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| author |   Vinit Agnihotri <vinit.agnihotri@gmail.com> | 2007-07-10 13:04:59 +0300 |
|---|---|---|
| committer |   Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2007-07-18 16:58:12 +0300 |
| commit | d08c3b78b8c46a01b8fa59037a0d9fbb777fb465 (patch) | |
| tree | c27d7d436864175107fe8e2b1de3a11b928c975a /drivers/mtd | |
| parent | UBI: bugfix in max_sqnum calculation (diff) | |
| download | linux-dev-d08c3b78b8c46a01b8fa59037a0d9fbb777fb465.tar.xz linux-dev-d08c3b78b8c46a01b8fa59037a0d9fbb777fb465.zip | |
UBI: fix overflow bug
I was experiencing overflows in multiplications for
volume->used_bytes in vmt.c & vtbl.c, while creating & resizing large volumes.
vol->used_bytes is long long however its 2 operands vol->used_ebs &
vol->usable_leb_size
are int. So their multiplication for larger values causes integer overflows.
Typecasting them solves the problem.
My machine & flash details:
64Bit dual-core AMD opteron, 1 GB RAM, linux 2.6.18.3.
mtd size = 6GB, volume size= 5GB, peb_size = 4MB.
heres patch which does the fix.
Signed-off-by: Vinit Agnihotri <vinit.agnihotri@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'drivers/mtd')
| -rw-r--r-- | drivers/mtd/ubi/vmt.c | 8 | ||||
| -rw-r--r-- | drivers/mtd/ubi/vtbl.c | 9 |
2 files changed, 11 insertions, 6 deletions
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c index d62dac90e108..ea0d5c825ab4 100644 --- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c @@ -280,7 +280,8 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req) if (vol->vol_type == UBI_DYNAMIC_VOLUME) { vol->used_ebs = vol->reserved_pebs; vol->last_eb_bytes = vol->usable_leb_size; - vol->used_bytes = vol->used_ebs * vol->usable_leb_size; + vol->used_bytes = + (long long)vol->used_ebs * vol->usable_leb_size; } else { bytes = vol->used_bytes; vol->last_eb_bytes = do_div(bytes, vol->usable_leb_size); @@ -538,7 +539,8 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs) if (vol->vol_type == UBI_DYNAMIC_VOLUME) { vol->used_ebs = reserved_pebs; vol->last_eb_bytes = vol->usable_leb_size; - vol->used_bytes = vol->used_ebs * vol->usable_leb_size; + vol->used_bytes = + (long long)vol->used_ebs * vol->usable_leb_size; } paranoid_check_volumes(ubi); @@ -739,7 +741,7 @@ static void paranoid_check_volume(struct ubi_device *ubi, int vol_id) goto fail; } - n = vol->used_ebs * vol->usable_leb_size; + n = (long long)vol->used_ebs * vol->usable_leb_size; if (vol->vol_type == UBI_DYNAMIC_VOLUME) { if (vol->corrupted != 0) { ubi_err("corrupted dynamic volume"); diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c index 1f48c76cf6fe..bc5df50813d6 100644 --- a/drivers/mtd/ubi/vtbl.c +++ b/drivers/mtd/ubi/vtbl.c @@ -531,7 +531,8 @@ static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si, if (vol->vol_type == UBI_DYNAMIC_VOLUME) { vol->used_ebs = vol->reserved_pebs; vol->last_eb_bytes = vol->usable_leb_size; - vol->used_bytes = vol->used_ebs * vol->usable_leb_size; + vol->used_bytes = + (long long)vol->used_ebs * vol->usable_leb_size; continue; } @@ -561,7 +562,8 @@ static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si, } vol->used_ebs = sv->used_ebs; - vol->used_bytes = (vol->used_ebs - 1) * vol->usable_leb_size; + vol->used_bytes = + (long long)(vol->used_ebs - 1) * vol->usable_leb_size; vol->used_bytes += sv->last_data_size; vol->last_eb_bytes = sv->last_data_size; } @@ -578,7 +580,8 @@ static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si, vol->usable_leb_size = ubi->leb_size; vol->used_ebs = vol->reserved_pebs; vol->last_eb_bytes = vol->reserved_pebs; - vol->used_bytes = vol->used_ebs * (ubi->leb_size - vol->data_pad); + vol->used_bytes = + (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad); vol->vol_id = UBI_LAYOUT_VOL_ID; ubi_assert(!ubi->volumes[i]); |