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[PATCH] Add new built-in tapset function quit()
- From: "Yichun Zhang (agentzh)" <agentzh at gmail dot com>
- To: systemtap at sourceware dot org
- Cc: "Yichun Zhang (agentzh)" <agentzh at gmail dot com>
- Date: Thu, 23 Aug 2018 18:51:32 -0700
- Subject: [PATCH] Add new built-in tapset function quit()
The new built-in tapset function quit() is similar to exit(), but it
aborts the currently executing functions and probe handlers immediately.
Works in both the kernel and dyninst runtimes. The bpf runtime is not
yet supported.
fche thinks it is already too late to change the current behavior of
exit(), hence this new function.
Also added corresponding tests for both quit() and exit().
---
runtime/dyninst/io.c | 9 ++++
runtime/linux/io.c | 13 +++++
tapset/logging.stp | 20 +++++++
testsuite/systemtap.base/exit.exp | 101 ++++++++++++++++++++++++++++++++++++
testsuite/systemtap.base/exit_1.stp | 11 ++++
testsuite/systemtap.base/exit_2.stp | 17 ++++++
testsuite/systemtap.base/exit_3.stp | 5 ++
testsuite/systemtap.base/quit.exp | 101 ++++++++++++++++++++++++++++++++++++
testsuite/systemtap.base/quit_1.stp | 11 ++++
testsuite/systemtap.base/quit_2.stp | 17 ++++++
testsuite/systemtap.base/quit_3.stp | 5 ++
translate.cxx | 4 +-
12 files changed, 312 insertions(+), 2 deletions(-)
create mode 100644 testsuite/systemtap.base/exit.exp
create mode 100644 testsuite/systemtap.base/exit_1.stp
create mode 100644 testsuite/systemtap.base/exit_2.stp
create mode 100644 testsuite/systemtap.base/exit_3.stp
create mode 100644 testsuite/systemtap.base/quit.exp
create mode 100644 testsuite/systemtap.base/quit_1.stp
create mode 100644 testsuite/systemtap.base/quit_2.stp
create mode 100644 testsuite/systemtap.base/quit_3.stp
diff --git a/runtime/dyninst/io.c b/runtime/dyninst/io.c
index b8e9568a5..f08ca575d 100644
--- a/runtime/dyninst/io.c
+++ b/runtime/dyninst/io.c
@@ -19,6 +19,9 @@
#define WARN_STRING "WARNING: "
#define ERR_STRING "ERROR: "
+// a flag to signal the exiting state for stap function calls
+static int _stp_quitting = 0;
+
enum code { INFO=0, WARN, ERROR, DBUG };
static void _stp_vlog (enum code type, const char *func, int line,
@@ -165,4 +168,10 @@ static void _stp_exit (void)
_stp_dyninst_transport_request_exit();
}
+static void _stp_quit (void)
+{
+ _stp_quitting = 1;
+ _stp_exit ();
+}
+
#endif /* _STAPDYN_IO_C_ */
diff --git a/runtime/linux/io.c b/runtime/linux/io.c
index 74a032c52..4d2e35d10 100644
--- a/runtime/linux/io.c
+++ b/runtime/linux/io.c
@@ -24,6 +24,9 @@
#error "STP_LOG_BUF_LEN is too short"
#endif
+// a flag to signal the exiting state for stap function calls
+static int _stp_quitting = 0;
+
enum code { INFO=0, WARN, ERROR, DBUG };
static void _stp_vlog (enum code type, const char *func, int line, const char *fmt, va_list args)
@@ -105,6 +108,16 @@ static void _stp_exit (void)
_stp_exit_flag = 1;
}
+/** Similar to _stp_exit(), but also sets the flag
+ * _stp_quitting.
+ */
+static void _stp_quit (void)
+{
+ _stp_quitting = 1;
+ _stp_exit ();
+}
+
+
/** Prints error message and exits.
* This function sends an error message immediately to staprun. It
* will also be sent over the bulk transport (relayfs) if it is
diff --git a/tapset/logging.stp b/tapset/logging.stp
index d09b8eb80..ae91123c7 100644
--- a/tapset/logging.stp
+++ b/tapset/logging.stp
@@ -75,6 +75,26 @@ function exit ()
/**
+ * sfunction quit - Immediately shutting down probing script.
