diff --git a/build/config.mk b/build/config.mk
index 753ebb0ae..e7e2b08ab 100644
--- a/build/config.mk
+++ b/build/config.mk
@@ -152,6 +152,10 @@ CONFIG_CCFLAGS +=			\
 	-fomit-frame-pointer		\
 	-momit-leaf-frame-pointer	\
 	-foptimize-sibling-calls
+CONFIG_OFLAGS +=			\
+	-g0
+CONFIG_LDFLAGS +=			\
+	-S
 TARGET_ARCH ?=				\
 	-msse3
 PYFLAGS +=				\
@@ -180,6 +184,10 @@ CONFIG_CPPFLAGS +=			\
 	-DSUPPORT_VECTOR=1
 DEFAULT_COPTS +=			\
 	-mred-zone
+CONFIG_OFLAGS +=			\
+	-g0
+CONFIG_LDFLAGS +=			\
+	-S
 CONFIG_CCFLAGS +=			\
 	-Os				\
 	-fno-align-functions		\
@@ -212,6 +220,10 @@ CONFIG_CPPFLAGS +=		\
 	-DSUPPORT_VECTOR=113
 DEFAULT_COPTS +=		\
 	-mred-zone
+CONFIG_OFLAGS +=		\
+	-g0
+CONFIG_LDFLAGS +=		\
+	-S
 CONFIG_CCFLAGS +=		\
 	-Os			\
 	-fno-align-functions	\
@@ -249,6 +261,10 @@ CONFIG_CCFLAGS +=		\
 	-fno-align-jumps	\
 	-fno-align-labels	\
 	-fno-align-loops
+CONFIG_OFLAGS +=		\
+	-g0
+CONFIG_LDFLAGS +=		\
+	-S
 TARGET_ARCH ?=			\
 	-msse3
 endif
@@ -278,6 +294,10 @@ CONFIG_CCFLAGS +=		\
 	-fno-align-jumps	\
 	-fno-align-labels	\
 	-fno-align-loops
+CONFIG_OFLAGS +=		\
+	-g0
+CONFIG_LDFLAGS +=		\
+	-S
 TARGET_ARCH ?=			\
 	-msse3
 endif
diff --git a/examples/clock_getres.c b/examples/clock_getres.c
new file mode 100644
index 000000000..e40a47d54
--- /dev/null
+++ b/examples/clock_getres.c
@@ -0,0 +1,56 @@
+#if 0
+/*─────────────────────────────────────────────────────────────────╗
+│ To the extent possible under law, Justine Tunney has waived      │
+│ all copyright and related or neighboring rights to this file,    │
+│ as it is written in the following disclaimers:                   │
+│   • http://unlicense.org/                                        │
+│   • http://creativecommons.org/publicdomain/zero/1.0/            │
+╚─────────────────────────────────────────────────────────────────*/
+#endif
+#include "libc/calls/struct/timespec.h"
+#include "libc/errno.h"
+#include "libc/intrin/describeflags.internal.h"
+#include "libc/intrin/kprintf.h"
+#include "libc/str/str.h"
+#include "libc/sysv/consts/clock.h"
+
+int n;
+int shown[64];
+
+void show(int clock) {
+  int i;
+  struct timespec ts;
+  if (clock == 127) return;
+  for (i = 0; i < n; ++i) {
+    if (shown[i] == clock) {
+      return;
+    }
+  }
+  shown[n++] = clock;
+  if (clock_getres(clock, &ts) != -1) {
+    kprintf("%s %'ld ns\n", DescribeClockName(clock), _timespec_tonanos(ts));
+  } else {
+    kprintf("%s %s\n", DescribeClockName(clock), _strerrno(errno));
+  }
+}
+
+int main(int argc, char *argv[]) {
+  show(CLOCK_REALTIME);
+  show(CLOCK_REALTIME_FAST);
+  show(CLOCK_REALTIME_PRECISE);
+  show(CLOCK_MONOTONIC);
+  show(CLOCK_MONOTONIC_RAW);
+  show(CLOCK_MONOTONIC_FAST);
+  show(CLOCK_MONOTONIC_PRECISE);
+  show(CLOCK_PROCESS_CPUTIME_ID);
+  show(CLOCK_THREAD_CPUTIME_ID);
+  show(CLOCK_PROF);
+  show(CLOCK_BOOTTIME);
+  show(CLOCK_REALTIME_ALARM);
+  show(CLOCK_BOOTTIME_ALARM);
+  show(CLOCK_TAI);
+  show(CLOCK_UPTIME);
+  show(CLOCK_UPTIME_PRECISE);
+  show(CLOCK_UPTIME_FAST);
+  show(CLOCK_SECOND);
+}
diff --git a/libc/assert.h b/libc/assert.h
index ce6933b2a..5850a574f 100644
--- a/libc/assert.h
+++ b/libc/assert.h
@@ -7,16 +7,29 @@ extern bool __assert_disable;
 void __assert_fail(const char *, const char *, int) hidden relegated;
 
 #ifdef NDEBUG
-#define assert(EXPR) ((void)0)
+#define assert(x) ((void)0)
 #else
-#define assert(EXPR) \
-  ((void)((EXPR) || (__assert_fail(#EXPR, __FILE__, __LINE__), 0)))
+#define assert(x) ((void)((x) || (__assert_fail(#x, __FILE__, __LINE__), 0)))
 #endif
 
 #ifndef __cplusplus
 #define static_assert _Static_assert
 #endif
 
+#define _unassert(x)                 \
+  do {                               \
+    if (__builtin_expect(!(x), 0)) { \
+      unreachable;                   \
+    }                                \
+  } while (0)
+
+#define _npassert(x)                 \
+  do {                               \
+    if (__builtin_expect(!(x), 0)) { \
+      notpossible;                   \
+    }                                \
+  } while (0)
+
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
 #endif /* COSMOPOLITAN_LIBC_ASSERT_H_ */
diff --git a/libc/calls/chdir-nt.c b/libc/calls/chdir-nt.c
index 75a3e0ad0..18e1bc0f0 100644
--- a/libc/calls/chdir-nt.c
+++ b/libc/calls/chdir-nt.c
@@ -26,35 +26,36 @@
 #include "libc/nt/synchronization.h"
 #include "libc/sysv/errfuns.h"
 
-textwindows int sys_chdir_nt(const char *path) {
+textwindows int sys_chdir_nt_impl(char16_t path[hasatleast PATH_MAX],
+                                  uint32_t len) {
   uint32_t n;
-  int e, ms, err, len;
-  char16_t path16[PATH_MAX], var[4];
-  if ((len = __mkntpath(path, path16)) == -1) return -1;
-  if (!len) return enoent();
-  if (len && path16[len - 1] != u'\\') {
+  int e, ms, err;
+  char16_t var[4];
+
+  if (len && path[len - 1] != u'\\') {
     if (len + 2 > PATH_MAX) return enametoolong();
-    path16[len + 0] = u'\\';
-    path16[len + 1] = u'\0';
+    path[len + 0] = u'\\';
+    path[len + 1] = u'\0';
   }
+
   /*
    * chdir() seems flaky on windows 7
    * in a similar way to rmdir() sigh
    */
   for (err = errno, ms = 1;; ms *= 2) {
-    if (SetCurrentDirectory(path16)) {
+    if (SetCurrentDirectory(path)) {
       /*
        * Now we need to set a magic environment variable.
        */
-      if ((n = GetCurrentDirectory(ARRAYLEN(path16), path16))) {
-        if (n < ARRAYLEN(path16)) {
-          if (!((path16[0] == '/' && path16[1] == '/') ||
-                (path16[0] == '\\' && path16[1] == '\\'))) {
+      if ((n = GetCurrentDirectory(PATH_MAX, path))) {
+        if (n < PATH_MAX) {
+          if (!((path[0] == '/' && path[1] == '/') ||
+                (path[0] == '\\' && path[1] == '\\'))) {
             var[0] = '=';
-            var[1] = path16[0];
+            var[1] = path[0];
             var[2] = ':';
             var[3] = 0;
-            if (!SetEnvironmentVariable(var, path16)) {
+            if (!SetEnvironmentVariable(var, path)) {
               return __winerr();
             }
           }
@@ -77,5 +78,13 @@ textwindows int sys_chdir_nt(const char *path) {
       }
     }
   }
-  return __fix_enotdir(-1, path16);
+  return __fix_enotdir(-1, path);
+}
+
+textwindows int sys_chdir_nt(const char *path) {
+  int len;
+  char16_t path16[PATH_MAX];
+  if ((len = __mkntpath(path, path16)) == -1) return -1;
+  if (!len) return enoent();
+  return sys_chdir_nt_impl(path16, len);
 }
diff --git a/libc/calls/dup-nt.c b/libc/calls/dup-nt.c
index 598056055..d6add874f 100644
--- a/libc/calls/dup-nt.c
+++ b/libc/calls/dup-nt.c
@@ -16,6 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/assert.h"
 #include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
 #include "libc/calls/state.internal.h"
@@ -32,10 +33,9 @@
  */
 textwindows int sys_dup_nt(int oldfd, int newfd, int flags, int start) {
   int64_t rc, proc, handle;
-
-  // validate the api usage
-  if (oldfd < 0) return ebadf();
-  if (flags & ~O_CLOEXEC) return einval();
+  _unassert(oldfd >= 0);
+  _unassert(newfd >= -1);
+  _unassert(!(flags & ~O_CLOEXEC));
 
   __fds_lock();
 
diff --git a/libc/calls/dup3-sysv.c b/libc/calls/dup3-sysv.c
index 7ac62b1fe..842284992 100644
--- a/libc/calls/dup3-sysv.c
+++ b/libc/calls/dup3-sysv.c
@@ -16,41 +16,52 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/intrin/strace.internal.h"
+#include "libc/assert.h"
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/calls/syscall_support-sysv.internal.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
+#include "libc/intrin/strace.internal.h"
 #include "libc/sysv/consts/o.h"
 #include "libc/sysv/errfuns.h"
+#include "libc/thread/thread.h"
 
 #define F_DUP2FD         10
 #define F_DUP2FD_CLOEXEC 18
 
-int32_t sys_dup3(int32_t oldfd, int32_t newfd, int flags) {
-  static bool once;
-  static bool demodernize;
-  int olderr, how, fd;
-  if (!once) {
-    olderr = errno;
-    fd = __sys_dup3(oldfd, newfd, flags);
-    if (fd == -1 && errno == ENOSYS) {
-      STRACE("demodernizing %s() due to %s", "dup3", "RHEL5:CVE-2010-3301");
-      demodernize = true;
-      once = true;
-      errno = olderr;
-    } else {
-      once = true;
-      return fd;
-    }
-  } else if (!demodernize) {
-    return __sys_dup3(oldfd, newfd, flags);
+static struct Dup3 {
+  pthread_once_t once;
+  bool demodernize;
+} g_dup3;
+
+static void sys_dup3_test(void) {
+  int e = errno;
+  __sys_dup3(-1, -1, 0);
+  if ((g_dup3.demodernize = errno == ENOSYS)) {
+    STRACE("demodernizing %s() due to %s", "dup3", "ENOSYS");
   }
-  if (oldfd == newfd) return einval();
-  if (flags & ~O_CLOEXEC) return einval();
+  errno = e;
+}
+
+int32_t sys_dup3(int32_t oldfd, int32_t newfd, int flags) {
+  int how;
+  _unassert(oldfd >= 0);
+  _unassert(newfd >= 0);
+  _unassert(!(flags & ~O_CLOEXEC));
+
   if (IsFreebsd()) {
-    how = flags & O_CLOEXEC ? F_DUP2FD_CLOEXEC : F_DUP2FD;
+    if (flags & O_CLOEXEC) {
+      how = F_DUP2FD_CLOEXEC;
+    } else {
+      how = F_DUP2FD;
+    }
     return __sys_fcntl(oldfd, how, newfd);
+  }
+
+  pthread_once(&g_dup3.once, sys_dup3_test);
+
+  if (!g_dup3.demodernize) {
+    return __sys_dup3(oldfd, newfd, flags);
   } else {
     return __fixupnewfd(sys_dup2(oldfd, newfd), flags);
   }
diff --git a/libc/calls/dup3.c b/libc/calls/dup3.c
index 1f487f096..c06b175d7 100644
--- a/libc/calls/dup3.c
+++ b/libc/calls/dup3.c
@@ -18,10 +18,11 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
-#include "libc/intrin/strace.internal.h"
 #include "libc/calls/syscall-nt.internal.h"
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/dce.h"
+#include "libc/intrin/strace.internal.h"
+#include "libc/sysv/consts/o.h"
 #include "libc/sysv/errfuns.h"
 
 /**
@@ -46,14 +47,14 @@
  */
 int dup3(int oldfd, int newfd, int flags) {
   int rc;
-  if (__isfdkind(oldfd, kFdZip)) {
+  if (oldfd == newfd || (flags & ~O_CLOEXEC)) {
+    rc = einval();  // NetBSD doesn't do this
+  } else if (oldfd < 0 || newfd < 0) {
+    rc = ebadf();
+  } else if (__isfdkind(oldfd, kFdZip)) {
     rc = eopnotsupp();
-  } else if (oldfd == newfd) {
-    rc = einval();
   } else if (!IsWindows()) {
     rc = sys_dup3(oldfd, newfd, flags);
-  } else if (newfd < 0) {
-    rc = ebadf();
   } else {
     rc = sys_dup_nt(oldfd, newfd, flags, -1);
   }
diff --git a/libc/calls/fchdir-nt.c b/libc/calls/fchdir-nt.c
index f01d804b3..0a5956de3 100644
--- a/libc/calls/fchdir-nt.c
+++ b/libc/calls/fchdir-nt.c
@@ -23,20 +23,12 @@
 #include "libc/nt/files.h"
 #include "libc/sysv/errfuns.h"
 
+int sys_chdir_nt_impl(char16_t[hasatleast PATH_MAX], uint32_t);
+
 textwindows int sys_fchdir_nt(int dirfd) {
-  uint32_t len;
   char16_t dir[PATH_MAX];
   if (!__isfdkind(dirfd, kFdFile)) return ebadf();
-  len = GetFinalPathNameByHandle(g_fds.p[dirfd].handle, dir, ARRAYLEN(dir),
-                                 kNtFileNameNormalized | kNtVolumeNameDos);
-  if (len + 1 + 1 > ARRAYLEN(dir)) return enametoolong();
-  if (dir[len - 1] != u'\\') {
-    dir[len + 0] = u'\\';
-    dir[len + 1] = u'\0';
-  }
-  if (SetCurrentDirectory(dir)) {
-    return 0;
-  } else {
-    return __winerr();
-  }
+  return sys_chdir_nt_impl(
+      dir, GetFinalPathNameByHandle(g_fds.p[dirfd].handle, dir, ARRAYLEN(dir),
+                                    kNtFileNameNormalized | kNtVolumeNameDos));
 }
diff --git a/libc/calls/fcntl-nt.c b/libc/calls/fcntl-nt.c
index 9ddd29789..10a7a83ad 100644
--- a/libc/calls/fcntl-nt.c
+++ b/libc/calls/fcntl-nt.c
@@ -24,42 +24,47 @@
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/calls/wincrash.internal.h"
 #include "libc/errno.h"
-#include "libc/intrin/cmpxchg.h"
-#include "libc/macros.internal.h"
-#include "libc/nt/createfile.h"
-#include "libc/nt/enum/accessmask.h"
-#include "libc/nt/enum/fileflagandattributes.h"
+#include "libc/intrin/weaken.h"
+#include "libc/log/backtrace.internal.h"
 #include "libc/nt/enum/filelockflags.h"
-#include "libc/nt/enum/filesharemode.h"
-#include "libc/nt/enum/formatmessageflags.h"
 #include "libc/nt/errors.h"
 #include "libc/nt/files.h"
-#include "libc/nt/process.h"
 #include "libc/nt/runtime.h"
 #include "libc/nt/struct/byhandlefileinformation.h"
 #include "libc/nt/struct/overlapped.h"
-#include "libc/nt/synchronization.h"
 #include "libc/sysv/consts/f.h"
 #include "libc/sysv/consts/fd.h"
 #include "libc/sysv/consts/o.h"
 #include "libc/sysv/errfuns.h"
 
