[patch 63/87] ptrace: kill __ptrace_detach(), fix ->exit_state check

Greg KH
2009-06-09T10:32:33Z

[-- Attachment #1: ptrace-kill-__ptrace_detach-fix-exit_state-check.patch --]
[-- Type: text/plain, Size: 1844 bytes --]

2.6.29-stable review patch. If anyone has any objections, please let us know.

------------------

From: Oleg Nesterov <oleg@redhat.com>

commit 95c3eb76dc07fd81289888ffc42948196b34b444 upstream.

Move the code from __ptrace_detach() to its single caller and kill this
helper.

Also, fix the ->exit_state check, we shouldn't wake up EXIT_DEAD tasks.
Actually, I think task_is_stopped_or_traced() makes more sense, but this
needs another patch.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
kernel/ptrace.c | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)

--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -235,16 +235,6 @@ out:
return retval;
}

-static inline void __ptrace_detach(struct task_struct *child, unsigned int data)
-{
- child->exit_code = data;
- /* .. re-parent .. */
- __ptrace_unlink(child);
- /* .. and wake it up. */
- if (child->exit_state != EXIT_ZOMBIE)
- wake_up_process(child);
-}
-
int ptrace_detach(struct task_struct *child, unsigned int data)
{
if (!valid_signal(data))
@@ -254,10 +244,16 @@ int ptrace_detach(struct task_struct *ch
ptrace_disable(child);
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

- write_lock_irq(&tasklist_lock);
/* protect against de_thread()->release_task() */
- if (child->ptrace)
- __ptrace_detach(child, data);
+ write_lock_irq(&tasklist_lock);
+ if (child->ptrace) {
+ child->exit_code = data;
+
+ __ptrace_unlink(child);
+
+ if (!child->exit_state)
+ wake_up_process(child);
+ }
write_unlock_irq(&tasklist_lock);

return 0;