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-rw-r--r--pkg/sentry/kernel/kernel.go4
-rw-r--r--pkg/sentry/kernel/pipe/BUILD18
-rw-r--r--pkg/sentry/kernel/pipe/buffer.go115
-rw-r--r--pkg/sentry/kernel/pipe/buffer_test.go32
-rw-r--r--pkg/sentry/kernel/pipe/pipe.go118
-rw-r--r--pkg/sentry/kernel/pipe/pipe_util.go25
-rw-r--r--pkg/sentry/kernel/task_run.go41
7 files changed, 67 insertions, 286 deletions
diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go
index 8b76750e9..1d627564f 100644
--- a/pkg/sentry/kernel/kernel.go
+++ b/pkg/sentry/kernel/kernel.go
@@ -755,6 +755,8 @@ func (ctx *createProcessContext) Value(key interface{}) interface{} {
return ctx.k.GlobalInit().Leader().MountNamespaceVFS2()
case fs.CtxDirentCacheLimiter:
return ctx.k.DirentCacheLimiter
+ case inet.CtxStack:
+ return ctx.k.RootNetworkNamespace().Stack()
case ktime.CtxRealtimeClock:
return ctx.k.RealtimeClock()
case limits.CtxLimits:
@@ -1481,6 +1483,8 @@ func (ctx supervisorContext) Value(key interface{}) interface{} {
return ctx.k.GlobalInit().Leader().MountNamespaceVFS2()
case fs.CtxDirentCacheLimiter:
return ctx.k.DirentCacheLimiter
+ case inet.CtxStack:
+ return ctx.k.RootNetworkNamespace().Stack()
case ktime.CtxRealtimeClock:
return ctx.k.RealtimeClock()
case limits.CtxLimits:
diff --git a/pkg/sentry/kernel/pipe/BUILD b/pkg/sentry/kernel/pipe/BUILD
index 4c049d5b4..f29dc0472 100644
--- a/pkg/sentry/kernel/pipe/BUILD
+++ b/pkg/sentry/kernel/pipe/BUILD
@@ -1,25 +1,10 @@
load("//tools:defs.bzl", "go_library", "go_test")
-load("//tools/go_generics:defs.bzl", "go_template_instance")
package(licenses = ["notice"])
-go_template_instance(
- name = "buffer_list",
- out = "buffer_list.go",
- package = "pipe",
- prefix = "buffer",
- template = "//pkg/ilist:generic_list",
- types = {
- "Element": "*buffer",
- "Linker": "*buffer",
- },
-)
-
go_library(
name = "pipe",
srcs = [
- "buffer.go",
- "buffer_list.go",
"device.go",
"node.go",
"pipe.go",
@@ -33,8 +18,8 @@ go_library(
deps = [
"//pkg/abi/linux",
"//pkg/amutex",
+ "//pkg/buffer",
"//pkg/context",
- "//pkg/safemem",
"//pkg/sentry/arch",
"//pkg/sentry/device",
"//pkg/sentry/fs",
@@ -51,7 +36,6 @@ go_test(
name = "pipe_test",
size = "small",
srcs = [
- "buffer_test.go",
"node_test.go",
"pipe_test.go",
],
diff --git a/pkg/sentry/kernel/pipe/buffer.go b/pkg/sentry/kernel/pipe/buffer.go
deleted file mode 100644
index fe3be5dbd..000000000
--- a/pkg/sentry/kernel/pipe/buffer.go
+++ /dev/null
@@ -1,115 +0,0 @@
-// Copyright 2018 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 pipe
-
-import (
- "io"
-
- "gvisor.dev/gvisor/pkg/safemem"
- "gvisor.dev/gvisor/pkg/sync"
-)
-
-// buffer encapsulates a queueable byte buffer.
-//
-// Note that the total size is slightly less than two pages. This
-// is done intentionally to ensure that the buffer object aligns
-// with runtime internals. We have no hard size or alignment
-// requirements. This two page size will effectively minimize
-// internal fragmentation, but still have a large enough chunk
-// to limit excessive segmentation.