+bool __force_sqlite_to_work_until_we_can_fix_it;
+
 static textwindows int sys_fcntl_nt_dupfd(int fd, int cmd, int start) {
+  if (start < 0) return einval();
   return sys_dup_nt(fd, -1, (cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0), start);
 }
 
 static textwindows int sys_fcntl_nt_lock(struct Fd *f, int cmd, uintptr_t arg) {
+  int e;
   struct flock *l;
   uint32_t flags, err;
-  struct NtOverlapped ov;
   int64_t pos, off, len, size;
   struct NtByHandleFileInformation info;
-  if (!GetFileInformationByHandle(f->handle, &info)) return __winerr();
-  if (!SetFilePointerEx(f->handle, 0, &pos, SEEK_CUR)) return __winerr();
+
+  if (!GetFileInformationByHandle(f->handle, &info)) {
+    return __winerr();
+  }
+
+  pos = 0;
+  if (!SetFilePointerEx(f->handle, 0, &pos, SEEK_CUR)) {
+    return __winerr();
+  }
+
   l = (struct flock *)arg;
   len = l->l_len;
   off = l->l_start;
   size = (uint64_t)info.nFileSizeHigh << 32 | info.nFileSizeLow;
+
   switch (l->l_whence) {
     case SEEK_SET:
       break;
@@ -72,37 +77,60 @@ static textwindows int sys_fcntl_nt_lock(struct Fd *f, int cmd, uintptr_t arg) {
     default:
       return einval();
   }
-  if (!len) len = size - off;
-  if (off < 0 || len < 0) return einval();
-  _offset2overlap(f->handle, off, &ov);
-  if (l->l_type == F_RDLCK || l->l_type == F_WRLCK) {
-    flags = 0;
-    if (cmd == F_SETLK) flags |= kNtLockfileFailImmediately;
-    /* TODO: How can we make SQLite locks on Windows to work? */
-    /* if (l->l_type == F_WRLCK) flags |= kNtLockfileExclusiveLock; */
-    if (LockFileEx(f->handle, flags, 0, len, len >> 32, &ov)) {
-      return 0;
-    } else {
-      err = GetLastError();
-      if (err == kNtErrorLockViolation) err = EAGAIN;
-      errno = err;
-      return -1;
-    }
-  } else if (l->l_type == F_UNLCK) {
-    if (UnlockFileEx(f->handle, 0, len, len >> 32, &ov)) {
-      return 0;
-    } else {
-      err = GetLastError();
-      if (err == kNtErrorNotLocked) {
-        return 0;
-      } else {
-        errno = err;
-        return -1;
-      }
-    }
-  } else {
+
+  if (!len) {
+    len = size - off;
+  }
+
+  if (off < 0 || len < 0) {
     return einval();
   }
+
+  bool32 ok;
+  struct NtOverlapped ov = {.hEvent = f->handle,
+                            .Pointer = (void *)(uintptr_t)off};
+
+  if (l->l_type == F_RDLCK || l->l_type == F_WRLCK) {
+    flags = 0;
+    if (cmd != F_SETLKW) {
+      flags |= kNtLockfileFailImmediately;
+    }
+    if (l->l_type == F_WRLCK) {
+      flags |= kNtLockfileExclusiveLock;
+    }
+    ok = LockFileEx(f->handle, flags, 0, len, len >> 32, &ov);
+    if (cmd == F_GETLK) {
+      if (ok) {
+        l->l_type = F_UNLCK;
+        if (!UnlockFileEx(f->handle, 0, len, len >> 32, &ov)) {
+          notpossible;
+        }
+      } else {
+        l->l_pid = -1;
+        ok = true;
+      }
+    }
+    if (ok || __force_sqlite_to_work_until_we_can_fix_it) {
+      return 0;
+    } else {
+      return -1;
+    }
+  }
+
+  if (l->l_type == F_UNLCK) {
+    if (cmd == F_GETLK) return einval();
+    e = errno;
+    if (UnlockFileEx(f->handle, 0, len, len >> 32, &ov)) {
+      return 0;
+    } else if (errno == ENOLCK) {
+      errno = e;
+      return 0;
+    } else {
+      return 0;
+    }
+  }
+
+  return einval();
 }
 
 textwindows int sys_fcntl_nt(int fd, int cmd, uintptr_t arg) {
diff --git a/libc/calls/fcntl-sysv.c b/libc/calls/fcntl-sysv.c
index 66b398274..2cfbf8d0c 100644
--- a/libc/calls/fcntl-sysv.c
+++ b/libc/calls/fcntl-sysv.c
@@ -20,12 +20,14 @@
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/calls/syscall_support-sysv.internal.h"
 #include "libc/dce.h"
+#include "libc/errno.h"
 #include "libc/intrin/asan.internal.h"
 #include "libc/sysv/consts/f.h"
+#include "libc/sysv/consts/o.h"
 #include "libc/sysv/errfuns.h"
 
 int sys_fcntl(int fd, int cmd, uintptr_t arg) {
-  int rc;
+  int e, rc;
   bool islock;
   if ((islock = cmd == F_GETLK ||  //
                 cmd == F_SETLK ||  //
@@ -37,9 +39,13 @@ int sys_fcntl(int fd, int cmd, uintptr_t arg) {
     }
     cosmo2flock(arg);
   }
+  e = errno;
   rc = __sys_fcntl(fd, cmd, arg);
   if (islock) {
     flock2cosmo(arg);
+  } else if (rc == -1 && cmd == F_DUPFD_CLOEXEC && errno == EINVAL) {
+    errno = e;
+    rc = __fixupnewfd(__sys_fcntl(fd, F_DUPFD, arg), O_CLOEXEC);
   }
   return rc;
 }
diff --git a/libc/calls/fcntl.c b/libc/calls/fcntl.c
index 7bc3d0a04..62bb12415 100644
--- a/libc/calls/fcntl.c
+++ b/libc/calls/fcntl.c
@@ -37,11 +37,9 @@
  *     CHECK_GE((newfd = fcntl(oldfd, F_DUPFD,         3)), 3);
  *     CHECK_GE((newfd = fcntl(oldfd, F_DUPFD_CLOEXEC, 3)), 3);
  *
- * This function implements POSIX Advisory Locks, e.g.
- *
- *     CHECK_NE(-1, fcntl(zfd, F_SETLKW, &(struct flock){F_WRLCK}));
- *     // ...
- *     CHECK_NE(-1, fcntl(zfd, F_SETLK, &(struct flock){F_UNLCK}));
+ * This function implements POSIX Advisory Locks, which let independent
+ * processes (and on Windows, threads too!) read/write lock byte ranges
+ * of files. See `test/libc/calls/lock_test.c` for an example.
  *
  * Please be warned that locks currently do nothing on Windows since
  * figuring out how to polyfill them correctly is a work in progress.
diff --git a/libc/calls/fixupnewfd.c b/libc/calls/fixupnewfd.c
index 93911893a..36f234f79 100644
--- a/libc/calls/fixupnewfd.c
+++ b/libc/calls/fixupnewfd.c
@@ -16,19 +16,19 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/assert.h"
 #include "libc/calls/syscall-sysv.internal.h"
+#include "libc/calls/syscall_support-sysv.internal.h"
 #include "libc/sysv/consts/f.h"
 #include "libc/sysv/consts/fd.h"
 #include "libc/sysv/consts/o.h"
 
-/**
- * Applies file descriptor fixups on XNU or old Linux.
- * @see __fixupnewsockfd() for socket file descriptors
- */
+// Applies file descriptor fixups on XNU or old Linux.
+// See __fixupnewsockfd() for socket file descriptors.
 int __fixupnewfd(int fd, int flags) {
   if (fd != -1) {
     if (flags & O_CLOEXEC) {
-      __sys_fcntl(fd, F_SETFD, FD_CLOEXEC);
+      _npassert(!__sys_fcntl(fd, F_SETFD, FD_CLOEXEC));
     }
   }
   return fd;
diff --git a/libc/calls/flock-nt.c b/libc/calls/flock-nt.c
index 764905d20..4a04890d5 100644
--- a/libc/calls/flock-nt.c
+++ b/libc/calls/flock-nt.c
@@ -17,28 +17,49 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/internal.h"
+#include "libc/calls/struct/fd.internal.h"
+#include "libc/calls/syscall-nt.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
+#include "libc/nt/enum/filelockflags.h"
 #include "libc/nt/files.h"
-#include "libc/nt/runtime.h"
 #include "libc/nt/struct/byhandlefileinformation.h"
 #include "libc/nt/struct/overlapped.h"
-#include "libc/str/str.h"
-#include "libc/sysv/consts/lock.h"
 #include "libc/sysv/errfuns.h"
 
+#define _LOCK_SH 0
+#define _LOCK_EX kNtLockfileExclusiveLock
+#define _LOCK_NB kNtLockfileFailImmediately
+#define _LOCK_UN 8
+
 textwindows int sys_flock_nt(int fd, int op) {
-  struct NtOverlapped ov;
+  int64_t h;
   struct NtByHandleFileInformation info;
   if (!__isfdkind(fd, kFdFile)) return ebadf();
-  bzero(&ov, sizeof(ov));
-  if (GetFileInformationByHandle(g_fds.p[fd].handle, &info) &&
-      ((!(op & LOCK_UN) &&
-        LockFileEx(g_fds.p[fd].handle, op, 0, info.nFileSizeLow,
-                   info.nFileSizeHigh, &ov)) ||
-       ((op & LOCK_UN) && UnlockFileEx(g_fds.p[fd].handle, 0, info.nFileSizeLow,
-                                       info.nFileSizeHigh, &ov)))) {
-    return 0;
-  } else {
+  h = g_fds.p[fd].handle;
+  struct NtOverlapped ov = {.hEvent = h};
+
+  if (!GetFileInformationByHandle(h, &info)) {
     return __winerr();
   }
+
+  if (op & _LOCK_UN) {
+    if (op & ~_LOCK_UN) {
+      return einval();
+    }
+    if (UnlockFileEx(h, 0, info.nFileSizeLow, info.nFileSizeHigh, &ov)) {
+      return 0;
+    } else {
+      return -1;
+    }
+  }
+
+  if (op & ~(_LOCK_SH | _LOCK_EX | _LOCK_NB)) {
+    return einval();
+  }
+
+  if (LockFileEx(h, op, 0, info.nFileSizeLow, info.nFileSizeHigh, &ov)) {
+    return 0;
+  } else {
+    return -1;
+  }
 }
diff --git a/libc/calls/pipe2-sysv.c b/libc/calls/pipe2-sysv.c
index 526917b8b..9f890e036 100644
--- a/libc/calls/pipe2-sysv.c
+++ b/libc/calls/pipe2-sysv.c
@@ -24,16 +24,18 @@
 #include "libc/sysv/errfuns.h"
 
 int32_t sys_pipe2(int pipefd[hasatleast 2], unsigned flags) {
-  int rc, olderr;
+  int e, rc;
   if (!flags) goto OldSkool;
-  olderr = errno;
+  e = errno;
   rc = __sys_pipe2(pipefd, flags);
   if (rc == -1 && errno == ENOSYS) {
-    errno = olderr;
+    errno = e;
   OldSkool:
     if ((rc = sys_pipe(pipefd)) != -1) {
-      __fixupnewfd(pipefd[0], flags);
-      __fixupnewfd(pipefd[1], flags);
+      if (flags) {
+        __fixupnewfd(pipefd[0], flags);
+        __fixupnewfd(pipefd[1], flags);
+      }
     }
   }
   return rc;
diff --git a/libc/calls/pread.c b/libc/calls/pread.c
index 951f2f05a..6b79f8315 100644
--- a/libc/calls/pread.c
+++ b/libc/calls/pread.c
@@ -46,8 +46,11 @@
  */
 ssize_t pread(int fd, void *buf, size_t size, int64_t offset) {
   ssize_t rc;
-  if (fd == -1 || offset < 0) return einval();
-  if (IsAsan() && !__asan_is_valid(buf, size)) {
+  if (offset < 0) {
+    rc = einval();
+  } else if (fd < 0) {
+    rc = ebadf();
+  } else if (IsAsan() && !__asan_is_valid(buf, size)) {
     rc = efault();
   } else if (__isfdkind(fd, kFdZip)) {
     rc = _weaken(__zipos_read)(
@@ -60,7 +63,7 @@ ssize_t pread(int fd, void *buf, size_t size, int64_t offset) {
   } else {
     rc = ebadf();
   }
-  assert(rc == -1 || (size_t)rc <= size);
+  _npassert(rc == -1 || (size_t)rc <= size);
   DATATRACE("pread(%d, [%#.*hhs%s], %'zu, %'zd) → %'zd% m", fd,
             MAX(0, MIN(40, rc)), buf, rc > 40 ? "..." : "", size, offset, rc);
   return rc;
diff --git a/libc/calls/preadv.c b/libc/calls/preadv.c
index 93b7a4b4f..2d85c355d 100644
--- a/libc/calls/preadv.c
+++ b/libc/calls/preadv.c
@@ -16,91 +16,104 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/calls/calls.h"
+#include "libc/assert.h"
 #include "libc/calls/internal.h"
-#include "libc/calls/state.internal.h"
 #include "libc/calls/struct/iovec.h"
 #include "libc/calls/struct/iovec.internal.h"
+#include "libc/calls/struct/sigset.h"
+#include "libc/calls/struct/sigset.internal.h"
 #include "libc/calls/syscall-sysv.internal.h"
+#include "libc/calls/syscall_support-sysv.internal.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
 #include "libc/intrin/asan.internal.h"
-#include "libc/intrin/bits.h"
-#include "libc/intrin/describeflags.internal.h"
 #include "libc/intrin/kprintf.h"
 #include "libc/intrin/likely.h"
 #include "libc/intrin/strace.internal.h"
 #include "libc/intrin/weaken.h"
-#include "libc/macros.internal.h"
-#include "libc/sysv/consts/iov.h"
+#include "libc/sysv/consts/sig.h"
 #include "libc/sysv/errfuns.h"
 #include "libc/zipos/zipos.internal.h"
 
 static ssize_t Preadv(int fd, struct iovec *iov, int iovlen, int64_t off) {
-  static bool once, demodernize;
-  int i, err;
-  ssize_t rc;
-  size_t got, toto;
+  int e, i;
+  size_t got;
+  bool masked;
+  ssize_t rc, toto;
+  sigset_t mask, oldmask;
+
+  if (fd < 0) {
+    return ebadf();
+  }
+
+  if (iovlen < 0) {
+    return einval();
+  }
+
+  if (IsAsan() && !__asan_is_valid_iov(iov, iovlen)) {
+    return efault();
+  }
 
-  if (fd < 0) return einval();
-  if (iovlen < 0) return einval();
-  if (IsAsan() && !__asan_is_valid_iov(iov, iovlen)) return efault();
   if (fd < g_fds.n && g_fds.p[fd].kind == kFdZip) {
     return _weaken(__zipos_read)(
         (struct ZiposHandle *)(intptr_t)g_fds.p[fd].handle, iov, iovlen, off);
-  } else if (IsWindows()) {
+  }
+
+  if (IsMetal()) {
+    return espipe();  // must be serial or console if not zipos
+  }
+
+  if (IsWindows()) {
     if (fd < g_fds.n) {
       return sys_read_nt(g_fds.p + fd, iov, iovlen, off);
     } else {
       return ebadf();
     }
-  } else if (IsMetal()) {
-    return enosys();
   }
 
-  if (iovlen == 1) {
-    return sys_pread(fd, iov[0].iov_base, iov[0].iov_len, off, off);
-  }
-
-  /*
-   * NT, 2018-era XNU, and 2007-era Linux don't support this system call
-   */
-  if (!__vforked && !once) {
-    err = errno;
-    rc = sys_preadv(fd, iov, iovlen, off, off);
-    if (rc == -1 && errno == ENOSYS) {
-      errno = err;
-      once = true;
-      demodernize = true;
-      STRACE("demodernizing %s() due to %s", "preadv", "ENOSYS");
-    } else {
-      once = true;
-      return rc;
-    }
-  }
-
-  if (!demodernize) {
-    return sys_preadv(fd, iov, iovlen, off, off);
+  while (iovlen && !iov->iov_len) {
+    --iovlen;
+    ++iov;
   }
 
   if (!iovlen) {
-    return sys_pread(fd, NULL, 0, off, off);
+    return sys_pread(fd, 0, 0, off, off);
   }
 
+  if (iovlen == 1) {
+    return sys_pread(fd, iov->iov_base, iov->iov_len, off, off);
+  }
+
+  e = errno;
+  rc = sys_preadv(fd, iov, iovlen, off, off);
+  if (rc != -1 || errno != ENOSYS) return rc;
+  errno = e;
+
   for (toto = i = 0; i < iovlen; ++i) {
     rc = sys_pread(fd, iov[i].iov_base, iov[i].iov_len, off, off);
     if (rc == -1) {
-      if (toto && (errno == EINTR || errno == EAGAIN)) {
-        return toto;
-      } else {
-        return -1;
+      if (!toto) {
+        toto = -1;
       }
+      break;
     }
+
     got = rc;
     toto += got;
+    off += got;
     if (got != iov[i].iov_len) {
       break;
     }
+
+    if (!masked) {
+      sigfillset(&mask);
+      _npassert(!sys_sigprocmask(SIG_SETMASK, &mask, &oldmask));
+      masked = true;
+    }
+  }
+
+  if (masked) {
+    _npassert(!sys_sigprocmask(SIG_SETMASK, &oldmask, 0));
   }
 
   return toto;
diff --git a/libc/calls/pwrite.c b/libc/calls/pwrite.c
index 779ab96a4..2d9c7d561 100644
--- a/libc/calls/pwrite.c
+++ b/libc/calls/pwrite.c
@@ -19,12 +19,12 @@
 #include "libc/assert.h"
 #include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
-#include "libc/intrin/strace.internal.h"
 #include "libc/calls/struct/iovec.h"
 #include "libc/calls/struct/iovec.internal.h"
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/dce.h"
 #include "libc/intrin/asan.internal.h"
+#include "libc/intrin/strace.internal.h"
 #include "libc/macros.internal.h"
 #include "libc/sysv/errfuns.h"
 
@@ -46,9 +46,11 @@
 ssize_t pwrite(int fd, const void *buf, size_t size, int64_t offset) {
   ssize_t rc;
   size_t wrote;
-  if (fd == -1 || offset < 0) return einval();
-  size = MIN(size, 0x7ffff000);
-  if (IsAsan() && !__asan_is_valid(buf, size)) {
+  if (offset < 0) {
+    rc = einval();
+  } else if (fd == -1) {
+    rc = ebadf();
+  } else if (IsAsan() && !__asan_is_valid(buf, size)) {
     rc = efault();
   } else if (!IsWindows()) {
     rc = sys_pwrite(fd, buf, size, offset, offset);
@@ -59,10 +61,10 @@ ssize_t pwrite(int fd, const void *buf, size_t size, int64_t offset) {
   }
   if (rc != -1) {
     wrote = (size_t)rc;
-    if (wrote == 0) {
-      assert(size == 0);
+    if (!wrote) {
+      _npassert(size == 0);
     } else {
-      assert(wrote <= size);
+      _npassert(wrote <= size);
     }
   }
   DATATRACE("pwrite(%d, %#.*hhs%s, %'zu, %'zd) → %'zd% m", fd,
diff --git a/libc/calls/pwritev.c b/libc/calls/pwritev.c
index 9387a720b..afa626d0f 100644
--- a/libc/calls/pwritev.c
+++ b/libc/calls/pwritev.c
@@ -16,90 +16,105 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/calls/calls.h"
+#include "libc/assert.h"
 #include "libc/calls/internal.h"
 #include "libc/calls/struct/iovec.h"
 #include "libc/calls/struct/iovec.internal.h"
+#include "libc/calls/struct/sigset.h"
+#include "libc/calls/struct/sigset.internal.h"
 #include "libc/calls/syscall-sysv.internal.h"
+#include "libc/calls/syscall_support-sysv.internal.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
 #include "libc/intrin/asan.internal.h"
-#include "libc/intrin/describeflags.internal.h"
 #include "libc/intrin/kprintf.h"
 #include "libc/intrin/likely.h"
 #include "libc/intrin/strace.internal.h"
 #include "libc/intrin/weaken.h"
-#include "libc/macros.internal.h"
-#include "libc/sysv/consts/iov.h"
+#include "libc/sysv/consts/sig.h"
 #include "libc/sysv/errfuns.h"
 #include "libc/zipos/zipos.internal.h"
 
 static ssize_t Pwritev(int fd, const struct iovec *iov, int iovlen,
                        int64_t off) {
-  static bool once, demodernize;
-  int i, err;
-  ssize_t rc;
-  size_t sent, toto;
+  int i, e;
+  bool masked;
+  size_t sent;
+  ssize_t rc, toto;
+  sigset_t mask, oldmask;
+
+  if (fd < 0) {
+    return ebadf();
+  }
+
+  if (iovlen < 0) {
+    return einval();
+  }
+
+  if (IsAsan() && !__asan_is_valid_iov(iov, iovlen)) {
+    return efault();
+  }
 
