From 48d3bdddbaeabed5fb6a97bfbe65e250d1383a9c Mon Sep 17 00:00:00 2001
From: KJ Tsanaktsidis <kj@kjtsanaktsidis.id.au>
Date: Sat, 24 Feb 2024 19:31:27 +1100
Subject: [PATCH] Move asan_fake_stack_handle to EC, not thread

It's really a property of the EC; each fiber (which has its own EC) also
has its own asan_fake_stack_handle.

[Bug #20310]
---
 gc.c             | 2 +-
 thread.c         | 3 ---
 thread_pthread.c | 1 +
 vm_core.h        | 9 ++++-----
 4 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/gc.c b/gc.c
index eaa98928ff..07c0735a44 100644
--- a/gc.c
+++ b/gc.c
@@ -6410,7 +6410,7 @@ gc_mark_machine_stack_location_maybe(rb_objspace_t *objspace, VALUE obj)
     void *fake_frame_start;
     void *fake_frame_end;
     bool is_fake_frame = asan_get_fake_stack_extents(
-        ec->thread_ptr->asan_fake_stack_handle, obj,
+        ec->machine.asan_fake_stack_handle, obj,
         ec->machine.stack_start, ec->machine.stack_end,
         &fake_frame_start, &fake_frame_end
     );
diff --git a/thread.c b/thread.c
index b8dd862634..e672172a4d 100644
--- a/thread.c
+++ b/thread.c
@@ -527,9 +527,6 @@ void
 ruby_thread_init_stack(rb_thread_t *th, void *local_in_parent_frame)
 {
     native_thread_init_stack(th, local_in_parent_frame);
-#ifdef RUBY_ASAN_ENABLED
-    th->asan_fake_stack_handle = asan_get_thread_fake_stack_handle();
-#endif
 }
 
 const VALUE *
diff --git a/thread_pthread.c b/thread_pthread.c
index fb446eee82..cdaf6f240c 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -2081,6 +2081,7 @@ native_thread_init_stack(rb_thread_t *th, void *local_in_parent_frame)
     rb_nativethread_id_t curr = pthread_self();
 #ifdef RUBY_ASAN_ENABLED
     local_in_parent_frame = asan_get_real_stack_addr(local_in_parent_frame);
+    th->ec->machine.asan_fake_stack_handle = asan_get_thread_fake_stack_handle();
 #endif
 
     if (!native_main_thread.id) {
diff --git a/vm_core.h b/vm_core.h
index da1f568b66..805df18616 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -1044,6 +1044,10 @@ struct rb_execution_context_struct {
         VALUE *stack_end;
         size_t stack_maxsize;
         RUBY_ALIGNAS(SIZEOF_VALUE) jmp_buf regs;
+
+#ifdef RUBY_ASAN_ENABLED
+        void *asan_fake_stack_handle;
+#endif
     } machine;
 };
 
@@ -1164,11 +1168,6 @@ typedef struct rb_thread_struct {
     void **specific_storage;
 
     struct rb_ext_config ext_config;
-
-#ifdef RUBY_ASAN_ENABLED
-    void *asan_fake_stack_handle;
-#endif
-
 } rb_thread_t;
 
 static inline unsigned int