Automated rollback of changelist 261387276

PiperOrigin-RevId: 266491264

1 files changed, 0 insertions, 179 deletions

diff --git a/pkg/sentry/kernel/thread_group.go b/pkg/sentry/kernel/thread_group.go
index 0eef24bfb..2a97e3e8e 100644
--- a/pkg/sentry/kernel/thread_group.go
+++ b/pkg/sentry/kernel/thread_group.go
@@ -19,13 +19,10 @@ import (
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
-	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
-	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
 	"gvisor.dev/gvisor/pkg/sentry/limits"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
-	"gvisor.dev/gvisor/pkg/syserror"
 )
 
 // A ThreadGroup is a logical grouping of tasks that has widespread
@@ -248,12 +245,6 @@ type ThreadGroup struct {
 	//
 	// mounts is immutable.
 	mounts *fs.MountNamespace
-
-	// tty is the thread group's controlling terminal. If nil, there is no
-	// controlling terminal.
-	//
-	// tty is protected by the signal mutex.
-	tty *TTY
 }
 
 // newThreadGroup returns a new, empty thread group in PID namespace ns. The
@@ -333,176 +324,6 @@ func (tg *ThreadGroup) forEachChildThreadGroupLocked(fn func(*ThreadGroup)) {
 	}
 }
 
