Merge release-20200818.0-61-g983a55aa0 (automated)

31 files changed, 103 insertions, 96 deletions

diff --git a/pkg/sentry/arch/arch_abi_autogen_unsafe.go b/pkg/sentry/arch/arch_abi_autogen_unsafe.go
index 5d77cd2d1..9df95c6f9 100644
--- a/pkg/sentry/arch/arch_abi_autogen_unsafe.go
+++ b/pkg/sentry/arch/arch_abi_autogen_unsafe.go
@@ -98,7 +98,7 @@ func (s *SignalAct) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (i
     length, err := task.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
     // Since we bypassed the compiler's escape analysis, indicate that s
     // must live until the use above.
-    runtime.KeepAlive(s)
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
     return length, err
 }
 
@@ -131,7 +131,7 @@ func (s *SignalAct) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {
     length, err := task.CopyInBytes(addr, buf) // escapes: okay.
     // Since we bypassed the compiler's escape analysis, indicate that s
     // must live until the use above.
-    runtime.KeepAlive(s)
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
     return length, err
 }
 
@@ -155,7 +155,7 @@ func (s *SignalAct) WriteTo(writer io.Writer) (int64, error) {
     length, err := writer.Write(buf)
     // Since we bypassed the compiler's escape analysis, indicate that s
     // must live until the use above.
-    runtime.KeepAlive(s)
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
     return int64(length), err
 }
 
@@ -217,7 +217,7 @@ func (s *SignalStack) CopyOutN(task marshal.Task, addr usermem.Addr, limit int)
     length, err := task.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
     // Since we bypassed the compiler's escape analysis, indicate that s
     // must live until the use above.
-    runtime.KeepAlive(s)
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
     return length, err
 }
 
@@ -240,7 +240,7 @@ func (s *SignalStack) CopyIn(task marshal.Task, addr usermem.Addr) (int, error)
     length, err := task.CopyInBytes(addr, buf) // escapes: okay.
     // Since we bypassed the compiler's escape analysis, indicate that s
     // must live until the use above.
-    runtime.KeepAlive(s)
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
     return length, err
 }
 
@@ -256,7 +256,7 @@ func (s *SignalStack) WriteTo(writer io.Writer) (int64, error) {
     length, err := writer.Write(buf)
     // Since we bypassed the compiler's escape analysis, indicate that s
     // must live until the use above.
-    runtime.KeepAlive(s)
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
     return int64(length), err
 }
 
@@ -327,7 +327,7 @@ func (s *SignalInfo) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (
     length, err := task.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
     // Since we bypassed the compiler's escape analysis, indicate that s
     // must live until the use above.
-    runtime.KeepAlive(s)
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
     return length, err
 }
 
@@ -350,7 +350,7 @@ func (s *SignalInfo) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {
     length, err := task.CopyInBytes(addr, buf) // escapes: okay.
     // Since we bypassed the compiler's escape analysis, indicate that s
     // must live until the use above.
-    runtime.KeepAlive(s)
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
     return length, err
 }
 
@@ -366,7 +366,7 @@ func (s *SignalInfo) WriteTo(writer io.Writer) (int64, error) {
     length, err := writer.Write(buf)
     // Since we bypassed the compiler's escape analysis, indicate that s
     // must live until the use above.
-    runtime.KeepAlive(s)
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
     return int64(length), err
 }
 
