From nobody Sun Nov 24 23:34:14 2024 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 1BB021CB50D; Thu, 31 Oct 2024 19:21:45 +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=1730402505; cv=none; b=PY42mS2EibO2OCKTw0XKwiVv9Eg2ONQ9Z/DRQlkEXurzsIusUMNgvf0TAeYmFP++kRqFhvH26SyN4pMsTKp1VtPZwoPQcJntWThVSOqc9H/UXRFv3Lw2IZ09dzK54ujxLMF/Gqm3463LcHjsnKfuMERSmZpbvg2uS2oL+n03oMA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730402505; c=relaxed/simple; bh=0ZSgsybRkNgA//hqHaFbgWNG+1PnzRnJxZ3UfA4h9Rs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=baj/cIlTsE3+H0jT3h9LQrr7BeBMrYUtsmOHzq4yX+9I98SLUz6lzMDcbxSGRHLUb5DMtA3bQ/4ih6iWsYjGHbywS9JEoDlQJfIIpIZFXq2v35x3p9aAdkN58Wb7iwJ/f58+RMg435LMvo5DD4adLi1Cu8ocZs7QfP4vq7hEISo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jAotM7qd; 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="jAotM7qd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D72CC4CED3; Thu, 31 Oct 2024 19:21:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730402504; bh=0ZSgsybRkNgA//hqHaFbgWNG+1PnzRnJxZ3UfA4h9Rs=; h=From:Date:Subject:To:Cc:From; b=jAotM7qdJB81uguvOPNpxfpjVngo51BMHoiWwhXcNwIr86J2udKL3utXN7I8nPX9D 0i5FNYPAvnweqqvT0bm0XYe1PtZ4mKOgF9eoqRskXUjc/MV0MJOAxvbjx8vDBLL7P1 IznFmDgKZJ7m4+clMiJKYbYRyJU4OKXSAaSTe6KFtu/wypGH16NGKR5dtJ8HUyWrwK hP1l9PZWShs9wx8rvpOQOXdW8JG7Xn42JrzsKZWz6Qs/Eue1hHS889sSa5NlOJYFPo bqg91tOQdWR2/9gmviQwUdmeISpwPXAxxQ35CttsiqQfOsDQ8Q+NPVHYR5rKsPIGtb UOSjGJZfOXQSg== From: Mark Brown Date: Thu, 31 Oct 2024 19:21:38 +0000 Subject: [PATCH] arm64/gcs: Fix outdated ptrace documentation Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20241031-arm64-gcs-doc-disable-v1-1-d7f6ded62046@kernel.org> X-B4-Tracking: v=1; b=H4sIAMHYI2cC/x3MwQqDMAyA4VeRnA0krp2wVxkeahtdwLWjARHEd 1/x+B3+/wSTqmLw6k6osqtpyQ3cdxA/Ia+CmpphoMExPRhD/T4drtEwlYhJLcyboDiKxOz9SAK t/VVZ9Li/7+m6/vrBbvZnAAAA X-Change-ID: 20241031-arm64-gcs-doc-disable-e40c0115570e To: Catalin Marinas , Will Deacon , Jonathan Corbet Cc: linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Mark Brown X-Mailer: b4 0.15-dev-9b746 X-Developer-Signature: v=1; a=openpgp-sha256; l=1804; i=broonie@kernel.org; h=from:subject:message-id; bh=0ZSgsybRkNgA//hqHaFbgWNG+1PnzRnJxZ3UfA4h9Rs=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBnI9jG+FCHClvg5NARf9CZ3l7Gnyt4LVv9jrok91J5 qnOg2QOJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZyPYxgAKCRAk1otyXVSH0GolB/ 9x7Rxxvu35bazi1kYivVoC5b5L6KYYjB5ulPK+yCDLHX1M2g2elshC33kBGGBQfzRF3JggFfO+88p8 n20h9PE6vHwLrVDuNFBtsQrhgsVJ/rw+HfLsPeYmQCRljuCtnUUcmGX23ZtPv6h3rfIYE2WJh+lqlj vZWgVQyxmUNdT+moVsN+2SRNllvrhzUVbob4Z2ynSYARcreMguOwoOJ3tGLUAYLxNjshJuKLVF/DcL 88+iglT8m6AMP5OQN0oWaVN14FBlUNvt8uL3JSwQaMEtO2wfKYq+r4HpnjmXb23NY7hbmSWihugV69 twT6cz31E1oSFzQJj4edC/qPaQK0Rz X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB The ptrace documentation for GCS was written prior to the implementation of clone3() when we still blocked enabling of GCS via ptrace. This restriction was relaxed as part of implementing clone3() support since we implemented support for the GCS not being managed by the kernel but the documentation still mentions the restriction. Update the documentation to reflect what was merged. We have not yet merged clone3() itself but all the support other than in clone() itself is there. Fixes: 7058bf87cd59 ("arm64/gcs: Document the ABI for Guarded Control Stack= s") Signed-off-by: Mark Brown --- Documentation/arch/arm64/gcs.rst | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/Documentation/arch/arm64/gcs.rst b/Documentation/arch/arm64/gc= s.rst index af58d9151cb72df9058ddccadb2602127b479c95..1f65a3193e7765dce9bfd6ad88b= 9fbd6a225ed86 100644 --- a/Documentation/arch/arm64/gcs.rst +++ b/Documentation/arch/arm64/gcs.rst @@ -204,11 +204,8 @@ When returning from a signal handler: * A new regset NT_ARM_GCS is defined for use with PTRACE_GETREGSET and PTRACE_SETREGSET. =20 -* Due to the complexity surrounding allocation and deallocation of stacks = and - lack of practical application it is not possible to enable GCS via ptrac= e. - GCS may be disabled via the ptrace interface. - -* Other GCS modes may be configured via ptrace. +* The GCS mode, including enable and disable, may be configured via ptrace. + If GCS is enabled via ptrace no new GCS will be allocated for the thread. =20 * Configuration via ptrace ignores locking of GCS mode bits. =20 --- base-commit: 9b9be78258511e67767e4aa51f587cf22feb5065 change-id: 20241031-arm64-gcs-doc-disable-e40c0115570e Best regards, --=20 Mark Brown