syscall: support POSIX semantics for Linux syscalls

This change adds two new methods for invoking system calls
under Linux: syscall.AllThreadsSyscall() and
syscall.AllThreadsSyscall6().

These system call wrappers ensure that all OSThreads mirror
a common system call. The wrappers serialize execution of the
runtime to ensure no race conditions where any Go code observes
a non-atomic OS state change. As such, the syscalls have
higher runtime overhead than regular system calls, and only
need to be used where such thread (or 'm' in the parlance
of the runtime sources) consistency is required.

The new support is used to enable these functions under Linux:

  syscall.Setegid(), syscall.Seteuid(), syscall.Setgroups(),
  syscall.Setgid(), syscall.Setregid(), syscall.Setreuid(),
  syscall.Setresgid(), syscall.Setresuid() and syscall.Setuid().

They work identically to their glibc counterparts.

Extensive discussion of the background issue addressed in this
patch can be found here:

   https://github.com/golang/go/issues/1435

In the case where cgo is used, the C runtime can launch pthreads that
are not managed by the Go runtime. As such, the added
syscall.AllThreadsSyscall*() return ENOTSUP when cgo is enabled.
However, for the 9 syscall.Set*() functions listed above, when cgo is
active, these functions redirect to invoke their C.set*() equivalents
in glibc, which wraps the raw system calls with a nptl:setxid fixup
mechanism. This achieves POSIX semantics for these functions in the
combined Go and C runtime.

As a side note, the glibc/nptl:setxid support (2019-11-30) does not
extend to all security related system calls under Linux so using
native Go (CGO_ENABLED=0) and these AllThreadsSyscall*()s, where
needed, will yield more well defined/consistent behavior over all
threads of a Go program. That is, using the
syscall.AllThreadsSyscall*() wrappers for things like setting state
through SYS_PRCTL and SYS_CAPSET etc.

Fixes #1435

Change-Id: Ib1a3e16b9180f64223196a32fc0f9dce14d9105c
Reviewed-on: https://go-review.googlesource.com/c/go/+/210639
Trust: Emmanuel Odeke <emm.odeke@gmail.com>
Trust: Ian Lance Taylor <iant@golang.org>
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Austin Clements <austin@google.com>

