[Mesa-dev] [PATCH 0/2] Simple Klocwork patches

[Matt Turner]

On Sun, Feb 7, 2016 at 1:37 PM, Juha-Pekka Heikkilä
<juhapekka.heikkila at gmail.com> wrote:
> Hi Iago,
>
> I know there are lot of places where there is malloc unchecked still
> -- and then there is ralloc which is a story of its own. Reason why I
> think checking these would be remotely useful in windows only (or
> other way around, not under linux kernel) is on Windows one can get
> the null pointer from malloc. On Androids I think memory over
> committing has always been enabled and on Linux I suspect I belong to
> the minority who like to set ulimits for memory.
>
> I agree checking these mostly is quite useless but there are those
> corners where it may suddenly become valuable. When process is running
> and everything has settled it will be weird if hit any of these checks
> but any code which is run when process is starting I notice is the
> place where things will fail if they fail. This is of course just my
> opinion about the value of these checks but I really dislike
> possibility of segfault when it is coming from a library.
>
> I didn't quickly notice where _mesa_error() get more heap. Stack it of
> course needs but when I did stress test these _mesa_error() did still
> work. Cannot promise my test was 100% correct though, I think it was
> over year ago when I was playing with it.

There's no guarantee that fprintf() doesn't call malloc. In fact, glibc's does.

Adding these checks is really useless.