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-rw-r--r--pkg/sentry/platform/kvm/BUILD2
-rw-r--r--pkg/sentry/platform/kvm/address_space.go73
-rw-r--r--pkg/sentry/platform/kvm/bluepill_allocator.go (renamed from pkg/sentry/platform/kvm/allocator.go)52
-rw-r--r--pkg/sentry/platform/kvm/bluepill_amd64.go12
-rw-r--r--pkg/sentry/platform/kvm/bluepill_arm64.go4
-rw-r--r--pkg/sentry/platform/kvm/bluepill_unsafe.go9
-rw-r--r--pkg/sentry/platform/kvm/machine.go52
-rw-r--r--pkg/sentry/platform/kvm/machine_amd64.go34
-rw-r--r--pkg/sentry/platform/kvm/machine_amd64_unsafe.go2
-rw-r--r--pkg/sentry/platform/kvm/machine_unsafe.go2
-rw-r--r--pkg/sentry/platform/ring0/kernel.go24
-rw-r--r--pkg/sentry/platform/ring0/kernel_amd64.go12
-rw-r--r--pkg/sentry/platform/ring0/pagetables/allocator.go11
-rw-r--r--pkg/sentry/platform/ring0/pagetables/pagetables.go8
14 files changed, 182 insertions, 115 deletions
diff --git a/pkg/sentry/platform/kvm/BUILD b/pkg/sentry/platform/kvm/BUILD
index 159f7eafd..4792454c4 100644
--- a/pkg/sentry/platform/kvm/BUILD
+++ b/pkg/sentry/platform/kvm/BUILD
@@ -6,8 +6,8 @@ go_library(
name = "kvm",
srcs = [
"address_space.go",
- "allocator.go",
"bluepill.go",
+ "bluepill_allocator.go",
"bluepill_amd64.go",
"bluepill_amd64.s",
"bluepill_amd64_unsafe.go",
diff --git a/pkg/sentry/platform/kvm/address_space.go b/pkg/sentry/platform/kvm/address_space.go
index be213bfe8..faf1d5e1c 100644
--- a/pkg/sentry/platform/kvm/address_space.go
+++ b/pkg/sentry/platform/kvm/address_space.go
@@ -26,16 +26,15 @@ import (
// dirtySet tracks vCPUs for invalidation.
type dirtySet struct {
- vCPUs []uint64
+ vCPUMasks []uint64
}
// forEach iterates over all CPUs in the dirty set.
+//
+//go:nosplit
func (ds *dirtySet) forEach(m *machine, fn func(c *vCPU)) {
- m.mu.RLock()
- defer m.mu.RUnlock()
-
- for index := range ds.vCPUs {
- mask := atomic.SwapUint64(&ds.vCPUs[index], 0)
+ for index := range ds.vCPUMasks {
+ mask := atomic.SwapUint64(&ds.vCPUMasks[index], 0)
if mask != 0 {
for bit := 0; bit < 64; bit++ {
if mask&(1<<uint64(bit)) == 0 {
@@ -54,7 +53,7 @@ func (ds *dirtySet) mark(c *vCPU) bool {
index := uint64(c.id) / 64
bit := uint64(1) << uint(c.id%64)
- oldValue := atomic.LoadUint64(&ds.vCPUs[index])
+ oldValue := atomic.LoadUint64(&ds.vCPUMasks[index])
if oldValue&bit != 0 {
return false // Not clean.
}
@@ -62,7 +61,7 @@ func (ds *dirtySet) mark(c *vCPU) bool {
// Set the bit unilaterally, and ensure that a flush takes place. Note
// that it's possible for races to occur here, but since the flush is
// taking place long after these lines there's no race in practice.
- atomicbitops.OrUint64(&ds.vCPUs[index], bit)
+ atomicbitops.OrUint64(&ds.vCPUMasks[index], bit)
return true // Previously clean.
}
@@ -113,7 +112,12 @@ type hostMapEntry struct {
length uintptr
}
-func (as *addressSpace) mapHost(addr usermem.Addr, m hostMapEntry, at usermem.AccessType) (inv bool) {
+// mapLocked maps the given host entry.
