the attached patch (against BK-curr) fixes a sys_wait4() bug noticed by
Ulrich Drepper. The kernel would not block properly if there are eligible
children delayed due to the new delayed thread-group-leader logic. The
solution is to introduce a new type of 'eligible child' type - and skip
over delayed children but set the wait4 flag nevertheless.
The libpthreads testcase that failed due to it now it works fine.
Ingo
--- linux/kernel/exit.c.orig Sun Sep 15 09:29:51 2002
+++ linux/kernel/exit.c Sun Sep 15 09:26:42 2002
@@ -731,7 +731,7 @@
* in a non-empty thread group:
*/
if (current->tgid != p->tgid && delay_group_leader(p))
- return 0;
+ return 2;
if (security_ops->task_wait(p))
return 0;
@@ -757,11 +757,21 @@
do {
struct task_struct *p;
struct list_head *_p;
+ int ret;
+
list_for_each(_p,&tsk->children) {
p = list_entry(_p,struct task_struct,sibling);
- if (!eligible_child(pid, options, p))
+
+ ret = eligible_child(pid, options, p);
+ if (!ret)
continue;
flag = 1;
+ /*
+ * Eligible but we cannot release it yet:
+ */
+ if (ret == 2)
+ continue;
+
switch (p->state) {
case TASK_STOPPED:
if (!p->exit_code)
-
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This archive was generated by hypermail 2b29 : Sun Sep 15 2002 - 22:00:37 EST