2018-12-14 21:49:14

by Laura Abbott

Subject: Unwinding regression with 379d98ddf413 ("x86: vdso: Use $LD instead of $CC to link")

Hi,

There are two reports of a regression with unwinding with
379d98ddf413 ("x86: vdso: Use $LD instead of $CC to link")

https://bugzilla.kernel.org/show_bug.cgi?id=201741
https://bugzilla.redhat.com/show_bug.cgi?id=1659295

It looks like the unwinding information has been
stripped out. Any ideas?

Thanks,
Laura

2018-12-14 22:25:59

by Alistair Strachan

Subject: Re: Unwinding regression with 379d98ddf413 ("x86: vdso: Use $LD instead of $CC to link")

Hi Laura,

On Fri, Dec 14, 2018 at 1:48 PM Laura Abbott <[email protected]> wrote:
> Hi,
>
> There are two reports of a regression with unwinding with
> 379d98ddf413 ("x86: vdso: Use $LD instead of $CC to link")
>
> https://bugzilla.kernel.org/show_bug.cgi?id=201741
> https://bugzilla.redhat.com/show_bug.cgi?id=1659295
>
> It looks like the unwinding information has been
> stripped out. Any ideas?

Sorry about this. I missed a critical flag (--eh-frame-hdr) that gcc
specifies implicitly when converting the Makefile to invoke ld
directly. This went unnoticed because the linking of vmlinux (which
also uses ld directly) does not need this information, so it does not
specify the flag. Sending a verified fix now.

> Thanks,
> Laura