+//
+// +checkescape:hard,stack
+//
+//go:nosplit
+func (as *addressSpace) mapLocked(addr usermem.Addr, m hostMapEntry, at usermem.AccessType) (inv bool) {
for m.length > 0 {
physical, length, ok := translateToPhysical(m.addr)
if !ok {
@@ -133,18 +137,10 @@ func (as *addressSpace) mapHost(addr usermem.Addr, m hostMapEntry, at usermem.Ac
// important; if the pagetable mappings were installed before
// ensuring the physical pages were available, then some other
// thread could theoretically access them.
- //
- // Due to the way KVM's shadow paging implementation works,
- // modifications to the page tables while in host mode may not
- // be trapped, leading to the shadow pages being out of sync.
- // Therefore, we need to ensure that we are in guest mode for
- // page table modifications. See the call to bluepill, below.
- as.machine.retryInGuest(func() {
- inv = as.pageTables.Map(addr, length, pagetables.MapOpts{
- AccessType: at,
- User: true,
- }, physical) || inv
- })
+ inv = as.pageTables.Map(addr, length, pagetables.MapOpts{
+ AccessType: at,
+ User: true,
+ }, physical) || inv
m.addr += length
m.length -= length
addr += usermem.Addr(length)
@@ -176,6 +172,10 @@ func (as *addressSpace) MapFile(addr usermem.Addr, f platform.File, fr platform.
return err
}
+ // See block in mapLocked.
+ as.pageTables.Allocator.(*allocator).cpu = as.machine.Get()
+ defer as.machine.Put(as.pageTables.Allocator.(*allocator).cpu)
+
// Map the mappings in the sentry's address space (guest physical memory)
// into the application's address space (guest virtual memory).
inv := false
@@ -190,7 +190,12 @@ func (as *addressSpace) MapFile(addr usermem.Addr, f platform.File, fr platform.
_ = s[i] // Touch to commit.
}
}
- prev := as.mapHost(addr, hostMapEntry{
+
+ // See bluepill_allocator.go.
+ bluepill(as.pageTables.Allocator.(*allocator).cpu)
+
+ // Perform the mapping.
+ prev := as.mapLocked(addr, hostMapEntry{
addr: b.Addr(),
length: uintptr(b.Len()),
}, at)
@@ -204,17 +209,27 @@ func (as *addressSpace) MapFile(addr usermem.Addr, f platform.File, fr platform.
return nil
}
+// unmapLocked is an escape-checked wrapped around Unmap.
+//
+// +checkescape:hard,stack
+//
+//go:nosplit
+func (as *addressSpace) unmapLocked(addr usermem.Addr, length uint64) bool {
+ return as.pageTables.Unmap(addr, uintptr(length))
+}
+
// Unmap unmaps the given range by calling pagetables.PageTables.Unmap.
func (as *addressSpace) Unmap(addr usermem.Addr, length uint64) {
as.mu.Lock()
defer as.mu.Unlock()
- // See above re: retryInGuest.
- var prev bool
- as.machine.retryInGuest(func() {
- prev = as.pageTables.Unmap(addr, uintptr(length)) || prev
- })
- if prev {
+ // See above & bluepill_allocator.go.
+ as.pageTables.Allocator.(*allocator).cpu = as.machine.Get()
+ defer as.machine.Put(as.pageTables.Allocator.(*allocator).cpu)
+ bluepill(as.pageTables.Allocator.(*allocator).cpu)
+
+ if prev := as.unmapLocked(addr, length); prev {
+ // Invalidate all active vCPUs.
as.invalidate()
// Recycle any freed intermediate pages.
@@ -227,7 +242,7 @@ func (as *addressSpace) Release() {
as.Unmap(0, ^uint64(0))
// Free all pages from the allocator.
- as.pageTables.Allocator.(allocator).base.Drain()
+ as.pageTables.Allocator.(*allocator).base.Drain()
// Drop all cached machine references.
as.machine.dropPageTables(as.pageTables)
diff --git a/pkg/sentry/platform/kvm/allocator.go b/pkg/sentry/platform/kvm/bluepill_allocator.go
index 3f35414bb..9485e1301 100644
--- a/pkg/sentry/platform/kvm/allocator.go
+++ b/pkg/sentry/platform/kvm/bluepill_allocator.go
@@ -21,56 +21,80 @@ import (
)
type allocator struct {
- base *pagetables.RuntimeAllocator
+ base pagetables.RuntimeAllocator
+
+ // cpu must be set prior to any pagetable operation.
