Re: time to workaround libc/13097 in fsf gdb?

Pedro Alves
2014-09-12T12:14:44Z

On 09/12/2014 12:54 PM, Jan Kratochvil wrote:
> On Thu, 11 Sep 2014 18:37:02 +0200, Pedro Alves wrote:
>> Also, we know the address of the vDSO/gate (symfile-mem.c). Can't
>> we use that to match instead of the name?
> [...]
>> ISTR having seen a patch that does that, but I can't seem to find it.
>
> Re: [patch+7.5.1] Work around PR libc/13097 "linux-vdso.so.1" #3
> https://sourceware.org/ml/gdb-patches/2012-11/msg00636.html
> Message-ID: <20121125181505.GA26194@host2.jankratochvil.net>
>
> It is pending/unreviewed/unapproved.

Ah, yeah, I think that was it.

I was more inclined to leave the vdso in the shared library list
though, like ldd does, than filtering it out. Like, similar to
your gdbarch_solib_file_not_found_is_ok patch, but look at the
addresses rather than filenames in the hook. I'm not sure
whether that'd complicate things too much.

> Also I am not sure it is really still an issue on latest upstream glibc, it is
> not an issue on Fedora 21 x86_64 glibc with the reproducer from:
> https://sourceware.org/bugzilla/show_bug.cgi?id=13097
>
> (That is old Fedoras workarounded it in glibc, then some Fedoras exposed the
> issue in GDB but now it is not visible - so either Fedoras workaround it again
> or just upstream glibc switched/workarounds it also.)

Thanks,
Pedro Alves