[fusl] Update fusl

fusl/src/ldso/dlerror.c

+#include <dlfcn.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include "pthread_impl.h"
+#include "libc.h"
+
+char *dlerror()
+{
+        pthread_t self = __pthread_self();
+        if (!self->dlerror_flag) return 0;
+        self->dlerror_flag = 0;
+        char *s = self->dlerror_buf;
+        if (s == (void *)-1)
+                return "Dynamic linker failed to allocate memory for error message";
+        else
+                return s;
+}
+
+void __dl_thread_cleanup(void)
+{
+        pthread_t self = __pthread_self();
+        if (self->dlerror_buf != (void *)-1)
+                free(self->dlerror_buf);
+}
+
+__attribute__((__visibility__("hidden")))
+void __dl_vseterr(const char *fmt, va_list ap)
+{
+        va_list ap2;
+        va_copy(ap2, ap);
+        pthread_t self = __pthread_self();
+        if (self->dlerror_buf != (void *)-1)
+                free(self->dlerror_buf);
+        size_t len = vsnprintf(0, 0, fmt, ap2);
+        va_end(ap2);
+        char *buf = malloc(len+1);
+        if (buf) {
+                vsnprintf(buf, len+1, fmt, ap);
+        } else {
+                buf = (void *)-1;       
+        }
+        self->dlerror_buf = buf;
+        self->dlerror_flag = 1;
+}
+
+__attribute__((__visibility__("hidden")))
+void __dl_seterr(const char *fmt, ...)
+{
+        va_list ap;
+        va_start(ap, fmt);
+        __dl_vseterr(fmt, ap);
+        va_end(ap);
+}
+
+__attribute__((__visibility__("hidden")))
+int __dl_invalid_handle(void *);
+
+static int stub_invalid_handle(void *h)
+{
+        __dl_seterr("Invalid library handle %p", (void *)h);
+        return 1;
+}
+
+weak_alias(stub_invalid_handle, __dl_invalid_handle);