Re: [PATCH] fortify: Use WARN instead of BUG for now

[Linus Torvalds]

On Tue, Jul 25, 2017 at 8:50 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> +
> +void fortify_read_overflow(const char *func)
>  {
> -       pr_emerg("detected buffer overflow in %s\n", name);
> -       BUG();
> +       WARN(1, "detected read beyond size of object passed as 1st parameter in %s\n", func);
>  }

Side note: have you actually checked the code generation of this all?

In particular, do you have any reason to use the out-of-line
functions? Our WARN() code isn't horrible, and isn't likely to be
noticeably worse than your own explicit out-of-lining. And you'd get
the "unlikely()" for free, so you'll possibly get smaller code that
runs better too.

And it would even *look* better. This:

        if (p_size < size)
               fortify_read_overflow(__func__);

would become

       WARN(p_size < size, "kmemdup size overflow");

or something.

             Linus