diff --git a/pkg/sentry/fsimpl/devpts/root_inode_refs.go b/pkg/sentry/fsimpl/devpts/root_inode_refs.go
index 051801202..4abb66431 100644
--- a/pkg/sentry/fsimpl/devpts/root_inode_refs.go
+++ b/pkg/sentry/fsimpl/devpts/root_inode_refs.go
@@ -2,11 +2,10 @@ package devpts
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/fuse/inode_refs.go b/pkg/sentry/fsimpl/fuse/inode_refs.go
index 6b9456e1d..4fb4d4da7 100644
--- a/pkg/sentry/fsimpl/fuse/inode_refs.go
+++ b/pkg/sentry/fsimpl/fuse/inode_refs.go
@@ -2,11 +2,10 @@ package fuse
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/host/connected_endpoint_refs.go b/pkg/sentry/fsimpl/host/connected_endpoint_refs.go
index babb3f664..225f59782 100644
--- a/pkg/sentry/fsimpl/host/connected_endpoint_refs.go
+++ b/pkg/sentry/fsimpl/host/connected_endpoint_refs.go
@@ -2,11 +2,10 @@ package host
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/host/inode_refs.go b/pkg/sentry/fsimpl/host/inode_refs.go
index 17f90ce4a..4075eae17 100644
--- a/pkg/sentry/fsimpl/host/inode_refs.go
+++ b/pkg/sentry/fsimpl/host/inode_refs.go
@@ -2,11 +2,10 @@ package host
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/kernfs/dentry_refs.go b/pkg/sentry/fsimpl/kernfs/dentry_refs.go
index 79863b3bc..f99d4941a 100644
--- a/pkg/sentry/fsimpl/kernfs/dentry_refs.go
+++ b/pkg/sentry/fsimpl/kernfs/dentry_refs.go
@@ -2,11 +2,10 @@ package kernfs
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/kernfs/static_directory_refs.go b/pkg/sentry/fsimpl/kernfs/static_directory_refs.go
index 478b04bdd..2b258010e 100644
--- a/pkg/sentry/fsimpl/kernfs/static_directory_refs.go
+++ b/pkg/sentry/fsimpl/kernfs/static_directory_refs.go
@@ -2,11 +2,10 @@ package kernfs
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/proc/fd_dir_inode_refs.go b/pkg/sentry/fsimpl/proc/fd_dir_inode_refs.go
index 9431c1506..467c32752 100644
--- a/pkg/sentry/fsimpl/proc/fd_dir_inode_refs.go
+++ b/pkg/sentry/fsimpl/proc/fd_dir_inode_refs.go
@@ -2,11 +2,10 @@ package proc
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/proc/fd_info_dir_inode_refs.go b/pkg/sentry/fsimpl/proc/fd_info_dir_inode_refs.go
index 872b20eb0..3fcda0948 100644
--- a/pkg/sentry/fsimpl/proc/fd_info_dir_inode_refs.go
+++ b/pkg/sentry/fsimpl/proc/fd_info_dir_inode_refs.go
@@ -2,11 +2,10 @@ package proc
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/proc/subtasks_inode_refs.go b/pkg/sentry/fsimpl/proc/subtasks_inode_refs.go
index c6d9b3522..2da6801c2 100644
--- a/pkg/sentry/fsimpl/proc/subtasks_inode_refs.go
+++ b/pkg/sentry/fsimpl/proc/subtasks_inode_refs.go
@@ -2,11 +2,10 @@ package proc
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/proc/task_inode_refs.go b/pkg/sentry/fsimpl/proc/task_inode_refs.go
index 714488450..b6e19844c 100644
--- a/pkg/sentry/fsimpl/proc/task_inode_refs.go
+++ b/pkg/sentry/fsimpl/proc/task_inode_refs.go
@@ -2,11 +2,10 @@ package proc
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/proc/tasks_inode_refs.go b/pkg/sentry/fsimpl/proc/tasks_inode_refs.go
index 22d9cc488..6207364e4 100644
--- a/pkg/sentry/fsimpl/proc/tasks_inode_refs.go
+++ b/pkg/sentry/fsimpl/proc/tasks_inode_refs.go
@@ -2,11 +2,10 @@ package proc
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/sys/dir_refs.go b/pkg/sentry/fsimpl/sys/dir_refs.go
index 89609b198..9d15d4c80 100644
