diff options
Diffstat (limited to 'libgo/go/syscall/exec_linux.go')
| -rw-r--r-- | libgo/go/syscall/exec_linux.go | 76 |
1 files changed, 45 insertions, 31 deletions
diff --git a/libgo/go/syscall/exec_linux.go b/libgo/go/syscall/exec_linux.go index 6987bc1f4e..8d6467a872 100644 --- a/libgo/go/syscall/exec_linux.go +++ b/libgo/go/syscall/exec_linux.go @@ -7,7 +7,6 @@ package syscall import ( - "runtime" "unsafe" ) @@ -23,20 +22,21 @@ type SysProcIDMap struct { } type SysProcAttr struct { - Chroot string // Chroot. - Credential *Credential // Credential. - Ptrace bool // Enable tracing. - Setsid bool // Create session. - Setpgid bool // Set process group ID to Pgid, or, if Pgid == 0, to new pid. - 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 - Foreground bool // Place child's process group in foreground. (Implies Setpgid. Uses Ctty as fd of controlling TTY) - Pgid int // Child's process group ID if Setpgid. - Pdeathsig Signal // Signal that the process will get when its parent dies (Linux only) - Cloneflags uintptr // Flags for clone calls (Linux only) - UidMappings []SysProcIDMap // User ID mappings for user namespaces. - GidMappings []SysProcIDMap // Group ID mappings for user namespaces. + Chroot string // Chroot. + Credential *Credential // Credential. + Ptrace bool // Enable tracing. + Setsid bool // Create session. + Setpgid bool // Set process group ID to Pgid, or, if Pgid == 0, to new pid. + 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 + Foreground bool // Place child's process group in foreground. (Implies Setpgid. Uses Ctty as fd of controlling TTY) + Pgid int // Child's process group ID if Setpgid. + Pdeathsig Signal // Signal that the process will get when its parent dies (Linux only) + Cloneflags uintptr // Flags for clone calls (Linux only) + Unshareflags uintptr // Flags for unshare calls (Linux only) + UidMappings []SysProcIDMap // User ID mappings for user namespaces. + GidMappings []SysProcIDMap // Group ID mappings for user namespaces. // GidMappingsEnableSetgroups enabling setgroups syscall. // If false, then setgroups syscall will be disabled for the child process. // This parameter is no-op if GidMappings == nil. Otherwise for unprivileged @@ -48,11 +48,14 @@ type SysProcAttr struct { func runtime_BeforeFork() func runtime_AfterFork() +// Implemented in clone_linux.c +func rawClone(flags _C_ulong, child_stack *byte, ptid *Pid_t, ctid *Pid_t, regs unsafe.Pointer) _C_long + // 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 +// 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 @@ -63,6 +66,7 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr // declarations require heap allocation (e.g., err1). var ( r1 uintptr + r2 _C_long err1 Errno err2 Errno nextfd int @@ -97,20 +101,16 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr // About to call fork. // No more allocation or calls of non-assembly functions. runtime_BeforeFork() - if runtime.GOARCH == "s390x" || runtime.GOARCH == "s390" { - r1, _, err1 = RawSyscall6(SYS_CLONE, 0, uintptr(SIGCHLD)|sys.Cloneflags, 0, 0, 0, 0) - } else { - r1, _, err1 = RawSyscall6(SYS_CLONE, uintptr(SIGCHLD)|sys.Cloneflags, 0, 0, 0, 0, 0) - } - if err1 != 0 { + r2 = rawClone(_C_ulong(uintptr(SIGCHLD)|sys.Cloneflags), nil, nil, nil, unsafe.Pointer(nil)) + if r2 < 0 { runtime_AfterFork() - return 0, err1 + return 0, GetErrno() } - if r1 != 0 { + if r2 != 0 { // parent; return PID runtime_AfterFork() - pid = int(r1) + pid = int(r2) if sys.UidMappings != nil || sys.GidMappings != nil { Close(p[0]) @@ -192,21 +192,35 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr } } + // Unshare + if sys.Unshareflags != 0 { + _, _, err1 = RawSyscall(SYS_UNSHARE, sys.Unshareflags, 0, 0) + if err1 != 0 { + goto childerror + } + } + // User and groups if cred := sys.Credential; cred != nil { ngroups := len(cred.Groups) + var groups unsafe.Pointer if ngroups > 0 { - groups := unsafe.Pointer(&cred.Groups[0]) + groups = unsafe.Pointer(&cred.Groups[0]) + } + // Don't call setgroups in case of user namespace, gid mappings + // and disabled setgroups, because otherwise unprivileged user namespace + // will fail with any non-empty SysProcAttr.Credential. + if !(sys.GidMappings != nil && !sys.GidMappingsEnableSetgroups && ngroups == 0) { err1 = raw_setgroups(ngroups, groups) if err1 != 0 { goto childerror } } - _, _, err1 = RawSyscall(SYS_SETGID, uintptr(cred.Gid), 0, 0) + _, _, err1 = RawSyscall(sys_SETGID, uintptr(cred.Gid), 0, 0) if err1 != 0 { goto childerror } - _, _, err1 = RawSyscall(SYS_SETUID, uintptr(cred.Uid), 0, 0) + _, _, err1 = RawSyscall(sys_SETUID, uintptr(cred.Uid), 0, 0) if err1 != 0 { goto childerror } @@ -253,6 +267,9 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr } for i = 0; i < len(fd); i++ { if fd[i] >= 0 && fd[i] < int(i) { + if nextfd == pipe { // don't stomp on pipe + nextfd++ + } err1 = raw_dup2(fd[i], nextfd) if err1 != 0 { goto childerror @@ -260,9 +277,6 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr raw_fcntl(nextfd, F_SETFD, FD_CLOEXEC) fd[i] = nextfd nextfd++ - if nextfd == pipe { // don't stomp on pipe - nextfd++ - } } } |