32 files changed, 1020 insertions, 660 deletions

diff --git a/misc/cgo/test/cgo_linux_test.go b/misc/cgo/test/cgo_linux_test.go
index 7b56e11a27..a9746b552e 100644
--- a/misc/cgo/test/cgo_linux_test.go
+++ b/misc/cgo/test/cgo_linux_test.go
@@ -15,5 +15,6 @@ func TestSetgid(t *testing.T) {
 	}
 	testSetgid(t)
 }
+func Test1435(t *testing.T)    { test1435(t) }
 func Test6997(t *testing.T)    { test6997(t) }
 func TestBuildID(t *testing.T) { testBuildID(t) }
diff --git a/misc/cgo/test/issue1435.go b/misc/cgo/test/issue1435.go
new file mode 100644
index 0000000000..155d33baff
--- /dev/null
+++ b/misc/cgo/test/issue1435.go
@@ -0,0 +1,152 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build linux,cgo
+
+package cgotest
+
+import (
+	"fmt"
+	"io/ioutil"
+	"strings"
+	"syscall"
+	"testing"
+)
+
+// #include <stdio.h>
+// #include <stdlib.h>
+// #include <pthread.h>
+// #include <unistd.h>
+// #include <sys/types.h>
+//
+// pthread_t *t = NULL;
+// pthread_mutex_t mu;
+// int nts = 0;
+// int all_done = 0;
+//
+// static void *aFn(void *vargp) {
+//   int done = 0;
+//   while (!done) {
+//     usleep(100);
+//     pthread_mutex_lock(&mu);
+//     done = all_done;
+//     pthread_mutex_unlock(&mu);
+//   }
+//   return NULL;
+// }
+//
+// void trial(int argc) {
+//   int i;
+//   nts = argc;
+//   t = calloc(nts, sizeof(pthread_t));
+//   pthread_mutex_init(&mu, NULL);
+//   for (i = 0; i < nts; i++) {
+//     pthread_create(&t[i], NULL, aFn, NULL);
+//   }
+// }
+//
+// void cleanup(void) {
+//   int i;
+//   pthread_mutex_lock(&mu);
+//   all_done = 1;
+//   pthread_mutex_unlock(&mu);
+//   for (i = 0; i < nts; i++) {
+//     pthread_join(t[i], NULL);
+//   }
+//   pthread_mutex_destroy(&mu);
+//   free(t);
+// }
+import "C"
+
+// compareStatus is used to confirm the contents of the thread
+// specific status files match expectations.
+func compareStatus(filter, expect string) error {
+	expected := filter + "\t" + expect
+	pid := syscall.Getpid()
+	fs, err := ioutil.ReadDir(fmt.Sprintf("/proc/%d/task", pid))
+	if err != nil {
+		return fmt.Errorf("unable to find %d tasks: %v", pid, err)
+	}
+	for _, f := range fs {
+		tf := fmt.Sprintf("/proc/%s/status", f.Name())
+		d, err := ioutil.ReadFile(tf)
+		if err != nil {
+			return fmt.Errorf("unable to read %q: %v", tf, err)
+		}
+		lines := strings.Split(string(d), "\n")
+		for _, line := range lines {
+			if strings.HasPrefix(line, filter) {
+				if line != expected {
+					return fmt.Errorf("%s %s (bad)\n", tf, line)
+				}
+				break
+			}
+		}
+	}
+	return nil
+}
+
+// test1435 test 9 glibc implemented setuid/gid syscall functions are
+// mapped.  This test is a slightly more expansive test than that of
+// src/syscall/syscall_linux_test.go:TestSetuidEtc() insofar as it
+// launches concurrent threads from C code via CGo and validates that
+// they are subject to the system calls being tested. For the actual
+// Go functionality being tested here, the syscall_linux_test version
+// is considered authoritative, but non-trivial improvements to that
+// should be mirrored here.
+func test1435(t *testing.T) {
+	if syscall.Getuid() != 0 {
+		t.Skip("skipping root only test")
+	}
+
+	// Launch some threads in C.
+	const cts = 5
+	C.trial(cts)
+	defer C.cleanup()
+
+	vs := []struct {
+		call           string
+		fn             func() error
+		filter, expect string
+	}{
+		{call: "Setegid(1)", fn: func() error { return syscall.Setegid(1) }, filter: "Gid:", expect: "0\t1\t0\t1"},
+		{call: "Setegid(0)", fn: func() error { return syscall.Setegid(0) }, filter: "Gid:", expect: "0\t0\t0\t0"},
+
+		{call: "Seteuid(1)", fn: func() error { return syscall.Seteuid(1) }, filter: "Uid:", expect: "0\t1\t0\t1"},
+		{call: "Setuid(0)", fn: func() error { return syscall.Setuid(0) }, filter: "Uid:", expect: "0\t0\t0\t0"},
+
+		{call: "Setgid(1)", fn: func() error { return syscall.Setgid(1) }, filter: "Gid:", expect: "1\t1\t1\t1"},
+		{call: "Setgid(0)", fn: func() error { return syscall.Setgid(0) }, filter: "Gid:", expect: "0\t0\t0\t0"},
+
+		{call: "Setgroups([]int{0,1,2,3})", fn: func() error { return syscall.Setgroups([]int{0, 1, 2, 3}) }, filter: "Groups:", expect: "0 1 2 3 "},
+		{call: "Setgroups(nil)", fn: func() error { return syscall.Setgroups(nil) }, filter: "Groups:", expect: " "},
+		{call: "Setgroups([]int{0})", fn: func() error { return syscall.Setgroups([]int{0}) }, filter: "Groups:", expect: "0 "},
+
+		{call: "Setregid(101,0)", fn: func() error { return syscall.Setregid(101, 0) }, filter: "Gid:", expect: "101\t0\t0\t0"},
+		{call: "Setregid(0,102)", fn: func() error { return syscall.Setregid(0, 102) }, filter: "Gid:", expect: "0\t102\t102\t102"},
+		{call: "Setregid(0,0)", fn: func() error { return syscall.Setregid(0, 0) }, filter: "Gid:", expect: "0\t0\t0\t0"},
+
+		{call: "Setreuid(1,0)", fn: func() error { return syscall.Setreuid(1, 0) }, filter: "Uid:", expect: "1\t0\t0\t0"},
+		{call: "Setreuid(0,2)", fn: func() error { return syscall.Setreuid(0, 2) }, filter: "Uid:", expect: "0\t2\t2\t2"},
+		{call: "Setreuid(0,0)", fn: func() error { return syscall.Setreuid(0, 0) }, filter: "Uid:", expect: "0\t0\t0\t0"},
+
+		{call: "Setresgid(101,0,102)", fn: func() error { return syscall.Setresgid(101, 0, 102) }, filter: "Gid:", expect: "101\t0\t102\t0"},
+		{call: "Setresgid(0,102,101)", fn: func() error { return syscall.Setresgid(0, 102, 101) }, filter: "Gid:", expect: "0\t102\t101\t102"},
+		{call: "Setresgid(0,0,0)", fn: func() error { return syscall.Setresgid(0, 0, 0) }, filter: "Gid:", expect: "0\t0\t0\t0"},
+
+		{call: "Setresuid(1,0,2)", fn: func() error { return syscall.Setresuid(1, 0, 2) }, filter: "Uid:", expect: "1\t0\t2\t0"},
+		{call: "Setresuid(0,2,1)", fn: func() error { return syscall.Setresuid(0, 2, 1) }, filter: "Uid:", expect: "0\t2\t1\t2"},
+		{call: "Setresuid(0,0,0)", fn: func() error { return syscall.Setresuid(0, 0, 0) }, filter: "Uid:", expect: "0\t0\t0\t0"},
+	}
+
+	for i, v := range vs {
+		if err := v.fn(); err != nil {
+			t.Errorf("[%d] %q failed: %v", i, v.call, err)
+			continue
+		}
+		if err := compareStatus(v.filter, v.expect); err != nil {
+			t.Errorf("[%d] %q comparison: %v", i, v.call, err)
+		}
+	}
+}
diff --git a/src/runtime/cgo/linux.go b/src/runtime/cgo/linux.go
new file mode 100644
index 0000000000..76c0192c20
--- /dev/null
+++ b/src/runtime/cgo/linux.go
@@ -0,0 +1,74 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Linux system call wrappers that provide POSIX semantics through the
+// corresponding cgo->libc (nptl) wrappers for various system calls.
+
+// +build linux
+
+package cgo
+
+import "unsafe"
+
+// Each of the following entries is needed to ensure that the
+// syscall.syscall_linux code can conditionally call these
+// function pointers:
+//
+//  1. find the C-defined function start
+//  2. force the local byte alias to be mapped to that location
+//  3. map the Go pointer to the function to the syscall package
+
+//go:cgo_import_static _cgo_libc_setegid
+//go:linkname _cgo_libc_setegid _cgo_libc_setegid
+//go:linkname cgo_libc_setegid syscall.cgo_libc_setegid
+var _cgo_libc_setegid byte
+var cgo_libc_setegid = unsafe.Pointer(&_cgo_libc_setegid)
+
+//go:cgo_import_static _cgo_libc_seteuid
+//go:linkname _cgo_libc_seteuid _cgo_libc_seteuid
+//go:linkname cgo_libc_seteuid syscall.cgo_libc_seteuid
+var _cgo_libc_seteuid byte
+var cgo_libc_seteuid = unsafe.Pointer(&_cgo_libc_seteuid)
+
+//go:cgo_import_static _cgo_libc_setregid
+//go:linkname _cgo_libc_setregid _cgo_libc_setregid
+//go:linkname cgo_libc_setregid syscall.cgo_libc_setregid
+var _cgo_libc_setregid byte
+var cgo_libc_setregid = unsafe.Pointer(&_cgo_libc_setregid)
+
+//go:cgo_import_static _cgo_libc_setresgid
+//go:linkname _cgo_libc_setresgid _cgo_libc_setresgid
+//go:linkname cgo_libc_setresgid syscall.cgo_libc_setresgid
+var _cgo_libc_setresgid byte
+var cgo_libc_setresgid = unsafe.Pointer(&_cgo_libc_setresgid)
+
+//go:cgo_import_static _cgo_libc_setresuid
+//go:linkname _cgo_libc_setresuid _cgo_libc_setresuid
+//go:linkname cgo_libc_setresuid syscall.cgo_libc_setresuid
+var _cgo_libc_setresuid byte
+var cgo_libc_setresuid = unsafe.Pointer(&_cgo_libc_setresuid)
+
+//go:cgo_import_static _cgo_libc_setreuid
+//go:linkname _cgo_libc_setreuid _cgo_libc_setreuid
+//go:linkname cgo_libc_setreuid syscall.cgo_libc_setreuid
+var _cgo_libc_setreuid byte
+var cgo_libc_setreuid = unsafe.Pointer(&_cgo_libc_setreuid)
+
+//go:cgo_import_static _cgo_libc_setgroups
+//go:linkname _cgo_libc_setgroups _cgo_libc_setgroups
+//go:linkname cgo_libc_setgroups syscall.cgo_libc_setgroups
+var _cgo_libc_setgroups byte
+var cgo_libc_setgroups = unsafe.Pointer(&_cgo_libc_setgroups)
+
+//go:cgo_import_static _cgo_libc_setgid
+//go:linkname _cgo_libc_setgid _cgo_libc_setgid
+//go:linkname cgo_libc_setgid syscall.cgo_libc_setgid
+var _cgo_libc_setgid byte
+var cgo_libc_setgid = unsafe.Pointer(&_cgo_libc_setgid)
+
+//go:cgo_import_static _cgo_libc_setuid
+//go:linkname _cgo_libc_setuid _cgo_libc_setuid
+//go:linkname cgo_libc_setuid syscall.cgo_libc_setuid
+var _cgo_libc_setuid byte
+var cgo_libc_setuid = unsafe.Pointer(&_cgo_libc_setuid)
diff --git a/src/runtime/cgo/linux_syscall.c b/src/runtime/cgo/linux_syscall.c
new file mode 100644
index 0000000000..c8e91918a1
--- /dev/null
+++ b/src/runtime/cgo/linux_syscall.c
@@ -0,0 +1,85 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build linux
+
+#ifndef _GNU_SOURCE // setres[ug]id() API.
+#define _GNU_SOURCE
+#endif
+
+#include <grp.h>
+#include <sys/types.h>
+#include <sys/unistd.h>
+#include <errno.h>
+#include "libcgo.h"
+
+/*
+ * Assumed POSIX compliant libc system call wrappers. For linux, the
+ * glibc/nptl/setxid mechanism ensures that POSIX semantics are
+ * honored for all pthreads (by default), and this in turn with cgo
+ * ensures that all Go threads launched with cgo are kept in sync for
+ * these function calls.
+ */
+
+// argset_t matches runtime/cgocall.go:argset.
+typedef struct {
+	uintptr_t* args;
+	uintptr_t retval;
+} argset_t;
+
+// libc backed posix-compliant syscalls.
+
+#define SET_RETVAL(fn) \
+  uintptr_t ret = (uintptr_t) fn ; \
+  if (ret == -1) {                 \
+    x->retval = (uintptr_t) errno; \
+  } else                           \
+    x->retval = ret
+
+void
+_cgo_libc_setegid(argset_t* x) {
+	SET_RETVAL(setegid((gid_t) x->args[0]));
+}
+
+void
+_cgo_libc_seteuid(argset_t* x) {
+	SET_RETVAL(seteuid((uid_t) x->args[0]));
+}
+
+void
+_cgo_libc_setgid(argset_t* x) {
+	SET_RETVAL(setgid((gid_t) x->args[0]));
+}
+
+void
+_cgo_libc_setgroups(argset_t* x) {
+	SET_RETVAL(setgroups((size_t) x->args[0], (const gid_t *) x->args[1]));
+}
+
+void
+_cgo_libc_setregid(argset_t* x) {
+	SET_RETVAL(setregid((gid_t) x->args[0], (gid_t) x->args[1]));
+}
+
+void
+_cgo_libc_setresgid(argset_t* x) {
+	SET_RETVAL(setresgid((gid_t) x->args[0], (gid_t) x->args[1],
+			     (gid_t) x->args[2]));
+}
+
+void
+_cgo_libc_setresuid(argset_t* x) {
+	SET_RETVAL(setresuid((uid_t) x->args[0], (uid_t) x->args[1],
+			     (uid_t) x->args[2]));
+}
+
+void
+_cgo_libc_setreuid(argset_t* x) {
+	SET_RETVAL(setreuid((uid_t) x->args[0], (uid_t) x->args[1]));
+}
+
+void
+_cgo_libc_setuid(argset_t* x) {
+	SET_RETVAL(setuid((uid_t) x->args[0]));
+}
diff --git a/src/runtime/cgocall.go b/src/runtime/cgocall.go
index 0b69ff3233..7ab42a0ed0 100644
--- a/src/runtime/cgocall.go
+++ b/src/runtime/cgocall.go
@@ -93,6 +93,22 @@ import (
 // Length must match arg.Max in x_cgo_callers in runtime/cgo/gcc_traceback.c.
 type cgoCallers [32]uintptr
 
+// argset matches runtime/cgo/linux_syscall.c:argset_t
+type argset struct {
+	args   unsafe.Pointer
+	retval uintptr
+}
+
+// wrapper for syscall package to call cgocall for libc (cgo) calls.
+//go:linkname syscall_cgocaller syscall.cgocaller
+//go:nosplit
+//go:uintptrescapes
+func syscall_cgocaller(fn unsafe.Pointer, args ...uintptr) uintptr {
+	as := argset{args: unsafe.Pointer(&args[0])}
+	cgocall(fn, unsafe.Pointer(&as))
+	return as.retval
+}
+
 // Call from Go to C.
 //
 // This must be nosplit because it's used for syscalls on some
diff --git a/src/runtime/proc.go b/src/runtime/proc.go
index d088b969c8..aeacb23391 100644
--- a/src/runtime/proc.go
+++ b/src/runtime/proc.go
@@ -137,6 +137,10 @@ func main() {
 	mainStarted = true
 
 	if GOARCH != "wasm" { // no threads on wasm yet, so no sysmon
+		// For runtime_syscall_doAllThreadsSyscall, we
+		// register sysmon is not ready for the world to be
+		// stopped.
+		atomic.Store(&sched.sysmonStarting, 1)
 		systemstack(func() {
 			newm(sysmon, nil, -1)
 		})
@@ -153,6 +157,7 @@ func main() {
 	if g.m != &m0 {
 		throw("runtime.main not on m0")
 	}
+	m0.doesPark = true
 
 	// Record when the world started.
 	// Must be before doInit for tracing init.
@@ -1226,6 +1231,21 @@ func mstartm0() {
 	initsig(false)
 }
 
