diff --git a/Makefile b/Makefile
index d79899489..1580df774 100644
--- a/Makefile
+++ b/Makefile
@@ -269,7 +269,7 @@ CHECKS	 = $(foreach x,$(PKGS),$($(x)_CHECKS))
 
 bins:	$(BINS)
 check:	$(CHECKS)
-test:	$(TESTS) aarch64
+test:	$(TESTS)
 depend:	o/$(MODE)/depend
 tags:	TAGS HTAGS
 
diff --git a/examples/greenbean.c b/examples/greenbean.c
index 148203a72..7641ba57e 100644
--- a/examples/greenbean.c
+++ b/examples/greenbean.c
@@ -176,7 +176,7 @@ void *Worker(void *id) {
       // inherited by the accepted sockets, but using them also has the
       // side-effect that the listening socket fails with EAGAIN, every
       // several seconds. we can use that to our advantage to check for
-      // the ctrl-c shutdowne event; otherwise, we retry the accept call
+      // the ctrl-c shutdowne event; otherwise we retry the accept call
       continue;
     }
 
diff --git a/libc/calls/close.c b/libc/calls/close.c
index d3d30fc3a..4617184e9 100644
--- a/libc/calls/close.c
+++ b/libc/calls/close.c
@@ -91,6 +91,6 @@ int close(int fd) {
       __releasefd(fd);
     }
   }
-  STRACE("%s(%d) → %d% m", "close", fd, rc);
+  STRACE("close(%d) → %d% m", fd, rc);
   return rc;
 }
diff --git a/libc/calls/internal.h b/libc/calls/internal.h
index 871cc3007..d6a44a5d8 100644
--- a/libc/calls/internal.h
+++ b/libc/calls/internal.h
@@ -34,14 +34,6 @@ forceinline bool __isfdkind(int fd, int kind) {
   return 0 <= fd && fd < g_fds.n && g_fds.p[fd].kind == kind;
 }
 
-forceinline size_t _clampio(size_t size) {
-  if (!IsTrustworthy()) {
-    return MIN(size, 0x7ffff000);
-  } else {
-    return size;
-  }
-}
-
 int sys_close_nt(struct Fd *, int) _Hide;
 int _check_interrupts(bool, struct Fd *) _Hide;
 int sys_openat_metal(int, const char *, int, unsigned);
diff --git a/libc/calls/offset2overlap.c b/libc/calls/offset2overlap.c
deleted file mode 100644
index 0b5eb2961..000000000
--- a/libc/calls/offset2overlap.c
+++ /dev/null
@@ -1,29 +0,0 @@
-/*-*- 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 2020 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/nt/struct/overlapped.h"
-#include "libc/str/str.h"
-
-textwindows struct NtOverlapped *_offset2overlap(int64_t handle,
-                                                 int64_t opt_offset,
-                                                 struct NtOverlapped *mem) {
-  if (opt_offset == -1) return NULL;
-  bzero(mem, sizeof(struct NtOverlapped));
-  mem->Pointer = (void *)(uintptr_t)opt_offset;
-  return mem;
-}
diff --git a/libc/calls/read-nt.c b/libc/calls/read-nt.c
index d25f2c4c9..23c411b12 100644
--- a/libc/calls/read-nt.c
+++ b/libc/calls/read-nt.c
@@ -26,6 +26,7 @@
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/calls/wincrash.internal.h"
 #include "libc/intrin/strace.internal.h"
+#include "libc/macros.internal.h"
 #include "libc/nt/enum/filetype.h"
 #include "libc/nt/errors.h"
 #include "libc/nt/files.h"
@@ -37,13 +38,10 @@
 #include "libc/sysv/errfuns.h"
 
 static textwindows ssize_t sys_read_nt_impl(struct Fd *fd, void *data,
-                                            size_t size, ssize_t offset) {
-  bool32 ok;
-  int64_t p;
-  uint32_t got, avail;
-  struct NtOverlapped overlap;
+                                            size_t size, int64_t offset) {
 
