Re: [PATCH] fs/fcntl.c : don't test unsigned value for less than zero
From: Herbert Xu
Date: Fri Apr 15 2005 - 07:06:51 EST
Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>
>> No, it was exactly this patch:
>> http://www.ussg.iu.edu/hypermail/linux/kernel/0401.0/1816.html
>
> Hmm. Looks I absolutely disagree with Linus on this one ;-)
Me too. The compiler doesn't really have much choice here. If
it ignores all comparisons of unsigned integers to less than zero
then we could miss real bugs like this:
int foo(unsigned int val)
{
return val < 0;
}
where the user probably wanted a signed comparison.
I suppose it could be smart and stay quiet about
val < 0 || val > BOUND
However, gcc is slow enough as it is without adding unnecessary
smarts like this.
--
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