| Message ID | 20171018203230.29871-2-k.opasiak@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Oct 18, 2017 at 10:32:27PM +0200, Krzysztof Opasiak wrote: > Allow to get() and put() signal struct from different > parts of kernel core, not only from signal.c. That says what this does, but not _why_. Who would ever want to have access to these internal-only functions? thanks, greg k-h
On 10/19/2017 09:34 AM, Greg KH wrote: > On Wed, Oct 18, 2017 at 10:32:27PM +0200, Krzysztof Opasiak wrote: >> Allow to get() and put() signal struct from different >> parts of kernel core, not only from signal.c. > > That says what this does, but not _why_. Who would ever want to have > access to these internal-only functions? > Those functions are exposed because I added rlimit-events context to the signal_struct and because I'm accessing signal struct of subject (process that's being monitored) from context of monitor I need to ensure that this structure won't go away until I release all watchers that were associated with that process. Best regards,
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) {
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@samsung.com> --- include/linux/sched/signal.h | 13 +++++++++++++ kernel/fork.c | 9 ++------- 2 files changed, 15 insertions(+), 7 deletions(-)