+ //
+ // Due to the way KVM's shadow paging implementation works,
+ // modifications to the page tables while in host mode may not be
+ // trapped, leading to the shadow pages being out of sync. Therefore,
+ // we need to ensure that we are in guest mode for page table
+ // modifications. See the call to bluepill, below.
+ cpu *vCPU
}
// newAllocator is used to define the allocator.
-func newAllocator() allocator {
- return allocator{
- base: pagetables.NewRuntimeAllocator(),
- }
+func newAllocator() *allocator {
+ a := new(allocator)
+ a.base.Init()
+ return a
}
// NewPTEs implements pagetables.Allocator.NewPTEs.
//
+// +checkescape:all
+//
//go:nosplit
-func (a allocator) NewPTEs() *pagetables.PTEs {
- return a.base.NewPTEs()
+func (a *allocator) NewPTEs() *pagetables.PTEs {
+ ptes := a.base.NewPTEs() // escapes: bluepill below.
+ if a.cpu != nil {
+ bluepill(a.cpu)
+ }
+ return ptes
}
// PhysicalFor returns the physical address for a set of PTEs.
//
+// +checkescape:all
+//
//go:nosplit
-func (a allocator) PhysicalFor(ptes *pagetables.PTEs) uintptr {
+func (a *allocator) PhysicalFor(ptes *pagetables.PTEs) uintptr {
virtual := a.base.PhysicalFor(ptes)
physical, _, ok := translateToPhysical(virtual)
if !ok {
- panic(fmt.Sprintf("PhysicalFor failed for %p", ptes))
+ panic(fmt.Sprintf("PhysicalFor failed for %p", ptes)) // escapes: panic.
}
return physical
}
// LookupPTEs implements pagetables.Allocator.LookupPTEs.
//
+// +checkescape:all
+//
//go:nosplit
-func (a allocator) LookupPTEs(physical uintptr) *pagetables.PTEs {
+func (a *allocator) LookupPTEs(physical uintptr) *pagetables.PTEs {
virtualStart, physicalStart, _, ok := calculateBluepillFault(physical, physicalRegions)
if !ok {
- panic(fmt.Sprintf("LookupPTEs failed for 0x%x", physical))
+ panic(fmt.Sprintf("LookupPTEs failed for 0x%x", physical)) // escapes: panic.
}
return a.base.LookupPTEs(virtualStart + (physical - physicalStart))
}
// FreePTEs implements pagetables.Allocator.FreePTEs.
//
+// +checkescape:all
+//
//go:nosplit
-func (a allocator) FreePTEs(ptes *pagetables.PTEs) {
- a.base.FreePTEs(ptes)
+func (a *allocator) FreePTEs(ptes *pagetables.PTEs) {
+ a.base.FreePTEs(ptes) // escapes: bluepill below.
+ if a.cpu != nil {
+ bluepill(a.cpu)
+ }
}
// Recycle implements pagetables.Allocator.Recycle.
//
//go:nosplit
-func (a allocator) Recycle() {
+func (a *allocator) Recycle() {
a.base.Recycle()
}
diff --git a/pkg/sentry/platform/kvm/bluepill_amd64.go b/pkg/sentry/platform/kvm/bluepill_amd64.go
index 133c2203d..ddc1554d5 100644
--- a/pkg/sentry/platform/kvm/bluepill_amd64.go
+++ b/pkg/sentry/platform/kvm/bluepill_amd64.go
@@ -63,6 +63,8 @@ func bluepillArchEnter(context *arch.SignalContext64) *vCPU {
// KernelSyscall handles kernel syscalls.
//
+// +checkescape:all
+//
//go:nosplit
func (c *vCPU) KernelSyscall() {
regs := c.Registers()
@@ -72,13 +74,15 @@ func (c *vCPU) KernelSyscall() {
// We only trigger a bluepill entry in the bluepill function, and can
// therefore be guaranteed that there is no floating point state to be
// loaded on resuming from halt. We only worry about saving on exit.
