3 files changed, 432 insertions, 35 deletions
diff --git a/pkg/sentry/kernel/mq/BUILD b/pkg/sentry/kernel/mq/BUILD
deleted file mode 100644
index fefac3ba5..000000000
--- a/pkg/sentry/kernel/mq/BUILD
+++ /dev/null
@@ -1,35 +0,0 @@
-load("//tools:defs.bzl", "go_library")
-load("//tools/go_generics:defs.bzl", "go_template_instance")
-
-package(licenses = ["notice"])
-
-go_template_instance(
-    name = "message_list",
-    out = "message_list.go",
-    package = "mq",
-    prefix = "msg",
-    template = "//pkg/ilist:generic_list",
-    types = {
-        "Element": "*Message",
-        "Linker": "*Message",
-    },
-)
-
-go_library(
-    name = "mq",
-    srcs = [
-        "message_list.go",
-        "mq.go",
-    ],
-    visibility = ["//pkg/sentry:internal"],
-    deps = [
-        "//pkg/abi/linux",
-        "//pkg/context",
-        "//pkg/errors/linuxerr",
-        "//pkg/sentry/fs",
-        "//pkg/sentry/kernel/auth",
-        "//pkg/sentry/vfs",
-        "//pkg/sync",
-        "//pkg/waiter",
-    ],
-)
diff --git a/pkg/sentry/kernel/mq/message_list.go b/pkg/sentry/kernel/mq/message_list.go
new file mode 100644
index 000000000..a5874c5b1
--- /dev/null
+++ b/pkg/sentry/kernel/mq/message_list.go
@@ -0,0 +1,221 @@
+package mq
+
+// ElementMapper provides an identity mapping by default.
+//
+// This can be replaced to provide a struct that maps elements to linker
+// objects, if they are not the same. An ElementMapper is not typically
+// required if: Linker is left as is, Element is left as is, or Linker and
+// Element are the same type.
+type msgElementMapper struct{}
+
+// linkerFor maps an Element to a Linker.
+//
+// This default implementation should be inlined.
+//
+//go:nosplit
+func (msgElementMapper) linkerFor(elem *Message) *Message { return elem }
+
+// List is an intrusive list. Entries can be added to or removed from the list
+// in O(1) time and with no additional memory allocations.
+//
+// The zero value for List is an empty list ready to use.
+//
+// To iterate over a list (where l is a List):
+//      for e := l.Front(); e != nil; e = e.Next() {
+// 		// do something with e.
+//      }
+//
+// +stateify savable
+type msgList struct {
+	head *Message
+	tail *Message
+}
+
+// Reset resets list l to the empty state.
+func (l *msgList) Reset() {
+	l.head = nil
+	l.tail = nil
+}
+
+// Empty returns true iff the list is empty.
+//
+//go:nosplit
+func (l *msgList) Empty() bool {
+	return l.head == nil
+}
+
+// Front returns the first element of list l or nil.
+//
+//go:nosplit
+func (l *msgList) Front() *Message {
+	return l.head
+}
+
+// Back returns the last element of list l or nil.
+//
+//go:nosplit
+func (l *msgList) Back() *Message {
+	return l.tail
+}
+
+// Len returns the number of elements in the list.
+//
+// NOTE: This is an O(n) operation.
+//
+//go:nosplit
+func (l *msgList) Len() (count int) {
+	for e := l.Front(); e != nil; e = (msgElementMapper{}.linkerFor(e)).Next() {
+		count++
+	}
+	return count
+}
+
+// PushFront inserts the element e at the front of list l.
+//
+//go:nosplit
+func (l *msgList) PushFront(e *Message) {
+	linker := msgElementMapper{}.linkerFor(e)
+	linker.SetNext(l.head)
+	linker.SetPrev(nil)
+	if l.head != nil {
+		msgElementMapper{}.linkerFor(l.head).SetPrev(e)
+	} else {
+		l.tail = e
+	}
+
+	l.head = e
+}
+
+// PushBack inserts the element e at the back of list l.
+//
+//go:nosplit
+func (l *msgList) PushBack(e *Message) {
+	linker := msgElementMapper{}.linkerFor(e)
+	linker.SetNext(nil)
+	linker.SetPrev(l.tail)
+	if l.tail != nil {
+		msgElementMapper{}.linkerFor(l.tail).SetNext(e)
+	} else {
+		l.head = e
+	}
+
+	l.tail = e
+}
+
+// PushBackList inserts list m at the end of list l, emptying m.
+//
+//go:nosplit
+func (l *msgList) PushBackList(m *msgList) {
+	if l.head == nil {
+		l.head = m.head
+		l.tail = m.tail
+	} else if m.head != nil {
+		msgElementMapper{}.linkerFor(l.tail).SetNext(m.head)
+		msgElementMapper{}.linkerFor(m.head).SetPrev(l.tail)
+
+		l.tail = m.tail
+	}
+	m.head = nil
+	m.tail = nil
+}
+
+// InsertAfter inserts e after b.
