1 files changed, 51 insertions, 4 deletions

diff --git a/kernel/fs/pstore/platform.c b/kernel/fs/pstore/platform.c
index c4c9a10c5..588461bb2 100644
--- a/kernel/fs/pstore/platform.c
+++ b/kernel/fs/pstore/platform.c
@@ -237,6 +237,14 @@ static void allocate_buf_for_compression(void)
 
 }
 
+static void free_buf_for_compression(void)
+{
+	kfree(stream.workspace);
+	stream.workspace = NULL;
+	kfree(big_oops_buf);
+	big_oops_buf = NULL;
+}
+
 /*
  * Called when compression fails, since the printk buffer
  * would be fetched for compression calling it again when
@@ -299,7 +307,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
 		bool compressed;
 		size_t total_len;
 
-		if (big_oops_buf) {
+		if (big_oops_buf && is_locked) {
 			dst = big_oops_buf;
 			hsize = sprintf(dst, "%s#%d Part%u\n", why,
 							oopscount, part);
@@ -353,6 +361,19 @@ static struct kmsg_dumper pstore_dumper = {
 	.dump = pstore_dump,
 };
 
+/*
+ * Register with kmsg_dump to save last part of console log on panic.
+ */
+static void pstore_register_kmsg(void)
+{
+	kmsg_dump_register(&pstore_dumper);
+}
+
+static void pstore_unregister_kmsg(void)
+{
+	kmsg_dump_unregister(&pstore_dumper);
+}
+
 #ifdef CONFIG_PSTORE_CONSOLE
 static void pstore_console_write(struct console *con, const char *s, unsigned c)
 {
@@ -390,8 +411,14 @@ static void pstore_register_console(void)
 {
 	register_console(&pstore_console);
 }
+
+static void pstore_unregister_console(void)
+{
+	unregister_console(&pstore_console);
+}
 #else
 static void pstore_register_console(void) {}
+static void pstore_unregister_console(void) {}
 #endif
 
 static int pstore_write_compat(enum pstore_type_id type,
@@ -410,8 +437,6 @@ static int pstore_write_compat(enum pstore_type_id type,
  * read function right away to populate the file system. If not
  * then the pstore mount code will call us later to fill out
  * the file system.
- *
- * Register with kmsg_dump to save last part of console log on panic.
  */
 int pstore_register(struct pstore_info *psi)
 {
@@ -442,7 +467,7 @@ int pstore_register(struct pstore_info *psi)
 	if (pstore_is_mounted())
 		pstore_get_records(0);
 
-	kmsg_dump_register(&pstore_dumper);
+	pstore_register_kmsg();
 
 	if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) {
 		pstore_register_console();
@@ -456,12 +481,34 @@ int pstore_register(struct pstore_info *psi)
 		add_timer(&pstore_timer);
 	}
 
+	/*
+	 * Update the module parameter backend, so it is visible
+	 * through /sys/module/pstore/parameters/backend
+	 */
+	backend = psi->name;
+
+	module_put(owner);
+
 	pr_info("Registered %s as persistent store backend\n", psi->name);
 
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pstore_register);
 
+void pstore_unregister(struct pstore_info *psi)
+{
+	pstore_unregister_pmsg();
+	pstore_unregister_ftrace();
+	pstore_unregister_console();
+	pstore_unregister_kmsg();
+
+	free_buf_for_compression();
+
+	psinfo = NULL;
+	backend = NULL;
+}
+EXPORT_SYMBOL_GPL(pstore_unregister);
+
 /*
  * Read all the records from the persistent store. Create
  * files in our filesystem.  Don't warn about -EEXIST errors