Re: [PATCH 2/2] Simplify (and warn about) right shifts that result in zero

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On Thu, 24 Apr 2008, Pavel Roskin wrote:
> 
> So I would suggest a similar warning is this case.  Maybe "right shift
> too big (%u) for source type %s" (if the source type is readily
> available) or "right shift count (%d) >= width of type (%d)"

That's fine, except we shouldn't talk about "type", since we're really 
doing some really stupid value analysis (the *type* will generally have 
been cast to a bigger one by the implicit C type evaluation rules).

> By the way, your patch has caught something interesting in
> net/mac80211/tkip.c:
> 
>         iv32 = data[hdr_len + 4] +
>                 (data[hdr_len + 5] >> 8) +
>                 (data[hdr_len + 6] >> 16) +
>                 (data[hdr_len + 7] >> 24);
>
> Wow!

Heh. That does look like somebody is shifting the wrong way, and 
apparently the new warning was worth something ;)

		Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-sparse" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Newbies FAQ]     [LKML]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]     [Trinity Fuzzer Tool]

  Powered by Linux