty, which requires KASAN_SHADOW_OFFSET to be defined in Kconfig so that the value can be checked. In RISC-V's case, KASAN_SHADOW_OFFSET is not defined in Kconfig, which means that asan-stack does not get disabled with clang even when CONFIG_KASAN_STACK is disabled, resulting in large stack warnings with allmodconfig: drivers/video/fbdev/omap2/omapfb/displays/panel-lgphilips-lb035q02.c:117:12: error: stack frame size (14400) exceeds limit (2048) in function 'lb035q02_connect' [-Werror,-Wframe-larger-than] static int lb035q02_connect(struct omap_dss_device *dssdev) ^ 1 error generated. Ensure that the value of CONFIG_KASAN_STACK is always passed along to the compiler so that these warnings do not happen when CONFIG_KASAN_STACK is disabled. Link: https://github.com/ClangBuiltLinux/linux/issues/1453 References: 6baec880d7a5 ("kasan: turn off asan-stack for clang-8 and earlier") Signed-off-by: Nathan Chancellor --- scripts/Makefile.kasan | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan index 801c415bac59..b9e94c5e7097 100644 --- a/scripts/Makefile.kasan +++ b/scripts/Makefile.kasan @@ -33,10 +33,11 @@ else CFLAGS_KASAN := $(CFLAGS_KASAN_SHADOW) \ $(call cc-param,asan-globals=1) \ $(call cc-param,asan-instrumentation-with-call-threshold=$(call_threshold)) \ - $(call cc-param,asan-stack=$(stack_enable)) \ $(call cc-param,asan-instrument-allocas=1) endif +CFLAGS_KASAN += $(call cc-param,asan-stack=$(stack_enable)) + endif # CONFIG_KASAN_GENERIC ifdef CONFIG_KASAN_SW_TAGS base-commit: 4057525736b159bd456732d11270af2cc49ec21f -- 2.33.0.514.g99c99ed825