summaryrefslogtreecommitdiffhomepage
diff options
context:
space:
mode:
authorgVisor bot <gvisor-bot@google.com>2020-10-30 20:57:55 +0000
committergVisor bot <gvisor-bot@google.com>2020-10-30 20:57:55 +0000
commitfb1c8c76ad115e2c6ca370b0fc392d7f4c601a31 (patch)
treef35403014d7363bd44c772e9d1202eaba58c2390
parent27c7f1c9cba567579fb7e7065d2fb86157d88ba3 (diff)
parent9ad864628dc3f36a24a5eb6a51d7e13471598517 (diff)
Merge release-20201019.0-111-g9ad864628 (automated)
-rw-r--r--pkg/sentry/kernel/ptrace.go4
-rw-r--r--pkg/sentry/kernel/task_clone.go2
-rw-r--r--pkg/sentry/kernel/task_usermem.go95
3 files changed, 81 insertions, 20 deletions
diff --git a/pkg/sentry/kernel/ptrace.go b/pkg/sentry/kernel/ptrace.go
index 1145faf13..1abfe2201 100644
--- a/pkg/sentry/kernel/ptrace.go
+++ b/pkg/sentry/kernel/ptrace.go
@@ -1000,7 +1000,7 @@ func (t *Task) Ptrace(req int64, pid ThreadID, addr, data usermem.Addr) error {
// at the address specified by the data parameter, and the return value
// is the error flag." - ptrace(2)
word := t.Arch().Native(0)
- if _, err := word.CopyIn(target.AsCopyContext(usermem.IOOpts{IgnorePermissions: true}), addr); err != nil {
+ if _, err := word.CopyIn(target.CopyContext(t, usermem.IOOpts{IgnorePermissions: true}), addr); err != nil {
return err
}
_, err := word.CopyOut(t, data)
@@ -1008,7 +1008,7 @@ func (t *Task) Ptrace(req int64, pid ThreadID, addr, data usermem.Addr) error {
case linux.PTRACE_POKETEXT, linux.PTRACE_POKEDATA:
word := t.Arch().Native(uintptr(data))
- _, err := word.CopyOut(target.AsCopyContext(usermem.IOOpts{IgnorePermissions: true}), addr)
+ _, err := word.CopyOut(target.CopyContext(t, usermem.IOOpts{IgnorePermissions: true}), addr)
return err
case linux.PTRACE_GETREGSET:
diff --git a/pkg/sentry/kernel/task_clone.go b/pkg/sentry/kernel/task_clone.go
index 682080c14..527344162 100644
--- a/pkg/sentry/kernel/task_clone.go
+++ b/pkg/sentry/kernel/task_clone.go
@@ -355,7 +355,7 @@ func (t *Task) Clone(opts *CloneOptions) (ThreadID, *SyscallControl, error) {
}
if opts.ChildSetTID {
ctid := nt.ThreadID()
- ctid.CopyOut(nt.AsCopyContext(usermem.IOOpts{AddressSpaceActive: false}), opts.ChildTID)
+ ctid.CopyOut(nt.CopyContext(t, usermem.IOOpts{AddressSpaceActive: false}), opts.ChildTID)
}
ntid := t.tg.pidns.IDOfTask(nt)
if opts.ParentSetTID {
diff --git a/pkg/sentry/kernel/task_usermem.go b/pkg/sentry/kernel/task_usermem.go
index ce134bf54..94dabbcd8 100644
--- a/pkg/sentry/kernel/task_usermem.go
+++ b/pkg/sentry/kernel/task_usermem.go
@@ -18,7 +18,8 @@ import (
"math"
"gvisor.dev/gvisor/pkg/abi/linux"
- "gvisor.dev/gvisor/pkg/marshal"
+ "gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/sentry/mm"
"gvisor.dev/gvisor/pkg/syserror"
"gvisor.dev/gvisor/pkg/usermem"
)
@@ -281,29 +282,89 @@ func (t *Task) IovecsIOSequence(addr usermem.Addr, iovcnt int, opts usermem.IOOp
}, nil
}
-// copyContext implements marshal.CopyContext. It wraps a task to allow copying
-// memory to and from the task memory with custom usermem.IOOpts.
-type copyContext struct {
- *Task
+type taskCopyContext struct {
+ ctx context.Context
+ t *Task
opts usermem.IOOpts
}
-// AsCopyContext wraps the task and returns it as CopyContext.
