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-rw-r--r--pkg/sentry/syscalls/linux/sys_file.go39
-rw-r--r--pkg/sentry/syscalls/linux/sys_splice.go8
-rw-r--r--pkg/sentry/syscalls/linux/sys_xattr.go12
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/BUILD5
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/fd.go2
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/inotify.go134
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/lock.go64
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/mount.go145
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/read_write.go36
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/splice.go291
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/vfs2.go18
11 files changed, 711 insertions, 43 deletions
diff --git a/pkg/sentry/syscalls/linux/sys_file.go b/pkg/sentry/syscalls/linux/sys_file.go
index 35a98212a..8347617bd 100644
--- a/pkg/sentry/syscalls/linux/sys_file.go
+++ b/pkg/sentry/syscalls/linux/sys_file.go
@@ -998,9 +998,6 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
return 0, nil, err
}
- // The lock uid is that of the Task's FDTable.
- lockUniqueID := lock.UniqueID(t.FDTable().ID())
-
// These locks don't block; execute the non-blocking operation using the inode's lock
// context directly.
switch flock.Type {
@@ -1010,12 +1007,12 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
}
if cmd == linux.F_SETLK {
// Non-blocking lock, provide a nil lock.Blocker.
- if !file.Dirent.Inode.LockCtx.Posix.LockRegion(lockUniqueID, lock.ReadLock, rng, nil) {
+ if !file.Dirent.Inode.LockCtx.Posix.LockRegion(t.FDTable(), lock.ReadLock, rng, nil) {
return 0, nil, syserror.EAGAIN
}
} else {
// Blocking lock, pass in the task to satisfy the lock.Blocker interface.
- if !file.Dirent.Inode.LockCtx.Posix.LockRegion(lockUniqueID, lock.ReadLock, rng, t) {
+ if !file.Dirent.Inode.LockCtx.Posix.LockRegion(t.FDTable(), lock.ReadLock, rng, t) {
return 0, nil, syserror.EINTR
}
}
@@ -1026,18 +1023,18 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
}
if cmd == linux.F_SETLK {
// Non-blocking lock, provide a nil lock.Blocker.
- if !file.Dirent.Inode.LockCtx.Posix.LockRegion(lockUniqueID, lock.WriteLock, rng, nil) {
+ if !file.Dirent.Inode.LockCtx.Posix.LockRegion(t.FDTable(), lock.WriteLock, rng, nil) {
return 0, nil, syserror.EAGAIN
}
} else {
// Blocking lock, pass in the task to satisfy the lock.Blocker interface.
- if !file.Dirent.Inode.LockCtx.Posix.LockRegion(lockUniqueID, lock.WriteLock, rng, t) {
+ if !file.Dirent.Inode.LockCtx.Posix.LockRegion(t.FDTable(), lock.WriteLock, rng, t) {
return 0, nil, syserror.EINTR
}
}
return 0, nil, nil
case linux.F_UNLCK:
- file.Dirent.Inode.LockCtx.Posix.UnlockRegion(lockUniqueID, rng)
+ file.Dirent.Inode.LockCtx.Posix.UnlockRegion(t.FDTable(), rng)
return 0, nil, nil
default:
return 0, nil, syserror.EINVAL
@@ -2157,22 +2154,6 @@ func Flock(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
nonblocking := operation&linux.LOCK_NB != 0
operation &^= linux.LOCK_NB
- // flock(2):
- // Locks created by flock() are associated with an open file table entry. This means that
- // duplicate file descriptors (created by, for example, fork(2) or dup(2)) refer to the
- // same lock, and this lock may be modified or released using any of these descriptors. Furthermore,
- // the lock is released either by an explicit LOCK_UN operation on any of these duplicate
- // descriptors, or when all such descriptors have been closed.
- //
- // If a process uses open(2) (or similar) to obtain more than one descriptor for the same file,
- // these descriptors are treated independently by flock(). An attempt to lock the file using
- // one of these file descriptors may be denied by a lock that the calling process has already placed via
- // another descriptor.
- //
- // We use the File UniqueID as the lock UniqueID because it needs to reference the same lock across dup(2)
- // and fork(2).