-  if (fd < 0) return einval();
-  if (iovlen < 0) return einval();
-  if (IsAsan() && !__asan_is_valid_iov(iov, iovlen)) return efault();
   if (fd < g_fds.n && g_fds.p[fd].kind == kFdZip) {
     return _weaken(__zipos_write)(
         (struct ZiposHandle *)(intptr_t)g_fds.p[fd].handle, iov, iovlen, off);
-  } else if (IsWindows()) {
+  }
+
+  if (IsWindows()) {
     if (fd < g_fds.n) {
       return sys_write_nt(fd, iov, iovlen, off);
     } else {
       return ebadf();
     }
-  } else if (IsMetal()) {
-    return enosys();
   }
 
-  if (iovlen == 1) {
-    return sys_pwrite(fd, iov[0].iov_base, iov[0].iov_len, off, off);
+  if (IsMetal()) {
+    return espipe();  // must be serial or console if not zipos
   }
 
-  /*
-   * NT, 2018-era XNU, and 2007-era Linux don't support this system call
-   */
-  if (!once) {
-    err = errno;
-    rc = sys_pwritev(fd, iov, iovlen, off, off);
-    if (rc == -1 && errno == ENOSYS) {
-      errno = err;
-      once = true;
-      demodernize = true;
-      STRACE("demodernizing %s() due to %s", "pwritev", "ENOSYS");
-    } else {
-      once = true;
-      return rc;
-    }
-  }
-
-  if (!demodernize) {
-    return sys_pwritev(fd, iov, iovlen, off, off);
+  while (iovlen && !iov->iov_len) {
+    --iovlen;
+    ++iov;
   }
 
   if (!iovlen) {
-    return sys_pwrite(fd, NULL, 0, off, off);
+    return sys_pwrite(fd, 0, 0, off, off);
   }
 
+  if (iovlen == 1) {
+    return sys_pwrite(fd, iov->iov_base, iov->iov_len, off, off);
+  }
+
+  e = errno;
+  rc = sys_pwritev(fd, iov, iovlen, off, off);
+  if (rc != -1 || errno != ENOSYS) return rc;
+  errno = e;
+
   for (toto = i = 0; i < iovlen; ++i) {
     rc = sys_pwrite(fd, iov[i].iov_base, iov[i].iov_len, off, off);
     if (rc == -1) {
-      if (toto && (errno == EINTR || errno == EAGAIN)) {
-        return toto;
-      } else {
-        return -1;
+      if (!toto) {
+        toto = -1;
       }
+      break;
     }
+
     sent = rc;
     toto += sent;
+    off += sent;
     if (sent != iov[i].iov_len) {
       break;
     }
+
+    if (!masked) {
+      sigfillset(&mask);
+      _npassert(!sys_sigprocmask(SIG_SETMASK, &mask, &oldmask));
+      masked = true;
+    }
+  }
+
+  if (masked) {
+    _npassert(!sys_sigprocmask(SIG_SETMASK, &oldmask, 0));
   }
 
   return toto;
diff --git a/libc/calls/read-nt.c b/libc/calls/read-nt.c
index 6afd415c3..c51fcd657 100644
--- a/libc/calls/read-nt.c
+++ b/libc/calls/read-nt.c
@@ -16,14 +16,16 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/assert.h"
+#include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
 #include "libc/calls/sig.internal.h"
-#include "libc/intrin/strace.internal.h"
 #include "libc/calls/struct/fd.internal.h"
 #include "libc/calls/struct/iovec.h"
 #include "libc/calls/struct/iovec.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/calls/wincrash.internal.h"
+#include "libc/intrin/strace.internal.h"
 #include "libc/nt/enum/filetype.h"
 #include "libc/nt/errors.h"
 #include "libc/nt/files.h"
@@ -35,8 +37,10 @@
 
 static textwindows ssize_t sys_read_nt_impl(struct Fd *fd, void *data,
                                             size_t size, ssize_t offset) {
+  int64_t p;
   uint32_t got, avail;
   struct NtOverlapped overlap;
+
   if (GetFileType(fd->handle) == kNtFileTypePipe) {
     for (;;) {
       if (!PeekNamedPipe(fd->handle, 0, 0, 0, &avail, 0)) break;
@@ -52,10 +56,20 @@ static textwindows ssize_t sys_read_nt_impl(struct Fd *fd, void *data,
     }
     POLLTRACE("sys_read_nt ready to read");
   }
+
+  if (offset != -1) {
+    // windows changes the file pointer even if overlapped is passed
+    _npassert(SetFilePointerEx(fd->handle, 0, &p, SEEK_CUR));
+  }
+
   if (ReadFile(fd->handle, data, _clampio(size), &got,
                _offset2overlap(fd->handle, offset, &overlap))) {
+    if (offset != -1) {
+      _npassert(SetFilePointerEx(fd->handle, p, 0, SEEK_SET));
+    }
     return got;
   }
+
   switch (GetLastError()) {
     case kNtErrorBrokenPipe:    // broken pipe
     case kNtErrorNoData:        // closing named pipe
@@ -73,6 +87,7 @@ textwindows ssize_t sys_read_nt(struct Fd *fd, const struct iovec *iov,
   ssize_t rc;
   uint32_t size;
   size_t i, total;
+  if (opt_offset < -1) return einval();
   if (_check_interrupts(true, fd)) return eintr();
   while (iovlen && !iov[0].iov_len) iov++, iovlen--;
   if (iovlen) {
diff --git a/libc/calls/sched-sysv.internal.h b/libc/calls/sched-sysv.internal.h
index 7da6db8f5..43026efde 100644
--- a/libc/calls/sched-sysv.internal.h
+++ b/libc/calls/sched-sysv.internal.h
@@ -18,7 +18,7 @@ int sys_sched_setscheduler(int, int, const struct sched_param *);
 int sys_sched_yield(void) hidden;
 int64_t sys_sched_getaffinity(int, uint64_t, void *) hidden;
 
-int sys_sched_getscheduler_netbsd(int);
+int sys_sched_getscheduler_netbsd(int, struct sched_param *);
 int sys_sched_setparam_netbsd(int, int, int, const struct sched_param *)  //
     asm("sys_sched_setparam");
 int sys_sched_getparam_netbsd(int, int, int *, struct sched_param *)  //
diff --git a/libc/calls/sched_getaffinity.c b/libc/calls/sched_getaffinity.c
index 9a2d3cd75..45a8e3071 100644
--- a/libc/calls/sched_getaffinity.c
+++ b/libc/calls/sched_getaffinity.c
@@ -16,11 +16,13 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/calls.h"
 #include "libc/calls/sched-sysv.internal.h"
-#include "libc/intrin/strace.internal.h"
 #include "libc/calls/struct/cpuset.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/dce.h"
+#include "libc/intrin/strace.internal.h"
+#include "libc/macros.internal.h"
 #include "libc/nt/process.h"
 #include "libc/nt/runtime.h"
 #include "libc/nt/thread.h"
@@ -52,7 +54,7 @@ static textwindows int sys_sched_getaffinity_nt(int tid, size_t size,
  * @param bitset receives bitset and should be uint64_t[16] in order to
  *     work on older versions of Linux
  * @return 0 on success, or -1 w/ errno
- * @raise ENOSYS on non-Linux
+ * @raise ENOSYS if not Linux, NetBSD, or Windows
  */
 int sched_getaffinity(int tid, size_t size, cpu_set_t *bitset) {
   int rc;
@@ -60,6 +62,12 @@ int sched_getaffinity(int tid, size_t size, cpu_set_t *bitset) {
     rc = einval();
   } else if (IsWindows()) {
     rc = sys_sched_getaffinity_nt(tid, size, bitset);
+  } else if (IsNetbsd()) {
+    if (!sys_sched_getaffinity_netbsd(0, tid, MIN(size, 32), bitset)) {
+      rc = MIN(size, 32);
+    } else {
+      rc = -1;
+    }
   } else {
     rc = sys_sched_getaffinity(tid, size, bitset);
   }
diff --git a/libc/calls/sched_getparam.c b/libc/calls/sched_getparam.c
index 85b91545b..049ce4a56 100644
--- a/libc/calls/sched_getparam.c
+++ b/libc/calls/sched_getparam.c
@@ -18,13 +18,31 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/sched-sysv.internal.h"
 #include "libc/calls/struct/sched_param.h"
+#include "libc/calls/struct/sched_param.internal.h"
+#include "libc/dce.h"
+#include "libc/intrin/asan.internal.h"
+#include "libc/intrin/strace.internal.h"
+#include "libc/sysv/errfuns.h"
 
 /**
  * Gets scheduler policy parameter.
  *
  * @return 0 on success, or -1 w/ errno
- * @raise ENOSYS on XNU, Windows
+ * @raise ENOSYS on XNU, Windows, OpenBSD
  */
 int sched_getparam(int pid, struct sched_param *param) {
-  return sys_sched_getparam(pid, param);
+  int rc;
+  struct sched_param p;
+  if (!param || (IsAsan() && !__asan_is_valid(param, sizeof(*param)))) {
+    rc = efault();
+  } else if (IsNetbsd()) {
+    if (!(rc = sys_sched_getscheduler_netbsd(pid, &p))) {
+      *param = p;
+    }
+  } else {
+    rc = sys_sched_getparam(pid, param);
+  }
+  STRACE("sched_getparam(%d, [%s]) → %d% m", pid, DescribeSchedParam(param),
+         rc);
+  return rc;
 }
diff --git a/libc/calls/sched_getscheduler-netbsd.c b/libc/calls/sched_getscheduler-netbsd.c
index 860acbc2b..bb89fabdf 100644
--- a/libc/calls/sched_getscheduler-netbsd.c
+++ b/libc/calls/sched_getscheduler-netbsd.c
@@ -20,10 +20,9 @@
 #include "libc/calls/sched-sysv.internal.h"
 #include "libc/calls/struct/sched_param.h"
 
-int sys_sched_getscheduler_netbsd(int pid) {
+int sys_sched_getscheduler_netbsd(int pid, struct sched_param *sp) {
   int policy;
-  struct sched_param sp;
-  if (sys_sched_getparam_netbsd(pid, P_ALL_LWPS, &policy, &sp) != -1) {
+  if (sys_sched_getparam_netbsd(pid, P_ALL_LWPS, &policy, sp) != -1) {
     return policy;
   } else {
     return -1;
diff --git a/libc/calls/sched_getscheduler.c b/libc/calls/sched_getscheduler.c
index 44d408604..4b1246125 100644
--- a/libc/calls/sched_getscheduler.c
+++ b/libc/calls/sched_getscheduler.c
@@ -17,10 +17,10 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/sched-sysv.internal.h"
-#include "libc/intrin/strace.internal.h"
 #include "libc/calls/struct/sched_param.h"
 #include "libc/dce.h"
 #include "libc/intrin/describeflags.internal.h"
+#include "libc/intrin/strace.internal.h"
 
 /**
  * Gets scheduler policy for `pid`.
@@ -40,7 +40,8 @@
 int sched_getscheduler(int pid) {
   int rc;
   if (IsNetbsd()) {
-    rc = sys_sched_getscheduler_netbsd(pid);
+    struct sched_param p;
+    rc = sys_sched_getscheduler_netbsd(pid, &p);
   } else {
     rc = sys_sched_getscheduler(pid);
   }
diff --git a/libc/calls/sched_setaffinity.c b/libc/calls/sched_setaffinity.c
index a45b8b3a0..4e56a7a24 100644
--- a/libc/calls/sched_setaffinity.c
+++ b/libc/calls/sched_setaffinity.c
@@ -18,13 +18,14 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
 #include "libc/calls/sched-sysv.internal.h"
-#include "libc/intrin/strace.internal.h"
 #include "libc/calls/struct/cpuset.h"
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/dce.h"
 #include "libc/intrin/safemacros.internal.h"
+#include "libc/intrin/strace.internal.h"
 #include "libc/limits.h"
+#include "libc/macros.internal.h"
 #include "libc/nt/enum/processaccess.h"
 #include "libc/nt/enum/threadaccess.h"
 #include "libc/nt/process.h"
@@ -34,14 +35,14 @@
 #include "libc/sysv/errfuns.h"
 
 static textwindows dontinline int sys_sched_setaffinity_nt(int pid,
-                                                           uint64_t bitsetsize,
+                                                           uint64_t size,
                                                            const void *bitset) {
   int rc;
-  uintptr_t mask;
   int64_t handle;
+  uintptr_t mask;
   typeof(SetThreadAffinityMask) *SetAffinityMask = SetThreadAffinityMask;
   mask = 0;
-  memcpy(&mask, bitset, min(bitsetsize, sizeof(uintptr_t)));
+  memcpy(&mask, bitset, min(size, sizeof(uintptr_t)));
   handle = 0;
   if (!pid) pid = GetCurrentThreadId();
   if (0 < pid && pid <= UINT32_MAX) {
@@ -69,19 +70,21 @@ static textwindows dontinline int sys_sched_setaffinity_nt(int pid,
  * Asks kernel to only schedule thread on particular CPUs.
  *
  * @param tid is the process or thread id (or 0 for caller)
- * @param bitsetsize is byte length of bitset, which should be 128
+ * @param size is byte length of bitset, which should be 128
  * @return 0 on success, or -1 w/ errno
- * @raise ENOSYS if not Linux or Windows
+ * @raise ENOSYS if not Linux, NetBSD, or Windows
  */
-int sched_setaffinity(int tid, size_t bitsetsize, const cpu_set_t *bitset) {
+int sched_setaffinity(int tid, size_t size, const cpu_set_t *bitset) {
   int rc;
-  if (bitsetsize != 128) {
+  if (size != 128) {
     rc = einval();
   } else if (IsWindows()) {
-    rc = sys_sched_setaffinity_nt(tid, bitsetsize, bitset);
+    rc = sys_sched_setaffinity_nt(tid, size, bitset);
+  } else if (IsNetbsd()) {
+    rc = sys_sched_setaffinity_netbsd(0, tid, MIN(size, 32), bitset);
   } else {
-    rc = sys_sched_setaffinity(tid, bitsetsize, bitset);
+    rc = sys_sched_setaffinity(tid, size, bitset);
   }
-  STRACE("sched_setaffinity(%d, %'zu, %p) → %d% m", tid, bitsetsize, bitset);
+  STRACE("sched_setaffinity(%d, %'zu, %p) → %d% m", tid, size, bitset);
   return rc;
 }
diff --git a/libc/calls/sched_setparam.c b/libc/calls/sched_setparam.c
index fcb31c091..565c071ba 100644
--- a/libc/calls/sched_setparam.c
+++ b/libc/calls/sched_setparam.c
@@ -18,11 +18,30 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/sched-sysv.internal.h"
 #include "libc/calls/struct/sched_param.h"
+#include "libc/calls/struct/sched_param.internal.h"
+#include "libc/dce.h"
+#include "libc/intrin/asan.internal.h"
+#include "libc/intrin/strace.internal.h"
+#include "libc/sysv/errfuns.h"
 
 /**
  * Sets scheduler policy parameter.
- * @raise ENOSYS on XNU, Windows
+ *
+ * @return 0 on success, or -1 w/ errno
+ * @raise ENOSYS on XNU, Windows, OpenBSD
  */
 int sched_setparam(int pid, const struct sched_param *param) {
-  return sys_sched_setparam(pid, param);
+  int rc, policy;
+  struct sched_param p;
+  if (!param || (IsAsan() && !__asan_is_valid(param, sizeof(*param)))) {
+    rc = efault();
+  } else if (IsNetbsd()) {
+    if ((rc = policy = sys_sched_getscheduler_netbsd(pid, &p)) != -1) {
+      rc = sys_sched_setparam_netbsd(pid, P_ALL_LWPS, policy, param);
+    }
+  } else {
+    rc = sys_sched_setparam(pid, param);
+  }
+  STRACE("sched_setparam(%d, %s) → %d% m", pid, DescribeSchedParam(param), rc);
+  return rc;
 }
diff --git a/libc/calls/sched_setscheduler.c b/libc/calls/sched_setscheduler.c
index 06fd7b43a..64e1fd2b4 100644
--- a/libc/calls/sched_setscheduler.c
+++ b/libc/calls/sched_setscheduler.c
@@ -17,14 +17,14 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/sched-sysv.internal.h"
-#include "libc/intrin/strace.internal.h"
 #include "libc/calls/struct/sched_param.h"
 #include "libc/calls/struct/sched_param.internal.h"
 #include "libc/dce.h"
 #include "libc/intrin/describeflags.internal.h"
-#include "libc/thread/tls.h"
+#include "libc/intrin/strace.internal.h"
 #include "libc/str/str.h"
 #include "libc/sysv/errfuns.h"
+#include "libc/thread/tls.h"
 
