diff options
| -rw-r--r-- | pkg/sentry/arch/signal_arm64.go | 30 | ||||
| -rw-r--r-- | pkg/sentry/kernel/task_signals.go | 13 |
2 files changed, 37 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 } diff --git a/pkg/sentry/kernel/task_signals.go b/pkg/sentry/kernel/task_signals.go index f07de2089..7d25e98f7 100644 --- a/pkg/sentry/kernel/task_signals.go +++ b/pkg/sentry/kernel/task_signals.go @@ -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 } |