Enable automated marshalling for epoll events.

Ensure we use the correct architecture-specific defintion of epoll
event, and use go-marshal for serialization.

PiperOrigin-RevId: 308145677

2 files changed, 5 insertions, 16 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 592650923..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,
 		})