diff --git a/libc/include/bits/glibc-syscalls.h b/libc/include/bits/glibc-syscalls.h
index 52eff56..e831bdc 100644
--- a/libc/include/bits/glibc-syscalls.h
+++ b/libc/include/bits/glibc-syscalls.h
@@ -1,6 +1,5 @@
-/* Generated by gensyscalls.py. Do not edit. */
-#ifndef _BIONIC_BITS_GLIBC_SYSCALLS_H_
-#define _BIONIC_BITS_GLIBC_SYSCALLS_H_
+/* Generated file. Do not edit. */
+#pragma once
 #if defined(__NR__llseek)
   #define SYS__llseek __NR__llseek
 #endif
@@ -61,12 +60,6 @@
 #if defined(__NR_brk)
   #define SYS_brk __NR_brk
 #endif
-#if defined(__NR_cachectl)
-  #define SYS_cachectl __NR_cachectl
-#endif
-#if defined(__NR_cacheflush)
-  #define SYS_cacheflush __NR_cacheflush
-#endif
 #if defined(__NR_capget)
   #define SYS_capget __NR_capget
 #endif
@@ -1123,9 +1116,6 @@
 #if defined(__NR_syslog)
   #define SYS_syslog __NR_syslog
 #endif
-#if defined(__NR_sysmips)
-  #define SYS_sysmips __NR_sysmips
-#endif
 #if defined(__NR_tee)
   #define SYS_tee __NR_tee
 #endif
@@ -1150,9 +1140,6 @@
 #if defined(__NR_timer_settime)
   #define SYS_timer_settime __NR_timer_settime
 #endif
-#if defined(__NR_timerfd)
-  #define SYS_timerfd __NR_timerfd
-#endif
 #if defined(__NR_timerfd_create)
   #define SYS_timerfd_create __NR_timerfd_create
 #endif
@@ -1255,4 +1242,3 @@
 #if defined(__NR_writev)
   #define SYS_writev __NR_writev
 #endif
-#endif /* _BIONIC_BITS_GLIBC_SYSCALLS_H_ */
diff --git a/libc/kernel/tools/update_all.py b/libc/kernel/tools/update_all.py
index 0f30ecd..9d5b02d 100755
--- a/libc/kernel/tools/update_all.py
+++ b/libc/kernel/tools/update_all.py
@@ -4,7 +4,7 @@
 from defaults import *
 from utils import *
 
-def usage():
+def Usage():
     print """\
   usage: %(progname)s [kernel-original-path] [kernel-modified-path]
 
@@ -24,7 +24,7 @@
 """ % { "progname" : os.path.basename(sys.argv[0]) }
     sys.exit(0)
 
-def processFiles(updater, original_dir, modified_dir, src_rel_dir, update_rel_dir):
+def ProcessFiles(updater, original_dir, modified_dir, src_rel_dir, update_rel_dir):
     # Delete the old headers before updating to the new headers.
     update_dir = os.path.join(get_kernel_dir(), update_rel_dir)
     shutil.rmtree(update_dir)
@@ -64,15 +64,64 @@
             update_path = os.path.join(update_rel_dir, rel_path)
             print "cleaning %s -> %s (%s)" % (src_str, update_path, state)
 
+
+# This lets us support regular system calls like __NR_write and also weird
+# ones like __ARM_NR_cacheflush, where the NR doesn't come at the start.
+def make__NR_name(name):
+    if name.startswith('__ARM_NR_'):
+        return name
+    else:
+        return '__NR_%s' % (name)
+
+
+# Scan Linux kernel asm/unistd.h files containing __NR_* constants
+# and write out equivalent SYS_* constants for glibc source compatibility.
+def GenerateGlibcSyscallsHeader(updater):
+    libc_root = '%s/bionic/libc/' % os.environ['ANDROID_BUILD_TOP']
+
+    # Collect the set of all syscalls for all architectures.
+    syscalls = set()
+    pattern = re.compile(r'^\s*#\s*define\s*__NR_([a-z_]\S+)')
+    for unistd_h in ['kernel/uapi/asm-generic/unistd.h',
+                     'kernel/uapi/asm-arm/asm/unistd.h',
+                     'kernel/uapi/asm-arm/asm/unistd-common.h',
+                     'kernel/uapi/asm-arm/asm/unistd-eabi.h',
+                     'kernel/uapi/asm-arm/asm/unistd-oabi.h',
+                     'kernel/uapi/asm-x86/asm/unistd_32.h',
+                     'kernel/uapi/asm-x86/asm/unistd_64.h',
+                     'kernel/uapi/asm-x86/asm/unistd_x32.h']:
+        for line in open(os.path.join(libc_root, unistd_h)):
+            m = re.search(pattern, line)
+            if m:
+                nr_name = m.group(1)
+                if 'reserved' not in nr_name and 'unused' not in nr_name:
+                    syscalls.add(nr_name)
+
+    # Create a single file listing them all.
+    # Note that the input files include #if trickery, so even for a single
+    # architecture we don't know exactly which ones are available.
+    # https://b.corp.google.com/issues/37110151
+    content = '/* Generated file. Do not edit. */\n'
+    content += '#pragma once\n'
+
+    for syscall in sorted(syscalls):
+        nr_name = make__NR_name(syscall)
+        content += '#if defined(%s)\n' % nr_name
+        content += '  #define SYS_%s %s\n' % (syscall, nr_name)
+        content += '#endif\n'
+
+    updater.editFile('%s/include/bits/glibc-syscalls.h' % libc_root, content)
+
+
 try:
     optlist, args = getopt.getopt(sys.argv[1:], '')
 except:
     # Unrecognized option
     sys.stderr.write("error: unrecognized option\n")
-    usage()
+    Usage()
 
 if len(optlist) > 0 or len(args) > 2:
-    usage()
+    Usage()
 
 if len(args) > 0:
     original_dir = args[0]
@@ -91,10 +140,16 @@
     panic("The kernel modified directory %s is not a directory\n" % modified_dir)
 
 updater = BatchFileUpdater()
+
 # Process the original uapi headers first.
-processFiles(updater, original_dir, modified_dir, "uapi", "uapi"),
+ProcessFiles(updater, original_dir, modified_dir, "uapi", "uapi"),
 
