From 43f6345c9605c0fad57abfe31dda8951f6630ebf Mon Sep 17 00:00:00 2001
From: "Frank Ch. Eigler" <fche@redhat.com>
Date: Tue, 6 Nov 2018 16:26:57 -0500
Subject: [PATCH 22/32] standardize ktime_get_ns() across lkm, bpf runtimes
Make sure ktime_get_ns() is available across runtimes. In the case of
bpf, add a userspace helper to implement the function. Add test case.
Add a systemtap.bpf/nobpf.exp test driver, which runs all the
bpf_tests but specifically without "--bpf", in the hope that all those
scripts should run on the normal backend too. PR23866 blocks some of
that at the moment.
---
stapbpf/bpfinterp.cxx | 13 ++
tapset/bpf/time.stp | 2 +-
tapset/linux/timestamp_monotonic.stp | 11 ++
testsuite/systemtap.bpf/bpf_tests/ktime_get_ns.stp | 33 +++++
testsuite/systemtap.bpf/nonbpf.exp | 152 +++++++++++++++++++++
5 files changed, 210 insertions(+), 1 deletion(-)
create mode 100644 testsuite/systemtap.bpf/bpf_tests/ktime_get_ns.stp
create mode 100644 testsuite/systemtap.bpf/nonbpf.exp
diff --git a/stapbpf/bpfinterp.cxx b/stapbpf/bpfinterp.cxx
index fe6eacc50..13ac8ee71 100644
--- a/stapbpf/bpfinterp.cxx
+++ b/stapbpf/bpfinterp.cxx
@@ -162,6 +162,16 @@ bpf_sprintf(std::vector<std::string> &strings, char *fstr,
return reinterpret_cast<uint64_t>(strings.back().c_str());
}
+uint64_t
+bpf_ktime_get_ns()
+{
+ struct timespec t;
+ clock_gettime (CLOCK_BOOTTIME, &t);
+ return (t.tv_sec * 1000000000) + t.tv_nsec;
+}
+
+
+
uint64_t
bpf_interpret(size_t ninsns, const struct bpf_insn insns[],
std::vector<int> &map_fds, FILE *output_f)
@@ -374,6 +384,9 @@ bpf_interpret(size_t ninsns, const struct bpf_insn insns[],
case BPF_FUNC_map_delete_elem:
dr = bpf_delete_elem(map_fds[regs[1]], as_ptr(regs[2]));
break;
+ case BPF_FUNC_ktime_get_ns:
+ dr = bpf_ktime_get_ns();
+ break;
case BPF_FUNC_trace_printk:
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wformat-nonliteral"
diff --git a/tapset/bpf/time.stp b/tapset/bpf/time.stp
index ee615330c..a1c827e73 100644
--- a/tapset/bpf/time.stp
+++ b/tapset/bpf/time.stp
@@ -12,7 +12,7 @@
* Description: This function returns the system ktime.
*/
function ktime_get_ns:long ()
-%{ /* bpf */ /* pure */ /* unprivileged */ /* stable */
+%{ /* bpf */ /* pure */ /* unprivileged */
0x85, 0, 0, 0, 5; /* call BPF_FUNC_ktime_get_ns */
0xbf, $$, 0, 0, 0 /* movx $$, r0 */
%}
diff --git a/tapset/linux/timestamp_monotonic.stp b/tapset/linux/timestamp_monotonic.stp
index 6b6d445de..c8d142369 100644
--- a/tapset/linux/timestamp_monotonic.stp
+++ b/tapset/linux/timestamp_monotonic.stp
@@ -148,3 +148,14 @@ function local_clock_ms:long () {
function local_clock_s:long () {
return local_clock_ns() / 1000000000;
}
+
+
+/**
+ * sfunction ktime_get_ns - Number of nanoseconds since boot
+ *
+ * Description: This function returns the system ktime.
+ */
+function ktime_get_ns:long () %{
+ /* pure */ /* unprivileged */
+ STAP_RETURN ((int64_t) ktime_get_ns());
+%}
diff --git a/testsuite/systemtap.bpf/bpf_tests/ktime_get_ns.stp b/testsuite/systemtap.bpf/bpf_tests/ktime_get_ns.stp
new file mode 100644
index 000000000..0b1d98e94
--- /dev/null
+++ b/testsuite/systemtap.bpf/bpf_tests/ktime_get_ns.stp
@@ -0,0 +1,33 @@
+global t1, t2, t3
+
+probe begin {
+ printf("BEGIN\n")
+ t1 = ktime_get_ns() // bpfinterp.cxx
+}
+
+probe timer.s(1) {
+ t2 = ktime_get_ns() // kernel bpf - XXX watch if timer.s() moves to userspace
+}
+
+probe perf.type(1).config(0).hz(1) {
+ t3 = ktime_get_ns() // kernel bpf
+}
+
+
+/*
+probe kernel.function("SOMETHING") { # to trigger kernel side bpf func
+ t3 = ktime.get.ns()
+}
+*/
+
+
+probe timer.s(5) {
+ exit()
+}
+
+probe end {
+ if (t1 > 0 && t2 > 0 && t3 > 0)
+ printf("END PASS\n")
+ else
+ printf("END FAIL\n")
+}
diff --git a/testsuite/systemtap.bpf/nonbpf.exp b/testsuite/systemtap.bpf/nonbpf.exp
new file mode 100644
index 000000000..35f6a7c99
--- /dev/null
+++ b/testsuite/systemtap.bpf/nonbpf.exp
@@ -0,0 +1,152 @@
+# bpf.exp
+#
+# To restrict scripts to test, set the CHECK_ONLY environment variable.