+// mPark causes a thread to park itself - temporarily waking for
+// fixups but otherwise waiting to be fully woken. This is the
+// only way that m's should park themselves.
+//go:nosplit
+func mPark() {
+	g := getg()
+	for {
+		notesleep(&g.m.park)
+		noteclear(&g.m.park)
+		if !mDoFixup() {
+			return
+		}
+	}
+}
+
 // mexit tears down and exits the current thread.
 //
 // Don't call this directly to exit the thread, since it must run at
@@ -1257,7 +1277,7 @@ func mexit(osStack bool) {
 		sched.nmfreed++
 		checkdead()
 		unlock(&sched.lock)
-		notesleep(&m.park)
+		mPark()
 		throw("locked m0 woke up")
 	}
 
@@ -1424,6 +1444,127 @@ func forEachP(fn func(*p)) {
 	releasem(mp)
 }
 
+// syscall_runtime_doAllThreadsSyscall serializes Go execution and
+// executes a specified fn() call on all m's.
+//
+// The boolean argument to fn() indicates whether the function's
+// return value will be consulted or not. That is, fn(true) should
+// return true if fn() succeeds, and fn(true) should return false if
+// it failed. When fn(false) is called, its return status will be
+// ignored.
+//
+// syscall_runtime_doAllThreadsSyscall first invokes fn(true) on a
+// single, coordinating, m, and only if it returns true does it go on
+// to invoke fn(false) on all of the other m's known to the process.
+//
+//go:linkname syscall_runtime_doAllThreadsSyscall syscall.runtime_doAllThreadsSyscall
+func syscall_runtime_doAllThreadsSyscall(fn func(bool) bool) {
+	if iscgo {
+		panic("doAllThreadsSyscall not supported with cgo enabled")
+	}
+	if fn == nil {
+		return
+	}
+	for atomic.Load(&sched.sysmonStarting) != 0 {
+		osyield()
+	}
+	stopTheWorldGC("doAllThreadsSyscall")
+	if atomic.Load(&newmHandoff.haveTemplateThread) != 0 {
+		// Ensure that there are no in-flight thread
+		// creations: don't want to race with allm.
+		lock(&newmHandoff.lock)
+		for !newmHandoff.waiting {
+			unlock(&newmHandoff.lock)
+			osyield()
+			lock(&newmHandoff.lock)
+		}
+		unlock(&newmHandoff.lock)
+	}
+	if netpollinited() {
+		netpollBreak()
+	}
+	_g_ := getg()
+	if raceenabled {
+		// For m's running without racectx, we loan out the
+		// racectx of this call.
+		lock(&mFixupRace.lock)
+		mFixupRace.ctx = _g_.racectx
+		unlock(&mFixupRace.lock)
+	}
+	if ok := fn(true); ok {
+		tid := _g_.m.procid
+		for mp := allm; mp != nil; mp = mp.alllink {
+			if mp.procid == tid {
+				// This m has already completed fn()
+				// call.
+				continue
+			}
+			// Be wary of mp's without procid values if
+			// they are known not to park. If they are
+			// marked as parking with a zero procid, then
+			// they will be racing with this code to be
+			// allocated a procid and we will annotate
+			// them with the need to execute the fn when
+			// they acquire a procid to run it.
+			if mp.procid == 0 && !mp.doesPark {
+				// Reaching here, we are either
+				// running Windows, or cgo linked
+				// code. Neither of which are
+				// currently supported by this API.
+				throw("unsupported runtime environment")
+			}
+			// stopTheWorldGC() doesn't guarantee stopping
+			// all the threads, so we lock here to avoid
+			// the possibility of racing with mp.
+			lock(&mp.mFixup.lock)
+			mp.mFixup.fn = fn
+			if mp.doesPark {
+				// For non-service threads this will
+				// cause the wakeup to be short lived
+				// (once the mutex is unlocked). The
+				// next real wakeup will occur after
+				// startTheWorldGC() is called.
+				notewakeup(&mp.park)
+			}
+			unlock(&mp.mFixup.lock)
+		}
+		for {
+			done := true
+			for mp := allm; done && mp != nil; mp = mp.alllink {
+				if mp.procid == tid {
+					continue
+				}
+				lock(&mp.mFixup.lock)
+				done = done && (mp.mFixup.fn == nil)
+				unlock(&mp.mFixup.lock)
+			}
+			if done {
+				break
+			}
+			// if needed force sysmon and/or newmHandoff to wakeup.
+			lock(&sched.lock)
+			if atomic.Load(&sched.sysmonwait) != 0 {
+				atomic.Store(&sched.sysmonwait, 0)
+				notewakeup(&sched.sysmonnote)
+			}
+			unlock(&sched.lock)
+			lock(&newmHandoff.lock)
+			if newmHandoff.waiting {
+				newmHandoff.waiting = false
+				notewakeup(&newmHandoff.wake)
+			}
+			unlock(&newmHandoff.lock)
+			osyield()
+		}
+	}
+	if raceenabled {
+		lock(&mFixupRace.lock)
+		mFixupRace.ctx = 0
+		unlock(&mFixupRace.lock)
+	}
+	startTheWorldGC()
+}
+
 // runSafePointFn runs the safe point function, if any, for this P.
 // This should be called like
 //
@@ -1816,6 +1957,7 @@ var newmHandoff struct {
 //go:nowritebarrierrec
 func newm(fn func(), _p_ *p, id int64) {
 	mp := allocm(_p_, fn, id)
+	mp.doesPark = (_p_ != nil)
 	mp.nextp.set(_p_)
 	mp.sigmask = initSigmask
 	if gp := getg(); gp != nil && gp.m != nil && (gp.m.lockedExt != 0 || gp.m.incgo) && GOOS != "plan9" {
@@ -1888,6 +2030,57 @@ func startTemplateThread() {
 	releasem(mp)
 }
 
+// mFixupRace is used to temporarily borrow the race context from the
+// coordinating m during a syscall_runtime_doAllThreadsSyscall and
+// loan it out to each of the m's of the runtime so they can execute a
+// mFixup.fn in that context.
+var mFixupRace struct {
+	lock mutex
+	ctx  uintptr
+}
+
+// mDoFixup runs any outstanding fixup function for the running m.
+// Returns true if a fixup was outstanding and actually executed.
+//
+//go:nosplit
+func mDoFixup() bool {
+	_g_ := getg()
+	lock(&_g_.m.mFixup.lock)
+	fn := _g_.m.mFixup.fn
+	if fn != nil {
+		if gcphase != _GCoff {
+			// We can't have a write barrier in this
+			// context since we may not have a P, but we
+			// clear fn to signal that we've executed the
+			// fixup. As long as fn is kept alive
+			// elsewhere, technically we should have no
+			// issues with the GC, but fn is likely
+			// generated in a different package altogether
+			// that may change independently. Just assert
+			// the GC is off so this lack of write barrier
+			// is more obviously safe.
+			throw("GC must be disabled to protect validity of fn value")
+		}
+		*(*uintptr)(unsafe.Pointer(&_g_.m.mFixup.fn)) = 0
+		if _g_.racectx != 0 || !raceenabled {
+			fn(false)
+		} else {
+			// temporarily acquire the context of the
+			// originator of the
+			// syscall_runtime_doAllThreadsSyscall and
+			// block others from using it for the duration
+			// of the fixup call.
+			lock(&mFixupRace.lock)
+			_g_.racectx = mFixupRace.ctx
+			fn(false)
+			_g_.racectx = 0
+			unlock(&mFixupRace.lock)
+		}
+	}
+	unlock(&_g_.m.mFixup.lock)
+	return fn != nil
+}
+
 // templateThread is a thread in a known-good state that exists solely
 // to start new threads in known-good states when the calling thread
 // may not be in a good state.
@@ -1924,6 +2117,7 @@ func templateThread() {
 		noteclear(&newmHandoff.wake)
 		unlock(&newmHandoff.lock)
 		notesleep(&newmHandoff.wake)
+		mDoFixup()
 	}
 }
 
@@ -1945,8 +2139,7 @@ func stopm() {
 	lock(&sched.lock)
 	mput(_g_.m)
 	unlock(&sched.lock)
-	notesleep(&_g_.m.park)
-	noteclear(&_g_.m.park)
+	mPark()
 	acquirep(_g_.m.nextp.ptr())
 	_g_.m.nextp = 0
 }
@@ -2106,8 +2299,7 @@ func stoplockedm() {
 	}
 	incidlelocked(1)
 	// Wait until another thread schedules lockedg again.
-	notesleep(&_g_.m.park)
-	noteclear(&_g_.m.park)
+	mPark()
 	status := readgstatus(_g_.m.lockedg.ptr())
 	if status&^_Gscan != _Grunnable {
 		print("runtime:stoplockedm: g is not Grunnable or Gscanrunnable\n")
@@ -4715,9 +4907,14 @@ func sysmon() {
 	checkdead()
 	unlock(&sched.lock)
 
+	// For syscall_runtime_doAllThreadsSyscall, sysmon is
+	// sufficiently up to participate in fixups.
+	atomic.Store(&sched.sysmonStarting, 0)
+
 	lasttrace := int64(0)
 	idle := 0 // how many cycles in succession we had not wokeup somebody
 	delay := uint32(0)
+
 	for {
 		if idle == 0 { // start with 20us sleep...
 			delay = 20
@@ -4728,6 +4925,7 @@ func sysmon() {
 			delay = 10 * 1000
 		}
 		usleep(delay)
+		mDoFixup()
 		now := nanotime()
 		next, _ := timeSleepUntil()
 		if debug.schedtrace <= 0 && (sched.gcwaiting != 0 || atomic.Load(&sched.npidle) == uint32(gomaxprocs)) {
@@ -4747,6 +4945,7 @@ func sysmon() {
 						osRelax(true)
 					}
 					notetsleep(&sched.sysmonnote, sleep)
+					mDoFixup()
 					if shouldRelax {
 						osRelax(false)
 					}
@@ -4795,6 +4994,7 @@ func sysmon() {
 				incidlelocked(1)
 			}
 		}
+		mDoFixup()
 		if next < now {
 			// There are timers that should have already run,
 			// perhaps because there is an unpreemptible P.
diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go
index 0758a35e01..21dd7b3949 100644
--- a/src/runtime/runtime2.go
+++ b/src/runtime/runtime2.go
@@ -528,6 +528,7 @@ type m struct {
 	ncgo          int32       // number of cgo calls currently in progress
 	cgoCallersUse uint32      // if non-zero, cgoCallers in use temporarily
 	cgoCallers    *cgoCallers // cgo traceback if crashing in cgo call
+	doesPark      bool        // non-P running threads: sysmon and newmHandoff never use .park
 	park          note
 	alllink       *m // on allm
 	schedlink     muintptr
@@ -544,6 +545,13 @@ type m struct {
 	syscalltick   uint32
 	freelink      *m // on sched.freem
 
