diff --git a/docs/elf-tls.md b/docs/elf-tls.md
index 4a62793..d408b3f 100644
--- a/docs/elf-tls.md
+++ b/docs/elf-tls.md
@@ -101,9 +101,9 @@
 `R_TLS_DTPOFF` is a dynamic relocation to the offset of `tls_var` within its module's `PT_TLS`
 segment.
 
-`__tls_get_addr` looks up `TlsIndex::module`'s entry in the DTV and adds `TlsIndex::offset` to the
-module's TLS block. Before it can do this, it ensures that the module's TLS block is allocated. A
-simple approach is to allocate memory lazily:
+`__tls_get_addr` looks up `TlsIndex::module_id`'s entry in the DTV and adds `TlsIndex::offset` to
+the module's TLS block. Before it can do this, it ensures that the module's TLS block is allocated.
+A simple approach is to allocate memory lazily:
 
 1. If the current thread's DTV generation count is less than the current global TLS generation, then
    `__tls_get_addr` may reallocate the DTV or free blocks for unloaded modules.
diff --git a/libc/NOTICE b/libc/NOTICE
index 9d55592..4d3a108 100644
--- a/libc/NOTICE
+++ b/libc/NOTICE
@@ -894,6 +894,34 @@
 
 -------------------------------------------------------------------
 
+Copyright (C) 2023 The Android Open Source Project
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+ * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in
+   the documentation and/or other materials provided with the
+   distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
+
+-------------------------------------------------------------------
+
 Copyright (c) 1980, 1983, 1988, 1993
    The Regents of the University of California.  All rights reserved.
 
diff --git a/libc/include/search.h b/libc/include/search.h
index 7c4989a..00deef1 100644
--- a/libc/include/search.h
+++ b/libc/include/search.h
@@ -25,9 +25,9 @@
 /** See hsearch()/hsearch_r(). */
 typedef struct entry {
   /** The string key. */
-  char* key;
+  char* _Nullable key;
   /** The associated data. */
-  void* data;
+  void* _Nullable data;
 } ENTRY;
 
 /**
@@ -57,7 +57,7 @@
 #if defined(__USE_BSD) || defined(__USE_GNU)
 /** The hash table type for hcreate_r()/hdestroy_r()/hsearch_r(). */
 struct hsearch_data {
-  struct __hsearch* __hsearch;
+  struct __hsearch* _Nullable __hsearch;
 };
 #endif
 
@@ -69,7 +69,7 @@
  *
  * Available since API level 21.
  */
-void insque(void* __element, void* __previous) __INTRODUCED_IN(21);
+void insque(void* _Nonnull __element, void* _Nullable __previous) __INTRODUCED_IN(21);
 
 /**
  * [remque(3)](http://man7.org/linux/man-pages/man3/remque.3.html) removes
@@ -77,7 +77,7 @@
  *
  * Available since API level 21.
  */
-void remque(void* __element) __INTRODUCED_IN(21);
+void remque(void* _Nonnull __element) __INTRODUCED_IN(21);
 
 /**
  * [hcreate(3)](http://man7.org/linux/man-pages/man3/hcreate.3.html)
@@ -112,7 +112,7 @@
  *
  * Available since API level 28.
  */
-ENTRY* hsearch(ENTRY __entry, ACTION __action) __INTRODUCED_IN(28);
+ENTRY* _Nullable hsearch(ENTRY __entry, ACTION __action) __INTRODUCED_IN(28);
 
 #if defined(__USE_BSD) || defined(__USE_GNU)
 
@@ -124,7 +124,7 @@
  *
  * Available since API level 28.
  */
-int hcreate_r(size_t __n, struct hsearch_data* __table) __INTRODUCED_IN(28);
+int hcreate_r(size_t __n, struct hsearch_data* _Nonnull __table) __INTRODUCED_IN(28);
 
 /**
  * [hdestroy_r(3)](http://man7.org/linux/man-pages/man3/hdestroy_r.3.html) destroys
@@ -132,7 +132,7 @@
  *
  * Available since API level 28.
  */
-void hdestroy_r(struct hsearch_data* __table) __INTRODUCED_IN(28);
+void hdestroy_r(struct hsearch_data* _Nonnull __table) __INTRODUCED_IN(28);
 
