From 4189a1c7294fefb228299383a0a109f4ba305ff1 Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Wed, 11 Sep 2024 14:31:26 +0300
Subject: [PATCH] LibC: Make _init and _fini weak symbols

These seem to be missing sometimes when making shared executables
---
 userspace/libraries/LibC/arch/i686/crt0.S   | 6 +++++-
 userspace/libraries/LibC/arch/x86_64/crt0.S | 6 +++++-
 userspace/libraries/LibC/stdlib.cpp         | 4 ++--
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/userspace/libraries/LibC/arch/i686/crt0.S b/userspace/libraries/LibC/arch/i686/crt0.S
index 50d635ff..f50cdfb4 100644
--- a/userspace/libraries/LibC/arch/i686/crt0.S
+++ b/userspace/libraries/LibC/arch/i686/crt0.S
@@ -19,7 +19,11 @@ _start:
 	call _init_libc
 
 	# call global constructors
-	call _init
+	movl $_init, %eax
+	testl %eax, %eax
+	jz 1f
+	call *%eax
+ 1:
 
 	movl $__init_array_start, %ebx
 	jmp 2f
diff --git a/userspace/libraries/LibC/arch/x86_64/crt0.S b/userspace/libraries/LibC/arch/x86_64/crt0.S
index 46d83cdc..b5b543c9 100644
--- a/userspace/libraries/LibC/arch/x86_64/crt0.S
+++ b/userspace/libraries/LibC/arch/x86_64/crt0.S
@@ -20,7 +20,11 @@ _start:
 	call _init_libc
 
 	# call global constructors
-	call _init
+	movq $_init, %rax
+	testq %rax, %rax
+	jz 1f
+	call *%rax
+ 1:
 
 	movq $__init_array_start, %rbx
 	jmp 2f
diff --git a/userspace/libraries/LibC/stdlib.cpp b/userspace/libraries/LibC/stdlib.cpp
index 3be7c717..18773023 100644
--- a/userspace/libraries/LibC/stdlib.cpp
+++ b/userspace/libraries/LibC/stdlib.cpp
@@ -16,7 +16,7 @@
 
 extern "C" char** environ;
 
-extern "C" void _fini();
+extern "C" __attribute__((weak)) void _fini();
 
 static void (*at_exit_funcs[64])();
 static uint32_t at_exit_funcs_count = 0;
@@ -34,7 +34,7 @@ void exit(int status)
 		at_exit_funcs[i - 1]();
 	fflush(nullptr);
 	__cxa_finalize(nullptr);
-	_fini();
+	if (_fini) _fini();
 	_exit(status);
 	ASSERT_NOT_REACHED();
 }