+	// mFixup is used to synchronize OS related m state (credentials etc)
+	// use mutex to access.
+	mFixup struct {
+		lock mutex
+		fn   func(bool) bool
+	}
+
 	// these are here because they are too large to be on the stack
 	// of low-level NOSPLIT functions.
 	libcall   libcall
@@ -768,6 +776,10 @@ type schedt struct {
 	sysmonwait uint32
 	sysmonnote note
 
+	// While true, sysmon not ready for mFixup calls.
+	// Accessed atomically.
+	sysmonStarting uint32
+
 	// safepointFn should be called on each P at the next GC
 	// safepoint if p.runSafePointFn is set.
 	safePointFn   func(*p)
diff --git a/src/syscall/setuidgid_32_linux.go b/src/syscall/setuidgid_32_linux.go
index 1fe7120d1c..b0b7f61d22 100644
--- a/src/syscall/setuidgid_32_linux.go
+++ b/src/syscall/setuidgid_32_linux.go
@@ -12,4 +12,10 @@ const (
 
 	sys_SETGID = SYS_SETGID32
 	sys_SETUID = SYS_SETUID32
+
+	sys_SETREGID = SYS_SETREGID32
+	sys_SETREUID = SYS_SETREUID32
+
+	sys_SETRESGID = SYS_SETRESGID32
+	sys_SETRESUID = SYS_SETRESUID32
 )
diff --git a/src/syscall/setuidgid_linux.go b/src/syscall/setuidgid_linux.go
index 22fa334bfa..38c83c92f9 100644
--- a/src/syscall/setuidgid_linux.go
+++ b/src/syscall/setuidgid_linux.go
@@ -12,4 +12,10 @@ const (
 
 	sys_SETGID = SYS_SETGID
 	sys_SETUID = SYS_SETUID
+
+	sys_SETREGID = SYS_SETREGID
+	sys_SETREUID = SYS_SETREUID
+
+	sys_SETRESGID = SYS_SETRESGID
+	sys_SETRESUID = SYS_SETRESUID
 )
diff --git a/src/syscall/syscall_linux.go b/src/syscall/syscall_linux.go
index 07fe6a6c2b..54e5cfc2f2 100644
--- a/src/syscall/syscall_linux.go
+++ b/src/syscall/syscall_linux.go
@@ -271,16 +271,37 @@ func Getgroups() (gids []int, err error) {
 	return
 }
 
+var cgo_libc_setgroups unsafe.Pointer // non-nil if cgo linked.
+
 func Setgroups(gids []int) (err error) {
-	if len(gids) == 0 {
-		return setgroups(0, nil)
+	n := uintptr(len(gids))
+	if n == 0 {
+		if cgo_libc_setgroups == nil {
+			if _, _, e1 := AllThreadsSyscall(_SYS_setgroups, 0, 0, 0); e1 != 0 {
+				err = errnoErr(e1)
+			}
+			return
+		}
+		if ret := cgocaller(cgo_libc_setgroups, 0, 0); ret != 0 {
+			err = errnoErr(Errno(ret))
+		}
+		return
 	}
 
 	a := make([]_Gid_t, len(gids))
 	for i, v := range gids {
 		a[i] = _Gid_t(v)
 	}
-	return setgroups(len(a), &a[0])
+	if cgo_libc_setgroups == nil {
+		if _, _, e1 := AllThreadsSyscall(_SYS_setgroups, n, uintptr(unsafe.Pointer(&a[0])), 0); e1 != 0 {
+			err = errnoErr(e1)
+		}
+		return
+	}
+	if ret := cgocaller(cgo_libc_setgroups, n, uintptr(unsafe.Pointer(&a[0]))); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
 }
 
 type WaitStatus uint32
@@ -957,17 +978,223 @@ func Getpgrp() (pid int) {
 //sysnb	Setsid() (pid int, err error)
 //sysnb	Settimeofday(tv *Timeval) (err error)
 
-// issue 1435.
-// On linux Setuid and Setgid only affects the current thread, not the process.
-// This does not match what most callers expect so we must return an error
-// here rather than letting the caller think that the call succeeded.
+// allThreadsCaller holds the input and output state for performing a
+// allThreadsSyscall that needs to synchronize all OS thread state. Linux
+// generally does not always support this natively, so we have to
+// manipulate the runtime to fix things up.
+type allThreadsCaller struct {
+	// arguments
+	trap, a1, a2, a3, a4, a5, a6 uintptr
+
+	// return values (only set by 0th invocation)
+	r1, r2 uintptr
+
+	// err is the error code
+	err Errno
+}
+
+// doSyscall is a callback for executing a syscall on the current m
+// (OS thread).
+//go:nosplit
+//go:norace
+func (pc *allThreadsCaller) doSyscall(initial bool) bool {
+	r1, r2, err := RawSyscall(pc.trap, pc.a1, pc.a2, pc.a3)
+	if initial {
+		pc.r1 = r1
+		pc.r2 = r2
+		pc.err = err
+	} else if pc.r1 != r1 || pc.r2 != r2 || pc.err != err {
+		panic("AllThreadsSyscall results differ between threads; runtime corrupted")
+	}
+	return err == 0
+}
+
+// doSyscall6 is a callback for executing a syscall6 on the current m
+// (OS thread).
+//go:nosplit
+//go:norace
+func (pc *allThreadsCaller) doSyscall6(initial bool) bool {
+	r1, r2, err := RawSyscall6(pc.trap, pc.a1, pc.a2, pc.a3, pc.a4, pc.a5, pc.a6)
+	if initial {
+		pc.r1 = r1
+		pc.r2 = r2
+		pc.err = err
+	} else if pc.r1 != r1 || pc.r2 != r2 || pc.err != err {
+		panic("AllThreadsSyscall6 results differ between threads; runtime corrupted")
+	}
+	return err == 0
+}
+
+// Provided by runtime.syscall_runtime_doAllThreadsSyscall which
+// serializes the world and invokes the fn on each OS thread (what the
+// runtime refers to as m's). Once this function returns, all threads
+// are in sync.
+func runtime_doAllThreadsSyscall(fn func(bool) bool)
+
+// AllThreadsSyscall performs a syscall on each OS thread of the Go
+// runtime. It first invokes the syscall on one thread. Should that
+// invocation fail, it returns immediately with the error status.
+// Otherwise, it invokes the syscall on all of the remaining threads
+// in parallel. It will terminate the program if it observes any
+// invoked syscall's return value differs from that of the first
+// invocation.
+//
+// AllThreadsSyscall is intended for emulating simultaneous
+// process-wide state changes that require consistently modifying
+// per-thread state of the Go runtime.
+//
+// AllThreadsSyscall is unaware of any threads that are launched
+// explicitly by cgo linked code, so the function always returns
+// ENOTSUP in binaries that use cgo.
+//go:uintptrescapes
+func AllThreadsSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) {
+	if cgo_libc_setegid != nil {
+		return minus1, minus1, ENOTSUP
+	}
+	pc := &allThreadsCaller{
+		trap: trap,
+		a1:   a1,
+		a2:   a2,
+		a3:   a3,
+	}
+	runtime_doAllThreadsSyscall(pc.doSyscall)
+	r1 = pc.r1
+	r2 = pc.r2
+	err = pc.err
+	return
+}
 
-func Setuid(uid int) (err error) {
-	return EOPNOTSUPP
+// AllThreadsSyscall6 is like AllThreadsSyscall, but extended to six
+// arguments.
+//go:uintptrescapes
+func AllThreadsSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno) {
+	if cgo_libc_setegid != nil {
+		return minus1, minus1, ENOTSUP
+	}
+	pc := &allThreadsCaller{
+		trap: trap,
+		a1:   a1,
+		a2:   a2,
+		a3:   a3,
+		a4:   a4,
+		a5:   a5,
+		a6:   a6,
+	}
+	runtime_doAllThreadsSyscall(pc.doSyscall6)
+	r1 = pc.r1
+	r2 = pc.r2
+	err = pc.err
+	return
+}
+
+// linked by runtime.cgocall.go
+//go:uintptrescapes
+func cgocaller(unsafe.Pointer, ...uintptr) uintptr
+
+var cgo_libc_setegid unsafe.Pointer // non-nil if cgo linked.
+
+const minus1 = ^uintptr(0)
+
+func Setegid(egid int) (err error) {
+	if cgo_libc_setegid == nil {
+		if _, _, e1 := AllThreadsSyscall(SYS_SETRESGID, minus1, uintptr(egid), minus1); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setegid, uintptr(egid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_seteuid unsafe.Pointer // non-nil if cgo linked.
+
+func Seteuid(euid int) (err error) {
+	if cgo_libc_seteuid == nil {
+		if _, _, e1 := AllThreadsSyscall(SYS_SETRESUID, minus1, uintptr(euid), minus1); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_seteuid, uintptr(euid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
 }
 
