Merge release-20201130.0-36-ga78cef0ed (automated)

5 files changed, 177 insertions, 4 deletions

diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go
index 3ccd566d4..aa0bfcc6b 100644
--- a/pkg/abi/linux/linux_abi_autogen_unsafe.go
+++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go
@@ -67,6 +67,7 @@ var _ marshal.Marshallable = (*RSeqCriticalSection)(nil)
 var _ marshal.Marshallable = (*RobustListHead)(nil)
 var _ marshal.Marshallable = (*Rusage)(nil)
 var _ marshal.Marshallable = (*SeccompData)(nil)
+var _ marshal.Marshallable = (*SemInfo)(nil)
 var _ marshal.Marshallable = (*Sembuf)(nil)
 var _ marshal.Marshallable = (*ShmInfo)(nil)
 var _ marshal.Marshallable = (*ShmParams)(nil)
@@ -6882,6 +6883,131 @@ func UnmarshalUnsafeSembufSlice(dst []Sembuf, src []byte) (int, error) {
 }
 
 // SizeBytes implements marshal.Marshallable.SizeBytes.
+func (s *SemInfo) SizeBytes() int {
+    return 40
+}
+
+// MarshalBytes implements marshal.Marshallable.MarshalBytes.
+func (s *SemInfo) MarshalBytes(dst []byte) {
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.SemMap))
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.SemMni))
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.SemMns))
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.SemMnu))
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.SemMsl))
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.SemOpm))
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.SemUme))
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.SemUsz))
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.SemVmx))
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.SemAem))
+    dst = dst[4:]
+}
+
+// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.
+func (s *SemInfo) UnmarshalBytes(src []byte) {
+    s.SemMap = uint32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    s.SemMni = uint32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    s.SemMns = uint32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    s.SemMnu = uint32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    s.SemMsl = uint32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    s.SemOpm = uint32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    s.SemUme = uint32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    s.SemUsz = uint32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    s.SemVmx = uint32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    s.SemAem = uint32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+}
+
+// Packed implements marshal.Marshallable.Packed.
+//go:nosplit
+func (s *SemInfo) Packed() bool {
+    return true
+}
+
+// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
+func (s *SemInfo) MarshalUnsafe(dst []byte) {
+    safecopy.CopyIn(dst, unsafe.Pointer(s))
+}
+
+// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
+func (s *SemInfo) UnmarshalUnsafe(src []byte) {
+    safecopy.CopyOut(unsafe.Pointer(s), src)
+}
+
+// CopyOutN implements marshal.Marshallable.CopyOutN.
+//go:nosplit
+func (s *SemInfo) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
+    // Construct a slice backed by dst's underlying memory.
+    var buf []byte
+    hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
+    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s)))
+    hdr.Len = s.SizeBytes()
+    hdr.Cap = s.SizeBytes()
+
+    length, err := cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
+    // Since we bypassed the compiler's escape analysis, indicate that s
+    // must live until the use above.
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
+    return length, err
+}
+
+// CopyOut implements marshal.Marshallable.CopyOut.
+//go:nosplit
+func (s *SemInfo) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+    return s.CopyOutN(cc, addr, s.SizeBytes())
+}
+
+// CopyIn implements marshal.Marshallable.CopyIn.
+//go:nosplit
+func (s *SemInfo) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+    // Construct a slice backed by dst's underlying memory.
+    var buf []byte
+    hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
+    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s)))
+    hdr.Len = s.SizeBytes()
+    hdr.Cap = s.SizeBytes()
+
+    length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
+    // Since we bypassed the compiler's escape analysis, indicate that s
+    // must live until the use above.
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
+    return length, err
+}
+
+// WriteTo implements io.WriterTo.WriteTo.
+func (s *SemInfo) WriteTo(writer io.Writer) (int64, error) {
+    // Construct a slice backed by dst's underlying memory.
+    var buf []byte
+    hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
+    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s)))
+    hdr.Len = s.SizeBytes()
+    hdr.Cap = s.SizeBytes()
+
+    length, err := writer.Write(buf)
+    // Since we bypassed the compiler's escape analysis, indicate that s
+    // must live until the use above.
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
+    return int64(length), err
+}
+
+// SizeBytes implements marshal.Marshallable.SizeBytes.
 func (s *ShmidDS) SizeBytes() int {
     return 40 +
         (*IPCPerm)(nil).SizeBytes() +
diff --git a/pkg/abi/linux/sem.go b/pkg/abi/linux/sem.go
index 167d2ff74..0adff8dff 100644
--- a/pkg/abi/linux/sem.go
+++ b/pkg/abi/linux/sem.go
@@ -41,6 +41,12 @@ const (
 	SEMMNS = SEMMNI * SEMMSL
 	SEMOPM = 500
 	SEMVMX = 32767
+	SEMAEM = SEMVMX
+
+	// followings are unused in kernel
+	SEMUME = SEMOPM
+	SEMMNU = SEMMNS
+	SEMMAP = SEMMNS
 )
 