- ring0.SaveFloatingPoint((*byte)(c.floatingPointState))
+ ring0.SaveFloatingPoint((*byte)(c.floatingPointState)) // escapes: no.
ring0.Halt()
- ring0.WriteFS(uintptr(regs.Fs_base)) // Reload host segment.
+ ring0.WriteFS(uintptr(regs.Fs_base)) // escapes: no, reload host segment.
}
// KernelException handles kernel exceptions.
//
+// +checkescape:all
+//
//go:nosplit
func (c *vCPU) KernelException(vector ring0.Vector) {
regs := c.Registers()
@@ -89,9 +93,9 @@ func (c *vCPU) KernelException(vector ring0.Vector) {
regs.Rip = 0
}
// See above.
- ring0.SaveFloatingPoint((*byte)(c.floatingPointState))
+ ring0.SaveFloatingPoint((*byte)(c.floatingPointState)) // escapes: no.
ring0.Halt()
- ring0.WriteFS(uintptr(regs.Fs_base)) // Reload host segment.
+ ring0.WriteFS(uintptr(regs.Fs_base)) // escapes: no; reload host segment.
}
// bluepillArchExit is called during bluepillEnter.
diff --git a/pkg/sentry/platform/kvm/bluepill_arm64.go b/pkg/sentry/platform/kvm/bluepill_arm64.go
index c215d443c..83643c602 100644
--- a/pkg/sentry/platform/kvm/bluepill_arm64.go
+++ b/pkg/sentry/platform/kvm/bluepill_arm64.go
@@ -66,6 +66,8 @@ func bluepillArchExit(c *vCPU, context *arch.SignalContext64) {
// KernelSyscall handles kernel syscalls.
//
+// +checkescape:all
+//
//go:nosplit
func (c *vCPU) KernelSyscall() {
regs := c.Registers()
@@ -88,6 +90,8 @@ func (c *vCPU) KernelSyscall() {
// KernelException handles kernel exceptions.
//
+// +checkescape:all
+//
//go:nosplit
func (c *vCPU) KernelException(vector ring0.Vector) {
regs := c.Registers()
diff --git a/pkg/sentry/platform/kvm/bluepill_unsafe.go b/pkg/sentry/platform/kvm/bluepill_unsafe.go
index 2407014e9..c025aa0bb 100644
--- a/pkg/sentry/platform/kvm/bluepill_unsafe.go
+++ b/pkg/sentry/platform/kvm/bluepill_unsafe.go
@@ -64,6 +64,8 @@ func bluepillArchContext(context unsafe.Pointer) *arch.SignalContext64 {
// signal stack. It should only execute raw system calls and functions that are
// explicitly marked go:nosplit.
//
+// +checkescape:all
+//
//go:nosplit
func bluepillHandler(context unsafe.Pointer) {
// Sanitize the registers; interrupts must always be disabled.
@@ -82,7 +84,8 @@ func bluepillHandler(context unsafe.Pointer) {
}
for {
- switch _, _, errno := syscall.RawSyscall(syscall.SYS_IOCTL, uintptr(c.fd), _KVM_RUN, 0); errno {
+ _, _, errno := syscall.RawSyscall(syscall.SYS_IOCTL, uintptr(c.fd), _KVM_RUN, 0) // escapes: no.
+ switch errno {
case 0: // Expected case.
case syscall.EINTR:
// First, we process whatever pending signal
@@ -90,7 +93,7 @@ func bluepillHandler(context unsafe.Pointer) {
// currently, all signals are masked and the signal
// must have been delivered directly to this thread.
timeout := syscall.Timespec{}
- sig, _, errno := syscall.RawSyscall6(
+ sig, _, errno := syscall.RawSyscall6( // escapes: no.
syscall.SYS_RT_SIGTIMEDWAIT,
uintptr(unsafe.Pointer(&bounceSignalMask)),
0, // siginfo.
@@ -125,7 +128,7 @@ func bluepillHandler(context unsafe.Pointer) {
// MMIO exit we receive EFAULT from the run ioctl. We
// always inject an NMI here since we may be in kernel
// mode and have interrupts disabled.
