From 213458b7b0479c14adc4b0c256a657923ae7be11 Mon Sep 17 00:00:00 2001
From: Gabriel Baraldi <baraldigabriel@gmail.com>
Date: Sat, 29 Apr 2023 20:21:26 -0300
Subject: [PATCH 1/3] Fix dyld lock not getting unlocked on invalid threads.
 (#49446)

---
 src/signals-mach.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/signals-mach.c b/src/signals-mach.c
index dbd303d868e8e..dee1bb393ee98 100644
--- a/src/signals-mach.c
+++ b/src/signals-mach.c
@@ -621,8 +621,7 @@ void *mach_profile_listener(void *arg)
             if (_dyld_atfork_prepare != NULL && _dyld_atfork_parent != NULL)
                 _dyld_atfork_prepare(); // briefly acquire the dlsym lock
             host_thread_state_t state;
-            if (!jl_thread_suspend_and_get_state2(i, &state))
-                continue;
+            int valid_thread = jl_thread_suspend_and_get_state2(i, &state);
             unw_context_t *uc = (unw_context_t*)&state;
             if (_dyld_atfork_prepare != NULL && _dyld_atfork_parent != NULL)
                 _dyld_atfork_parent(); // quickly release the dlsym lock

From f7d20c6a165547ede5ae512801d25ee19263a125 Mon Sep 17 00:00:00 2001
From: Jameson Nash <vtjnash@gmail.com>
Date: Thu, 11 May 2023 13:29:07 -0400
Subject: [PATCH 2/3] macOS: avoid deadlock inside dyld4 deadlock workaround
 (#49740)

Extend the fix for #43578 (2939272af2ef3fe9d8921f7ed0a6500e31a550c9) to
cover the deadlock bug present internally in dyld4 inside the function
we use to avoid the previous deadlock issue.

Fix #49733
---
 src/signals-mach.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/signals-mach.c b/src/signals-mach.c
index dee1bb393ee98..a0941d1b59f97 100644
--- a/src/signals-mach.c
+++ b/src/signals-mach.c
@@ -36,6 +36,9 @@ extern int _keymgr_set_lockmode_processwide_ptr(unsigned int key, unsigned int m
 extern void _dyld_atfork_prepare(void) __attribute__((weak_import));
 extern void _dyld_atfork_parent(void) __attribute__((weak_import));
 //extern void _dyld_fork_child(void) __attribute__((weak_import));
+extern void _dyld_dlopen_atfork_prepare(void) __attribute__((weak_import));
+extern void _dyld_dlopen_atfork_parent(void) __attribute__((weak_import));
+//extern void _dyld_dlopen_atfork_child(void) __attribute__((weak_import));
 
 static void attach_exception_port(thread_port_t thread, int segv_only);
 
@@ -564,7 +567,12 @@ static int jl_lock_profile_mach(int dlsymlock)
     // workaround for old keymgr bugs
     void *unused = NULL;
     int keymgr_locked = _keymgr_get_and_lock_processwide_ptr_2(KEYMGR_GCC3_DW2_OBJ_LIST, &unused) == 0;
-    // workaround for new dlsym4 bugs (API and bugs introduced in macOS 12.1)
+    // workaround for new dlsym4 bugs in the workaround for dlsym bugs: _dyld_atfork_prepare
+    // acquires its locks in the wrong order, but fortunately we happen to able to guard it
+    // with this call to force it to prevent that TSAN violation from causing a deadlock
+    if (dlsymlock && _dyld_dlopen_atfork_prepare != NULL && _dyld_dlopen_atfork_parent != NULL)
+        _dyld_dlopen_atfork_prepare();
+    // workaround for new dlsym4 bugs (API and bugs introduced circa macOS 12.1)
     if (dlsymlock && _dyld_atfork_prepare != NULL && _dyld_atfork_parent != NULL)
         _dyld_atfork_prepare();
     return keymgr_locked;
@@ -572,8 +580,10 @@ static int jl_lock_profile_mach(int dlsymlock)
 
 static void jl_unlock_profile_mach(int dlsymlock, int keymgr_locked)
 {
-    if (dlsymlock && _dyld_atfork_prepare != NULL && _dyld_atfork_parent != NULL) \
-        _dyld_atfork_parent(); \
+    if (dlsymlock && _dyld_atfork_prepare != NULL && _dyld_atfork_parent != NULL)
+        _dyld_atfork_parent();
+    if (dlsymlock && _dyld_dlopen_atfork_prepare != NULL && _dyld_dlopen_atfork_parent != NULL)
+        _dyld_dlopen_atfork_parent();
     if (keymgr_locked)
         _keymgr_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST);
     jl_unlock_profile();
@@ -618,6 +628,8 @@ void *mach_profile_listener(void *arg)
                 break;
             }
 
+            if (_dyld_dlopen_atfork_prepare != NULL && _dyld_dlopen_atfork_parent != NULL)
+                _dyld_dlopen_atfork_prepare();
             if (_dyld_atfork_prepare != NULL && _dyld_atfork_parent != NULL)
                 _dyld_atfork_prepare(); // briefly acquire the dlsym lock
             host_thread_state_t state;
@@ -625,7 +637,10 @@ void *mach_profile_listener(void *arg)
             unw_context_t *uc = (unw_context_t*)&state;
             if (_dyld_atfork_prepare != NULL && _dyld_atfork_parent != NULL)
                 _dyld_atfork_parent(); // quickly release the dlsym lock
-
+            if (_dyld_dlopen_atfork_prepare != NULL && _dyld_dlopen_atfork_parent != NULL)
+                _dyld_dlopen_atfork_parent();
+            if (!valid_thread)
+                continue;
             if (running) {
 #ifdef LLVMLIBUNWIND
                 /*

From 007bcef42a2d0fc194376eca50814371cb5e71ae Mon Sep 17 00:00:00 2001
From: Jameson Nash <vtjnash@gmail.com>
Date: Fri, 12 May 2023 10:02:12 -0400
Subject: [PATCH 3/3] fix build failure with dyld4 deadlock workaround (#49776)

Accidentally missed in #49740
Fixes #49773
---
 src/mach_dyld_atfork.tbd | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/mach_dyld_atfork.tbd b/src/mach_dyld_atfork.tbd
index 9a5d18099dbcf..c2cda4417ec38 100644
--- a/src/mach_dyld_atfork.tbd
+++ b/src/mach_dyld_atfork.tbd
@@ -21,5 +21,6 @@ install-name:    '/usr/lib/libSystem.B.dylib'
 exports:
   - targets:         [ arm64-macos, arm64e-macos, x86_64-macos, x86_64-maccatalyst,
                        arm64-maccatalyst, arm64e-maccatalyst ]
-    symbols:         [ __dyld_atfork_parent, __dyld_atfork_prepare ]
+    symbols:         [ __dyld_atfork_parent, __dyld_atfork_prepare,
+                      __dyld_dlopen_atfork_parent, __dyld_dlopen_atfork_prepare ]
 ...