 # Now process the special files.
-processFiles(updater, original_dir, modified_dir, "scsi", os.path.join("android", "scsi", "scsi"))
+ProcessFiles(updater, original_dir, modified_dir, "scsi", os.path.join("android", "scsi", "scsi"))
 
 updater.updateGitFiles()
+
+# Now re-generate the <bits/glibc-syscalls.h> from the new uapi headers.
+updater = BatchFileUpdater()
+GenerateGlibcSyscallsHeader(updater)
+updater.updateGitFiles()
diff --git a/libc/tools/gensyscalls.py b/libc/tools/gensyscalls.py
index 9a3b95e..31a8bd0 100755
--- a/libc/tools/gensyscalls.py
+++ b/libc/tools/gensyscalls.py
@@ -527,7 +527,6 @@
     def __init__(self):
         self.old_stubs = []
         self.new_stubs = []
-        self.other_files = []
         self.syscalls = []
 
 
@@ -565,56 +564,6 @@
                 syscall["asm-x86_64"] = add_footer(64, x86_64_genstub(syscall), syscall)
 
 
-    # Scan Linux kernel asm/unistd.h files containing __NR_* constants
-    # and write out equivalent SYS_* constants for glibc source compatibility.
-    def gen_glibc_syscalls_h(self):
-        glibc_syscalls_h_path = "include/bits/glibc-syscalls.h"
-        logging.info("generating " + glibc_syscalls_h_path)
-        glibc_fp = create_file(glibc_syscalls_h_path)
-        glibc_fp.write("/* %s */\n" % warning)
-        glibc_fp.write("#ifndef _BIONIC_BITS_GLIBC_SYSCALLS_H_\n")
-        glibc_fp.write("#define _BIONIC_BITS_GLIBC_SYSCALLS_H_\n")
-
-        # Collect the set of all syscalls for all architectures.
-        syscalls = set()
-        pattern = re.compile(r'^\s*#\s*define\s*__NR_([a-z_]\S+)')
-        for unistd_h in ["kernel/uapi/asm-generic/unistd.h",
-                         "kernel/uapi/asm-arm/asm/unistd.h",
-                         "kernel/uapi/asm-arm/asm/unistd-common.h",
-                         "kernel/uapi/asm-arm/asm/unistd-eabi.h",
-                         "kernel/uapi/asm-arm/asm/unistd-oabi.h",
-                         "kernel/uapi/asm-mips/asm/unistd.h",
-                         "kernel/uapi/asm-mips/asm/unistd_n32.h",
-                         "kernel/uapi/asm-mips/asm/unistd_n64.h",
-                         "kernel/uapi/asm-mips/asm/unistd_nr_n32.h",
-                         "kernel/uapi/asm-mips/asm/unistd_nr_n64.h",
-                         "kernel/uapi/asm-mips/asm/unistd_nr_o32.h",
-                         "kernel/uapi/asm-mips/asm/unistd_o32.h",
-                         "kernel/uapi/asm-x86/asm/unistd_32.h",
-                         "kernel/uapi/asm-x86/asm/unistd_64.h",
-                         "kernel/uapi/asm-x86/asm/unistd_x32.h"]:
-          for line in open(os.path.join(bionic_libc_root, unistd_h)):
-            m = re.search(pattern, line)
-            if m:
-              nr_name = m.group(1)
-              if 'reserved' not in nr_name and 'unused' not in nr_name:
-                syscalls.add(nr_name)
-
-        # Write out a single file listing them all. Note that the input
-        # files include #if trickery, so even for a single architecture
-        # we don't know exactly which ones are available.
-        # https://code.google.com/p/android/issues/detail?id=215853
-        for syscall in sorted(syscalls):
-          nr_name = make__NR_name(syscall)
-          glibc_fp.write("#if defined(%s)\n" % nr_name)
-          glibc_fp.write("  #define SYS_%s %s\n" % (syscall, nr_name))
-          glibc_fp.write("#endif\n")
-
-        glibc_fp.write("#endif /* _BIONIC_BITS_GLIBC_SYSCALLS_H_ */\n")
-        glibc_fp.close()
-        self.other_files.append(glibc_syscalls_h_path)
-
-
     # Write each syscall stub.
     def gen_syscall_stubs(self):
         for syscall in self.syscalls:
@@ -645,16 +594,15 @@
             logging.info("creating %s..." % bionic_temp)
             make_dir(bionic_temp)
 
-        logging.info("re-generating stubs and support files...")
+        logging.info("re-generating stubs...")
 
-        self.gen_glibc_syscalls_h()
         self.gen_syscall_stubs()
 
         logging.info("comparing files...")
         adds    = []
         edits   = []
 
-        for stub in self.new_stubs + self.other_files:
+        for stub in self.new_stubs:
             tmp_file = os.path.join(bionic_temp, stub)
             libc_file = os.path.join(bionic_libc_root, stub)
             if not os.path.exists(libc_file):