The patch titled
Subject: proc-report-eip-and-esp-for-all-threads-when-coredumping-fix-2
has been added to the -mm tree. Its filename is
proc-report-eip-and-esp-for-all-threads-when-coredumping-fix-2.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/proc-report-eip-and-esp-for-all-threads-when-coredumping-fix-2.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/proc-report-eip-and-esp-for-all-threads-when-coredumping-fix-2.patch
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------------------------------------------------------
From: John Ogness <john.ogness@xxxxxxxxxxxxx>
Subject: proc-report-eip-and-esp-for-all-threads-when-coredumping-fix-2
> * a program is not able to use ptrace(2) in that case. It is
> * safe because the task has stopped executing permanently.
> */
> - if (permitted && (task->flags & PF_DUMPCORE)) {
> + if (permitted && (!!mm->core_state)) {
This is not entirely safe. mm->core_state is set _before_ zap_process()
is called. Therefore tasks can be executing on a CPU with mm->core_state
set.
With the following additional change, I was able to close the window.
Link: http://lkml.kernel.org/r/875zpzif8v.fsf@xxxxxxxxxxxxx
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Jan Luebbe <jlu@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/coredump.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/coredump.c~proc-report-eip-and-esp-for-all-threads-when-coredumping-fix-2
+++ a/fs/coredump.c
@@ -340,10 +340,10 @@ static int zap_threads(struct task_struc
spin_lock_irq(&tsk->sighand->siglock);
if (!signal_group_exit(tsk->signal)) {
- mm->core_state = core_state;
tsk->signal->group_exit_task = tsk;
nr = zap_process(tsk, exit_code, 0);
clear_tsk_thread_flag(tsk, TIF_SIGPENDING);
+ mm->core_state = core_state;
}
spin_unlock_irq(&tsk->sighand->siglock);
if (unlikely(nr < 0))
_
Patches currently in -mm which might be from john.ogness@xxxxxxxxxxxxx are
proc-report-eip-and-esp-for-all-threads-when-coredumping-fix-2.patch
