pstore/ram: Set pstore flags dynamically

The ramoops can be configured to enable each pstore type by setting
their size.  In that case, it'd be better not to register disabled types
in the first place.

Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

fs/pstore/ram.c

@@ -623,7 +623,13 @@ static int ramoops_probe(struct platform_device *pdev)
 		goto fail_clear;
 	}
 
-	cxt->pstore.flags = PSTORE_FLAGS_ALL;
+	cxt->pstore.flags = PSTORE_FLAGS_DMESG;
+	if (cxt->console_size)
+		cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
+	if (cxt->ftrace_size)
+		cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
+	if (cxt->pmsg_size)
+		cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
 
 	err = pstore_register(&cxt->pstore);
 	if (err) {

include/linux/pstore.h

@@ -80,8 +80,6 @@ struct pstore_info {
 #define PSTORE_FLAGS_FTRACE	(1 << 2)
 #define PSTORE_FLAGS_PMSG	(1 << 3)
 
-#define PSTORE_FLAGS_ALL	((1 << 4) - 1)
-
 extern int pstore_register(struct pstore_info *);
 extern void pstore_unregister(struct pstore_info *);
 extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason);