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authorEnrico Jorns <ejo@pengutronix.de>2022-08-19 14:32:13 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2022-09-27 08:32:46 +0200
commitb83c64f7a12538417649accc1269c22d5ff074bb (patch)
tree04afb5e431fa023daf201438cf4e5a1d36aa6700 /lib
parent374d3cd10eebacae3f5e987ce9e8cf8e8418a4db (diff)
libmtd: do not ignore non-zero eraseblock size when MTD_NO_ERASE is set
In 54d68799, mtd->eb_cnt was enforced to be '1' if MTD_NO_ERASE is set. This was done with the aim of preventing divisions by zero. However, even if MTD_NO_ERASE is set, mtd->eb_size (eraseblock size) can still be set to a non-zero value which would not cause a division by zero. Instead, enforcing an eraseblock count of '1' here even leads to inconsistent eraseblock counting in mtd-utils and lets for example a 'flash_erase' on an mtdnand device fail: | # flash_erase /dev/mtd0 0 0 | Erasing 32768 Kibyte @ 0 -- 0 % complete libmtd: error!: bad eraseblock number 255, mtd0 has 1 eraseblocks | flash_erase: error!: /dev/mtd0: MTD Erase entire chip failureTrying one by one each sector. | error 22 (Invalid argument) | Erasing 128 Kibyte @ 0 -- 0 % complete libmtd: error!: bad eraseblock number 1, mtd0 has 1 eraseblocks | flash_erase: error!: /dev/mtd0: MTD get bad block failed | error 22 (Invalid argument) Also mtdinfo would look inconsistent (eraseblock size vs amount): | # mtdinfo /dev/mtd0 | mtd0 | Name: mtdram test device | Type: ram | Eraseblock size: 131072 bytes, 128.0 KiB | Amount of eraseblocks: 1 (33554432 bytes, 32.0 MiB) | Minimum input/output unit size: 1 byte | Sub-page size: 1 byte | Character device major/minor: 90:0 | Bad blocks are allowed: false | Device is writable: true Fix this by enforcing mtd->eb_cnt to be '1' only when mtd->eb_size is actually zero and would lead to a division by zero otherwise. Fixes: 54d68799 ("libmtd: avoid divide by zero") Signed-off-by: Enrico Jorns <ejo@pengutronix.de> Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib')
-rw-r--r--lib/libmtd.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/libmtd.c b/lib/libmtd.c
index a363e56..4aee947 100644
--- a/lib/libmtd.c
+++ b/lib/libmtd.c
@@ -792,7 +792,7 @@ int mtd_get_dev_info1(libmtd_t desc, int mtd_num, struct mtd_dev_info *mtd)
return -1;
mtd->writable = !!(ret & MTD_WRITEABLE);
- if (ret & MTD_NO_ERASE)
+ if ((ret & MTD_NO_ERASE) && (mtd->eb_size == 0))
mtd->eb_cnt = 1;
else
mtd->eb_cnt = mtd->size / mtd->eb_size;