Re: Sparse errors

[Dan Carpenter <dan.carpenter@oracle.com>]

On Tue, May 25, 2021 at 02:32:27PM -0500, Pierre-Louis Bossart wrote:
> Hi Takashi,
> Sparse reports a lot of new issues in our last checks with more options:
> 
> export ARCH=x86_64 CF="-Wsparse-error -Wsparse-all -Wno-bitwise-pointer
> -Wno-pointer-arith -Wno-typesign -Wnoshadow -Wno-sizeof-bool"
> make -k sound/ C=2
> 
> most are linked to the __user and pcm_format_t restricted types, but I found
> the simpler ones below which are useless comparisons. I can send a patch for
> the last but not sure how to address the first two.
> 
> Thanks for your feedback
> -Pierre
> 
> sound/core/info.c:95:38: error: self-comparison always evaluates to false
> 
> 	if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
> 		return false;
> 
> not sure what the second comparison is meant to check?

It's checking for if a 32 bit system is using the upper 32 bits of a
u64.

This one is valid, the rest are nonsense code.

regards,
dan carpenter