- lockUniqueID := lock.UniqueID(file.UniqueID)
-
// A BSD style lock spans the entire file.
rng := lock.LockRange{
Start: 0,
@@ -2183,29 +2164,29 @@ func Flock(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
case linux.LOCK_EX:
if nonblocking {
// Since we're nonblocking we pass a nil lock.Blocker implementation.
- if !file.Dirent.Inode.LockCtx.BSD.LockRegion(lockUniqueID, lock.WriteLock, rng, nil) {
+ if !file.Dirent.Inode.LockCtx.BSD.LockRegion(file, lock.WriteLock, rng, nil) {
return 0, nil, syserror.EWOULDBLOCK
}
} else {
// Because we're blocking we will pass the task to satisfy the lock.Blocker interface.
- if !file.Dirent.Inode.LockCtx.BSD.LockRegion(lockUniqueID, lock.WriteLock, rng, t) {
+ if !file.Dirent.Inode.LockCtx.BSD.LockRegion(file, lock.WriteLock, rng, t) {
return 0, nil, syserror.EINTR
}
}
case linux.LOCK_SH:
if nonblocking {
// Since we're nonblocking we pass a nil lock.Blocker implementation.
- if !file.Dirent.Inode.LockCtx.BSD.LockRegion(lockUniqueID, lock.ReadLock, rng, nil) {
+ if !file.Dirent.Inode.LockCtx.BSD.LockRegion(file, lock.ReadLock, rng, nil) {
return 0, nil, syserror.EWOULDBLOCK
}
} else {
// Because we're blocking we will pass the task to satisfy the lock.Blocker interface.
- if !file.Dirent.Inode.LockCtx.BSD.LockRegion(lockUniqueID, lock.ReadLock, rng, t) {
+ if !file.Dirent.Inode.LockCtx.BSD.LockRegion(file, lock.ReadLock, rng, t) {
return 0, nil, syserror.EINTR
}
}
case linux.LOCK_UN:
- file.Dirent.Inode.LockCtx.BSD.UnlockRegion(lockUniqueID, rng)
+ file.Dirent.Inode.LockCtx.BSD.UnlockRegion(file, rng)
default:
// flock(2): EINVAL operation is invalid.
return 0, nil, syserror.EINVAL
diff --git a/pkg/sentry/syscalls/linux/sys_splice.go b/pkg/sentry/syscalls/linux/sys_splice.go
index df0d0f461..77c78889d 100644
--- a/pkg/sentry/syscalls/linux/sys_splice.go
+++ b/pkg/sentry/syscalls/linux/sys_splice.go
@@ -16,7 +16,6 @@ package linux
import (
"gvisor.dev/gvisor/pkg/abi/linux"
- "gvisor.dev/gvisor/pkg/log"
"gvisor.dev/gvisor/pkg/sentry/arch"
"gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sentry/kernel"
@@ -26,7 +25,6 @@ import (
// doSplice implements a blocking splice operation.
func doSplice(t *kernel.Task, outFile, inFile *fs.File, opts fs.SpliceOpts, nonBlocking bool) (int64, error) {
- log.Infof("NLAC: doSplice opts: %+v", opts)
if opts.Length < 0 || opts.SrcStart < 0 || opts.DstStart < 0 || (opts.SrcStart+opts.Length < 0) {
return 0, syserror.EINVAL
}
@@ -82,6 +80,12 @@ func doSplice(t *kernel.Task, outFile, inFile *fs.File, opts fs.SpliceOpts, nonB
}
}
+ if total > 0 {
+ // On Linux, inotify behavior is not very consistent with splice(2). We try
+ // our best to emulate Linux for very basic calls to splice, where for some
+ // reason, events are generated for output files, but not input files.
