support: Add check for TID zero in support_wait_for_thread_exit

Some kernel versions (observed with kernel 5.14 and earlier) can list
"0" entries in /proc/self/task.  This happens when a thread exits
while the task list is being constructed.  Treat this entry as not
present, like the proposed kernel patch does:

[PATCH] procfs: Do not list TID 0 in /proc/<pid>/task
<https://lore.kernel.org/all/8735pn5dx7.fsf@oldenburg.str.redhat.com/>

Fixes commit 032d74eaf6 ("support: Add
support_wait_for_thread_exit").

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This commit is contained in:
Florian Weimer 2021-10-01 18:16:41 +02:00
parent 2313ab153d
commit 176c88f521

View File

@ -43,7 +43,10 @@ support_wait_for_thread_exit (void)
return;
}
if (strcmp (e->d_name, ".") == 0 || strcmp (e->d_name, "..") == 0)
/* In some kernels, "0" entries denote a thread that has just
exited. */
if (strcmp (e->d_name, ".") == 0 || strcmp (e->d_name, "..") == 0
|| strcmp (e->d_name, "0") == 0)
continue;
int task_tid = atoi (e->d_name);