From: Chris Packham <chris.packham@alliedtelesis.co.nz>
Date: Fri, 27 Nov 2020 00:07:08 +0000 (+1300)
Subject: libmtd: avoid divide by zero
X-Git-Tag: v2.1.3~10
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=54d68799;p=mtd-utils.git

libmtd: avoid divide by zero

The concept of erase blocks doesn't apply to mtd-ram devices. Such
devices set MTD_NO_ERASE to indicate this and some report 0 for the
erase block size. Avoid a divide by zero when calculating the erase
block count for such devices.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
---

diff --git a/lib/libmtd.c b/lib/libmtd.c
index 9d8d0e8..b581d80 100644
--- a/lib/libmtd.c
+++ b/lib/libmtd.c
@@ -791,7 +791,10 @@ int mtd_get_dev_info1(libmtd_t desc, int mtd_num, struct mtd_dev_info *mtd)
 		return -1;
 	mtd->writable = !!(ret & MTD_WRITEABLE);
 
-	mtd->eb_cnt = mtd->size / mtd->eb_size;
+	if (ret & MTD_NO_ERASE)
+		mtd->eb_cnt = 1;
+	else
+		mtd->eb_cnt = mtd->size / mtd->eb_size;
 	mtd->type = type_str2int(mtd->type_str);
 	mtd->bb_allowed = !!(mtd->type == MTD_NANDFLASH ||
 				mtd->type == MTD_MLCNANDFLASH);