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 89F62226540; Thu, 12 Dec 2024 16:22:37 +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=1734020557; cv=none; b=KKae+7WiaDe0Ry32ZWFZbWDEDoh5vwiMwNtqjFy9C5ePx8245bzeHuYCVt3QZ7M+hMAdqaUJZe92bz4d4XUWp6BZvPNPvF56rQXtscJZfmobrZ8GZSrcVBwnLnEyoOsMn7qPvitiH5laeY6pJc869omu+wQganDVe1NCXMUy3fw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734020557; c=relaxed/simple; bh=nmfyu8jEt+m3f0HDFMvTVA6G6ZmSfPuAP51XwSCj6cw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tkmPEVEv89DUI1BSUQ+QQ6ns6T6vGORH2wDNK5mkBWYbI9x6R1Qi5LMGJhFtZ+i/2aM41mUX21KZIFm5IVRWoSy9coeZRe58ErvesIVYXn+4B3VfL109m4lPAaO41dsrvAHSfqqBbnfBWqHzhTV4GQ264NYVLby3gKzNOv9Wx9Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=L8AAnJrG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="L8AAnJrG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 09BA6C4CECE; Thu, 12 Dec 2024 16:22:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1734020557; bh=nmfyu8jEt+m3f0HDFMvTVA6G6ZmSfPuAP51XwSCj6cw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L8AAnJrGO8hPC88u93bzJ5MbNTBtBxI7KQV66K+LboSad7uVenm5D+6SDbxrRcwZo gWFFBLscZG8FVLL6hZIUwN9p8bnqr+mEDm3SeRMe9kBp49y3HIj2iyMn3QyivCah5s j5GJyAp/UIjmH2puPLVRc4ErA4P/KdqB+GSa/bXs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Keith Packard , Nathan Chancellor , Michael Ellerman Subject: [PATCH 6.1 499/772] powerpc: Fix stack protector Kconfig test for clang Date: Thu, 12 Dec 2024 15:57:24 +0100 Message-ID: <20241212144410.581807002@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241212144349.797589255@linuxfoundation.org> References: <20241212144349.797589255@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nathan Chancellor commit 46e1879deea22eed31e9425d58635895fc0e8040 upstream. Clang's in-progress per-task stack protector support [1] does not work with the current Kconfig checks because '-mstack-protector-guard-offset' is not provided, unlike all other architecture Kconfig checks. $ fd Kconfig -x rg -l mstack-protector-guard-offset ./arch/arm/Kconfig ./arch/riscv/Kconfig ./arch/arm64/Kconfig This produces an error from clang, which is interpreted as the flags not being supported at all when they really are. $ clang --target=powerpc64-linux-gnu \ -mstack-protector-guard=tls \ -mstack-protector-guard-reg=r13 \ -c -o /dev/null -x c /dev/null clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default This argument will always be provided by the build system, so mirror other architectures and use '-mstack-protector-guard-offset=0' for testing support, which fixes the issue for clang and does not regress support with GCC. Even with the first problem addressed, the 32-bit test continues to fail because Kbuild uses the powerpc64le-linux-gnu target for clang and nothing flips the target to 32-bit, resulting in an error about an invalid register valid: $ clang --target=powerpc64le-linux-gnu \ -mstack-protector-guard=tls -mstack-protector-guard-reg=r2 \ -mstack-protector-guard-offset=0 \ -x c -c -o /dev/null /dev/null clang: error: invalid value 'r2' in 'mstack-protector-guard-reg=', expected one of: r13 While GCC allows arbitrary registers, the implementation of '-mstack-protector-guard=tls' in LLVM shares the same code path as the user space thread local storage implementation, which uses a fixed register (2 for 32-bit and 13 for 62-bit), so the command line parsing enforces this limitation. Use the Kconfig macro '$(m32-flag)', which expands to '-m32' when supported, in the stack protector support cc-option call to properly switch the target to a 32-bit one, which matches what happens in Kbuild. While the 64-bit macro does not strictly need it, add the equivalent 64-bit option for symmetry. Cc: stable@vger.kernel.org # 6.1+ Link: https://github.com/llvm/llvm-project/pull/110928 [1] Reviewed-by: Keith Packard Tested-by: Keith Packard Signed-off-by: Nathan Chancellor Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20241009-powerpc-fix-stackprotector-test-clang-v2-1-12fb86b31857@kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -253,8 +253,8 @@ config PPC select HAVE_RSEQ select HAVE_SETUP_PER_CPU_AREA if PPC64 select HAVE_SOFTIRQ_ON_OWN_STACK - select HAVE_STACKPROTECTOR if PPC32 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r2) - select HAVE_STACKPROTECTOR if PPC64 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r13) + select HAVE_STACKPROTECTOR if PPC32 && $(cc-option,$(m32-flag) -mstack-protector-guard=tls -mstack-protector-guard-reg=r2 -mstack-protector-guard-offset=0) + select HAVE_STACKPROTECTOR if PPC64 && $(cc-option,$(m64-flag) -mstack-protector-guard=tls -mstack-protector-guard-reg=r13 -mstack-protector-guard-offset=0) select HAVE_STATIC_CALL if PPC32 select HAVE_SYSCALL_TRACEPOINTS select HAVE_VIRT_CPU_ACCOUNTING