[ Upstream commit 03fa483821c0b4db7c2b1453d3332f397d82313f ]

Some kernels, like 4.19.13-300.fc29.x86_64 in fedora 29, fail with the
existing probe definition asking for the contents of result->name,
working when we ask for the 'filename' variable instead, so add a
fallback to that.

Now those tests are back working on fedora 29 systems with that kernel:

  # perf test vfs_getname
  65: Use vfs_getname probe to get syscall args filenames   : Ok
  66: Add vfs_getname probe to get syscall args filenames   : Ok
  67: Check open filename arg using perf trace + vfs_getname: Ok
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-klt3n0i58dfqttveti09q3fi@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

In some situations the vfs_getname is being added both as requested and
with a _1 suffix (inlines?):

  probe:vfs_getname_1  (on getname_flags:63@acme/git/linux/fs/namei.c with pathname)

This ends up making the cleanup to miss that one, as it removes just
'probe:vfs_getname', which makes the second test to use this probe point
to fail, since it finds that leftover from the first test, use a
wildcard to remove both.

Before:

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

After:

  # perf test 60 61 62 63
  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
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-2k5kutwr4ds36adiakyb4yvy@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Since we do not specify bash (and/or zsh) as a requirement, use the
standard error redirection that is more widely supported.
Signed-off-by: NKim Phillips <kim.phillips@arm.com>
Link: http://lkml.kernel.org/n/tip-ji5mhn3iilgch3eaay6csr6z@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

If that is the case, or if the required lib is not present, e.g.
elfutils-devel in Fedora systems, then just skip the tests requiring
DWARF analysis.

Before:

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

After:

  # perf test vfs_getname
  60: Use vfs_getname probe to get syscall args filenames   : Skip
  62: Check open filename arg using perf trace + vfs_getname: Skip
  63: Add vfs_getname probe to get syscall args filenames   : Skip
  #

Then, reinstalling elfutils-devel, rebuilding the tool and running
again:

  # perf test vfs_getname
  60: Use vfs_getname probe to get syscall args filenames   : 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: NKim 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-d67tvn401fxrwr97pu5ihfb1@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

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: NKim 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.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-3zxjswdbs2au3ih0rino0iy1@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Multiple tests will be able to reuse these functions, to test things
like perf report, 'trace', etc, using this probe.

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-48xagvozhouhyi8fjota6o2d@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

First perf shell test:

  # perf test vfs_getname
  60: Add vfs_getname probe to get syscall args filenames: Ok
  #

In verbose mode:

  # perf test -v vfs_getname
  60: Add vfs_getname probe to get syscall args filenames:
  --- start ---
  test child forked, pid 19146
  Added new event:
    probe:vfs_getname    (on getname_flags:72 with pathname=result->name:string)

  You can now use it in all perf tools, such as:

	  perf record -e probe:vfs_getname -aR sleep 1

  test child finished with 0
  ---- end ----
  Add vfs_getname probe to get syscall args filenames: Ok
  #

And if the vmlinux file is not found:

  # mv ../build/v4.12.0-rc6+/vmlinux ../build/v4.12.0-rc6+/vmlinux.hidden
  # perf test vfs_getname
  60: Add vfs_getname probe to get syscall args filenames: Skip
  #

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-8f3n22c1yn516ev30s603ow2@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>