 /**
  * [hsearch_r(3)](http://man7.org/linux/man-pages/man3/hsearch_r.3.html) finds or
@@ -143,7 +143,7 @@
  *
  * Available since API level 28.
  */
-int hsearch_r(ENTRY __entry, ACTION __action, ENTRY** __result, struct hsearch_data* __table) __INTRODUCED_IN(28);
+int hsearch_r(ENTRY __entry, ACTION __action, ENTRY* _Nullable * _Nonnull __result, struct hsearch_data* _Nonnull __table) __INTRODUCED_IN(28);
 
 #endif
 
@@ -158,7 +158,7 @@
  *
  * Available since API level 21.
  */
-void* lfind(const void* __key, const void* __array, size_t* __count, size_t __size, int (*__comparator)(const void*, const void*)) __INTRODUCED_IN(21);
+void* _Nullable lfind(const void* _Nonnull __key, const void* _Nonnull __array, size_t* _Nonnull __count, size_t __size, int (* _Nonnull __comparator)(const void* _Nonnull, const void* _Nonnull)) __INTRODUCED_IN(21);
 
 /**
  * [lsearch(3)](http://man7.org/linux/man-pages/man3/lsearch.3.html) brute-force
@@ -173,7 +173,7 @@
  *
  * Available since API level 21.
  */
-void* lsearch(const void* __key, void* __array, size_t* __count, size_t __size, int (*__comparator)(const void*, const void*)) __INTRODUCED_IN(21);
+void* _Nonnull lsearch(const void* _Nonnull __key, void* _Nonnull __array, size_t* _Nonnull __count, size_t __size, int (* _Nonnull __comparator)(const void* _Nonnull, const void* _Nonnull)) __INTRODUCED_IN(21);
 
 /**
  * [tdelete(3)](http://man7.org/linux/man-pages/man3/tdelete.3.html) searches
@@ -182,13 +182,13 @@
  *
  * Returns a pointer to the parent of the deleted node, or NULL on failure.
  */
-void* tdelete(const void* __key, void** __root_ptr, int (*__comparator)(const void*, const void*));
+void* _Nullable tdelete(const void* _Nonnull __key, void* _Nullable * _Nullable __root_ptr, int (* _Nonnull __comparator)(const void* _Nonnull, const void* _Nonnull));
 
 /**
  * [tdestroy(3)](http://man7.org/linux/man-pages/man3/tdestroy.3.html) destroys
  * the hash table `__root` using `__free_fn` on each node.
  */
-void tdestroy(void* __root, void (*__free_fn)(void*));
+void tdestroy(void* _Nullable __root, void (* _Nullable __free_fn)(void* _Nullable));
 
 /**
  * [tfind(3)](http://man7.org/linux/man-pages/man3/tfind.3.html) searches
@@ -197,7 +197,7 @@
  *
  * Returns a pointer to the matching node, or NULL on failure.
  */
-void* tfind(const void* __key, void* const* __root_ptr, int (*__comparator)(const void*, const void*));
+void* _Nullable tfind(const void* _Nonnull __key, void* _Nullable const* _Nullable __root_ptr, int (* _Nonnull __comparator)(const void* _Nonnull, const void* _Nonnull));
 
 /**
  * [tsearch(3)](http://man7.org/linux/man-pages/man3/tsearch.3.html) searches
@@ -208,12 +208,12 @@
  *
  * Returns a pointer to the matching node, or to the newly-added node.
  */
-void* tsearch(const void* __key, void** __root_ptr, int (*__comparator)(const void*, const void*));
+void* _Nullable tsearch(const void* _Nonnull __key, void* _Nullable * _Nullable __root_ptr, int (* _Nonnull __comparator)(const void* _Nonnull, const void* _Nonnull));
 
 /**
  * [twalk(3)](http://man7.org/linux/man-pages/man3/twalk.3.html) calls
  * `__visitor` on every node in the tree.
  */
-void twalk(const void* __root, void (*__visitor)(const void*, VISIT, int)) __INTRODUCED_IN(21);
+void twalk(const void* _Nullable __root, void (* _Nullable __visitor)(const void* _Nullable, VISIT, int)) __INTRODUCED_IN(21);
 
