[PATCH 1/4][PoC][RFC] sched: Allow to get() and put() signal struct

From: Krzysztof Opasiak
Date: Wed Oct 18 2017 - 16:33:39 EST


Allow to get() and put() signal struct from different
parts of kernel core, not only from signal.c.

Signed-off-by: Krzysztof Opasiak <k.opasiak@xxxxxxxxxxx>
---
include/linux/sched/signal.h | 13 +++++++++++++
kernel/fork.c | 9 ++-------
2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index c06d63b3a583..05cef037fbf2 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -609,4 +609,17 @@ static inline unsigned long rlimit_max(unsigned int limit)
return task_rlimit_max(current, limit);
}

+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))
+ free_signal_struct(sig);
+}
+
+static inline void get_signal_struct(struct signal_struct *sig)
+{
+ atomic_inc(&sig->sigcnt);
+}
+
#endif /* _LINUX_SCHED_SIGNAL_H */
diff --git a/kernel/fork.c b/kernel/fork.c
index e53770d2bf95..a98336d154b6 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -390,7 +390,7 @@ void free_task(struct task_struct *tsk)
}
EXPORT_SYMBOL(free_task);

-static inline void free_signal_struct(struct signal_struct *sig)
+void free_signal_struct(struct signal_struct *sig)
{
taskstats_tgid_free(sig);
sched_autogroup_exit(sig);
@@ -402,12 +402,7 @@ static inline void free_signal_struct(struct signal_struct *sig)
mmdrop_async(sig->oom_mm);
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);
-}
+EXPORT_SYMBOL_GPL(free_signal_struct);

void __put_task_struct(struct task_struct *tsk)
{
--
2.9.3