func-tests: add gdb backtrace dumping

tests-extra/README

@@ -7,6 +7,15 @@ dnssec-signzone
 dnssec-verify
 Bind 9.9
 lsof
+(gdb)
 
-Ubuntu - disable apparmor protection for system Bind:
-sudo apparmor_parser -R /etc/apparmor.d/usr.sbin.named
\ No newline at end of file
+Ubuntu:
+-------
+Disable apparmor protection for system Bind:
+# sudo apparmor_parser -R /etc/apparmor.d/usr.sbin.named
+
+Allow ptrace:
+echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope
+or
+/etc/sysctl.d/10-ptrace.conf
+kernel.yama.ptrace_scope = 0

tests-extra/tools/dnstest/params.py

@@ -34,7 +34,12 @@ debug = False
 # KNOT_TEST_VALGRIND - valgrind binary if defined.
 valgrind_bin = get_binary("KNOT_TEST_VALGRIND", "valgrind")
 # KNOT_TEST_VALGRIND_FLAGS - valgrind flags.
-valgrind_flags = get_param("KNOT_TEST_VALGRIND_FLAGS", "--leak-check=full")
+valgrind_flags = get_param("KNOT_TEST_VALGRIND_FLAGS",
+                           "--leak-check=full --vgdb=yes")
+# KNOT_TEST_GDB - gdb binary.
+gdb_bin = get_binary("KNOT_TEST_GDB", "gdb")
+# KNOT_TEST_VGDB - vgdb binary.
+vgdb_bin = get_binary("KNOT_TEST_VGDB", "vgdb")
 # KNOT_TEST_KNOT - Knot binary.
 knot_bin = get_binary("KNOT_TEST_KNOT", "../src/knotd")
 # KNOT_TEST_KNOTC - Knot control binary.

tests-extra/tools/dnstest/server.py

@@ -295,6 +295,24 @@ class Server(object):
         detail_log(SEP)
         f.close()
 
+    def backtrace(self):
+        if self.valgrind:
+            check_log("BACKTRACE %s" % self.name)
+
+            try:
+                out = open(self.dir + "/gdb.out", mode="a")
+                err = open(self.dir + "/gdb.err", mode="a")
+
+                check_call([params.gdb_bin, "-ex", "set confirm off", "-ex",
+                            "target remote | %s --pid=%s" %
+                            (params.vgdb_bin, self.proc.pid),
+                            "-ex", "bt full", "-ex", "q", self.daemon_bin],
+                           stdout=out, stderr=err)
+            except:
+                detail_log("!Failed to get backtrace")
+
+            detail_log(SEP)
+
     def stop(self, check=True):
         if self.proc:
             try:
@@ -303,6 +321,7 @@ class Server(object):
             except ProcessLookupError:
                 pass
             except:
+                self.backtrace()
                 check_log("WARNING: KILLING %s" % self.name)
                 detail_log(SEP)
                 self.proc.kill()
@@ -486,6 +505,7 @@ class Server(object):
                     break
             time.sleep(2)
         else:
+            self.backtrace()
             raise Exception("Can't get %s SOA%s from %s." % (zone.name,
                             ">%i" % serial if serial else "", self.name))
 

tests-extra/tools/dnstest/test.py

@@ -105,7 +105,7 @@ class Test(object):
 
         if params.valgrind_bin and \
            (valgrind or (valgrind == None and server == "knot")):
-            srv.valgrind = [params.valgrind_bin, params.valgrind_flags]
+            srv.valgrind = [params.valgrind_bin] + params.valgrind_flags.split()
 
         srv.data_dir = self.data_dir