+ if (libc.tls_size > sizeof builtin_tls) {
+#ifndef SYS_mmap2
+#define SYS_mmap2 SYS_mmap
+#endif
+ mem = (void *)__syscall(
+ SYS_mmap2,
+ 0, libc.tls_size, PROT_READ|PROT_WRITE,
+ MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+ /* -4095...-1 cast to void * will crash on dereference anyway,
+ * so don't bloat the init code checking for error codes and
+ * explicitly calling a_crash(). */
+ } else {
+ mem = builtin_tls;
+ }