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path: root/drivers/mtd/ubi/scan.c
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Diffstat (limited to 'drivers/mtd/ubi/scan.c')
-rw-r--r--drivers/mtd/ubi/scan.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index c3d653ba5ca..b847745394b 100644
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -757,6 +757,8 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
si->is_empty = 0;
if (!ec_corr) {
+ int image_seq;
+
/* Make sure UBI version is OK */
if (ech->version != UBI_VERSION) {
ubi_err("this UBI version is %d, image version is %d",
@@ -778,6 +780,29 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
ubi_dbg_dump_ec_hdr(ech);
return -EINVAL;
}
+
+ /*
+ * Make sure that all PEBs have the same image sequence number.
+ * This allows us to detect situations when users flash UBI
+ * images incorrectly, so that the flash has the new UBI image
+ * and leftovers from the old one. This feature was added
+ * relatively recently, and the sequence number was always
+ * zero, because old UBI implementations always set it to zero.
+ * For this reasons, we do not panic if some PEBs have zero
+ * sequence number, while other PEBs have non-zero sequence
+ * number.
+ */
+ image_seq = be32_to_cpu(ech->image_seq);
+ if (!si->image_seq_set) {
+ ubi->image_seq = image_seq;
+ si->image_seq_set = 1;
+ } else if (ubi->image_seq && ubi->image_seq != image_seq) {
+ ubi_err("bad image sequence number %d in PEB %d, "
+ "expected %d", image_seq, pnum, ubi->image_seq);
+ ubi_dbg_dump_ec_hdr(ech);
+ return -EINVAL;
+ }
+
}
/* OK, we've done with the EC header, let's look at the VID header */