 /**
  * Sets scheduling policy of process, e.g.
@@ -94,9 +94,10 @@
  */
 int sched_setscheduler(int pid, int policy, const struct sched_param *param) {
   int rc, old;
+  struct sched_param p;
 
   if (IsNetbsd()) {
-    rc = sys_sched_getscheduler_netbsd(pid);
+    rc = sys_sched_getscheduler_netbsd(pid, &p);
   } else {
     rc = sys_sched_getscheduler(pid);
   }
diff --git a/libc/calls/write-nt.c b/libc/calls/write-nt.c
index 77f825d29..b7939ba28 100644
--- a/libc/calls/write-nt.c
+++ b/libc/calls/write-nt.c
@@ -16,6 +16,8 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/assert.h"
+#include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
 #include "libc/calls/sig.internal.h"
 #include "libc/calls/struct/iovec.h"
@@ -26,6 +28,7 @@
 #include "libc/intrin/strace.internal.h"
 #include "libc/intrin/weaken.h"
 #include "libc/nt/errors.h"
+#include "libc/nt/files.h"
 #include "libc/nt/runtime.h"
 #include "libc/runtime/internal.h"
 #include "libc/runtime/runtime.h"
@@ -35,12 +38,25 @@
 
 static textwindows ssize_t sys_write_nt_impl(int fd, void *data, size_t size,
                                              ssize_t offset) {
+  int64_t h, p;
   uint32_t err, sent;
   struct NtOverlapped overlap;
-  if (WriteFile(g_fds.p[fd].handle, data, _clampio(size), &sent,
-                _offset2overlap(g_fds.p[fd].handle, offset, &overlap))) {
+
+  h = g_fds.p[fd].handle;
+
+  if (offset != -1) {
+    // windows changes the file pointer even if overlapped is passed
+    _npassert(SetFilePointerEx(h, 0, &p, SEEK_CUR));
+  }
+
+  if (WriteFile(h, data, _clampio(size), &sent,
+                _offset2overlap(h, offset, &overlap))) {
+    if (offset != -1) {
+      _npassert(SetFilePointerEx(h, p, 0, SEEK_SET));
+    }
     return sent;
   }
+
   switch (GetLastError()) {
     // case kNtErrorInvalidHandle:
     //   return ebadf(); /* handled by consts.sh */
@@ -68,6 +84,7 @@ textwindows ssize_t sys_write_nt(int fd, const struct iovec *iov, size_t iovlen,
   size_t i, total;
   uint32_t size, wrote;
   struct NtOverlapped overlap;
+  if (opt_offset < -1) return einval();
   while (iovlen && !iov[0].iov_len) iov++, iovlen--;
   if (iovlen) {
     for (total = i = 0; i < iovlen; ++i) {
diff --git a/libc/fmt/bing.c b/libc/fmt/bing.c
index 86449e891..92eafdbf0 100644
--- a/libc/fmt/bing.c
+++ b/libc/fmt/bing.c
@@ -19,6 +19,7 @@
 #include "libc/assert.h"
 #include "libc/fmt/bing.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Turns binary octet into unicode glyph representation.
diff --git a/libc/fmt/stoa.c b/libc/fmt/stoa.c
index 4d87f7a38..6b6d02450 100644
--- a/libc/fmt/stoa.c
+++ b/libc/fmt/stoa.c
@@ -16,7 +16,6 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/assert.h"
 #include "libc/fmt/fmt.internal.h"
 #include "libc/fmt/internal.h"
 #include "libc/intrin/bits.h"
@@ -26,6 +25,7 @@
 #include "libc/intrin/weaken.h"
 #include "libc/str/str.h"
 #include "libc/str/strwidth.h"
+#include "libc/str/tab.internal.h"
 #include "libc/str/thompike.h"
 #include "libc/str/unicode.h"
 #include "libc/str/utf16.h"
diff --git a/libc/fmt/strtoi128.c b/libc/fmt/strtoi128.c
index ff9d6a317..c20acf08a 100644
--- a/libc/fmt/strtoi128.c
+++ b/libc/fmt/strtoi128.c
@@ -21,6 +21,7 @@
 #include "libc/fmt/strtol.internal.h"
 #include "libc/limits.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes 128-bit signed integer from ASCII string.
diff --git a/libc/fmt/strtoimax.c b/libc/fmt/strtoimax.c
index 7eacb3322..d91291ed0 100644
--- a/libc/fmt/strtoimax.c
+++ b/libc/fmt/strtoimax.c
@@ -21,6 +21,7 @@
 #include "libc/fmt/strtol.internal.h"
 #include "libc/limits.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes intmax_t from ASCII string.
diff --git a/libc/fmt/strtol.c b/libc/fmt/strtol.c
index 8fc107153..4094f6da2 100644
--- a/libc/fmt/strtol.c
+++ b/libc/fmt/strtol.c
@@ -21,6 +21,7 @@
 #include "libc/fmt/strtol.internal.h"
 #include "libc/limits.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes signed integer from ASCII string.
diff --git a/libc/fmt/strtou128.c b/libc/fmt/strtou128.c
index b8005fd18..1dd25cf88 100644
--- a/libc/fmt/strtou128.c
+++ b/libc/fmt/strtou128.c
@@ -19,6 +19,7 @@
 #include "libc/fmt/conv.h"
 #include "libc/fmt/strtol.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes 128-bit unsigned integer from ASCII string.
diff --git a/libc/fmt/strtoul.c b/libc/fmt/strtoul.c
index b9eaef49f..facc41c18 100644
--- a/libc/fmt/strtoul.c
+++ b/libc/fmt/strtoul.c
@@ -20,6 +20,7 @@
 #include "libc/fmt/conv.h"
 #include "libc/fmt/strtol.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes unsigned integer from ASCII string.
diff --git a/libc/fmt/strtoumax.c b/libc/fmt/strtoumax.c
index eb4e5134e..c1f41910c 100644
--- a/libc/fmt/strtoumax.c
+++ b/libc/fmt/strtoumax.c
@@ -19,6 +19,7 @@
 #include "libc/fmt/conv.h"
 #include "libc/fmt/strtol.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes uintmax_t from ASCII string.
diff --git a/libc/fmt/unbing.c b/libc/fmt/unbing.c
index 0de72eaa2..9bf2c6112 100644
--- a/libc/fmt/unbing.c
+++ b/libc/fmt/unbing.c
@@ -21,6 +21,7 @@
 #include "libc/nexgen32e/nexgen32e.h"
 #include "libc/runtime/runtime.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 static const int kCp437iMultimappings[] = {
     u'\n' << 8 | '\n',   // NEWLINE
diff --git a/libc/fmt/vcscanf.c b/libc/fmt/vcscanf.c
index c51d4044e..22aa93a26 100644
--- a/libc/fmt/vcscanf.c
+++ b/libc/fmt/vcscanf.c
@@ -23,6 +23,7 @@
 #include "libc/runtime/runtime.h"
 #include "libc/str/oldutf16.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/str/tpdecodecb.internal.h"
 #include "libc/str/utf16.h"
 #include "libc/sysv/errfuns.h"
diff --git a/libc/fmt/wcstoi128.c b/libc/fmt/wcstoi128.c
index 4bb79d338..3337ed488 100644
--- a/libc/fmt/wcstoi128.c
+++ b/libc/fmt/wcstoi128.c
@@ -21,6 +21,7 @@
 #include "libc/fmt/strtol.internal.h"
 #include "libc/limits.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes 128-bit signed integer from wide string.
diff --git a/libc/fmt/wcstoimax.c b/libc/fmt/wcstoimax.c
index b6abb147d..10bf752a1 100644
--- a/libc/fmt/wcstoimax.c
+++ b/libc/fmt/wcstoimax.c
@@ -21,6 +21,7 @@
 #include "libc/fmt/strtol.internal.h"
 #include "libc/limits.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes intmax_t from wide string.
diff --git a/libc/fmt/wcstol.c b/libc/fmt/wcstol.c
index e27dfd204..28562afb4 100644
--- a/libc/fmt/wcstol.c
+++ b/libc/fmt/wcstol.c
@@ -21,6 +21,7 @@
 #include "libc/fmt/strtol.internal.h"
 #include "libc/limits.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes signed long integer from wide string.
diff --git a/libc/fmt/wcstoll.c b/libc/fmt/wcstoll.c
index 4b63f8d55..6851237ed 100644
--- a/libc/fmt/wcstoll.c
+++ b/libc/fmt/wcstoll.c
@@ -21,6 +21,7 @@
 #include "libc/fmt/strtol.internal.h"
 #include "libc/limits.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes signed long long integer from wide string.
diff --git a/libc/fmt/wcstou128.c b/libc/fmt/wcstou128.c
index 38c74f8b2..2d2fa01d1 100644
--- a/libc/fmt/wcstou128.c
+++ b/libc/fmt/wcstou128.c
@@ -19,6 +19,7 @@
 #include "libc/fmt/conv.h"
 #include "libc/fmt/strtol.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes 128-bit unsigned integer from wide string.
diff --git a/libc/fmt/wcstoul.c b/libc/fmt/wcstoul.c
index 3a68c651a..6f2ddeef2 100644
--- a/libc/fmt/wcstoul.c
+++ b/libc/fmt/wcstoul.c
@@ -20,6 +20,7 @@
 #include "libc/fmt/conv.h"
 #include "libc/fmt/strtol.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes unsigned integer from wide string.
diff --git a/libc/fmt/wcstoull.c b/libc/fmt/wcstoull.c
index c17fe8605..73739c6ca 100644
--- a/libc/fmt/wcstoull.c
+++ b/libc/fmt/wcstoull.c
@@ -20,6 +20,7 @@
 #include "libc/fmt/conv.h"
 #include "libc/fmt/strtol.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes unsigned long long integer from wide string.
diff --git a/libc/fmt/wcstoumax.c b/libc/fmt/wcstoumax.c
index 80f720756..8fc617813 100644
--- a/libc/fmt/wcstoumax.c
+++ b/libc/fmt/wcstoumax.c
@@ -19,6 +19,7 @@
 #include "libc/fmt/conv.h"
 #include "libc/fmt/strtol.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Decodes uintmax_t from wide string.
diff --git a/libc/intrin/asan.c b/libc/intrin/asan.c
index dc1426b68..a1f001ca8 100644
--- a/libc/intrin/asan.c
+++ b/libc/intrin/asan.c
@@ -50,6 +50,7 @@
 #include "libc/runtime/stack.h"
 #include "libc/runtime/symbols.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/sysv/consts/auxv.h"
 #include "libc/sysv/consts/map.h"
 #include "libc/sysv/consts/nr.h"
diff --git a/libc/intrin/asan.internal.h b/libc/intrin/asan.internal.h
index eee7b4797..ad40b1a61 100644
--- a/libc/intrin/asan.internal.h
+++ b/libc/intrin/asan.internal.h
@@ -3,7 +3,6 @@
 #include "libc/calls/struct/iovec.h"
 #include "libc/intrin/asancodes.h"
 #include "libc/macros.internal.h"
-#include "libc/thread/thread.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
diff --git a/libc/intrin/describeflags.internal.h b/libc/intrin/describeflags.internal.h
index afb87b598..8ec3b0aa5 100644
--- a/libc/intrin/describeflags.internal.h
+++ b/libc/intrin/describeflags.internal.h
@@ -30,6 +30,7 @@ const char *DescribeNtFileFlagAttr(char[256], uint32_t);
 const char *DescribeNtFileMapFlags(char[64], uint32_t);
 const char *DescribeNtFileShareFlags(char[64], uint32_t);
 const char *DescribeNtFiletypeFlags(char[64], uint32_t);
+const char *DescribeNtLockFileFlags(char[64], uint32_t);
 const char *DescribeNtMovFileInpFlags(char[256], uint32_t);
 const char *DescribeNtPageFlags(char[64], uint32_t);
 const char *DescribeNtPipeModeFlags(char[64], uint32_t);
@@ -72,6 +73,7 @@ const char *DescribeWhence(char[12], int);
 #define DescribeNtFileMapFlags(x)    DescribeNtFileMapFlags(alloca(64), x)
 #define DescribeNtFileShareFlags(x)  DescribeNtFileShareFlags(alloca(64), x)
 #define DescribeNtFiletypeFlags(x)   DescribeNtFiletypeFlags(alloca(64), x)
+#define DescribeNtLockFileFlags(x)   DescribeNtLockFileFlags(alloca(64), x)
 #define DescribeNtMovFileInpFlags(x) DescribeNtMovFileInpFlags(alloca(256), x)
 #define DescribeNtPageFlags(x)       DescribeNtPageFlags(alloca(64), x)
 #define DescribeNtPipeModeFlags(x)   DescribeNtPipeModeFlags(alloca(64), x)
diff --git a/libc/intrin/describemagnums.c b/libc/intrin/describemagnums.c
index 0474405fa..18e18565e 100644
--- a/libc/intrin/describemagnums.c
+++ b/libc/intrin/describemagnums.c
@@ -22,6 +22,7 @@
 
 char *DescribeMagnum(char *b, const struct MagnumStr *m, const char *p, int x) {
   char *s;
+  if (x == 127) return "CLOCK_INVALID";
   if ((s = GetMagnumStr(m, x))) {
     stpcpy(stpcpy(b, p), s);
     return b;
diff --git a/libc/intrin/describentlockfileflags.c b/libc/intrin/describentlockfileflags.c
new file mode 100644
index 000000000..d7afc98c6
--- /dev/null
+++ b/libc/intrin/describentlockfileflags.c
@@ -0,0 +1,31 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/intrin/describeflags.internal.h"
+#include "libc/macros.internal.h"
+#include "libc/nt/enum/filelockflags.h"
+
+static const struct DescribeFlags kNtLockFileFlags[] = {
+    {kNtLockfileFailImmediately, "FailImmediately"},  //
+    {kNtLockfileExclusiveLock, "ExclusiveLock"},      //
+};
+
+const char *(DescribeNtLockFileFlags)(char buf[64], uint32_t x) {
+  return DescribeFlags(buf, 64, kNtLockFileFlags, ARRAYLEN(kNtLockFileFlags),
+                       "kNtLockfile", x);
+}
diff --git a/libc/intrin/describentoverlapped.c b/libc/intrin/describentoverlapped.c
new file mode 100644
index 000000000..cc1edef4e
--- /dev/null
+++ b/libc/intrin/describentoverlapped.c
@@ -0,0 +1,49 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/intrin/describentoverlapped.internal.h"
+#include "libc/intrin/kprintf.h"
+#include "libc/macros.internal.h"
+
+const char *(DescribeNtOverlapped)(char b[128], struct NtOverlapped *o) {
+  int i = 0, n = 128;
+  bool gotsome = false;
+  if (!o) return "NULL";
+  i += ksnprintf(b + i, MAX(0, n - i), "{");
+
+  if (o->hEvent) {
+    if (gotsome) {
+      i += ksnprintf(b + i, MAX(0, n - i), ", ");
+    } else {
+      gotsome = true;
+    }
+    i += ksnprintf(b + i, MAX(0, n - i), ".hEvent = %ld", o->hEvent);
+  }
+
+  if (o->Pointer) {
+    if (gotsome) {
+      i += ksnprintf(b + i, MAX(0, n - i), ", ");
+    } else {
+      gotsome = true;
+    }
+    i += ksnprintf(b + i, MAX(0, n - i), ".Pointer = (void *)%p", o->Pointer);
+  }
+
+  i += ksnprintf(b + i, MAX(0, n - i), "}");
+  return b;
+}
diff --git a/libc/intrin/describentoverlapped.internal.h b/libc/intrin/describentoverlapped.internal.h
new file mode 100644
index 000000000..8d33a7611
--- /dev/null
+++ b/libc/intrin/describentoverlapped.internal.h
@@ -0,0 +1,13 @@
+#ifndef COSMOPOLITAN_LIBC_INTRIN_DESCRIBENTOVERLAPPED_INTERNAL_H_
+#define COSMOPOLITAN_LIBC_INTRIN_DESCRIBENTOVERLAPPED_INTERNAL_H_
+#include "libc/mem/alloca.h"
+#include "libc/nt/struct/overlapped.h"
+#if !(__ASSEMBLER__ + __LINKER__ + 0)
+COSMOPOLITAN_C_START_
+
+const char *DescribeNtOverlapped(char[128], struct NtOverlapped *);
+#define DescribeNtOverlapped(x) DescribeNtOverlapped(alloca(128), x)
+
+COSMOPOLITAN_C_END_
+#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
+#endif /* COSMOPOLITAN_LIBC_INTRIN_DESCRIBENTOVERLAPPED_INTERNAL_H_ */
diff --git a/libc/intrin/deviceiocontrol.c b/libc/intrin/deviceiocontrol.c
index e5e8c2845..6f0af1b16 100644
--- a/libc/intrin/deviceiocontrol.c
+++ b/libc/intrin/deviceiocontrol.c
@@ -16,8 +16,9 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/intrin/strace.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
+#include "libc/intrin/describentoverlapped.internal.h"
+#include "libc/intrin/strace.internal.h"
 #include "libc/nt/files.h"
 #include "libc/nt/struct/overlapped.h"
 #include "libc/nt/thunk/msabi.h"
@@ -40,8 +41,9 @@ textwindows bool32 DeviceIoControl(int64_t hDevice, uint32_t dwIoControlCode,
                              nInBufferSize, lpOutBuffer, nOutBufferSize,
                              lpBytesReturned, lpOverlapped);
   if (!ok) __winerr();
-  NTTRACE("DeviceIoControl(%ld, %#x, %p, %'zu, %p, %'zu, %p, %p) → %hhhd% m",
+  NTTRACE("DeviceIoControl(%ld, %#x, %p, %'zu, %p, %'zu, %p, %s) → %hhhd% m",
           hDevice, dwIoControlCode, lpInBuffer, nInBufferSize, lpOutBuffer,
-          nOutBufferSize, lpBytesReturned, lpOverlapped, ok);
+          nOutBufferSize, lpBytesReturned, DescribeNtOverlapped(lpOverlapped),
+          ok);
   return ok;
 }
diff --git a/libc/intrin/kclocknames.S b/libc/intrin/kclocknames.S
index cd3c0f120..02c6e9f14 100644
--- a/libc/intrin/kclocknames.S
+++ b/libc/intrin/kclocknames.S
@@ -33,17 +33,24 @@
 kClockNames:
 	.e	CLOCK_REALTIME,"REALTIME"
 	.e	CLOCK_REALTIME_FAST,"REALTIME_FAST"
+	.e	CLOCK_REALTIME_PRECISE,"REALTIME_PRECISE"
 	.e	CLOCK_MONOTONIC,"MONOTONIC"
 	.e	CLOCK_MONOTONIC_FAST,"MONOTONIC_FAST"
 	.e	CLOCK_MONOTONIC_RAW,"MONOTONIC_RAW"
+	.e	CLOCK_MONOTONIC_PRECISE,"MONOTONIC_PRECISE"
 	.e	CLOCK_REALTIME_COARSE,"REALTIME_COARSE"
 	.e	CLOCK_MONOTONIC_COARSE,"MONOTONIC_COARSE"
 	.e	CLOCK_PROCESS_CPUTIME_ID,"PROCESS_CPUTIME_ID"
+	.e	CLOCK_THREAD_CPUTIME_ID,"THREAD_CPUTIME_ID"
 	.e	CLOCK_TAI,"TAI"
 	.e	CLOCK_PROF,"PROF"
 	.e	CLOCK_BOOTTIME,"BOOTTIME"
 	.e	CLOCK_REALTIME_ALARM,"REALTIME_ALARM"
 	.e	CLOCK_BOOTTIME_ALARM,"BOOTTIME_ALARM"
+	.e	CLOCK_UPTIME,"UPTIME"
+	.e	CLOCK_UPTIME_FAST,"UPTIME_FAST"
+	.e	CLOCK_UPTIME_PRECISE,"UPTIME_PRECISE"
+	.e	CLOCK_SECOND,"SECOND"
 	.long	MAGNUM_TERMINATOR
 	.endobj	kClockNames,globl,hidden
 	.overrun
diff --git a/libc/intrin/kprintf.greg.c b/libc/intrin/kprintf.greg.c
index ffee3ed4f..3b91f4260 100644
--- a/libc/intrin/kprintf.greg.c
+++ b/libc/intrin/kprintf.greg.c
@@ -48,6 +48,7 @@
 #include "libc/runtime/runtime.h"
 #include "libc/runtime/symbols.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/str/utf16.h"
 #include "libc/sysv/consts/nr.h"
 #include "libc/sysv/consts/prot.h"
diff --git a/libc/intrin/lockfileex.c b/libc/intrin/lockfileex.c
new file mode 100644
index 000000000..2a8d1b671
--- /dev/null
+++ b/libc/intrin/lockfileex.c
@@ -0,0 +1,50 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/syscall_support-nt.internal.h"
+#include "libc/intrin/describeflags.internal.h"
+#include "libc/intrin/describentoverlapped.internal.h"
+#include "libc/intrin/strace.internal.h"
+#include "libc/nt/files.h"
+
+__msabi extern typeof(LockFileEx) *const __imp_LockFileEx;
+
+/**
+ * Locks file on the New Technology.
+ *
+ * @return handle, or -1 on failure
+ * @note this wrapper takes care of ABI, STRACE(), and __winerr()
+ */
+bool32 LockFileEx(int64_t hFile, uint32_t dwFlags, uint32_t dwReserved,
+                  uint32_t nNumberOfBytesToLockLow,
+                  uint32_t nNumberOfBytesToLockHigh,
+                  struct NtOverlapped *lpOverlapped) {
+  bool32 ok;
+  STRACE("LockFileEx(%ld, %s, %#x, %'zu, %s) → ...", hFile,
+         DescribeNtLockFileFlags(dwFlags), dwReserved,
+         (uint64_t)nNumberOfBytesToLockHigh << 32 | nNumberOfBytesToLockLow,
+         DescribeNtOverlapped(lpOverlapped));
+  ok = __imp_LockFileEx(hFile, dwFlags, dwReserved, nNumberOfBytesToLockLow,
+                        nNumberOfBytesToLockHigh, lpOverlapped);
+  if (!ok) __winerr();
+  STRACE("LockFileEx(%ld, %s, %#x, %'zu, [%s]) → %hhhd% m", hFile,
+         DescribeNtLockFileFlags(dwFlags), dwReserved,
+         (uint64_t)nNumberOfBytesToLockHigh << 32 | nNumberOfBytesToLockLow,
+         DescribeNtOverlapped(lpOverlapped), ok);
+  return ok;
+}
diff --git a/libc/intrin/unlockfileex.c b/libc/intrin/unlockfileex.c
new file mode 100644
index 000000000..4e5debda2
--- /dev/null
+++ b/libc/intrin/unlockfileex.c
@@ -0,0 +1,50 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/syscall_support-nt.internal.h"
+#include "libc/errno.h"
+#include "libc/intrin/describeflags.internal.h"
+#include "libc/intrin/describentoverlapped.internal.h"
+#include "libc/intrin/strace.internal.h"
+#include "libc/nt/files.h"
+#include "libc/str/str.h"
+
+__msabi extern typeof(UnlockFileEx) *const __imp_UnlockFileEx;
+
+/**
+ * Unlocks file on the New Technology.
+ *
+ * @return handle, or -1 on failure
+ * @note this wrapper takes care of ABI, STRACE(), and __winerr()
+ */
+bool32 UnlockFileEx(int64_t hFile, uint32_t dwReserved,
+                    uint32_t nNumberOfBytesToUnlockLow,
+                    uint32_t nNumberOfBytesToUnlockHigh,
+                    struct NtOverlapped *lpOverlapped) {
+  bool32 ok;
+  STRACE("UnlockFileEx(%ld, %#x, %'zu, %s) → ...", hFile, dwReserved,
+         (uint64_t)nNumberOfBytesToUnlockHigh << 32 | nNumberOfBytesToUnlockLow,
+         DescribeNtOverlapped(lpOverlapped));
+  ok = __imp_UnlockFileEx(hFile, dwReserved, nNumberOfBytesToUnlockLow,
+                          nNumberOfBytesToUnlockHigh, lpOverlapped);
+  if (!ok) __winerr();
+  STRACE("UnlockFileEx(%ld, %#x, %'zu, [%s]) → %hhhd% m", hFile, dwReserved,
+         (uint64_t)nNumberOfBytesToUnlockHigh << 32 | nNumberOfBytesToUnlockLow,
+         DescribeNtOverlapped(lpOverlapped), ok);
+  return ok;
+}
diff --git a/libc/intrin/wsarecv.c b/libc/intrin/wsarecv.c
index 8029cccfd..d4e40f72d 100644
--- a/libc/intrin/wsarecv.c
+++ b/libc/intrin/wsarecv.c
@@ -16,10 +16,11 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/intrin/strace.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/intrin/describeflags.internal.h"
+#include "libc/intrin/describentoverlapped.internal.h"
 #include "libc/intrin/kprintf.h"
+#include "libc/intrin/strace.internal.h"
 #include "libc/nt/thunk/msabi.h"
 #include "libc/nt/winsock.h"
 
