Initialize the stack bounds prior to checking the cookie

Without this change reading of the cookie value calls into __asan_loadN
which then tries to use SP, but SP is not yet initialzed, so the
asan code itself trigger a STACK_OVERFLOW_CHECK error.

This fixes the asan.test_stack test which was broken by emscripten-core#24314 but went
unnoticed because we don't run all the asan tests in emscripten CI.

Author: sbc100

.circleci/config.yml

@@ -539,6 +539,7 @@ jobs:
           title: "asan+lsan"
           test_targets: "
             asan.test_stat
+            asan.test_stack
             asan.test_float_builtins
             asan.test_embind*
             asan.test_abort_on_exceptions

src/postamble_minimal.js

@@ -60,10 +60,10 @@ function initRuntime(wasmExports) {
 
 #if STACK_OVERFLOW_CHECK
   _emscripten_stack_init();
-  writeStackCookie();
 #if STACK_OVERFLOW_CHECK >= 2
   setStackLimits();
 #endif
+  writeStackCookie();
 #endif
 
 #if PTHREADS

src/preamble.js

@@ -199,14 +199,14 @@ function initRuntime() {
   if (ENVIRONMENT_IS_PTHREAD) return startWorker(Module);
 #endif
 
-#if STACK_OVERFLOW_CHECK
-  checkStackCookie();
-#endif
-
 #if STACK_OVERFLOW_CHECK >= 2
   setStackLimits();
 #endif
 
+#if STACK_OVERFLOW_CHECK
+  checkStackCookie();
+#endif
+
 #if RELOCATABLE
   callRuntimeCallbacks(__RELOC_FUNCS__);
 #endif

test/core/test_stack.c

@@ -5,7 +5,9 @@
  * found in the LICENSE file.
  */
 
+#include <assert.h>
 #include <stdio.h>
+
 int test(int i) {
   int x = 10;
   int ret = (long)&x;  // both for the number, and forces x to not be nativized
@@ -17,11 +19,15 @@ int test(int i) {
   }
   return ret;
 }
+
 int main(int argc, char **argv) {
   // We should get the same value for the first and last - stack has unwound
+  printf("in main\n");
   int x1 = test(argc - 2);
   int x2 = test(100);
   int x3 = test((argc - 2) / 4);
+  assert(x2 != x1);
+  assert(x3 == x1);
   printf("*%d,%d*\n", x3 - x1, x2 != x1);
   return 0;
 }