pstore: Improve register_pstore() error reporting

Uncommon errors are better to get reported to dmesg so developers can
more easily figure out why pstore is unhappy with a backend attempting
to register.

Signed-off-by: Kees Cook <keescook@chromium.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index d69ef8a840b9..320a673ecb5b 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -673,11 +673,15 @@ int pstore_register(struct pstore_info *psi)
 {
         struct module *owner = psi->owner;
 
-        if (backend && strcmp(backend, psi->name))
+        if (backend && strcmp(backend, psi->name)) {
+                pr_warn("ignoring unexpected backend '%s'\n", psi->name);
                 return -EPERM;
+        }
 
         spin_lock(&pstore_lock);
         if (psinfo) {
+                pr_warn("backend '%s' already loaded: ignoring '%s'\n",
+                        psinfo->name, psi->name);
                 spin_unlock(&pstore_lock);
                 return -EBUSY;
         }