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 C16EC1465AB; Fri, 6 Dec 2024 15:26:12 +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=1733498772; cv=none; b=eODXUicLUMgFtn064+672LOqswAhmB34zxweblynzGt2eKByplfemdGUlXcjjtQ4ghKIpz+UDfOSCL/0Lr6k/Ojy4Pi0JNoc8kuV4a5eCtcfPOBdKhmKtxCppaVQJGGpkcjFSJye4DmyLu60k0P5z3vS65hM2ssn9/cJU66A4hM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733498772; c=relaxed/simple; bh=le7T2cfpLPHooxLTetQGbN+niTjmoardsw8qa5wNwZM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jSazmtGzdvOxaGyuQ+P3M06YwkTY5TkHVyoENRbS71kDkmechWRX143VWD6TE0Ksf5d7R4X6Hy0P79xJgA0ZcgJAt+K+GuELWCVbj4VCeuhWqxIYDizrhcEYsdz4Rw1AktnkpnPxg7ASJ2uPSC4WY2s69zJJzZBz97GVqHlXi6g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=w74k3owv; 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="w74k3owv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 85D7BC4CED1; Fri, 6 Dec 2024 15:26:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1733498772; bh=le7T2cfpLPHooxLTetQGbN+niTjmoardsw8qa5wNwZM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=w74k3owv/tVagVs4D1hg0IbMtLzV9220fgIDLt5zaYlZZ9ItJVfcMx7XV7rEcYkO3 KCsi2jBvcV/NrTQZCZk7v0EfLr5d8J7I9Oq5DZSxrdbZ5mkVDufgp3rEoKRwohJlQd /6u2LdziiSrOGVPoCfpe9xViHNrxw/mfCOxwfiKk= 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 6.6 662/676] powerpc: Fix stack protector Kconfig test for clang Date: Fri, 6 Dec 2024 15:38:01 +0100 Message-ID: <20241206143719.226477402@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241206143653.344873888@linuxfoundation.org> References: <20241206143653.344873888@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 6.6-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 @@ -271,8 +271,8 @@ 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