summaryrefslogtreecommitdiffhomepage
path: root/pkg
diff options
context:
space:
mode:
Diffstat (limited to 'pkg')
-rw-r--r--pkg/sentry/arch/arch_aarch64.go23
-rw-r--r--pkg/sentry/arch/arch_amd64.go4
-rw-r--r--pkg/sentry/arch/arch_arm64.go4
-rw-r--r--pkg/sentry/arch/arch_x86.go16
-rw-r--r--pkg/sentry/kernel/BUILD1
-rw-r--r--pkg/sentry/kernel/task.go15
-rw-r--r--pkg/sentry/kernel/task_run.go17
-rw-r--r--pkg/sentry/kernel/task_work.go38
-rw-r--r--pkg/sentry/platform/ring0/kernel_arm64.go6
-rw-r--r--pkg/tcpip/stack/iptables.go93
10 files changed, 140 insertions, 77 deletions
diff --git a/pkg/sentry/arch/arch_aarch64.go b/pkg/sentry/arch/arch_aarch64.go
index daba8b172..fd95eb2d2 100644
--- a/pkg/sentry/arch/arch_aarch64.go
+++ b/pkg/sentry/arch/arch_aarch64.go
@@ -28,7 +28,14 @@ import (
)
// Registers represents the CPU registers for this architecture.
-type Registers = linux.PtraceRegs
+//
+// +stateify savable
+type Registers struct {
+ linux.PtraceRegs
+
+ // TPIDR_EL0 is the EL0 Read/Write Software Thread ID Register.
+ TPIDR_EL0 uint64
+}
const (
// SyscallWidth is the width of insturctions.
@@ -101,9 +108,6 @@ type State struct {
// Our floating point state.
aarch64FPState `state:"wait"`
- // TLS pointer
- TPValue uint64
-
// FeatureSet is a pointer to the currently active feature set.
FeatureSet *cpuid.FeatureSet
@@ -157,7 +161,6 @@ func (s *State) Fork() State {
return State{
Regs: s.Regs,
aarch64FPState: s.aarch64FPState.fork(),
- TPValue: s.TPValue,
FeatureSet: s.FeatureSet,
OrigR0: s.OrigR0,
}
@@ -241,18 +244,18 @@ func (s *State) ptraceGetRegs() Registers {
return s.Regs
}
-var registersSize = (*Registers)(nil).SizeBytes()
+var ptraceRegistersSize = (*linux.PtraceRegs)(nil).SizeBytes()
// PtraceSetRegs implements Context.PtraceSetRegs.
func (s *State) PtraceSetRegs(src io.Reader) (int, error) {
var regs Registers
- buf := make([]byte, registersSize)
+ buf := make([]byte, ptraceRegistersSize)
if _, err := io.ReadFull(src, buf); err != nil {
return 0, err
}
regs.UnmarshalUnsafe(buf)
s.Regs = regs
- return registersSize, nil
+ return ptraceRegistersSize, nil
}
// PtraceGetFPRegs implements Context.PtraceGetFPRegs.
@@ -278,7 +281,7 @@ const (
func (s *State) PtraceGetRegSet(regset uintptr, dst io.Writer, maxlen int) (int, error) {
switch regset {
case _NT_PRSTATUS:
- if maxlen < registersSize {
+ if maxlen < ptraceRegistersSize {
return 0, syserror.EFAULT
}
return s.PtraceGetRegs(dst)
@@ -291,7 +294,7 @@ func (s *State) PtraceGetRegSet(regset uintptr, dst io.Writer, maxlen int) (int,
func (s *State) PtraceSetRegSet(regset uintptr, src io.Reader, maxlen int) (int, error) {
switch regset {
case _NT_PRSTATUS:
- if maxlen < registersSize {
+ if maxlen < ptraceRegistersSize {
return 0, syserror.EFAULT
}
return s.PtraceSetRegs(src)
diff --git a/pkg/sentry/arch/arch_amd64.go b/pkg/sentry/arch/arch_amd64.go
index 3b3a0a272..1c3e3c14c 100644
--- a/pkg/sentry/arch/arch_amd64.go
+++ b/pkg/sentry/arch/arch_amd64.go
@@ -300,7 +300,7 @@ func (c *context64) PtracePeekUser(addr uintptr) (interface{}, error) {
// PTRACE_PEEKUSER and PTRACE_POKEUSER are only effective on regs and
// u_debugreg, returning 0 or silently no-oping for other fields
// respectively.
