On 21.10.2015 01:31, Andrew Morton wrote: > On Tue, 20 Oct 2015 19:17:54 +0200 Oleg Nesterov <[email protected]> wrote: > >> The following program (simplified version of generated by syzkaller) >> >> #include <pthread.h> >> #include <unistd.h> >> #include <sys/ptrace.h> >> #include <stdio.h> >> #include <signal.h> >> >> void *thread_func(void *arg) >> { >> ptrace(PTRACE_TRACEME, 0,0,0); >> return 0; >> } >> >> int main(void) >> { >> pthread_t thread; >> >> if (fork()) >> return 0; >> >> while (getppid() != 1) >> ; >> >> pthread_create(&thread, NULL, thread_func, NULL); >> pthread_join(thread, NULL); >> return 0; >> } >> >> creates the unreapable zombie if /sbin/init doesn't use __WALL. >> >> This is not a kernel bug, at least in a sense that everything works as >> expected: debugger should reap a traced sub-thread before it can reap >> the leader, but without __WALL/__WCLONE do_wait() ignores sub-threads. >> >> Unfortunately, it seems that /sbin/init in most (all?) distributions >> doesn't use it and we have to change the kernel to avoid the problem. > > Well, to fix this a distro needs to roll out a new kernel. Or a new > init(8). Is there any reason to believe that distributing/deploying a > new kernel is significantly easier for everyone? Because fixing init > sounds like a much preferable solution to this problem.
Patched kernel allows to run obsoleted distro inside containers. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
