Create ipc package and ipc.Object.

Create ipc.Object to define fields and functionality used in SysV
mechanisms, and have them use it.

3 files changed, 28 insertions, 25 deletions

diff --git a/pkg/sentry/syscalls/linux/BUILD b/pkg/sentry/syscalls/linux/BUILD
index a2f612f45..7941b2be9 100644
--- a/pkg/sentry/syscalls/linux/BUILD
+++ b/pkg/sentry/syscalls/linux/BUILD
@@ -84,6 +84,7 @@ go_library(
         "//pkg/sentry/kernel/epoll",
         "//pkg/sentry/kernel/eventfd",
         "//pkg/sentry/kernel/fasync",
+        "//pkg/sentry/kernel/ipc",
         "//pkg/sentry/kernel/pipe",
         "//pkg/sentry/kernel/sched",
         "//pkg/sentry/kernel/shm",
diff --git a/pkg/sentry/syscalls/linux/sys_sem.go b/pkg/sentry/syscalls/linux/sys_sem.go
index 30919eb2f..4755bef18 100644
--- a/pkg/sentry/syscalls/linux/sys_sem.go
+++ b/pkg/sentry/syscalls/linux/sys_sem.go
@@ -26,13 +26,14 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+	"gvisor.dev/gvisor/pkg/sentry/kernel/ipc"
 )
 
 const opsMax = 500 // SEMOPM
 
 // Semget handles: semget(key_t key, int nsems, int semflg)
 func Semget(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
-	key := args[0].Int()
+	key := ipc.Key(args[0].Int())
 	nsems := args[1].Int()
 	flag := args[2].Int()
 
@@ -46,7 +47,7 @@ func Semget(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
 	if err != nil {
 		return 0, nil, err
 	}
-	return uintptr(set.ID), nil, nil
+	return uintptr(set.ID()), nil, nil
 }
 
 // Semtimedop handles: semop(int semid, struct sembuf *sops, size_t nsops, const struct timespec *timeout)
@@ -56,7 +57,7 @@ func Semtimedop(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sy
 		return Semop(t, args)
 	}
 
-	id := args[0].Int()
+	id := ipc.ID(args[0].Int())
 	sembufAddr := args[1].Pointer()
 	nsops := args[2].SizeT()
 	timespecAddr := args[3].Pointer()
@@ -91,7 +92,7 @@ func Semtimedop(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sy
 
 // Semop handles: semop(int semid, struct sembuf *sops, size_t nsops)
 func Semop(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
-	id := args[0].Int()
+	id := ipc.ID(args[0].Int())
 	sembufAddr := args[1].Pointer()
 	nsops := args[2].SizeT()
 
@@ -109,7 +110,7 @@ func Semop(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
 	return 0, nil, semTimedOp(t, id, ops, false, time.Second)
 }
 
-func semTimedOp(t *kernel.Task, id int32, ops []linux.Sembuf, haveTimeout bool, timeout time.Duration) error {
+func semTimedOp(t *kernel.Task, id ipc.ID, ops []linux.Sembuf, haveTimeout bool, timeout time.Duration) error {
 	set := t.IPCNamespace().SemaphoreRegistry().FindByID(id)
 
 	if set == nil {
@@ -131,7 +132,7 @@ func semTimedOp(t *kernel.Task, id int32, ops []linux.Sembuf, haveTimeout bool,
 
 // Semctl handles: semctl(int semid, int semnum, int cmd, ...)
 func Semctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
-	id := args[0].Int()
+	id := ipc.ID(args[0].Int())
 	num := args[1].Int()
 	cmd := args[2].Int()
 
@@ -210,7 +211,7 @@ func Semctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
 	case linux.SEM_STAT:
 		arg := args[3].Pointer()
 		// id is an index in SEM_STAT.
-		semid, ds, err := semStat(t, id)
+		semid, ds, err := semStat(t, int32(id))
 		if err != nil {
 			return 0, nil, err
 		}
@@ -222,7 +223,7 @@ func Semctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
 	case linux.SEM_STAT_ANY:
 		arg := args[3].Pointer()
 		// id is an index in SEM_STAT.
-		semid, ds, err := semStatAny(t, id)
+		semid, ds, err := semStatAny(t, int32(id))
 		if err != nil {
 			return 0, nil, err
 		}
@@ -236,13 +237,13 @@ func Semctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
 	}
 }
 
-func remove(t *kernel.Task, id int32) error {
+func remove(t *kernel.Task, id ipc.ID) error {
 	r := t.IPCNamespace().SemaphoreRegistry()
 	creds := auth.CredentialsFromContext(t)
 	return r.RemoveID(id, creds)
 }
 
-func ipcSet(t *kernel.Task, id int32, uid auth.UID, gid auth.GID, perms fs.FilePermissions) error {
+func ipcSet(t *kernel.Task, id ipc.ID, uid auth.UID, gid auth.GID, perms fs.FilePermissions) error {
 	r := t.IPCNamespace().SemaphoreRegistry()
 	set := r.FindByID(id)
 	if set == nil {
@@ -262,7 +263,7 @@ func ipcSet(t *kernel.Task, id int32, uid auth.UID, gid auth.GID, perms fs.FileP
 	return set.Change(t, creds, owner, perms)
 }
 
