The patch titled
ptrace: reintroduce __ptrace_detach() as a callee of ptrace_exit()
has been added to the -mm tree. Its filename is
ptrace-reintroduce-__ptrace_detach-as-a-callee-of-ptrace_exit.patch
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------------------------------------------------------
Subject: ptrace: reintroduce __ptrace_detach() as a callee of ptrace_exit()
From: Oleg Nesterov <oleg@xxxxxxxxxx>
No functional changes, preparation for the next patch.
Move the "should we release this child" logic into the separate handler,
__ptrace_detach().
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Jerome Marchand <jmarchan@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/exit.c | 63 +++++++++++++++++++++++++-----------------------
1 file changed, 34 insertions(+), 29 deletions(-)
diff -puN kernel/exit.c~ptrace-reintroduce-__ptrace_detach-as-a-callee-of-ptrace_exit kernel/exit.c
--- a/kernel/exit.c~ptrace-reintroduce-__ptrace_detach-as-a-callee-of-ptrace_exit
+++ a/kernel/exit.c
@@ -737,6 +737,39 @@ static int ignoring_children(struct sigh
sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT;
}
+/* Returns nonzero if the tracee should be released. */
+int __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
+{
+ __ptrace_unlink(p);
+
+ if (p->exit_state != EXIT_ZOMBIE)
+ return 0;
+ /*
+ * If it's a zombie, our attachedness prevented normal
+ * parent notification or self-reaping. Do notification
+ * now if it would have happened earlier. If it should
+ * reap itself, add it to the @dead list. We can't call
+ * release_task() here because we already hold tasklist_lock.
+ *
+ * If it's our own child, there is no notification to do.
+ * But if our normal children self-reap, then this child
+ * was prevented by ptrace and we must reap it now.
+ */
+ if (!task_detached(p) && thread_group_empty(p)) {
+ if (!same_thread_group(p->real_parent, tracer))
+ do_notify_parent(p, p->exit_signal);
+ else if (ignoring_children(tracer->sighand))
+ p->exit_signal = -1;
+ }
+
+ if (!task_detached(p))
+ return 0;
+
+ /* Mark it as in the process of being reaped. */
+ p->exit_state = EXIT_DEAD;
+ return 1;
+}
+
/*
* Detach all tasks we were using ptrace on.
* Any that need to be release_task'd are put on the @dead list.
@@ -748,36 +781,8 @@ static void ptrace_exit(struct task_stru
struct task_struct *p, *n;
list_for_each_entry_safe(p, n, &parent->ptraced, ptrace_entry) {
- __ptrace_unlink(p);
-
- if (p->exit_state != EXIT_ZOMBIE)
- continue;
-
- /*
- * If it's a zombie, our attachedness prevented normal
- * parent notification or self-reaping. Do notification
- * now if it would have happened earlier. If it should
- * reap itself, add it to the @dead list. We can't call
- * release_task() here because we already hold tasklist_lock.
- *
- * If it's our own child, there is no notification to do.
- * But if our normal children self-reap, then this child
- * was prevented by ptrace and we must reap it now.
- */
- if (!task_detached(p) && thread_group_empty(p)) {
- if (!same_thread_group(p->real_parent, parent))
- do_notify_parent(p, p->exit_signal);
- else if (ignoring_children(parent->sighand))
- p->exit_signal = -1;
- }
-
- if (task_detached(p)) {
- /*
- * Mark it as in the process of being reaped.
- */
- p->exit_state = EXIT_DEAD;
+ if (__ptrace_detach(parent, p))
list_add(&p->ptrace_entry, dead);
- }
}
}
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
linux-next.patch
wait-prevent-exclusive-waiter-starvation.patch
pipe_rdwr_fasync-fix-the-error-handling-to-prevent-the-leak-crash.patch
get_mm_hiwater_xxx-trivial-s-define-inline.patch
getrusage-fill-ru_maxrss-value.patch
ptrace-kill-__ptrace_detach-fix-exit_state-check.patch
ptrace-simplify-ptrace_exit-ignoring_children-path.patch
ptrace-reintroduce-__ptrace_detach-as-a-callee-of-ptrace_exit.patch
ptrace-fix-possible-zombie-leak-on-ptrace_detach.patch
kthread-dont-looking-for-a-task-in-create_kthread-2.patch
pids-document-task_pgrp-task_session-is-not-safe-without-tasklist-rcu.patch
pids-document-task_pgrp-task_session-is-not-safe-without-tasklist-rcu-fix.patch
pids-improve-get_task_pid-to-fix-the-unsafe-sys_wait4-task_pgrp.patch
pids-refactor-vnr-nr_ns-helpers-to-make-them-safe.patch
pids-kill-now-unused-signal_struct-__pgrp-__session-and-friends.patch
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