pstore: Drop useless try_module_get() for backend

There is no reason to be doing a module get/put in pstore_register(),
since the module calling pstore_register() cannot be unloaded since it
hasn't finished its initialization. Remove it so there is no confusion
about how registration ordering works.

Link: https://lore.kernel.org/lkml/20200506152114.50375-2-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 408277e..44f8b97 100644 (file)
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -555,8 +555,6 @@ out:
  */
 int pstore_register(struct pstore_info *psi)
 {
-       struct module *owner = psi->owner;
-
        if (backend && strcmp(backend, psi->name)) {
                pr_warn("ignoring unexpected backend '%s'\n", psi->name);
                return -EPERM;
@@ -591,10 +589,6 @@ int pstore_register(struct pstore_info *psi)
        sema_init(&psinfo->buf_lock, 1);
        spin_unlock(&pstore_lock);
 
-       if (owner && !try_module_get(owner)) {
-               psinfo = NULL;
-               return -EINVAL;
-       }
 
        if (psi->flags & PSTORE_FLAGS_DMESG)
                allocate_buf_for_compression();
@@ -626,8 +620,6 @@ int pstore_register(struct pstore_info *psi)
 
        pr_info("Registered %s as persistent store backend\n", psi->name);
 
-       module_put(owner);
-
        return 0;
 }
 EXPORT_SYMBOL_GPL(pstore_register);