[PATCH v2 02/10] Finish move of clock_* functions to libc.

[Florian Weimer]

* Zack Weinberg:

> diff --git a/rt/Versions b/rt/Versions
> index 91e3fd2a20..84d1345420 100644
> --- a/rt/Versions
> +++ b/rt/Versions
> @@ -1,15 +1,3 @@
> -libc {
> -  GLIBC_2.17 {
> -    # c*
> -    clock_getres; clock_gettime; clock_settime; clock_getcpuclockid;
> -    clock_nanosleep;
> -  }
> -  GLIBC_PRIVATE {
> -    __clock_getres; __clock_gettime; __clock_settime; __clock_getcpuclockid;
> -    __clock_nanosleep;
> -  }
> -}

Sorry, you cannot remove the GLIBC_2.17 symbol version in this way,
otherwise old binaries will fail to load.  You need to leave behind a
dummy function definition.  See __libpthread_version_placeholder for how
I handled this in the libpthread/vfork case.

I think we need to bring back the file version information in the ABI
lists because it is part of the ABI, after all.

We have received a bug report that the librt IFUNC resolvers actually
cause programs not to start:

  <https://sourceware.org/bugzilla/show_bug.cgi?id=24959>

I would appreciate if you could mention this bug number in your fix.

Thanks,
Florian