Re: v4.10: kernel stack frame pointer .. has bad value (null)

From: Andy Lutomirski
Date: Wed Mar 08 2017 - 14:04:21 EST


On Wed, Mar 8, 2017 at 10:25 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, Mar 8, 2017 at 9:37 AM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
> Yeah. At some point we might even upgrade the compiler requirements to
> no longer accept the mcount model.
>
> I think the fentry model is gcc-4.6.0 and up. Currently I guess we
> support gcc-3.2+, which is fairly ridiculous considering that 4.6.0 is
> from March, 2011. So it's over five years ago already.
>
> gcc-3.2.0 is from 2002, I think. At some point you just have to say
> "caring about a 15 year old compiler is ridiculous"
>
> The main reason we have fairly aggressively supported old compilers
> tends to be some odder architectures that don't have good support, so
> people use various random "this works for me" versions.

I thought it was because akpm still used Fedora Core 6. :)

At some point, it would be nice to skip way forward and require a
compiler without the 16-byte-stack-alignment bug, too.

--Andy