--- a/pkg/sentry/fsimpl/sys/dir_refs.go
+++ b/pkg/sentry/fsimpl/sys/dir_refs.go
@@ -2,11 +2,10 @@ package sys
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/tmpfs/inode_refs.go b/pkg/sentry/fsimpl/tmpfs/inode_refs.go
index dbf0b2766..ff5e99c52 100644
--- a/pkg/sentry/fsimpl/tmpfs/inode_refs.go
+++ b/pkg/sentry/fsimpl/tmpfs/inode_refs.go
@@ -2,11 +2,10 @@ package tmpfs
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/kernel/fd_table_refs.go b/pkg/sentry/kernel/fd_table_refs.go
index ecba138ac..a630289c9 100644
--- a/pkg/sentry/kernel/fd_table_refs.go
+++ b/pkg/sentry/kernel/fd_table_refs.go
@@ -2,11 +2,10 @@ package kernel
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/kernel/fs_context_refs.go b/pkg/sentry/kernel/fs_context_refs.go
index fb2fde971..e8bb1e6ee 100644
--- a/pkg/sentry/kernel/fs_context_refs.go
+++ b/pkg/sentry/kernel/fs_context_refs.go
@@ -2,11 +2,10 @@ package kernel
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/kernel/process_group_refs.go b/pkg/sentry/kernel/process_group_refs.go
index 4ed6e6458..4b257d548 100644
--- a/pkg/sentry/kernel/process_group_refs.go
+++ b/pkg/sentry/kernel/process_group_refs.go
@@ -2,11 +2,10 @@ package kernel
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/kernel/session_refs.go b/pkg/sentry/kernel/session_refs.go
index f2e1bb797..204fdd060 100644
--- a/pkg/sentry/kernel/session_refs.go
+++ b/pkg/sentry/kernel/session_refs.go
@@ -2,11 +2,10 @@ package kernel
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/kernel/shm/shm_refs.go b/pkg/sentry/kernel/shm/shm_refs.go
index 51e07d0b3..4bffdd0b3 100644
--- a/pkg/sentry/kernel/shm/shm_refs.go
+++ b/pkg/sentry/kernel/shm/shm_refs.go
@@ -2,11 +2,10 @@ package shm
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/mm/aio_mappable_refs.go b/pkg/sentry/mm/aio_mappable_refs.go
index b99909f07..141747137 100644
--- a/pkg/sentry/mm/aio_mappable_refs.go
+++ b/pkg/sentry/mm/aio_mappable_refs.go
@@ -2,11 +2,10 @@ package mm
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/mm/special_mappable_refs.go b/pkg/sentry/mm/special_mappable_refs.go
index 035bbe690..0921a5d18 100644
--- a/pkg/sentry/mm/special_mappable_refs.go
+++ b/pkg/sentry/mm/special_mappable_refs.go
@@ -2,11 +2,10 @@ package mm
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/platform/kvm/bluepill_fault.go b/pkg/sentry/platform/kvm/bluepill_fault.go
index e34f46aeb..a182e4f22 100644
--- a/pkg/sentry/platform/kvm/bluepill_fault.go
+++ b/pkg/sentry/platform/kvm/bluepill_fault.go
@@ -98,6 +98,10 @@ func handleBluepillFault(m *machine, physical uintptr, phyRegions []physicalRegi
 	}
 	errno := m.setMemoryRegion(int(slot), physicalStart, length, virtualStart, flags)
 	if errno == 0 {
+		// Store the physical address in the slot. This is used to
+		// avoid calls to handleBluepillFault in the future (see
+		// machine.mapPhysical).
+		atomic.StoreUintptr(&m.usedSlots[slot], physical)
 		// Successfully added region; we can increment nextSlot and
 		// allow another set to proceed here.
 		atomic.StoreUint32(&m.nextSlot, slot+1)
diff --git a/pkg/sentry/platform/kvm/kvm_const.go b/pkg/sentry/platform/kvm/kvm_const.go
index 3bf918446..5c4b18899 100644
--- a/pkg/sentry/platform/kvm/kvm_const.go
+++ b/pkg/sentry/platform/kvm/kvm_const.go
@@ -56,6 +56,7 @@ const (
 
