pkg/p9: populate attr.RDev from s.Rdev in StatToAttr

Populate attr.RDev with s.Rdev (special device number) rather than s.Dev
(containing filesystem ID) in p9.StatToAttr.

PiperOrigin-RevId: 966213832

pkg/p9/p9.go

@@ -536,7 +536,7 @@ func StatToAttr(s *syscall.Stat_t, req AttrMask) (Attr, AttrMask) {
 		attr.GID = GID(s.Gid)
 	}
 	if req.RDev {
-		attr.RDev = s.Dev
+		attr.RDev = s.Rdev
 	}
 	if req.ATime {
 		attr.ATimeSeconds = uint64(s.Atim.Sec)

pkg/sentry/loader/loader.go

@@ -245,7 +245,7 @@ func loadExecutable(ctx context.Context, args LoadArgs) (loadedELF, *arch.Contex
 			*args.RemainingTraversals = linux.MaxSymlinkTraversals
 
 		default:
-			ctx.Infof("Unknown magic: %v", hdr)
+			ctx.Infof("Unknown magic for %s: %v", args.Filename, hdr)
 			return loadedELF{}, nil, nil, nil, linuxerr.ENOEXEC
 		}
 		// Set to nil in case we loop on a Interpreter Script.