Merge 8.6

1 files changed, 38 insertions, 2 deletions

diff --git a/generic/tclBasic.c b/generic/tclBasic.c
index 318374e..4187462 100644
--- a/generic/tclBasic.c
+++ b/generic/tclBasic.c
@@ -64,6 +64,41 @@
 #endif /* !TCL_FPCLASSIFY_MODE */
 
 
+/*
+ * Bug 7371b6270b: to check C call stack depth, prefer an approach which is
+ * compatible with AddressSanitizer (ASan) use-after-return detection.
+ */
+
+#if defined(HAVE_INTRIN_H)
+#include <intrin.h> /* for _AddressOfReturnAddress() */
+#endif
+
+/*
+ * As suggested by
+ * https://clang.llvm.org/docs/LanguageExtensions.html#has-builtin
+ */
+#ifndef __has_builtin
+#define __has_builtin(x) 0 /* for non-clang compilers */
+#endif
+
+void *
+TclGetCStackPtr(void)
+{
+#if defined(HAVE_INTRIN_H)
+  return _AddressOfReturnAddress();
+#elif __GNUC__ || __has_builtin(__builtin_frame_address)
+  return __builtin_frame_address(0);
+#else
+  ptrdiff_t unused = 0;
+  /*
+   * LLVM recommends using volatile:
+   * https://github.com/llvm/llvm-project/blob/llvmorg-10.0.0-rc1/clang/lib/Basic/Stack.cpp#L31
+   */
+  ptrdiff_t *volatile stackLevel = &unused;
+  return (void *)stackLevel;
+#endif
+}
+
 #define INTERP_STACK_INITIAL_SIZE 2000
 #define CORO_STACK_INITIAL_SIZE    200
 
@@ -9726,6 +9761,7 @@ TclNRCoroutineActivateCallback(
     TCL_UNUSED(int) /*result*/)
 {
     CoroutineData *corPtr = (CoroutineData *)data[0];
+    void *stackLevel = TclGetCStackPtr();
 
     if (!corPtr->stackLevel) {
         /*
@@ -9742,7 +9778,7 @@ TclNRCoroutineActivateCallback(
          * the interp's environment to make it suitable to run this coroutine.
          */
 
-        corPtr->stackLevel = &corPtr;
+        corPtr->stackLevel = stackLevel;
         Tcl_Size numLevels = corPtr->auxNumLevels;
         corPtr->auxNumLevels = iPtr->numLevels;
 
@@ -9756,7 +9792,7 @@ TclNRCoroutineActivateCallback(
          * Coroutine is active: yield
          */
 
-        if (corPtr->stackLevel != &corPtr) {
+        if (corPtr->stackLevel != stackLevel) {
 	    NRE_callback *runPtr;
 
 	    iPtr->execEnvPtr = corPtr->callerEEPtr;