From a369c88c0c4ece5239855000d28df045111c1be7 Mon Sep 17 00:00:00 2001 From: Bin Lu Date: Wed, 29 Jan 2020 04:33:06 -0500 Subject: Lazy-fpsimd support patch series#1: add Arm64-fpsimd support to arch module This patch defines the structures and adds the implementations for fpsimd initialization. Signed-off-by: Bin Lu --- pkg/sentry/arch/arch_arm64.go | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'pkg/sentry/arch/arch_arm64.go') diff --git a/pkg/sentry/arch/arch_arm64.go b/pkg/sentry/arch/arch_arm64.go index 94f1a808f..372b650b9 100644 --- a/pkg/sentry/arch/arch_arm64.go +++ b/pkg/sentry/arch/arch_arm64.go @@ -68,6 +68,7 @@ const ( // context64 represents an ARM64 context. type context64 struct { State + sigFPState []aarch64FPState // fpstate to be restored on sigreturn. } // Arch implements Context.Arch. @@ -75,10 +76,19 @@ func (c *context64) Arch() Arch { return ARM64 } +func (c *context64) copySigFPState() []aarch64FPState { + var sigfps []aarch64FPState + for _, s := range c.sigFPState { + sigfps = append(sigfps, s.fork()) + } + return sigfps +} + // Fork returns an exact copy of this context. func (c *context64) Fork() Context { return &context64{ - State: c.State.Fork(), + State: c.State.Fork(), + sigFPState: c.copySigFPState(), } } @@ -137,8 +147,8 @@ func (c *context64) SetTLS(value uintptr) bool { return false } -// SetRSEQInterruptedIP implements Context.SetRSEQInterruptedIP. -func (c *context64) SetRSEQInterruptedIP(value uintptr) { +// SetOldRSeqInterruptedIP implements Context.SetOldRSeqInterruptedIP. +func (c *context64) SetOldRSeqInterruptedIP(value uintptr) { c.Regs.Regs[3] = uint64(value) } -- cgit v1.2.3 From 413a9b7fdc14f8bff660e1988e3ef0355dd4e6c6 Mon Sep 17 00:00:00 2001 From: Andrei Vagin Date: Fri, 21 Feb 2020 11:00:11 -0800 Subject: Define CPUIDInstruction for arm64 There is no cpuid instruction on arm64, so we need to defined it just to avoid a compile time error. Signed-off-by: Andrei Vagin --- pkg/sentry/arch/arch_arm64.go | 5 +++++ pkg/sentry/kernel/task_run.go | 41 ++++++++++++++++++++++++++++------------- 2 files changed, 33 insertions(+), 13 deletions(-) (limited to 'pkg/sentry/arch/arch_arm64.go') diff --git a/pkg/sentry/arch/arch_arm64.go b/pkg/sentry/arch/arch_arm64.go index 372b650b9..885115ae2 100644 --- a/pkg/sentry/arch/arch_arm64.go +++ b/pkg/sentry/arch/arch_arm64.go @@ -53,6 +53,11 @@ const ( preferredPIELoadAddr usermem.Addr = maxAddr64 / 6 * 5 ) +var ( + // CPUIDInstruction doesn't exist on ARM64. + CPUIDInstruction = []byte{} +) + // These constants are selected as heuristics to help make the Platform's // potentially limited address space conform as closely to Linux as possible. const ( diff --git a/pkg/sentry/kernel/task_run.go b/pkg/sentry/kernel/task_run.go index 5568c91bc..799cbcd93 100644 --- a/pkg/sentry/kernel/task_run.go +++ b/pkg/sentry/kernel/task_run.go @@ -126,13 +126,39 @@ func (t *Task) doStop() { } } +func (*runApp) handleCPUIDInstruction(t *Task) error { + if len(arch.CPUIDInstruction) == 0 { + // CPUID emulation isn't supported, but this code can be + // executed, because the ptrace platform returns + // ErrContextSignalCPUID on page faults too. Look at + // pkg/sentry/platform/ptrace/ptrace.go:context.Switch for more + // details. + return platform.ErrContextSignal + } + // Is this a CPUID instruction? + region := trace.StartRegion(t.traceContext, cpuidRegion) + expected := arch.CPUIDInstruction[:] + found := make([]byte, len(expected)) + _, err := t.CopyIn(usermem.Addr(t.Arch().IP()), &found) + if err == nil && bytes.Equal(expected, found) { + // Skip the cpuid instruction. + t.Arch().CPUIDEmulate(t) + t.Arch().SetIP(t.Arch().IP() + uintptr(len(expected))) + region.End() + + return nil + } + region.End() // Not an actual CPUID, but required copy-in. + return platform.ErrContextSignal +} + // The runApp state checks for interrupts before executing untrusted // application code. // // +stateify savable type runApp struct{} -func (*runApp) execute(t *Task) taskRunState { +func (app *runApp) execute(t *Task) taskRunState { if t.interrupted() { // Checkpointing instructs tasks to stop by sending an interrupt, so we // must check for stops before entering runInterrupt (instead of @@ -237,21 +263,10 @@ func (*runApp) execute(t *Task) taskRunState { return (*runApp)(nil) case platform.ErrContextSignalCPUID: - // Is this a CPUID instruction? - region := trace.StartRegion(t.traceContext, cpuidRegion) - expected := arch.CPUIDInstruction[:] - found := make([]byte, len(expected)) - _, err := t.CopyIn(usermem.Addr(t.Arch().IP()), &found) - if err == nil && bytes.Equal(expected, found) { - // Skip the cpuid instruction. - t.Arch().CPUIDEmulate(t) - t.Arch().SetIP(t.Arch().IP() + uintptr(len(expected))) - region.End() - + if err := app.handleCPUIDInstruction(t); err == nil { // Resume execution. return (*runApp)(nil) } - region.End() // Not an actual CPUID, but required copy-in. // The instruction at the given RIP was not a CPUID, and we // fallthrough to the default signal deliver behavior below. -- cgit v1.2.3