-  // our terrible polling mechanism
+  // try to poll rather than block
+  uint32_t avail;
   if (GetFileType(fd->handle) == kNtFileTypePipe) {
     for (;;) {
       if (!PeekNamedPipe(fd->handle, 0, 0, 0, &avail, 0)) break;
@@ -63,19 +61,28 @@ 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));
+  // perform the read i/o operation
+  bool32 ok;
+  uint32_t got;
+  size = MIN(size, 0x7ffff000);
+  if (offset == -1) {
+    // perform simple blocking read
+    ok = ReadFile(fd->handle, data, size, &got, 0);
+  } else {
+    // perform pread()-style read at particular file offset
+    int64_t position;
+    // save file pointer which windows clobbers, even for overlapped i/o
+    if (!SetFilePointerEx(fd->handle, 0, &position, SEEK_CUR)) {
+      return __winerr();  // fd probably isn't seekable?
+    }
+    struct NtOverlapped overlap = {0};
+    overlap.Pointer = (void *)(uintptr_t)offset;
+    ok = ReadFile(fd->handle, data, size, 0, &overlap);
+    if (!ok && GetLastError() == kNtErrorIoPending) ok = true;
+    if (ok) ok = GetOverlappedResult(fd->handle, &overlap, &got, true);
+    // restore file pointer which windows clobbers, even on error
+    _unassert(SetFilePointerEx(fd->handle, position, 0, SEEK_SET));
   }
-
-  ok = ReadFile(fd->handle, data, _clampio(size), &got,
-                _offset2overlap(fd->handle, offset, &overlap));
-
-  if (offset != -1) {
-    // windows clobbers file pointer even on error
-    _npassert(SetFilePointerEx(fd->handle, p, 0, SEEK_SET));
-  }
-
   if (ok) {
     return got;
   }
@@ -93,7 +100,7 @@ static textwindows ssize_t sys_read_nt_impl(struct Fd *fd, void *data,
 }
 
 textwindows ssize_t sys_read_nt(struct Fd *fd, const struct iovec *iov,
-                                size_t iovlen, ssize_t opt_offset) {
+                                size_t iovlen, int64_t opt_offset) {
   ssize_t rc;
   uint32_t size;
   size_t i, total;
diff --git a/libc/calls/struct/iovec.internal.h b/libc/calls/struct/iovec.internal.h
index bbec95b22..a5048940a 100644
--- a/libc/calls/struct/iovec.internal.h
+++ b/libc/calls/struct/iovec.internal.h
@@ -13,7 +13,7 @@ int64_t sys_vmsplice(int, const struct iovec *, int64_t, uint32_t) _Hide;
 int64_t sys_writev(int32_t, const struct iovec *, int32_t) _Hide;
 size_t __iovec_size(const struct iovec *, size_t) _Hide;
 ssize_t WritevUninterruptible(int, struct iovec *, int);
-ssize_t sys_read_nt(struct Fd *, const struct iovec *, size_t, ssize_t) _Hide;
+ssize_t sys_read_nt(struct Fd *, const struct iovec *, size_t, int64_t) _Hide;
 ssize_t sys_readv_metal(struct Fd *, const struct iovec *, int) _Hide;
 ssize_t sys_readv_nt(struct Fd *, const struct iovec *, int) _Hide;
 ssize_t sys_readv_serial(struct Fd *, const struct iovec *, int) _Hide;
diff --git a/libc/calls/wincrash.internal.h b/libc/calls/wincrash.internal.h
index 211c15b97..9f3ceb638 100644
--- a/libc/calls/wincrash.internal.h
+++ b/libc/calls/wincrash.internal.h
@@ -1,13 +1,10 @@
 #ifndef COSMOPOLITAN_LIBC_CALLS_WINCRASH_INTERNAL_H_
 #define COSMOPOLITAN_LIBC_CALLS_WINCRASH_INTERNAL_H_
 #include "libc/nt/struct/ntexceptionpointers.h"
-#include "libc/nt/struct/overlapped.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
 unsigned __wincrash_nt(struct NtExceptionPointers *);
-struct NtOverlapped *_offset2overlap(int64_t, int64_t,
-                                     struct NtOverlapped *) _Hide;
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
diff --git a/libc/calls/write-nt.c b/libc/calls/write-nt.c
index f1454bbdc..c2c4e5e89 100644
--- a/libc/calls/write-nt.c
+++ b/libc/calls/write-nt.c
@@ -16,20 +16,20 @@
 │ 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"
 #include "libc/calls/struct/iovec.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
-#include "libc/calls/wincrash.internal.h"
 #include "libc/errno.h"
 #include "libc/intrin/strace.internal.h"
 #include "libc/intrin/weaken.h"
+#include "libc/macros.internal.h"
 #include "libc/nt/errors.h"
 #include "libc/nt/files.h"
 #include "libc/nt/runtime.h"
-#include "libc/runtime/internal.h"
+#include "libc/nt/struct/overlapped.h"
 #include "libc/runtime/runtime.h"
 #include "libc/sysv/consts/sicode.h"
 #include "libc/sysv/consts/sig.h"
@@ -37,26 +37,31 @@
 