+ outFile.Dirent.InotifyEvent(linux.IN_MODIFY, 0)
+ }
return total, err
}
diff --git a/pkg/sentry/syscalls/linux/sys_xattr.go b/pkg/sentry/syscalls/linux/sys_xattr.go
index 2de5e3422..c24946160 100644
--- a/pkg/sentry/syscalls/linux/sys_xattr.go
+++ b/pkg/sentry/syscalls/linux/sys_xattr.go
@@ -207,7 +207,11 @@ func setXattr(t *kernel.Task, d *fs.Dirent, nameAddr, valueAddr usermem.Addr, si
return syserror.EOPNOTSUPP
}
- return d.Inode.SetXattr(t, d, name, value, flags)
+ if err := d.Inode.SetXattr(t, d, name, value, flags); err != nil {
+ return err
+ }
+ d.InotifyEvent(linux.IN_ATTRIB, 0)
+ return nil
}
func copyInXattrName(t *kernel.Task, nameAddr usermem.Addr) (string, error) {
@@ -418,7 +422,11 @@ func removeXattr(t *kernel.Task, d *fs.Dirent, nameAddr usermem.Addr) error {
return syserror.EOPNOTSUPP
}
- return d.Inode.RemoveXattr(t, d, name)
+ if err := d.Inode.RemoveXattr(t, d, name); err != nil {
+ return err
+ }
+ d.InotifyEvent(linux.IN_ATTRIB, 0)
+ return nil
}
// LINT.ThenChange(vfs2/xattr.go)
diff --git a/pkg/sentry/syscalls/linux/vfs2/BUILD b/pkg/sentry/syscalls/linux/vfs2/BUILD
index f882ef840..9f93f4354 100644
--- a/pkg/sentry/syscalls/linux/vfs2/BUILD
+++ b/pkg/sentry/syscalls/linux/vfs2/BUILD
@@ -12,9 +12,12 @@ go_library(
"filesystem.go",
"fscontext.go",
"getdents.go",
+ "inotify.go",
"ioctl.go",
+ "lock.go",
"memfd.go",
"mmap.go",
+ "mount.go",
"path.go",
"pipe.go",
"poll.go",
@@ -22,6 +25,7 @@ go_library(
"setstat.go",
"signal.go",
"socket.go",
+ "splice.go",
"stat.go",
"stat_amd64.go",
"stat_arm64.go",
@@ -39,6 +43,7 @@ go_library(
"//pkg/fspath",
"//pkg/gohacks",
"//pkg/sentry/arch",
+ "//pkg/sentry/fs/lock",
"//pkg/sentry/fsbridge",
"//pkg/sentry/fsimpl/eventfd",
"//pkg/sentry/fsimpl/pipefs",
diff --git a/pkg/sentry/syscalls/linux/vfs2/fd.go b/pkg/sentry/syscalls/linux/vfs2/fd.go
index ca0f7fd1e..6006758a5 100644
--- a/pkg/sentry/syscalls/linux/vfs2/fd.go
+++ b/pkg/sentry/syscalls/linux/vfs2/fd.go
@@ -168,7 +168,7 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
err := tmpfs.AddSeals(file, args[2].Uint())
return 0, nil, err
default:
- // TODO(gvisor.dev/issue/1623): Everything else is not yet supported.
+ // TODO(gvisor.dev/issue/2920): Everything else is not yet supported.
return 0, nil, syserror.EINVAL
}
}
diff --git a/pkg/sentry/syscalls/linux/vfs2/inotify.go b/pkg/sentry/syscalls/linux/vfs2/inotify.go
new file mode 100644
index 000000000..7d50b6a16
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/inotify.go
@@ -0,0 +1,134 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+)
+
+const allFlags = linux.IN_NONBLOCK | linux.IN_CLOEXEC
+
+// InotifyInit1 implements the inotify_init1() syscalls.
+func InotifyInit1(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ flags := args[0].Int()
+ if flags&^allFlags != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ ino, err := vfs.NewInotifyFD(t, t.Kernel().VFS(), uint32(flags))
+ if err != nil {
+ return 0, nil, err
+ }
+ defer ino.DecRef()
+
+ fd, err := t.NewFDFromVFS2(0, ino, kernel.FDFlags{
+ CloseOnExec: flags&linux.IN_CLOEXEC != 0,
+ })
+
+ if err != nil {
+ return 0, nil, err
+ }
+
+ return uintptr(fd), nil, nil
+}
+
+// InotifyInit implements the inotify_init() syscalls.
+func InotifyInit(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ args[0].Value = 0
+ return InotifyInit1(t, args)
+}
+
+// fdToInotify resolves an fd to an inotify object. If successful, the file will
+// have an extra ref and the caller is responsible for releasing the ref.
+func fdToInotify(t *kernel.Task, fd int32) (*vfs.Inotify, *vfs.FileDescription, error) {
+ f := t.GetFileVFS2(fd)
+ if f == nil {
+ // Invalid fd.
