From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lj1-f172.google.com (mail-lj1-f172.google.com [209.85.208.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E9FA669311 for ; Wed, 21 Feb 2024 12:39:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708519168; cv=none; b=IlB9VJG/dHo7o+WyO0bvnyLMQMH8DB5f/HV4oTWP/R5fyIb3E2/V1ufLyW18I4Zr8XBDgG9wNUqSra27OSekR7ESK0SLfWLPZSh+Eg+rZ5bXDdxQWd/SkRz4Lf0zIW/FcgcN07lme6ErIqN07+9rmg0CfOu7UEJNxJxL7WczXfQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708519168; c=relaxed/simple; bh=Lu9vnZh6Un3N+32ujmPjCZoYI/iNGYkpy/wvhMoT3ts=; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type; b=J7IcrbS+3mlZKKni9V/FAZuf3//3CiZWpWyHlRZ6Dvymjm39w0W9vTFA6cHacauX59OIdf8bT1CoRf5PtJ/eU4ynOhJeP0U2xkJdOfNjqWr2kmXHwBdp0L8ICSMoqA/ucnrxh1rVIgcsrcB/6jTcgkpFSlZnU/P6uwoh153S8y8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=FeUdpVnz; arc=none smtp.client-ip=209.85.208.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="FeUdpVnz" Received: by mail-lj1-f172.google.com with SMTP id 38308e7fff4ca-2d094bc2244so90723901fa.1 for ; Wed, 21 Feb 2024 04:39:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1708519165; x=1709123965; darn=vger.kernel.org; h=content-language:thread-index:content-transfer-encoding :mime-version:message-id:date:subject:to:from:from:to:cc:subject :date:message-id:reply-to; bh=Lu9vnZh6Un3N+32ujmPjCZoYI/iNGYkpy/wvhMoT3ts=; b=FeUdpVnzzqAn2JiZxJS2g+b+MMCt3tDAfRiPTInhIAk99LxYMM6O515EQ7LmncJCCR oFEQ+csZCZFTOXPIUq2Wo6R5Fc7TkSIrp5CwZdauOIGxKEBuMaveBtbW0cjNTnmIR683 Qt7u0jm1PyV9K115xKGg4AOQwGKXuCwTmt9xpZCgulycDlyJ+WGPakoYEfo/0TEPoozi hUxdUfA7CO8lARu+hSXkIhqRSJN3yGkG7jnSNMfPQ8vNNDWLGgIs4Jy0tN2d4UCp0Pnf 1Ac4SCMvVPy3jxHuY5Z7wEiDUbOvZcZgrqJT6qI6Ig2VPYLm/nCqsd7vmhXlUm6FXhi2 pSow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1708519165; x=1709123965; h=content-language:thread-index:content-transfer-encoding :mime-version:message-id:date:subject:to:from:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=Lu9vnZh6Un3N+32ujmPjCZoYI/iNGYkpy/wvhMoT3ts=; b=LjW3JZUkOa5uj1zuwppFLU0uDOc07ywjGuL4p7pWgEMRIDbCa+r+zPv9sjWOchxc/l +xk53Vv/8vzBiEorqSUabafDodOW4l/bbIp52wZtHoF5nGGRGmSNkfBWKk7ro4oG9wZw EDT/Iw9HXKwsGB65+bVczQfnbcjkvdHKsp+T3gQ5W+WYp9UO4DLTgfD/ajvcNT1K/w/x 5N51pfzpOJYxWjzhyfLHKsBCpJBqPTV3EkOUy/tgP1CuVbT4t8rYILxdouXBwM5/i8iq Xy8kKxhV2nH3jXYuB1DZaNa0SaKinr6eRAcYMEO+HUYeLkVy0Zpe6VvX8QQLHPDTg3OV 7bAw== X-Gm-Message-State: AOJu0Yz1pqJIHEcgZS/ucA9ecEv+lqXUN7n6bb14RQjyQNd3Swth0wi2 yMXdreQyW1wbGzScg+ZdhZ1QWmdlWj3F6RCoJVq//f+/7qEqbgWzh4jrNISA X-Google-Smtp-Source: AGHT+IH9JjUILXXO8LB/roF+pvn4nPu+dvs3PtSJYKHYlyf45TTtHB10EjtIjq082ZqVswlkTsgEEQ== X-Received: by 2002:a05:651c:1056:b0:2d2:39b5:6f6 with SMTP id x22-20020a05651c105600b002d239b506f6mr5528169ljm.28.1708519164770; Wed, 21 Feb 2024 04:39:24 -0800 (PST) Received: from LAPTOPVHVOIDM6 (82-69-18-221.dsl.in-addr.zen.co.uk. [82.69.18.221]) by smtp.gmail.com with ESMTPSA id bx14-20020a5d5b0e000000b0033d6bd4eab9sm5574038wrb.1.2024.02.21.04.39.24 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 21 Feb 2024 04:39:24 -0800 (PST) From: To: Subject: ptrace: Why does PTRACE_PEEKUSER not allow reading of FPU registers on x86? Date: Wed, 21 Feb 2024 12:39:23 -0000 Message-ID: <01a401da64c3$0027ce60$00776b20$@gmail.com> 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="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Outlook 16.0 Thread-Index: AdpkwZkfG+dcZKICSg+ZwUobaTP6Ew== Content-Language: en-gb Hey folks, Looking at arch/x86/kernel/ptrace.c, I can see that reading with PTRACE_PEEKUSER is only supported within the user::regs and user::u_debugreg fields. What's the reason that reading from user::i387 is disallowed? Thanks, Sy Brand