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.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
--- /dev/null
+# Add vfs_getname probe to get syscall args filenames
+#
+# Arnaldo Carvalho de Melo <acme@kernel.org>, 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