+ return nil, nil, syserror.EBADF
+ }
+
+ ino, ok := f.Impl().(*vfs.Inotify)
+ if !ok {
+ // Not an inotify fd.
+ f.DecRef()
+ return nil, nil, syserror.EINVAL
+ }
+
+ return ino, f, nil
+}
+
+// InotifyAddWatch implements the inotify_add_watch() syscall.
+func InotifyAddWatch(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ mask := args[2].Uint()
+
+ // "EINVAL: The given event mask contains no valid events."
+ // -- inotify_add_watch(2)
+ if validBits := mask & linux.ALL_INOTIFY_BITS; validBits == 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // "IN_DONT_FOLLOW: Don't dereference pathname if it is a symbolic link."
+ // -- inotify(7)
+ follow := followFinalSymlink
+ if mask&linux.IN_DONT_FOLLOW == 0 {
+ follow = nofollowFinalSymlink
+ }
+
+ ino, f, err := fdToInotify(t, fd)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer f.DecRef()
+
+ path, err := copyInPath(t, addr)
+ if err != nil {
+ return 0, nil, err
+ }
+ if mask&linux.IN_ONLYDIR != 0 {
+ path.Dir = true
+ }
+ tpop, err := getTaskPathOperation(t, linux.AT_FDCWD, path, disallowEmptyPath, follow)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer tpop.Release()
+ d, err := t.Kernel().VFS().GetDentryAt(t, t.Credentials(), &tpop.pop, &vfs.GetDentryOptions{})
+ if err != nil {
+ return 0, nil, err
+ }
+ defer d.DecRef()
+
+ fd = ino.AddWatch(d.Dentry(), mask)
+ return uintptr(fd), nil, err
+}
+
+// InotifyRmWatch implements the inotify_rm_watch() syscall.
+func InotifyRmWatch(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ wd := args[1].Int()
+
+ ino, f, err := fdToInotify(t, fd)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer f.DecRef()
+ return 0, nil, ino.RmWatch(wd)
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/lock.go b/pkg/sentry/syscalls/linux/vfs2/lock.go
new file mode 100644
index 000000000..bf19028c4
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/lock.go
@@ -0,0 +1,64 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/fs/lock"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/syserror"
+)
+
+// Flock implements linux syscall flock(2).
+func Flock(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ operation := args[1].Int()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ // flock(2): EBADF fd is not an open file descriptor.
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ nonblocking := operation&linux.LOCK_NB != 0
+ operation &^= linux.LOCK_NB
+
+ var blocker lock.Blocker
+ if !nonblocking {
+ blocker = t
+ }
+
+ switch operation {
+ case linux.LOCK_EX:
+ if err := file.LockBSD(t, lock.WriteLock, blocker); err != nil {
+ return 0, nil, err
+ }
+ case linux.LOCK_SH:
+ if err := file.LockBSD(t, lock.ReadLock, blocker); err != nil {
+ return 0, nil, err
+ }
+ case linux.LOCK_UN:
+ if err := file.UnlockBSD(t); err != nil {
+ return 0, nil, err
+ }
+ default:
+ // flock(2): EINVAL operation is invalid.
+ return 0, nil, syserror.EINVAL
+ }
+
+ return 0, nil, nil
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/mount.go b/pkg/sentry/syscalls/linux/vfs2/mount.go
new file mode 100644
index 000000000..adeaa39cc
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/mount.go
@@ -0,0 +1,145 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+)
+
+// Mount implements Linux syscall mount(2).
+func Mount(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ sourceAddr := args[0].Pointer()
+ targetAddr := args[1].Pointer()
+ typeAddr := args[2].Pointer()
+ flags := args[3].Uint64()
+ dataAddr := args[4].Pointer()
+
+ // For null-terminated strings related to mount(2), Linux copies in at most
+ // a page worth of data. See fs/namespace.c:copy_mount_string().
+ fsType, err := t.CopyInString(typeAddr, usermem.PageSize)
+ if err != nil {
+ return 0, nil, err
+ }
+ source, err := t.CopyInString(sourceAddr, usermem.PageSize)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ targetPath, err := copyInPath(t, targetAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ data := ""
+ if dataAddr != 0 {
+ // In Linux, a full page is always copied in regardless of null
+ // character placement, and the address is passed to each file system.