 __END_DECLS
diff --git a/libc/include/utmp.h b/libc/include/utmp.h
index 7aa5718..d249f8a 100644
--- a/libc/include/utmp.h
+++ b/libc/include/utmp.h
@@ -30,7 +30,7 @@
 
 /**
  * @file utmp.h
- * @brief POSIX login records.
+ * @brief No-op implementation of non-POSIX login records. See <utmpx.h> for the POSIX equivalents.
  */
 
 #include <sys/cdefs.h>
@@ -69,12 +69,12 @@
 };
 
 struct exit_status {
-  short int e_termination;
-  short int e_exit;
+  short e_termination;
+  short e_exit;
 };
 
 struct utmp {
-  short int ut_type;
+  short ut_type;
   pid_t ut_pid;
   char ut_line[UT_LINESIZE];
   char ut_id[4];
@@ -83,7 +83,7 @@
 
   struct exit_status ut_exit;
 
-  long int ut_session;
+  long ut_session;
   struct timeval ut_tv;
 
   int32_t ut_addr_v6[4];
@@ -97,21 +97,25 @@
 __BEGIN_DECLS
 
 /**
- * Does nothing.
+ * Returns -1 and sets errno to ENOTSUP.
  */
 int utmpname(const char* _Nonnull __path);
+
 /**
  * Does nothing.
  */
 void setutent(void);
+
 /**
- * Does nothing.
+ * Does nothing and returns null.
  */
 struct utmp* _Nullable getutent(void);
+
 /**
- * Does nothing.
+ * Does nothing and returns null.
  */
 struct utmp* _Nullable pututline(const struct utmp* _Nonnull __entry);
+
 /**
  * Does nothing.
  */
diff --git a/libc/include/utmpx.h b/libc/include/utmpx.h
new file mode 100644
index 0000000..5ed8e1a
--- /dev/null
+++ b/libc/include/utmpx.h
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#pragma once
+
+/**
+ * @file utmpx.h
+ * @brief No-op implementation of POSIX login records.
+ */
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+#include <time.h>
+
+#define EMPTY         0
+#define RUN_LVL       1
+#define BOOT_TIME     2
+#define NEW_TIME      3
+#define OLD_TIME      4
+#define INIT_PROCESS  5
+#define LOGIN_PROCESS 6
+#define USER_PROCESS  7
+#define DEAD_PROCESS  8
+#define ACCOUNTING    9
+
+struct utmpx {
+  short ut_type;
+  pid_t ut_pid;
+  char ut_line[32];
+  char ut_id[4];
+  char ut_user[32];
+  char ut_host[256];
+
+  struct {
+    short e_termination;
+    short e_exit;
+  } ut_exit;
+
+  long ut_session;
+  struct timeval ut_tv;
+
+  int32_t ut_addr_v6[4];
+  char unused[20];
+};
+
+__BEGIN_DECLS
+
+/**
+ * Does nothing.
+ */
+void setutxent(void) __RENAME(setutent);
+
+/**
+ * Does nothing and returns null.
+ */
+struct utmpx* _Nullable getutxent(void) __RENAME(getutent);
+
+/**
+ * Does nothing and returns null.
+ */
+struct utmpx* _Nullable getutxid(const struct utmpx* _Nonnull __entry) __RENAME(getutent);
+
+/**
+ * Does nothing and returns null.
+ */
+struct utmpx* _Nullable getutxline(const struct utmpx* _Nonnull __entry) __RENAME(getutent);
+
+/**
+ * Does nothing and returns null.
+ */
+struct utmpx* _Nullable pututxline(const struct utmpx* _Nonnull __entry) __RENAME(pututline);
+
+/**
+ * Does nothing.
+ */
+void endutxent(void) __RENAME(endutent);
+
+__END_DECLS
diff --git a/linker/arch/arm64/tlsdesc_resolver.S b/linker/arch/arm64/tlsdesc_resolver.S
index 96eff8e..ad155e2 100644
--- a/linker/arch/arm64/tlsdesc_resolver.S
+++ b/linker/arch/arm64/tlsdesc_resolver.S
@@ -58,9 +58,9 @@
   cmp x21, x22
   b.lo .fallback
 