 static textwindows ssize_t sys_write_nt_impl(int fd, void *data, size_t size,
                                              ssize_t offset) {
+
+  // perform the write i/o operation
   bool32 ok;
-  int64_t h, p;
-  uint32_t err, sent;
-  struct NtOverlapped overlap;
-
-  h = g_fds.p[fd].handle;
-
-  if (offset != -1) {
-    // windows changes the file pointer even if overlapped is passed
-    SetFilePointerEx(h, 0, &p, SEEK_CUR);
+  uint32_t sent;
+  int64_t handle;
+  handle = g_fds.p[fd].handle;
+  size = MIN(size, 0x7ffff000);
+  if (offset == -1) {
+    // perform simple blocking write
+    ok = WriteFile(handle, data, size, &sent, 0);
+  } else {
+    // perform pwrite()-style write at particular file offset
+    int64_t position;
+    // save file pointer which windows clobbers, even for overlapped i/o
+    if (!SetFilePointerEx(handle, 0, &position, SEEK_CUR)) {
+      return __winerr();  // fd probably isn't seekable?
+    }
+    struct NtOverlapped overlap = {0};
+    overlap.Pointer = (void *)(uintptr_t)offset;
+    ok = WriteFile(handle, data, size, 0, &overlap);
+    if (!ok && GetLastError() == kNtErrorIoPending) ok = true;
+    if (ok) ok = GetOverlappedResult(handle, &overlap, &sent, true);
+    // restore file pointer which windows clobbers, even on error
+    _unassert(SetFilePointerEx(handle, position, 0, SEEK_SET));
   }
-
-  ok = WriteFile(h, data, _clampio(size), &sent,
-                 _offset2overlap(h, offset, &overlap));
-
-  if (offset != -1) {
-    // windows clobbers file pointer even on error
-    SetFilePointerEx(h, p, 0, SEEK_SET);
-  }
-
   if (ok) {
     return sent;
   }
@@ -86,8 +91,6 @@ textwindows ssize_t sys_write_nt(int fd, const struct iovec *iov, size_t iovlen,
                                  ssize_t opt_offset) {
   ssize_t rc;
   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) {
diff --git a/libc/errno.h b/libc/errno.h
index 745ed5222..9a8683469 100644
--- a/libc/errno.h
+++ b/libc/errno.h
@@ -4,25 +4,35 @@
 COSMOPOLITAN_C_START_
 
 /**
- * @fileoverview System error codes.
- * @see libc/sysv/consts.sh for numbers
+ * @fileoverview System Five error codes.
+ *
+ * This file defines the `errno` global variable. When system calls
+ * (e.g. read(), write(), etc.) fail they return -1 to indicate the
+ * failure, and that is *the only* error return value. System calls
+ * also update `errno` too whenever -1 is returned (otherwise errno
+ * isn't changed) to be a non-zero value holding one of the numbers
+ * below, in order to indicate why the system call failed.
+ *
+ * There is only one exception to the above rule; some system calls
+ * are documented with the `@returnserrno` tag, which means they'll
+ * return the error number rather than stuffing it in a global. You
+ * can usually spot these system calls easily since most of them'll
+ * have names like `posix_foo()` or `pthread_bar()`.
+ *
+ * @see libc/sysv/consts.sh for assigned numbers
+ * @see libc/sysv/dos2errno.sh for multimapped numbers
  */
 