+var cgo_libc_setgid unsafe.Pointer // non-nil if cgo linked.
+
 func Setgid(gid int) (err error) {
-	return EOPNOTSUPP
+	if cgo_libc_setgid == nil {
+		if _, _, e1 := AllThreadsSyscall(sys_SETGID, uintptr(gid), 0, 0); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setgid, uintptr(gid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_setregid unsafe.Pointer // non-nil if cgo linked.
+
+func Setregid(rgid, egid int) (err error) {
+	if cgo_libc_setregid == nil {
+		if _, _, e1 := AllThreadsSyscall(sys_SETREGID, uintptr(rgid), uintptr(egid), 0); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setregid, uintptr(rgid), uintptr(egid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_setresgid unsafe.Pointer // non-nil if cgo linked.
+
+func Setresgid(rgid, egid, sgid int) (err error) {
+	if cgo_libc_setresgid == nil {
+		if _, _, e1 := AllThreadsSyscall(sys_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid)); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setresgid, uintptr(rgid), uintptr(egid), uintptr(sgid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_setresuid unsafe.Pointer // non-nil if cgo linked.
+
+func Setresuid(ruid, euid, suid int) (err error) {
+	if cgo_libc_setresuid == nil {
+		if _, _, e1 := AllThreadsSyscall(sys_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid)); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setresuid, uintptr(ruid), uintptr(euid), uintptr(suid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_setreuid unsafe.Pointer // non-nil if cgo linked.
+
+func Setreuid(ruid, euid int) (err error) {
+	if cgo_libc_setreuid == nil {
+		if _, _, e1 := AllThreadsSyscall(sys_SETREUID, uintptr(ruid), uintptr(euid), 0); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setreuid, uintptr(ruid), uintptr(euid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_setuid unsafe.Pointer // non-nil if cgo linked.
+
+func Setuid(uid int) (err error) {
+	if cgo_libc_setuid == nil {
+		if _, _, e1 := AllThreadsSyscall(sys_SETUID, uintptr(uid), 0, 0); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setuid, uintptr(uid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
 }
 
 //sys	Setpriority(which int, who int, prio int) (err error)
diff --git a/src/syscall/syscall_linux_386.go b/src/syscall/syscall_linux_386.go
index 54baff5127..dd5f2735d8 100644
--- a/src/syscall/syscall_linux_386.go
+++ b/src/syscall/syscall_linux_386.go
@@ -64,16 +64,11 @@ func Pipe2(p []int, flags int) (err error) {
 //sys	sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) = SYS_SENDFILE64
 //sys	Setfsgid(gid int) (err error) = SYS_SETFSGID32
 //sys	Setfsuid(uid int) (err error) = SYS_SETFSUID32
-//sysnb	Setregid(rgid int, egid int) (err error) = SYS_SETREGID32
-//sysnb	Setresgid(rgid int, egid int, sgid int) (err error) = SYS_SETRESGID32
-//sysnb	Setresuid(ruid int, euid int, suid int) (err error) = SYS_SETRESUID32
-//sysnb	Setreuid(ruid int, euid int) (err error) = SYS_SETREUID32
 //sys	Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int, err error)
 //sys	SyncFileRange(fd int, off int64, n int64, flags int) (err error)
 //sys	Truncate(path string, length int64) (err error) = SYS_TRUNCATE64
 //sys	Ustat(dev int, ubuf *Ustat_t) (err error)
 //sysnb	getgroups(n int, list *_Gid_t) (nn int, err error) = SYS_GETGROUPS32
-//sysnb	setgroups(n int, list *_Gid_t) (err error) = SYS_SETGROUPS32
 //sys	Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err error) = SYS__NEWSELECT
 
 //sys	mmap2(addr uintptr, length uintptr, prot int, flags int, fd int, pageOffset uintptr) (xaddr uintptr, err error)
diff --git a/src/syscall/syscall_linux_amd64.go b/src/syscall/syscall_linux_amd64.go
index bf340d9996..5518f44a07 100644
--- a/src/syscall/syscall_linux_amd64.go
+++ b/src/syscall/syscall_linux_amd64.go
@@ -30,11 +30,7 @@ const _SYS_setgroups = SYS_SETGROUPS
 //sys	sendfile(outfd int, infd int, offset *int64, count int) (written int, err error)
 //sys	Setfsgid(gid int) (err error)
 //sys	Setfsuid(uid int) (err error)
-//sysnb	Setregid(rgid int, egid int) (err error)
-//sysnb	Setresgid(rgid int, egid int, sgid int) (err error)
-//sysnb	Setresuid(ruid int, euid int, suid int) (err error)
 //sysnb	Setrlimit(resource int, rlim *Rlimit) (err error)
-//sysnb	Setreuid(ruid int, euid int) (err error)
 //sys	Shutdown(fd int, how int) (err error)
 //sys	Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int64, err error)
 //sys	Statfs(path string, buf *Statfs_t) (err error)
@@ -47,7 +43,6 @@ const _SYS_setgroups = SYS_SETGROUPS
 //sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sys	fstatat(fd int, path string, stat *Stat_t, flags int) (err error) = SYS_NEWFSTATAT
 //sysnb	getgroups(n int, list *_Gid_t) (nn int, err error)
-//sysnb	setgroups(n int, list *_Gid_t) (err error)
 //sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
 //sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
 //sysnb	socket(domain int, typ int, proto int) (fd int, err error)
diff --git a/src/syscall/syscall_linux_arm.go b/src/syscall/syscall_linux_arm.go
index c4c403a400..61133a59fb 100644
--- a/src/syscall/syscall_linux_arm.go
+++ b/src/syscall/syscall_linux_arm.go
@@ -63,7 +63,6 @@ func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
 //sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sysnb	getgroups(n int, list *_Gid_t) (nn int, err error) = SYS_GETGROUPS32
-//sysnb	setgroups(n int, list *_Gid_t) (err error) = SYS_SETGROUPS32
 //sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
 //sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
 //sysnb	socket(domain int, typ int, proto int) (fd int, err error)
@@ -94,10 +93,6 @@ func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
 //sys	Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err error) = SYS__NEWSELECT
 //sys	Setfsgid(gid int) (err error) = SYS_SETFSGID32
 //sys	Setfsuid(uid int) (err error) = SYS_SETFSUID32
-//sysnb	Setregid(rgid int, egid int) (err error) = SYS_SETREGID32
-//sysnb	Setresgid(rgid int, egid int, sgid int) (err error) = SYS_SETRESGID32
-//sysnb	Setresuid(ruid int, euid int, suid int) (err error) = SYS_SETRESUID32
-//sysnb	Setreuid(ruid int, euid int) (err error) = SYS_SETREUID32
 //sys	Shutdown(fd int, how int) (err error)
 //sys	Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int, err error)
 //sys	Ustat(dev int, ubuf *Ustat_t) (err error)
diff --git a/src/syscall/syscall_linux_arm64.go b/src/syscall/syscall_linux_arm64.go
index 61014b264a..16382102c8 100644
--- a/src/syscall/syscall_linux_arm64.go
+++ b/src/syscall/syscall_linux_arm64.go
@@ -35,9 +35,6 @@ func EpollCreate(size int) (fd int, err error) {
 //sys	sendfile(outfd int, infd int, offset *int64, count int) (written int, err error)
 //sys	Setfsgid(gid int) (err error)
 //sys	Setfsuid(uid int) (err error)
-//sysnb	Setregid(rgid int, egid int) (err error)
-//sysnb	Setresgid(rgid int, egid int, sgid int) (err error)
-//sysnb	Setresuid(ruid int, euid int, suid int) (err error)
 //sysnb	setrlimit(resource int, rlim *Rlimit) (err error)
 //sysnb	Setreuid(ruid int, euid int) (err error)
 //sys	Shutdown(fd int, how int) (err error)
@@ -63,7 +60,6 @@ func Lstat(path string, stat *Stat_t) (err error) {
 //sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sysnb	getgroups(n int, list *_Gid_t) (nn int, err error)
-//sysnb	setgroups(n int, list *_Gid_t) (err error)
 //sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
 //sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
 //sysnb	socket(domain int, typ int, proto int) (fd int, err error)
diff --git a/src/syscall/syscall_linux_mips64x.go b/src/syscall/syscall_linux_mips64x.go
index e3683def67..4986baa319 100644
--- a/src/syscall/syscall_linux_mips64x.go
+++ b/src/syscall/syscall_linux_mips64x.go
@@ -31,11 +31,7 @@ const _SYS_setgroups = SYS_SETGROUPS
 //sys	sendfile(outfd int, infd int, offset *int64, count int) (written int, err error)
 //sys	Setfsgid(gid int) (err error)
 //sys	Setfsuid(uid int) (err error)
-//sysnb	Setregid(rgid int, egid int) (err error)
-//sysnb	Setresgid(rgid int, egid int, sgid int) (err error)
-//sysnb	Setresuid(ruid int, euid int, suid int) (err error)
 //sysnb	Setrlimit(resource int, rlim *Rlimit) (err error)
-//sysnb	Setreuid(ruid int, euid int) (err error)
 //sys	Shutdown(fd int, how int) (err error)
 //sys	Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int64, err error)
 //sys	Statfs(path string, buf *Statfs_t) (err error)
@@ -47,7 +43,6 @@ const _SYS_setgroups = SYS_SETGROUPS
 //sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sysnb	getgroups(n int, list *_Gid_t) (nn int, err error)
-//sysnb	setgroups(n int, list *_Gid_t) (err error)
 //sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
 //sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
 //sysnb	socket(domain int, typ int, proto int) (fd int, err error)
diff --git a/src/syscall/syscall_linux_mipsx.go b/src/syscall/syscall_linux_mipsx.go
index cbe2f0233f..5126b0e43c 100644
--- a/src/syscall/syscall_linux_mipsx.go
+++ b/src/syscall/syscall_linux_mipsx.go
@@ -32,11 +32,6 @@ func Syscall9(trap, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr,
 //sys	sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) = SYS_SENDFILE64
 //sys	Setfsgid(gid int) (err error)
 //sys	Setfsuid(uid int) (err error)
-//sysnb	Setregid(rgid int, egid int) (err error)
-//sysnb	Setresgid(rgid int, egid int, sgid int) (err error)
-//sysnb	Setresuid(ruid int, euid int, suid int) (err error)
-
-//sysnb	Setreuid(ruid int, euid int) (err error)
 //sys	Shutdown(fd int, how int) (err error)
 //sys	Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int, err error)
 