- if addr < uintptr(registersSize) {
+ if addr < uintptr(ptraceRegistersSize) {
regs := c.ptraceGetRegs()
buf := make([]byte, regs.SizeBytes())
regs.MarshalUnsafe(buf)
@@ -315,7 +315,7 @@ func (c *context64) PtracePokeUser(addr, data uintptr) error {
if addr&7 != 0 || addr >= userStructSize {
return syscall.EIO
}
- if addr < uintptr(registersSize) {
+ if addr < uintptr(ptraceRegistersSize) {
regs := c.ptraceGetRegs()
buf := make([]byte, regs.SizeBytes())
regs.MarshalUnsafe(buf)
diff --git a/pkg/sentry/arch/arch_arm64.go b/pkg/sentry/arch/arch_arm64.go
index ada7ac7b8..cabbf60e0 100644
--- a/pkg/sentry/arch/arch_arm64.go
+++ b/pkg/sentry/arch/arch_arm64.go
@@ -142,7 +142,7 @@ func (c *context64) SetStack(value uintptr) {
// TLS returns the current TLS pointer.
func (c *context64) TLS() uintptr {
- return uintptr(c.TPValue)
+ return uintptr(c.Regs.TPIDR_EL0)
}
// SetTLS sets the current TLS pointer. Returns false if value is invalid.
@@ -151,7 +151,7 @@ func (c *context64) SetTLS(value uintptr) bool {
return false
}
- c.TPValue = uint64(value)
+ c.Regs.TPIDR_EL0 = uint64(value)
return true
}
diff --git a/pkg/sentry/arch/arch_x86.go b/pkg/sentry/arch/arch_x86.go
index dc458b37f..b9405b320 100644
--- a/pkg/sentry/arch/arch_x86.go
+++ b/pkg/sentry/arch/arch_x86.go
@@ -31,7 +31,11 @@ import (
)
// Registers represents the CPU registers for this architecture.
-type Registers = linux.PtraceRegs
+//
+// +stateify savable
+type Registers struct {
+ linux.PtraceRegs
+}
// System-related constants for x86.
const (
@@ -311,12 +315,12 @@ func (s *State) ptraceGetRegs() Registers {
return regs
}
-var registersSize = (*Registers)(nil).SizeBytes()
+var ptraceRegistersSize = (*linux.PtraceRegs)(nil).SizeBytes()
// PtraceSetRegs implements Context.PtraceSetRegs.
func (s *State) PtraceSetRegs(src io.Reader) (int, error) {
var regs Registers
- buf := make([]byte, registersSize)
+ buf := make([]byte, ptraceRegistersSize)
if _, err := io.ReadFull(src, buf); err != nil {
return 0, err
}
@@ -374,7 +378,7 @@ func (s *State) PtraceSetRegs(src io.Reader) (int, error) {
}
regs.Eflags = (s.Regs.Eflags &^ eflagsPtraceMutable) | (regs.Eflags & eflagsPtraceMutable)
s.Regs = regs
- return registersSize, nil
+ return ptraceRegistersSize, nil
}
// isUserSegmentSelector returns true if the given segment selector specifies a
@@ -543,7 +547,7 @@ const (
func (s *State) PtraceGetRegSet(regset uintptr, dst io.Writer, maxlen int) (int, error) {
switch regset {
case _NT_PRSTATUS:
- if maxlen < registersSize {
+ if maxlen < ptraceRegistersSize {
return 0, syserror.EFAULT
}
return s.PtraceGetRegs(dst)
@@ -563,7 +567,7 @@ func (s *State) PtraceGetRegSet(regset uintptr, dst io.Writer, maxlen int) (int,
func (s *State) PtraceSetRegSet(regset uintptr, src io.Reader, maxlen int) (int, error) {
switch regset {
case _NT_PRSTATUS:
- if maxlen < registersSize {
+ if maxlen < ptraceRegistersSize {
return 0, syserror.EFAULT
}
return s.PtraceSetRegs(src)
diff --git a/pkg/sentry/kernel/BUILD b/pkg/sentry/kernel/BUILD
index 25fe1921b..f6886a758 100644
--- a/pkg/sentry/kernel/BUILD
+++ b/pkg/sentry/kernel/BUILD
@@ -132,6 +132,7 @@ go_library(
"task_stop.go",
"task_syscall.go",
"task_usermem.go",
+ "task_work.go",
"thread_group.go",
"threads.go",
"timekeeper.go",
diff --git a/pkg/sentry/kernel/task.go b/pkg/sentry/kernel/task.go
index f48247c94..b3d655b6e 100644
--- a/pkg/sentry/kernel/task.go
+++ b/pkg/sentry/kernel/task.go
@@ -68,6 +68,21 @@ type Task struct {
// runState is exclusive to the task goroutine.
runState taskRunState
+ // taskWorkCount represents the current size of the task work queue. It is
+ // used to avoid acquiring taskWorkMu when the queue is empty.