-#if defined(__GNUC__) && defined(__x86_64__) && defined(__MNO_RED_ZONE__) && \
-    !defined(__STRICT_ANSI__) && !defined(__cplusplus)
-#define errno                                                           \
-  (*({                                                                  \
-    errno_t *_ep;                                                       \
-    asm("call\t__errno_location" : "=a"(_ep) : /* no inputs */ : "cc"); \
-    _ep;                                                                \
-  }))
-#elif defined(__GNUC__) && defined(__aarch64__) && \
-    !defined(__STRICT_ANSI__) && !defined(__cplusplus)
-#define errno                             \
-  (*({                                    \
-    errno_t *_ep;                         \
-    asm("sub\t%0,x28,#1092" : "=r"(_ep)); \
-    _ep;                                  \
+#if defined(__GNUC__) && defined(__aarch64__) && !defined(__STRICT_ANSI__) && \
+    !defined(__cplusplus)
+/* this header is included by 700+ files; therefore we */
+/* hand-roll &__get_tls()->tib_errno to avoid #include */
+/* cosmopolitan uses x28 as the tls register b/c apple */
+#define errno                              \
+  (*({                                     \
+    errno_t *__ep;                         \
+    asm("sub\t%0,x28,#1092" : "=r"(__ep)); \
+    __ep;                                  \
   }))
 #else
 #define errno (*__errno_location())
@@ -493,7 +503,7 @@ extern const errno_t ENOMEDIUM;
 extern const errno_t EMEDIUMTYPE;
 
 /**
- * Inappropriate file type or format. (BSD only)
+ * Inappropriate file type or format.
  */
 extern const errno_t EFTYPE;
 
