Re: [PATCH v6 07/10] proc: flush task dcache entries from all procfs instances

From: J Freyensee
Date: Mon Dec 30 2019 - 17:03:41 EST


snip

.

.

.

+#ifdef CONFIG_PROC_FS
+static inline void pidns_proc_lock(struct pid_namespace *pid_ns)
+{
+ down_write(&pid_ns->rw_proc_mounts);
+}
+
+static inline void pidns_proc_unlock(struct pid_namespace *pid_ns)
+{
+ up_write(&pid_ns->rw_proc_mounts);
+}
+
+static inline void pidns_proc_lock_shared(struct pid_namespace *pid_ns)
+{
+ down_read(&pid_ns->rw_proc_mounts);
+}
+
+static inline void pidns_proc_unlock_shared(struct pid_namespace *pid_ns)
+{
+ up_read(&pid_ns->rw_proc_mounts);
+}
+#else /* !CONFIG_PROC_FS */
+
Apologies for my newbie question. I couldn't help but notice all these function calls are assuming that the parameter struct pid_namespace *pid_ns will never be NULL. Is that a good assumption?

I don't have the background in this code to answer on my own, but I thought I'd raise the question.

Thanks,
Jay