ptrace: ptrace_check_attach() should not do s/STOPPED/TRACED/
After "ptrace: Clean transitions between TASK_STOPPED and TRACED"
d79fdd6d96f46fabb779d86332e3677c6f5c2a4f, ptrace_check_attach()
should never see a TASK_STOPPED tracee and s/STOPPED/TRACED/ is
no longer legal. Add the warning.
Note: ptrace_check_attach() can be greatly simplified, in particular
it doesn't need tasklist. But I'd prefer another patch for that.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 4348586..20d5efd 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -112,16 +112,14 @@
*/
read_lock(&tasklist_lock);
if ((child->ptrace & PT_PTRACED) && child->parent == current) {
- ret = 0;
/*
* child->sighand can't be NULL, release_task()
* does ptrace_unlink() before __exit_signal().
*/
spin_lock_irq(&child->sighand->siglock);
- if (task_is_stopped(child))
- child->state = TASK_TRACED;
- else if (!task_is_traced(child) && !kill)
- ret = -ESRCH;
+ WARN_ON_ONCE(task_is_stopped(child));
+ if (task_is_traced(child) || kill)
+ ret = 0;
spin_unlock_irq(&child->sighand->siglock);
}
read_unlock(&tasklist_lock);