@@ -513,7 +523,6 @@ extern const errno_t EPROGUNAVAIL;
 extern const errno_t EPWROFF;
 extern const errno_t ERPCMISMATCH;
 extern const errno_t ESHLIBVERS;
-
 extern const errno_t EADV;
 extern const errno_t EBADE;
 extern const errno_t EBADFD;
@@ -558,35 +567,20 @@ extern const errno_t EXFULL;
 #define EACCES          EACCES
 #define EADDRINUSE      EADDRINUSE
 #define EADDRNOTAVAIL   EADDRNOTAVAIL
-#define EADV            EADV
 #define EAFNOSUPPORT    EAFNOSUPPORT
 #define EAGAIN          EAGAIN
 #define EALREADY        EALREADY
-#define EAUTH           EAUTH
-#define EBADARCH        EBADARCH
-#define EBADE           EBADE
-#define EBADEXEC        EBADEXEC
 #define EBADF           EBADF
-#define EBADFD          EBADFD
-#define EBADMACHO       EBADMACHO
 #define EBADMSG         EBADMSG
-#define EBADR           EBADR
-#define EBADRPC         EBADRPC
-#define EBADRQC         EBADRQC
-#define EBADSLT         EBADSLT
 #define EBUSY           EBUSY
 #define ECANCELED       ECANCELED
 #define ECHILD          ECHILD
-#define ECHRNG          ECHRNG
-#define ECOMM           ECOMM
 #define ECONNABORTED    ECONNABORTED
 #define ECONNREFUSED    ECONNREFUSED
 #define ECONNRESET      ECONNRESET
 #define EDEADLK         EDEADLK
 #define EDESTADDRREQ    EDESTADDRREQ
-#define EDEVERR         EDEVERR
 #define EDOM            EDOM
-#define EDOTDOT         EDOTDOT
 #define EDQUOT          EDQUOT
 #define EEXIST          EEXIST
 #define EFAULT          EFAULT
@@ -594,7 +588,6 @@ extern const errno_t EXFULL;
 #define EFTYPE          EFTYPE
 #define EHOSTDOWN       EHOSTDOWN
 #define EHOSTUNREACH    EHOSTUNREACH
-#define EHWPOISON       EHWPOISON
 #define EIDRM           EIDRM
 #define EILSEQ          EILSEQ
 #define EINPROGRESS     EINPROGRESS
@@ -603,20 +596,6 @@ extern const errno_t EXFULL;
 #define EIO             EIO
 #define EISCONN         EISCONN
 #define EISDIR          EISDIR
-#define EISNAM          EISNAM
-#define EKEYEXPIRED     EKEYEXPIRED
-#define EKEYREJECTED    EKEYREJECTED
-#define EKEYREVOKED     EKEYREVOKED
-#define EL2HLT          EL2HLT
-#define EL2NSYNC        EL2NSYNC
-#define EL3HLT          EL3HLT
-#define EL3RST          EL3RST
-#define ELIBACC         ELIBACC
-#define ELIBBAD         ELIBBAD
-#define ELIBEXEC        ELIBEXEC
-#define ELIBMAX         ELIBMAX
-#define ELIBSCN         ELIBSCN
-#define ELNRNG          ELNRNG
 #define ELOOP           ELOOP
 #define EMEDIUMTYPE     EMEDIUMTYPE
 #define EMFILE          EMFILE
@@ -624,29 +603,21 @@ extern const errno_t EXFULL;
 #define EMSGSIZE        EMSGSIZE
 #define EMULTIHOP       EMULTIHOP
 #define ENAMETOOLONG    ENAMETOOLONG
-#define ENAVAIL         ENAVAIL
-#define ENEEDAUTH       ENEEDAUTH
 #define ENETDOWN        ENETDOWN
 #define ENETRESET       ENETRESET
 #define ENETUNREACH     ENETUNREACH
 #define ENFILE          ENFILE
-#define ENOANO          ENOANO
-#define ENOATTR         ENOATTR
 #define ENOBUFS         ENOBUFS
-#define ENOCSI          ENOCSI
 #define ENODATA         ENODATA
 #define ENODEV          ENODEV
 #define ENOENT          ENOENT
 #define ENOEXEC         ENOEXEC
-#define ENOKEY          ENOKEY
 #define ENOLCK          ENOLCK
 #define ENOLINK         ENOLINK
 #define ENOMEDIUM       ENOMEDIUM
 #define ENOMEM          ENOMEM
 #define ENOMSG          ENOMSG
 #define ENONET          ENONET
-#define ENOPKG          ENOPKG
-#define ENOPOLICY       ENOPOLICY
 #define ENOPROTOOPT     ENOPROTOOPT
 #define ENOSPC          ENOSPC
 #define ENOSR           ENOSR
@@ -656,12 +627,10 @@ extern const errno_t EXFULL;
 #define ENOTCONN        ENOTCONN
 #define ENOTDIR         ENOTDIR
 #define ENOTEMPTY       ENOTEMPTY
-#define ENOTNAM         ENOTNAM
 #define ENOTRECOVERABLE ENOTRECOVERABLE
 #define ENOTSOCK        ENOTSOCK
 #define ENOTSUP         ENOTSUP
 #define ENOTTY          ENOTTY
-#define ENOTUNIQ        ENOTUNIQ
 #define ENXIO           ENXIO
 #define EOPNOTSUPP      EOPNOTSUPP
 #define EOVERFLOW       EOVERFLOW
@@ -669,43 +638,28 @@ extern const errno_t EXFULL;
 #define EPERM           EPERM
 #define EPFNOSUPPORT    EPFNOSUPPORT
 #define EPIPE           EPIPE
-#define EPROCLIM        EPROCLIM
-#define EPROCUNAVAIL    EPROCUNAVAIL
-#define EPROGMISMATCH   EPROGMISMATCH
-#define EPROGUNAVAIL    EPROGUNAVAIL
 #define EPROTO          EPROTO
 #define EPROTONOSUPPORT EPROTONOSUPPORT
 #define EPROTOTYPE      EPROTOTYPE
-#define EPWROFF         EPWROFF
 #define ERANGE          ERANGE
-#define EREMCHG         EREMCHG
 #define EREMOTE         EREMOTE
-#define EREMOTEIO       EREMOTEIO
 #define ERESTART        ERESTART
-#define ERFKILL         ERFKILL
 #define EROFS           EROFS
-#define ERPCMISMATCH    ERPCMISMATCH
-#define ESHLIBVERS      ESHLIBVERS
 #define ESHUTDOWN       ESHUTDOWN
 #define ESOCKTNOSUPPORT ESOCKTNOSUPPORT
 #define ESPIPE          ESPIPE
 #define ESRCH           ESRCH
-#define ESRMNT          ESRMNT
 #define ESTALE          ESTALE
-#define ESTRPIPE        ESTRPIPE
 #define ETIME           ETIME
 #define ETIMEDOUT       ETIMEDOUT
 #define ETOOMANYREFS    ETOOMANYREFS
 #define ETXTBSY         ETXTBSY
-#define EUCLEAN         EUCLEAN
-#define EUNATCH         EUNATCH
 #define EUSERS          EUSERS
 #define EWOULDBLOCK     EAGAIN
 #define EXDEV           EXDEV
-#define EXFULL          EXFULL
 