-//
-// +stateify savable
-type buffer struct {
- data [8144]byte
- read int
- write int
- bufferEntry
-}
-
-// Reset resets internal data.
-//
-// This must be called before use.
-func (b *buffer) Reset() {
- b.read = 0
- b.write = 0
-}
-
-// Empty indicates the buffer is empty.
-//
-// This indicates there is no data left to read.
-func (b *buffer) Empty() bool {
- return b.read == b.write
-}
-
-// Full indicates the buffer is full.
-//
-// This indicates there is no capacity left to write.
-func (b *buffer) Full() bool {
- return b.write == len(b.data)
-}
-
-// WriteFromBlocks implements safemem.Writer.WriteFromBlocks.
-func (b *buffer) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error) {
- dst := safemem.BlockSeqOf(safemem.BlockFromSafeSlice(b.data[b.write:]))
- n, err := safemem.CopySeq(dst, srcs)
- b.write += int(n)
- return n, err
-}
-
-// WriteFromReader writes to the buffer from an io.Reader.
-func (b *buffer) WriteFromReader(r io.Reader, count int64) (int64, error) {
- dst := b.data[b.write:]
- if count < int64(len(dst)) {
- dst = b.data[b.write:][:count]
- }
- n, err := r.Read(dst)
- b.write += n
- return int64(n), err
-}
-
-// ReadToBlocks implements safemem.Reader.ReadToBlocks.
-func (b *buffer) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) {
- src := safemem.BlockSeqOf(safemem.BlockFromSafeSlice(b.data[b.read:b.write]))
- n, err := safemem.CopySeq(dsts, src)
- b.read += int(n)
- return n, err
-}
-
-// ReadToWriter reads from the buffer into an io.Writer.
-func (b *buffer) ReadToWriter(w io.Writer, count int64, dup bool) (int64, error) {
- src := b.data[b.read:b.write]
- if count < int64(len(src)) {
- src = b.data[b.read:][:count]
- }
- n, err := w.Write(src)
- if !dup {
- b.read += n
- }
- return int64(n), err
-}
-
-// bufferPool is a pool for buffers.
-var bufferPool = sync.Pool{
- New: func() interface{} {
- return new(buffer)
- },
-}
-
-// newBuffer grabs a new buffer from the pool.
-func newBuffer() *buffer {
- b := bufferPool.Get().(*buffer)
- b.Reset()
- return b
-}
diff --git a/pkg/sentry/kernel/pipe/buffer_test.go b/pkg/sentry/kernel/pipe/buffer_test.go
deleted file mode 100644
index 4d54b8b8f..000000000
--- a/pkg/sentry/kernel/pipe/buffer_test.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Copyright 2019 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 pipe
-
-import (
- "testing"
- "unsafe"
-
- "gvisor.dev/gvisor/pkg/usermem"
-)
-
-func TestBufferSize(t *testing.T) {
- bufferSize := unsafe.Sizeof(buffer{})
- if bufferSize < usermem.PageSize {
- t.Errorf("buffer is less than a page")
- }
- if bufferSize > (2 * usermem.PageSize) {
- t.Errorf("buffer is greater than two pages")
- }
-}
diff --git a/pkg/sentry/kernel/pipe/pipe.go b/pkg/sentry/kernel/pipe/pipe.go
index 08410283f..725e9db7d 100644
--- a/pkg/sentry/kernel/pipe/pipe.go
+++ b/pkg/sentry/kernel/pipe/pipe.go
@@ -20,6 +20,7 @@ import (
"sync/atomic"
"syscall"
+ "gvisor.dev/gvisor/pkg/buffer"
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sync"
@@ -70,10 +71,10 @@ type Pipe struct {
// mu protects all pipe internal state below.
mu sync.Mutex `state:"nosave"`
- // data is the buffer queue of pipe contents.
+ // view is the underlying set of buffers.
//
// This is protected by mu.
- data bufferList
+ view buffer.View
// max is the maximum size of the pipe in bytes. When this max has been
// reached, writers will get EWOULDBLOCK.
@@ -81,11 +82,6 @@ type Pipe struct {
// This is protected by mu.
max int64
- // size is the current size of the pipe in bytes.
- //
- // This is protected by mu.
