libc.so.6: CPU ISA level is lower than required

libc.so.6: CPU ISA level is lower than required

[Khem Raj]

Hi All

In Yocto we use -march=core2 to compile glibc and rest of system for
x86_64 and after upgrading to 2.33, we are seeing an error

/lib/libc.so.6: CPU ISA level is lower than required

when executing the binaries on qemu with -cpu core2duo option, this
works out ok If I use
-cpu Nehalem or newer.

I know ldso in 2.33 has got new hwcaps features to check the x86 ISA
and perhaps thats causing it
but I am trying to find why would it reject -cpu core2duo from qemu
when we also ensured
that -march and -mtune values stay at core2 when compiling glibc and
rest of system.

I was looking at

https://sourceware.org/git/?p=glibc.git;a=commit;h=ecce11aa0752735c4fd730da6e7c9e0b98e12fb8

since that seems to be the cause and checking if there was some option
to configure it out.
I wonder if there is minimal ISA default now which is newer than core2 perhaps ?

I am looking for some help on how can we get to this point and what is
the right way forward.

Thanks
-Khem

Re: libc.so.6: CPU ISA level is lower than required

[H.J. Lu]

On Wed, Feb 3, 2021 at 12:17 PM Khem Raj via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> Hi All
>
> In Yocto we use -march=core2 to compile glibc and rest of system for
> x86_64 and after upgrading to 2.33, we are seeing an error
>
> /lib/libc.so.6: CPU ISA level is lower than required
>
> when executing the binaries on qemu with -cpu core2duo option, this
> works out ok If I use
> -cpu Nehalem or newer.
>
> I know ldso in 2.33 has got new hwcaps features to check the x86 ISA
> and perhaps thats causing it
> but I am trying to find why would it reject -cpu core2duo from qemu
> when we also ensured
> that -march and -mtune values stay at core2 when compiling glibc and
> rest of system.
>
> I was looking at
>
> https://sourceware.org/git/?p=glibc.git;a=commit;h=ecce11aa0752735c4fd730da6e7c9e0b98e12fb8
>
> since that seems to be the cause and checking if there was some option
> to configure it out.
> I wonder if there is minimal ISA default now which is newer than core2 perhaps ?
>
> I am looking for some help on how can we get to this point and what is
> the right way forward.
>
> Thanks
> -Khem

https://sourceware.org/pipermail/libc-alpha/2021-February/122297.html

-- 
H.J.