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| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2015-02-02 11:47:31 -0500 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2015-02-02 11:47:31 -0500 |
| commit | dfbc1534eac550b37df592a8a0b550cd47539d0b (patch) | |
| tree | ec2f50ac271be0bad556e5e22a204bddc1f63a9a /kernel/exit.c | |
| parent | 7eeafbcab47fe9860e5106286db83d60e3f35644 (diff) | |
| parent | 163f9eb95a10371ead59b62087e0d4e7ce53112e (diff) | |
| download | cachepc-linux-dfbc1534eac550b37df592a8a0b550cd47539d0b.tar.gz cachepc-linux-dfbc1534eac550b37df592a8a0b550cd47539d0b.zip | |
Merge branch 'debugfs_automount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs into trace/ftrace/tracefs
Pull in Al Viro's changes to debugfs that implement the new primitive:
debugfs_create_automount(), that creates a directory in debugfs that will
safely mount another file system automatically when debugfs is mounted.
This will let tracefs automount itself on top of debugfs/tracing directory.
Diffstat (limited to 'kernel/exit.c')
| -rw-r--r-- | kernel/exit.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 1ea4369890a3..6806c55475ee 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1287,9 +1287,15 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p) static int wait_consider_task(struct wait_opts *wo, int ptrace, struct task_struct *p) { + /* + * We can race with wait_task_zombie() from another thread. + * Ensure that EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE transition + * can't confuse the checks below. + */ + int exit_state = ACCESS_ONCE(p->exit_state); int ret; - if (unlikely(p->exit_state == EXIT_DEAD)) + if (unlikely(exit_state == EXIT_DEAD)) return 0; ret = eligible_child(wo, p); @@ -1310,7 +1316,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace, return 0; } - if (unlikely(p->exit_state == EXIT_TRACE)) { + if (unlikely(exit_state == EXIT_TRACE)) { /* * ptrace == 0 means we are the natural parent. In this case * we should clear notask_error, debugger will notify us. @@ -1337,7 +1343,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace, } /* slay zombie? */ - if (p->exit_state == EXIT_ZOMBIE) { + if (exit_state == EXIT_ZOMBIE) { /* we don't reap group leaders with subthreads */ if (!delay_group_leader(p)) { /* |