syscall_aix.go

     1  // Copyright 2018 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  package runtime
     6  
     7  import "unsafe"
     8  
     9  // This file handles some syscalls from the syscall package
    10  // Especially, syscalls use during forkAndExecInChild which must not split the stack
    11  
    12  //go:cgo_import_dynamic libc_chdir chdir "libc.a/shr_64.o"
    13  //go:cgo_import_dynamic libc_chroot chroot "libc.a/shr_64.o"
    14  //go:cgo_import_dynamic libc_dup2 dup2 "libc.a/shr_64.o"
    15  //go:cgo_import_dynamic libc_execve execve "libc.a/shr_64.o"
    16  //go:cgo_import_dynamic libc_fcntl fcntl "libc.a/shr_64.o"
    17  //go:cgo_import_dynamic libc_fork fork "libc.a/shr_64.o"
    18  //go:cgo_import_dynamic libc_ioctl ioctl "libc.a/shr_64.o"
    19  //go:cgo_import_dynamic libc_setgid setgid "libc.a/shr_64.o"
    20  //go:cgo_import_dynamic libc_setgroups setgroups "libc.a/shr_64.o"
    21  //go:cgo_import_dynamic libc_setrlimit setrlimit "libc.a/shr_64.o"
    22  //go:cgo_import_dynamic libc_setsid setsid "libc.a/shr_64.o"
    23  //go:cgo_import_dynamic libc_setuid setuid "libc.a/shr_64.o"
    24  //go:cgo_import_dynamic libc_setpgid setpgid "libc.a/shr_64.o"
    25  
    26  //go:linkname libc_chdir libc_chdir
    27  //go:linkname libc_chroot libc_chroot
    28  //go:linkname libc_dup2 libc_dup2
    29  //go:linkname libc_execve libc_execve
    30  //go:linkname libc_fcntl libc_fcntl
    31  //go:linkname libc_fork libc_fork
    32  //go:linkname libc_ioctl libc_ioctl
    33  //go:linkname libc_setgid libc_setgid
    34  //go:linkname libc_setgroups libc_setgroups
    35  //go:linkname libc_setrlimit libc_setrlimit
    36  //go:linkname libc_setsid libc_setsid
    37  //go:linkname libc_setuid libc_setuid
    38  //go:linkname libc_setpgid libc_setpgid
    39  
    40  var (
    41  	libc_chdir,
    42  	libc_chroot,
    43  	libc_dup2,
    44  	libc_execve,
    45  	libc_fcntl,
    46  	libc_fork,
    47  	libc_ioctl,
    48  	libc_setgid,
    49  	libc_setgroups,
    50  	libc_setrlimit,
    51  	libc_setsid,
    52  	libc_setuid,
    53  	libc_setpgid libFunc
    54  )
    55  
    56  // In syscall_syscall6 and syscall_rawsyscall6, r2 is always 0
    57  // as it's never used on AIX
    58  // TODO: remove r2 from zsyscall_aix_$GOARCH.go
    59  
    60  // Syscall is needed because some packages (like net) need it too.
    61  // The best way is to return EINVAL and let Golang handles its failure
    62  // If the syscall can't fail, this function can redirect it to a real syscall.
    63  //
    64  // This is exported via linkname to assembly in the syscall package.
    65  //
    66  //go:nosplit
    67  //go:linkname syscall_Syscall
    68  func syscall_Syscall(fn, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
    69  	return 0, 0, _EINVAL
    70  }
    71  
    72  // This is syscall.RawSyscall, it exists to satisfy some build dependency,
    73  // but it doesn't work.
    74  //
    75  // This is exported via linkname to assembly in the syscall package.
    76  //
    77  //go:linkname syscall_RawSyscall
    78  func syscall_RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
    79  	panic("RawSyscall not available on AIX")
    80  }
    81  
    82  // This is exported via linkname to assembly in the syscall package.
    83  //
    84  //go:nosplit
    85  //go:cgo_unsafe_args
    86  //go:linkname syscall_syscall6
    87  func syscall_syscall6(fn, nargs, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
    88  	c := libcall{
    89  		fn:   fn,
    90  		n:    nargs,
    91  		args: uintptr(unsafe.Pointer(&a1)),
    92  	}
    93  
    94  	entersyscallblock()
    95  	asmcgocall(unsafe.Pointer(&asmsyscall6), unsafe.Pointer(&c))
    96  	exitsyscall()
    97  	return c.r1, 0, c.err
    98  }
    99  
   100  // This is exported via linkname to assembly in the syscall package.
