From 0bb44d7b758317cabeb7972a2aff833da6e6e408 Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Wed, 4 Sep 2024 21:16:04 +0300
Subject: [PATCH] LibC: Fix errno to work with shared libraries

---
 userspace/libraries/LibC/CMakeLists.txt  | 1 +
 userspace/libraries/LibC/errno.cpp       | 8 ++++++++
 userspace/libraries/LibC/include/errno.h | 4 ++--
 userspace/libraries/LibC/string.cpp      | 2 --
 4 files changed, 11 insertions(+), 4 deletions(-)
 create mode 100644 userspace/libraries/LibC/errno.cpp

diff --git a/userspace/libraries/LibC/CMakeLists.txt b/userspace/libraries/LibC/CMakeLists.txt
index 9cacaaf1..a6a5389e 100644
--- a/userspace/libraries/LibC/CMakeLists.txt
+++ b/userspace/libraries/LibC/CMakeLists.txt
@@ -4,6 +4,7 @@ set(LIBC_SOURCES
 	ctype.cpp
 	dirent.cpp
 	dlfcn.cpp
+	errno.cpp
 	fcntl.cpp
 	ftw.cpp
 	grp.cpp
diff --git a/userspace/libraries/LibC/errno.cpp b/userspace/libraries/LibC/errno.cpp
new file mode 100644
index 00000000..e60ef5c3
--- /dev/null
+++ b/userspace/libraries/LibC/errno.cpp
@@ -0,0 +1,8 @@
+#include <errno.h>
+
+static int s_errno = 0;
+
+int* __errno_location()
+{
+	return &s_errno;
+}
diff --git a/userspace/libraries/LibC/include/errno.h b/userspace/libraries/LibC/include/errno.h
index 2dcc3e57..d4151459 100644
--- a/userspace/libraries/LibC/include/errno.h
+++ b/userspace/libraries/LibC/include/errno.h
@@ -93,9 +93,9 @@ __BEGIN_DECLS
 
 #define EUNKNOWN		0xFF
 
-#define errno __errno
+#define errno (*__errno_location())
 
-extern int __errno;
+int* __errno_location(void);
 
 __END_DECLS
 
diff --git a/userspace/libraries/LibC/string.cpp b/userspace/libraries/LibC/string.cpp
index 853735db..fd17f356 100644
--- a/userspace/libraries/LibC/string.cpp
+++ b/userspace/libraries/LibC/string.cpp
@@ -8,8 +8,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-int errno = 0;
-
 void* memccpy(void* __restrict s1, const void* __restrict s2, int c, size_t n)
 {
 	unsigned char* dst = static_cast<unsigned char*>(s1);