From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 51D87215055; Thu, 24 Jul 2025 05:50:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753336231; cv=none; b=t8+UZP2ynZgHRTZ0lvoc9ko3LFfNAD9lpg1anf/FBirbWqzCUhSc0i9IW7od9g+sBTFnUFbdQDSC17km9xAvm6GEIAhUmF6ZjiGTmRUPPpqajDmB1yQGBg7KR/7DoSFxAEJXsi3WQDfniQ1NsO6uop4/9v1VAjCJDoUI8xbC9nA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753336231; c=relaxed/simple; bh=p+7YUBTmffdnZ8pKAPuZ2rzC3Zvp9P0MFRgY7Xz1ydU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Bfc9RDBQpv63MScwymEV0PIEpL7yQDcIM+6INBWu8ZZnUwR3J6mimoZT22zXSG0HaS/OSMt21hrgsZtxR3HD3+N+eEw9+CtIehgqf/8km/hyeIJzZc1td3J+mkYySKGQZ3/Phlx7UYoMafpcCTa/nN+as88SK5hBBkm7DWyhwQE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QgWgAc1Z; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QgWgAc1Z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B8E6C2BCB2; Thu, 24 Jul 2025 05:50:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753336230; bh=p+7YUBTmffdnZ8pKAPuZ2rzC3Zvp9P0MFRgY7Xz1ydU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QgWgAc1Z4h7uumRs3FFTKmk6zT6WYc3ZB83iSXiAZCG3NFITyJRewAAhvM7SCdTB4 RxT11O3im9HodJy3iQHDCIux7eUlVSNQW6vtNOpk+XKga6Y6fSj/9wwhDqjvs9xFUF rCGWpttB1snOwFhFvWshiFbzZcXiHhUf9pIp6AbINpGCNdRMNio67jDVRMKJBh7BuE fdkdGJldi6mApzEQpFIUP62H0n6GbSbzIk9V1TPCmz4OwMw6YkG/4j38bPS4hFhKJ2 k2xWrnI6HQnV9XChu9iVDC9Tei62bf2nNEwWaweCdPI6/DaXZd3bddGMJWg3LAw2pQ U8NDMsvEgKExw== From: Kees Cook To: Arnd Bergmann Cc: Kees Cook , Masahiro Yamada , Nathan Chancellor , Nicolas Schier , Marco Elver , Andrey Konovalov , Andrey Ryabinin , Ard Biesheuvel , "Gustavo A. R. Silva" , linux-kbuild@vger.kernel.org, kasan-dev@googlegroups.com, linux-hardening@vger.kernel.org, Will Deacon , Catalin Marinas , Jonathan Cameron , Gavin Shan , "Russell King (Oracle)" , James Morse , Oza Pawandeep , Anshuman Khandual , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Paolo Bonzini , Mike Rapoport , Vitaly Kuznetsov , Henrique de Moraes Holschuh , Hans de Goede , =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= , "Rafael J. Wysocki" , Len Brown , Masami Hiramatsu , Michal Wilczynski , Juergen Gross , Andy Shevchenko , "Kirill A. Shutemov" , Roger Pau Monne , David Woodhouse , Usama Arif , "Guilherme G. Piccoli" , Thomas Huth , Brian Gerst , Hou Wenlong , Andrew Morton , "Peter Zijlstra (Intel)" , Luis Chamberlain , Sami Tolvanen , Christophe Leroy , Andy Lutomirski , Baoquan He , Alexander Graf , Changyuan Lyu , Paul Moore , James Morris , "Serge E. Hallyn" , Nick Desaulniers , Bill Wendling , Justin Stitt , Jan Beulich , Boqun Feng , Viresh Kumar , "Paul E. McKenney" , Bibo Mao , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, kvm@vger.kernel.org, ibm-acpi-devel@lists.sourceforge.net, platform-driver-x86@vger.kernel.org, linux-acpi@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-efi@vger.kernel.org, linux-mm@kvack.org, kexec@lists.infradead.org, linux-security-module@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH v4 4/4] kstack_erase: Support Clang stack depth tracking Date: Wed, 23 Jul 2025 22:50:28 -0700 Message-Id: <20250724055029.3623499-4-kees@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250724054419.it.405-kees@kernel.org> References: <20250724054419.it.405-kees@kernel.org> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2299; i=kees@kernel.org; h=from:subject; bh=p+7YUBTmffdnZ8pKAPuZ2rzC3Zvp9P0MFRgY7Xz1ydU=; b=owGbwMvMwCVmps19z/KJym7G02pJDBmNJ5fsPnPUwKQyTLv6YDRX59942Z9pVg4x/Z3tr6sPL i8Lmbqoo5SFQYyLQVZMkSXIzj3OxeNte7j7XEWYOaxMIEMYuDgFYCLbGRj+55xsNLv8fgpvz+zJ 97Q2v1jyfM6aXx5r3h0o/XvrBVfaBhWG/34taus75nNe6jl2+9BH9ihD5yM7dLl817dcaviWpVx +gAsA X-Developer-Key: i=kees@kernel.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: 8bit Wire up CONFIG_KSTACK_ERASE to Clang 21's new stack depth tracking callback[1] option. Link: https://clang.llvm.org/docs/SanitizerCoverage.html#tracing-stack-depth [1] Signed-off-by: Kees Cook --- Cc: Arnd Bergmann Cc: Masahiro Yamada Cc: Nathan Chancellor Cc: Nicolas Schier Cc: Marco Elver Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Ard Biesheuvel Cc: "Gustavo A. R. Silva" Cc: Cc: Cc: --- security/Kconfig.hardening | 5 ++++- scripts/Makefile.kstack_erase | 6 ++++++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening index f7aa2024ab25..b9a5bc3430aa 100644 --- a/security/Kconfig.hardening +++ b/security/Kconfig.hardening @@ -82,10 +82,13 @@ choice endchoice +config CC_HAS_SANCOV_STACK_DEPTH_CALLBACK + def_bool $(cc-option,-fsanitize-coverage-stack-depth-callback-min=1) + config KSTACK_ERASE bool "Poison kernel stack before returning from syscalls" depends on HAVE_ARCH_KSTACK_ERASE - depends on GCC_PLUGINS + depends on GCC_PLUGINS || CC_HAS_SANCOV_STACK_DEPTH_CALLBACK help This option makes the kernel erase the kernel stack before returning from system calls. This has the effect of leaving diff --git a/scripts/Makefile.kstack_erase b/scripts/Makefile.kstack_erase index 5223d3a35817..c7bc2379e113 100644 --- a/scripts/Makefile.kstack_erase +++ b/scripts/Makefile.kstack_erase @@ -8,6 +8,12 @@ kstack-erase-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK_VERBOSE) += -fplugin-arg-stack DISABLE_KSTACK_ERASE := -fplugin-arg-stackleak_plugin-disable endif +ifdef CONFIG_CC_IS_CLANG +kstack-erase-cflags-y += -fsanitize-coverage=stack-depth +kstack-erase-cflags-y += -fsanitize-coverage-stack-depth-callback-min=$(CONFIG_KSTACK_ERASE_TRACK_MIN_SIZE) +DISABLE_KSTACK_ERASE := -fno-sanitize-coverage=stack-depth +endif + KSTACK_ERASE_CFLAGS := $(kstack-erase-cflags-y) export STACKLEAK_CFLAGS DISABLE_KSTACK_ERASE -- 2.34.1