3 files changed, 15 insertions, 21 deletions

diff --git a/pkg/sentry/kernel/epoll/BUILD b/pkg/sentry/kernel/epoll/BUILD
index dedf0fa15..75eedd5a2 100644
--- a/pkg/sentry/kernel/epoll/BUILD
+++ b/pkg/sentry/kernel/epoll/BUILD
@@ -24,6 +24,7 @@ go_library(
     ],
     visibility = ["//pkg/sentry:internal"],
     deps = [
+        "//pkg/abi/linux",
         "//pkg/context",
         "//pkg/refs",
         "//pkg/sentry/fs",
diff --git a/pkg/sentry/kernel/epoll/epoll.go b/pkg/sentry/kernel/epoll/epoll.go
index 8bffb78fc..3d78cd48f 100644
--- a/pkg/sentry/kernel/epoll/epoll.go
+++ b/pkg/sentry/kernel/epoll/epoll.go
@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"syscall"
 
+	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/refs"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
@@ -30,19 +31,6 @@ import (
 	"gvisor.dev/gvisor/pkg/waiter"
 )
 
-// Event describes the event mask that was observed and the user data to be
-// returned when one of the events occurs. It has this format to match the linux
-// format to avoid extra copying/allocation when writing events to userspace.
-type Event struct {
-	// Events is the event mask containing the set of events that have been
-	// observed on an entry.
-	Events uint32
-
-	// Data is an opaque 64-bit value provided by the caller when adding the
-	// entry, and returned to the caller when the entry reports an event.
-	Data [2]int32
-}
-
 // EntryFlags is a bitmask that holds an entry's flags.
 type EntryFlags int
 
@@ -227,9 +215,9 @@ func (e *EventPoll) Readiness(mask waiter.EventMask) waiter.EventMask {
 }
 
 // ReadEvents returns up to max available events.
-func (e *EventPoll) ReadEvents(max int) []Event {
+func (e *EventPoll) ReadEvents(max int) []linux.EpollEvent {
 	var local pollEntryList
-	var ret []Event
+	var ret []linux.EpollEvent
 
 	e.listsMu.Lock()
 
@@ -251,7 +239,7 @@ func (e *EventPoll) ReadEvents(max int) []Event {
 		}
 
 		// Add event to the array that will be returned to caller.
-		ret = append(ret, Event{
+		ret = append(ret, linux.EpollEvent{
 			Events: uint32(ready),
 			Data:   entry.userData,
 		})
@@ -296,8 +284,10 @@ func (*readyCallback) Callback(w *waiter.Entry) {
 		e.waitingList.Remove(entry)
 		e.readyList.PushBack(entry)
 		entry.curList = &e.readyList
+		e.listsMu.Unlock()
 
 		e.Notify(waiter.EventIn)
+		return
 	}
 
 	e.listsMu.Unlock()
diff --git a/pkg/sentry/kernel/epoll/epoll_state.go b/pkg/sentry/kernel/epoll/epoll_state.go
index a0d35d350..8e9f200d0 100644
--- a/pkg/sentry/kernel/epoll/epoll_state.go
+++ b/pkg/sentry/kernel/epoll/epoll_state.go
@@ -38,11 +38,14 @@ func (e *EventPoll) afterLoad() {
 		}
 	}
 
-	for it := e.waitingList.Front(); it != nil; it = it.Next() {
-		if it.id.File.Readiness(it.mask) != 0 {
-			e.waitingList.Remove(it)
-			e.readyList.PushBack(it)
-			it.curList = &e.readyList
+	for it := e.waitingList.Front(); it != nil; {
+		entry := it
+		it = it.Next()
+
+		if entry.id.File.Readiness(entry.mask) != 0 {
+			e.waitingList.Remove(entry)
+			e.readyList.PushBack(entry)
+			entry.curList = &e.readyList
 			e.Notify(waiter.EventIn)
 		}
 	}