@@ -55,8 +56,9 @@ textwindows int WSARecv(
     kprintf(STRACE_PROLOGUE "WSARecv(%lu, [", s);
     DescribeIovNt(inout_lpBuffers, dwBufferCount,
                   rc != -1 ? NumberOfBytesRecvd : 0);
-    kprintf("], %u, [%'u], %p, %p, %p) → %d% lm\n", dwBufferCount,
-            NumberOfBytesRecvd, inout_lpFlags, opt_inout_lpOverlapped,
+    kprintf("], %u, [%'u], %p, %s, %p) → %d% lm\n", dwBufferCount,
+            NumberOfBytesRecvd, inout_lpFlags,
+            DescribeNtOverlapped(opt_inout_lpOverlapped),
             opt_lpCompletionRoutine, rc);
   }
 #else
diff --git a/libc/intrin/wsarecvfrom.c b/libc/intrin/wsarecvfrom.c
index 6d49a094c..ef13557d2 100644
--- a/libc/intrin/wsarecvfrom.c
+++ b/libc/intrin/wsarecvfrom.c
@@ -16,10 +16,11 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/intrin/strace.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/intrin/describeflags.internal.h"
+#include "libc/intrin/describentoverlapped.internal.h"
 #include "libc/intrin/kprintf.h"
+#include "libc/intrin/strace.internal.h"
 #include "libc/nt/thunk/msabi.h"
 #include "libc/nt/winsock.h"
 
@@ -57,9 +58,10 @@ textwindows int WSARecvFrom(
     kprintf(STRACE_PROLOGUE "WSARecvFrom(%lu, [", s);
     DescribeIovNt(inout_lpBuffers, dwBufferCount,
                   rc != -1 ? NumberOfBytesRecvd : 0);
-    kprintf("], %u, [%'u], %p, %p, %p, %p, %p) → %d% lm\n", dwBufferCount,
+    kprintf("], %u, [%'u], %p, %p, %p, %s, %p) → %d% lm\n", dwBufferCount,
             NumberOfBytesRecvd, opt_out_fromsockaddr, opt_inout_fromsockaddrlen,
-            inout_lpFlags, opt_inout_lpOverlapped, opt_lpCompletionRoutine, rc);
+            inout_lpFlags, DescribeNtOverlapped(opt_inout_lpOverlapped),
+            opt_lpCompletionRoutine, rc);
   }
 #else
   rc = __imp_WSARecvFrom(s, inout_lpBuffers, dwBufferCount,
diff --git a/libc/nt/errors.h b/libc/nt/errors.h
index 484e668e6..51018e957 100644
--- a/libc/nt/errors.h
+++ b/libc/nt/errors.h
@@ -131,7 +131,7 @@
 #define kNtErrorTooManyTcbs 155
 #define kNtErrorSignalRefused 156
 #define kNtErrorDiscarded 157
-#define kNtErrorNotLocked 158
+#define kNtErrorNotLocked 158 /* ENOLCK */
 #define kNtErrorBadThreadidAddr 159
 #define kNtErrorBadArguments 160
 #define kNtErrorBadPathname 161
@@ -1531,7 +1531,7 @@
 #define kNtErrorLogSectorParityInvalid 6601
 #define kNtErrorLogSectorRemapped 6602
 #define kNtErrorLogBlockIncomplete 6603
-#define kNtErrorLogInvalidRange 6604
+#define kNtErrorLogInvalidRange 6604 /* ERANGE */
 #define kNtErrorLogBlocksExhausted 6605
 #define kNtErrorLogReadContextInvalid 6606
 #define kNtErrorLogRestartInvalid 6607
diff --git a/libc/nt/files.h b/libc/nt/files.h
index b61db4569..df6da98bb 100644
--- a/libc/nt/files.h
+++ b/libc/nt/files.h
@@ -116,13 +116,13 @@ bool32 DeviceIoControl(int64_t hDevice, uint32_t dwIoControlCode,
 bool32 LockFile(int64_t hFile, uint32_t dwFileOffsetLow,
                 uint32_t dwFileOffsetHigh, uint32_t nNumberOfBytesToLockLow,
                 uint32_t nNumberOfBytesToLockHigh);
+bool32 UnlockFile(int64_t hFile, uint32_t dwFileOffsetLow,
+                  uint32_t dwFileOffsetHigh, uint32_t nNumberOfBytesToUnlockLow,
+                  uint32_t nNumberOfBytesToUnlockHigh);
 bool32 LockFileEx(int64_t hFile, uint32_t dwFlags, uint32_t dwReserved,
                   uint32_t nNumberOfBytesToLockLow,
                   uint32_t nNumberOfBytesToLockHigh,
                   struct NtOverlapped *lpOverlapped) paramsnonnull();
-bool32 UnlockFile(int64_t hFile, uint32_t dwFileOffsetLow,
-                  uint32_t dwFileOffsetHigh, uint32_t nNumberOfBytesToUnlockLow,
-                  uint32_t nNumberOfBytesToUnlockHigh);
 bool32 UnlockFileEx(int64_t hFile, uint32_t dwReserved,
                     uint32_t nNumberOfBytesToUnlockLow,
                     uint32_t nNumberOfBytesToUnlockHigh,
diff --git a/libc/nt/kernel32/LockFileEx.s b/libc/nt/kernel32/LockFileEx.s
index 9aba0a595..f74843927 100644
--- a/libc/nt/kernel32/LockFileEx.s
+++ b/libc/nt/kernel32/LockFileEx.s
@@ -2,11 +2,11 @@
 .imp	kernel32,__imp_LockFileEx,LockFileEx,0
 
 	.text.windows
-LockFileEx:
+__LockFileEx:
 	push	%rbp
 	mov	%rsp,%rbp
 	.profilable
 	mov	__imp_LockFileEx(%rip),%rax
 	jmp	__sysv2nt6
-	.endfn	LockFileEx,globl
+	.endfn	__LockFileEx,globl
 	.previous
diff --git a/libc/nt/kernel32/UnlockFileEx.s b/libc/nt/kernel32/UnlockFileEx.s
index 577232d60..0dedd8b8b 100644
--- a/libc/nt/kernel32/UnlockFileEx.s
+++ b/libc/nt/kernel32/UnlockFileEx.s
@@ -2,11 +2,11 @@
 .imp	kernel32,__imp_UnlockFileEx,UnlockFileEx,0
 
 	.text.windows
-UnlockFileEx:
+__UnlockFileEx:
 	push	%rbp
 	mov	%rsp,%rbp
 	.profilable
 	mov	__imp_UnlockFileEx(%rip),%rax
 	jmp	__sysv2nt6
-	.endfn	UnlockFileEx,globl
+	.endfn	__UnlockFileEx,globl
 	.previous
diff --git a/libc/nt/master.sh b/libc/nt/master.sh
index 1d269f4fc..415068d57 100755
--- a/libc/nt/master.sh
+++ b/libc/nt/master.sh
@@ -700,7 +700,6 @@ imp	'LocalUnlock'						LocalUnlock						kernel32	0
 imp	'LocaleNameToLCID'					LocaleNameToLCID					kernel32	0
 imp	'LocateXStateFeature'					LocateXStateFeature					kernel32	0
 imp	'LockFile'						LockFile						kernel32	0	5
-imp	'LockFileEx'						LockFileEx						kernel32	0	6
 imp	'LockResource'						LockResource						kernel32	0	1
 imp	'MapUserPhysicalPages'					MapUserPhysicalPages					kernel32	0
 imp	'MapUserPhysicalPagesScatter'				MapUserPhysicalPagesScatter				kernel32	986
@@ -1024,7 +1023,6 @@ imp	'UTUnRegister'						UTUnRegister						kernel32	1459
 imp	'UmsThreadYield'					UmsThreadYield						kernel32	1460
 imp	'UnhandledExceptionFilter'				UnhandledExceptionFilter				kernel32	0
 imp	'UnlockFile'						UnlockFile						kernel32	0	5
-imp	'UnlockFileEx'						UnlockFileEx						kernel32	0	5
 imp	'UnmapViewOfFile2'					UnmapViewOfFile2					kernel32	0	2
 imp	'UnmapViewOfFileEx'					UnmapViewOfFileEx					kernel32	0	3
 imp	'UnregisterApplicationRecoveryCallback'			UnregisterApplicationRecoveryCallback			kernel32	1466
@@ -1120,6 +1118,7 @@ imp	'__FlushViewOfFile'					FlushViewOfFile						kernel32	0	2
 imp	'__GenerateConsoleCtrlEvent'				GenerateConsoleCtrlEvent				kernel32	0	2
 imp	'__GetExitCodeProcess'					GetExitCodeProcess					kernel32	0	2
 imp	'__GetFileAttributes'					GetFileAttributesW					kernel32	0	1
+imp	'__LockFileEx'						LockFileEx						kernel32	0	6
 imp	'__MapViewOfFileEx'					MapViewOfFileEx						kernel32	0	6
 imp	'__MapViewOfFileExNuma'					MapViewOfFileExNuma					kernel32	0	7
 imp	'__MoveFileEx'						MoveFileExW						kernel32	0	3
@@ -1128,6 +1127,7 @@ imp	'__ReOpenFile'						ReOpenFile						kernel32	0	4	# TODO(jart): 6.2 and highe
 imp	'__RemoveDirectory'					RemoveDirectoryW					kernel32	0	1
 imp	'__SetCurrentDirectory'					SetCurrentDirectoryW					kernel32	0	1
 imp	'__TerminateProcess'					TerminateProcess					kernel32	0	2
+imp	'__UnlockFileEx'					UnlockFileEx						kernel32	0	5
 imp	'__UnmapViewOfFile'					UnmapViewOfFile						kernel32	0	1
 imp	'__VirtualProtect'					VirtualProtect						kernel32	0	4
 imp	'__WaitForMultipleObjects'				WaitForMultipleObjects					kernel32	0	4
diff --git a/libc/stdio/fdopen.c b/libc/stdio/fdopen.c
index de8875d62..ad295a27d 100644
--- a/libc/stdio/fdopen.c
+++ b/libc/stdio/fdopen.c
@@ -38,7 +38,7 @@ FILE *fdopen(int fd, const char *mode) {
     f->fd = fd;
     f->bufmode = ischardev(fd) ? _IOLBF : _IOFBF;
     f->iomode = fopenflags(mode);
-    f->lock._type = PTHREAD_MUTEX_RECURSIVE;
+    ((pthread_mutex_t *)f->lock)->_type = PTHREAD_MUTEX_RECURSIVE;
     f->size = BUFSIZ;
     if ((f->buf = malloc(f->size))) {
       if ((f->iomode & O_ACCMODE) != O_RDONLY) {
diff --git a/libc/stdio/flockfile.c b/libc/stdio/flockfile.c
index 36ae8a3e5..852459e73 100644
--- a/libc/stdio/flockfile.c
+++ b/libc/stdio/flockfile.c
@@ -23,5 +23,5 @@
  * Acquires reentrant lock on stdio object, blocking if needed.
  */
 void(flockfile)(FILE *f) {
-  pthread_mutex_lock(&f->lock);
+  pthread_mutex_lock((pthread_mutex_t *)f->lock);
 }
diff --git a/libc/stdio/fmemopen.c b/libc/stdio/fmemopen.c
index 3183982a3..1425ae79a 100644
--- a/libc/stdio/fmemopen.c
+++ b/libc/stdio/fmemopen.c
@@ -54,7 +54,7 @@ FILE *fmemopen(void *buf, size_t size, const char *mode) {
   f->end = size;
   f->size = size;
   f->iomode = fopenflags(mode);
-  f->lock._type = PTHREAD_MUTEX_RECURSIVE;
+  ((pthread_mutex_t *)f->lock)->_type = PTHREAD_MUTEX_RECURSIVE;
   if (f->iomode & O_APPEND) {
     if ((p = memchr(buf, '\0', size))) {
       f->beg = p - (char *)buf;
diff --git a/libc/stdio/ftrylockfile.c b/libc/stdio/ftrylockfile.c
index 501c9b3a0..e29a2c28c 100644
--- a/libc/stdio/ftrylockfile.c
+++ b/libc/stdio/ftrylockfile.c
@@ -16,6 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/stdio/lock.internal.h"
 #include "libc/stdio/stdio.h"
 
 /**
@@ -24,5 +25,5 @@
  * @return 0 on success, or non-zero if another thread owns the lock
  */
 int(ftrylockfile)(FILE *f) {
-  return pthread_mutex_trylock(&f->lock);
+  return pthread_mutex_trylock((pthread_mutex_t *)f->lock);
 }
diff --git a/libc/stdio/funlockfile.c b/libc/stdio/funlockfile.c
index bef058320..20a9358f6 100644
--- a/libc/stdio/funlockfile.c
+++ b/libc/stdio/funlockfile.c
@@ -16,11 +16,12 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/stdio/lock.internal.h"
 #include "libc/stdio/stdio.h"
 