   101  //
   102  //go:nosplit
   103  //go:cgo_unsafe_args
   104  //go:linkname syscall_rawSyscall6
   105  func syscall_rawSyscall6(fn, nargs, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
   106  	c := libcall{
   107  		fn:   fn,
   108  		n:    nargs,
   109  		args: uintptr(unsafe.Pointer(&a1)),
   110  	}
   111  
   112  	asmcgocall(unsafe.Pointer(&asmsyscall6), unsafe.Pointer(&c))
   113  
   114  	return c.r1, 0, c.err
   115  }
   116  
   117  //go:linkname syscall_chdir syscall.chdir
   118  //go:nosplit
   119  func syscall_chdir(path uintptr) (err uintptr) {
   120  	_, err = syscall1(&libc_chdir, path)
   121  	return
   122  }
   123  
   124  //go:linkname syscall_chroot1 syscall.chroot1
   125  //go:nosplit
   126  func syscall_chroot1(path uintptr) (err uintptr) {
   127  	_, err = syscall1(&libc_chroot, path)
   128  	return
   129  }
   130  
   131  // like close, but must not split stack, for fork.
   132  //
   133  //go:linkname syscall_closeFD syscall.closeFD
   134  //go:nosplit
   135  func syscall_closeFD(fd int32) int32 {
   136  	_, err := syscall1(&libc_close, uintptr(fd))
   137  	return int32(err)
   138  }
   139  
   140  //go:linkname syscall_dup2child syscall.dup2child
   141  //go:nosplit
   142  func syscall_dup2child(old, new uintptr) (val, err uintptr) {
   143  	val, err = syscall2(&libc_dup2, old, new)
   144  	return
   145  }
   146  
   147  //go:linkname syscall_execve syscall.execve
   148  //go:nosplit
   149  func syscall_execve(path, argv, envp uintptr) (err uintptr) {
   150  	_, err = syscall3(&libc_execve, path, argv, envp)
   151  	return
   152  }
   153  
   154  // like exit, but must not split stack, for fork.
   155  //
   156  //go:linkname syscall_exit syscall.exit
   157  //go:nosplit
   158  func syscall_exit(code uintptr) {
   159  	syscall1(&libc_exit, code)
   160  }
   161  
   162  //go:linkname syscall_fcntl1 syscall.fcntl1
   163  //go:nosplit
   164  func syscall_fcntl1(fd, cmd, arg uintptr) (val, err uintptr) {
   165  	val, err = syscall3(&libc_fcntl, fd, cmd, arg)
   166  	return
   167  }
   168  
   169  //go:linkname syscall_forkx syscall.forkx
   170  //go:nosplit
   171  func syscall_forkx(flags uintptr) (pid uintptr, err uintptr) {
   172  	pid, err = syscall1(&libc_fork, flags)
   173  	return
   174  }
   175  
   176  //go:linkname syscall_getpid syscall.getpid
   177  //go:nosplit
   178  func syscall_getpid() (pid, err uintptr) {
   179  	pid, err = syscall0(&libc_getpid)
   180  	return
   181  }
   182  
   183  //go:linkname syscall_ioctl syscall.ioctl
   184  //go:nosplit
   185  func syscall_ioctl(fd, req, arg uintptr) (err uintptr) {
   186  	_, err = syscall3(&libc_ioctl, fd, req, arg)
   187  	return
   188  }
   189  
   190  //go:linkname syscall_setgid syscall.setgid
   191  //go:nosplit
   192  func syscall_setgid(gid uintptr) (err uintptr) {
   193  	_, err = syscall1(&libc_setgid, gid)
   194  	return
   195  }
   196  
   197  //go:linkname syscall_setgroups1 syscall.setgroups1
   198  //go:nosplit
   199  func syscall_setgroups1(ngid, gid uintptr) (err uintptr) {
   200  	_, err = syscall2(&libc_setgroups, ngid, gid)
   201  	return
   202  }
   203  
   204  //go:linkname syscall_setrlimit1 syscall.setrlimit1
   205  //go:nosplit
   206  func syscall_setrlimit1(which uintptr, lim unsafe.Pointer) (err uintptr) {
   207  	_, err = syscall2(&libc_setrlimit, which, uintptr(lim))
   208  	return
   209  }
   210  
   211  //go:linkname syscall_setsid syscall.setsid
   212  //go:nosplit
   213  func syscall_setsid() (pid, err uintptr) {
   214  	pid, err = syscall0(&libc_setsid)
   215  	return
   216  }
   217  
   218  //go:linkname syscall_setuid syscall.setuid
   219  //go:nosplit
   220  func syscall_setuid(uid uintptr) (err uintptr) {
   221  	_, err = syscall1(&libc_setuid, uid)
   222  	return
   223  }
   224  
   225  //go:linkname syscall_setpgid syscall.setpgid
   226  //go:nosplit
   227  func syscall_setpgid(pid, pgid uintptr) (err uintptr) {
   228  	_, err = syscall2(&libc_setpgid, pid, pgid)
   229  	return
   230  }
   231  
   232  //go:linkname syscall_write1 syscall.write1
   233  //go:nosplit
   234  func syscall_write1(fd, buf, nbyte uintptr) (n, err uintptr) {
   235  	n, err = syscall3(&libc_write, fd, buf, nbyte)
   236  	return
   237  }
   238
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