+ *
+ * Description: This is similar to exit() but immediately stops
+ * the currently executing functions and probes.
+ */
+function quit ()
+%( runtime != "bpf" %?
+ %{ /* unprivileged */
+ atomic_set (session_state(), STAP_SESSION_STOPPING);
+ _stp_quit ();
+ %}
+%:
+ { /* unprivileged */ /* bpf */
+ _set_exit_status()
+ printf("ERROR: quit() not supported yet\n")
+ exit() /* TODO: need to abort the execution flow immediately */
+ }
+%)
+
+/**
* sfunction error - Send an error message
*
* @msg: The formatted message string
diff --git a/testsuite/systemtap.base/exit.exp b/testsuite/systemtap.base/exit.exp
new file mode 100644
index 000000000..525188c9c
--- /dev/null
+++ b/testsuite/systemtap.base/exit.exp
@@ -0,0 +1,101 @@
+set test "exit"
+set testpath "$srcdir/$subdir"
+
+if {! [installtest_p]} { untested "$test"; return }
+if {! [uretprobes_p]} { untested "$test"; return }
+
+# --- TEST 1 ---
+
+set subtest1 "TEST 1: exit() in the middle of a func body"
+foreach runtime [get_runtime_list] {
+ if {$runtime eq ""} { set runtime "kernel" }
+ set test_name "$test: $subtest1 ($runtime)"
+
+ set cmd "stap --runtime=$runtime '$srcdir/$subdir/${test}_1.stp'"
+ send_log "executing: $cmd\n"
+ set pipe [open "| sh -c {$cmd}" r]
+ set out [read $pipe]
+ set failed 0
+ if {[catch {close $pipe} stderr] != 0} { set failed 1 }
+
+ set exp_out "enter f\nleave f\nexit\n"
+ regsub -all -- {\n} $exp_out {\n} escaped_exp_out
+ if {$out eq $exp_out} {
+ pass "${test_name}: stdout matches \"$escaped_exp_out\""
+ } else {
+ fail "${test_name}: stdout fails to match \"$escaped_exp_out\": got \"$out\""
+ }
+
+ if {$failed} {
+ fail "${test_name}: exit code not zero"
+ } else {
+ pass "${test_name}: exit code is zero"
+ }
+ if {$stderr ne ""} {
+ send_log "stderr:\n$stderr"
+ }
+}
+
+# --- TEST 2 ---
+
+set subtest2 "TEST 2: exit() in the middle of a func body in a deeper func call chain"
+foreach runtime [get_runtime_list] {
+ if {$runtime eq ""} { set runtime "kernel" }
+ set test_name "$test: $subtest2 ($runtime)"
+
+ set cmd "stap --runtime=$runtime '$srcdir/$subdir/${test}_2.stp'"
+ send_log "executing: $cmd\n"
+ set pipe [open "| sh -c {$cmd}" r]
+ set out [read $pipe]
+ set failed 0
+ if {[catch {close $pipe} stderr] != 0} { set failed 1 }
+
+ set exp_out "enter g\nenter f\nleave f\nleave g\nexit\n"
+ regsub -all -- {\n} $exp_out {\n} escaped_exp_out
+ if {$out eq $exp_out} {
+ pass "${test_name}: stdout matches \"$escaped_exp_out\""
+ } else {
+ fail "${test_name}: stdout fails to match \"$escaped_exp_out\": got \"$out\""
+ }
+
+ if {$failed} {
+ fail "${test_name}: exit code not zero"
+ } else {
+ pass "${test_name}: exit code is zero"
+ }
+ if {$stderr ne ""} {
+ send_log "stderr:\n$stderr"
+ }
+}
+
+# --- TEST 3 ---
+
+set subtest3 "TEST 3: exit() in the middle of a probe handler body"
+foreach runtime [get_runtime_list] {
+ if {$runtime eq ""} { set runtime "kernel" }
+ set test_name "$test: $subtest3 ($runtime)"
+
+ set cmd "stap --runtime=$runtime '$srcdir/$subdir/${test}_3.stp'"
+ send_log "executing: $cmd\n"
+ set pipe [open "| sh -c {$cmd}" r]
+ set out [read $pipe]
+ set failed 0
+ if {[catch {close $pipe} stderr] != 0} { set failed 1 }
+