 /**
  * Releases lock on stdio object.
  */
 void(funlockfile)(FILE *f) {
-  pthread_mutex_unlock(&f->lock);
+  pthread_mutex_unlock((pthread_mutex_t *)f->lock);
 }
diff --git a/libc/stdio/gets.c b/libc/stdio/gets.c
index d62e6239f..a499b8721 100644
--- a/libc/stdio/gets.c
+++ b/libc/stdio/gets.c
@@ -19,6 +19,6 @@
 #include "libc/limits.h"
 #include "libc/stdio/stdio.h"
 
-compatfn char *gets(char *s) {
+char *gets(char *s) {
   return fgets(s, INT_MAX, stdin);
 }
diff --git a/libc/stdio/stdio.h b/libc/stdio/stdio.h
index 401e344e2..8a5e4e1ae 100644
--- a/libc/stdio/stdio.h
+++ b/libc/stdio/stdio.h
@@ -1,9 +1,7 @@
-#ifndef COSMOPOLITAN_LIBC_STDIO_STDIO_H_
-#define COSMOPOLITAN_LIBC_STDIO_STDIO_H_
-#include "libc/fmt/pflink.h"
-#include "libc/thread/thread.h"
-
+#ifndef _STDIO_H
 #define _STDIO_H
+#include "libc/fmt/pflink.h"
+
 #define L_ctermid    20
 #define FILENAME_MAX PATH_MAX
 #define FOPEN_MAX    1000
@@ -17,19 +15,19 @@ COSMOPOLITAN_C_START_
 ╚────────────────────────────────────────────────────────────────────────────│*/
 
 typedef struct FILE {
-  uint8_t bufmode;      /* 0x00 _IOFBF, etc. (ignored if fd=-1) */
-  bool noclose;         /* 0x01 for fake dup() todo delete! */
-  uint32_t iomode;      /* 0x04 O_RDONLY, etc. (ignored if fd=-1) */
-  int32_t state;        /* 0x08 0=OK, -1=EOF, >0=errno */
-  int fd;               /* 0x0c ≥0=fd, -1=closed|buffer */
-  uint32_t beg;         /* 0x10 */
-  uint32_t end;         /* 0x14 */
-  char *buf;            /* 0x18 */
-  uint32_t size;        /* 0x20 */
-  uint32_t nofree;      /* 0x24 */
-  int pid;              /* 0x28 */
-  char *getln;          /* 0x30 */
-  pthread_mutex_t lock; /* 0x38 */
+  uint8_t bufmode; /* 0x00 _IOFBF, etc. (ignored if fd=-1) */
+  bool noclose;    /* 0x01 for fake dup() todo delete! */
+  uint32_t iomode; /* 0x04 O_RDONLY, etc. (ignored if fd=-1) */
+  int32_t state;   /* 0x08 0=OK, -1=EOF, >0=errno */
+  int fd;          /* 0x0c ≥0=fd, -1=closed|buffer */
+  uint32_t beg;    /* 0x10 */
+  uint32_t end;    /* 0x14 */
+  char *buf;       /* 0x18 */
+  uint32_t size;   /* 0x20 */
+  uint32_t nofree; /* 0x24 */
+  int pid;         /* 0x28 */
+  char *getln;     /* 0x30 */
+  char lock[16];   /* 0x38 */
 } FILE;
 
 extern FILE *stdin;
@@ -91,9 +89,9 @@ char *ctermid(char *);
 void perror(const char *) relegated;
 
 typedef uint64_t fpos_t;
-compatfn char *gets(char *) paramsnonnull();
-compatfn int fgetpos(FILE *, fpos_t *) paramsnonnull();
-compatfn int fsetpos(FILE *, const fpos_t *) paramsnonnull();
+char *gets(char *) paramsnonnull();
+int fgetpos(FILE *, fpos_t *) paramsnonnull();
+int fsetpos(FILE *, const fpos_t *) paramsnonnull();
 
 int system(const char *);
 int systemexec(const char *);
@@ -195,4 +193,4 @@ int vfprintf_unlocked(FILE *, const char *, va_list)
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
-#endif /* COSMOPOLITAN_LIBC_STDIO_STDIO_H_ */
+#endif /* _STDIO_H */
diff --git a/libc/str/_tpenc.h b/libc/str/_tpenc.h
deleted file mode 100755
index e69de29bb..000000000
diff --git a/libc/str/djbsort.c b/libc/str/djbsort.c
index 2ad8d5055..17b0e303e 100644
--- a/libc/str/djbsort.c
+++ b/libc/str/djbsort.c
@@ -18,40 +18,11 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/dce.h"
 #include "libc/intrin/asan.internal.h"
-#include "libc/intrin/bsr.h"
-#include "libc/mem/alg.h"
-#include "libc/nexgen32e/nexgen32e.h"
 #include "libc/nexgen32e/x86feature.h"
+#include "libc/runtime/runtime.h"
 
 void djbsort_avx2(int32_t *, long);
 
-static dontinline void intsort(int *x, size_t n, size_t t) {
-  int a, b, c;
-  size_t i, p, q;
-  for (p = t; p > 0; p >>= 1) {
-    for (i = 0; i < n - p; ++i) {
-      if (!(i & p)) {
-        a = x[i + 0];
-        b = x[i + p];
-        if (a > b) c = a, a = b, b = c;
-        x[i + 0] = a;
-        x[i + p] = b;
-      }
-    }
-    for (q = t; q > p; q >>= 1) {
-      for (i = 0; i < n - q; ++i) {
-        if (!(i & p)) {
-          a = x[i + p];
-          b = x[i + q];
-          if (a > b) c = a, a = b, b = c;
-          x[i + p] = a;
-          x[i + q] = b;
-        }
-      }
-    }
-  }
-}
-
 /**
  * D.J. Bernstein's outrageously fast integer sorting algorithm.
  */
@@ -65,7 +36,7 @@ void djbsort(int32_t *a, size_t n) {
     if (X86_HAVE(AVX2)) {
       djbsort_avx2(a, n);
     } else {
-      intsort(a, n, 1ul << _bsrl(n - 1));
+      _intsort(a, n);
     }
   }
 }
diff --git a/libc/str/memcasecmp.c b/libc/str/memcasecmp.c
index a4a58f19d..03569ed90 100644
--- a/libc/str/memcasecmp.c
+++ b/libc/str/memcasecmp.c
@@ -18,6 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/intrin/bits.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Compares memory case-insensitively.
diff --git a/libc/str/startswithi.c b/libc/str/startswithi.c
index a749d733d..cc3f81476 100644
--- a/libc/str/startswithi.c
+++ b/libc/str/startswithi.c
@@ -17,6 +17,7 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 bool _startswithi(const char *s, const char *prefix) {
   for (;;) {
diff --git a/libc/str/str.h b/libc/str/str.h
index a39fd83ac..ea805da38 100644
--- a/libc/str/str.h
+++ b/libc/str/str.h
@@ -6,13 +6,6 @@
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
-extern const int8_t kHexToInt[256];
-extern const uint8_t gperf_downcase[256];
-extern const uint8_t kToLower[256];
-extern const uint8_t kToUpper[256];
-extern const uint8_t kBase36[256];
-extern const char16_t kCp437[256];
-
 int isascii(int);
 int isspace(int);
 int isalpha(int);
diff --git a/libc/str/strcasecmp.c b/libc/str/strcasecmp.c
index 9dfcf80f4..cc05da1ec 100644
--- a/libc/str/strcasecmp.c
+++ b/libc/str/strcasecmp.c
@@ -19,6 +19,7 @@
 #include "libc/dce.h"
 #include "libc/intrin/asan.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Compares NUL-terminated strings ascii case-insensitively.
diff --git a/libc/str/strcasestr.c b/libc/str/strcasestr.c
index fee268a3d..1d7d31877 100644
--- a/libc/str/strcasestr.c
+++ b/libc/str/strcasestr.c
@@ -19,6 +19,7 @@
 #include "libc/dce.h"
 #include "libc/intrin/asan.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 typedef char xmm_t __attribute__((__vector_size__(16), __aligned__(16)));
 
diff --git a/libc/str/strncasecmp.c b/libc/str/strncasecmp.c
index bf6ae681a..f63658d01 100644
--- a/libc/str/strncasecmp.c
+++ b/libc/str/strncasecmp.c
@@ -17,6 +17,7 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * Compares NUL-terminated strings case-insensitively w/ limit.
diff --git a/libc/str/tab.internal.h b/libc/str/tab.internal.h
new file mode 100644
index 000000000..e6e15d33a
--- /dev/null
+++ b/libc/str/tab.internal.h
@@ -0,0 +1,15 @@
+#ifndef COSMOPOLITAN_LIBC_STR_TAB_INTERNAL_H_
+#define COSMOPOLITAN_LIBC_STR_TAB_INTERNAL_H_
+#if !(__ASSEMBLER__ + __LINKER__ + 0)
+COSMOPOLITAN_C_START_
+
+extern const int8_t kHexToInt[256];
+extern const uint8_t gperf_downcase[256];
+extern const uint8_t kToLower[256];
+extern const uint8_t kToUpper[256];
+extern const uint8_t kBase36[256];
+extern const char16_t kCp437[256];
+
+COSMOPOLITAN_C_END_
+#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
+#endif /* COSMOPOLITAN_LIBC_STR_TAB_INTERNAL_H_ */
diff --git a/libc/sysv/consts.sh b/libc/sysv/consts.sh
index f0fa3aa50..93cba7b4a 100755
--- a/libc/sysv/consts.sh
+++ b/libc/sysv/consts.sh
@@ -57,11 +57,11 @@ syscon	errno	ESPIPE					29			29			29			29			29			25			# invalid seek; unix conse
 syscon	errno	EROFS					30			30			30			30			30			6009			# read-only filesystem; unix consensus; kNtErrorFileReadOnly; raised by access(2), acct(2), bind(2), chmod(2), chown(2), link(2), mkdir(2), mknod(2), mount(2), open(2), rename(2), rmdir(2), symlink(2), truncate(2), unlink(2), utime(2), utimensat(2)
 syscon	errno	EMLINK					31			31			31			31			31			1142			# too many links; unix consensus; kNtErrorTooManyLinks; raised by link(2), mkdir(2), rename(2)
 syscon	errno	EPIPE					32			32			32			32			32			109			# broken pipe; unix consensus; kNtErrorBrokenPipe; raised by send(2), write(2), tcp(7), unix(7), ip(7)
-syscon	errno	EDOM					33			33			33			33			33			33			# mathematics argument out of domain of function; bsd consensus; fudged on NT; returned by cos(3), fmod(3), log1p(3), sin(3), tan(3), tgamma(3)
-syscon	errno	ERANGE					34			34			34			34			34			34			# result too large; bsd consensus; fudged on NT; raised by getxattr(2), listxattr(2), lookup_dcookie(2), prctl(2), quotactl(2), semctl(2), semop(2), setxattr(2)
+syscon	errno	EDOM					33			33			33			33			33			20000			# mathematics argument out of domain of function; bsd consensus; made up on NT; returned by cos(3), fmod(3), log1p(3), sin(3), tan(3), tgamma(3)
+syscon	errno	ERANGE					34			34			34			34			34			6604			# result too large; bsd consensus; kNtErrorLogInvalidRange; raised by getxattr(2), listxattr(2), lookup_dcookie(2), prctl(2), quotactl(2), semctl(2), semop(2), setxattr(2)
 syscon	errno	EDEADLK					35			11			11			11			11			1131			# resource deadlock avoided; bsd consensus; kNtErrorPossibleDeadlock; raised by fcntl(2), keyctl(2)
 syscon	errno	ENAMETOOLONG				36			63			63			63			63			10063			# filename too long; bsd consensus; WSAENAMETOOLONG; raised by access(2), acct(2), bind(2), chdir(2), chmod(2), chown(2), chroot(2), execve(2), gethostname(2), inotify_add_watch(2), link(2), lookup_dcookie(2), mkdir(2), mknod(2), mount(2), open(2), readlink(2), rename(2), rmdir(2), spu_create(2), stat(2), statfs(2), statx(2), symlink(2), truncate(2), umount(2), unlink(2), utimensat(2)
-syscon	errno	ENOLCK					37			77			77			77			77			0			# no locks available; bsd consensus; raised by fcntl(2), flock(2)
+syscon	errno	ENOLCK					37			77			77			77			77			158			# no locks available; kNtErrorNotLocked; bsd consensus; raised by fcntl(2), flock(2)
 syscon	errno	ENOTEMPTY				39			66			66			66			66			145			# directory not empty; bsd consensus; kNtErrorDirNotEmpty (TODO: What is WSAENOTEMPTY? 10066); raised by rmdir(2)
 syscon	errno	ELOOP					40			62			62			62			62			1921			# too many levels of symbolic links; bsd consensus; kNtErrorCantResolveFilename; raised by access(2), acct(2), bind(2), chdir(2), chmod(2), chown(2), chroot(2), epoll_ctl(2), execve(2), execveat(2), keyctl(2), link(2), mkdir(2), mknod(2), mount(2), open(2), open_by_handle_at(2), openat2(2), readlink(2), rename(2), rmdir(2), spu_create(2), stat(2), statfs(2), statx(2), symlink(2), truncate(2), unlink(2), utimensat(2)
 syscon	errno	ENOMSG					42			91			83			90			83			0			# raised by msgop(2)
@@ -328,10 +328,10 @@ syscon	access	R_OK					4			4			4			4			4			0x80000000		# unix consensus and kNtG
 #	flock() flags
 #
 #	group	name					GNU/Systemd		XNU's Not UNIX!		FreeBSD			OpenBSD			NetBSD			The New Technology	Commentary
-syscon	lock	LOCK_SH					1			1			1			1			1			0			# shared [unix consensus]
+syscon	lock	LOCK_SH					1			1			1			1			1			0			# shared [unix consensus]; hard-coded into flock-nt.c too
 syscon	lock	LOCK_EX					2			2			2			2			2			2			# exclusive [consensus!] a.k.a. kNtLockfileExclusiveLock
 syscon	lock	LOCK_NB					4			4			4			4			4			1			# non-blocking [unix consensus] a.k.a. kNtLockfileFailImmediately
-syscon	lock	LOCK_UN					8			8			8			8			8			8			# unlock [unix consensus & faked NT]
+syscon	lock	LOCK_UN					8			8			8			8			8			8			# unlock [unix consensus & faked NT]; hard-coded into flock-nt.c too
 
 #	waitpid() / wait4() options
 #
diff --git a/libc/sysv/consts/EAGAIN.s b/libc/sysv/consts/EAGAIN.s
index 289348a8f..bec611ad4 100644
--- a/libc/sysv/consts/EAGAIN.s
+++ b/libc/sysv/consts/EAGAIN.s
@@ -1,2 +1,3 @@
 .include "o/libc/sysv/consts/syscon.internal.inc"
 .syscon errno,EAGAIN,11,35,35,35,35,10035
+.yoink kDos2Errno.EAGAIN
diff --git a/libc/sysv/consts/EDOM.s b/libc/sysv/consts/EDOM.s
index 285a5bd8b..4f9bee5d7 100644
--- a/libc/sysv/consts/EDOM.s
+++ b/libc/sysv/consts/EDOM.s
@@ -1,2 +1,2 @@
 .include "o/libc/sysv/consts/syscon.internal.inc"
-.syscon errno,EDOM,33,33,33,33,33,33
+.syscon errno,EDOM,33,33,33,33,33,20000
diff --git a/libc/sysv/consts/ENOLCK.s b/libc/sysv/consts/ENOLCK.s
index a260aab23..9686bd637 100644
--- a/libc/sysv/consts/ENOLCK.s
+++ b/libc/sysv/consts/ENOLCK.s
@@ -1,2 +1,2 @@
 .include "o/libc/sysv/consts/syscon.internal.inc"
-.syscon errno,ENOLCK,37,77,77,77,77,0
+.syscon errno,ENOLCK,37,77,77,77,77,158
diff --git a/libc/sysv/consts/ERANGE.s b/libc/sysv/consts/ERANGE.s
index 64182ad33..121962c60 100644
--- a/libc/sysv/consts/ERANGE.s
+++ b/libc/sysv/consts/ERANGE.s
@@ -1,2 +1,2 @@
 .include "o/libc/sysv/consts/syscon.internal.inc"
-.syscon errno,ERANGE,34,34,34,34,34,34
+.syscon errno,ERANGE,34,34,34,34,34,6604
diff --git a/libc/sysv/dos2errno.sh b/libc/sysv/dos2errno.sh
index a9ca19cbb..2dea062fc 100755
--- a/libc/sysv/dos2errno.sh
+++ b/libc/sysv/dos2errno.sh
@@ -129,7 +129,7 @@ dos	kNtErrorInvalidFunction         EINVAL
 dos	kNtErrorInvalidNetname          EADDRNOTAVAIL
 dos	kNtErrorInvalidUserBuffer	EMSGSIZE
 dos	kNtErrorIoPending               EINPROGRESS
-dos	kNtErrorLockViolation           EACCES
+dos	kNtErrorLockViolation           EAGAIN
 dos	kNtErrorMoreData                EMSGSIZE
 dos	kNtErrorNetnameDeleted          ECONNABORTED
 dos	kNtErrorNetworkAccessDenied	EACCES
@@ -139,7 +139,6 @@ dos	kNtErrorNonpagedSystemResources	ENOMEM
 dos	kNtErrorNotEnoughMemory         ENOMEM
 dos	kNtErrorNotEnoughQuota          ENOMEM
 dos	kNtErrorNotFound                ENOENT
-dos	kNtErrorNotLocked               EACCES
 dos	kNtErrorNotReady                EACCES
 dos	kNtErrorNotSupported            ENOTSUP
 dos	kNtErrorNoMoreFiles             ENOENT
diff --git a/libc/sysv/dos2errno/EACCES.S b/libc/sysv/dos2errno/EACCES.S
index 71d4e1264..4af9d1a26 100644
--- a/libc/sysv/dos2errno/EACCES.S
+++ b/libc/sysv/dos2errno/EACCES.S
@@ -13,9 +13,7 @@ kDos2Errno.EACCES:
 	.e	kNtErrorCannotMake,EACCES
 	.e	kNtErrorCrc,EACCES
 	.e	kNtErrorGenFailure,EACCES
-	.e	kNtErrorLockViolation,EACCES
 	.e	kNtErrorNetworkAccessDenied,EACCES
-	.e	kNtErrorNotLocked,EACCES
 	.e	kNtErrorNotReady,EACCES
 	.e	kNtErrorOutOfPaper,EACCES
 	.e	kNtErrorSectorNotFound,EACCES
diff --git a/libc/sysv/dos2errno/EAGAIN.S b/libc/sysv/dos2errno/EAGAIN.S
new file mode 100644
index 000000000..6fa2738b8
--- /dev/null
+++ b/libc/sysv/dos2errno/EAGAIN.S
@@ -0,0 +1,11 @@
+//	generated by libc/sysv/dos2errno.sh
+#include "libc/nt/errors.h"
+	.macro	.e doscode systemv
+	.short	\doscode
+	.long	\systemv
+	.endm
+	.section .sort.rodata.dos2errno.2,"a",@progbits
+	.globl	kDos2Errno.EAGAIN
+	.type	kDos2Errno.EAGAIN,@object
+kDos2Errno.EAGAIN:
+	.e	kNtErrorLockViolation,EAGAIN
diff --git a/libc/testlib/binequals.c b/libc/testlib/binequals.c
index 35fab15b0..0c3b145e5 100644
--- a/libc/testlib/binequals.c
+++ b/libc/testlib/binequals.c
@@ -17,6 +17,7 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/testlib/testlib.h"
 
