diff --git a/libc/bionic/grp_pwd.cpp b/libc/bionic/grp_pwd.cpp
index 078a0b3..2823662 100644
--- a/libc/bionic/grp_pwd.cpp
+++ b/libc/bionic/grp_pwd.cpp
@@ -467,7 +467,16 @@
 
 char* getlogin() { // NOLINT: implementing bad function.
   passwd *pw = getpwuid(getuid()); // NOLINT: implementing bad function in terms of bad function.
-  return (pw != NULL) ? pw->pw_name : NULL;
+  return pw ? pw->pw_name : nullptr;
+}
+
+int getlogin_r(char* buf, size_t size) {
+  char* login = getlogin();
+  if (login == nullptr) return errno;
+  size_t login_length = strlen(login) + 1;
+  if (login_length > size) return ERANGE;
+  memcpy(buf, login, login_length);
+  return 0;
 }
 
 void setpwent() {
diff --git a/libc/bionic/sysconf.cpp b/libc/bionic/sysconf.cpp
index 4a23fec..7325dbd 100644
--- a/libc/bionic/sysconf.cpp
+++ b/libc/bionic/sysconf.cpp
@@ -135,12 +135,12 @@
     case _SC_TIMERS:            return _POSIX_TIMERS;
     case _SC_GETGR_R_SIZE_MAX:  return 1024;
     case _SC_GETPW_R_SIZE_MAX:  return 1024;
-    case _SC_LOGIN_NAME_MAX:    return 256;   // Seems default on linux.
+    case _SC_LOGIN_NAME_MAX:    return LOGIN_NAME_MAX;
     case _SC_THREAD_DESTRUCTOR_ITERATIONS: return PTHREAD_DESTRUCTOR_ITERATIONS;
     case _SC_THREAD_KEYS_MAX:   return PTHREAD_KEYS_MAX;
     case _SC_THREAD_STACK_MIN:    return PTHREAD_STACK_MIN;
     case _SC_THREAD_THREADS_MAX:  return -1; // No specific limit.
-    case _SC_TTY_NAME_MAX:        return 32; // Seems default on linux.
+    case _SC_TTY_NAME_MAX:        return TTY_NAME_MAX;
     case _SC_THREADS:             return _POSIX_THREADS;
     case _SC_THREAD_ATTR_STACKADDR:   return _POSIX_THREAD_ATTR_STACKADDR;
     case _SC_THREAD_ATTR_STACKSIZE:   return _POSIX_THREAD_ATTR_STACKSIZE;