-func ipcStat(t *kernel.Task, id int32) (*linux.SemidDS, error) {
+func ipcStat(t *kernel.Task, id ipc.ID) (*linux.SemidDS, error) {
 	r := t.IPCNamespace().SemaphoreRegistry()
 	set := r.FindByID(id)
 	if set == nil {
@@ -283,7 +284,7 @@ func semStat(t *kernel.Task, index int32) (int32, *linux.SemidDS, error) {
 	if err != nil {
 		return 0, ds, err
 	}
-	return set.ID, ds, nil
+	return int32(set.ID()), ds, nil
 }
 
 func semStatAny(t *kernel.Task, index int32) (int32, *linux.SemidDS, error) {
@@ -296,10 +297,10 @@ func semStatAny(t *kernel.Task, index int32) (int32, *linux.SemidDS, error) {
 	if err != nil {
 		return 0, ds, err
 	}
-	return set.ID, ds, nil
+	return int32(set.ID()), ds, nil
 }
 
-func setVal(t *kernel.Task, id int32, num int32, val int16) error {
+func setVal(t *kernel.Task, id ipc.ID, num int32, val int16) error {
 	r := t.IPCNamespace().SemaphoreRegistry()
 	set := r.FindByID(id)
 	if set == nil {
@@ -310,7 +311,7 @@ func setVal(t *kernel.Task, id int32, num int32, val int16) error {
 	return set.SetVal(t, num, val, creds, int32(pid))
 }
 
-func setValAll(t *kernel.Task, id int32, array hostarch.Addr) error {
+func setValAll(t *kernel.Task, id ipc.ID, array hostarch.Addr) error {
 	r := t.IPCNamespace().SemaphoreRegistry()
 	set := r.FindByID(id)
 	if set == nil {
@@ -325,7 +326,7 @@ func setValAll(t *kernel.Task, id int32, array hostarch.Addr) error {
 	return set.SetValAll(t, vals, creds, int32(pid))
 }
 
-func getVal(t *kernel.Task, id int32, num int32) (int16, error) {
+func getVal(t *kernel.Task, id ipc.ID, num int32) (int16, error) {
 	r := t.IPCNamespace().SemaphoreRegistry()
 	set := r.FindByID(id)
 	if set == nil {
@@ -335,7 +336,7 @@ func getVal(t *kernel.Task, id int32, num int32) (int16, error) {
 	return set.GetVal(num, creds)
 }
 
-func getValAll(t *kernel.Task, id int32, array hostarch.Addr) error {
+func getValAll(t *kernel.Task, id ipc.ID, array hostarch.Addr) error {
 	r := t.IPCNamespace().SemaphoreRegistry()
 	set := r.FindByID(id)
 	if set == nil {
@@ -350,7 +351,7 @@ func getValAll(t *kernel.Task, id int32, array hostarch.Addr) error {
 	return err
 }
 
-func getPID(t *kernel.Task, id int32, num int32) (int32, error) {
+func getPID(t *kernel.Task, id ipc.ID, num int32) (int32, error) {
 	r := t.IPCNamespace().SemaphoreRegistry()
 	set := r.FindByID(id)
 	if set == nil {
@@ -369,7 +370,7 @@ func getPID(t *kernel.Task, id int32, num int32) (int32, error) {
 	return int32(tg.ID()), nil
 }
 
-func getZCnt(t *kernel.Task, id int32, num int32) (uint16, error) {
+func getZCnt(t *kernel.Task, id ipc.ID, num int32) (uint16, error) {
 	r := t.IPCNamespace().SemaphoreRegistry()
 	set := r.FindByID(id)
 	if set == nil {
@@ -379,7 +380,7 @@ func getZCnt(t *kernel.Task, id int32, num int32) (uint16, error) {
 	return set.CountZeroWaiters(num, creds)
 }
 
-func getNCnt(t *kernel.Task, id int32, num int32) (uint16, error) {
+func getNCnt(t *kernel.Task, id ipc.ID, num int32) (uint16, error) {
 	r := t.IPCNamespace().SemaphoreRegistry()
 	set := r.FindByID(id)
 	if set == nil {
diff --git a/pkg/sentry/syscalls/linux/sys_shm.go b/pkg/sentry/syscalls/linux/sys_shm.go
index 3e3a952ce..840540506 100644
--- a/pkg/sentry/syscalls/linux/sys_shm.go
+++ b/pkg/sentry/syscalls/linux/sys_shm.go
@@ -19,12 +19,13 @@ import (
 	"gvisor.dev/gvisor/pkg/errors/linuxerr"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sentry/kernel/ipc"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/shm"
 )
 
 // Shmget implements shmget(2).
 func Shmget(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
-	key := shm.Key(args[0].Int())
+	key := ipc.Key(args[0].Int())
 	size := uint64(args[1].SizeT())
 	flag := args[2].Int()
 
@@ -40,13 +41,13 @@ func Shmget(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
 		return 0, nil, err
 	}
 	defer segment.DecRef(t)
-	return uintptr(segment.ID), nil, nil
+	return uintptr(segment.ID()), nil, nil
 }
 
 // findSegment retrives a shm segment by the given id.
 //
 // findSegment returns a reference on Shm.
-func findSegment(t *kernel.Task, id shm.ID) (*shm.Shm, error) {
+func findSegment(t *kernel.Task, id ipc.ID) (*shm.Shm, error) {
 	r := t.IPCNamespace().ShmRegistry()
 	segment := r.FindByID(id)
 	if segment == nil {
@@ -58,7 +59,7 @@ func findSegment(t *kernel.Task, id shm.ID) (*shm.Shm, error) {
 
 // Shmat implements shmat(2).
 func Shmat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
-	id := shm.ID(args[0].Int())
+	id := ipc.ID(args[0].Int())
 	addr := args[1].Pointer()
 	flag := args[2].Int()
 
@@ -89,7 +90,7 @@ func Shmdt(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
 
 // Shmctl implements shmctl(2).
 func Shmctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
-	id := shm.ID(args[0].Int())
+	id := ipc.ID(args[0].Int())
 	cmd := args[1].Int()
 	buf := args[2].Pointer()