- size int64
-
// hadWriter indicates if this pipe ever had a writer. Note that this
// does not necessarily indicate there is *currently* a writer, just
// that there has been a writer at some point since the pipe was
@@ -196,7 +192,7 @@ type readOps struct {
limit func(int64)
// read performs the actual read operation.
- read func(*buffer) (int64, error)
+ read func(*buffer.View) (int64, error)
}
// read reads data from the pipe into dst and returns the number of bytes
@@ -213,7 +209,7 @@ func (p *Pipe) read(ctx context.Context, ops readOps) (int64, error) {
defer p.mu.Unlock()
// Is the pipe empty?
- if p.size == 0 {
+ if p.view.Size() == 0 {
if !p.HasWriters() {
// There are no writers, return EOF.
return 0, nil
@@ -222,71 +218,13 @@ func (p *Pipe) read(ctx context.Context, ops readOps) (int64, error) {
}
// Limit how much we consume.
- if ops.left() > p.size {
- ops.limit(p.size)
+ if ops.left() > p.view.Size() {
+ ops.limit(p.view.Size())
}
- done := int64(0)
- for ops.left() > 0 {
- // Pop the first buffer.
- first := p.data.Front()
- if first == nil {
- break
- }
-
- // Copy user data.
- n, err := ops.read(first)
- done += int64(n)
- p.size -= n
-
- // Empty buffer?
- if first.Empty() {
- // Push to the free list.
- p.data.Remove(first)
- bufferPool.Put(first)
- }
-
- // Handle errors.
- if err != nil {
- return done, err
- }
- }
-
- return done, nil
-}
-
-// dup duplicates all data from this pipe into the given writer.
-//
-// There is no blocking behavior implemented here. The writer may propagate
-// some blocking error. All the writes must be complete writes.
-func (p *Pipe) dup(ctx context.Context, ops readOps) (int64, error) {
- p.mu.Lock()
- defer p.mu.Unlock()
-
- // Is the pipe empty?
- if p.size == 0 {
- if !p.HasWriters() {
- // See above.
- return 0, nil
- }
- return 0, syserror.ErrWouldBlock
- }
-
- // Limit how much we consume.
- if ops.left() > p.size {
- ops.limit(p.size)
- }
-
- done := int64(0)
- for buf := p.data.Front(); buf != nil; buf = buf.Next() {
- n, err := ops.read(buf)
- done += n
- if err != nil {
- return done, err
- }
- }
-
- return done, nil
+ // Copy user data; the read op is responsible for trimming.
+ done, err := ops.read(&p.view)
+ return done, err
}
type writeOps struct {
@@ -297,7 +235,7 @@ type writeOps struct {
limit func(int64)
// write should write to the provided buffer.
- write func(*buffer) (int64, error)
+ write func(*buffer.View) (int64, error)
}
// write writes data from sv into the pipe and returns the number of bytes
@@ -317,33 +255,19 @@ func (p *Pipe) write(ctx context.Context, ops writeOps) (int64, error) {
// POSIX requires that a write smaller than atomicIOBytes (PIPE_BUF) be
// atomic, but requires no atomicity for writes larger than this.
wanted := ops.left()
- if avail := p.max - p.size; wanted > avail {
+ if avail := p.max - p.view.Size(); wanted > avail {
if wanted <= p.atomicIOBytes {
return 0, syserror.ErrWouldBlock
}
ops.limit(avail)
}
- done := int64(0)
- for ops.left() > 0 {
- // Need a new buffer?
- last := p.data.Back()
- if last == nil || last.Full() {
- // Add a new buffer to the data list.
- last = newBuffer()
- p.data.PushBack(last)
- }
-
- // Copy user data.
- n, err := ops.write(last)
- done += int64(n)
- p.size += n
-
- // Handle errors.
- if err != nil {
- return done, err
- }
+ // Copy user data.