-  ldr x21, [x0, #8]             // TlsIndex::module
+  ldr x21, [x0, #8]             // TlsIndex::module_id
   ldr x22, [x0, #16]            // TlsIndex::offset
-  ldr x21, [x20, x21, lsl #3]   // TlsDtv::modules[module]
+  ldr x21, [x20, x21, lsl #3]   // TlsDtv::modules[module_id]
   cbz x21, .fallback
   add x0, x21, x22
   sub x0, x0, x19
diff --git a/tests/Android.bp b/tests/Android.bp
index 6d2a8d4..1949079 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -514,6 +514,7 @@
         "unistd_test.cpp",
         "utils.cpp",
         "utmp_test.cpp",
+        "utmpx_test.cpp",
         "wchar_test.cpp",
         "wctype_test.cpp",
     ],
diff --git a/tests/NOTICE b/tests/NOTICE
index 167f90b..cc99d20 100644
--- a/tests/NOTICE
+++ b/tests/NOTICE
@@ -426,3 +426,31 @@
 
 -------------------------------------------------------------------
 
+Copyright (C) 2023 The Android Open Source Project
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+ * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in
+   the documentation and/or other materials provided with the
+   distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
+
+-------------------------------------------------------------------
+
diff --git a/tests/headers/posix/utmpx_h.c b/tests/headers/posix/utmpx_h.c
new file mode 100644
index 0000000..44dfac9
--- /dev/null
+++ b/tests/headers/posix/utmpx_h.c
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <utmpx.h>
+
+#include "header_checks.h"
+
+static void utmpx_h() {
+  TYPE(struct utmpx);
+  STRUCT_MEMBER_ARRAY(struct utmpx, char/*[]*/, ut_user);
+  STRUCT_MEMBER_ARRAY(struct utmpx, char/*[]*/, ut_id);
+  STRUCT_MEMBER_ARRAY(struct utmpx, char/*[]*/, ut_line);
+  STRUCT_MEMBER(struct utmpx, pid_t, ut_pid);
+  STRUCT_MEMBER(struct utmpx, short, ut_type);
+#if !defined(__GLIBC__)
+  // POSIX says struct timeval, but glibc has an anonymous struct.
+  STRUCT_MEMBER(struct utmpx, struct timeval, ut_tv);
+#endif
+
+  TYPE(pid_t);
+  TYPE(struct timeval);
+
+  MACRO(EMPTY);
+  MACRO(BOOT_TIME);
+  MACRO(OLD_TIME);
+  MACRO(NEW_TIME);
+  MACRO(USER_PROCESS);
+  MACRO(INIT_PROCESS);
+  MACRO(LOGIN_PROCESS);
+  MACRO(DEAD_PROCESS);
+
+  FUNCTION(endutxent, void (*f)(void));
+  FUNCTION(getutxent, struct utmpx* (*f)(void));
+  FUNCTION(getutxid, struct utmpx* (*f)(const struct utmpx*));
+  FUNCTION(getutxline, struct utmpx* (*f)(const struct utmpx*));
+  FUNCTION(pututxline, struct utmpx* (*f)(const struct utmpx*));
+  FUNCTION(setutxent, void (*f)(void));
+}
diff --git a/tests/utmp_test.cpp b/tests/utmp_test.cpp
index b024818..459f9c3 100644
--- a/tests/utmp_test.cpp
+++ b/tests/utmp_test.cpp
@@ -25,6 +25,7 @@
 }
 
 TEST(utmp, smoke) {
+  // The rest of <utmp.h> is just no-op implementations, so testing is trivial.
   ASSERT_EQ(-1, utmpname("hello"));
   setutent();
   ASSERT_EQ(NULL, getutent());
diff --git a/tests/utmpx_test.cpp b/tests/utmpx_test.cpp
new file mode 100644
index 0000000..55427a6
--- /dev/null
+++ b/tests/utmpx_test.cpp
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <gtest/gtest.h>
+
+#include <utmpx.h>
+
+TEST(utmpx, smoke) {
+  // Our utmpx "implementation" just calls the utmp no-op functions.
+  setutxent();
+  utmpx empty = {.ut_type = EMPTY};
+  ASSERT_EQ(NULL, getutxent());
+  ASSERT_EQ(NULL, getutxid(&empty));
+  ASSERT_EQ(NULL, getutxline(&empty));
+  endutxent();
+  ASSERT_EQ(NULL, pututxline(&empty));
+}