openwrt/target/linux/generic/hack-5.15/420-mtd-set-rootfs-to-be-root-dev.patch
Rafał Miłecki a5265497a4 kernel: fix possible mtd NULL pointer dereference
Fixes: 1a9ee36734 ("kernel: backport mtd dynamic partition patch")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
2022-10-04 12:06:03 +02:00

40 lines
1.1 KiB
Diff

From: Gabor Juhos <juhosg@openwrt.org>
Subject: kernel/3.1[02]: move MTD root device setup code to mtdcore
The current code only allows to automatically set
root device on MTD partitions. Move the code to MTD
core to allow to use it with all MTD devices.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
---
drivers/mtd/mtdcore.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -27,6 +27,7 @@
#include <linux/reboot.h>
#include <linux/leds.h>
#include <linux/debugfs.h>
+#include <linux/root_dev.h>
#include <linux/nvmem-provider.h>
#include <linux/mtd/mtd.h>
@@ -770,6 +771,16 @@ int add_mtd_device(struct mtd_info *mtd)
of this try_ nonsense, and no bitching about it
either. :) */
__module_get(THIS_MODULE);
+
+ if (!strcmp(mtd->name, "rootfs") &&
+ IS_ENABLED(CONFIG_MTD_ROOTFS_ROOT_DEV) &&
+ ROOT_DEV == 0) {
+ unsigned int index = mtd->index;
+ pr_notice("mtd: device %d (%s) set to be root filesystem\n",
+ mtd->index, mtd->name);
+ ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, index);
+ }
+
return 0;
fail_nvmem_add: