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b=iHO6hjlz+1cwRAj11Z0BXNSd3Yq6BnEvTZZoGBv1qhp1x7HGDkemndDVxEVMG7J51 Gdz8SwuQ/BfwAbWyCiYidSR2UDQ8QAqPcH9HdtDm/2jxHoLBUzwTVRM7XcSbmTizht zFfSspDks1KDLvwhuUv/HuWhPE3wHyi9+vVVOVF8kNgqdHL8TT40qZKa8oUL4EBss+ tPpud4BB3rowu/lvm+SvsrUDIiyFr5FClJMP8DTtafe3fbi9ktfvQz/3x7HXc1hfeg aXZFxzbBZ3tECD9sDCGGU5caeLzmpy2hjygUe9YclZaeK8hYsEZn2fVE0Ae5Yz51zO rZA0wkMlJdM/Q== Date: Wed, 6 Nov 2024 11:06:10 +0100 From: Christian Brauner To: Tycho Andersen Cc: Alexander Viro , Jan Kara , Eric Biederman , Kees Cook , Shuah Khan , Zbigniew =?utf-8?Q?J=C4=99drzejewski-Szmek?= , Aleksa Sarai , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Tycho Andersen Subject: Re: [PATCH 1/2] exec: fix up /proc/pid/comm in the execveat(AT_EMPTY_PATH) case Message-ID: <20241106-neukauf-befugnis-a54d08ac9b4b@brauner> References: <20241030203732.248767-1-tycho@tycho.pizza> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20241030203732.248767-1-tycho@tycho.pizza> X-Rspamd-Server: rspam10 X-Stat-Signature: 1cx1ahycykz7fxe11f8ajymkjfho6o1g X-Rspamd-Queue-Id: 0EF35180010 X-Rspam-User: X-HE-Tag: 1730887543-293613 X-HE-Meta: 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 jq0Rhfqn 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000004, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Oct 30, 2024 at 02:37:31PM -0600, Tycho Andersen wrote: > From: Tycho Andersen > > Zbigniew mentioned at Linux Plumber's that systemd is interested in > switching to execveat() for service execution, but can't, because the > contents of /proc/pid/comm are the file descriptor which was used, > instead of the path to the binary. This makes the output of tools like > top and ps useless, especially in a world where most fds are opened > CLOEXEC so the number is truly meaningless. > > Change exec path to fix up /proc/pid/comm in the case where we have > allocated one of these synthetic paths in bprm_init(). This way the actual > exec machinery is unchanged, but cosmetically the comm looks reasonable to > admins investigating things. > > Signed-off-by: Tycho Andersen > Suggested-by: Zbigniew Jędrzejewski-Szmek > CC: Aleksa Sarai > Link: https://github.com/uapi-group/kernel-features#set-comm-field-before-exec > --- We finally went full circle back to what was originally proposed :) Reviewed-by: Christian Brauner