+//
+//go:nosplit
+func (l *msgList) InsertAfter(b, e *Message) {
+	bLinker := msgElementMapper{}.linkerFor(b)
+	eLinker := msgElementMapper{}.linkerFor(e)
+
+	a := bLinker.Next()
+
+	eLinker.SetNext(a)
+	eLinker.SetPrev(b)
+	bLinker.SetNext(e)
+
+	if a != nil {
+		msgElementMapper{}.linkerFor(a).SetPrev(e)
+	} else {
+		l.tail = e
+	}
+}
+
+// InsertBefore inserts e before a.
+//
+//go:nosplit
+func (l *msgList) InsertBefore(a, e *Message) {
+	aLinker := msgElementMapper{}.linkerFor(a)
+	eLinker := msgElementMapper{}.linkerFor(e)
+
+	b := aLinker.Prev()
+	eLinker.SetNext(a)
+	eLinker.SetPrev(b)
+	aLinker.SetPrev(e)
+
+	if b != nil {
+		msgElementMapper{}.linkerFor(b).SetNext(e)
+	} else {
+		l.head = e
+	}
+}
+
+// Remove removes e from l.
+//
+//go:nosplit
+func (l *msgList) Remove(e *Message) {
+	linker := msgElementMapper{}.linkerFor(e)
+	prev := linker.Prev()
+	next := linker.Next()
+
+	if prev != nil {
+		msgElementMapper{}.linkerFor(prev).SetNext(next)
+	} else if l.head == e {
+		l.head = next
+	}
+
+	if next != nil {
+		msgElementMapper{}.linkerFor(next).SetPrev(prev)
+	} else if l.tail == e {
+		l.tail = prev
+	}
+
+	linker.SetNext(nil)
+	linker.SetPrev(nil)
+}
+
+// Entry is a default implementation of Linker. Users can add anonymous fields
+// of this type to their structs to make them automatically implement the
+// methods needed by List.
+//
+// +stateify savable
+type msgEntry struct {
+	next *Message
+	prev *Message
+}
+
+// Next returns the entry that follows e in the list.
+//
+//go:nosplit
+func (e *msgEntry) Next() *Message {
+	return e.next
+}
+
+// Prev returns the entry that precedes e in the list.
+//
+//go:nosplit
+func (e *msgEntry) Prev() *Message {
+	return e.prev
+}
+
+// SetNext assigns 'entry' as the entry that follows e in the list.
+//
+//go:nosplit
+func (e *msgEntry) SetNext(elem *Message) {
+	e.next = elem
+}
+
+// SetPrev assigns 'entry' as the entry that precedes e in the list.
+//
+//go:nosplit
+func (e *msgEntry) SetPrev(elem *Message) {
+	e.prev = elem
+}
diff --git a/pkg/sentry/kernel/mq/mq_state_autogen.go b/pkg/sentry/kernel/mq/mq_state_autogen.go
new file mode 100644
index 000000000..4833c9b4e
--- /dev/null
+++ b/pkg/sentry/kernel/mq/mq_state_autogen.go
@@ -0,0 +1,211 @@
+// automatically generated by stateify.
