Messages in this thread | | | Date | Mon, 28 Sep 2015 17:28:55 -0700 | From | Brian Norris <> | Subject | Re: [PATCH v2] mtd: blktrans: fix multiplication overflow |
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On Fri, Sep 11, 2015 at 09:41:47PM +0800, Peng Fan wrote: > In drivers/mtd/mtd_blkdevs.c: > 406 set_capacity(gd, (new->size * tr->blksize) >> 9); > The type of new->size is unsigned long and the type of tr->blksize is int, > the result of 'new->size * tr->blksize' may exceed ULONG_MAX on 32bit > machines. > > I use nand chip MT29F32G08CBADBWP which is 4GB and the parameters passed > to kernel is 'mtdparts=gpmi-nand:-(user)', the whole nand chip will be > treated as a 4GB mtd partition. new->size is 0x800000 and tr->blksize is > 0x200, 'new->size * tr->blksize' however is 0. This is what we do not want > to see. > > Using type cast u64 to fix the multiplication overflow issue. > > Signed-off-by: Peng Fan <van.freenix@gmail.com> > Cc: David Woodhouse <dwmw2@infradead.org> > Cc: Brian Norris <computersforpeace@gmail.com> > --- > > Changes V2: > use type cast to avoid build break for platforms which does not support 64 bit multilplication.
Thanks, pushed to l2-mtd.git
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