Re: [PATCH 1/2] exec: fix up /proc/pid/comm in the execveat(AT_EMPTY_PATH) case

[Christian Brauner]

On Wed, Oct 30, 2024 at 02:37:31PM -0600, Tycho Andersen wrote:
> From: Tycho Andersen <tandersen@xxxxxxxxxxx>
> 
> 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 <tandersen@xxxxxxxxxxx>
> Suggested-by: Zbigniew Jędrzejewski-Szmek <zbyszek@xxxxxxxxx>
> CC: Aleksa Sarai <cyphar@xxxxxxxxxx>
> 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 <brauner@xxxxxxxxxx>