Re: [PATCH v4 00/12] arm+arm64: vdso unification to lib/vdso/

From: Mark Salyzyn
Date: Wed Nov 01 2017 - 10:45:09 EST

On 11/01/2017 02:40 AM, Will Deacon wrote:
On Tue, Oct 31, 2017 at 06:04:19PM -0400, Jon Masters wrote:
On 10/31/2017 02:30 PM, Mark Salyzyn wrote:
Take an effort to recode the arm64 vdso code from assembler to C
previously submitted by Andrew Pinski <apinski@xxxxxxxxxx>, rework
it for use in both arm and arm64, overlapping any optimizations
for each architecture. But instead of landing it in arm64, land the
result into lib/vdso and unify both implementations to simplify
future maintenance. This will act as the basis for implementing
arm64 vdso32 in the future.
In the original patch series, our QE folks found a problem that lead to
its revertion from our internal trees. I've pinged them to check this
latest version and followup if we see the same failures now.
Could you elaborate a bit on the problem you found, please? Even if you
don't see it with this series, it doesn't mean it isn't lurking somewhere
else (potentially even in mainline!).

Will

Interested too!

NB: I expect there can also be some patch series confusion

I have taken two separate, stalling and publicized efforts (arm64 vdso64->C apinski@ and vdso32 Kevin.brodsky@), merged them, tested them, divided them into relatively orthogonal elements, then broke them into smaller independent patch series' (divide and conquer). The final set of vdso32 changes are still pending as I watch each of the three prior smaller patch series' morph on the road to approval. The broken up series created thus far are:

[PATCH] arm64: compat: Remove leftover variable declaration (approved)

[PATCH vx x/3] arm64: compat: Add CONFIG_KUSER_HELPERS (pending)

[PATCH] arm64: compat: Expose offset to registers in sigframes (pending)

[PATCH vx x/12] arm+arm64: vdso unification to lib/vdso (pending, this one)

My suspicion is the final vdso32 changes (blocked by all of these + clangizing, not yet republished as rebased) could be the culprit Jon Masters could be speaking of?

Sincerely -- Mark Salyzyn