lkml.org 
[lkml]   [2007]   [Aug]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: kfree(0) - ok?

On Aug 15 2007 09:58, Kyle Moffett wrote:
>
> Irrespective of whatever the standard says, EVERY platform and
> compiler anybody makes nowadays has a NULL pointer value with all
> bits clear. Theoretically the standard allows otherwise, but such
> a decision would break so much code. Linux especially, we rely on
> the uninitialized data to have all bits clear and we depend on that
> producing NULL pointers; if a NULL pointer was not bitwise exactly
> 0 then the test "if (some_ptr != NULL)" would fail and we would
> start dereferencing garbage.

But if kmalloc returns NULL on failure, then testing for NULL
(irrespective of being 0 or 0xDEADBEEF) is ok.
What would actually concern me then is what "if (!some_ptr)" would do.
Probably not the right thing.

Jan
--
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-08-15 16:09    [from the cache]
©2003-2011 Jasper Spaans