Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.32 as permitted sender) client-ip=23.128.96.32;
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 <thiago.bauermann@linaro.org>
To:     Mark Brown <broonie@kernel.org>
Cc:     Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        Marc Zyngier <maz@kernel.org>,
        Oliver Upton <oliver.upton@linux.dev>,
        James Morse <james.morse@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Arnd Bergmann <arnd@arndb.de>, Oleg Nesterov <oleg@redhat.com>,
        Eric Biederman <ebiederm@xmission.com>,
        Kees Cook <keescook@chromium.org>,
        Shuah Khan <shuah@kernel.org>,
        "Rick P. Edgecombe" <rick.p.edgecombe@intel.com>,
        Deepak Gupta <debug@rivosinc.com>,
        Ard Biesheuvel <ardb@kernel.org>,
        Szabolcs Nagy <Szabolcs.Nagy@arm.com>,
        "H.J. Lu" <hjl.tools@gmail.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Florian Weimer <fweimer@redhat.com>,
        Christian Brauner <brauner@kernel.org>,
        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>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk


Mark Brown <broonie@kernel.org> 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