 extern errno_t __errno;
-errno_t *__errno_location(void);
+errno_t *__errno_location(void) dontthrow pureconst;
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
diff --git a/libc/nt/master.sh b/libc/nt/master.sh
index 9b6de9275..d3d1cbce7 100755
--- a/libc/nt/master.sh
+++ b/libc/nt/master.sh
@@ -3298,6 +3298,7 @@ imp	'WSCWriteNameSpaceOrder32'				WSCWriteNameSpaceOrder32				ws2_32		162
 imp	'WSCWriteProviderOrder'					WSCWriteProviderOrder					ws2_32		163
 imp	'WSCWriteProviderOrder32'				WSCWriteProviderOrder32					ws2_32		164
 imp	'WSCWriteProviderOrderEx'				WSCWriteProviderOrderEx					ws2_32		165
+imp	'__sys_socket_nt'					socket							ws2_32		0	3
 imp	'__sys_accept_nt'					accept							ws2_32		1	3	# we're using WSAAccept()
 imp	'__sys_bind_nt'						bind							ws2_32		2	3
 imp	'__sys_closesocket_nt'					closesocket						ws2_32		3	1
diff --git a/libc/runtime/fork-nt.c b/libc/runtime/fork-nt.c
index fed4583ee..e0ee91e3c 100644
--- a/libc/runtime/fork-nt.c
+++ b/libc/runtime/fork-nt.c
@@ -51,6 +51,7 @@
 #include "libc/runtime/internal.h"
 #include "libc/runtime/memtrack.internal.h"
 #include "libc/runtime/runtime.h"
+#include "libc/runtime/symbols.internal.h"
 #include "libc/str/str.h"
 #include "libc/sysv/consts/map.h"
 #include "libc/sysv/consts/o.h"
@@ -349,14 +350,20 @@ textwindows int sys_fork_nt(uint32_t dwCreationFlags) {
     }
   } else {
     rc = 0;
+    // re-apply code morphing for thread-local storage
     if (tib && _weaken(__set_tls) && _weaken(__morph_tls)) {
       _weaken(__set_tls)(tib);
       _weaken(__morph_tls)();
       __tls_enabled_set(true);
     }
+    // re-apply code morphing for synchronization nops
     if (threaded && !__threaded && _weaken(__enable_threads)) {
       _weaken(__enable_threads)();
     }
+    // re-apply code morphing for function tracing
+    if (ftrace_stackdigs) {
+      _weaken(__hook)(_weaken(ftrace_hook), _weaken(GetSymbolTable)());
+    }
   }
   if (untrackpid != -1) {
     __releasefd(untrackpid);
diff --git a/libc/runtime/ftrace-hook.S b/libc/runtime/ftrace-hook.S
index af12bcc67..84dbca1ac 100644
--- a/libc/runtime/ftrace-hook.S
+++ b/libc/runtime/ftrace-hook.S
@@ -119,4 +119,4 @@ ftrace_hook:
 1:	ret
 
 #endif /* __x86_64__ */
-	.endfn	ftrace_hook,globl
+	.endfn	ftrace_hook,globl,hidden
diff --git a/libc/runtime/ftrace_install.c b/libc/runtime/ftrace_install.c
index e3dbeb82f..15e536d0a 100644
--- a/libc/runtime/ftrace_install.c
+++ b/libc/runtime/ftrace_install.c
@@ -23,8 +23,6 @@
 #include "libc/runtime/stack.h"
 #include "libc/runtime/symbols.internal.h"
 
