lkml.org 
[lkml]   [2002]   [Sep]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[patch] wait4-fix-2.5.34-A0, BK-curr

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)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:28    [W:0.026 / U:11.668 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site