@@ -48,7 +43,6 @@ func Syscall9(trap, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr,
 //sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sysnb	getgroups(n int, list *_Gid_t) (nn int, err error)
-//sysnb	setgroups(n int, list *_Gid_t) (err error)
 //sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
 //sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
 //sysnb	socket(domain int, typ int, proto int) (fd int, err error)
diff --git a/src/syscall/syscall_linux_ppc64x.go b/src/syscall/syscall_linux_ppc64x.go
index ba52e5a3ac..bb2d904b5f 100644
--- a/src/syscall/syscall_linux_ppc64x.go
+++ b/src/syscall/syscall_linux_ppc64x.go
@@ -37,11 +37,7 @@ const _SYS_setgroups = SYS_SETGROUPS
 //sys	sendfile(outfd int, infd int, offset *int64, count int) (written int, err error)
 //sys	Setfsgid(gid int) (err error)
 //sys	Setfsuid(uid int) (err error)
-//sysnb	Setregid(rgid int, egid int) (err error)
-//sysnb	Setresgid(rgid int, egid int, sgid int) (err error)
-//sysnb	Setresuid(ruid int, euid int, suid int) (err error)
 //sysnb	Setrlimit(resource int, rlim *Rlimit) (err error)
-//sysnb	Setreuid(ruid int, euid int) (err error)
 //sys	Shutdown(fd int, how int) (err error)
 //sys	Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int64, err error)
 //sys	Stat(path string, stat *Stat_t) (err error)
@@ -53,7 +49,6 @@ const _SYS_setgroups = SYS_SETGROUPS
 //sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sysnb	getgroups(n int, list *_Gid_t) (nn int, err error)
-//sysnb	setgroups(n int, list *_Gid_t) (err error)
 //sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
 //sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
 //sysnb	socket(domain int, typ int, proto int) (fd int, err error)
diff --git a/src/syscall/syscall_linux_riscv64.go b/src/syscall/syscall_linux_riscv64.go
index 088e23439f..aa1014f8ae 100644
--- a/src/syscall/syscall_linux_riscv64.go
+++ b/src/syscall/syscall_linux_riscv64.go
@@ -35,11 +35,7 @@ func EpollCreate(size int) (fd int, err error) {
 //sys	sendfile(outfd int, infd int, offset *int64, count int) (written int, err error)
 //sys	Setfsgid(gid int) (err error)
 //sys	Setfsuid(uid int) (err error)
-//sysnb	Setregid(rgid int, egid int) (err error)
-//sysnb	Setresgid(rgid int, egid int, sgid int) (err error)
-//sysnb	Setresuid(ruid int, euid int, suid int) (err error)
 //sysnb	Setrlimit(resource int, rlim *Rlimit) (err error)
-//sysnb	Setreuid(ruid int, euid int) (err error)
 //sys	Shutdown(fd int, how int) (err error)
 //sys	Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int64, err error)
 
@@ -67,7 +63,6 @@ func Lstat(path string, stat *Stat_t) (err error) {
 //sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 //sysnb	getgroups(n int, list *_Gid_t) (nn int, err error)
-//sysnb	setgroups(n int, list *_Gid_t) (err error)
 //sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
 //sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
 //sysnb	socket(domain int, typ int, proto int) (fd int, err error)
diff --git a/src/syscall/syscall_linux_s390x.go b/src/syscall/syscall_linux_s390x.go
index 80cb1ccc19..dc97d5c65a 100644
--- a/src/syscall/syscall_linux_s390x.go
+++ b/src/syscall/syscall_linux_s390x.go
@@ -33,11 +33,7 @@ const _SYS_setgroups = SYS_SETGROUPS
 //sys	sendfile(outfd int, infd int, offset *int64, count int) (written int, err error)
 //sys	Setfsgid(gid int) (err error)
 //sys	Setfsuid(uid int) (err error)
-//sysnb	Setregid(rgid int, egid int) (err error)
-//sysnb	Setresgid(rgid int, egid int, sgid int) (err error)
-//sysnb	Setresuid(ruid int, euid int, suid int) (err error)
 //sysnb	Setrlimit(resource int, rlim *Rlimit) (err error)
-//sysnb	Setreuid(ruid int, euid int) (err error)
 //sys	Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int64, err error)
 //sys	Stat(path string, stat *Stat_t) (err error)
 //sys	Statfs(path string, buf *Statfs_t) (err error)
@@ -45,7 +41,6 @@ const _SYS_setgroups = SYS_SETGROUPS
 //sys	Truncate(path string, length int64) (err error)
 //sys	Ustat(dev int, ubuf *Ustat_t) (err error)
 //sysnb	getgroups(n int, list *_Gid_t) (nn int, err error)
-//sysnb	setgroups(n int, list *_Gid_t) (err error)
 
