Use memutil.MapFile for the memory accounting page.

PiperOrigin-RevId: 381145216

2 files changed, 4 insertions, 4 deletions

diff --git a/pkg/sentry/usage/memory.go b/pkg/sentry/usage/memory.go
index 581862ee2..e7073ec87 100644
--- a/pkg/sentry/usage/memory.go
+++ b/pkg/sentry/usage/memory.go
@@ -132,7 +132,7 @@ func Init() error {
 	// always be the case for a newly mapped page from /dev/shm. If we obtain
 	// the shared memory through some other means in the future, we may have to
 	// explicitly zero the page.
-	mmap, err := unix.Mmap(int(file.Fd()), 0, int(RTMemoryStatsSize), unix.PROT_READ|unix.PROT_WRITE, unix.MAP_SHARED)
+	mmap, err := memutil.MapFile(0, RTMemoryStatsSize, unix.PROT_READ|unix.PROT_WRITE, unix.MAP_SHARED, file.Fd(), 0)
 	if err != nil {
 		return fmt.Errorf("error mapping usage file: %v", err)
 	}
diff --git a/pkg/sentry/usage/memory_unsafe.go b/pkg/sentry/usage/memory_unsafe.go
index 9e0014ca0..bc1531b91 100644
--- a/pkg/sentry/usage/memory_unsafe.go
+++ b/pkg/sentry/usage/memory_unsafe.go
@@ -21,7 +21,7 @@ import (
 // RTMemoryStatsSize is the size of the RTMemoryStats struct.
 var RTMemoryStatsSize = unsafe.Sizeof(RTMemoryStats{})
 
-// RTMemoryStatsPointer casts the address of the byte slice into a RTMemoryStats pointer.
-func RTMemoryStatsPointer(b []byte) *RTMemoryStats {
-	return (*RTMemoryStats)(unsafe.Pointer(&b[0]))
+// RTMemoryStatsPointer casts addr to a RTMemoryStats pointer.
+func RTMemoryStatsPointer(addr uintptr) *RTMemoryStats {
+	return (*RTMemoryStats)(unsafe.Pointer(addr))
 }