+ // Most file systems always treat this data as a string, though, and so
+ // do all of the ones we implement.
+ data, err = t.CopyInString(dataAddr, usermem.PageSize)
+ if err != nil {
+ return 0, nil, err
+ }
+ }
+
+ // Ignore magic value that was required before Linux 2.4.
+ if flags&linux.MS_MGC_MSK == linux.MS_MGC_VAL {
+ flags = flags &^ linux.MS_MGC_MSK
+ }
+
+ // Must have CAP_SYS_ADMIN in the current mount namespace's associated user
+ // namespace.
+ creds := t.Credentials()
+ if !creds.HasCapabilityIn(linux.CAP_SYS_ADMIN, t.MountNamespaceVFS2().Owner) {
+ return 0, nil, syserror.EPERM
+ }
+
+ const unsupportedOps = linux.MS_REMOUNT | linux.MS_BIND |
+ linux.MS_SHARED | linux.MS_PRIVATE | linux.MS_SLAVE |
+ linux.MS_UNBINDABLE | linux.MS_MOVE
+
+ // Silently allow MS_NOSUID, since we don't implement set-id bits
+ // anyway.
+ const unsupportedFlags = linux.MS_NODEV |
+ linux.MS_NODIRATIME | linux.MS_STRICTATIME
+
+ // Linux just allows passing any flags to mount(2) - it won't fail when
+ // unknown or unsupported flags are passed. Since we don't implement
+ // everything, we fail explicitly on flags that are unimplemented.
+ if flags&(unsupportedOps|unsupportedFlags) != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ var opts vfs.MountOptions
+ if flags&linux.MS_NOATIME == linux.MS_NOATIME {
+ opts.Flags.NoATime = true
+ }
+ if flags&linux.MS_NOEXEC == linux.MS_NOEXEC {
+ opts.Flags.NoExec = true
+ }
+ if flags&linux.MS_RDONLY == linux.MS_RDONLY {
+ opts.ReadOnly = true
+ }
+ opts.GetFilesystemOptions.Data = data
+
+ target, err := getTaskPathOperation(t, linux.AT_FDCWD, targetPath, disallowEmptyPath, nofollowFinalSymlink)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer target.Release()
+
+ return 0, nil, t.Kernel().VFS().MountAt(t, creds, source, &target.pop, fsType, &opts)
+}
+
+// Umount2 implements Linux syscall umount2(2).
+func Umount2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ addr := args[0].Pointer()
+ flags := args[1].Int()
+
+ // Must have CAP_SYS_ADMIN in the mount namespace's associated user
+ // namespace.
+ //
+ // Currently, this is always the init task's user namespace.
+ creds := t.Credentials()
+ if !creds.HasCapabilityIn(linux.CAP_SYS_ADMIN, t.MountNamespaceVFS2().Owner) {
+ return 0, nil, syserror.EPERM
+ }
+
+ const unsupported = linux.MNT_FORCE | linux.MNT_EXPIRE
+ if flags&unsupported != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ path, err := copyInPath(t, addr)
+ if err != nil {
+ return 0, nil, err
+ }
+ tpop, err := getTaskPathOperation(t, linux.AT_FDCWD, path, disallowEmptyPath, nofollowFinalSymlink)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer tpop.Release()
+
+ opts := vfs.UmountOptions{
+ Flags: uint32(flags),
+ }
+
+ return 0, nil, t.Kernel().VFS().UmountAt(t, creds, &tpop.pop, &opts)
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/read_write.go b/pkg/sentry/syscalls/linux/vfs2/read_write.go
index 3a7ef24f5..7f9debd4a 100644
--- a/pkg/sentry/syscalls/linux/vfs2/read_write.go
+++ b/pkg/sentry/syscalls/linux/vfs2/read_write.go
@@ -93,11 +93,17 @@ func Readv(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
func read(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
n, err := file.Read(t, dst, opts)
if err != syserror.ErrWouldBlock {
+ if n > 0 {
+ file.Dentry().InotifyWithParent(linux.IN_ACCESS, 0, vfs.PathEvent)
+ }
return n, err
}
allowBlock, deadline, hasDeadline := blockPolicy(t, file)
if !allowBlock {
+ if n > 0 {
+ file.Dentry().InotifyWithParent(linux.IN_ACCESS, 0, vfs.PathEvent)
+ }
return n, err
}
@@ -128,6 +134,9 @@ func read(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, opt
