Re: [PATCH v2 0/3] Support rseq on arm64

[Will Deacon]

On Mon, Jul 09, 2018 at 01:17:54PM -0400, Mathieu Desnoyers wrote:
> ----- On Jul 9, 2018, at 12:53 PM, Will Deacon will.deacon@xxxxxxx wrote:
> 
> > On Mon, Jul 09, 2018 at 12:06:22PM -0400, Mathieu Desnoyers wrote:
> >> ----- On Jul 9, 2018, at 10:19 AM, Will Deacon will.deacon@xxxxxxx wrote:
> >> 
> >> > Hello,
> >> > 
> >> > This is version two of the patches previously posted here:
> >> > 
> >> > http://lkml.kernel.org/r/1529949285-11013-1-git-send-email-will.deacon@xxxxxxx
> >> > 
> >> > Changes since v1 include:
> >> > 
> >> >  * Move abort handler in-line to avoid possibility of it being
> >> >    out-of-range for conditional branch instructions
> >> > 
> >> > I've tested both native and compat (little-endian only) with the selftests
> >> > and they pass successfully on my Seattle box.
> >> 
> >> For the whole series:
> >> 
> >> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
> > 
> > Thanks, Mathieu! Are you ok with me taking this via the arm64 tree for
> > 4.19 once I have an Ack for the asm-generic change, or would you rather
> > this went via somewhere else?
> 
> Adding Thomas Gleixner in CC. He has been picking up the rseq bits for
> 4.18. I've noticed it was rather easier to gather rseq stuff through a
> single tree (less chances of confusion).

Whilst I can see that making some sense for the selftests (particularly
if the ABI is liable to further changes before 4.18 is released), I'd
prefer to take the arm64 bits via the arm64 tree, as they will conflict
with some ongoing work to rewrite the syscall entry path in C which I
plan to queue in the next week (pending final testing results).

> Also, support for additional architectures (e.g. MIPS) was added to rseq
> after rc1. Is it too late to merge arm64 support targeting 4.18 ?

Personally, I don't see the rush, but I won't stop anybody who wants to
try steam-rollering them into mainline ;)

Will