Revert "Make stack bounds detection work with ASAN"

This reverts commit 6185cfdf38.

internal/sanitizers.h

@@ -64,8 +64,6 @@
 # define __asan_poison_memory_region(x, y)
 # define __asan_unpoison_memory_region(x, y)
 # define __asan_region_is_poisoned(x, y) 0
-# define __asan_get_current_fake_stack() NULL
-# define __asan_addr_is_in_fake_stack(fake_stack, slot, start, end) NULL
 #endif
 
 #if !__has_feature(memory_sanitizer)
@@ -185,28 +183,4 @@ asan_unpoison_object(VALUE obj, bool newobj_p)
     asan_unpoison_memory_region(ptr, SIZEOF_VALUE, newobj_p);
 }
 
-
-/*!
- * Checks if the given pointer is on an ASAN fake stack. If so, it returns the
- * address this variable has on the real frame; if not, it returns the origin
- * address unmodified.
- *
- * n.b. - _dereferencing_ the returned address is meaningless and should not
- * be done; even though ASAN reserves space for the variable in both the real and
- * fake stacks, the _value_ of that variable is only in the fake stack.
- *
- * n.b. - this only works for addresses passed in from local variables on the same
- * thread, because the ASAN fake stacks are threadlocal.
- *
- * \param[in] slot  the address of some local variable
- * \retval          a pointer to something from that frame on the _real_ machine stack
- */
-static inline void *
-asan_get_real_stack_addr(void* slot)
-{
-    VALUE *addr;
-    addr = __asan_addr_is_in_fake_stack(__asan_get_current_fake_stack(), slot, NULL, NULL);
-    return addr ? addr : slot;
-}
-
 #endif /* INTERNAL_SANITIZERS_H */

thread_pthread.c

@@ -12,7 +12,6 @@
 #ifdef THREAD_SYSTEM_DEPENDENT_IMPLEMENTATION
 
 #include "internal/gc.h"
-#include "internal/sanitizers.h"
 #include "rjit.h"
 
 #ifdef HAVE_SYS_RESOURCE_H
@@ -1968,7 +1967,6 @@ void
 ruby_init_stack(volatile void *addr)
 {
     native_main_thread.id = pthread_self();
-    addr = asan_get_real_stack_addr((void *)addr);
 
 #if MAINSTACKADDR_AVAILABLE
     if (native_main_thread.stack_maxsize) return;
@@ -2067,7 +2065,7 @@ native_thread_init_stack(rb_thread_t *th, void *local_in_parent_frame)
 
             if (get_stack(&start, &size) == 0) {
                 uintptr_t diff = (uintptr_t)start - (uintptr_t)local_in_parent_frame;
-                th->ec->machine.stack_start = asan_get_real_stack_addr(local_in_parent_frame);
+                th->ec->machine.stack_start = (uintptr_t)local_in_parent_frame;
                 th->ec->machine.stack_maxsize = size - diff;
             }
         }
@@ -2194,10 +2192,12 @@ call_thread_start_func_2(rb_thread_t *th)
        on a new thread, and replacing that data on fiber-switch would break it (see
        bug #13887) */
     VALUE stack_start = 0;
-    VALUE *stack_start_addr = asan_get_real_stack_addr(&stack_start);
+    VALUE *stack_start_addr = &stack_start;
-
     native_thread_init_stack(th, stack_start_addr);
     thread_start_func_2(th, th->ec->machine.stack_start);
+
+    /* Ensure that stack_start really was spilled to the stack */
+    RB_GC_GUARD(stack_start)
 }
 
 static void *

thread_win32.c

@@ -11,7 +11,6 @@
 
 #ifdef THREAD_SYSTEM_DEPENDENT_IMPLEMENTATION
 
-#include "internal/sanitizers.h"
 #include <process.h>
 
 #define TIME_QUANTUM_USEC (10 * 1000)
@@ -597,7 +596,7 @@ COMPILER_WARNING_IGNORED(-Wmaybe-uninitialized)
 static inline SIZE_T
 query_memory_basic_info(PMEMORY_BASIC_INFORMATION mi, void *local_in_parent_frame)
 {
-    return VirtualQuery(asan_get_real_stack_addr(local_in_parent_frame), mi, sizeof(*mi));
+    return VirtualQuery(local_in_parent_frame, mi, sizeof(*mi));
 }
 COMPILER_WARNING_POP