 const SEM_UNDO = 0x1000
@@ -53,3 +59,21 @@ type Sembuf struct {
 	SemOp  int16
 	SemFlg int16
 }
+
+// SemInfo is equivalent to struct seminfo.
+//
+// Source: include/uapi/linux/sem.h
+//
+// +marshal
+type SemInfo struct {
+	SemMap uint32
+	SemMni uint32
+	SemMns uint32
+	SemMnu uint32
+	SemMsl uint32
+	SemOpm uint32
+	SemUme uint32
+	SemUsz uint32
+	SemVmx uint32
+	SemAem uint32
+}
diff --git a/pkg/sentry/kernel/semaphore/semaphore.go b/pkg/sentry/kernel/semaphore/semaphore.go
index 335be8edd..31198d772 100644
--- a/pkg/sentry/kernel/semaphore/semaphore.go
+++ b/pkg/sentry/kernel/semaphore/semaphore.go
@@ -176,6 +176,22 @@ func (r *Registry) FindOrCreate(ctx context.Context, key, nsems int32, mode linu
 	return r.newSet(ctx, key, owner, owner, perms, nsems)
 }
 
+// IPCInfo returns information about system-wide semaphore limits and parameters.
+func (r *Registry) IPCInfo() *linux.SemInfo {
+	return &linux.SemInfo{
+		SemMap: linux.SEMMAP,
+		SemMni: linux.SEMMNI,
+		SemMns: linux.SEMMNS,
+		SemMnu: linux.SEMMNU,
+		SemMsl: linux.SEMMSL,
+		SemOpm: linux.SEMOPM,
+		SemUme: linux.SEMUME,
+		SemUsz: 0, // SemUsz not supported.
+		SemVmx: linux.SEMVMX,
+		SemAem: linux.SEMAEM,
+	}
+}
+
 // RemoveID removes set with give 'id' from the registry and marks the set as
 // dead. All waiters will be awakened and fail.
 func (r *Registry) RemoveID(id int32, creds *auth.Credentials) error {
diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go
index bb1f715e2..cff442846 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 IPC_INFO, SEM_INFO, SEM_STAT, SEM_STAT_ANY not supported.", nil),
+		66:  syscalls.PartiallySupported("semctl", Semctl, "Options SEM_INFO, SEM_STAT, 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 IPC_INFO, SEM_INFO, SEM_STAT, SEM_STAT_ANY not supported.", nil),
+		191: syscalls.PartiallySupported("semctl", Semctl, "Options SEM_INFO, SEM_STAT, 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 e383a0a87..a1601676f 100644
--- a/pkg/sentry/syscalls/linux/sys_sem.go
+++ b/pkg/sentry/syscalls/linux/sys_sem.go
@@ -146,8 +146,15 @@ func Semctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
 		v, err := getNCnt(t, id, num)
 		return uintptr(v), nil, err
 
-	case linux.IPC_INFO,
-		linux.SEM_INFO,
+	case linux.IPC_INFO:
+		buf := args[3].Pointer()
+		r := t.IPCNamespace().SemaphoreRegistry()
+		info := r.IPCInfo()
+		_, err := info.CopyOut(t, buf)
+		// TODO(gvisor.dev/issue/137): Return the index of the highest used entry.
+		return 0, nil, err
+
+	case linux.SEM_INFO,
 		linux.SEM_STAT,
 		linux.SEM_STAT_ANY: