Merge tag 'perf-urgent-for-mingo-4.20-20181121' of git://git.kernel.org/pub/scm/linux...

Pull perf/urgent fixes:

- Update kernel ABI headers, one of them lead to a small change in
  the ioctl 'cmd' beautifier in 'perf trace' to support the new ISO7816
  commands. (Arnaldo Carvalho de Melo)

- Restore proper cwd on return from mnt namespace (Jiri Olsa)

- Add feature check for the get_current_dir_name() function used in the
  namespace fix from Jiri, that is not available in systems such as
  Alpine Linux, which uses the  musl libc (Arnaldo Carvalho de Melo)

- Fix crash in 'perf record' when synthesizing the unit for events such
  as 'cpu-clock' (Jiri Olsa)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>