From 1e56a2f9a29ff72eada493bf024a4e3fd5a963b6 Mon Sep 17 00:00:00 2001
From: Jing Chen <chjing@google.com>
Date: Tue, 15 Dec 2020 16:03:41 -0800
Subject: Implement command SEM_INFO and SEM_STAT for semctl.

PiperOrigin-RevId: 347711998
---
 pkg/sentry/syscalls/linux/linux64.go |  4 ++--
 pkg/sentry/syscalls/linux/sys_sem.go | 35 ++++++++++++++++++++++++++++++++---
 2 files changed, 34 insertions(+), 5 deletions(-)

(limited to 'pkg/sentry/syscalls')

diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go
index cff442846..b815e498f 100644
--- a/pkg/sentry/syscalls/linux/linux64.go
+++ b/pkg/sentry/syscalls/linux/linux64.go
@@ -118,7 +118,7 @@ var AMD64 = &kernel.SyscallTable{
 		63:  syscalls.Supported("uname", Uname),
 		64:  syscalls.Supported("semget", Semget),
 		65:  syscalls.PartiallySupported("semop", Semop, "Option SEM_UNDO not supported.", nil),
-		66:  syscalls.PartiallySupported("semctl", Semctl, "Options SEM_INFO, SEM_STAT, SEM_STAT_ANY not supported.", nil),
+		66:  syscalls.PartiallySupported("semctl", Semctl, "Options SEM_STAT_ANY not supported.", nil),
 		67:  syscalls.Supported("shmdt", Shmdt),
 		68:  syscalls.ErrorWithEvent("msgget", syserror.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
 		69:  syscalls.ErrorWithEvent("msgsnd", syserror.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
@@ -619,7 +619,7 @@ var ARM64 = &kernel.SyscallTable{
 		188: syscalls.ErrorWithEvent("msgrcv", syserror.ENOSYS, "", []string{"gvisor.dev/issue/135"}),          // TODO(b/29354921)
 		189: syscalls.ErrorWithEvent("msgsnd", syserror.ENOSYS, "", []string{"gvisor.dev/issue/135"}),          // TODO(b/29354921)
 		190: syscalls.Supported("semget", Semget),
-		191: syscalls.PartiallySupported("semctl", Semctl, "Options SEM_INFO, SEM_STAT, SEM_STAT_ANY not supported.", nil),
+		191: syscalls.PartiallySupported("semctl", Semctl, "Options SEM_STAT_ANY not supported.", nil),
 		192: syscalls.ErrorWithEvent("semtimedop", syserror.ENOSYS, "", []string{"gvisor.dev/issue/137"}),
 		193: syscalls.PartiallySupported("semop", Semop, "Option SEM_UNDO not supported.", nil),
 		194: syscalls.PartiallySupported("shmget", Shmget, "Option SHM_HUGETLB is not supported.", nil),
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)
-- 
cgit v1.2.3