Implement command SEM_INFO and SEM_STAT for semctl.

PiperOrigin-RevId: 347711998

1 files changed, 32 insertions, 3 deletions

diff --git a/pkg/sentry/syscalls/linux/sys_sem.go b/pkg/sentry/syscalls/linux/sys_sem.go
index a62a6b3b5..1166cd7bb 100644
--- a/pkg/sentry/syscalls/linux/sys_sem.go
+++ b/pkg/sentry/syscalls/linux/sys_sem.go
@@ -155,10 +155,28 @@ func Semctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
 		}
 		return uintptr(r.HighestIndex()), nil, nil
 
-	case linux.SEM_INFO,
-		linux.SEM_STAT,
-		linux.SEM_STAT_ANY:
+	case linux.SEM_INFO:
+		buf := args[3].Pointer()
+		r := t.IPCNamespace().SemaphoreRegistry()
+		info := r.SemInfo()
+		if _, err := info.CopyOut(t, buf); err != nil {
+			return 0, nil, err
+		}
+		return uintptr(r.HighestIndex()), nil, nil
 
+	case linux.SEM_STAT:
+		arg := args[3].Pointer()
+		// id is an index in SEM_STAT.
+		semid, ds, err := semStat(t, id)
+		if err != nil {
+			return 0, nil, err
+		}
+		if _, err := ds.CopyOut(t, arg); err != nil {
+			return 0, nil, err
+		}
+		return uintptr(semid), nil, err
+
+	case linux.SEM_STAT_ANY:
 		t.Kernel().EmitUnimplementedEvent(t)
 		fallthrough
 
@@ -203,6 +221,17 @@ func ipcStat(t *kernel.Task, id int32) (*linux.SemidDS, error) {
 	return set.GetStat(creds)
 }
 
+func semStat(t *kernel.Task, index int32) (int32, *linux.SemidDS, error) {
+	r := t.IPCNamespace().SemaphoreRegistry()
+	set := r.FindByIndex(index)
+	if set == nil {
+		return 0, nil, syserror.EINVAL
+	}
+	creds := auth.CredentialsFromContext(t)
+	ds, err := set.GetStat(creds)
+	return set.ID, ds, err
+}
+
 func setVal(t *kernel.Task, id int32, num int32, val int16) error {
 	r := t.IPCNamespace().SemaphoreRegistry()
 	set := r.FindByID(id)