-void ftrace_hook(void);
-
 textstartup int ftrace_install(void) {
   if (GetSymbolTable()) {
     ftrace_stackdigs = LengthInt64Thousands(GetStackSize());
diff --git a/libc/runtime/internal.h b/libc/runtime/internal.h
index afcb789b9..870ebcfc5 100644
--- a/libc/runtime/internal.h
+++ b/libc/runtime/internal.h
@@ -33,6 +33,7 @@ extern unsigned char _tls_content[] __attribute__((__weak__));
 
 void _init(void) _Hide;
 int ftrace_init(void) _Hide;
+void ftrace_hook(void) _Hide;
 void __morph_tls(void) _Hide;
 void __enable_tls(void) _Hide;
 void __enable_threads(void) _Hide;
diff --git a/libc/runtime/morph.greg.c b/libc/runtime/morph.greg.c
index 22082ca65..538b91ba7 100644
--- a/libc/runtime/morph.greg.c
+++ b/libc/runtime/morph.greg.c
@@ -18,6 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #define ShouldUseMsabiAttribute() 1
 #include "ape/sections.internal.h"
+#include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
 #include "libc/calls/struct/sigset.h"
 #include "libc/dce.h"
@@ -36,24 +37,7 @@
 
 __msabi extern typeof(VirtualProtect) *const __imp_VirtualProtect;
 
-#ifdef __aarch64__
-static privileged void __aarch64_sigprocmask(int how, const sigset_t *set,
-                                             sigset_t *oldset) {
-  register int r0 asm("x0") = how;
-  register long r1 asm("x1") = (long)set;
-  register long r2 asm("x2") = (long)oldset;
-  register long r3 asm("x3") = 8;
-  register long r8 asm("x8") = __NR_sigprocmask;
-  register long r16 asm("x16") = __NR_sigprocmask;
-  asm volatile("svc\t0"
-               : "+r"(r0)
-               : "r"(r1), "r"(r2), "r"(r3), "r"(r8), "r"(r16)
-               : "memory");
-}
-#endif
-
-static privileged void __morph_mprotect(void *addr, size_t size, int prot,
-                                        int ntprot) {
+__funline void __morph_mprotect(void *addr, size_t size, int prot, int ntprot) {
 #ifdef __x86_64__
   bool cf;
   int ax, dx;
@@ -69,8 +53,11 @@ static privileged void __morph_mprotect(void *addr, size_t size, int prot,
     if (ax == -EPERM) {
       kprintf("error: need pledge(prot_exec) permission to code morph\n");
     }
+    if (ax < 0) {
+      kprintf("error: __morph_mprotect(%p, %#zx, %d) failed: errno=%d\n", addr,
+              size, prot, -ax);
+    }
 #endif
-    if (ax) notpossible;
   } else {
     __imp_VirtualProtect(addr, size, ntprot, &op);
   }
@@ -97,27 +84,6 @@ privileged void __morph_begin(sigset_t *save) {
   bool cf;
   intptr_t dx;
   sigset_t ss = {{-1, -1}};
-#ifdef __x86_64__
-  if (IsOpenbsd()) {
-    asm volatile(CFLAG_ASM("syscall")
-                 : CFLAG_CONSTRAINT(cf), "=a"(ax), "=d"(dx)
-                 : "1"(__NR_sigprocmask), "D"(SIG_BLOCK), "S"(-1u)
-                 : "rcx", "r8", "r9", "r10", "r11", "memory");
-    save->__bits[0] = ax & 0xffffffff;
-    if (cf) notpossible;
-  } else if (!IsWindows() && !IsMetal()) {
-    asm volatile("mov\t$8,%%r10d\n\t"
-                 "syscall"
-                 : "=a"(ax), "=d"(dx)
-                 : "0"(__NR_sigprocmask), "D"(SIG_BLOCK), "S"(&ss), "1"(save)
-                 : "rcx", "r8", "r9", "r10", "r11", "memory", "cc");
-    if (ax) notpossible;
-  }
-#elif defined(__aarch64__)
-  __aarch64_sigprocmask(SIG_BLOCK, &ss, save);
-#else
-#error "unsupported architecture"
-#endif
   __morph_mprotect(__executable_start, __privileged_start - __executable_start,
                    PROT_READ | PROT_WRITE, kNtPageWritecopy);
 }
@@ -131,24 +97,4 @@ privileged void __morph_end(sigset_t *save) {
   bool cf;
   __morph_mprotect(__executable_start, __privileged_start - __executable_start,
                    PROT_READ | PROT_EXEC, kNtPageExecuteRead);
-#ifdef __x86_64__
-  if (IsOpenbsd()) {
-    asm volatile(CFLAG_ASM("syscall")
-                 : CFLAG_CONSTRAINT(cf), "=a"(ax), "=d"(dx)
-                 : "1"(__NR_sigprocmask), "D"(SIG_SETMASK), "S"(save->__bits[0])
-                 : "rcx", "r8", "r9", "r10", "r11", "memory");
-    if (cf) notpossible;
-  } else if (!IsWindows() && !IsMetal()) {
-    asm volatile("mov\t$8,%%r10d\n\t"
-                 "syscall"
-                 : "=a"(ax), "=d"(dx)
-                 : "0"(__NR_sigprocmask), "D"(SIG_SETMASK), "S"(save), "1"(0L)
-                 : "rcx", "r8", "r9", "r10", "r11", "memory", "cc");
-    if (ax) notpossible;
-  }
-#elif defined(__aarch64__)
-  __aarch64_sigprocmask(SIG_SETMASK, save, 0);
-#else
-#error "unsupported architecture"
-#endif
 }
diff --git a/libc/runtime/opensymboltable.greg.c b/libc/runtime/opensymboltable.greg.c
index 661d95df6..4a3016a58 100644
--- a/libc/runtime/opensymboltable.greg.c
+++ b/libc/runtime/opensymboltable.greg.c
@@ -100,8 +100,14 @@ static struct SymbolTable *OpenSymbolTableImpl(const char *filename) {
   for (j = i = 0; i < m; ++i) {
     sym = symtab + (stp[i] & 0x7fffffff);
     x = stp[i] >> 32;
-    if (j && x == t->symbols[j - 1].x) --j;
-    if (j && t->symbols[j - 1].y >= x) t->symbols[j - 1].y = x - 1;
+    if (j && x == t->symbols[j - 1].x) {
+      // when two symbols have an identical address value, favor the
+      // symbol that was defined earlier in the elf data structures.
+      continue;
+    }
+    if (j && t->symbols[j - 1].y >= x) {
+      t->symbols[j - 1].y = x - 1;
+    }
     t->names[j] = sym->st_name;
     t->symbols[j].x = x;
     if (sym->st_size) {
diff --git a/libc/sysv/errno.c b/libc/sysv/errno.c
index 53c1f9778..1a5889c5d 100644
--- a/libc/sysv/errno.c
+++ b/libc/sysv/errno.c
@@ -17,6 +17,7 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/errno.h"
+#include "libc/thread/tls.h"
 