- if _, _, errno := syscall.RawSyscall(
+ if _, _, errno := syscall.RawSyscall( // escapes: no.
syscall.SYS_IOCTL,
uintptr(c.fd),
_KVM_NMI, 0); errno != 0 {
diff --git a/pkg/sentry/platform/kvm/machine.go b/pkg/sentry/platform/kvm/machine.go
index f1afc74dc..6c54712d1 100644
--- a/pkg/sentry/platform/kvm/machine.go
+++ b/pkg/sentry/platform/kvm/machine.go
@@ -52,16 +52,19 @@ type machine struct {
// available is notified when vCPUs are available.
available sync.Cond
- // vCPUs are the machine vCPUs.
+ // vCPUsByTID are the machine vCPUs.
//
// These are populated dynamically.
- vCPUs map[uint64]*vCPU
+ vCPUsByTID map[uint64]*vCPU
// vCPUsByID are the machine vCPUs, can be indexed by the vCPU's ID.
- vCPUsByID map[int]*vCPU
+ vCPUsByID []*vCPU
// maxVCPUs is the maximum number of vCPUs supported by the machine.
maxVCPUs int
+
+ // nextID is the next vCPU ID.
+ nextID uint32
}
const (
@@ -137,9 +140,8 @@ type dieState struct {
//
// Precondition: mu must be held.
func (m *machine) newVCPU() *vCPU {
- id := len(m.vCPUs)
-
// Create the vCPU.
+ id := int(atomic.AddUint32(&m.nextID, 1) - 1)
fd, _, errno := syscall.RawSyscall(syscall.SYS_IOCTL, uintptr(m.fd), _KVM_CREATE_VCPU, uintptr(id))
if errno != 0 {
panic(fmt.Sprintf("error creating new vCPU: %v", errno))
@@ -176,11 +178,7 @@ func (m *machine) newVCPU() *vCPU {
// newMachine returns a new VM context.
func newMachine(vm int) (*machine, error) {
// Create the machine.
- m := &machine{
- fd: vm,
- vCPUs: make(map[uint64]*vCPU),
- vCPUsByID: make(map[int]*vCPU),
- }
+ m := &machine{fd: vm}
m.available.L = &m.mu
m.kernel.Init(ring0.KernelOpts{
PageTables: pagetables.New(newAllocator()),
@@ -194,6 +192,10 @@ func newMachine(vm int) (*machine, error) {
}
log.Debugf("The maximum number of vCPUs is %d.", m.maxVCPUs)
+ // Create the vCPUs map/slices.
+ m.vCPUsByTID = make(map[uint64]*vCPU)
+ m.vCPUsByID = make([]*vCPU, m.maxVCPUs)
+
// Apply the physical mappings. Note that these mappings may point to
// guest physical addresses that are not actually available. These
// physical pages are mapped on demand, see kernel_unsafe.go.
@@ -274,6 +276,8 @@ func newMachine(vm int) (*machine, error) {
// not available. This attempts to be efficient for calls in the hot path.
//
// This panics on error.
+//
+//go:nosplit
func (m *machine) mapPhysical(physical, length uintptr, phyRegions []physicalRegion, flags uint32) {
for end := physical + length; physical < end; {
_, physicalStart, length, ok := calculateBluepillFault(physical, phyRegions)
@@ -304,7 +308,11 @@ func (m *machine) Destroy() {
runtime.SetFinalizer(m, nil)
// Destroy vCPUs.
- for _, c := range m.vCPUs {
+ for _, c := range m.vCPUsByID {
+ if c == nil {
+ continue
+ }
+
// Ensure the vCPU is not still running in guest mode. This is
// possible iff teardown has been done by other threads, and
// somehow a single thread has not executed any system calls.
@@ -337,7 +345,7 @@ func (m *machine) Get() *vCPU {
tid := procid.Current()
// Check for an exact match.
- if c := m.vCPUs[tid]; c != nil {
+ if c := m.vCPUsByTID[tid]; c != nil {
c.lock()
m.mu.RUnlock()
return c
@@ -356,7 +364,7 @@ func (m *machine) Get() *vCPU {
tid = procid.Current()
// Recheck for an exact match.
