diff --git a/libc/arch-x86/syscalls/prctl.S b/libc/arch-x86/syscalls/prctl.S
new file mode 100644
index 0000000..4ce5d89
--- /dev/null
+++ b/libc/arch-x86/syscalls/prctl.S
@@ -0,0 +1,35 @@
+/* autogenerated by gensyscalls.py */
+#include <sys/linux-syscalls.h>
+
+    .text
+    .type prctl, @function
+    .globl prctl
+    .align 4
+
+prctl:
+    pushl   %ebx
+    pushl   %ecx
+    pushl   %edx
+    pushl   %esi
+    pushl   %edi
+    mov     24(%esp), %ebx
+    mov     28(%esp), %ecx
+    mov     32(%esp), %edx
+    mov     36(%esp), %esi
+    mov     40(%esp), %edi
+    movl    $__NR_prctl, %eax
+    int     $0x80
+    cmpl    $-129, %eax
+    jb      1f
+    negl    %eax
+    pushl   %eax
+    call    __set_errno
+    addl    $4, %esp
+    orl     $-1, %eax
+1:
+    popl    %edi
+    popl    %esi
+    popl    %edx
+    popl    %ecx
+    popl    %ebx
+    ret