[U-Boot] [PATCH] Prevent malloc with size 0

Joakim Tjernlund joakim.tjernlund at transmode.se
Fri Oct 22 18:40:07 CEST 2010


Mike Frysinger <vapier at gentoo.org> wrote on 2010/10/22 17:18:05:
>
> On Friday, October 22, 2010 04:34:52 Joakim Tjernlund wrote:
> > Don't you want to know if the app screwed up or if the system is out
> > of memory?
> >
> > The only upside to malloc(0) == NULL I can see is an extra check
> > for apps for which size == 0 is an error to the app too(something the app
> > should have checked itself long before calling malloc).
>
> if an app is doing malloc(0), it is broken.  i'm really not worried at all

In your opinion, not mine and not POSIX either. I outlined uses for malloc(0) earlier.

> about detecting OOM state.  my real world experience thus far has shown no
> actual problems with this behavior.  so unless you have some actual examples
> where this behavior "harms" u-boot, i say we merge the OP's patch.

Since you think an app is broken if it does malloc(0), it should not matter
what malloc(0) returns to you. You only gain an extra error check for the broken app
at the expense of ease of use and sane error checking in general.
I prefer not to make it easier for broken apps when it hurts elsewhere.

>
> > hmm, "destroys quoted context", I think that is a new one. What
> > exactly is destroyed?
>
> it seems it fails to rewrap quoted lines and then when other people reply,
> their clients arent able to recover thus screwing it up even more.  pick any
> msg from you in this thread.  like this one:
>    http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/87174/focus=87290

Ah, IT changed some settings globally. I changed it back. I hope this reply
is better.



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