Asking wait_task_inactive to verify that tsk->__state == __TASK_TRACED
was needed to detect the when ptrace_stop would decide not to stop
after calling "set_special_state(TASK_TRACED)". With the recent
cleanups ptrace_stop will always stop after calling set_special_state.
Take advatnage of this by no longer asking wait_task_inactive to
verify the state. If a bug is hit and wait_task_inactive does not
succeed warn and return -ESRCH.
Signed-off-by: "Eric W. Biederman" <ebied...@xmission.com>
---
kernel/ptrace.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 16d1a84a2cae..0634da7ac685 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -265,17 +265,9 @@ static int ptrace_check_attach(struct task_struct *child,
bool ignore_state)
}
read_unlock(&tasklist_lock);
- if (!ret && !ignore_state) {
- if (!wait_task_inactive(child, __TASK_TRACED)) {
- /*
- * This can only happen if may_ptrace_stop() fails and
- * ptrace_stop() changes ->state back to TASK_RUNNING,
- * so we should not worry about leaking __TASK_TRACED.
- */
- WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED);
- ret = -ESRCH;
- }
- }
+ if (!ret && !ignore_state &&
+ WARN_ON_ONCE(!wait_task_inactive(child, 0)))
+ ret = -ESRCH;
return ret;
}
--
2.35.3
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