+ set exp_out "enter probe\nleave probe\n"
+ regsub -all -- {\n} $exp_out {\n} escaped_exp_out
+ if {$out eq $exp_out} {
+ pass "${test_name}: stdout matches \"$escaped_exp_out\""
+ } else {
+ fail "${test_name}: stdout fails to match \"$escaped_exp_out\": got \"$out\""
+ }
+
+ if {$failed} {
+ fail "${test_name}: exit code not zero"
+ } else {
+ pass "${test_name}: exit code is zero"
+ }
+ if {$stderr ne ""} {
+ send_log "stderr:\n$stderr"
+ }
+}
diff --git a/testsuite/systemtap.base/exit_1.stp b/testsuite/systemtap.base/exit_1.stp
new file mode 100644
index 000000000..c2dd0141a
--- /dev/null
+++ b/testsuite/systemtap.base/exit_1.stp
@@ -0,0 +1,11 @@
+function f() {
+ println("enter f");
+ exit();
+ println("leave f");
+}
+
+probe begin {
+ f();
+ printf("exit\n");
+ exit();
+}
diff --git a/testsuite/systemtap.base/exit_2.stp b/testsuite/systemtap.base/exit_2.stp
new file mode 100644
index 000000000..b747ddc0c
--- /dev/null
+++ b/testsuite/systemtap.base/exit_2.stp
@@ -0,0 +1,17 @@
+function f() {
+ println("enter f");
+ exit();
+ println("leave f");
+}
+
+function g() {
+ println("enter g");
+ f();
+ println("leave g");
+}
+
+probe begin {
+ g();
+ printf("exit\n");
+ exit();
+}
diff --git a/testsuite/systemtap.base/exit_3.stp b/testsuite/systemtap.base/exit_3.stp
new file mode 100644
index 000000000..3f3b801d1
--- /dev/null
+++ b/testsuite/systemtap.base/exit_3.stp
@@ -0,0 +1,5 @@
+probe begin {
+ println("enter probe");
+ exit();
+ println("leave probe");
+}
diff --git a/testsuite/systemtap.base/quit.exp b/testsuite/systemtap.base/quit.exp
new file mode 100644
index 000000000..97c9acbc7
--- /dev/null
+++ b/testsuite/systemtap.base/quit.exp
@@ -0,0 +1,101 @@
+set test "quit"
+set testpath "$srcdir/$subdir"
+
+if {! [installtest_p]} { untested "$test"; return }
+if {! [uretprobes_p]} { untested "$test"; return }
+
+# --- TEST 1 ---
+
+set subtest1 "TEST 1: quit() in the middle of a func body"
+foreach runtime [get_runtime_list] {
+ if {$runtime eq ""} { set runtime "kernel" }
+ set test_name "$test: $subtest1 ($runtime)"
+
+ set cmd "stap --runtime=$runtime '$srcdir/$subdir/${test}_1.stp'"
+ send_log "executing: $cmd\n"
+ set pipe [open "| sh -c {$cmd}" r]
+ set out [read $pipe]
+ set failed 0
+ if {[catch {close $pipe} stderr] != 0} { set failed 1 }
+
+ set exp_out "enter f\n"
+ regsub -all -- {\n} $exp_out {\n} escaped_exp_out
+ if {$out eq $exp_out} {
+ pass "${test_name}: stdout matches \"$escaped_exp_out\""
+ } else {
+ fail "${test_name}: stdout fails to match \"$escaped_exp_out\": got \"$out\""
+ }
+
+ if {$failed} {
+ fail "${test_name}: exit code not zero"
+ } else {
+ pass "${test_name}: exit code is zero"
+ }
+ if {$stderr ne ""} {
+ send_log "stderr:\n$stderr"
+ }
+}
+
+# --- TEST 2 ---
+
+set subtest2 "TEST 2: quit() in the middle of a func body in a deeper func call chain"
+foreach runtime [get_runtime_list] {
+ if {$runtime eq ""} { set runtime "kernel" }
+ set test_name "$test: $subtest2 ($runtime)"
+
+ set cmd "stap --runtime=$runtime '$srcdir/$subdir/${test}_2.stp'"
+ send_log "executing: $cmd\n"
+ set pipe [open "| sh -c {$cmd}" r]
+ set out [read $pipe]
+ set failed 0
+ if {[catch {close $pipe} stderr] != 0} { set failed 1 }
+
