From: Joel Savitz <jsavitz@xxxxxxxxxx> Subject: mm/oom_kill.c: add task UID to info message on an oom kill 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. We already print uid when dumping eligible tasks so it is not overly hard to find that information in the oom report. However this information is unavailable when dumping of eligible tasks is disabled. 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 [akpm@xxxxxxxxxxxxxxxxxxxx: s/UID %d/UID:%u/ in printk] Link: http://lkml.kernel.org/r/1560362273-534-1-git-send-email-jsavitz@xxxxxxxxxx Signed-off-by: Joel Savitz <jsavitz@xxxxxxxxxx> Suggested-by: David Rientjes <rientjes@xxxxxxxxxx> Acked-by: Rafael Aquini <aquini@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/oom_kill.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/mm/oom_kill.c~mm-oom_killer-add-task-uid-to-info-message-on-an-oom-kill +++ a/mm/oom_kill.c @@ -884,12 +884,13 @@ static void __oom_kill_process(struct ta */ 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:%u\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); /* _