 // KVM capability options.
 const (
+	_KVM_CAP_MAX_MEMSLOTS          = 0x0a
 	_KVM_CAP_MAX_VCPUS             = 0x42
 	_KVM_CAP_ARM_VM_IPA_SIZE       = 0xa5
 	_KVM_CAP_VCPU_EVENTS           = 0x29
@@ -64,6 +65,7 @@ const (
 
 // KVM limits.
 const (
+	_KVM_NR_MEMSLOTS      = 0x100
 	_KVM_NR_VCPUS         = 0xff
 	_KVM_NR_INTERRUPTS    = 0x100
 	_KVM_NR_CPUID_ENTRIES = 0x100
diff --git a/pkg/sentry/platform/kvm/machine.go b/pkg/sentry/platform/kvm/machine.go
index 6c54712d1..372a4cbd7 100644
--- a/pkg/sentry/platform/kvm/machine.go
+++ b/pkg/sentry/platform/kvm/machine.go
@@ -43,9 +43,6 @@ type machine struct {
 	// kernel is the set of global structures.
 	kernel ring0.Kernel
 
-	// mappingCache is used for mapPhysical.
-	mappingCache sync.Map
-
 	// mu protects vCPUs.
 	mu sync.RWMutex
 
@@ -63,6 +60,12 @@ type machine struct {
 	// maxVCPUs is the maximum number of vCPUs supported by the machine.
 	maxVCPUs int
 
+	// maxSlots is the maximum number of memory slots supported by the machine.
+	maxSlots int
+
+	// usedSlots is the set of used physical addresses (sorted).
+	usedSlots []uintptr
+
 	// nextID is the next vCPU ID.
 	nextID uint32
 }
@@ -184,6 +187,7 @@ func newMachine(vm int) (*machine, error) {
 		PageTables: pagetables.New(newAllocator()),
 	})
 
+	// Pull the maximum vCPUs.
 	maxVCPUs, _, errno := syscall.RawSyscall(syscall.SYS_IOCTL, uintptr(m.fd), _KVM_CHECK_EXTENSION, _KVM_CAP_MAX_VCPUS)
 	if errno != 0 {
 		m.maxVCPUs = _KVM_NR_VCPUS
@@ -191,11 +195,19 @@ func newMachine(vm int) (*machine, error) {
 		m.maxVCPUs = int(maxVCPUs)
 	}
 	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)
 
+	// Pull the maximum slots.
+	maxSlots, _, errno := syscall.RawSyscall(syscall.SYS_IOCTL, uintptr(m.fd), _KVM_CHECK_EXTENSION, _KVM_CAP_MAX_MEMSLOTS)
+	if errno != 0 {
+		m.maxSlots = _KVM_NR_MEMSLOTS
+	} else {
+		m.maxSlots = int(maxSlots)
+	}
+	log.Debugf("The maximum number of slots is %d.", m.maxSlots)
+	m.usedSlots = make([]uintptr, m.maxSlots)
+
 	// 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.
@@ -272,6 +284,20 @@ func newMachine(vm int) (*machine, error) {
 	return m, nil
 }
 
+// hasSlot returns true iff the given address is mapped.
+//
+// This must be done via a linear scan.
+//
+//go:nosplit
+func (m *machine) hasSlot(physical uintptr) bool {
+	for i := 0; i < len(m.usedSlots); i++ {
+		if p := atomic.LoadUintptr(&m.usedSlots[i]); p == physical {
+			return true
+		}
+	}
+	return false
+}
+
 // mapPhysical checks for the mapping of a physical range, and installs one if
 // not available. This attempts to be efficient for calls in the hot path.
 //
@@ -286,8 +312,8 @@ func (m *machine) mapPhysical(physical, length uintptr, phyRegions []physicalReg
 			panic("mapPhysical on unknown physical address")
 		}
 
-		if _, ok := m.mappingCache.LoadOrStore(physicalStart, true); !ok {
-			// Not present in the cache; requires setting the slot.
+		// Is this already mapped? Check the usedSlots.
+		if !m.hasSlot(physicalStart) {
 			if _, ok := handleBluepillFault(m, physical, phyRegions, flags); !ok {
 				panic("handleBluepillFault failed")
 			}
diff --git a/pkg/sentry/platform/ring0/defs_impl_arm64.go b/pkg/sentry/platform/ring0/defs_impl_arm64.go
index eba2eac30..424b66f76 100644
--- a/pkg/sentry/platform/ring0/defs_impl_arm64.go
+++ b/pkg/sentry/platform/ring0/defs_impl_arm64.go
@@ -3,11 +3,11 @@ package ring0
 import (
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
-	"io"
-	"reflect"
 
