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