 /**
diff --git a/net/http/encodeurl.c b/net/http/encodeurl.c
index b486a706f..ea4a79f06 100644
--- a/net/http/encodeurl.c
+++ b/net/http/encodeurl.c
@@ -18,6 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/mem/mem.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "net/http/escape.h"
 #include "net/http/url.h"
 
diff --git a/net/http/findcontenttype.c b/net/http/findcontenttype.c
index e9ac53029..defb2ab42 100644
--- a/net/http/findcontenttype.c
+++ b/net/http/findcontenttype.c
@@ -21,6 +21,7 @@
 #include "libc/intrin/bswap.h"
 #include "libc/macros.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "net/http/http.h"
 
 static const struct ContentTypeExtension {
diff --git a/net/http/gethttpheader.inc b/net/http/gethttpheader.inc
index f5fd11e93..cfff0bbbc 100644
--- a/net/http/gethttpheader.inc
+++ b/net/http/gethttpheader.inc
@@ -33,6 +33,7 @@
 #line 1 "gethttpheader.gperf"
 
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "net/http/http.h"
 #define GPERF_DOWNCASE
 #line 12 "gethttpheader.gperf"
diff --git a/net/http/gethttpmethod.inc b/net/http/gethttpmethod.inc
index 8d45d2fd9..2c475fef2 100644
--- a/net/http/gethttpmethod.inc
+++ b/net/http/gethttpmethod.inc
@@ -33,6 +33,7 @@
 #line 1 "gethttpmethod.gperf"
 
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "net/http/http.h"
 #define GPERF_DOWNCASE
 #line 12 "gethttpmethod.gperf"
diff --git a/net/http/ismimetype.c b/net/http/ismimetype.c
index 45a35b107..1d0e8c49f 100644
--- a/net/http/ismimetype.c
+++ b/net/http/ismimetype.c
@@ -17,6 +17,7 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "net/http/http.h"
 
 /**
diff --git a/net/http/parseurl.c b/net/http/parseurl.c
index dfcbbfde9..7fa60fd52 100644
--- a/net/http/parseurl.c
+++ b/net/http/parseurl.c
@@ -20,6 +20,7 @@
 #include "libc/limits.h"
 #include "libc/mem/mem.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/x/x.h"
 #include "net/http/escape.h"
 #include "net/http/url.h"
diff --git a/net/http/unchunk.c b/net/http/unchunk.c
index f87750ffc..f854244e2 100644
--- a/net/http/unchunk.c
+++ b/net/http/unchunk.c
@@ -18,6 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/macros.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/sysv/errfuns.h"
 #include "net/http/escape.h"
 #include "net/http/http.h"
diff --git a/test/libc/calls/fcntl_test.c b/test/libc/calls/fcntl_test.c
index e4c4a4ce6..5af72435b 100644
--- a/test/libc/calls/fcntl_test.c
+++ b/test/libc/calls/fcntl_test.c
@@ -30,8 +30,29 @@
 #include "libc/sysv/consts/o.h"
 #include "libc/sysv/consts/sig.h"
 #include "libc/testlib/testlib.h"
+#include "libc/thread/thread.h"
 #include "libc/x/x.h"
 
+int Lock(int fd, int type, long start, long len) {
+  int e;
+  struct flock lock = {
+      .l_type = type,
+      .l_whence = SEEK_SET,
+      .l_start = start,
+      .l_len = len,
+  };
+  e = errno;
+  while (fcntl(fd, F_SETLK, &lock)) {
+    if (errno == EAGAIN || errno == EACCES) {
+      errno = e;
+      continue;
+    } else {
+      return -1;
+    }
+  }
+  return 0;
+}
+
 char testlib_enable_tmp_setup_teardown;
 
 TEST(fcntl_getfl, testRemembersAccessMode) {
@@ -70,59 +91,15 @@ TEST(fcntl, getfd) {
   ASSERT_SYS(0, 0, close(3));
 }
 
-void OnSig(int sig) {
+TEST(fcntl, F_DUPFD_CLOEXEC) {
+  ASSERT_SYS(0, 3, open("/dev/null", O_RDWR));
+  ASSERT_SYS(0, 5, fcntl(3, F_DUPFD_CLOEXEC, 5));
+  ASSERT_SYS(0, FD_CLOEXEC, fcntl(5, F_GETFD));
+  ASSERT_SYS(0, 0, close(5));
+  ASSERT_SYS(0, 0, close(3));
 }
 
-TEST(posixAdvisoryLocks, oneProcess_unlockedFromOwnPerspectiveHuh) {
-  struct flock lock;
-  ASSERT_SYS(0, 3, open("foo", O_RDWR | O_CREAT | O_TRUNC, 0644));
-  ASSERT_SYS(0, 5, write(3, "hello", 5));
-
-  // set lock
-  lock.l_type = F_WRLCK;
-  lock.l_whence = SEEK_SET;
-  lock.l_start = 1;
-  lock.l_len = 3;
-  lock.l_pid = -2;
-  ASSERT_SYS(0, 0, fcntl(3, F_SETLK, &lock));
-  EXPECT_EQ(F_WRLCK, lock.l_type);
-  EXPECT_EQ(SEEK_SET, lock.l_whence);
-  EXPECT_EQ(1, lock.l_start);
-  EXPECT_EQ(3, lock.l_len);
-  EXPECT_EQ(-2, lock.l_pid);
-
-  ASSERT_SYS(0, 4, open("foo", O_RDWR));
-
-  // try lock
-  lock.l_type = F_WRLCK;
-  lock.l_whence = SEEK_SET;
-  lock.l_start = 0;
-  lock.l_len = 0;
-  lock.l_pid = -1;
-  ASSERT_SYS(0, 0, fcntl(4, F_SETLK, &lock));
-  EXPECT_EQ(F_WRLCK, lock.l_type);
-  EXPECT_EQ(SEEK_SET, lock.l_whence);
-  EXPECT_EQ(0, lock.l_start);
-  EXPECT_EQ(0, lock.l_len);
-  EXPECT_EQ(-1, lock.l_pid);
-
-  // get lock information
-  if (!IsWindows()) {
-    lock.l_type = F_RDLCK;
-    lock.l_whence = SEEK_SET;
-    lock.l_start = 0;
-    lock.l_len = 0;
-    lock.l_pid = -7;
-    ASSERT_SYS(0, 0, fcntl(4, F_GETLK, &lock));
-    EXPECT_EQ(F_UNLCK, lock.l_type);
-    EXPECT_EQ(SEEK_SET, lock.l_whence);
-    EXPECT_EQ(0, lock.l_start);
-    EXPECT_EQ(0, lock.l_len);
-    EXPECT_EQ(-7, lock.l_pid);  // doesn't change due to F_UNLCK
-  }
-
-  ASSERT_SYS(0, 0, close(4));
-  ASSERT_SYS(0, 0, close(3));
+void OnSig(int sig) {
 }
 
 TEST(posixAdvisoryLocks, twoProcesses) {
diff --git a/test/libc/calls/lock_test.c b/test/libc/calls/lock_test.c
new file mode 100644
index 000000000..c9f454a82
--- /dev/null
+++ b/test/libc/calls/lock_test.c
@@ -0,0 +1,186 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/calls.h"
+#include "libc/calls/struct/flock.h"
+#include "libc/dce.h"
+#include "libc/errno.h"
+#include "libc/intrin/kprintf.h"
+#include "libc/macros.internal.h"
+#include "libc/runtime/runtime.h"
+#include "libc/sysv/consts/f.h"
+#include "libc/sysv/consts/o.h"
+#include "libc/testlib/testlib.h"
+#include "libc/thread/thread.h"
+
+/**
+ * @fileoverview POSIX Advisory Locks Test
+ */
+
+#define PROCESSES  8
+#define THREADS    (IsWindows() ? 8 : 0)
+#define RATIO      3
+#define ITERATIONS 10
+
+char testlib_enable_tmp_setup_teardown;
+
+_Thread_local const char *kind;
+
+void Log(const char *fmt, ...) {
+#if 0
+  va_list va;
+  char b[512];
+  int i, n = sizeof(b);
+  va_start(va, fmt);
+  i = ksnprintf(b, n, "%s pid=%d tid=%d ", kind, getpid(), gettid());
+  i += kvsnprintf(b + i, MAX(0, n - i), fmt, va);
+  i += ksnprintf(b + i, MAX(0, n - i), "\n");
+  write(2, b, MIN(i, n));
+  va_end(va);
+#endif
+}
+
+void Lock(int fd, int type, long start, long len) {
+  int e;
+  struct flock lock = {
+      .l_type = type,
+      .l_whence = SEEK_SET,
+      .l_start = start,
+      .l_len = len,
+  };
+  e = errno;
+  while (fcntl(fd, F_SETLK, &lock)) {
+    ASSERT_TRUE(errno == EAGAIN || errno == EACCES);
+    errno = e;
+    Log("flock spinning on %d", fd);
+  }
+}
+
+void WriteLock(int fd, long start, long len) {
+  Lock(fd, F_WRLCK, start, len);
+  Log("acquired write lock on %d", fd);
+}
+
+void ReadLock(int fd, long start, long len) {
+  Lock(fd, F_RDLCK, start, len);
+  Log("acquired read lock on %d", fd);
+}
+
+void Unlock(int fd, long start, long len) {
+  Lock(fd, F_UNLCK, start, len);
+  Log("released lock on %d", fd);
+}
+
+void *Reader(void *arg) {
+  int i, j, fd;
+  char buf[10];
+  kind = arg;
+  ASSERT_NE(-1, (fd = open("db", O_RDONLY)));
+  for (j = 0; j < ITERATIONS; ++j) {
+    ReadLock(fd, 10, 10);
+    for (i = 0; i < 10; ++i) {
+      ASSERT_SYS(0, 1, pread(fd, buf + i, 1, 10 + i));
+      ASSERT_EQ(buf[0], buf[i]);
+    }
+    Unlock(fd, 10, 10);
+    sched_yield();
+  }
+  ASSERT_SYS(0, 0, close(fd));
+  return 0;
+}
+
+void *Writer(void *arg) {
+  int i, j, fd;
+  char buf[10];
+  kind = arg;
+  ASSERT_NE(-1, (fd = open("db", O_RDWR)));
+  for (j = 0; j < ITERATIONS; ++j) {
+    WriteLock(fd, 10, 10);
+    for (i = 0; i < 10; ++i) {
+      ASSERT_SYS(0, 1, pread(fd, buf + i, 1, 10 + i));
+      ASSERT_EQ(buf[0], buf[i]);
+    }
+    for (i = 0; i < 10; ++i) {
+      buf[i]++;
+    }
+    for (i = 0; i < 10; ++i) {
+      ASSERT_SYS(0, 1, pwrite(fd, buf + i, 1, 10 + i));
+    }
+    Unlock(fd, 10, 10);
+    sched_yield();
+  }
+  ASSERT_SYS(0, 0, close(fd));
+  return 0;
+}
+
+TEST(posixAdvisoryLocks, threadsAndProcessesFightingForLock) {
+  int i, rc, pid, fd, ws;
+  pthread_t th[THREADS + 1];
+
+  ASSERT_SYS(0, 3, creat("db", 0644));
+  ASSERT_SYS(0, 0, ftruncate(3, 30));
+  ASSERT_SYS(0, 0, close(3));
+
+  for (i = 0; i < THREADS; ++i) {
+    if (i % RATIO == 0) {
+      ASSERT_EQ(0, pthread_create(th + i, 0, Reader, "reader thread"));
+    } else {
+      ASSERT_EQ(0, pthread_create(th + i, 0, Writer, "writer thread"));
+    }
+  }
+
+  for (i = 0; i < PROCESSES; ++i) {
+    ASSERT_NE(-1, (rc = fork()));
+    if (!rc) {
+      if (i % RATIO == 0) {
+        Writer("writer process");
+      } else {
+        Reader("reader process");
+      }
+      _Exit(0);
+    }
+  }
+
+  ASSERT_NE(-1, (fd = open("db", O_RDWR)));
+  Lock(fd, F_WRLCK, 0, 10);
+  Lock(fd, F_WRLCK, 20, 10);
+
+  for (i = 0; i < THREADS; ++i) {
+    ASSERT_EQ(0, pthread_join(th[i], 0));
+  }
+
+  kind = "main process";
+  for (;;) {
+    int e = errno;
+    if ((pid = waitpid(0, &ws, 0)) != -1) {
+      if (WIFSIGNALED(ws)) {
+        Log("process %d terminated with %G", pid, WTERMSIG(ws));
+        testlib_incrementfailed();
+      } else if (WEXITSTATUS(ws)) {
+        Log("process %d exited with %d", pid, WEXITSTATUS(ws));
+        testlib_incrementfailed();
+      }
+    } else {
+      ASSERT_EQ(ECHILD, errno);
+      errno = e;
+      break;
+    }
+  }
+
+  ASSERT_SYS(0, 0, close(fd));
+}
diff --git a/test/libc/calls/pledge_test.c b/test/libc/calls/pledge_test.c
index b5d02d59c..beb8dfbcc 100644
--- a/test/libc/calls/pledge_test.c
+++ b/test/libc/calls/pledge_test.c
@@ -560,7 +560,7 @@ TEST(pledge_openbsd, bigSyscalls) {
 
 int LockWorker(void *arg, int tid) {
   flockfile(stdout);
-  ASSERT_EQ(gettid(), stdout->lock._owner);
+  ASSERT_EQ(gettid(), ((pthread_mutex_t *)stdout->lock)->_owner);
   funlockfile(stdout);
   return 0;
 }
diff --git a/test/libc/calls/preadv_test.c b/test/libc/calls/preadv_test.c
new file mode 100644
index 000000000..2a74a62b1
--- /dev/null
+++ b/test/libc/calls/preadv_test.c
@@ -0,0 +1,91 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/assert.h"
+#include "libc/calls/calls.h"
+#include "libc/calls/internal.h"
+#include "libc/calls/struct/iovec.h"
+#include "libc/errno.h"
+#include "libc/nt/files.h"
+#include "libc/sysv/consts/o.h"
+#include "libc/testlib/testlib.h"
+
+char testlib_enable_tmp_setup_teardown;
+
+TEST(preadv, ebadf) {
+  EXPECT_SYS(EBADF, -1, preadv(-1, 0, 0, 0));
+  EXPECT_SYS(EBADF, -1, pwritev(-1, 0, 0, 0));
+}
+
+TEST(preadv, testOneIovecWorks_itDelegatesToPread) {
+  char b1[2] = "hi";
+  struct iovec v[1] = {{b1, 2}};
+  ASSERT_SYS(0, 3, open("foo", O_RDWR | O_CREAT | O_TRUNC, 0644));
+  EXPECT_SYS(0, 2, pwritev(3, v, 1, 0));
+  b1[0] = 0;
+  b1[1] = 0;
+  EXPECT_SYS(0, 0, preadv(3, 0, 0, 0));
+  EXPECT_SYS(0, 0, pwritev(3, 0, 0, 0));
+  EXPECT_SYS(0, 2, preadv(3, v, 1, 0));
+  ASSERT_EQ('h', b1[0]);
+  ASSERT_EQ('i', b1[1]);
+  b1[0] = 0;
+  b1[1] = 0x55;
+  EXPECT_SYS(0, 1, preadv(3, v, 1, 1));
+  ASSERT_EQ('i', b1[0]);
+  ASSERT_EQ(0x55, b1[1]);
+  ASSERT_SYS(0, 0, close(3));
+}
+
+TEST(preadv, testTwoIovecWorks_itMustDoItsThing) {
+  char b1[1] = "h";
+  char b2[1] = "i";
+  struct iovec v[2] = {{b1, 1}, {b2, 1}};
+  ASSERT_SYS(0, 3, open("foo", O_RDWR | O_CREAT | O_TRUNC, 0644));
+  EXPECT_SYS(0, 2, pwritev(3, v, 2, 0));
+  b1[0] = 0;
+  b2[0] = 0;
+  EXPECT_SYS(0, 2, preadv(3, v, 2, 0));
+  ASSERT_EQ('h', b1[0]);
+  ASSERT_EQ('i', b2[0]);
+  b1[0] = 0;
+  b2[0] = 0x55;
+  EXPECT_SYS(0, 1, preadv(3, v, 2, 1));
+  ASSERT_EQ('i', b1[0]);
+  ASSERT_EQ(0x55, b2[0]);
+  ASSERT_SYS(0, 0, close(3));
+}
+
+TEST(pwritev, writePastEof_zeroExtendsFile_alsoDoesntChangeFilePointer) {
+  char b[6] = {0x55, 0x55, 0x55, 0x55, 0x55, 0x55};
+  char s[2] = "hi";
+  struct iovec v[1] = {{s, 2}};
+  ASSERT_SYS(0, 3, open("foo", O_RDWR | O_CREAT | O_TRUNC, 0644));
+  ASSERT_SYS(EINVAL, -1, pwritev(3, v, 1, -999));
+  ASSERT_SYS(0, 2, pwritev(3, v, 1, 0));
+  ASSERT_SYS(0, 2, pwritev(3, v, 1, 4));
+  ASSERT_SYS(0, 2, preadv(3, v, 1, 0));
+  ASSERT_SYS(0, 6, read(3, b, 6));
+  ASSERT_EQ('h', b[0]);
+  ASSERT_EQ('i', b[1]);
+  ASSERT_EQ(0, b[2]);
+  ASSERT_EQ(0, b[3]);
+  ASSERT_EQ('h', b[4]);
+  ASSERT_EQ('i', b[5]);
+  ASSERT_SYS(0, 0, close(3));
+}
diff --git a/test/libc/calls/test.mk b/test/libc/calls/test.mk
index 16c467504..ff00f3200 100644
--- a/test/libc/calls/test.mk
+++ b/test/libc/calls/test.mk
@@ -38,6 +38,7 @@ TEST_LIBC_CALLS_DIRECTDEPS =						\
 	LIBC_MEM							\
 	LIBC_NEXGEN32E							\
 	LIBC_STDIO							\
+	LIBC_NT_KERNEL32						\
 	LIBC_SYSV_CALLS							\
 	LIBC_RUNTIME							\
 	LIBC_STR							\
@@ -103,6 +104,9 @@ o/$(MODE)/test/libc/calls/poll_test.com.runs:				\
 o/$(MODE)/test/libc/calls/fcntl_test.com.runs:				\
 		private .PLEDGE = stdio rpath wpath cpath fattr proc flock
 