+ set exp_out "enter g\nenter f\n"
+ regsub -all -- {\n} $exp_out {\n} escaped_exp_out
+ if {$out eq $exp_out} {
+ pass "${test_name}: stdout matches \"$escaped_exp_out\""
+ } else {
+ fail "${test_name}: stdout fails to match \"$escaped_exp_out\": got \"$out\""
+ }
+
+ if {$failed} {
+ fail "${test_name}: exit code not zero"
+ } else {
+ pass "${test_name}: exit code is zero"
+ }
+ if {$stderr ne ""} {
+ send_log "stderr:\n$stderr"
+ }
+}
+
+# --- TEST 3 ---
+
+set subtest3 "TEST 3: quit() in the middle of a probe handler body"
+foreach runtime [get_runtime_list] {
+ if {$runtime eq ""} { set runtime "kernel" }
+ set test_name "$test: $subtest3 ($runtime)"
+
+ set cmd "stap --runtime=$runtime '$srcdir/$subdir/${test}_3.stp'"
+ send_log "executing: $cmd\n"
+ set pipe [open "| sh -c {$cmd}" r]
+ set out [read $pipe]
+ set failed 0
+ if {[catch {close $pipe} stderr] != 0} { set failed 1 }
+
+ set exp_out "enter probe\n"
+ regsub -all -- {\n} $exp_out {\n} escaped_exp_out
+ if {$out eq $exp_out} {
+ pass "${test_name}: stdout matches \"$escaped_exp_out\""
+ } else {
+ fail "${test_name}: stdout fails to match \"$escaped_exp_out\": got \"$out\""
+ }
+
+ if {$failed} {
+ fail "${test_name}: exit code not zero"
+ } else {
+ pass "${test_name}: exit code is zero"
+ }
+ if {$stderr ne ""} {
+ send_log "stderr:\n$stderr"
+ }
+}
diff --git a/testsuite/systemtap.base/quit_1.stp b/testsuite/systemtap.base/quit_1.stp
new file mode 100644
index 000000000..a60b3df1c
--- /dev/null
+++ b/testsuite/systemtap.base/quit_1.stp
@@ -0,0 +1,11 @@
+function f() {
+ println("enter f");
+ quit();
+ println("leave f");
+}
+
+probe begin {
+ f();
+ printf("quit\n");
+ quit();
+}
diff --git a/testsuite/systemtap.base/quit_2.stp b/testsuite/systemtap.base/quit_2.stp
new file mode 100644
index 000000000..2bc739f58
--- /dev/null
+++ b/testsuite/systemtap.base/quit_2.stp
@@ -0,0 +1,17 @@
+function f() {
+ println("enter f");
+ quit();
+ println("leave f");
+}
+
+function g() {
+ println("enter g");
+ f();
+ println("leave g");
+}
+
+probe begin {
+ g();
+ printf("quit\n");
+ quit();
+}
diff --git a/testsuite/systemtap.base/quit_3.stp b/testsuite/systemtap.base/quit_3.stp
new file mode 100644
index 000000000..a3b796f41
--- /dev/null
+++ b/testsuite/systemtap.base/quit_3.stp
@@ -0,0 +1,5 @@
+probe begin {
+ println("enter probe");
+ quit();
+ println("leave probe");
+}
diff --git a/translate.cxx b/translate.cxx
index c7e7aa53f..24e3167b7 100644
--- a/translate.cxx
+++ b/translate.cxx
@@ -5732,7 +5732,7 @@ c_unparser::visit_functioncall (functioncall* e)
// call function
o->newline() << c_funcname (r->name) << " (c);";
- o->newline() << "if (unlikely(c->last_error)) goto out;";
+ o->newline() << "if (unlikely(c->last_error || _stp_quitting)) goto out;";
if (!already_checked_action_count && !session->suppress_time_limits
&& !session->unoptimized)
@@ -6069,7 +6069,7 @@ c_unparser::visit_print_format (print_format* e)
}
o->line() << ");";
o->newline(-1) << "#endif // STP_LEGACY_PRINT";
- o->newline() << "if (unlikely(c->last_error)) goto out;";
+ o->newline() << "if (unlikely(c->last_error || _stp_quitting)) goto out;";
o->newline() << res.value() << ";";
}
}
--
2.11.0.295.gd7dffce