+ //
+ // Must accessed with atomic memory operations.
+ taskWorkCount int32
+
+ // taskWorkMu protects taskWork.
+ taskWorkMu sync.Mutex `state:"nosave"`
+
+ // taskWork is a queue of work to be executed before resuming user execution.
+ // It is similar to the task_work mechanism in Linux.
+ //
+ // taskWork is exclusive to the task goroutine.
+ taskWork []TaskWorker
+
// haveSyscallReturn is true if tc.Arch().Return() represents a value
// returned by a syscall (or set by ptrace after a syscall).
//
diff --git a/pkg/sentry/kernel/task_run.go b/pkg/sentry/kernel/task_run.go
index d654dd997..7d4f44caf 100644
--- a/pkg/sentry/kernel/task_run.go
+++ b/pkg/sentry/kernel/task_run.go
@@ -167,7 +167,22 @@ func (app *runApp) execute(t *Task) taskRunState {
return (*runInterrupt)(nil)
}
- // We're about to switch to the application again. If there's still a
+ // Execute any task work callbacks before returning to user space.
+ if atomic.LoadInt32(&t.taskWorkCount) > 0 {
+ t.taskWorkMu.Lock()
+ queue := t.taskWork
+ t.taskWork = nil
+ atomic.StoreInt32(&t.taskWorkCount, 0)
+ t.taskWorkMu.Unlock()
+
+ // Do not hold taskWorkMu while executing task work, which may register
+ // more work.
+ for _, work := range queue {
+ work.TaskWork(t)
+ }
+ }
+
+ // We're about to switch to the application again. If there's still an
// unhandled SyscallRestartErrno that wasn't translated to an EINTR,
// restart the syscall that was interrupted. If there's a saved signal
// mask, restore it. (Note that restoring the saved signal mask may unblock
diff --git a/pkg/sentry/kernel/task_work.go b/pkg/sentry/kernel/task_work.go
new file mode 100644
index 000000000..dda5a433a
--- /dev/null
+++ b/pkg/sentry/kernel/task_work.go
@@ -0,0 +1,38 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package kernel
+
+import "sync/atomic"
+
+// TaskWorker is a deferred task.
+//
+// This must be savable.
+type TaskWorker interface {
+ // TaskWork will be executed prior to returning to user space. Note that
+ // TaskWork may call RegisterWork again, but this will not be executed until
+ // the next return to user space, unlike in Linux. This effectively allows
+ // registration of indefinite user return hooks, but not by default.
+ TaskWork(t *Task)
+}
+
+// RegisterWork can be used to register additional task work that will be
+// performed prior to returning to user space. See TaskWorker.TaskWork for
+// semantics regarding registration.
+func (t *Task) RegisterWork(work TaskWorker) {
+ t.taskWorkMu.Lock()
+ defer t.taskWorkMu.Unlock()
+ atomic.AddInt32(&t.taskWorkCount, 1)
+ t.taskWork = append(t.taskWork, work)
+}
diff --git a/pkg/sentry/platform/ring0/kernel_arm64.go b/pkg/sentry/platform/ring0/kernel_arm64.go
index ccacaea6b..fca3a5478 100644
--- a/pkg/sentry/platform/ring0/kernel_arm64.go
+++ b/pkg/sentry/platform/ring0/kernel_arm64.go
@@ -58,7 +58,13 @@ func (c *CPU) SwitchToUser(switchOpts SwitchOpts) (vector Vector) {
regs.Pstate &= ^uint64(UserFlagsClear)
regs.Pstate |= UserFlagsSet
+
+ SetTLS(regs.TPIDR_EL0)
+
kernelExitToEl0()
+
+ regs.TPIDR_EL0 = GetTLS()
+
vector = c.vecCode
// Perform the switch.
diff --git a/pkg/tcpip/stack/iptables.go b/pkg/tcpip/stack/iptables.go
index ca1dda695..cbbae4224 100644
--- a/pkg/tcpip/stack/iptables.go
+++ b/pkg/tcpip/stack/iptables.go
@@ -58,8 +58,7 @@ const reaperDelay = 5 * time.Second
func DefaultTables() *IPTables {
return &IPTables{
tables: [numTables]Table{
- // NAT table.
