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Diffstat (limited to 'src/pkg/syscall/exec_linux.go')
-rw-r--r--src/pkg/syscall/exec_linux.go262
1 files changed, 0 insertions, 262 deletions
diff --git a/src/pkg/syscall/exec_linux.go b/src/pkg/syscall/exec_linux.go
deleted file mode 100644
index f27950f73..000000000
--- a/src/pkg/syscall/exec_linux.go
+++ /dev/null
@@ -1,262 +0,0 @@
-// Copyright 2011 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
-
-package syscall
-
-import (
- "unsafe"
-)
-
-type SysProcAttr struct {
- Chroot string // Chroot.
- Credential *Credential // Credential.
- Ptrace bool // Enable tracing.
- Setsid bool // Create session.
- Setpgid bool // Set process group ID to new pid (SYSV setpgrp)
- Setctty bool // Set controlling terminal to fd Ctty (only meaningful if Setsid is set)
- Noctty bool // Detach fd 0 from controlling terminal
- Ctty int // Controlling TTY fd (Linux only)
- Pdeathsig Signal // Signal that the process will get when its parent dies (Linux only)
- Cloneflags uintptr // Flags for clone calls (Linux only)
-}
-
-// Implemented in runtime package.
-func runtime_BeforeFork()
-func runtime_AfterFork()
-
-// Fork, dup fd onto 0..len(fd), and exec(argv0, argvv, envv) in child.
-// If a dup or exec fails, write the errno error to pipe.
-// (Pipe is close-on-exec so if exec succeeds, it will be closed.)
-// In the child, this function must not acquire any locks, because
-// they might have been locked at the time of the fork. This means
-// no rescheduling, no malloc calls, and no new stack segments.
-// For the same reason compiler does not race instrument it.
-// The calls to RawSyscall are okay because they are assembly
-// functions that do not grow the stack.
-func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr *ProcAttr, sys *SysProcAttr, pipe int) (pid int, err Errno) {
- // Declare all variables at top in case any
- // declarations require heap allocation (e.g., err1).
- var (
- r1 uintptr
- err1 Errno
- nextfd int
- i int
- )
-
- // Guard against side effects of shuffling fds below.
- // Make sure that nextfd is beyond any currently open files so
- // that we can't run the risk of overwriting any of them.
- fd := make([]int, len(attr.Files))
- nextfd = len(attr.Files)
- for i, ufd := range attr.Files {
- if nextfd < int(ufd) {
- nextfd = int(ufd)
- }
- fd[i] = int(ufd)
- }
- nextfd++
-
- // About to call fork.
- // No more allocation or calls of non-assembly functions.
- runtime_BeforeFork()
- r1, _, err1 = RawSyscall6(SYS_CLONE, uintptr(SIGCHLD)|sys.Cloneflags, 0, 0, 0, 0, 0)
- if err1 != 0 {
- runtime_AfterFork()
- return 0, err1
- }
-
- if r1 != 0 {
- // parent; return PID
- runtime_AfterFork()
- return int(r1), 0
- }
-
- // Fork succeeded, now in child.
-
- // Parent death signal
- if sys.Pdeathsig != 0 {
- _, _, err1 = RawSyscall6(SYS_PRCTL, PR_SET_PDEATHSIG, uintptr(sys.Pdeathsig), 0, 0, 0, 0)
- if err1 != 0 {
- goto childerror
- }
-
- // Signal self if parent is already dead. This might cause a
- // duplicate signal in rare cases, but it won't matter when
- // using SIGKILL.
- r1, _, _ = RawSyscall(SYS_GETPPID, 0, 0, 0)
- if r1 == 1 {
- pid, _, _ := RawSyscall(SYS_GETPID, 0, 0, 0)
- _, _, err1 := RawSyscall(SYS_KILL, pid, uintptr(sys.Pdeathsig), 0)
- if err1 != 0 {
- goto childerror
- }
- }
- }
-
- // Enable tracing if requested.
