From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="KfkCRa9f" Received: from mail-pl1-x633.google.com (mail-pl1-x633.google.com [IPv6:2607:f8b0:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2507810CC for ; Wed, 6 Dec 2023 13:27:28 -0800 (PST) Received: by mail-pl1-x633.google.com with SMTP id d9443c01a7336-1d075392ff6so2092455ad.1 for ; Wed, 06 Dec 2023 13:27:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1701898047; x=1702502847; darn=vger.kernel.org; h=mime-version:message-id:date:in-reply-to:subject:cc:to:from :user-agent:references:from:to:cc:subject:date:message-id:reply-to; bh=mbZzH+s3JDxV/sloks5umdqEjeI9fKLBWt3znOcMhGI=; b=KfkCRa9fM4NEjcL7Gb6xjuKXyCWeOKdTkvxTnIU2vfyNQLIfT+bqLIf95FhcEs4ds8 euAWcJSfqGg0++Cx3B1VK5K+aDVcjAENud+a3jBW8mQwIKhzC3pqP/6mlh6/ViYg6RNI TfoNWfLLnygj5WeFkf8OAdZkElskLMAG8ZIoOb+QDB2k80pgg1xWWs5JF+/jfpsS7ngj T9xzop2Sgq6RpYEmMhk/u/+uvYB96343esMMFdKGxQxW32dz70VcRHJWJM5tCZ3Ylbxx n4XG7YWO6HBNEU1x6DnB4NHSMOXJ0zXf7dNjvuVlNvXMcFVAMVY0Lp8qoxPUV4iGWHIq gceQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701898047; x=1702502847; h=mime-version:message-id:date:in-reply-to:subject:cc:to:from :user-agent:references:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=mbZzH+s3JDxV/sloks5umdqEjeI9fKLBWt3znOcMhGI=; b=QtZMwmvq9FUSVR9pXc8H4e/xB/PJtkQNKjJnqerfOHD4m1r0nfQWW2oAR16AT4/tJX nhmJgOkKUgGzR5IOJ8+nEmSFQ+hDURjs8Z8AhjGGGWVNRXFzP+69U9W8V1U8wnQMk6on PXFwMC5OkrPHWs9B7uokK7Oi4RDlvV8qpvnaZE8yrWvwR1pS3pwIMQAaS5OerHe8JkL1 eCYiJkmh4GtCrgECzGzHxJvw8O28O4Pjhtor5ibC+7TzImtWE845AYiF1i4r6ZoJ0xT0 FyFjhi1C3VhyGp4BJbYJ2xU+OyctmUYr5G3RoH3rY4mYDuuDJb987B3ZyCUyZQNIX5Fa sk6Q== X-Gm-Message-State: AOJu0YwcCjB/y5qovqAscKAlJujn4OFaRrlRovRa6IHij5zdoVJOhJhx bIKhA+iDBkPVX7nmMauYoZ+Iag== X-Google-Smtp-Source: AGHT+IGLa8DInnGMjJcXZtON7bZ8pQ8xN1J6vJzQP1zj6zdeB3quK1/DibmWAlo2/mpEotTdJ4e23w== X-Received: by 2002:a17:902:e80f:b0:1d0:6cfd:d3c4 with SMTP id u15-20020a170902e80f00b001d06cfdd3c4mr2193857plg.17.1701898047545; Wed, 06 Dec 2023 13:27:27 -0800 (PST) Received: from localhost ([2804:14d:7e22:803e:f0e2:3ff1:8acc:a2d5]) by smtp.gmail.com with ESMTPSA id jj12-20020a170903048c00b001cf6453b237sm259379plb.236.2023.12.06.13.27.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Dec 2023 13:27:27 -0800 (PST) References: <20231122-arm64-gcs-v7-0-201c483bd775@kernel.org> <20231122-arm64-gcs-v7-22-201c483bd775@kernel.org> User-agent: mu4e 1.10.8; emacs 29.1 From: Thiago Jung Bauermann To: Mark Brown Cc: Catalin Marinas , Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Kees Cook , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy , "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Florian Weimer , Christian Brauner , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH v7 22/39] arm64/gcs: Implement shadow stack prctl() interface In-reply-to: <20231122-arm64-gcs-v7-22-201c483bd775@kernel.org> Date: Wed, 06 Dec 2023 18:27:25 -0300 Message-ID: <87edfzhvia.fsf@linaro.org> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Mark Brown writes: > Implement the architecture neutral prtctl() interface for setting the > shadow stack status, this supports setting and reading the current GCS > configuration for the current thread. > > Userspace can enable basic GCS functionality and additionally also > support for GCS pushes and arbatrary GCS stores. It is expected that s/arbatrary/arbitrary/ > this prctl() will be called very early in application startup, for > example by the dynamic linker, and not subsequently adjusted during > normal operation. Users should carefully note that after enabling GCS > for a thread GCS will become active with no call stack so it is not > normally possible to return from the function that invoked the prctl(). -- Thiago