Fix compilation with musl.

Bug: https://github.com/ROCm/ROCR-Runtime/issues/181
--- a/core/inc/checked.h
+++ b/core/inc/checked.h
@@ -58,7 +58,7 @@ template <uint64_t code, bool multiProcess = false> class Check final {
   Check(const Check&) { object_ = uintptr_t(this) ^ uintptr_t(code); }
   Check(Check&&) { object_ = uintptr_t(this) ^ uintptr_t(code); }
 
-  ~Check() { object_ = NULL; }
+  ~Check() { object_ = uintptr_t(NULL); }
 
   const Check& operator=(Check&& rhs) { return *this; }
   const Check& operator=(const Check& rhs) { return *this; }
--- a/core/runtime/default_signal.cpp
+++ b/core/runtime/default_signal.cpp
@@ -57,7 +57,7 @@ int BusyWaitSignal::rtti_id_ = 0;
 BusyWaitSignal::BusyWaitSignal(SharedSignal* abi_block, bool enableIPC)
     : Signal(abi_block, enableIPC) {
   signal_.kind = AMD_SIGNAL_KIND_USER;
-  signal_.event_mailbox_ptr = NULL;
+  signal_.event_mailbox_ptr = uint64_t(NULL);
 }
 
 hsa_signal_value_t BusyWaitSignal::LoadRelaxed() {
--- a/core/runtime/hsa.cpp
+++ b/core/runtime/hsa.cpp
@@ -155,7 +155,7 @@ template <class T> struct ValidityError<const T*> {
 
 template <class T>
 static __forceinline bool IsValid(T* ptr) {
-  return (ptr == NULL) ? NULL : ptr->IsValid();
+  return (ptr == NULL) ? false : ptr->IsValid();
 }
 
 namespace AMD {
--- a/core/util/lnx/os_linux.cpp
+++ b/core/util/lnx/os_linux.cpp
@@ -111,9 +111,12 @@ class os_thread {
       }
     }
 
+    int cores = 0;
+    cpu_set_t* cpuset = nullptr;
+
     if (core::Runtime::runtime_singleton_->flag().override_cpu_affinity()) {
-      int cores = get_nprocs_conf();
-      cpu_set_t* cpuset = CPU_ALLOC(cores);
+      cores = get_nprocs_conf();
+      cpuset = CPU_ALLOC(cores);
       if (cpuset == nullptr) {
         fprintf(stderr, "CPU_ALLOC failed: %s\n", strerror(errno));
         return;
@@ -122,12 +125,6 @@ class os_thread {
       for (int i = 0; i < cores; i++) {
         CPU_SET(i, cpuset);
       }
-      err = pthread_attr_setaffinity_np(&attrib, CPU_ALLOC_SIZE(cores), cpuset);
-      CPU_FREE(cpuset);
-      if (err != 0) {
-        fprintf(stderr, "pthread_attr_setaffinity_np failed: %s\n", strerror(err));
-        return;
-      }
     }
 
     err = pthread_create(&thread, &attrib, ThreadTrampoline, args.get());
@@ -157,6 +154,14 @@ class os_thread {
     if (err != 0) {
       fprintf(stderr, "pthread_attr_destroy failed: %s\n", strerror(err));
     }
+
+    if (thread && cores && cpuset) {
+      err = pthread_setaffinity_np(thread, CPU_ALLOC_SIZE(cores), cpuset);
+      CPU_FREE(cpuset);
+      if (err != 0) {
+        fprintf(stderr, "pthread_setaffinity_np failed: %s\n", strerror(err));
+      }
+    }
   }
 
   os_thread(os_thread&& rhs) {
@@ -617,11 +622,13 @@ SharedMutex CreateSharedMutex() {
     fprintf(stderr, "rw lock attribute init failed: %s\n", strerror(err));
     return nullptr;
   }
+#if defined(__GLIBC__)
   err = pthread_rwlockattr_setkind_np(&attrib, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP);
   if (err != 0) {
     fprintf(stderr, "Set rw lock attribute failure: %s\n", strerror(err));
     return nullptr;
   }
+#endif
 
   pthread_rwlock_t* lock = new pthread_rwlock_t;
   err = pthread_rwlock_init(lock, &attrib);
--- a/core/util/utils.h
+++ b/core/util/utils.h
@@ -74,7 +74,7 @@ static __forceinline void* _aligned_malloc(size_t size, size_t alignment) {
   return aligned_alloc(alignment, size);
 #else
   void *mem = NULL;
-  if (NULL != posix_memalign(&mem, alignment, size))
+  if (0 != posix_memalign(&mem, alignment, size))
     return NULL;
   return mem;
 #endif
--- a/image/util.h
+++ b/image/util.h
@@ -95,7 +95,7 @@ static __forceinline void* _aligned_malloc(size_t size, size_t alignment) {
   return aligned_alloc(alignment, size);
 #else
   void* mem = NULL;
-  if (NULL != posix_memalign(&mem, alignment, size)) return NULL;
+  if (0 != posix_memalign(&mem, alignment, size)) return NULL;
   return mem;
 #endif
 }