perf test shell: Check if 'perf probe' is available, skip tests if not

Add a library function that checks if 'perf probe' is built into the
tool being tested, skipping tests that need it.

Testing it on a system after removing the library needed to build
'probe' as a perf subcommand:

  # perf test ping vfs_getname
  59: Use vfs_getname probe to get syscall args filenames   : Skip
  60: probe libc's inet_pton & backtrace it with ping       : Skip
  61: Check open filename arg using perf trace + vfs_getname: Skip
  62: Add vfs_getname probe to get syscall args filenames   : Skip
  # perf probe
  perf: 'probe' is not a perf-command. See 'perf --help'.
  #

Now reinstalling elfutils-libelf-devel on this Fedora 26 system to
rebuild perf and then retest this:

  # perf test ping vfs_getname
  60: Use vfs_getname probe to get syscall args filenames   : Ok
  61: probe libc's inet_pton & backtrace it with ping       : Ok
  62: Check open filename arg using perf trace + vfs_getname: Ok
  63: Add vfs_getname probe to get syscall args filenames   : Ok
  #

Reported-by: Kim Phillips <kim.phillips@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ctdck2gzsskqhjzu3ebb62zm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/tools/perf/tests/shell/lib/probe_vfs_getname.sh b/tools/perf/tests/shell/lib/probe_vfs_getname.sh
index 3eaddf190a30..46c1bb707600 100644
--- a/tools/perf/tests/shell/lib/probe_vfs_getname.sh
+++ b/tools/perf/tests/shell/lib/probe_vfs_getname.sh
@@ -1,6 +1,6 @@
 # Arnaldo Carvalho de Melo <acme@kernel.org>, 2017
 
-perf probe -l | grep -q probe:vfs_getname
+perf probe -l |& grep -q probe:vfs_getname
 had_vfs_getname=$?
 
 cleanup_probe_vfs_getname() {