[binutils] BUG: 2.33.1-2.1 generates invalid code for arm

by **vicencb** » Sat Jan 11, 2020 11:03 am

Hello,
since gcc was updated from gcc-8.3.0-1-aarch64 to gcc-9.2.0-4-aarch64 it generates invalid code.
Some programs compiled with 9.2 (like e.g. the mesa and kernel) generate a SIGILL (Illegal instruction) exception.
mesa-19.3.2-1-aarch64 from the repository is known to contain such illegal instructions.
Please, revert the gcc update before the whole repository is tainted with the new gcc.

Regards,
Vicenç.

by **vicencb** » Sat Jan 11, 2020 1:11 pm

Hi again,
i've narrowed down the issue and it may not be gcc but binutils.
binutils-2.33.1-2-aarch64 and gcc-9.2.0-4-aarch64 can generate a valid kernel that boots fine on aarch64
binutils-2.33.1-2.1-aarch64 and gcc-9.2.0-4-aarch64 generate an invalid kernel that does not boot on aarch64
The package mesa-19.3.2-1-aarch64 reported to be known bad was updated with both: new gcc and new binutils (among others)
So, please, instead of reverting gcc, revert binutils.

by **vicencb** » Sat Jan 11, 2020 4:42 pm

The root cause of the issue has been found and is in the process of being fixed.
Comunication has been through IRC.
This bug report can be closed now.

Website · by **graysky** » Sat Jan 11, 2020 4:57 pm

Just to be clear, the forums aren't a formal bug tracker. Would you mind summarizing the fix you discovered on IRC?

by **vicencb** » Sat Jan 11, 2020 5:53 pm

I know a forum is not a proper bug tracker. I've posted here following indications from
https://archlinuxarm.org/about/contact
and following instructions from
viewtopic.php?f=3&t=2675#p15134

Anyways, the bug is fixed with binutils-2.33.1-2.2-aarch64 which includes an extra patch posted upstream:
https://sourceware.org/bugzilla/show_bu ... d=25210#c5
Then some affected packages that have been build with the bad binutils need to be rebuild.
At of the time of writing the list includes:
mesa-19.3.2-2-aarch64
and maybe networkmanager or libnm

Regards

by **risto3** » Sat Jan 11, 2020 6:37 pm

perhaps sddm? viewtopic.php?f=65&t=14207

by **vicencb** » Sat Jan 11, 2020 6:49 pm

not sddm, only aarch64 packages with a build date greater than or equal to
Wed Jan 8 14:52:58 2020 UTC
can be related to this bug.

That said, it could be a library loaded by sddm...

by **risto3** » Sun Jan 12, 2020 10:12 am

as swrast_dri.so comes from mesa, this appears to be the case.
After updating with the new builds with fixed binutils, the problem seems luckily resolved.

cheers