- Table{
+ natID: Table{
Rules: []Rule{
Rule{Target: AcceptTarget{}},
Rule{Target: AcceptTarget{}},
@@ -68,22 +67,21 @@ func DefaultTables() *IPTables {
Rule{Target: ErrorTarget{}},
},
BuiltinChains: [NumHooks]int{
- 0, // Prerouting.
- 1, // Input.
- HookUnset, // Forward.
- 2, // Output.
- 3, // Postrouting.
+ Prerouting: 0,
+ Input: 1,
+ Forward: HookUnset,
+ Output: 2,
+ Postrouting: 3,
},
Underflows: [NumHooks]int{
- 0, // Prerouting.
- 1, // Input.
- HookUnset, // Forward.
- 2, // Output.
- 3, // Postrouting.
+ Prerouting: 0,
+ Input: 1,
+ Forward: HookUnset,
+ Output: 2,
+ Postrouting: 3,
},
},
- // Mangle table.
- Table{
+ mangleID: Table{
Rules: []Rule{
Rule{Target: AcceptTarget{}},
Rule{Target: AcceptTarget{}},
@@ -94,15 +92,14 @@ func DefaultTables() *IPTables {
Output: 1,
},
Underflows: [NumHooks]int{
- 0, // Prerouting.
- HookUnset, // Input.
- HookUnset, // Forward.
- 1, // Output.
- HookUnset, // Postrouting.
+ Prerouting: 0,
+ Input: HookUnset,
+ Forward: HookUnset,
+ Output: 1,
+ Postrouting: HookUnset,
},
},
- // Filter table.
- Table{
+ filterID: Table{
Rules: []Rule{
Rule{Target: AcceptTarget{}},
Rule{Target: AcceptTarget{}},
@@ -110,27 +107,25 @@ func DefaultTables() *IPTables {
Rule{Target: ErrorTarget{}},
},
BuiltinChains: [NumHooks]int{
- HookUnset, // Prerouting.
- Input: 0, // Input.
- Forward: 1, // Forward.
- Output: 2, // Output.
- HookUnset, // Postrouting.
+ Prerouting: HookUnset,
+ Input: 0,
+ Forward: 1,
+ Output: 2,
+ Postrouting: HookUnset,
},
Underflows: [NumHooks]int{
- HookUnset, // Prerouting.
- 0, // Input.
- 1, // Forward.
- 2, // Output.
- HookUnset, // Postrouting.
+ Prerouting: HookUnset,
+ Input: 0,
+ Forward: 1,
+ Output: 2,
+ Postrouting: HookUnset,
},
},
},
priorities: [NumHooks][]tableID{
- []tableID{mangleID, natID}, // Prerouting.
- []tableID{natID, filterID}, // Input.
- []tableID{}, // Forward.
- []tableID{mangleID, natID, filterID}, // Output.
- []tableID{}, // Postrouting.
+ Prerouting: []tableID{mangleID, natID},
+ Input: []tableID{natID, filterID},
+ Output: []tableID{mangleID, natID, filterID},
},
connections: ConnTrack{
seed: generateRandUint32(),
@@ -145,18 +140,12 @@ func EmptyFilterTable() Table {
return Table{
Rules: []Rule{},
BuiltinChains: [NumHooks]int{
- HookUnset,
- 0,
- 0,
- 0,
- HookUnset,
+ Prerouting: HookUnset,
+ Postrouting: HookUnset,
},
Underflows: [NumHooks]int{
- HookUnset,
- 0,
- 0,
- 0,
- HookUnset,
+ Prerouting: HookUnset,
+ Postrouting: HookUnset,
},
}
}
@@ -167,18 +156,10 @@ func EmptyNATTable() Table {
return Table{
Rules: []Rule{},
BuiltinChains: [NumHooks]int{
- 0,
- 0,
- HookUnset,
- 0,
- 0,
+ Forward: HookUnset,
},
Underflows: [NumHooks]int{
- 0,
- 0,
- HookUnset,
- 0,
- 0,
+ Forward: HookUnset,
},
}
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 14:34:03 +0000