Re: [RESEND PATCH v2] mm/oom_killer: Add task UID to info message on an oom kill

[Rafael Aquini]

On Wed, Jun 12, 2019 at 01:57:53PM -0400, Joel Savitz wrote:
> In the event of an oom kill, useful information about the killed
> process is printed to dmesg. Users, especially system administrators,
> will find it useful to immediately see the UID of the process.
> 
> In the following example, abuse_the_ram is the name of a program
> that attempts to iteratively allocate all available memory until it is
> stopped by force.
> 
> Current message:
> 
> Out of memory: Killed process 35389 (abuse_the_ram)
> total-vm:133718232kB, anon-rss:129624980kB, file-rss:0kB,
> shmem-rss:0kB
> 
> Patched message:
> 
> Out of memory: Killed process 2739 (abuse_the_ram),
> total-vm:133880028kB, anon-rss:129754836kB, file-rss:0kB,
> shmem-rss:0kB, UID 0
> 
> 
> Suggested-by: David Rientjes <rientjes@xxxxxxxxxx>
> Signed-off-by: Joel Savitz <jsavitz@xxxxxxxxxx>
> ---
>  mm/oom_kill.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index 3a2484884cfd..af2e3faa72a0 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -874,12 +874,13 @@ static void __oom_kill_process(struct task_struct *victim, const char *message)
>  	 */
>  	do_send_sig_info(SIGKILL, SEND_SIG_PRIV, victim, PIDTYPE_TGID);
>  	mark_oom_victim(victim);
> -	pr_err("%s: Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
> +	pr_err("%s: Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB, UID %d\n",
>  		message, task_pid_nr(victim), victim->comm,
>  		K(victim->mm->total_vm),
>  		K(get_mm_counter(victim->mm, MM_ANONPAGES)),
>  		K(get_mm_counter(victim->mm, MM_FILEPAGES)),
> -		K(get_mm_counter(victim->mm, MM_SHMEMPAGES)));
> +		K(get_mm_counter(victim->mm, MM_SHMEMPAGES)),
> +		from_kuid(&init_user_ns, task_uid(victim)));
>  	task_unlock(victim);
>  
>  	/*
> -- 
> 2.18.1
> 
Acked-by: Rafael Aquini <aquini@xxxxxxxxxx>