Merge pull request #1 from google/master

catch up

1 files changed, 19 insertions, 8 deletions

diff --git a/pkg/sentry/kernel/task_signals.go b/pkg/sentry/kernel/task_signals.go
index 39cd1340d..79766cafe 100644
--- a/pkg/sentry/kernel/task_signals.go
+++ b/pkg/sentry/kernel/task_signals.go
@@ -26,8 +26,8 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	ucspb "gvisor.dev/gvisor/pkg/sentry/kernel/uncaught_signal_go_proto"
-	"gvisor.dev/gvisor/pkg/sentry/usermem"
 	"gvisor.dev/gvisor/pkg/syserror"
+	"gvisor.dev/gvisor/pkg/usermem"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
 
@@ -174,7 +174,7 @@ func (t *Task) deliverSignal(info *arch.SignalInfo, act arch.SignalAct) taskRunS
 					fallthrough
 				case (sre == ERESTARTSYS && !act.IsRestart()):
 					t.Debugf("Not restarting syscall %d after errno %d: interrupted by signal %d", t.Arch().SyscallNo(), sre, info.Signo)
-					t.Arch().SetReturn(uintptr(-t.ExtractErrno(syserror.EINTR, -1)))
+					t.Arch().SetReturn(uintptr(-ExtractErrno(syserror.EINTR, -1)))
 				default:
 					t.Debugf("Restarting syscall %d after errno %d: interrupted by signal %d", t.Arch().SyscallNo(), sre, info.Signo)
 					t.Arch().RestartSyscall()
@@ -263,6 +263,19 @@ func (t *Task) deliverSignalToHandler(info *arch.SignalInfo, act arch.SignalAct)
 	if t.haveSavedSignalMask {
 		mask = t.savedSignalMask
 	}
+
+	// Set up the restorer.
+	// x86-64 should always uses SA_RESTORER, but this flag is optional on other platforms.
+	// Please see the linux code as reference:
+	// linux/arch/x86/kernel/signal.c:__setup_rt_frame()
+	// If SA_RESTORER is not configured, we can use the sigreturn trampolines
+	// the vdso provides instead.
+	// Please see the linux code as reference:
+	// linux/arch/arm64/kernel/signal.c:setup_return()
+	if act.Flags&linux.SA_RESTORER == 0 {
+		act.Restorer = t.MemoryManager().VDSOSigReturn()
+	}
+
 	if err := t.Arch().SignalSetup(st, &act, info, &alt, mask); err != nil {
 		return err
 	}
@@ -513,8 +526,6 @@ func (t *Task) canReceiveSignalLocked(sig linux.Signal) bool {
 	if t.stop != nil {
 		return false
 	}
-	// - TODO(b/38173783): No special case for when t is also the sending task,
-	// because the identity of the sender is unknown.
 	// - Do not choose tasks that have already been interrupted, as they may be
 	// busy handling another signal.
 	if len(t.interruptChan) != 0 {
@@ -705,7 +716,7 @@ func (tg *ThreadGroup) SetSignalAct(sig linux.Signal, actptr *arch.SignalAct) (a
 func (t *Task) CopyOutSignalAct(addr usermem.Addr, s *arch.SignalAct) error {
 	n := t.Arch().NewSignalAct()
 	n.SerializeFrom(s)
-	_, err := t.CopyOut(addr, n)
+	_, err := n.CopyOut(t, addr)
 	return err
 }
 
@@ -714,7 +725,7 @@ func (t *Task) CopyOutSignalAct(addr usermem.Addr, s *arch.SignalAct) error {
 func (t *Task) CopyInSignalAct(addr usermem.Addr) (arch.SignalAct, error) {
 	n := t.Arch().NewSignalAct()
 	var s arch.SignalAct
-	if _, err := t.CopyIn(addr, n); err != nil {
+	if _, err := n.CopyIn(t, addr); err != nil {
 		return s, err
 	}
 	n.DeserializeTo(&s)
@@ -726,7 +737,7 @@ func (t *Task) CopyInSignalAct(addr usermem.Addr) (arch.SignalAct, error) {
 func (t *Task) CopyOutSignalStack(addr usermem.Addr, s *arch.SignalStack) error {
 	n := t.Arch().NewSignalStack()
 	n.SerializeFrom(s)
-	_, err := t.CopyOut(addr, n)
+	_, err := n.CopyOut(t, addr)
 	return err
 }
 
@@ -735,7 +746,7 @@ func (t *Task) CopyOutSignalStack(addr usermem.Addr, s *arch.SignalStack) error
 func (t *Task) CopyInSignalStack(addr usermem.Addr) (arch.SignalStack, error) {
 	n := t.Arch().NewSignalStack()
 	var s arch.SignalStack
-	if _, err := t.CopyIn(addr, n); err != nil {
+	if _, err := n.CopyIn(t, addr); err != nil {
 		return s, err
 	}
 	n.DeserializeTo(&s)