-func (t *Task) AsCopyContext(opts usermem.IOOpts) marshal.CopyContext {
- return &copyContext{t, opts}
+// CopyContext returns a marshal.CopyContext that copies to/from t's address
+// space using opts.
+func (t *Task) CopyContext(ctx context.Context, opts usermem.IOOpts) *taskCopyContext {
+ return &taskCopyContext{
+ ctx: ctx,
+ t: t,
+ opts: opts,
+ }
+}
+
+// CopyScratchBuffer implements marshal.CopyContext.CopyScratchBuffer.
+func (cc *taskCopyContext) CopyScratchBuffer(size int) []byte {
+ if ctxTask, ok := cc.ctx.(*Task); ok {
+ return ctxTask.CopyScratchBuffer(size)
+ }
+ return make([]byte, size)
+}
+
+func (cc *taskCopyContext) getMemoryManager() (*mm.MemoryManager, error) {
+ cc.t.mu.Lock()
+ tmm := cc.t.MemoryManager()
+ cc.t.mu.Unlock()
+ if !tmm.IncUsers() {
+ return nil, syserror.EFAULT
+ }
+ return tmm, nil
+}
+
+// CopyInBytes implements marshal.CopyContext.CopyInBytes.
+func (cc *taskCopyContext) CopyInBytes(addr usermem.Addr, dst []byte) (int, error) {
+ tmm, err := cc.getMemoryManager()
+ if err != nil {
+ return 0, err
+ }
+ defer tmm.DecUsers(cc.ctx)
+ return tmm.CopyIn(cc.ctx, addr, dst, cc.opts)
+}
+
+// CopyOutBytes implements marshal.CopyContext.CopyOutBytes.
+func (cc *taskCopyContext) CopyOutBytes(addr usermem.Addr, src []byte) (int, error) {
+ tmm, err := cc.getMemoryManager()
+ if err != nil {
+ return 0, err
+ }
+ defer tmm.DecUsers(cc.ctx)
+ return tmm.CopyOut(cc.ctx, addr, src, cc.opts)
+}
+
+type ownTaskCopyContext struct {
+ t *Task
+ opts usermem.IOOpts
+}
+
+// OwnCopyContext returns a marshal.CopyContext that copies to/from t's address
+// space using opts. The returned CopyContext may only be used by t's task
+// goroutine.
+//
+// Since t already implements marshal.CopyContext, this is only needed to
+// override the usermem.IOOpts used for the copy.
+func (t *Task) OwnCopyContext(opts usermem.IOOpts) *ownTaskCopyContext {
+ return &ownTaskCopyContext{
+ t: t,
+ opts: opts,
+ }
}
-// CopyInString copies a string in from the task's memory.
-func (t *copyContext) CopyInString(addr usermem.Addr, maxLen int) (string, error) {
- return usermem.CopyStringIn(t, t.MemoryManager(), addr, maxLen, t.opts)
+// CopyScratchBuffer implements marshal.CopyContext.CopyScratchBuffer.
+func (cc *ownTaskCopyContext) CopyScratchBuffer(size int) []byte {
+ return cc.t.CopyScratchBuffer(size)
}
-// CopyInBytes copies task memory into dst from an IO context.
-func (t *copyContext) CopyInBytes(addr usermem.Addr, dst []byte) (int, error) {
- return t.MemoryManager().CopyIn(t, addr, dst, t.opts)
+// CopyInBytes implements marshal.CopyContext.CopyInBytes.
+func (cc *ownTaskCopyContext) CopyInBytes(addr usermem.Addr, dst []byte) (int, error) {
+ return cc.t.MemoryManager().CopyIn(cc.t, addr, dst, cc.opts)
}
-// CopyOutBytes copies src into task memoryfrom an IO context.
-func (t *copyContext) CopyOutBytes(addr usermem.Addr, src []byte) (int, error) {
- return t.MemoryManager().CopyOut(t, addr, src, t.opts)
+// CopyOutBytes implements marshal.CopyContext.CopyOutBytes.
+func (cc *ownTaskCopyContext) CopyOutBytes(addr usermem.Addr, src []byte) (int, error) {
+ return cc.t.MemoryManager().CopyOut(cc.t, addr, src, cc.opts)
}