- if c := m.vCPUs[tid]; c != nil {
+ if c := m.vCPUsByTID[tid]; c != nil {
c.lock()
m.mu.Unlock()
return c
@@ -364,10 +372,10 @@ func (m *machine) Get() *vCPU {
for {
// Scan for an available vCPU.
- for origTID, c := range m.vCPUs {
+ for origTID, c := range m.vCPUsByTID {
if atomic.CompareAndSwapUint32(&c.state, vCPUReady, vCPUUser) {
- delete(m.vCPUs, origTID)
- m.vCPUs[tid] = c
+ delete(m.vCPUsByTID, origTID)
+ m.vCPUsByTID[tid] = c
m.mu.Unlock()
c.loadSegments(tid)
return c
@@ -375,17 +383,17 @@ func (m *machine) Get() *vCPU {
}
// Create a new vCPU (maybe).
- if len(m.vCPUs) < m.maxVCPUs {
+ if int(m.nextID) < m.maxVCPUs {
c := m.newVCPU()
c.lock()
- m.vCPUs[tid] = c
+ m.vCPUsByTID[tid] = c
m.mu.Unlock()
c.loadSegments(tid)
return c
}
// Scan for something not in user mode.
- for origTID, c := range m.vCPUs {
+ for origTID, c := range m.vCPUsByTID {
if !atomic.CompareAndSwapUint32(&c.state, vCPUGuest, vCPUGuest|vCPUWaiter) {
continue
}
@@ -403,8 +411,8 @@ func (m *machine) Get() *vCPU {
}
// Steal the vCPU.
- delete(m.vCPUs, origTID)
- m.vCPUs[tid] = c
+ delete(m.vCPUsByTID, origTID)
+ m.vCPUsByTID[tid] = c
m.mu.Unlock()
c.loadSegments(tid)
return c
@@ -431,7 +439,7 @@ func (m *machine) Put(c *vCPU) {
// newDirtySet returns a new dirty set.
func (m *machine) newDirtySet() *dirtySet {
return &dirtySet{
- vCPUs: make([]uint64, (m.maxVCPUs+63)/64, (m.maxVCPUs+63)/64),
+ vCPUMasks: make([]uint64, (m.maxVCPUs+63)/64, (m.maxVCPUs+63)/64),
}
}
diff --git a/pkg/sentry/platform/kvm/machine_amd64.go b/pkg/sentry/platform/kvm/machine_amd64.go
index 923ce3909..acc823ba6 100644
--- a/pkg/sentry/platform/kvm/machine_amd64.go
+++ b/pkg/sentry/platform/kvm/machine_amd64.go
@@ -51,9 +51,10 @@ func (m *machine) initArchState() error {
recover()
debug.SetPanicOnFault(old)
}()
- m.retryInGuest(func() {
- ring0.SetCPUIDFaulting(true)
- })
+ c := m.Get()
+ defer m.Put(c)
+ bluepill(c)
+ ring0.SetCPUIDFaulting(true)
return nil
}
@@ -89,8 +90,8 @@ func (m *machine) dropPageTables(pt *pagetables.PageTables) {
defer m.mu.Unlock()
// Clear from all PCIDs.
- for _, c := range m.vCPUs {
- if c.PCIDs != nil {
+ for _, c := range m.vCPUsByID {
+ if c != nil && c.PCIDs != nil {
c.PCIDs.Drop(pt)
}
}
@@ -335,29 +336,6 @@ func (c *vCPU) SwitchToUser(switchOpts ring0.SwitchOpts, info *arch.SignalInfo)
}
}
-// retryInGuest runs the given function in guest mode.
-//
-// If the function does not complete in guest mode (due to execution of a
-// system call due to a GC stall, for example), then it will be retried. The
-// given function must be idempotent as a result of the retry mechanism.
-func (m *machine) retryInGuest(fn func()) {
- c := m.Get()
- defer m.Put(c)
- for {
- c.ClearErrorCode() // See below.
- bluepill(c) // Force guest mode.
- fn() // Execute the given function.
- _, user := c.ErrorCode()
- if user {
- // If user is set, then we haven't bailed back to host
- // mode via a kernel exception or system call. We
- // consider the full function to have executed in guest
- // mode and we can return.
- break
- }
- }
-}
-
// On x86 platform, the flags for "setMemoryRegion" can always be set as 0.
