[PATCH v7 02/18] pstore/platform: Switch pstore_info::name to const

[Kees Cook <keescook@chromium.org>]

In order to more cleanly pass around backend names, make the "name" member
const. This means the module param needs to be dynamic (technically, it
was before, so this actually cleans up a minor memory leak if a backend
was specified and then gets unloaded.)

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 fs/pstore/platform.c   | 3 ++-
 include/linux/pstore.h | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index b882919b8784..e7bf22f01928 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -626,7 +626,7 @@ int pstore_register(struct pstore_info *psi)
 	 * Update the module parameter backend, so it is visible
 	 * through /sys/module/pstore/parameters/backend
 	 */
-	backend = psi->name;
+	backend = kstrdup(psi->name, GFP_KERNEL);
 
 	pr_info("Registered %s as persistent store backend\n", psi->name);
 
@@ -669,6 +669,7 @@ void pstore_unregister(struct pstore_info *psi)
 	free_buf_for_compression();
 
 	psinfo = NULL;
+	kfree(backend);
 	backend = NULL;
 	mutex_unlock(&psinfo_lock);
 }
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index 16a1fdafc167..eb93a54cff31 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -176,7 +176,7 @@ struct pstore_record {
  */
 struct pstore_info {
 	struct module	*owner;
-	char		*name;
+	const char	*name;
 
 	struct semaphore buf_lock;
 	char		*buf;
-- 
2.20.1