On Thu, Aug 13, 2020 at 09:23:35AM -0600, Jeff Law wrote:
On Thu, 2020-08-13 at 11:13 -0400, Omair Majid wrote:
> Jeff Law <law(a)redhat.com> writes:
>
> > I can't help with the untagging, but I'm here if there's anything
> > going wrong with the system tools that is ultimately affecting dotnet.
>
> Thanks.
>
> Just for context:
>
> .NET Core uses a bundled (and modified) copy of libunwind for unwinding
> the stack. This version doesn't work on aarch64 when built with one of
> the new CFLAGS introduced in Fedora 33/34: -mbranch-protection=standard.
>
> The upstream version of libunwind (the Fedora libunwind package) is also
> broken (in a completely different way) for aarch64 from a .NET Core
> point of view too.
>
> For now, my "fix" is to remove `-mbranch-protection=standard` from
> CFLAGS on aarch64 to get things working.
That may work in the immediate term, but I think we'll need a better fix in the
long term -- I believe the plan is to have the BTI/PAC stuff enabled by default
for RHEL 9. We can bug ARM to get upstream libunwind fixed if that would help
(we meet with them Monday -- you'd be welcome to join to provide technical
context to the libunwind issue).
FYI for the list:
We talked about this on irc. We cannot untag that package as it's long
since been shipped out. However, a side tag can be used to build against
the old version:
* create side tag
* tag old version into it
* build new version against old working version.
* merge side tag
This should allow everything to build and not disrupt all the people who
have the current version already installed, etc.
kevin