diff --git a/libc/SECCOMP_ALLOWLIST_COMMON.TXT b/libc/SECCOMP_ALLOWLIST_COMMON.TXT
index 4a8d501..67b662e 100644
--- a/libc/SECCOMP_ALLOWLIST_COMMON.TXT
+++ b/libc/SECCOMP_ALLOWLIST_COMMON.TXT
@@ -74,5 +74,3 @@
 int rt_sigtimedwait_time64(const sigset64_t*, siginfo_t*, const timespec64*, size_t) lp32
 int futex_time64(int*, int, int, const timespec64*, int*, int) lp32
 int sched_rr_get_interval_time64(pid_t, timespec64*) lp32
-# Since Linux 6.4, not in glibc (https://www.openwall.com/lists/libc-coord/2023/07/13/1).
-int riscv_hwprobe(riscv_hwprobe*, size_t, size_t, unsigned long*, unsigned) riscv64
diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index e8dde7c..079acf9 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -357,6 +357,7 @@
 
 # riscv64-specific
 int __riscv_flush_icache:riscv_flush_icache(void*, void*, unsigned long) riscv64
+int __riscv_hwprobe:riscv_hwprobe(riscv_hwprobe*, size_t, size_t, unsigned long*, unsigned) riscv64
 
 # x86-specific
 int     __set_thread_area:set_thread_area(void*) x86
diff --git a/libc/include/sys/hwprobe.h b/libc/include/sys/hwprobe.h
new file mode 100644
index 0000000..f2fd98d
--- /dev/null
+++ b/libc/include/sys/hwprobe.h
@@ -0,0 +1,58 @@
+/*
+ * 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
+
+#if __riscv
+
+/**
+ * @file sys/hwprobe.h
+ * @brief RISC-V hardware probing.
+ */
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+/* Pull in struct riscv_hwprobe and corresponding constants. */
+#include <asm/hwprobe.h>
+
+__BEGIN_DECLS
+
+/**
+ * [__riscv_hwprobe(2)](https://docs.kernel.org/riscv/hwprobe.html)
+ * queries hardware characteristics.
+ *
+ * A `__cpu_count` of 0 and null `__cpus` means "all online cpus".
+ *
+ * Returns 0 on success and returns -1 and sets `errno` on failure.
+ */
+int __riscv_hwprobe(struct riscv_hwprobe* _Nonnull __pairs, size_t __pair_count, size_t __cpu_count, unsigned long* _Nullable __cpus, unsigned __flags);
+
+__END_DECLS
+
+#endif
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index 86c8288..e90618d 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1590,6 +1590,7 @@
     mbsrtowcs_l;
     mktime_z;
     __riscv_flush_icache; # riscv64
+    __riscv_hwprobe; # riscv64
     timespec_getres;
     tzalloc;
     tzfree;