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Diffstat (limited to 'kernel/exit.c')
-rw-r--r--kernel/exit.c19
1 files changed, 14 insertions, 5 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 546774a31a6..ce1e48c2d93 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -85,7 +85,9 @@ static void __exit_signal(struct task_struct *tsk)
BUG_ON(!sig);
BUG_ON(!atomic_read(&sig->count));
- sighand = rcu_dereference(tsk->sighand);
+ sighand = rcu_dereference_check(tsk->sighand,
+ rcu_read_lock_held() ||
+ lockdep_is_held(&tasklist_lock));
spin_lock(&sighand->siglock);
posix_cpu_timers_exit(tsk);
@@ -170,8 +172,10 @@ void release_task(struct task_struct * p)
repeat:
tracehook_prepare_release_task(p);
/* don't need to get the RCU readlock here - the process is dead and
- * can't be modifying its own credentials */
+ * can't be modifying its own credentials. But shut RCU-lockdep up */
+ rcu_read_lock();
atomic_dec(&__task_cred(p)->user->processes);
+ rcu_read_unlock();
proc_flush_task(p);
@@ -473,9 +477,11 @@ static void close_files(struct files_struct * files)
/*
* It is safe to dereference the fd table without RCU or
* ->file_lock because this is the last reference to the
- * files structure.
+ * files structure. But use RCU to shut RCU-lockdep up.
*/
+ rcu_read_lock();
fdt = files_fdtable(files);
+ rcu_read_unlock();
for (;;) {
unsigned long set;
i = j * __NFDBITS;
@@ -521,10 +527,12 @@ void put_files_struct(struct files_struct *files)
* at the end of the RCU grace period. Otherwise,
* you can free files immediately.
*/
+ rcu_read_lock();
fdt = files_fdtable(files);
if (fdt != &files->fdtab)
kmem_cache_free(files_cachep, files);
free_fdtable(fdt);
+ rcu_read_unlock();
}
}
@@ -944,7 +952,8 @@ NORET_TYPE void do_exit(long code)
preempt_count());
acct_update_integrals(tsk);
-
+ /* sync mm's RSS info before statistics gathering */
+ sync_mm_rss(tsk, tsk->mm);
group_dead = atomic_dec_and_test(&tsk->signal->live);
if (group_dead) {
hrtimer_cancel(&tsk->signal->real_timer);
@@ -1180,7 +1189,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
if (unlikely(wo->wo_flags & WNOWAIT)) {
int exit_code = p->exit_code;
- int why, status;
+ int why;
get_task_struct(p);
read_unlock(&tasklist_lock);