}
file.EventUnregister(&w)
+ if total > 0 {
+ file.Dentry().InotifyWithParent(linux.IN_ACCESS, 0, vfs.PathEvent)
+ }
return total, err
}
@@ -248,11 +257,17 @@ func Preadv2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca
func pread(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
n, err := file.PRead(t, dst, offset, opts)
if err != syserror.ErrWouldBlock {
+ if n > 0 {
+ file.Dentry().InotifyWithParent(linux.IN_ACCESS, 0, vfs.PathEvent)
+ }
return n, err
}
allowBlock, deadline, hasDeadline := blockPolicy(t, file)
if !allowBlock {
+ if n > 0 {
+ file.Dentry().InotifyWithParent(linux.IN_ACCESS, 0, vfs.PathEvent)
+ }
return n, err
}
@@ -283,6 +298,9 @@ func pread(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, of
}
file.EventUnregister(&w)
+ if total > 0 {
+ file.Dentry().InotifyWithParent(linux.IN_ACCESS, 0, vfs.PathEvent)
+ }
return total, err
}
@@ -345,11 +363,17 @@ func Writev(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
func write(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
n, err := file.Write(t, src, opts)
if err != syserror.ErrWouldBlock {
+ if n > 0 {
+ file.Dentry().InotifyWithParent(linux.IN_MODIFY, 0, vfs.PathEvent)
+ }
return n, err
}
allowBlock, deadline, hasDeadline := blockPolicy(t, file)
if !allowBlock {
+ if n > 0 {
+ file.Dentry().InotifyWithParent(linux.IN_MODIFY, 0, vfs.PathEvent)
+ }
return n, err
}
@@ -380,6 +404,9 @@ func write(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, op
}
file.EventUnregister(&w)
+ if total > 0 {
+ file.Dentry().InotifyWithParent(linux.IN_MODIFY, 0, vfs.PathEvent)
+ }
return total, err
}
@@ -500,11 +527,17 @@ func Pwritev2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
func pwrite(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
n, err := file.PWrite(t, src, offset, opts)
if err != syserror.ErrWouldBlock {
+ if n > 0 {
+ file.Dentry().InotifyWithParent(linux.IN_MODIFY, 0, vfs.PathEvent)
+ }
return n, err
}
allowBlock, deadline, hasDeadline := blockPolicy(t, file)
if !allowBlock {
+ if n > 0 {
+ file.Dentry().InotifyWithParent(linux.IN_ACCESS, 0, vfs.PathEvent)
+ }
return n, err
}
@@ -535,6 +568,9 @@ func pwrite(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, o
}
file.EventUnregister(&w)
+ if total > 0 {
+ file.Dentry().InotifyWithParent(linux.IN_ACCESS, 0, vfs.PathEvent)
+ }
return total, err
}
diff --git a/pkg/sentry/syscalls/linux/vfs2/splice.go b/pkg/sentry/syscalls/linux/vfs2/splice.go
new file mode 100644
index 000000000..945a364a7
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/splice.go
@@ -0,0 +1,291 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/pipe"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/waiter"
+)
+
+// Splice implements Linux syscall splice(2).
+func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ inFD := args[0].Int()
+ inOffsetPtr := args[1].Pointer()
+ outFD := args[2].Int()
+ outOffsetPtr := args[3].Pointer()
+ count := int64(args[4].SizeT())
+ flags := args[5].Int()
+
+ if count == 0 {
+ return 0, nil, nil
+ }
+ if count > int64(kernel.MAX_RW_COUNT) {
+ count = int64(kernel.MAX_RW_COUNT)
+ }
+
+ // Check for invalid flags.
+ if flags&^(linux.SPLICE_F_MOVE|linux.SPLICE_F_NONBLOCK|linux.SPLICE_F_MORE|linux.SPLICE_F_GIFT) != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Get file descriptions.
+ inFile := t.GetFileVFS2(inFD)
+ if inFile == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer inFile.DecRef()
+ outFile := t.GetFileVFS2(outFD)
+ if outFile == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer outFile.DecRef()
+
+ // Check that both files support the required directionality.
