Re: Patch for cppcheck error "Common realloc mistake"

[Julien Nabet <serval2412 yahoo fr>]

Le 27/10/2011 18:27, Mukund Sivaraman a écrit :
> Hi Julien
>
> On Thu, Oct 27, 2011 at 05:48:23PM +0200, Julien wrote:
> > Hello,
> >
> > I had sent a simple proposed patch 21/08 (http://old.nabble.com/Patch-for-cppcheck-error-%22Common-realloc-mistake%22-to32305733.html)
> [snip]
> >                   if (address_string_len<  len + 3) {
> >                           address_string_len = len + 3;
> > -                        address_string = (char *) g_try_realloc
> > (address_string, address_string_len);
> > +                        address_string = (char *) g_realloc
> > (address_string, address_string_len);
> >                   }
> >
> >                   memcpy (address_string, "0x", 2);
> If address_string is NULL as returned by g_try_realloc(), the following
> memcpy() would cause the process to segfault, perhaps creating a core.
>
> With your patch, it abort()s _if_ the underlying realloc() returns
> NULL.  But you better read Documentation/vm/overcommit-accounting in a
> Linux kernel tree.  Similar implementations exist in other demand
> paging kernels too.
>
> There have also been many discussions on whether to check the return
> value of a NULL-returning malloc() at all.  See this as an example:
> http://news.ycombinator.com/item?id=3112309
Thank you Mukund for these information. I'll take a look at the links 
you gave
> 		Mukund
Julien