 	"fmt"
 	"gvisor.dev/gvisor/pkg/usermem"
+	"io"
+	"reflect"
 )
 
 // Useful bits.
diff --git a/pkg/sentry/socket/unix/socket_refs.go b/pkg/sentry/socket/unix/socket_refs.go
index dababb85f..39aaedc7f 100644
--- a/pkg/sentry/socket/unix/socket_refs.go
+++ b/pkg/sentry/socket/unix/socket_refs.go
@@ -2,11 +2,10 @@ package unix
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/socket/unix/transport/queue_refs.go b/pkg/sentry/socket/unix/transport/queue_refs.go
index 0d4e34988..4c3dcd13f 100644
--- a/pkg/sentry/socket/unix/transport/queue_refs.go
+++ b/pkg/sentry/socket/unix/transport/queue_refs.go
@@ -2,11 +2,10 @@ package transport
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/syscalls/linux/vfs2/vfs2_abi_autogen_unsafe.go b/pkg/sentry/syscalls/linux/vfs2/vfs2_abi_autogen_unsafe.go
index ed5e48eaa..da2b37bba 100644
--- a/pkg/sentry/syscalls/linux/vfs2/vfs2_abi_autogen_unsafe.go
+++ b/pkg/sentry/syscalls/linux/vfs2/vfs2_abi_autogen_unsafe.go
@@ -66,7 +66,7 @@ func (s *sigSetWithSize) CopyOutN(task marshal.Task, addr usermem.Addr, limit in
     length, err := task.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
     // Since we bypassed the compiler's escape analysis, indicate that s
     // must live until the use above.
-    runtime.KeepAlive(s)
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
     return length, err
 }
 
@@ -89,7 +89,7 @@ func (s *sigSetWithSize) CopyIn(task marshal.Task, addr usermem.Addr) (int, erro
     length, err := task.CopyInBytes(addr, buf) // escapes: okay.
     // Since we bypassed the compiler's escape analysis, indicate that s
     // must live until the use above.
-    runtime.KeepAlive(s)
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
     return length, err
 }
 
@@ -105,7 +105,7 @@ func (s *sigSetWithSize) WriteTo(writer io.Writer) (int64, error) {
     length, err := writer.Write(buf)
     // Since we bypassed the compiler's escape analysis, indicate that s
     // must live until the use above.
-    runtime.KeepAlive(s)
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
     return int64(length), err
 }
 
diff --git a/pkg/sentry/vfs/file_description_refs.go b/pkg/sentry/vfs/file_description_refs.go
index bdd7e6554..6c7747259 100644
--- a/pkg/sentry/vfs/file_description_refs.go
+++ b/pkg/sentry/vfs/file_description_refs.go
@@ -2,11 +2,10 @@ package vfs
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/vfs/filesystem_refs.go b/pkg/sentry/vfs/filesystem_refs.go
index 38a9a986f..96f681831 100644
--- a/pkg/sentry/vfs/filesystem_refs.go
+++ b/pkg/sentry/vfs/filesystem_refs.go
@@ -2,11 +2,10 @@ package vfs
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/vfs/mount_namespace_refs.go b/pkg/sentry/vfs/mount_namespace_refs.go
index 63285fb8e..4c422c81f 100644
--- a/pkg/sentry/vfs/mount_namespace_refs.go
+++ b/pkg/sentry/vfs/mount_namespace_refs.go
@@ -2,11 +2,10 @@ package vfs
 
 import (
 	"fmt"
-	"runtime"
-	"sync/atomic"
-
 	"gvisor.dev/gvisor/pkg/log"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
+	"runtime"
+	"sync/atomic"
 )
 
 // ownerType is used to customize logging. Note that we use a pointer to T so