Re: x86-64: Maintain 16-byte stack alignment

From: Herbert Xu
Date: Thu Jan 12 2017 - 02:06:05 EST


On Tue, Jan 10, 2017 at 09:05:28AM -0800, Linus Torvalds wrote:
>
> I'm pretty sure we have random asm code that may not maintain a
> 16-byte stack alignment when it calls other code (including, in some
> cases, calling C code).
>
> So I'm not at all convinced that this is a good idea. We shouldn't
> expect 16-byte alignment to be something trustworthy.

So what if we audited all the x86 assembly code to fix this? Would
it then be acceptable to do a 16-byte aligned stack?

On the face of it it doesn't seem to be a huge amount of code
assuming they mostly live under arch/x86.

Cheers,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt