Re: [RFC v4 00/18] objtool: Add support for arm64

From: Raphael Gault
Date: Fri Aug 23 2019 - 08:00:48 EST

Hi Josh,

On 8/22/19 8:56 PM, Josh Poimboeuf wrote:
On Fri, Aug 16, 2019 at 01:23:45PM +0100, Raphael Gault wrote:

Changes since RFC V3:
* Rebased on tip/master: Switch/jump table had been refactored
* Take Catalin Marinas comments into account regarding the asm macro for
marking exceptions.

As of now, objtool only supports the x86_64 architecture but the
groundwork has already been done in order to add support for other
architectures without too much effort.

This series of patches adds support for the arm64 architecture
based on the Armv8.5 Architecture Reference Manual.

Objtool will be a valuable tool to progress and provide more guarentees
on live patching which is a work in progress for arm64.

Once we have the base of objtool working the next steps will be to
port Peter Z's uaccess validation for arm64.

Hi Raphael,

Sorry about the long delay. I have some comments coming shortly.

One general comment: I noticed that several of the (mostly minor)
suggested changes I made for v1 haven't been fixed.

I'll try to suggest them again here for v4, so you don't need to go back
and find them. But in the future please try to incorporate all the
comments from previous patch sets before posting new versions. I'm sure
it wasn't intentional, as you did acknowledge and agree to most of the
changes. But it does waste people's time and goodwill if you neglect to
incorporate their suggestions. Thanks.

Indeed, sorry about that.

Thanks for you comments, I will do my best to address them shortly. However, I won't have access to my professional emails for a little while and probably won't be able to work on this before at least a week. I'll try to have a new soon though and use my personal email.


Raphael Gault