From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric W. Biederman" Date: Thu, 05 May 2022 17:53:45 +0000 Subject: Re: [PATCH v3 08/11] ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs Message-Id: <87zgjv6f2u.fsf@email.froward.int.ebiederm.org> List-Id: References: <87k0b0apne.fsf_-_@email.froward.int.ebiederm.org> <20220504224058.476193-8-ebiederm@xmission.com> <20220505152801.GC13929@redhat.com> In-Reply-To: <20220505152801.GC13929@redhat.com> (Oleg Nesterov's message of "Thu, 5 May 2022 17:28:03 +0200") MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Oleg Nesterov Cc: linux-kernel@vger.kernel.org, rjw@rjwysocki.net, mingo@kernel.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, mgorman@suse.de, bigeasy@linutronix.de, Will Deacon , tj@kernel.org, linux-pm@vger.kernel.org, Peter Zijlstra , Richard Weinberger , Anton Ivanov , Johannes Berg , linux-um@lists.infradead.org, Chris Zankel , Max Filippov , linux-xtensa@linux-xtensa.org, Kees Cook , Jann Horn , linux-ia64@vger.kernel.org Oleg Nesterov writes: > On 05/04, Eric W. Biederman wrote: >> >> -static int ptrace_stop(int exit_code, int why, int clear_code, >> - unsigned long message, kernel_siginfo_t *info) >> +static int ptrace_stop(int exit_code, int why, unsigned long message, >> + kernel_siginfo_t *info) > > Forgot to mention... but in general I like this change. > > In particular, I like the fact it kills the ugly "int clear_code" arg > which looks as if it solves the problems with the exiting tracer, but > actually it doesn't. And we do not really care, imo. Further either this change is necessary or we need to take siglock in the !current->ptrace path in "ptrace: Don't change __state" so that JOBCTL_TRACED can be cleared. So I vote for deleting code, and making ptrace_stop easier to reason about. Eric