linux-kernel - [PATCH 01/10] pstore: Drop useless try_module

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Message-Id: <20200506152114.50375-2-keescook@chromium.org>
Date:   Wed,  6 May 2020 08:21:05 -0700
From:   Kees Cook <keescook@...omium.org>
To:     linux-kernel@...r.kernel.org
Cc:     Kees Cook <keescook@...omium.org>,
        Anton Vorontsov <anton@...msg.org>,
        Colin Cross <ccross@...roid.com>,
        Tony Luck <tony.luck@...el.com>,
        Luis Henriques <lhenriques@...e.com>
Subject: [PATCH 01/10] 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.

Signed-off-by: Kees Cook <keescook@...omium.org>
---
 fs/pstore/platform.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 408277ee3cdb..44f8b9742263 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -555,8 +555,6 @@ static int pstore_write_user_compat(struct pstore_record *record,
  */
 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);
-- 
2.20.1