+o/$(MODE)/test/libc/calls/lock_test.com.runs:				\
+		private .PLEDGE = stdio rpath wpath cpath fattr proc flock
+
 o/$(MODE)/test/libc/calls/openbsd_test.com.runs:			\
 		private .PLEDGE = stdio rpath wpath cpath fattr proc unveil
 
diff --git a/test/libc/intrin/dos2errno_test.c b/test/libc/intrin/dos2errno_test.c
index db4b6ccda..1438bfffb 100644
--- a/test/libc/intrin/dos2errno_test.c
+++ b/test/libc/intrin/dos2errno_test.c
@@ -16,6 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/dce.h"
 #include "libc/errno.h"
 #include "libc/intrin/dos2errno.internal.h"
 #include "libc/intrin/kprintf.h"
@@ -28,4 +29,8 @@ TEST(__dos2errno, test) {
   EXPECT_EQ(0, __dos2errno(0));
   EXPECT_EQ(EACCES, __dos2errno(kNtErrorSectorNotFound));
   EXPECT_EQ(EADDRNOTAVAIL, __dos2errno(kNtErrorInvalidNetname));
+  EXPECT_EQ(EAGAIN, __dos2errno(33));
+  if (IsWindows()) {
+    EXPECT_EQ(ENOLCK, __dos2errno(kNtErrorNotLocked));
+  }
 }
diff --git a/test/libc/mem/djbsort_test.c b/test/libc/mem/djbsort_test.c
index ce7b379b0..e419a09fb 100644
--- a/test/libc/mem/djbsort_test.c
+++ b/test/libc/mem/djbsort_test.c
@@ -20,10 +20,11 @@
 #include "libc/log/log.h"
 #include "libc/macros.internal.h"
 #include "libc/mem/alg.h"
+#include "libc/mem/gc.h"
 #include "libc/mem/mem.h"
 #include "libc/nexgen32e/nexgen32e.h"
 #include "libc/nexgen32e/x86feature.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/runtime/runtime.h"
 #include "libc/stdio/rand.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
@@ -52,9 +53,9 @@ void insertionsort(int32_t *a, size_t n) {
 TEST(djbsort, test4) {
   static const int kA[] = {4, 3, 2, 1};
   n = ARRAYLEN(kA);
-  a = memcpy(gc(malloc(n * 4)), kA, n * 4);
-  b = memcpy(gc(malloc(n * 4)), kA, n * 4);
-  c = memcpy(gc(malloc(n * 4)), kA, n * 4);
+  a = memcpy(_gc(malloc(n * 4)), kA, n * 4);
+  b = memcpy(_gc(malloc(n * 4)), kA, n * 4);
+  c = memcpy(_gc(malloc(n * 4)), kA, n * 4);
   insertionsort(a, n);
   djbsort_avx2(b, n);
   djbsort(c, n);
@@ -79,9 +80,9 @@ TEST(djbsort, test64) {
       -1323943608, -1219421355, -582289873,  1062699814,
   };
   n = ARRAYLEN(kA);
-  a = memcpy(gc(malloc(n * 4)), kA, n * 4);
-  b = memcpy(gc(malloc(n * 4)), kA, n * 4);
-  c = memcpy(gc(malloc(n * 4)), kA, n * 4);
+  a = memcpy(_gc(malloc(n * 4)), kA, n * 4);
+  b = memcpy(_gc(malloc(n * 4)), kA, n * 4);
+  c = memcpy(_gc(malloc(n * 4)), kA, n * 4);
   insertionsort(a, n);
   djbsort(c, n);
   ASSERT_EQ(0, memcmp(a, c, n * 4));
@@ -91,10 +92,19 @@ TEST(djbsort, test64) {
   }
 }
 
+static int CompareInt(const void *a, const void *b) {
+  if (*(const int *)a < *(const int *)b) return -1;
+  if (*(const int *)a > *(const int *)b) return +1;
+  return 0;
+}
+
 BENCH(djbsort, bench) {
   n = 256;
-  a = gc(memalign(32, n * 4));
+  a = _gc(memalign(32, n * 4));
   EZBENCH2("insertionsort[255]", rngset(a, n * 4, rand64, -1),
            insertionsort(a, n));
   EZBENCH2("djbsort[255]", rngset(a, n * 4, rand64, -1), djbsort(a, n));
+  EZBENCH2("_intsort[255]", rngset(a, n * 4, rand64, -1), _intsort(a, n));
+  EZBENCH2("qsort[255]", rngset(a, n * 4, rand64, -1),
+           qsort(a, n, sizeof(int), CompareInt));
 }
diff --git a/test/libc/nexgen32e/kbase36_test.c b/test/libc/nexgen32e/kbase36_test.c
index 86a7e1fa5..6699c2fa1 100644
--- a/test/libc/nexgen32e/kbase36_test.c
+++ b/test/libc/nexgen32e/kbase36_test.c
@@ -16,8 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/nexgen32e/nexgen32e.h"
-#include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/testlib/testlib.h"
 
 TEST(kBase36, test) {
diff --git a/test/libc/nexgen32e/kcp437_test.c b/test/libc/nexgen32e/kcp437_test.c
index 2497ff162..abfcd9615 100644
--- a/test/libc/nexgen32e/kcp437_test.c
+++ b/test/libc/nexgen32e/kcp437_test.c
@@ -16,10 +16,9 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/nexgen32e/nexgen32e.h"
-#include "libc/str/str.h"
-#include "libc/testlib/testlib.h"
+#include "libc/str/tab.internal.h"
 #include "libc/str/unicode.h"
+#include "libc/testlib/testlib.h"
 
 TEST(kcp437, test) {
   long i;
diff --git a/test/libc/str/blake2_test.c b/test/libc/str/blake2_test.c
index cee7d1f22..bc669e6e8 100644
--- a/test/libc/str/blake2_test.c
+++ b/test/libc/str/blake2_test.c
@@ -21,6 +21,7 @@
 #include "libc/stdio/rand.h"
 #include "libc/str/blake2.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/testlib/ezbench.h"
 #include "libc/testlib/hyperion.h"
 #include "libc/testlib/testlib.h"
diff --git a/test/libc/str/strcasestr_test.c b/test/libc/str/strcasestr_test.c
index 0bd777e94..ac8d93cd8 100644
--- a/test/libc/str/strcasestr_test.c
+++ b/test/libc/str/strcasestr_test.c
@@ -16,13 +16,14 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/mem/alg.h"
-#include "libc/intrin/bits.h"
 #include "libc/dce.h"
+#include "libc/intrin/bits.h"
+#include "libc/mem/alg.h"
+#include "libc/mem/gc.internal.h"
 #include "libc/mem/mem.h"
 #include "libc/nexgen32e/x86feature.h"
-#include "libc/mem/gc.internal.h"
 #include "libc/str/internal.h"
+#include "libc/str/tab.internal.h"
 #include "libc/testlib/ezbench.h"
 #include "libc/testlib/hyperion.h"
 #include "libc/testlib/testlib.h"
diff --git a/test/tool/net/sqlite_test.c b/test/tool/net/sqlite_test.c
index dc5340790..0ef05fbf9 100644
--- a/test/tool/net/sqlite_test.c
+++ b/test/tool/net/sqlite_test.c
@@ -16,6 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/dce.h"
 #include "libc/testlib/testlib.h"
 #include "third_party/sqlite3/sqlite3.h"
 
diff --git a/third_party/chibicc/as.c b/third_party/chibicc/as.c
index 56f66d6f9..32b82b8b9 100644
--- a/third_party/chibicc/as.c
+++ b/third_party/chibicc/as.c
@@ -31,6 +31,7 @@
 #include "libc/runtime/runtime.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/sysv/consts/o.h"
 #include "libc/sysv/consts/s.h"
 #include "libc/x/x.h"
diff --git a/third_party/chibicc/tokenize.c b/third_party/chibicc/tokenize.c
index b6d213837..a0d59d415 100644
--- a/third_party/chibicc/tokenize.c
+++ b/third_party/chibicc/tokenize.c
@@ -2,6 +2,7 @@
 #include "libc/log/log.h"
 #include "libc/runtime/runtime.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "third_party/chibicc/chibicc.h"
 #include "third_party/chibicc/file.h"
 #include "third_party/chibicc/kw.h"
diff --git a/third_party/linenoise/linenoise.c b/third_party/linenoise/linenoise.c
index 5819c47ab..f98e33a36 100644
--- a/third_party/linenoise/linenoise.c
+++ b/third_party/linenoise/linenoise.c
@@ -154,6 +154,7 @@
 #include "libc/stdio/append.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/str/unicode.h"
 #include "libc/sysv/consts/fileno.h"
 #include "libc/sysv/consts/map.h"
diff --git a/third_party/lua/llock.c b/third_party/lua/llock.c
index b9eb6a9a8..992d700a4 100644
--- a/third_party/lua/llock.c
+++ b/third_party/lua/llock.c
@@ -16,6 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/thread/thread.h"
 #include "third_party/lua/lrepl.h"
 
 static pthread_mutex_t lua_repl_lock_obj;
diff --git a/third_party/python/Include/pyctype.h b/third_party/python/Include/pyctype.h
index 05ea304b3..58ad51ca4 100644
--- a/third_party/python/Include/pyctype.h
+++ b/third_party/python/Include/pyctype.h
@@ -1,7 +1,7 @@
 #ifndef Py_LIMITED_API
 #ifndef PYCTYPE_H
 #define PYCTYPE_H
-#include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 #define Py_TOLOWER(c) kToLower[255 & (c)]
 #define Py_TOUPPER(c) kToUpper[255 & (c)]
diff --git a/third_party/sqlite3/main.c b/third_party/sqlite3/main.c
index 31673e193..02e7fe6a8 100644
--- a/third_party/sqlite3/main.c
+++ b/third_party/sqlite3/main.c
@@ -3105,6 +3105,10 @@ static int openDatabase(
   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
   int i;                          /* Loop counter */
 
+  // TODO(jart): Fix SQLite.
+  extern bool __force_sqlite_to_work_until_we_can_fix_it;
+  __force_sqlite_to_work_until_we_can_fix_it = true;
+
 #ifdef SQLITE_ENABLE_API_ARMOR
   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
 #endif
diff --git a/tool/build/blinkenlights.c b/tool/build/blinkenlights.c
index 8c3d71a3c..0171519e4 100644
--- a/tool/build/blinkenlights.c
+++ b/tool/build/blinkenlights.c
@@ -59,6 +59,7 @@
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
 #include "libc/str/strwidth.h"
+#include "libc/str/tab.internal.h"
 #include "libc/str/thompike.h"
 #include "libc/str/tpdecode.internal.h"
 #include "libc/str/tpencode.internal.h"
diff --git a/tool/build/lib/cga.c b/tool/build/lib/cga.c
index 016b641ab..144d9c7f6 100644
--- a/tool/build/lib/cga.c
+++ b/tool/build/lib/cga.c
@@ -19,6 +19,7 @@
 #include "libc/fmt/itoa.h"
 #include "libc/macros.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "tool/build/lib/buffer.h"
 #include "tool/build/lib/cga.h"
 
diff --git a/tool/build/lib/isnocompressext.c b/tool/build/lib/isnocompressext.c
index d6dcf3151..3f1b60be8 100644
--- a/tool/build/lib/isnocompressext.c
+++ b/tool/build/lib/isnocompressext.c
@@ -20,6 +20,7 @@
 #include "libc/intrin/bswap.h"
 #include "libc/macros.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "tool/build/lib/isnocompressext.h"
 
 static const char kNoCompressExts[][8] = {
diff --git a/tool/build/lib/mda.c b/tool/build/lib/mda.c
index 52b9ab678..012509479 100644
--- a/tool/build/lib/mda.c
+++ b/tool/build/lib/mda.c
@@ -18,6 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/macros.internal.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "tool/build/lib/buffer.h"
 #include "tool/build/lib/mda.h"
 
diff --git a/tool/build/lz4toasm.c b/tool/build/lz4toasm.c
index 6f16ca23c..ee6eb079d 100644
--- a/tool/build/lz4toasm.c
+++ b/tool/build/lz4toasm.c
@@ -22,14 +22,15 @@
 #include "libc/log/check.h"
 #include "libc/log/log.h"
 #include "libc/macros.internal.h"
+#include "libc/mem/gc.internal.h"
 #include "libc/mem/mem.h"
 #include "libc/nexgen32e/kompressor.h"
 #include "libc/nexgen32e/lz4.h"
 #include "libc/runtime/ezmap.internal.h"
-#include "libc/mem/gc.internal.h"
 #include "libc/runtime/runtime.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/x/x.h"
 #include "third_party/getopt/getopt.h"
 
diff --git a/tool/build/pledge.c b/tool/build/pledge.c
index 937e67676..be6c47df7 100644
--- a/tool/build/pledge.c
+++ b/tool/build/pledge.c
@@ -18,6 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/assert.h"
 #include "libc/calls/calls.h"
+#include "libc/calls/copyfd.internal.h"
 #include "libc/calls/landlock.h"
 #include "libc/calls/pledge.h"
 #include "libc/calls/pledge.internal.h"
@@ -39,10 +40,9 @@
 #include "libc/intrin/safemacros.internal.h"
 #include "libc/macros.internal.h"
 #include "libc/math.h"
-#include "libc/calls/copyfd.internal.h"
+#include "libc/mem/gc.internal.h"
 #include "libc/mem/mem.h"
 #include "libc/nexgen32e/kcpuids.h"
-#include "libc/mem/gc.internal.h"
 #include "libc/runtime/runtime.h"
 #include "libc/runtime/sysconf.h"
 #include "libc/sock/sock.h"
diff --git a/tool/build/xlat.c b/tool/build/xlat.c
index 68f298597..9a6655886 100644
--- a/tool/build/xlat.c
+++ b/tool/build/xlat.c
@@ -21,11 +21,12 @@
 #include "libc/fmt/conv.h"
 #include "libc/log/check.h"
 #include "libc/math.h"
-#include "libc/mem/mem.h"
 #include "libc/mem/gc.h"
+#include "libc/mem/mem.h"
 #include "libc/runtime/runtime.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/x/xasprintf.h"
 
 /**
diff --git a/tool/decode/lib/disassemblehex.c b/tool/decode/lib/disassemblehex.c
index 4a7b0a964..e86137de8 100644
--- a/tool/decode/lib/disassemblehex.c
+++ b/tool/decode/lib/disassemblehex.c
@@ -18,6 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "tool/decode/lib/disassemblehex.h"
 
 static size_t countzeroes(const uint8_t *data, size_t size) {
diff --git a/tool/hash/crctab.c b/tool/hash/crctab.c
index a111abb5e..63da79974 100644
--- a/tool/hash/crctab.c
+++ b/tool/hash/crctab.c
@@ -16,8 +16,8 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/intrin/bits.h"
 #include "libc/fmt/conv.h"
+#include "libc/intrin/bits.h"
 #include "libc/macros.internal.h"
 #include "libc/nexgen32e/crc32.h"
 #include "libc/runtime/runtime.h"
diff --git a/tool/net/ljson.c b/tool/net/ljson.c
index efb20606a..d929b3792 100644
--- a/tool/net/ljson.c
+++ b/tool/net/ljson.c
@@ -22,6 +22,7 @@
 #include "libc/log/log.h"
 #include "libc/runtime/stack.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/str/utf16.h"
 #include "third_party/double-conversion/wrapper.h"
 #include "third_party/lua/cosmo.h"
diff --git a/tool/viz/bf.c b/tool/viz/bf.c
index 746e2e38e..454e6021d 100644
--- a/tool/viz/bf.c
+++ b/tool/viz/bf.c
@@ -25,6 +25,7 @@
 #include "libc/macros.internal.h"
 #include "libc/runtime/runtime.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/sysv/consts/o.h"
 #include "libc/sysv/consts/s.h"
 
diff --git a/tool/viz/bin2asm.c b/tool/viz/bin2asm.c
index 4e2e19457..afbcc8019 100644
--- a/tool/viz/bin2asm.c
+++ b/tool/viz/bin2asm.c
@@ -18,6 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 #define COLS 8
 
diff --git a/tool/viz/bing.c b/tool/viz/bing.c
index 48b4738d0..672637e64 100644
--- a/tool/viz/bing.c
+++ b/tool/viz/bing.c
@@ -21,6 +21,7 @@
 #include "libc/runtime/runtime.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/sysv/consts/ex.h"
 #include "libc/sysv/consts/exit.h"
 #include "libc/sysv/consts/fileno.h"
diff --git a/tool/viz/memzoom.c b/tool/viz/memzoom.c
index 4ddeb649d..b9bcf4201 100644
--- a/tool/viz/memzoom.c
+++ b/tool/viz/memzoom.c
@@ -41,6 +41,7 @@
 #include "libc/sock/struct/pollfd.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 #include "libc/str/unicode.h"
 #include "libc/sysv/consts/ex.h"
 #include "libc/sysv/consts/exit.h"
diff --git a/tool/viz/unbing.c b/tool/viz/unbing.c
index ccad3ca76..fad80b9d3 100644
--- a/tool/viz/unbing.c
+++ b/tool/viz/unbing.c
@@ -19,6 +19,7 @@
 #include "libc/calls/calls.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
+#include "libc/str/tab.internal.h"
 
 /**
  * @fileoverview UnBing: Glyphs → Binary.