From 9bd9882b81dfe2eea9af0a12bbaab35ddbd1ab47 Mon Sep 17 00:00:00 2001 From: Bin Lu Date: Mon, 11 May 2020 01:52:45 -0400 Subject: Add fpsimd support in sigreturn on Arm64 Signed-off-by: Bin Lu --- pkg/sentry/arch/signal_arm64.go | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'pkg/sentry/arch/signal_arm64.go') diff --git a/pkg/sentry/arch/signal_arm64.go b/pkg/sentry/arch/signal_arm64.go index 1cb1adf8c..642c79dda 100644 --- a/pkg/sentry/arch/signal_arm64.go +++ b/pkg/sentry/arch/signal_arm64.go @@ -19,6 +19,7 @@ import ( "syscall" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/log" "gvisor.dev/gvisor/pkg/usermem" ) @@ -134,6 +135,11 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt c.Regs.Regs[1] = uint64(infoAddr) c.Regs.Regs[2] = uint64(ucAddr) c.Regs.Regs[30] = uint64(act.Restorer) + + // Save the thread's floating point state. + c.sigFPState = append(c.sigFPState, c.aarch64FPState) + // Signal handler gets a clean floating point state. + c.aarch64FPState = newAarch64FPState() return nil } @@ -155,5 +161,21 @@ func (c *context64) SignalRestore(st *Stack, rt bool) (linux.SignalSet, SignalSt c.Regs.Sp = uc.MContext.Sp c.Regs.Pstate = uc.MContext.Pstate + // Restore floating point state. + l := len(c.sigFPState) + if l > 0 { + c.aarch64FPState = c.sigFPState[l-1] + // NOTE(cl/133042258): State save requires that any slice + // elements from '[len:cap]' to be zero value. + c.sigFPState[l-1] = nil + c.sigFPState = c.sigFPState[0 : l-1] + } else { + // This might happen if sigreturn(2) calls are unbalanced with + // respect to signal handler entries. This is not expected so + // don't bother to do anything fancy with the floating point + // state. + log.Warningf("sigreturn unable to restore application fpstate") + } + return uc.Sigset, uc.Stack, nil } -- cgit v1.2.3