[lkml]   [2006]   [Nov]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] Don't compare unsigned variable for <0 in sys_prctl()
On 28/11/06, Linus Torvalds <> wrote:
> On Tue, 28 Nov 2006, Jesper Juhl wrote:
> >
> > In kernel/sys.c::sys_prctl() the argument named 'arg2' is very clearly
> > of type 'unsigned long', and when compiling with "gcc -W" gcc also warns :
> > kernel/sys.c:2089: warning: comparison of unsigned expression < 0 is always false
> >
> > So this patch removes the test of "arg2 < 0".
> No, we don't do this.
> This is why we don't compile with "-W". Gcc is crap.
> The fact is, if it's unsigned, it's not something that the programmer
> should have to care about. We should write our code to be readable and
> obviously safe, and that means that
> if (x < 0 || x > MAX)
> return -ERROR;
> is the _right_ way to do things, without having to carry stupid context
> around in our heads.
> If the compiler (whose _job_ it is to carry all that context and use it to
> generate good code) notices that the fact that "x" is unsignes means that
> one of the tests is unnecessary, that does not make it wrong.
> Gcc warns for a lot of wrong things. This is one of them.
> Friends don't let friends use "-W".
Hehe, ok, I'll stop cleaning this stuff up then.
Nice little hobby out the window there ;)

Jesper Juhl <>
Don't top-post
Plain text mails only, please
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2006-11-28 23:37    [W:0.051 / U:0.468 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site