diff --git a/libc/Android.bp b/libc/Android.bp
index 5ae8c4f..e0d8994 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -941,6 +941,7 @@
         "bionic/pthread_detach.cpp",
         "bionic/pthread_equal.cpp",
         "bionic/pthread_exit.cpp",
+        "bionic/pthread_getaffinity.cpp",
         "bionic/pthread_getcpuclockid.cpp",
         "bionic/pthread_getschedparam.cpp",
         "bionic/pthread_gettid_np.cpp",
@@ -954,6 +955,7 @@
         "bionic/pthread_sigqueue.cpp",
         "bionic/pthread_self.cpp",
         "bionic/pthread_setname_np.cpp",
+        "bionic/pthread_setaffinity.cpp",
         "bionic/pthread_setschedparam.cpp",
         "bionic/pthread_spinlock.cpp",
         "bionic/ptrace.cpp",
diff --git a/libc/bionic/pthread_getaffinity.cpp b/libc/bionic/pthread_getaffinity.cpp
new file mode 100644
index 0000000..9ce436c
--- /dev/null
+++ b/libc/bionic/pthread_getaffinity.cpp
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2024 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 <errno.h>
+
+#include "private/ErrnoRestorer.h"
+#include "pthread_internal.h"
+
+int pthread_getaffinity_np(pthread_t t, size_t cpu_set_size, cpu_set_t* cpu_set) {
+  ErrnoRestorer errno_restorer;
+
+  pid_t tid = __pthread_internal_gettid(t, "pthread_getaffinity_np");
+  if (tid == -1) return ESRCH;
+
+  if (sched_getaffinity(tid, cpu_set_size, cpu_set) == -1) return errno;
+  return 0;
+}
diff --git a/libc/bionic/pthread_setaffinity.cpp b/libc/bionic/pthread_setaffinity.cpp
new file mode 100644
index 0000000..6db418e
--- /dev/null
+++ b/libc/bionic/pthread_setaffinity.cpp
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2024 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 <errno.h>
+
+#include "private/ErrnoRestorer.h"
+#include "pthread_internal.h"
+
+int pthread_setaffinity_np(pthread_t t, size_t cpu_set_size, const cpu_set_t* cpu_set) {
+  ErrnoRestorer errno_restorer;
+
+  pid_t tid = __pthread_internal_gettid(t, "pthread_setaffinity_np");
+  if (tid == -1) return ESRCH;
+
+  if (sched_setaffinity(tid, cpu_set_size, cpu_set) == -1) return errno;
+  return 0;
+}
diff --git a/libc/include/pthread.h b/libc/include/pthread.h
index 8b78a74..71ea8f9 100644
--- a/libc/include/pthread.h
+++ b/libc/include/pthread.h
@@ -314,17 +314,60 @@
 
 pthread_t pthread_self(void) __attribute_const__;
 
-#if defined(__USE_GNU)
-
-#if __BIONIC_AVAILABILITY_GUARD(26)
+#if __USE_GNU  && __BIONIC_AVAILABILITY_GUARD(26)
+/**
+ * [pthread_getname_np(3)](https://man7.org/linux/man-pages/man3/pthread_getname_np.3.html)
+ * gets the name of the given thread.
+ * Names are at most 16 bytes (including '\0').
+ *
+ * Returns 0 on success and returns an error number on failure.
+ *
+ * Available since API level 26.
+ */
 int pthread_getname_np(pthread_t __pthread, char* _Nonnull __buf, size_t __n) __INTRODUCED_IN(26);
-#endif /* __BIONIC_AVAILABILITY_GUARD(26) */
-
 #endif
-/* TODO: this should be __USE_GNU too. */
+
+/**
+ * [pthread_setname_np(3)](https://man7.org/linux/man-pages/man3/pthread_setname_np.3.html)
+ * sets the name of the given thread.
+ * Names are at most 16 bytes (including '\0').
+ * Truncation must be done by the caller;
+ * calls with longer names will fail with ERANGE.
+ *
+ * Returns 0 on success and returns an error number on failure.
+ *
+ * This should only have been available under _GNU_SOURCE,
+ * but is always available on Android by historical accident.
+ */
 int pthread_setname_np(pthread_t __pthread, const char* _Nonnull __name);
 
 /**
+ * [pthread_getaffinity_np(3)](https://man7.org/linux/man-pages/man3/pthread_getaffinity_np.3.html)
+ * gets the CPU affinity mask for the given thread.
+ *
+ * Returns 0 on success and returns an error number on failure.
+ *
+ * Available since API level 36.
+ * See sched_getaffinity() and pthread_gettid_np() for greater portability.
+ */
+#if __USE_GNU && __BIONIC_AVAILABILITY_GUARD(36)
+int pthread_getaffinity_np(pthread_t __pthread, size_t __cpu_set_size, cpu_set_t* __cpu_set) __INTRODUCED_IN(36);
+#endif
+
+/**
+ * [pthread_setaffinity_np(3)](https://man7.org/linux/man-pages/man3/pthread_setaffinity_np.3.html)
+ * sets the CPU affinity mask for the given thread.
+ *
+ * Returns 0 on success and returns an error number on failure.
+ *
+ * Available since API level 36.
+ * See sched_getaffinity() and pthread_gettid_np() for greater portability.
+ */
+#if __USE_GNU && __BIONIC_AVAILABILITY_GUARD(36)
+int pthread_setaffinity_np(pthread_t __pthread, size_t __cpu_set_size, const cpu_set_t* __cpu_set) __INTRODUCED_IN(36);
+#endif
+
+/**
  * [pthread_setschedparam(3)](https://man7.org/linux/man-pages/man3/pthread_setschedparam.3.html)
  * sets the scheduler policy and parameters of the given thread.
  *
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index d8636a2..86dcc39 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1612,6 +1612,8 @@
   global:
     lchmod;
     mseal;
+    pthread_getaffinity_np;
+    pthread_setaffinity_np;
     qsort_r;
     sig2str;
     str2sig;