On Thu, Mar 07, 2002 at 01:43:54PM +0000, Alan Cox wrote:
> > I just upgraded from 2.4.8-pre3-ac2 to 2.4.19-pre2-ac2, and found that
> > for threaded programs like mozilla and xmms, files in /proc/<pid> are
> > owned by root, even if the process belongs to another user. I
> > particularly wanted to be able to read /proc/<pid>/environ, but I can't.
> >
> > [ ... ]
>
> Thanks - that will really help. There are several sets of thread related
> changes in -ac. Its all working for me however 8)
Ok, I found the responsible hunk, though I haven't any idea why it would
make a difference:
diff -durp linux-2.4.18-pre7-ac2/kernel/kmod.c linux-2.4.18-pre7-ac3/kernel/kmod.c
--- linux-2.4.18-pre7-ac2/kernel/kmod.c Tue Jul 17 18:23:50 2001
+++ linux-2.4.18-pre7-ac3/kernel/kmod.c Thu Mar 7 23:05:34 2002
@@ -111,15 +111,8 @@ int exec_usermodehelper(char *program_pa
if (curtask->files->fd[i]) close(i);
}
- /* Drop the "current user" thing */
- {
- struct user_struct *user = curtask->user;
- curtask->user = INIT_USER;
- atomic_inc(&INIT_USER->__count);
- atomic_inc(&INIT_USER->processes);
- atomic_dec(&user->processes);
- free_uid(user);
- }
+ /* Become root */
+ set_user(0, 1);
/* Give kmod all effective privileges.. */
curtask->euid = curtask->fsuid = 0;
This hunk shows up for the first time in 2.4.18-pre7-ac3, which shows
the behavior, while prior versions do not. If I revert this hunk from
ac3, I get the behavior I expect. It also fixes my problem when I
revert this from 2.4.19-pre2-ac2, which is where I first saw the
problems.
I don't see why mozilla would even touch this path of execution, so I
don't know why it would make a difference there, but it makes some sense
in the case of xmms, as my sound support is in modules. But it shows up
both places.
I also checked to see if the CLONE_THREAD change in kernel/fork.c in the
same patch had any effect, because that looked more relevant to
threading, but it didn't.
So now I guess I get to help you reproduce it on your end. Let me know
what you need from me.
Thanks,
Danek
-
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This archive was generated by hypermail 2b29 : Fri Mar 15 2002 - 22:00:07 EST