+ done, err := ops.write(&p.view)
+ if err != nil {
+ return done, err
}
+
if wanted > done {
// Partial write due to full pipe.
return done, syserror.ErrWouldBlock
@@ -396,7 +320,7 @@ func (p *Pipe) HasWriters() bool {
// Precondition: mu must be held.
func (p *Pipe) rReadinessLocked() waiter.EventMask {
ready := waiter.EventMask(0)
- if p.HasReaders() && p.data.Front() != nil {
+ if p.HasReaders() && p.view.Size() != 0 {
ready |= waiter.EventIn
}
if !p.HasWriters() && p.hadWriter {
@@ -422,7 +346,7 @@ func (p *Pipe) rReadiness() waiter.EventMask {
// Precondition: mu must be held.
func (p *Pipe) wReadinessLocked() waiter.EventMask {
ready := waiter.EventMask(0)
- if p.HasWriters() && p.size < p.max {
+ if p.HasWriters() && p.view.Size() < p.max {
ready |= waiter.EventOut
}
if !p.HasReaders() {
@@ -451,7 +375,7 @@ func (p *Pipe) rwReadiness() waiter.EventMask {
func (p *Pipe) queued() int64 {
p.mu.Lock()
defer p.mu.Unlock()
- return p.size
+ return p.view.Size()
}
// FifoSize implements fs.FifoSizer.FifoSize.
@@ -474,7 +398,7 @@ func (p *Pipe) SetFifoSize(size int64) (int64, error) {
}
p.mu.Lock()
defer p.mu.Unlock()
- if size < p.size {
+ if size < p.view.Size() {
return 0, syserror.EBUSY
}
p.max = size
diff --git a/pkg/sentry/kernel/pipe/pipe_util.go b/pkg/sentry/kernel/pipe/pipe_util.go
index 80158239e..5a1d4fd57 100644
--- a/pkg/sentry/kernel/pipe/pipe_util.go
+++ b/pkg/sentry/kernel/pipe/pipe_util.go
@@ -21,6 +21,7 @@ import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/amutex"
+ "gvisor.dev/gvisor/pkg/buffer"
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/sentry/arch"
"gvisor.dev/gvisor/pkg/sync"
@@ -49,9 +50,10 @@ func (p *Pipe) Read(ctx context.Context, dst usermem.IOSequence) (int64, error)
limit: func(l int64) {
dst = dst.TakeFirst64(l)
},
- read: func(buf *buffer) (int64, error) {
- n, err := dst.CopyOutFrom(ctx, buf)
+ read: func(view *buffer.View) (int64, error) {
+ n, err := dst.CopyOutFrom(ctx, view)
dst = dst.DropFirst64(n)
+ view.TrimFront(n)
return n, err
},
})
@@ -70,16 +72,15 @@ func (p *Pipe) WriteTo(ctx context.Context, w io.Writer, count int64, dup bool)
limit: func(l int64) {
count = l
},
- read: func(buf *buffer) (int64, error) {
- n, err := buf.ReadToWriter(w, count, dup)
+ read: func(view *buffer.View) (int64, error) {
+ n, err := view.ReadToWriter(w, count)
+ if !dup {
+ view.TrimFront(n)
+ }
count -= n
return n, err
},
}
- if dup {
- // There is no notification for dup operations.
- return p.dup(ctx, ops)
- }
n, err := p.read(ctx, ops)
if n > 0 {
p.Notify(waiter.EventOut)
@@ -96,8 +97,8 @@ func (p *Pipe) Write(ctx context.Context, src usermem.IOSequence) (int64, error)
limit: func(l int64) {
src = src.TakeFirst64(l)
},
- write: func(buf *buffer) (int64, error) {
- n, err := src.CopyInTo(ctx, buf)
+ write: func(view *buffer.View) (int64, error) {
+ n, err := src.CopyInTo(ctx, view)
src = src.DropFirst64(n)
return n, err
},
@@ -117,8 +118,8 @@ func (p *Pipe) ReadFrom(ctx context.Context, r io.Reader, count int64) (int64, e
limit: func(l int64) {
count = l
},
- write: func(buf *buffer) (int64, error) {
- n, err := buf.WriteFromReader(r, count)
+ write: func(view *buffer.View) (int64, error) {
+ n, err := view.WriteFromReader(r, count)
count -= n
return n, err
},
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.
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-29 00:50:00 +0000