Hi Christoph,

On Fri, Jun 14, 2019 at 9:18 AM Christoph Hellwig <h...@lst.de> 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 -- ge...@linux-m68k.org

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
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