Drop unnecessary cast.

Bitshift operators with signed int is supported in Go 1.13.

PiperOrigin-RevId: 285853622

3 files changed, 20 insertions, 20 deletions

diff --git a/go.mod b/go.mod
index 821273d22..304b8bf13 100644
--- a/go.mod
+++ b/go.mod
@@ -1,21 +1,21 @@
 module gvisor.dev/gvisor
 
-go 1.12
+go 1.13
 
 require (
-	github.com/cenkalti/backoff v0.0.0-20190506075156-2146c9339422
-	github.com/gofrs/flock v0.6.1-0.20180915234121-886344bea079
-	github.com/golang/mock v1.3.1
-	github.com/golang/protobuf v1.3.1
-	github.com/google/btree v1.0.0
-	github.com/google/go-cmp v0.2.0
-	github.com/google/subcommands v0.0.0-20190508160503-636abe8753b8
-	github.com/google/uuid v0.0.0-20171129191014-dec09d789f3d
-	github.com/kr/pty v1.1.1
-	github.com/opencontainers/runtime-spec v0.1.2-0.20171211145439-b2d941ef6a78
-	github.com/syndtr/gocapability v0.0.0-20180916011248-d98352740cb2
-	github.com/vishvananda/netlink v1.0.1-0.20190318003149-adb577d4a45e
-	github.com/vishvananda/netns v0.0.0-20171111001504-be1fbeda1936
-	golang.org/x/net v0.0.0-20190311183353-d8887717615a
-	golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a
+  github.com/cenkalti/backoff v0.0.0-20190506075156-2146c9339422
+  github.com/gofrs/flock v0.6.1-0.20180915234121-886344bea079
+  github.com/golang/mock v1.3.1
+  github.com/golang/protobuf v1.3.1
+  github.com/google/btree v1.0.0
+  github.com/google/go-cmp v0.2.0
+  github.com/google/subcommands v0.0.0-20190508160503-636abe8753b8
+  github.com/google/uuid v0.0.0-20171129191014-dec09d789f3d
+  github.com/kr/pty v1.1.1
+  github.com/opencontainers/runtime-spec v0.1.2-0.20171211145439-b2d941ef6a78
+  github.com/syndtr/gocapability v0.0.0-20180916011248-d98352740cb2
+  github.com/vishvananda/netlink v1.0.1-0.20190318003149-adb577d4a45e
+  github.com/vishvananda/netns v0.0.0-20171111001504-be1fbeda1936
+  golang.org/x/net v0.0.0-20190311183353-d8887717615a
+  golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a
 )
diff --git a/pkg/sentry/strace/select.go b/pkg/sentry/strace/select.go
index 92c18083d..dea309fda 100644
--- a/pkg/sentry/strace/select.go
+++ b/pkg/sentry/strace/select.go
@@ -27,7 +27,7 @@ func fdsFromSet(t *kernel.Task, set []byte) []int {
 	// Append n if the n-th bit is 1.
 	for i, v := range set {
 		for j := 0; j < 8; j++ {
-			if (v>>uint(j))&1 == 1 {
+			if (v>>j)&1 == 1 {
 				fds = append(fds, i*8+j)
 			}
 		}
@@ -42,7 +42,7 @@ func fdSet(t *kernel.Task, nfds int, addr usermem.Addr) string {
 
 	// Calculate the size of the fd set (one bit per fd).
 	nBytes := (nfds + 7) / 8
-	nBitsInLastPartialByte := uint(nfds % 8)
+	nBitsInLastPartialByte := nfds % 8
 
 	set, err := linux.CopyInFDSet(t, addr, nBytes, nBitsInLastPartialByte)
 	if err != nil {
diff --git a/pkg/sentry/syscalls/linux/sys_poll.go b/pkg/sentry/syscalls/linux/sys_poll.go
index 631dffec6..2b2df989a 100644
--- a/pkg/sentry/syscalls/linux/sys_poll.go
+++ b/pkg/sentry/syscalls/linux/sys_poll.go
@@ -198,7 +198,7 @@ func doPoll(t *kernel.Task, addr usermem.Addr, nfds uint, timeout time.Duration)
 }
 
 // CopyInFDSet copies an fd set from select(2)/pselect(2).
-func CopyInFDSet(t *kernel.Task, addr usermem.Addr, nBytes int, nBitsInLastPartialByte uint) ([]byte, error) {
+func CopyInFDSet(t *kernel.Task, addr usermem.Addr, nBytes, nBitsInLastPartialByte int) ([]byte, error) {
 	set := make([]byte, nBytes)
 
 	if addr != 0 {
@@ -222,7 +222,7 @@ func doSelect(t *kernel.Task, nfds int, readFDs, writeFDs, exceptFDs usermem.Add
 
 	// Calculate the size of the fd sets (one bit per fd).
 	nBytes := (nfds + 7) / 8
-	nBitsInLastPartialByte := uint(nfds % 8)
+	nBitsInLastPartialByte := nfds % 8
 
 	// Capture all the provided input vectors.
 	r, err := CopyInFDSet(t, readFDs, nBytes, nBitsInLastPartialByte)