Copy-and-paste.
Roland, ptrace_check_attach()->utrace_control(UTRACE_STOP) is not right.
We should not do mark_engine_wants_stop() and set ->report from
ptrace_check_attach(). It should be "passive", except s/STOPPED/TRACED/.
for this series this is not right too...
---
kernel/ptrace.c | 42 ++++++++++++++++++------------------------
1 file changed, 18 insertions(+), 24 deletions(-)
--- MINI/kernel/ptrace.c~4_CK_ATTACH 2009-08-25 17:41:47.000000000 +0200
+++ MINI/kernel/ptrace.c 2009-08-25 17:54:50.000000000 +0200
@@ -159,35 +159,29 @@ void __ptrace_unlink(struct task_struct
*/
int ptrace_check_attach(struct task_struct *child, int kill)
{
- int ret = -ESRCH;
+ struct utrace_engine *engine;
+ struct utrace_examiner exam;
+ int ret;
+
+ if (child->parent != current)
+ return -ESRCH;
+
+ engine = utrace_attach_task(child, UTRACE_ATTACH_MATCH_OPS,
+ &ptrace_utrace_ops, NULL);
+ if (IS_ERR(engine))
+ return -ESRCH;
/*
- * We take the read lock around doing both checks to close a
- * possible race where someone else was tracing our child and
- * detached between these two checks. After this locked check,
- * we are sure that this is our traced child and that can only
- * be changed by us so it's not changing right after this.
+ * Make sure our engine has already stopped the child.
+ * Then wait for it to be off the CPU.
*/
- 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;
- spin_unlock_irq(&child->sighand->siglock);
- }
- read_unlock(&tasklist_lock);
+ ret = 0;
+ if (utrace_control(child, engine, UTRACE_STOP) ||
+ utrace_prepare_examine(child, engine, &exam))
+ ret = -ESRCH;
- if (!ret && !kill)
- ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH;
+ utrace_engine_put(engine);
- /* All systems go.. */
return ret;
}
