[PATCH] mtd: fix 'part' field data corruption in mtd_info

Oleksandr Ocheretnyi oocheret at cisco.com
Sun Apr 17 11:46:47 PDT 2022


Commit 46b5889cc2c5 ("mtd: implement proper partition handling")
started using "mtd_get_master_ofs()" in mtd callbacks to determine
memory offsets by means of 'part' field from mtd_info, what previously
was smashed accessing 'master' field in the mtd_set_dev_defaults() method.
That provides wrong offset what causes hardware access errors.

Just make 'part', 'master' as separate fields, rather than using
union type to avoid 'part' data corruption when mtd_set_dev_defaults()
is called.

Fixes: 46b5889cc2c5 ("mtd: implement proper partition handling")
Signed-off-by: Oleksandr Ocheretnyi <oocheret at cisco.com>
---
 include/linux/mtd/mtd.h | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 88227044fc86..8a2c60235ebb 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -394,10 +394,8 @@ struct mtd_info {
 	/* List of partitions attached to this MTD device */
 	struct list_head partitions;
 
-	union {
-		struct mtd_part part;
-		struct mtd_master master;
-	};
+	struct mtd_part part;
+	struct mtd_master master;
 };
 
 static inline struct mtd_info *mtd_get_master(struct mtd_info *mtd)
-- 
2.26.2.Cisco




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