perf test shell: Add 'probe_vfs_getname' shell test

Commit-ID:  a3534842ddd04675abc67e80432aacc01670cca8
Gitweb:     http://git.kernel.org/tip/a3534842ddd04675abc67e80432aacc01670cca8
Author:     Arnaldo Carvalho de Melo <[email protected]>
AuthorDate: Thu, 3 Aug 2017 16:54:53 -0300
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Fri, 11 Aug 2017 16:06:28 -0300

perf test shell: Add 'probe_vfs_getname' shell test

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
  #

---
 tools/perf/tests/shell/probe_vfs_getname.sh | 30 +++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

new file mode 100755
index 0000000..d5f5248
@@ -0,0 +1,30 @@
+# Add vfs_getname probe to get syscall args filenames
+#
+# Arnaldo Carvalho de Melo <[email protected]>, 2017
+
+perf probe -l | grep -q probe:vfs_getname
+had_vfs_getname=$?
+
+cleanup_probe_vfs_getname() {
+	if [ $had_vfs_getname -eq 1 ] ; then
+		perf probe -q -d probe:vfs_getname
+	fi
+}
+
+add_probe_vfs_getname() {
+	local verbose=$1
+	if [ $had_vfs_getname -eq 1 ] ; then
+               line=$(perf probe -L getname_flags | egrep 'result.*=.*filename;' | sed -r 's/[[:space:]]+([[:digit:]]+)[[:space:]]+result->uptr.*/\1/')
+               perf probe $verbose "vfs_getname=getname_flags:${line} pathname=result->name:string"
+	fi
+}
+
+skip_if_no_debuginfo() {
+	add_probe_vfs_getname -v 2>&1 | grep -q "^Failed to find the path for kernel" && return 2
+	return 1
+}
+
+add_probe_vfs_getname || skip_if_no_debuginfo
+err=$?
+cleanup_probe_vfs_getname
+exit $err