// There is no need to return read-only physicalRegions.
func rdonlyRegionsForSetMem() (phyRegions []physicalRegion) {
diff --git a/pkg/sentry/platform/kvm/machine_amd64_unsafe.go b/pkg/sentry/platform/kvm/machine_amd64_unsafe.go
index 7156c245f..290f035dd 100644
--- a/pkg/sentry/platform/kvm/machine_amd64_unsafe.go
+++ b/pkg/sentry/platform/kvm/machine_amd64_unsafe.go
@@ -154,7 +154,7 @@ func (c *vCPU) setUserRegisters(uregs *userRegs) error {
//
//go:nosplit
func (c *vCPU) getUserRegisters(uregs *userRegs) syscall.Errno {
- if _, _, errno := syscall.RawSyscall(
+ if _, _, errno := syscall.RawSyscall( // escapes: no.
syscall.SYS_IOCTL,
uintptr(c.fd),
_KVM_GET_REGS,
diff --git a/pkg/sentry/platform/kvm/machine_unsafe.go b/pkg/sentry/platform/kvm/machine_unsafe.go
index de7df4f80..9f86f6a7a 100644
--- a/pkg/sentry/platform/kvm/machine_unsafe.go
+++ b/pkg/sentry/platform/kvm/machine_unsafe.go
@@ -115,7 +115,7 @@ func (a *atomicAddressSpace) get() *addressSpace {
//
//go:nosplit
func (c *vCPU) notify() {
- _, _, errno := syscall.RawSyscall6(
+ _, _, errno := syscall.RawSyscall6( // escapes: no.
syscall.SYS_FUTEX,
uintptr(unsafe.Pointer(&c.state)),
linux.FUTEX_WAKE|linux.FUTEX_PRIVATE_FLAG,
diff --git a/pkg/sentry/platform/ring0/kernel.go b/pkg/sentry/platform/ring0/kernel.go
index 900c0bba7..021693791 100644
--- a/pkg/sentry/platform/ring0/kernel.go
+++ b/pkg/sentry/platform/ring0/kernel.go
@@ -31,23 +31,39 @@ type defaultHooks struct{}
// KernelSyscall implements Hooks.KernelSyscall.
//
+// +checkescape:all
+//
//go:nosplit
-func (defaultHooks) KernelSyscall() { Halt() }
+func (defaultHooks) KernelSyscall() {
+ Halt()
+}
// KernelException implements Hooks.KernelException.
//
+// +checkescape:all
+//
//go:nosplit
-func (defaultHooks) KernelException(Vector) { Halt() }
+func (defaultHooks) KernelException(Vector) {
+ Halt()
+}
// kernelSyscall is a trampoline.
//
+// +checkescape:hard,stack
+//
//go:nosplit
-func kernelSyscall(c *CPU) { c.hooks.KernelSyscall() }
+func kernelSyscall(c *CPU) {
+ c.hooks.KernelSyscall()
+}
// kernelException is a trampoline.
//
+// +checkescape:hard,stack
+//
//go:nosplit
-func kernelException(c *CPU, vector Vector) { c.hooks.KernelException(vector) }
+func kernelException(c *CPU, vector Vector) {
+ c.hooks.KernelException(vector)
+}
// Init initializes a new CPU.
//
diff --git a/pkg/sentry/platform/ring0/kernel_amd64.go b/pkg/sentry/platform/ring0/kernel_amd64.go
index 0feff8778..d37981dbf 100644
--- a/pkg/sentry/platform/ring0/kernel_amd64.go
+++ b/pkg/sentry/platform/ring0/kernel_amd64.go
@@ -178,6 +178,8 @@ func IsCanonical(addr uint64) bool {
//
// Precondition: the Rip, Rsp, Fs and Gs registers must be canonical.
//
+// +checkescape:all
+//
//go:nosplit
func (c *CPU) SwitchToUser(switchOpts SwitchOpts) (vector Vector) {
userCR3 := switchOpts.PageTables.CR3(!switchOpts.Flush, switchOpts.UserPCID)
@@ -192,9 +194,9 @@ func (c *CPU) SwitchToUser(switchOpts SwitchOpts) (vector Vector) {
// Perform the switch.
swapgs() // GS will be swapped on return.
