4.21 build failure

[Eugene Syromiatnikov]

On Mon, Feb 19, 2018 at 09:21:59PM +0100, Andreas Schwab wrote:
> On Feb 19 2018, Eugene Syromiatnikov <esyr at redhat.com> wrote:
> 
> > On Mon, Feb 19, 2018 at 07:31:57PM +0100, Andreas Schwab wrote:
> >> On Feb 19 2018, Eugene Syromiatnikov <esyr at redhat.com> wrote:
> >> 
> >> > On Thu, Feb 15, 2018 at 12:39:15AM +0100, Andreas Schwab wrote:
> >> >> 4.21 fails to build for aarch64:
> >> >> 
> >> >> checking gnu/stubs-32.h usability... no
> >> >> checking gnu/stubs-32.h presence... no
> >> >> checking for gnu/stubs-32.h... no
> >> >> configure: Created empty gnu/stubs-32.h
> >> >> checking for m32 personality compile support... no
> >> >> checking whether to enable m32 personality support... no
> >> >> configure: error: Cannot enable m32 personality support
> >> >
> >> > As noted in NEWS, strace now enforces mpers support by default (in order
> >> > to make aware of the possibilty of incorrect non-native personality
> >> > decoding early); looks like your compiler doesn't support producing
> >> > binaries for the compat personality.  You can either try to use another
> >> > compiler or provide --disable-mpers to the configure script.
> >> 
> >> There is no such thing as -m32 on aarch64 or riscv64.  There is only
> >> -mabi=ilp32 or -mabi=ilp32d.
> >
> > Are you aware of any differences between ARMv7 EABI and AArch32 ABI?
> 
> How is that relevant?  This is about aarch64 and riscv64.

Well, current implementation of AArch64 compat in strace assumes it's
identical to ARMv7 EABI, and I'm trying to figure out how to build mpers
support for it and test it.  And, judging by [1], it looks like ilp32 ABI is
more akin to x32, and it is not supported at all by strace at the moment.

[1] https://wiki.linaro.org/Platform/arm64-ilp32