 /**
  * Global variable for last error.
@@ -31,3 +32,14 @@
  * @see	__errno_location() stable abi
  */
 errno_t __errno;
+
+/**
+ * Returns address of `errno` variable.
+ */
+errno_t *__errno_location(void) {
+  if (__tls_enabled) {
+    return &__get_tls()->tib_errno;
+  } else {
+    return &__errno;
+  }
+}
diff --git a/libc/sysv/errno_location.greg.c b/libc/sysv/errno_location.greg.c
deleted file mode 100644
index 93246f2e5..000000000
--- a/libc/sysv/errno_location.greg.c
+++ /dev/null
@@ -1,29 +0,0 @@
-/*-*- 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/thread/tls2.h"
-
-extern errno_t __errno;
-
-/**
- * Returns address of errno variable.
- */
-nocallersavedregisters errno_t *(__errno_location)(void) {
-  if (!__tls_enabled) return &__errno;
-  return &__get_tls_privileged()->tib_errno;
-}
diff --git a/libc/sysv/sysv.mk b/libc/sysv/sysv.mk
index 78bf083c6..ca89ad843 100644
--- a/libc/sysv/sysv.mk
+++ b/libc/sysv/sysv.mk
@@ -40,7 +40,6 @@ LIBC_SYSV_A_FILES :=					\
 	libc/sysv/restorert.S				\
 	libc/sysv/syscall.S				\
 	libc/sysv/systemfive.S				\
-	libc/sysv/errno_location.greg.c			\
 	libc/sysv/sysret.c				\
 	libc/sysv/errno.c				\
 	libc/sysv/errfun.S				\