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Biederman" , Alexey Gladkov , Ran Xiaokai , Xiaofeng Cao , Cyrill Gorcunov , Thomas Cedeno , Marco Elver , Alexander Potapenko , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Evgenii Stepanov Subject: Re: [PATCH] kernel: introduce prctl(PR_LOG_UACCESS) Message-ID: References: <20210922061809.736124-1-pcc@google.com> <29f1822d-e4cd-eedb-bea8-619db1d56335@redhat.com> <20210922152250.4e7c869a@gandalf.local.home> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210922152250.4e7c869a@gandalf.local.home> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Sep 22, 2021 at 03:22:50PM -0400, Steven Rostedt wrote: > On Wed, 22 Sep 2021 19:46:47 +0200 > David Hildenbrand wrote: > > > > All signals except SIGKILL and SIGSTOP are masked for the interval > > > between the prctl() and the next syscall in order to prevent handlers > > > for intervening asynchronous signals from issuing syscalls that may > > > cause uaccesses from the wrong syscall to be logged. > > > > Stupid question: can this be exploited from user space to effectively > > disable SIGKILL for a long time ... and do we care? > > I first misread it too, but then caught my mistake reading it a second > time. It says "except SIGKILL". So no, it does not disable SIGKILL. Disabling SIGINT might already be a giant nuisance. Letting through SIGSTOP but not SIGCONT seems awkward. Blocking SIGTRAP seems like a bad idea too. Blocking SIGBUS as delivered by #MC will be hillarious. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel