Merge pull request #1294 from tannewt/stack_check4.0.0-alpha.4

Add stack validity check and raise an error when it happens.

1 files changed, 14 insertions, 0 deletions

diff --git a/supervisor/shared/stack.c b/supervisor/shared/stack.c
index 6b74742eb..71e239c0a 100755
--- a/supervisor/shared/stack.c
+++ b/supervisor/shared/stack.c
@@ -27,7 +27,9 @@
 #include "stack.h"
 
 #include "py/mpconfig.h"
+#include "py/runtime.h"
 #include "supervisor/cpu.h"
+#include "supervisor/shared/safe_mode.h"
 
 extern uint32_t _estack;
 
@@ -50,6 +52,17 @@ void allocate_stack(void) {
     } else {
         current_stack_size = next_stack_size;
     }
+    *stack_alloc->ptr = STACK_CANARY_VALUE;
+}
+
+inline bool stack_ok(void) {
+    return *stack_alloc->ptr == STACK_CANARY_VALUE;
+}
+
+inline void assert_heap_ok(void) {
+    if (!stack_ok()) {
+        reset_into_safe_mode(HEAP_OVERWRITTEN);
+    }
 }
 
 void stack_init(void) {
@@ -58,6 +71,7 @@ void stack_init(void) {
 
 void stack_resize(void) {
     if (next_stack_size == current_stack_size) {
+        *stack_alloc->ptr = STACK_CANARY_VALUE;
         return;
     }
     free_memory(stack_alloc);