+
+package mq
+
+import (
+	"gvisor.dev/gvisor/pkg/state"
+)
+
+func (l *msgList) StateTypeName() string {
+	return "pkg/sentry/kernel/mq.msgList"
+}
+
+func (l *msgList) StateFields() []string {
+	return []string{
+		"head",
+		"tail",
+	}
+}
+
+func (l *msgList) beforeSave() {}
+
+// +checklocksignore
+func (l *msgList) StateSave(stateSinkObject state.Sink) {
+	l.beforeSave()
+	stateSinkObject.Save(0, &l.head)
+	stateSinkObject.Save(1, &l.tail)
+}
+
+func (l *msgList) afterLoad() {}
+
+// +checklocksignore
+func (l *msgList) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &l.head)
+	stateSourceObject.Load(1, &l.tail)
+}
+
+func (e *msgEntry) StateTypeName() string {
+	return "pkg/sentry/kernel/mq.msgEntry"
+}
+
+func (e *msgEntry) StateFields() []string {
+	return []string{
+		"next",
+		"prev",
+	}
+}
+
+func (e *msgEntry) beforeSave() {}
+
+// +checklocksignore
+func (e *msgEntry) StateSave(stateSinkObject state.Sink) {
+	e.beforeSave()
+	stateSinkObject.Save(0, &e.next)
+	stateSinkObject.Save(1, &e.prev)
+}
+
+func (e *msgEntry) afterLoad() {}
+
+// +checklocksignore
+func (e *msgEntry) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &e.next)
+	stateSourceObject.Load(1, &e.prev)
+}
+
+func (r *Registry) StateTypeName() string {
+	return "pkg/sentry/kernel/mq.Registry"
+}
+
+func (r *Registry) StateFields() []string {
+	return []string{
+		"userNS",
+		"impl",
+	}
+}
+
+func (r *Registry) beforeSave() {}
+
+// +checklocksignore
+func (r *Registry) StateSave(stateSinkObject state.Sink) {
+	r.beforeSave()
+	stateSinkObject.Save(0, &r.userNS)
+	stateSinkObject.Save(1, &r.impl)
+}
+
+func (r *Registry) afterLoad() {}
+
+// +checklocksignore
+func (r *Registry) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &r.userNS)
+	stateSourceObject.Load(1, &r.impl)
+}
+
+func (q *Queue) StateTypeName() string {
+	return "pkg/sentry/kernel/mq.Queue"
+}
+
+func (q *Queue) StateFields() []string {
+	return []string{
+		"owner",
+		"perms",
+		"senders",
+		"receivers",
+		"messages",
+		"subscriber",
+		"messageCount",
+		"maxMessageCount",
+		"maxMessageSize",
+		"byteCount",
+	}
+}
+
+func (q *Queue) beforeSave() {}
+
+// +checklocksignore
+func (q *Queue) StateSave(stateSinkObject state.Sink) {
+	q.beforeSave()
+	stateSinkObject.Save(0, &q.owner)
+	stateSinkObject.Save(1, &q.perms)
+	stateSinkObject.Save(2, &q.senders)
+	stateSinkObject.Save(3, &q.receivers)
+	stateSinkObject.Save(4, &q.messages)
+	stateSinkObject.Save(5, &q.subscriber)
+	stateSinkObject.Save(6, &q.messageCount)
+	stateSinkObject.Save(7, &q.maxMessageCount)
+	stateSinkObject.Save(8, &q.maxMessageSize)
+	stateSinkObject.Save(9, &q.byteCount)
+}
+
+func (q *Queue) afterLoad() {}
+
+// +checklocksignore
+func (q *Queue) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &q.owner)
+	stateSourceObject.Load(1, &q.perms)
+	stateSourceObject.Load(2, &q.senders)
+	stateSourceObject.Load(3, &q.receivers)
+	stateSourceObject.Load(4, &q.messages)
+	stateSourceObject.Load(5, &q.subscriber)
+	stateSourceObject.Load(6, &q.messageCount)
+	stateSourceObject.Load(7, &q.maxMessageCount)
+	stateSourceObject.Load(8, &q.maxMessageSize)
+	stateSourceObject.Load(9, &q.byteCount)
+}
+
+func (m *Message) StateTypeName() string {
+	return "pkg/sentry/kernel/mq.Message"
+}
+
+func (m *Message) StateFields() []string {
+	return []string{
+		"msgEntry",
+		"Text",
+		"Size",
+		"Priority",
+	}
+}
+
+func (m *Message) beforeSave() {}
+
+// +checklocksignore
+func (m *Message) StateSave(stateSinkObject state.Sink) {
+	m.beforeSave()
+	stateSinkObject.Save(0, &m.msgEntry)
+	stateSinkObject.Save(1, &m.Text)
+	stateSinkObject.Save(2, &m.Size)
+	stateSinkObject.Save(3, &m.Priority)
+}
+
+func (m *Message) afterLoad() {}
+
+// +checklocksignore
+func (m *Message) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &m.msgEntry)
+	stateSourceObject.Load(1, &m.Text)
+	stateSourceObject.Load(2, &m.Size)
+	stateSourceObject.Load(3, &m.Priority)
+}
+
+func (s *Subscriber) StateTypeName() string {
+	return "pkg/sentry/kernel/mq.Subscriber"
+}
+
+func (s *Subscriber) StateFields() []string {
+	return []string{
+		"pid",
+	}
+}
+
+func (s *Subscriber) beforeSave() {}
+
+// +checklocksignore
+func (s *Subscriber) StateSave(stateSinkObject state.Sink) {
+	s.beforeSave()
+	stateSinkObject.Save(0, &s.pid)
+}
+
+func (s *Subscriber) afterLoad() {}
+
+// +checklocksignore
+func (s *Subscriber) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &s.pid)
+}
+
+func init() {
+	state.Register((*msgList)(nil))
+	state.Register((*msgEntry)(nil))
+	state.Register((*Registry)(nil))
+	state.Register((*Queue)(nil))
+	state.Register((*Message)(nil))
+	state.Register((*Subscriber)(nil))
+}