 //sys	futimesat(dirfd int, path string, times *[2]Timeval) (err error)
 //sysnb	Gettimeofday(tv *Timeval) (err error)
diff --git a/src/syscall/syscall_linux_test.go b/src/syscall/syscall_linux_test.go
index 93a4d236d8..d196534c64 100644
--- a/src/syscall/syscall_linux_test.go
+++ b/src/syscall/syscall_linux_test.go
@@ -399,3 +399,229 @@ func syscallNoError() {
 	fmt.Println(uintptr(euid1), "/", int(e), "/", uintptr(euid2))
 	os.Exit(0)
 }
+
+// reference uapi/linux/prctl.h
+const (
+	PR_GET_KEEPCAPS uintptr = 7
+	PR_SET_KEEPCAPS         = 8
+)
+
+// TestAllThreadsSyscall tests that the go runtime can perform
+// syscalls that execute on all OSThreads - with which to support
+// POSIX semantics for security state changes.
+func TestAllThreadsSyscall(t *testing.T) {
+	if _, _, err := syscall.AllThreadsSyscall(syscall.SYS_PRCTL, PR_SET_KEEPCAPS, 0, 0); err == syscall.ENOTSUP {
+		t.Skip("AllThreadsSyscall disabled with cgo")
+	}
+
+	fns := []struct {
+		label string
+		fn    func(uintptr) error
+	}{
+		{
+			label: "prctl<3-args>",
+			fn: func(v uintptr) error {
+				_, _, e := syscall.AllThreadsSyscall(syscall.SYS_PRCTL, PR_SET_KEEPCAPS, v, 0)
+				if e != 0 {
+					return e
+				}
+				return nil
+			},
+		},
+		{
+			label: "prctl<6-args>",
+			fn: func(v uintptr) error {
+				_, _, e := syscall.AllThreadsSyscall6(syscall.SYS_PRCTL, PR_SET_KEEPCAPS, v, 0, 0, 0, 0)
+				if e != 0 {
+					return e
+				}
+				return nil
+			},
+		},
+	}
+
+	waiter := func(q <-chan uintptr, r chan<- uintptr, once bool) {
+		for x := range q {
+			runtime.LockOSThread()
+			v, _, e := syscall.Syscall(syscall.SYS_PRCTL, PR_GET_KEEPCAPS, 0, 0)
+			if e != 0 {
+				t.Errorf("tid=%d prctl(PR_GET_KEEPCAPS) failed: %v", syscall.Gettid(), e)
+			} else if x != v {
+				t.Errorf("tid=%d prctl(PR_GET_KEEPCAPS) mismatch: got=%d want=%d", syscall.Gettid(), v, x)
+			}
+			r <- v
+			if once {
+				break
+			}
+			runtime.UnlockOSThread()
+		}
+	}
+
+	// launches per fns member.
+	const launches = 11
+	question := make(chan uintptr)
+	response := make(chan uintptr)
+	defer close(question)
+
+	routines := 0
+	for i, v := range fns {
+		for j := 0; j < launches; j++ {
+			// Add another goroutine - the closest thing
+			// we can do to encourage more OS thread
+			// creation - while the test is running.  The
+			// actual thread creation may or may not be
+			// needed, based on the number of available
+			// unlocked OS threads at the time waiter
+			// calls runtime.LockOSThread(), but the goal
+			// of doing this every time through the loop
+			// is to race thread creation with v.fn(want)
+			// being executed. Via the once boolean we
+			// also encourage one in 5 waiters to return
+			// locked after participating in only one
+			// question response sequence. This allows the
+			// test to race thread destruction too.
+			once := routines%5 == 4
+			go waiter(question, response, once)
+
+			// Keep a count of how many goroutines are
+			// going to participate in the
+			// question/response test. This will count up
+			// towards 2*launches minus the count of
+			// routines that have been invoked with
+			// once=true.
+			routines++
+
+			// Decide what value we want to set the
+			// process-shared KEEPCAPS. Note, there is
+			// an explicit repeat of 0 when we change the
+			// variant of the syscall being used.
+			want := uintptr(j & 1)
+
+			// Invoke the AllThreadsSyscall* variant.
+			if err := v.fn(want); err != nil {
+				t.Errorf("[%d,%d] %s(PR_SET_KEEPCAPS, %d, ...): %v", i, j, v.label, j&1, err)
+			}
+
+			// At this point, we want all launched Go
+			// routines to confirm that they see the
+			// wanted value for KEEPCAPS.
+			for k := 0; k < routines; k++ {
+				question <- want
+			}
+
+			// At this point, we should have a large
+			// number of locked OS threads all wanting to
+			// reply.
+			for k := 0; k < routines; k++ {
+				if got := <-response; got != want {
+					t.Errorf("[%d,%d,%d] waiter result got=%d, want=%d", i, j, k, got, want)
+				}
+			}
+
+			// Provide an explicit opportunity for this Go
+			// routine to change Ms.
+			runtime.Gosched()
+
+			if once {
+				// One waiter routine will have exited.
+				routines--
+			}
+
+			// Whatever M we are now running on, confirm
+			// we see the wanted value too.
+			if v, _, e := syscall.Syscall(syscall.SYS_PRCTL, PR_GET_KEEPCAPS, 0, 0); e != 0 {
+				t.Errorf("[%d,%d] prctl(PR_GET_KEEPCAPS) failed: %v", i, j, e)
+			} else if v != want {
+				t.Errorf("[%d,%d] prctl(PR_GET_KEEPCAPS) gave wrong value: got=%v, want=1", i, j, v)
+			}
+		}
+	}
+}
+
+// compareStatus is used to confirm the contents of the thread
+// specific status files match expectations.
+func compareStatus(filter, expect string) error {
+	expected := filter + "\t" + expect
+	pid := syscall.Getpid()
+	fs, err := ioutil.ReadDir(fmt.Sprintf("/proc/%d/task", pid))
+	if err != nil {
+		return fmt.Errorf("unable to find %d tasks: %v", pid, err)
+	}
+	for _, f := range fs {
+		tf := fmt.Sprintf("/proc/%s/status", f.Name())
+		d, err := ioutil.ReadFile(tf)
+		if err != nil {
+			return fmt.Errorf("unable to read %q: %v", tf, err)
+		}
+		lines := strings.Split(string(d), "\n")
+		for _, line := range lines {
+			if strings.HasPrefix(line, filter) {
+				if line != expected {
+					return fmt.Errorf("%s %s (bad)\n", tf, line)
+				}
+				break
+			}
+		}
+	}
+	return nil
+}
+
+// TestSetuidEtc performs tests on all of the wrapped system calls
+// that mirror to the 9 glibc syscalls with POSIX semantics. The test
+// here is considered authoritative and should compile and run
+// CGO_ENABLED=0 or 1. Note, there is an extended copy of this same
+// test in ../../misc/cgo/test/issue1435.go which requires
+// CGO_ENABLED=1 and launches pthreads from C that run concurrently
+// with the Go code of the test - and the test validates that these
+// pthreads are also kept in sync with the security state changed with
+// the syscalls. Care should be taken to mirror any enhancements to
+// this test here in that file too.
+func TestSetuidEtc(t *testing.T) {
+	if syscall.Getuid() != 0 {
+		t.Skip("skipping root only test")
+	}
+	vs := []struct {
+		call           string
+		fn             func() error
+		filter, expect string
+	}{
+		{call: "Setegid(1)", fn: func() error { return syscall.Setegid(1) }, filter: "Gid:", expect: "0\t1\t0\t1"},
+		{call: "Setegid(0)", fn: func() error { return syscall.Setegid(0) }, filter: "Gid:", expect: "0\t0\t0\t0"},
+
+		{call: "Seteuid(1)", fn: func() error { return syscall.Seteuid(1) }, filter: "Uid:", expect: "0\t1\t0\t1"},
+		{call: "Setuid(0)", fn: func() error { return syscall.Setuid(0) }, filter: "Uid:", expect: "0\t0\t0\t0"},
+
+		{call: "Setgid(1)", fn: func() error { return syscall.Setgid(1) }, filter: "Gid:", expect: "1\t1\t1\t1"},
+		{call: "Setgid(0)", fn: func() error { return syscall.Setgid(0) }, filter: "Gid:", expect: "0\t0\t0\t0"},
+
+		{call: "Setgroups([]int{0,1,2,3})", fn: func() error { return syscall.Setgroups([]int{0, 1, 2, 3}) }, filter: "Groups:", expect: "0 1 2 3 "},
+		{call: "Setgroups(nil)", fn: func() error { return syscall.Setgroups(nil) }, filter: "Groups:", expect: " "},
+		{call: "Setgroups([]int{0})", fn: func() error { return syscall.Setgroups([]int{0}) }, filter: "Groups:", expect: "0 "},
+
+		{call: "Setregid(101,0)", fn: func() error { return syscall.Setregid(101, 0) }, filter: "Gid:", expect: "101\t0\t0\t0"},
+		{call: "Setregid(0,102)", fn: func() error { return syscall.Setregid(0, 102) }, filter: "Gid:", expect: "0\t102\t102\t102"},
+		{call: "Setregid(0,0)", fn: func() error { return syscall.Setregid(0, 0) }, filter: "Gid:", expect: "0\t0\t0\t0"},
+
+		{call: "Setreuid(1,0)", fn: func() error { return syscall.Setreuid(1, 0) }, filter: "Uid:", expect: "1\t0\t0\t0"},
+		{call: "Setreuid(0,2)", fn: func() error { return syscall.Setreuid(0, 2) }, filter: "Uid:", expect: "0\t2\t2\t2"},
+		{call: "Setreuid(0,0)", fn: func() error { return syscall.Setreuid(0, 0) }, filter: "Uid:", expect: "0\t0\t0\t0"},
+
+		{call: "Setresgid(101,0,102)", fn: func() error { return syscall.Setresgid(101, 0, 102) }, filter: "Gid:", expect: "101\t0\t102\t0"},
+		{call: "Setresgid(0,102,101)", fn: func() error { return syscall.Setresgid(0, 102, 101) }, filter: "Gid:", expect: "0\t102\t101\t102"},
+		{call: "Setresgid(0,0,0)", fn: func() error { return syscall.Setresgid(0, 0, 0) }, filter: "Gid:", expect: "0\t0\t0\t0"},
+
+		{call: "Setresuid(1,0,2)", fn: func() error { return syscall.Setresuid(1, 0, 2) }, filter: "Uid:", expect: "1\t0\t2\t0"},
+		{call: "Setresuid(0,2,1)", fn: func() error { return syscall.Setresuid(0, 2, 1) }, filter: "Uid:", expect: "0\t2\t1\t2"},
+		{call: "Setresuid(0,0,0)", fn: func() error { return syscall.Setresuid(0, 0, 0) }, filter: "Uid:", expect: "0\t0\t0\t0"},
+	}
+
+	for i, v := range vs {
+		if err := v.fn(); err != nil {
+			t.Errorf("[%d] %q failed: %v", i, v.call, err)
+			continue
+		}
+		if err := compareStatus(v.filter, v.expect); err != nil {
+			t.Errorf("[%d] %q comparison: %v", i, v.call, err)
+		}
+	}
+}
diff --git a/src/syscall/zsyscall_linux_386.go b/src/syscall/zsyscall_linux_386.go
index cdf0bfb86e..5a749ff3f3 100644
--- a/src/syscall/zsyscall_linux_386.go
+++ b/src/syscall/zsyscall_linux_386.go
@@ -1291,46 +1291,6 @@ func Setfsuid(uid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID32, uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID32, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID32, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID32, uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int, err error) {
 	r0, _, e1 := Syscall6(SYS_SPLICE, uintptr(rfd), uintptr(unsafe.Pointer(roff)), uintptr(wfd), uintptr(unsafe.Pointer(woff)), uintptr(len), uintptr(flags))
 	n = int(r0)
@@ -1388,16 +1348,6 @@ func getgroups(n int, list *_Gid_t) (nn int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func setgroups(n int, list *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS32, uintptr(n), uintptr(unsafe.Pointer(list)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err error) {
 	r0, _, e1 := Syscall6(SYS__NEWSELECT, uintptr(nfd), uintptr(unsafe.Pointer(r)), uintptr(unsafe.Pointer(w)), uintptr(unsafe.Pointer(e)), uintptr(unsafe.Pointer(timeout)), 0)
 	n = int(r0)
diff --git a/src/syscall/zsyscall_linux_amd64.go b/src/syscall/zsyscall_linux_amd64.go
index a7d55e6894..34b624c1d4 100644
--- a/src/syscall/zsyscall_linux_amd64.go
+++ b/src/syscall/zsyscall_linux_amd64.go
@@ -1308,36 +1308,6 @@ func Setfsuid(uid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID, uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(resource int, rlim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(resource), uintptr(unsafe.Pointer(rlim)), 0)
 	if e1 != 0 {
@@ -1348,16 +1318,6 @@ func Setrlimit(resource int, rlim *Rlimit) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID, uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Shutdown(fd int, how int) (err error) {
 	_, _, e1 := Syscall(SYS_SHUTDOWN, uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
@@ -1497,16 +1457,6 @@ func getgroups(n int, list *_Gid_t) (nn int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func setgroups(n int, list *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS, uintptr(n), uintptr(unsafe.Pointer(list)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
 	_, _, e1 := Syscall6(SYS_GETSOCKOPT, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
diff --git a/src/syscall/zsyscall_linux_arm.go b/src/syscall/zsyscall_linux_arm.go
