[Tarantool-patches] [PATCH luajit v4 3/3] Follow-up fix for stack overflow handling cleanup.

[Maxim Kokryashkin]

From: Mike Pall <mike>

(cherry-picked from commit aa6b15c1a8922848bd6f596ba384824ca3fe0f5f)

The stack overflow error is thrown in `lj_state_growstack` only
if the coroutine status is `OK`, however, stack overflow can
happen on a yielded coroutine too. This patch fixes the condition
for status, so now the error thrown on yielded coroutines too.

Maxim Kokryashkin:
* added the description and the test for the patch

Part of tarantool/tarantool#9145
---
 src/lj_state.c                                |  2 +-
 .../lj-962-premature-stack-overflow.test.c    | 32 +++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/lj_state.c b/src/lj_state.c
index d8a5134c..01d4901a 100644
--- a/src/lj_state.c
+++ b/src/lj_state.c
@@ -126,7 +126,7 @@ void LJ_FASTCALL lj_state_growstack(lua_State *L, MSize need)
     if (L->stacksize > LJ_STACK_MAXEX)
       lj_err_throw(L, LUA_ERRERR);  /* Does not invoke an error handler. */
     /* 1. We are _at_ the limit after the last growth. */
-    if (!L->status) {  /* 2. Throw 'stack overflow'. */
+    if (L->status < LUA_ERRRUN) {  /* 2. Throw 'stack overflow'. */
       L->status = LUA_ERRRUN;  /* Prevent ending here again for pushed msg. */
       lj_err_msg(L, LJ_ERR_STKOV);  /* May invoke an error handler. */
     }
diff --git a/test/tarantool-c-tests/lj-962-premature-stack-overflow.test.c b/test/tarantool-c-tests/lj-962-premature-stack-overflow.test.c
index 12cb9004..3b006805 100644
--- a/test/tarantool-c-tests/lj-962-premature-stack-overflow.test.c
+++ b/test/tarantool-c-tests/lj-962-premature-stack-overflow.test.c
@@ -7,7 +7,9 @@
 /*
  * XXX: The "lj_obj.h" header is included to calculate the
  * number of stack slots used from the bottom of the stack.
+ * XXX: The "lj_arch.h" header is included for the skipcond.
  */
+#include "lj_arch.h"
 #include "lj_obj.h"
 
 static int cur_slots = -1;
@@ -24,6 +26,22 @@ static int fill_stack(lua_State *L)
 	return 0;
 }
 
+#if !LJ_NO_UNWIND
+static int immediate_yield(lua_State *L)
+{
+	return lua_yield(L, 0);
+}
+
+static int overflow_suspended_coro(lua_State *L)
+{
+	lua_State *newL = lua_newthread(L);
+	lua_pushcfunction(newL, immediate_yield);
+	lua_resume(newL, 0);
+	fill_stack(newL);
+	return 0;
+}
+#endif
+
 static int premature_stackoverflow(void *test_state)
 {
 	lua_State *L = test_state;
@@ -50,12 +68,26 @@ static int stackoverflow_during_stackoverflow(void *test_state)
 	return TEST_EXIT_SUCCESS;
 }
 
+static int stackoverflow_on_suspended_coro(void *test_state)
+{
+#if LJ_NO_UNWIND
+	UNUSED(test_state);
+	return skip("Internal unwinding can't catch this exception");
+#else
+	lua_State *L = test_state;
+	int status = lua_cpcall(L, overflow_suspended_coro, NULL);
+	assert_true(status == LUA_ERRRUN);
+	return TEST_EXIT_SUCCESS;
+#endif
+}
+
 int main(void)
 {
 	lua_State *L = utils_lua_init();
 	const struct test_unit tgroup[] = {
 		test_unit_def(premature_stackoverflow),
 		test_unit_def(stackoverflow_during_stackoverflow),
+		test_unit_def(stackoverflow_on_suspended_coro),
 	};
 	const int test_result = test_run_group(tgroup, L);
 	utils_lua_close(L);
-- 
2.43.0