[PATCH 02/15] kernel: convert signal_struct.sigcnt from atomic_t to refcount_t

Elena Reshetova
2017-07-07T09:04:16Z

Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
---
include/linux/sched/signal.h | 2 +-
kernel/fork.c | 6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index 4d5cdf1..c5f1a67 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -77,7 +77,7 @@ struct thread_group_cputimer {
* the locking of signal_struct.
*/
struct signal_struct {
- atomic_t sigcnt;
+ refcount_t sigcnt;
atomic_t live;
int nr_threads;
struct list_head thread_head;
diff --git a/kernel/fork.c b/kernel/fork.c
index 4e28f50..a9763f6 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -399,7 +399,7 @@ static inline void free_signal_struct(struct signal_struct *sig)

static inline void put_signal_struct(struct signal_struct *sig)
{
- if (atomic_dec_and_test(&sig->sigcnt))
+ if (refcount_dec_and_test(&sig->sigcnt))
free_signal_struct(sig);
}

@@ -1379,7 +1379,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)

sig->nr_threads = 1;
atomic_set(&sig->live, 1);
- atomic_set(&sig->sigcnt, 1);
+ refcount_set(&sig->sigcnt, 1);

/* list_add(thread_node, thread_head) without INIT_LIST_HEAD() */
sig->thread_head = (struct list_head)LIST_HEAD_INIT(tsk->thread_node);
@@ -1888,7 +1888,7 @@ static __latent_entropy struct task_struct *copy_process(
} else {
current->signal->nr_threads++;
atomic_inc(&current->signal->live);
- atomic_inc(&current->signal->sigcnt);
+ refcount_inc(&current->signal->sigcnt);
list_add_tail_rcu(&p->thread_group,
&p->group_leader->thread_group);
list_add_tail_rcu(&p->thread_node,
--
2.7.4