index 1a9a21a4f3..4d133766f7 100644
--- a/src/syscall/zsyscall_linux_arm.go
+++ b/src/syscall/zsyscall_linux_arm.go
@@ -1120,16 +1120,6 @@ func getgroups(n int, list *_Gid_t) (nn int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func setgroups(n int, list *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS32, uintptr(n), uintptr(unsafe.Pointer(list)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
 	_, _, e1 := Syscall6(SYS_GETSOCKOPT, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
@@ -1427,46 +1417,6 @@ func Setfsuid(uid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID32, uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID32, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID32, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID32, uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Shutdown(fd int, how int) (err error) {
 	_, _, e1 := Syscall(SYS_SHUTDOWN, uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
diff --git a/src/syscall/zsyscall_linux_arm64.go b/src/syscall/zsyscall_linux_arm64.go
index f20f05e8d5..e7f7b7e3f8 100644
--- a/src/syscall/zsyscall_linux_arm64.go
+++ b/src/syscall/zsyscall_linux_arm64.go
@@ -1282,36 +1282,6 @@ func Setfsuid(uid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID, uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func setrlimit(resource int, rlim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(resource), uintptr(unsafe.Pointer(rlim)), 0)
 	if e1 != 0 {
@@ -1322,16 +1292,6 @@ func setrlimit(resource int, rlim *Rlimit) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID, uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Shutdown(fd int, how int) (err error) {
 	_, _, e1 := Syscall(SYS_SHUTDOWN, uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
@@ -1446,16 +1406,6 @@ func getgroups(n int, list *_Gid_t) (nn int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func setgroups(n int, list *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS, uintptr(n), uintptr(unsafe.Pointer(list)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
 	_, _, e1 := Syscall6(SYS_GETSOCKOPT, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
diff --git a/src/syscall/zsyscall_linux_mips.go b/src/syscall/zsyscall_linux_mips.go
index 7945b55642..a8522dc571 100644
--- a/src/syscall/zsyscall_linux_mips.go
+++ b/src/syscall/zsyscall_linux_mips.go
@@ -1266,46 +1266,6 @@ func Setfsuid(uid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID, uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID, uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Shutdown(fd int, how int) (err error) {
 	_, _, e1 := Syscall(SYS_SHUTDOWN, uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
@@ -1415,16 +1375,6 @@ func getgroups(n int, list *_Gid_t) (nn int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func setgroups(n int, list *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS, uintptr(n), uintptr(unsafe.Pointer(list)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
 	_, _, e1 := Syscall6(SYS_GETSOCKOPT, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
diff --git a/src/syscall/zsyscall_linux_mips64.go b/src/syscall/zsyscall_linux_mips64.go
index c0aad6439f..1219fcc6cb 100644
--- a/src/syscall/zsyscall_linux_mips64.go
+++ b/src/syscall/zsyscall_linux_mips64.go
@@ -1297,36 +1297,6 @@ func Setfsuid(uid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID, uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(resource int, rlim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(resource), uintptr(unsafe.Pointer(rlim)), 0)
 	if e1 != 0 {
@@ -1337,16 +1307,6 @@ func Setrlimit(resource int, rlim *Rlimit) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID, uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Shutdown(fd int, how int) (err error) {
 	_, _, e1 := Syscall(SYS_SHUTDOWN, uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
@@ -1471,16 +1431,6 @@ func getgroups(n int, list *_Gid_t) (nn int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func setgroups(n int, list *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS, uintptr(n), uintptr(unsafe.Pointer(list)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
 	_, _, e1 := Syscall6(SYS_GETSOCKOPT, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
diff --git a/src/syscall/zsyscall_linux_mips64le.go b/src/syscall/zsyscall_linux_mips64le.go
index 271684137d..c3737bf3cf 100644
--- a/src/syscall/zsyscall_linux_mips64le.go
+++ b/src/syscall/zsyscall_linux_mips64le.go
@@ -1297,36 +1297,6 @@ func Setfsuid(uid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID, uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(resource int, rlim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(resource), uintptr(unsafe.Pointer(rlim)), 0)
 	if e1 != 0 {
@@ -1337,16 +1307,6 @@ func Setrlimit(resource int, rlim *Rlimit) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID, uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Shutdown(fd int, how int) (err error) {
 	_, _, e1 := Syscall(SYS_SHUTDOWN, uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
@@ -1471,16 +1431,6 @@ func getgroups(n int, list *_Gid_t) (nn int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func setgroups(n int, list *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS, uintptr(n), uintptr(unsafe.Pointer(list)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
 	_, _, e1 := Syscall6(SYS_GETSOCKOPT, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
diff --git a/src/syscall/zsyscall_linux_mipsle.go b/src/syscall/zsyscall_linux_mipsle.go
index f0ee48f9be..5006f4a409 100644
--- a/src/syscall/zsyscall_linux_mipsle.go
+++ b/src/syscall/zsyscall_linux_mipsle.go
@@ -1266,46 +1266,6 @@ func Setfsuid(uid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID, uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID, uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Shutdown(fd int, how int) (err error) {
 	_, _, e1 := Syscall(SYS_SHUTDOWN, uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
@@ -1415,16 +1375,6 @@ func getgroups(n int, list *_Gid_t) (nn int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func setgroups(n int, list *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS, uintptr(n), uintptr(unsafe.Pointer(list)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
 	_, _, e1 := Syscall6(SYS_GETSOCKOPT, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
diff --git a/src/syscall/zsyscall_linux_ppc64.go b/src/syscall/zsyscall_linux_ppc64.go
index 7bdf981dcd..323be988be 100644
--- a/src/syscall/zsyscall_linux_ppc64.go
+++ b/src/syscall/zsyscall_linux_ppc64.go
@@ -1370,36 +1370,6 @@ func Setfsuid(uid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID, uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(resource int, rlim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(resource), uintptr(unsafe.Pointer(rlim)), 0)
 	if e1 != 0 {
@@ -1410,16 +1380,6 @@ func Setrlimit(resource int, rlim *Rlimit) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID, uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Shutdown(fd int, how int) (err error) {
 	_, _, e1 := Syscall(SYS_SHUTDOWN, uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
@@ -1549,16 +1509,6 @@ func getgroups(n int, list *_Gid_t) (nn int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func setgroups(n int, list *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS, uintptr(n), uintptr(unsafe.Pointer(list)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
 	_, _, e1 := Syscall6(SYS_GETSOCKOPT, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
diff --git a/src/syscall/zsyscall_linux_ppc64le.go b/src/syscall/zsyscall_linux_ppc64le.go
index c45eebf4ad..99aea6b559 100644
--- a/src/syscall/zsyscall_linux_ppc64le.go
+++ b/src/syscall/zsyscall_linux_ppc64le.go
@@ -1370,36 +1370,6 @@ func Setfsuid(uid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID, uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(resource int, rlim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(resource), uintptr(unsafe.Pointer(rlim)), 0)
 	if e1 != 0 {
@@ -1410,16 +1380,6 @@ func Setrlimit(resource int, rlim *Rlimit) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID, uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Shutdown(fd int, how int) (err error) {
 	_, _, e1 := Syscall(SYS_SHUTDOWN, uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
@@ -1549,16 +1509,6 @@ func getgroups(n int, list *_Gid_t) (nn int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func setgroups(n int, list *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS, uintptr(n), uintptr(unsafe.Pointer(list)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
 	_, _, e1 := Syscall6(SYS_GETSOCKOPT, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
diff --git a/src/syscall/zsyscall_linux_riscv64.go b/src/syscall/zsyscall_linux_riscv64.go
index 7bdb8046d1..afa8945944 100644
--- a/src/syscall/zsyscall_linux_riscv64.go
+++ b/src/syscall/zsyscall_linux_riscv64.go
@@ -1282,36 +1282,6 @@ func Setfsuid(uid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID, uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(resource int, rlim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(resource), uintptr(unsafe.Pointer(rlim)), 0)
 	if e1 != 0 {
@@ -1322,16 +1292,6 @@ func Setrlimit(resource int, rlim *Rlimit) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID, uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Shutdown(fd int, how int) (err error) {
 	_, _, e1 := Syscall(SYS_SHUTDOWN, uintptr(fd), uintptr(how), 0)
 	if e1 != 0 {
@@ -1446,16 +1406,6 @@ func getgroups(n int, list *_Gid_t) (nn int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func setgroups(n int, list *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS, uintptr(n), uintptr(unsafe.Pointer(list)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) {
 	_, _, e1 := Syscall6(SYS_GETSOCKOPT, uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen)), 0)
 	if e1 != 0 {
diff --git a/src/syscall/zsyscall_linux_s390x.go b/src/syscall/zsyscall_linux_s390x.go
index 9ada8dc534..5717206f28 100644
--- a/src/syscall/zsyscall_linux_s390x.go
+++ b/src/syscall/zsyscall_linux_s390x.go
@@ -1340,36 +1340,6 @@ func Setfsuid(uid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setregid(rgid int, egid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREGID, uintptr(rgid), uintptr(egid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(resource int, rlim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(resource), uintptr(unsafe.Pointer(rlim)), 0)
 	if e1 != 0 {
@@ -1380,16 +1350,6 @@ func Setrlimit(resource int, rlim *Rlimit) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setreuid(ruid int, euid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETREUID, uintptr(ruid), uintptr(euid), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int64, err error) {
 	r0, _, e1 := Syscall6(SYS_SPLICE, uintptr(rfd), uintptr(unsafe.Pointer(roff)), uintptr(wfd), uintptr(unsafe.Pointer(woff)), uintptr(len), uintptr(flags))
 	n = int64(r0)
@@ -1477,16 +1437,6 @@ func getgroups(n int, list *_Gid_t) (nn int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func setgroups(n int, list *_Gid_t) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETGROUPS, uintptr(n), uintptr(unsafe.Pointer(list)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func futimesat(dirfd int, path string, times *[2]Timeval) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(path)