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-rw-r--r--include/linux/sched.h2
-rw-r--r--kernel/exit.c3
-rw-r--r--kernel/fork.c23
3 files changed, 17 insertions, 11 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index a95a2455cebe..32e309df408c 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -527,6 +527,7 @@ struct thread_group_cputimer {
* the locking of signal_struct.
*/
struct signal_struct {
+ atomic_t sigcnt;
atomic_t count;
atomic_t live;
@@ -2101,7 +2102,6 @@ extern void flush_thread(void);
extern void exit_thread(void);
extern void exit_files(struct task_struct *);
-extern void __cleanup_signal(struct signal_struct *);
extern void __cleanup_sighand(struct sighand_struct *);
extern void exit_itimers(struct signal_struct *);
diff --git a/kernel/exit.c b/kernel/exit.c
index 4a72f1753edb..92af5cde9bbe 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -134,8 +134,6 @@ static void __exit_signal(struct task_struct *tsk)
* doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
*/
flush_sigqueue(&tsk->pending);
-
- tsk->signal = NULL;
tsk->sighand = NULL;
spin_unlock(&sighand->siglock);
@@ -150,7 +148,6 @@ static void __exit_signal(struct task_struct *tsk)
*/
task_rq_unlock_wait(tsk);
tty_kref_put(sig->tty);
- __cleanup_signal(sig);
}
}
diff --git a/kernel/fork.c b/kernel/fork.c
index b7879ef6e7cd..e08e3012cd6b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -165,6 +165,18 @@ void free_task(struct task_struct *tsk)
}
EXPORT_SYMBOL(free_task);
+static inline void free_signal_struct(struct signal_struct *sig)
+{
+ thread_group_cputime_free(sig);
+ kmem_cache_free(signal_cachep, sig);
+}
+
+static inline void put_signal_struct(struct signal_struct *sig)
+{
+ if (atomic_dec_and_test(&sig->sigcnt))
+ free_signal_struct(sig);
+}
+
void __put_task_struct(struct task_struct *tsk)
{
WARN_ON(!tsk->exit_state);
@@ -173,6 +185,7 @@ void __put_task_struct(struct task_struct *tsk)
exit_creds(tsk);
delayacct_tsk_free(tsk);
+ put_signal_struct(tsk->signal);
if (!profile_handoff_task(tsk))
free_task(tsk);
@@ -864,6 +877,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
if (!sig)
return -ENOMEM;
+ atomic_set(&sig->sigcnt, 1);
atomic_set(&sig->count, 1);
atomic_set(&sig->live, 1);
init_waitqueue_head(&sig->wait_chldexit);
@@ -889,12 +903,6 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
return 0;
}
-void __cleanup_signal(struct signal_struct *sig)
-{
- thread_group_cputime_free(sig);
- kmem_cache_free(signal_cachep, sig);
-}
-
static void copy_flags(unsigned long clone_flags, struct task_struct *p)
{
unsigned long new_flags = p->flags;
@@ -1248,6 +1256,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
}
if (clone_flags & CLONE_THREAD) {
+ atomic_inc(&current->signal->sigcnt);
atomic_inc(&current->signal->count);
atomic_inc(&current->signal->live);
p->group_leader = current->group_leader;
@@ -1294,7 +1303,7 @@ bad_fork_cleanup_mm:
mmput(p->mm);
bad_fork_cleanup_signal:
if (!(clone_flags & CLONE_THREAD))
- __cleanup_signal(p->signal);
+ free_signal_struct(p->signal);
bad_fork_cleanup_sighand:
__cleanup_sighand(p->sighand);
bad_fork_cleanup_fs: