Re: [PATCH] reboot: log the task that requested a reboot or shutdown

[Bradley Morgan]

On July 19, 2026 4:29:09 PM GMT+01:00, Bradley Morgan <include@xxxxxxxxx>
wrote:
>When a machine reboots or powers off, the kernel log records what
>happened but not who asked for it.  The reboot syscall throws the
>caller identity away, and reconstructing it afterwards from userspace
>logs is unreliable and more likely than not impossible.
>"What made this reboot?" is a question every fleet operator has had to
>answer with guesswork.
>
>log the comm and pid of the calling task once at the syscall boundary,
>before the requested command is carried out, e.g:
>
>  reboot: initiated by systemd-shutdow[1]
>  reboot: Restarting system
>
>The existing "Restarting system", "System halted" and "Power down"
>lines are left untouched, so anything parsing dmesg today keeps
>working. The two ctrl alt del toggle commands are excluded so init
>setting the mode does not add a line to dmesg on every boot.
>
>Signed-off-by: Bradley Morgan <include@xxxxxxxxx>
>---
> kernel/reboot.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
>diff --git a/kernel/reboot.c b/kernel/reboot.c
>index c10ac6a0200d..8ac96c527a4e 100644
>--- a/kernel/reboot.c
>+++ b/kernel/reboot.c
>@@ -754,6 +754,10 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
> 	if (ret)
> 		return ret;
> 
>+	if (cmd != LINUX_REBOOT_CMD_CAD_ON && cmd != LINUX_REBOOT_CMD_CAD_OFF)
>+		pr_info("initiated by %s[%d]\n",
>+			current->comm, task_pid_nr(current));
>+
> 	/* Instead of trying to make the power_off code look like
> 	 * halt when pm_power_off is not set do it the easy way.
> 	 */
>
Sashiko said something:
https://sashiko.dev/#/patchset/20260719152909.3133-1-include%40grrlz.net


Sashiko is correct, my bad.

Sending V2 that should fix it.
Thanks!