Integrate newlib locks with libnx (R)Mutex (untested, incomplete)

nx/include/switch/kernel/mutex.h

@@ -1,13 +1,9 @@
 // Copyright 2017 plutoo
-typedef struct {
-    u32 Tag;
-} Mutex;
+#pragma once
+#include <sys/lock.h>
 
-typedef struct {
-    u32    Owner;
-    Mutex  Lock;
-    size_t Count;
-} RMutex;
+typedef _LOCK_T Mutex;
+typedef _LOCK_RECURSIVE_T RMutex;
 
 void mutexLock(Mutex* m);
 void mutexUnlock(Mutex* m);

nx/source/kernel/mutex.c

@@ -11,7 +11,7 @@ static u32 _GetTag() {
 
 void mutexLock(Mutex* m) {
     u32 self = _GetTag();
-    u32 cur = __sync_val_compare_and_swap(&m->Tag, 0, self);
+    u32 cur = __sync_val_compare_and_swap(m, 0, self);
 
     while (1) {
         if (cur == 0) {
@@ -26,44 +26,44 @@ void mutexLock(Mutex* m) {
 
         if (cur & HAS_LISTENERS) {
             // The flag is already set, we can use the syscall.
-            svcArbitrateLock(cur &~ HAS_LISTENERS, &m->Tag, self);
+            svcArbitrateLock(cur &~ HAS_LISTENERS, (u32*)m, self);
         }
         else {
             // The flag is not set, we need to set it.
-            u32 old = __sync_val_compare_and_swap(&m->Tag, cur, cur | HAS_LISTENERS);
+            u32 old = __sync_val_compare_and_swap(m, cur, cur | HAS_LISTENERS);
 
             if (old == cur) {
                 // Flag was set successfully.
-                svcArbitrateLock(cur &~ HAS_LISTENERS, &m->Tag, self);
+                svcArbitrateLock(cur &~ HAS_LISTENERS, (u32*)m, self);
             }
         }
 
-        cur = __sync_val_compare_and_swap(&m->Tag, 0, self);
+        cur = __sync_val_compare_and_swap(m, 0, self);
     }
 }
 
 void mutexUnlock(Mutex* m) {
     u32 self = _GetTag();
-    u32 old = __sync_val_compare_and_swap(&m->Tag, self, 0);
+    u32 old = __sync_val_compare_and_swap(m, self, 0);
 
     if (old & HAS_LISTENERS) {
-        svcArbitrateUnlock(&m->Tag);
+        svcArbitrateUnlock((u32*)m);
     }
 }
 
 void rmutexLock(RMutex* m) {
-    if (m->Owner == _GetTag()) {
-        m->Count++;
+    if (m->thread_tag == _GetTag()) {
+        m->counter++;
     }
     else {
-        mutexLock(&m->Lock);
-        m->Owner = _GetTag();
+        mutexLock(&m->lock);
+        m->thread_tag = _GetTag();
     }
 }
 
 void rmutexUnlock(RMutex* m) {
-    if (--m->Count == 0) {
-        m->Owner = 0;
-        mutexUnlock(&m->Lock);
+    if (--m->counter == 0) {
+        m->thread_tag = 0;
+        mutexUnlock(&m->lock);
     }
 }

nx/source/system/init.c

@@ -63,7 +63,7 @@ void __attribute__((weak)) __libnx_init(void)
     __libc_init_array();
 }
 
-void __attribute__((weak)) NORETURN __libnx_exit(void)
+void __attribute__((weak)) NORETURN __libnx_exit(int rc)
 {
     // Call destructors.
     void __libc_fini_array(void);

nx/source/system/newlib.c

@@ -4,15 +4,15 @@
 #include <sys/lock.h>
 #include <sys/reent.h>
 
-void __attribute__((weak)) NORETURN __libnx_exit(void);
-
-
-static void NORETURN _ExitImpl(int rc) {
-    __libnx_exit();
-}
+void __attribute__((weak)) NORETURN __libnx_exit(int rc);
 
 void newlibSetup() {
-    void exitImpl(int rc);
-    __syscalls.exit = _ExitImpl;
+    // Register newlib syscalls
+    __syscalls.exit = __libnx_exit;
 
+    // Register locking syscalls
+    __syscalls.lock_acquire           = mutexLock;
+    __syscalls.lock_release           = mutexUnlock;
+    __syscalls.lock_acquire_recursive = rmutexLock;
+    __syscalls.lock_release_recursive = rmutexUnlock;
 }