Merge pull request #1819 from lubinszARM:pr_signal_2

PiperOrigin-RevId: 308100771

1 files changed, 24 insertions, 6 deletions

diff --git a/pkg/sentry/arch/signal_arm64.go b/pkg/sentry/arch/signal_arm64.go
index 0c1db4b13..1cb1adf8c 100644
--- a/pkg/sentry/arch/signal_arm64.go
+++ b/pkg/sentry/arch/signal_arm64.go
@@ -98,9 +98,12 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt
 	if ucSize < 0 {
 		panic("can't get size of UContext64")
 	}
-	// st.Arch.Width() is for the restorer address. sizeof(siginfo) == 128.
-	frameSize := int(st.Arch.Width()) + ucSize + 128
-	frameBottom := (sp-usermem.Addr(frameSize)) & ^usermem.Addr(15) - 8
+
+	// frameSize = ucSize + sizeof(siginfo).
+	// sizeof(siginfo) == 128.
+	// R30 stores the restorer address.
+	frameSize := ucSize + 128
+	frameBottom := (sp - usermem.Addr(frameSize)) & ^usermem.Addr(15)
 	sp = frameBottom + usermem.Addr(frameSize)
 	st.Bottom = sp
 
@@ -130,12 +133,27 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt
 	c.Regs.Regs[0] = uint64(info.Signo)
 	c.Regs.Regs[1] = uint64(infoAddr)
 	c.Regs.Regs[2] = uint64(ucAddr)
-
+	c.Regs.Regs[30] = uint64(act.Restorer)
 	return nil
 }
 
 // SignalRestore implements Context.SignalRestore.
-// Only used on intel.
 func (c *context64) SignalRestore(st *Stack, rt bool) (linux.SignalSet, SignalStack, error) {
-	return 0, SignalStack{}, nil
+	// Copy out the stack frame.
+	var uc UContext64
+	if _, err := st.Pop(&uc); err != nil {
+		return 0, SignalStack{}, err
+	}
+	var info SignalInfo
+	if _, err := st.Pop(&info); err != nil {
+		return 0, SignalStack{}, err
+	}
+
+	// Restore registers.
+	c.Regs.Regs = uc.MContext.Regs
+	c.Regs.Pc = uc.MContext.Pc
+	c.Regs.Sp = uc.MContext.Sp
+	c.Regs.Pstate = uc.MContext.Pstate
+
+	return uc.Sigset, uc.Stack, nil
 }