Messages in this thread Patch in this message | | | Date | Tue, 3 Jan 2012 15:29:41 +0100 | From | Oleg Nesterov <> | Subject | Re: Possible bug introduced in commit 9b84cca |
| |
On 12/29, Oleg Nesterov wrote: > > On 12/29, Oleg Nesterov wrote: > > > > On 12/28, Denys Vlasenko wrote: > > > > > > 931 clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0xf763dbd8) = 1048 > > > 1048 exit_group(42) = ? > > > 931 waitpid(1048, <unfinished ...> > > > 1048 +++ exited with 42 +++ > > > 931 <... waitpid resumed> 0xf763d3a0, 0) = -1 ECHILD (No child processes) > > > I've made the simple test-case, it triggers the bug.
I am going to send the hack^Wpatch below to Linus as a temporary workaround for 3.2.
Any chance you can test it?
I did the testing too with my test-case, but it would be nice to know if it works for you.
Thanks,
Oleg.
--- x/kernel/exit.c~ 2011-11-22 18:46:22.000000000 +0100 +++ x/kernel/exit.c 2012-01-03 14:37:17.000000000 +0100 @@ -1540,8 +1540,11 @@ static int wait_consider_task(struct wai } /* dead body doesn't have much to contribute */ - if (p->exit_state == EXIT_DEAD) + if (unlikely(p->exit_state == EXIT_DEAD)) { + if (likely(!ptrace) && unlikely(ptrace_reparented(p))) + wo->notask_error = 0; return 0; + } /* slay zombie? */ if (p->exit_state == EXIT_ZOMBIE) {
| |