erts: Fix SEGV when killing process during yielding re:run

Adjust pointer from pcre2_match_data to allocated RestartContext
at first yield, don't wait until first trap call.

Author: sverker

erts/emulator/beam/erl_bif_re.c

@@ -1477,6 +1477,7 @@ re_run(Process *p, Eterm arg1, Eterm arg2, Eterm arg3, int first)
             Eterm *hp;
             BUMP_REDS(p, reds_consumed);
             sys_memcpy(restartp,&restart,sizeof(RestartContext));
+            pcre2_set_restart_data(restart.match_data, &restartp->restart_data);
             ERTS_VBUMP_ALL_REDS(p);
             hp = HAlloc(p, ERTS_MAGIC_REF_THING_SIZE);
             magic_ref = erts_mk_magic_ref(&hp, &MSO(p), mbp);
@@ -1592,7 +1593,6 @@ static BIF_RETTYPE re_match_trap(BIF_ALIST_3)
     restartp = (RestartContext *) ERTS_MAGIC_BIN_DATA(mbp);
     loop_limit = MIN(reds_initial * LOOP_FACTOR, max_loop_limit);
     pcre2_set_loops_left(restartp->match_data, loop_limit);
-    pcre2_set_restart_data(restartp->match_data, &restartp->restart_data);
     pcre2_set_restart_flags(restartp->match_data,  0);
 
     rc = pcre2_match(NULL, NULL, 0, 0, 0, restartp->match_data, NULL);

lib/stdlib/test/re_SUITE.erl

@@ -35,6 +35,7 @@
 	 match_limit/1,sub_binaries/1,copt/1,global_unicode_validation/1,
          yield_on_subject_validation/1, bad_utf8_subject/1,
          error_info/1, subject_is_sub_binary/1, pattern_is_sub_binary/1,
+         kill_yielding/1,
 
          last_test/1]).
 
@@ -58,6 +59,7 @@ all() ->
      match_limit, sub_binaries, re_version, global_unicode_validation,
      yield_on_subject_validation, bad_utf8_subject,
      error_info, subject_is_sub_binary, pattern_is_sub_binary,
+     kill_yielding,
 
      last_test].
 
@@ -1163,6 +1165,30 @@ subject_is_sub_binary(Config) when is_list(Config) ->
         ok
     end.
 
+%% OTP-19888: Verify that process can handle being killed while yielding
+%% inside re:run without beam crash or memory leak.
+kill_yielding(Config) when is_list(Config) ->
+    Subject = binary:copy(~"hejsan", 100_000),
+    DoIt = fun(RE) ->
+                   {Pid, MRef} = spawn_monitor(fun() ->
+                                                       re:run(Subject, RE)
+                                               end),
+                   erlang:yield(),
+                   exit(Pid, kill),
+                   {'DOWN',MRef,process,Pid,killed} = receive_any()
+           end,
+
+    RE_string = ~B"\w+\d",
+    {ok, RE_compiled} = re:compile(RE_string, []),
+    DoIt(RE_string),
+    DoIt(RE_compiled),
+    ok.
+
+receive_any() ->
+    receive M -> M
+    after 1000 -> timeout
+    end.
+
 last_test(Config) when is_list(Config) ->
     erts_debug:set_internal_state(available_internal_state, true),
     Res = case erts_debug:get_internal_state(re_yield_coverage) of