+# For example, to only test the printf and uprobes scripts, run:
+#
+# make installcheck RUNTESTFLAGS="nonbpf.exp" CHECK_ONLY="printf uprobes"
+
+set testdir "$srcdir/$subdir/bpf_tests"
+
+# All tests should start by printing "BEGIN". If OUTPUT_STR is "", then
+# the test passes if "END PASS" is read and fails if "END FAIL" is read. Otherwise
+# the test passes when "${OUTPUT_STR}END" is read and fails if END is read without
+# OUTPUT_STR preceeding it.
+proc stapnonbpf_run { TEST_NAME OUTPUT_STR args } {
+ global rc
+ set rc -1
+ set begin_str "BEGIN"
+ set pass_str [expr { $OUTPUT_STR == "" ? "END PASS" : "${OUTPUT_STR}END" }]
+ set fail_str [expr { $OUTPUT_STR == "" ? "END FAIL" : "END" }]
+
+ # return codes
+ set pass 0
+ set fail 1
+ set bad_output 2
+ set eof_start 3
+ set eof_end 4
+ set timeout_start 5
+ set timeout_end 6
+ set invalid_prog 7
+ set comp_err 8
+
+ set cmd [concat stap -v $args]
+ # don't the following: ... $test_file_name could be some transient or leftover file
+ # if [file readable $test_file_name] { lappend cmd $test_file_name }
+
+ send_log "executing: $cmd\n"
+ eval spawn $cmd
+ set mypid [exp_pid -i $spawn_id]
+ expect {
+ -timeout 30
+ -re {^WARNING: cannot find module [^\r]*DWARF[^\r]*\r\n} {exp_continue}
+ -re {^WARNING: No unwind data for /.+\r\n} {exp_continue}
+ -re {^Pass\ ([1234]):[^\r]*\ in\ ([0-9]+)usr/([0-9]+)sys/([0-9]+)real\ ms\.\r\n}
+ {set pass$expect_out(1,string) "\t$expect_out(2,string)\t$expect_out(3,string)\t$expect_out(4,string)"; exp_continue}
+ -re {^Pass\ ([34]): using cached [^\r]+\r\n}
+ {set pass$expect_out(1,string) "\t0\t0\t0"; exp_continue}
+ -re {^Passes: via server [^\r]* using [^\r]* in [0-9]+usr/[0-9]+sys/[0-9]+real ms\.\r\n} {exp_continue}
+ -re {^Pass 5: starting run.\r\n} {exp_continue}
+ -re $begin_str {
+ # By default, "expect -re" will match up to 2000 chars.
+ # Increase this to 8K worth of data.
+ exp_match_max 8192
+
+ # Avoid PR17274 to propagate
+ set origexpinternal 1
+ if {"[exp_internal -info]" == "0"} {set origexpinternal 0}
+ #exp_internal 0
+
+ expect {
+ -timeout 20
+ -re $pass_str {
+ set rc $pass
+ }
+ -re $fail_str {
+ set rc $fail
+ }
+ default {
+ set rc $bad_output
+ }
+ timeout {
+ set rc $timeout_end
+ kill -INT -$mypid
+ }
+ eof { set rc $eof_end }
+ }
+ exp_internal $origexpinternal
+ }
+ -re "semantic error:" { set rc $comp_err }
+ timeout {
+ set rc $timeout_start
+ kill -INT -$mypid
+ }
+ eof { set rc $eof_start }
+ }
+ # again for good measure with KILL after 3s
+ kill -INT -$mypid 3
+ catch close
+ wait
+ return $rc
+}
+
+proc get_output_str { test } {
+ global res
+ switch $test {
+ printf.stp { set res [string repeat "abcd123456" 3] }
+ sprintf.stp { set res [string repeat "0123456789" 2] }
+ string1.stp { set res {begin\[str0str1str2str3\]probe\[str0str1str2str3\]end\[str0str1str2str3\]} }
+ string2.stp { set res {probe0\[str0str1str2str3\]probe1\[str0str1str2str3\]end\[str0str1str2str3\]} }
+ default { set res "" }
+ }
+ return $res
+}
+
+if {[info exists env(CHECK_ONLY)]} {
+ set all_files [lsort [glob -nocomplain $testdir/*.stp]]
+ set stap_files ""
+ foreach file $env(CHECK_ONLY) {
+ if {[lsearch $all_files $testdir/$file.stp] >= 0} {
+ set stap_files "$stap_files $testdir/$file.stp"
+ }
+ }
+} else {
+ set stap_files [lsort [glob -nocomplain $testdir/*.stp]]
+}
+
+foreach file $stap_files {
+ global mypid
+ set mypid 0
+ set test [file tail $file]
+ if {! [installtest_p]} { untested $test; continue }
+
+ # create a process for the tests that require one
+ switch $test {
+ uprobes.stp {
+ eval spawn /usr/bin/sleep 20
+ set mypid [exp_pid -i $spawn_id]
+ }
+ }
+
+ set output_str [get_output_str $test]
+ verbose -log "Running $file"
+ switch [stapnonbpf_run $test $output_str $file] {
+ 0 { pass $test }
+ 1 { fail "$test incorrect result" }
+ 2 { fail "$test unexpected output" }
+ 3 { fail "$test eof (startup)" }
+ 4 { fail "$test eof (shutdown)" }
+ 5 { fail "$test timeout (startup)" }
+ 6 { fail "$test timeout (startup)" }
+ 7 { fail "$test invalid bpf program" }
+ 8 { fail "$test compilation" }
+ default { fail "$test unknown return value" }
+ }
+
+ if { $mypid > 0 } {
+ kill -INT -$mypid 3
+ catch close
+ wait
+ }
+}
+
+
--
2.14.5