linux_syscall.c

Documentation: runtime/cgo

     1// Copyright 2019 The Go Authors. All rights reserved.
     2// Use of this source code is governed by a BSD-style
     3// license that can be found in the LICENSE file.
     4
     5//go:build linux
     6
     7#ifndef _GNU_SOURCE // setres[ug]id() API.
     8#define _GNU_SOURCE
     9#endif
    10
    11#include <grp.h>
    12#include <sys/types.h>
    13#include <unistd.h>
    14#include <errno.h>
    15#include "libcgo.h"
    16
    17/*
    18 * Assumed POSIX compliant libc system call wrappers. For linux, the
    19 * glibc/nptl/setxid mechanism ensures that POSIX semantics are
    20 * honored for all pthreads (by default), and this in turn with cgo
    21 * ensures that all Go threads launched with cgo are kept in sync for
    22 * these function calls.
    23 */
    24
    25// argset_t matches runtime/cgocall.go:argset.
    26typedef struct {
    27	uintptr_t* args;
    28	uintptr_t retval;
    29} argset_t;
    30
    31// libc backed posix-compliant syscalls.
    32
    33#define SET_RETVAL(fn) \
    34  uintptr_t ret = (uintptr_t) fn ; \
    35  if (ret == (uintptr_t) -1) {	   \
    36    x->retval = (uintptr_t) errno; \
    37  } else                           \
    38    x->retval = ret
    39
    40void
    41_cgo_libc_setegid(argset_t* x) {
    42	SET_RETVAL(setegid((gid_t) x->args[0]));
    43}
    44
    45void
    46_cgo_libc_seteuid(argset_t* x) {
    47	SET_RETVAL(seteuid((uid_t) x->args[0]));
    48}
    49
    50void
    51_cgo_libc_setgid(argset_t* x) {
    52	SET_RETVAL(setgid((gid_t) x->args[0]));
    53}
    54
    55void
    56_cgo_libc_setgroups(argset_t* x) {
    57	SET_RETVAL(setgroups((size_t) x->args[0], (const gid_t *) x->args[1]));
    58}
    59
    60void
    61_cgo_libc_setregid(argset_t* x) {
    62	SET_RETVAL(setregid((gid_t) x->args[0], (gid_t) x->args[1]));
    63}
    64
    65void
    66_cgo_libc_setresgid(argset_t* x) {
    67	SET_RETVAL(setresgid((gid_t) x->args[0], (gid_t) x->args[1],
    68			     (gid_t) x->args[2]));
    69}
    70
    71void
    72_cgo_libc_setresuid(argset_t* x) {
    73	SET_RETVAL(setresuid((uid_t) x->args[0], (uid_t) x->args[1],
    74			     (uid_t) x->args[2]));
    75}
    76
    77void
    78_cgo_libc_setreuid(argset_t* x) {
    79	SET_RETVAL(setreuid((uid_t) x->args[0], (uid_t) x->args[1]));
    80}
    81
    82void
    83_cgo_libc_setuid(argset_t* x) {
    84	SET_RETVAL(setuid((uid_t) x->args[0]));
    85}
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