- if sys.Ptrace {
- _, _, err1 = RawSyscall(SYS_PTRACE, uintptr(PTRACE_TRACEME), 0, 0)
- if err1 != 0 {
- goto childerror
- }
- }
-
- // Session ID
- if sys.Setsid {
- _, _, err1 = RawSyscall(SYS_SETSID, 0, 0, 0)
- if err1 != 0 {
- goto childerror
- }
- }
-
- // Set process group
- if sys.Setpgid {
- _, _, err1 = RawSyscall(SYS_SETPGID, 0, 0, 0)
- if err1 != 0 {
- goto childerror
- }
- }
-
- // Chroot
- if chroot != nil {
- _, _, err1 = RawSyscall(SYS_CHROOT, uintptr(unsafe.Pointer(chroot)), 0, 0)
- if err1 != 0 {
- goto childerror
- }
- }
-
- // User and groups
- if cred := sys.Credential; cred != nil {
- ngroups := uintptr(len(cred.Groups))
- var groups unsafe.Pointer
- if ngroups > 0 {
- groups = unsafe.Pointer(&cred.Groups[0])
- }
- _, _, err1 = RawSyscall(SYS_SETGROUPS, ngroups, uintptr(groups), 0)
- if err1 != 0 {
- goto childerror
- }
- _, _, err1 = RawSyscall(SYS_SETGID, uintptr(cred.Gid), 0, 0)
- if err1 != 0 {
- goto childerror
- }
- _, _, err1 = RawSyscall(SYS_SETUID, uintptr(cred.Uid), 0, 0)
- if err1 != 0 {
- goto childerror
- }
- }
-
- // Chdir
- if dir != nil {
- _, _, err1 = RawSyscall(SYS_CHDIR, uintptr(unsafe.Pointer(dir)), 0, 0)
- if err1 != 0 {
- goto childerror
- }
- }
-
- // Pass 1: look for fd[i] < i and move those up above len(fd)
- // so that pass 2 won't stomp on an fd it needs later.
- if pipe < nextfd {
- _, _, err1 = RawSyscall(SYS_DUP2, uintptr(pipe), uintptr(nextfd), 0)
- if err1 != 0 {
- goto childerror
- }
- RawSyscall(SYS_FCNTL, uintptr(nextfd), F_SETFD, FD_CLOEXEC)
- pipe = nextfd
- nextfd++
- }
- for i = 0; i < len(fd); i++ {
- if fd[i] >= 0 && fd[i] < int(i) {
- _, _, err1 = RawSyscall(SYS_DUP2, uintptr(fd[i]), uintptr(nextfd), 0)
- if err1 != 0 {
- goto childerror
- }
- RawSyscall(SYS_FCNTL, uintptr(nextfd), F_SETFD, FD_CLOEXEC)
- fd[i] = nextfd
- nextfd++
- if nextfd == pipe { // don't stomp on pipe
- nextfd++
- }
- }
- }
-
- // Pass 2: dup fd[i] down onto i.
- for i = 0; i < len(fd); i++ {
- if fd[i] == -1 {
- RawSyscall(SYS_CLOSE, uintptr(i), 0, 0)
- continue
- }
- if fd[i] == int(i) {
- // dup2(i, i) won't clear close-on-exec flag on Linux,
- // probably not elsewhere either.
- _, _, err1 = RawSyscall(SYS_FCNTL, uintptr(fd[i]), F_SETFD, 0)
- if err1 != 0 {
- goto childerror
- }
- continue
- }
- // The new fd is created NOT close-on-exec,
- // which is exactly what we want.
- _, _, err1 = RawSyscall(SYS_DUP2, uintptr(fd[i]), uintptr(i), 0)
- if err1 != 0 {
- goto childerror
- }
- }
-
- // By convention, we don't close-on-exec the fds we are
- // started with, so if len(fd) < 3, close 0, 1, 2 as needed.
- // Programs that know they inherit fds >= 3 will need
- // to set them close-on-exec.
- for i = len(fd); i < 3; i++ {
- RawSyscall(SYS_CLOSE, uintptr(i), 0, 0)
- }
-
- // Detach fd 0 from tty
- if sys.Noctty {
- _, _, err1 = RawSyscall(SYS_IOCTL, 0, uintptr(TIOCNOTTY), 0)
- if err1 != 0 {
- goto childerror
- }
- }
-
- // Set the controlling TTY to Ctty
- if sys.Setctty && sys.Ctty >= 0 {
- _, _, err1 = RawSyscall(SYS_IOCTL, uintptr(sys.Ctty), uintptr(TIOCSCTTY), 0)
- if err1 != 0 {
- goto childerror
- }
- }
-
- // Time to exec.
- _, _, err1 = RawSyscall(SYS_EXECVE,
- uintptr(unsafe.Pointer(argv0)),
- uintptr(unsafe.Pointer(&argv[0])),
- uintptr(unsafe.Pointer(&envv[0])))
-
-childerror:
- // send error code on pipe
- RawSyscall(SYS_WRITE, uintptr(pipe), uintptr(unsafe.Pointer(&err1)), unsafe.Sizeof(err1))
- for {
- RawSyscall(SYS_EXIT, 253, 0, 0)
- }
-}
-
-// Try to open a pipe with O_CLOEXEC set on both file descriptors.
-func forkExecPipe(p []int) (err error) {
- err = Pipe2(p, O_CLOEXEC)
- // pipe2 was added in 2.6.27 and our minimum requirement is 2.6.23, so it
- // might not be implemented.
- if err == ENOSYS {
- if err = Pipe(p); err != nil {
- return
- }
- if _, err = fcntl(p[0], F_SETFD, FD_CLOEXEC); err != nil {
- return
- }
- _, err = fcntl(p[1], F_SETFD, FD_CLOEXEC)
- }
- return
-}