- WriteFS(uintptr(regs.Fs_base)) // Set application FS.
- WriteGS(uintptr(regs.Gs_base)) // Set application GS.
- LoadFloatingPoint(switchOpts.FloatingPointState) // Copy in floating point.
+ WriteFS(uintptr(regs.Fs_base)) // escapes: no. Set application FS.
+ WriteGS(uintptr(regs.Gs_base)) // escapes: no. Set application GS.
+ LoadFloatingPoint(switchOpts.FloatingPointState) // escapes: no. Copy in floating point.
jumpToKernel() // Switch to upper half.
writeCR3(uintptr(userCR3)) // Change to user address space.
if switchOpts.FullRestore {
@@ -204,8 +206,8 @@ func (c *CPU) SwitchToUser(switchOpts SwitchOpts) (vector Vector) {
}
writeCR3(uintptr(kernelCR3)) // Return to kernel address space.
jumpToUser() // Return to lower half.
- SaveFloatingPoint(switchOpts.FloatingPointState) // Copy out floating point.
- WriteFS(uintptr(c.registers.Fs_base)) // Restore kernel FS.
+ SaveFloatingPoint(switchOpts.FloatingPointState) // escapes: no. Copy out floating point.
+ WriteFS(uintptr(c.registers.Fs_base)) // escapes: no. Restore kernel FS.
return
}
diff --git a/pkg/sentry/platform/ring0/pagetables/allocator.go b/pkg/sentry/platform/ring0/pagetables/allocator.go
index 23fd5c352..8d75b7599 100644
--- a/pkg/sentry/platform/ring0/pagetables/allocator.go
+++ b/pkg/sentry/platform/ring0/pagetables/allocator.go
@@ -53,9 +53,14 @@ type RuntimeAllocator struct {
// NewRuntimeAllocator returns an allocator that uses runtime allocation.
func NewRuntimeAllocator() *RuntimeAllocator {
- return &RuntimeAllocator{
- used: make(map[*PTEs]struct{}),
- }
+ r := new(RuntimeAllocator)
+ r.Init()
+ return r
+}
+
+// Init initializes a RuntimeAllocator.
+func (r *RuntimeAllocator) Init() {
+ r.used = make(map[*PTEs]struct{})
}
// Recycle returns freed pages to the pool.
diff --git a/pkg/sentry/platform/ring0/pagetables/pagetables.go b/pkg/sentry/platform/ring0/pagetables/pagetables.go
index 87e88e97d..7f18ac296 100644
--- a/pkg/sentry/platform/ring0/pagetables/pagetables.go
+++ b/pkg/sentry/platform/ring0/pagetables/pagetables.go
@@ -86,6 +86,8 @@ func (*mapVisitor) requiresSplit() bool { return true }
//
// Precondition: addr & length must be page-aligned, their sum must not overflow.
//
+// +checkescape:hard,stack
+//
//go:nosplit
func (p *PageTables) Map(addr usermem.Addr, length uintptr, opts MapOpts, physical uintptr) bool {
if !opts.AccessType.Any() {
@@ -128,6 +130,8 @@ func (v *unmapVisitor) visit(start uintptr, pte *PTE, align uintptr) {
//
// Precondition: addr & length must be page-aligned.
//
+// +checkescape:hard,stack
+//
//go:nosplit
func (p *PageTables) Unmap(addr usermem.Addr, length uintptr) bool {
w := unmapWalker{
@@ -162,6 +166,8 @@ func (v *emptyVisitor) visit(start uintptr, pte *PTE, align uintptr) {
//
// Precondition: addr & length must be page-aligned.
//
+// +checkescape:hard,stack
+//
//go:nosplit
func (p *PageTables) IsEmpty(addr usermem.Addr, length uintptr) bool {
w := emptyWalker{
@@ -197,6 +203,8 @@ func (*lookupVisitor) requiresSplit() bool { return false }
// Lookup returns the physical address for the given virtual address.
//
+// +checkescape:hard,stack
+//
//go:nosplit
func (p *PageTables) Lookup(addr usermem.Addr) (physical uintptr, opts MapOpts) {
mask := uintptr(usermem.PageSize - 1)
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-01 23:45:19 +0000