-// SetControllingTTY sets tty as the controlling terminal of tg.
-func (tg *ThreadGroup) SetControllingTTY(tty *TTY, arg int32) error {
-	tty.mu.Lock()
-	defer tty.mu.Unlock()
-
-	// We might be asked to set the controlling terminal of multiple
-	// processes, so we lock both the TaskSet and SignalHandlers.
-	tg.pidns.owner.mu.Lock()
-	defer tg.pidns.owner.mu.Unlock()
-	tg.signalHandlers.mu.Lock()
-	defer tg.signalHandlers.mu.Unlock()
-
-	// "The calling process must be a session leader and not have a
-	// controlling terminal already." - tty_ioctl(4)
-	if tg.processGroup.session.leader != tg || tg.tty != nil {
-		return syserror.EINVAL
-	}
-
-	// "If this terminal is already the controlling terminal of a different
-	// session group, then the ioctl fails with EPERM, unless the caller
-	// has the CAP_SYS_ADMIN capability and arg equals 1, in which case the
-	// terminal is stolen, and all processes that had it as controlling
-	// terminal lose it." - tty_ioctl(4)
-	if tty.tg != nil && tg.processGroup.session != tty.tg.processGroup.session {
-		if !auth.CredentialsFromContext(tg.leader).HasCapability(linux.CAP_SYS_ADMIN) || arg != 1 {
-			return syserror.EPERM
-		}
-		// Steal the TTY away. Unlike TIOCNOTTY, don't send signals.
-		for othertg := range tg.pidns.owner.Root.tgids {
-			// This won't deadlock by locking tg.signalHandlers
-			// because at this point:
-			// - We only lock signalHandlers if it's in the same
-			//   session as the tty's controlling thread group.
-			// - We know that the calling thread group is not in
-			//   the same session as the tty's controlling thread
-			//   group.
-			if othertg.processGroup.session == tty.tg.processGroup.session {
-				othertg.signalHandlers.mu.Lock()
-				othertg.tty = nil
-				othertg.signalHandlers.mu.Unlock()
-			}
-		}
-	}
-
-	// Set the controlling terminal and foreground process group.
-	tg.tty = tty
-	tg.processGroup.session.foreground = tg.processGroup
-	// Set this as the controlling process of the terminal.
-	tty.tg = tg
-
-	return nil
-}
-
-// ReleaseControllingTTY gives up tty as the controlling tty of tg.
-func (tg *ThreadGroup) ReleaseControllingTTY(tty *TTY) error {
-	tty.mu.Lock()
-	defer tty.mu.Unlock()
-
-	// We might be asked to set the controlling terminal of multiple
-	// processes, so we lock both the TaskSet and SignalHandlers.
-	tg.pidns.owner.mu.RLock()
-	defer tg.pidns.owner.mu.RUnlock()
-
-	// Just below, we may re-lock signalHandlers in order to send signals.
-	// Thus we can't defer Unlock here.
-	tg.signalHandlers.mu.Lock()
-
-	if tg.tty == nil || tg.tty != tty {
-		tg.signalHandlers.mu.Unlock()
-		return syserror.ENOTTY
-	}
-
-	// "If the process was session leader, then send SIGHUP and SIGCONT to
-	// the foreground process group and all processes in the current
-	// session lose their controlling terminal." - tty_ioctl(4)
-	// Remove tty as the controlling tty for each process in the session,
-	// then send them SIGHUP and SIGCONT.
-
-	// If we're not the session leader, we don't have to do much.
-	if tty.tg != tg {
-		tg.tty = nil
-		tg.signalHandlers.mu.Unlock()
-		return nil
-	}
-
-	tg.signalHandlers.mu.Unlock()
-
-	// We're the session leader. SIGHUP and SIGCONT the foreground process
-	// group and remove all controlling terminals in the session.
-	var lastErr error
-	for othertg := range tg.pidns.owner.Root.tgids {
-		if othertg.processGroup.session == tg.processGroup.session {
-			othertg.signalHandlers.mu.Lock()
-			othertg.tty = nil
-			if othertg.processGroup == tg.processGroup.session.foreground {
-				if err := othertg.leader.sendSignalLocked(&arch.SignalInfo{Signo: int32(linux.SIGHUP)}, true /* group */); err != nil {
-					lastErr = err
-				}
-				if err := othertg.leader.sendSignalLocked(&arch.SignalInfo{Signo: int32(linux.SIGCONT)}, true /* group */); err != nil {
-					lastErr = err
-				}
-			}
-			othertg.signalHandlers.mu.Unlock()
-		}
-	}
-
-	return lastErr
-}
-
-// ForegroundProcessGroup returns the process group ID of the foreground
-// process group.
-func (tg *ThreadGroup) ForegroundProcessGroup(tty *TTY) (int32, error) {
-	tty.mu.Lock()
-	defer tty.mu.Unlock()
-
-	tg.pidns.owner.mu.Lock()
-	defer tg.pidns.owner.mu.Unlock()
-	tg.signalHandlers.mu.Lock()
-	defer tg.signalHandlers.mu.Unlock()
-
-	// "When fd does not refer to the controlling terminal of the calling
-	// process, -1 is returned" - tcgetpgrp(3)
-	if tg.tty != tty {
-		return -1, syserror.ENOTTY
-	}
-
-	return int32(tg.processGroup.session.foreground.id), nil
-}
-
-// SetForegroundProcessGroup sets the foreground process group of tty to pgid.
-func (tg *ThreadGroup) SetForegroundProcessGroup(tty *TTY, pgid ProcessGroupID) (int32, error) {
-	tty.mu.Lock()
-	defer tty.mu.Unlock()
-
-	tg.pidns.owner.mu.Lock()
-	defer tg.pidns.owner.mu.Unlock()
-	tg.signalHandlers.mu.Lock()
-	defer tg.signalHandlers.mu.Unlock()
-
-	// TODO(b/129283598): "If tcsetpgrp() is called by a member of a
-	// background process group in its session, and the calling process is
-	// not blocking or ignoring SIGTTOU, a SIGTTOU signal is sent to all
-	// members of this background process group."
-
-	// tty must be the controlling terminal.
-	if tg.tty != tty {
-		return -1, syserror.ENOTTY
-	}
-
-	// pgid must be positive.
-	if pgid < 0 {
-		return -1, syserror.EINVAL
-	}
-
-	// pg must not be empty. Empty process groups are removed from their
-	// pid namespaces.
-	pg, ok := tg.pidns.processGroups[pgid]
-	if !ok {
-		return -1, syserror.ESRCH
-	}
-
-	// pg must be part of this process's session.
-	if tg.processGroup.session != pg.session {
-		return -1, syserror.EPERM
-	}
-
-	tg.processGroup.session.foreground.id = pgid
-	return 0, nil
-}
-
 // itimerRealListener implements ktime.Listener for ITIMER_REAL expirations.
 //
 // +stateify savable