Hi Christoph,
On Fri, Jun 14, 2019 at 9:18 AM Christoph Hellwig <hch@xxxxxx> wrote:
> On Thu, Jun 13, 2019 at 10:35:44PM +0200, Geert Uytterhoeven wrote:
> > I'm always triggered by the use of min_t() and other casts:
> > mmc->max_blk_size and mmc->max_blk_count are both unsigned int.
> > dma_max_mapping_size() returns size_t, which can be 64-bit.
> >
> > 1) Can the multiplication overflow?
> > Probably not, as per commit 2a55c1eac7882232 ("mmc: renesas_sdhi:
> > prevent overflow for max_req_size"), but I thought I'd better ask.
> > 2) In theory, dma_max_mapping_size() can return a number that doesn't
> > fit in 32-bit, and will be truncated (to e.g. 0), leading to max_req_size
> > is zero?
>
> This really should use a min_t on size_t. Otherwise the patch looks
> fine:
Followed by another min() to make it fit in mmc->max_req_size, which is
unsigned int.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
