Now we can kill ->ptrace check in ptrace_attach_task(), if the task is
not dead we always clear ->ptrace before UTRACE_DETACH.
This reverts most part of
"[PATCH 09] move ->ptrace == 0 checks to ptrace_attach_task()", but
I am just sending the new patch on top of previous changes to avoid
the confusion.
---
kernel/ptrace.c | 39 +++++++++++++--------------------------
1 file changed, 13 insertions(+), 26 deletions(-)
--- PU/kernel/ptrace.c~14_ATTACH_DONT_CK_PTRACE 2009-08-22 20:31:26.000000000
+0200
+++ PU/kernel/ptrace.c 2009-08-22 20:46:41.000000000 +0200
@@ -485,43 +485,30 @@ static int ptrace_attach_task(struct tas
{
struct utrace_engine *engine;
unsigned long events;
- int err = -EPERM;
engine = utrace_attach_task(tracee, UTRACE_ATTACH_CREATE |
UTRACE_ATTACH_EXCLUSIVE |
UTRACE_ATTACH_MATCH_OPS,
&ptrace_utrace_ops, NULL);
if (unlikely(IS_ERR(engine))) {
- if (PTR_ERR(engine) == -ESRCH ||
- PTR_ERR(engine) == -ERESTARTNOINTR)
- err = PTR_ERR(engine);
+ int err = PTR_ERR(engine);
+ if (err != -ESRCH && err != -ERESTARTNOINTR)
+ err = -EPERM ;
return err;
}
-
/*
- * Check ->ptrace to make sure we don't race with the previous
- * tracer which didn't finish detach. If it is clear, nobody
- * can change it except us due to UTRACE_ATTACH_EXCLUSIVE.
+ * We need QUIESCE for resume handling, CLONE to check
+ * for CLONE_PTRACE, other events are always reported.
*/
- if (unlikely(tracee->ptrace)) {
- utrace_control(tracee, engine, UTRACE_DETACH);
- } else {
- /*
- * We need QUIESCE for resume handling, CLONE to check
- * for CLONE_PTRACE, other events are always reported.
- */
- events = UTRACE_EVENT(QUIESCE) | UTRACE_EVENT(CLONE) |
- UTRACE_EVENT(EXEC) | UTRACE_EVENT_SIGNAL_ALL;
- /*
- * It can fail only if the tracee is dead, the caller
- * must notice this before setting PT_PTRACED.
- */
- utrace_set_events(tracee, engine, events);
- err = 0;
- }
-
+ events = UTRACE_EVENT(QUIESCE) | UTRACE_EVENT(CLONE) |
+ UTRACE_EVENT(EXEC) | UTRACE_EVENT_SIGNAL_ALL;
+ /*
+ * It can fail only if the tracee is dead, the caller
+ * must notice this before setting PT_PTRACED.
+ */
+ utrace_set_events(tracee, engine, events);
utrace_engine_put(engine);
- return err;
+ return 0;
}
static void ptrace_abort_attach(struct task_struct *tracee)