+ if !inFile.IsReadable() || !outFile.IsWritable() {
+ return 0, nil, syserror.EBADF
+ }
+
+ // The operation is non-blocking if anything is non-blocking.
+ //
+ // N.B. This is a rather simplistic heuristic that avoids some
+ // poor edge case behavior since the exact semantics here are
+ // underspecified and vary between versions of Linux itself.
+ nonBlock := ((inFile.StatusFlags()|outFile.StatusFlags())&linux.O_NONBLOCK != 0) || (flags&linux.SPLICE_F_NONBLOCK != 0)
+
+ // At least one file description must represent a pipe.
+ inPipeFD, inIsPipe := inFile.Impl().(*pipe.VFSPipeFD)
+ outPipeFD, outIsPipe := outFile.Impl().(*pipe.VFSPipeFD)
+ if !inIsPipe && !outIsPipe {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Copy in offsets.
+ inOffset := int64(-1)
+ if inOffsetPtr != 0 {
+ if inIsPipe {
+ return 0, nil, syserror.ESPIPE
+ }
+ if inFile.Options().DenyPRead {
+ return 0, nil, syserror.EINVAL
+ }
+ if _, err := t.CopyIn(inOffsetPtr, &inOffset); err != nil {
+ return 0, nil, err
+ }
+ if inOffset < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+ }
+ outOffset := int64(-1)
+ if outOffsetPtr != 0 {
+ if outIsPipe {
+ return 0, nil, syserror.ESPIPE
+ }
+ if outFile.Options().DenyPWrite {
+ return 0, nil, syserror.EINVAL
+ }
+ if _, err := t.CopyIn(outOffsetPtr, &outOffset); err != nil {
+ return 0, nil, err
+ }
+ if outOffset < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+ }
+
+ // Move data.
+ var (
+ n int64
+ err error
+ inCh chan struct{}
+ outCh chan struct{}
+ )
+ for {
+ // If both input and output are pipes, delegate to the pipe
+ // implementation. Otherwise, exactly one end is a pipe, which we
+ // ensure is consistently ordered after the non-pipe FD's locks by
+ // passing the pipe FD as usermem.IO to the non-pipe end.
+ switch {
+ case inIsPipe && outIsPipe:
+ n, err = pipe.Splice(t, outPipeFD, inPipeFD, count)
+ case inIsPipe:
+ if outOffset != -1 {
+ n, err = outFile.PWrite(t, inPipeFD.IOSequence(count), outOffset, vfs.WriteOptions{})
+ outOffset += n
+ } else {
+ n, err = outFile.Write(t, inPipeFD.IOSequence(count), vfs.WriteOptions{})
+ }
+ case outIsPipe:
+ if inOffset != -1 {
+ n, err = inFile.PRead(t, outPipeFD.IOSequence(count), inOffset, vfs.ReadOptions{})
+ inOffset += n
+ } else {
+ n, err = inFile.Read(t, outPipeFD.IOSequence(count), vfs.ReadOptions{})
+ }
+ }
+ if n != 0 || err != syserror.ErrWouldBlock || nonBlock {
+ break
+ }
+
+ // Note that the blocking behavior here is a bit different than the
+ // normal pattern. Because we need to have both data to read and data
+ // to write simultaneously, we actually explicitly block on both of
+ // these cases in turn before returning to the splice operation.
+ if inFile.Readiness(eventMaskRead)&eventMaskRead == 0 {
+ if inCh == nil {
+ inCh = make(chan struct{}, 1)
+ inW, _ := waiter.NewChannelEntry(inCh)
+ inFile.EventRegister(&inW, eventMaskRead)
+ defer inFile.EventUnregister(&inW)
+ continue // Need to refresh readiness.
+ }
+ if err = t.Block(inCh); err != nil {
+ break
+ }
+ }
+ if outFile.Readiness(eventMaskWrite)&eventMaskWrite == 0 {
+ if outCh == nil {
+ outCh = make(chan struct{}, 1)
+ outW, _ := waiter.NewChannelEntry(outCh)
+ outFile.EventRegister(&outW, eventMaskWrite)
+ defer outFile.EventUnregister(&outW)
+ continue // Need to refresh readiness.
+ }
+ if err = t.Block(outCh); err != nil {
+ break
+ }
+ }
+ }
+
+ // Copy updated offsets out.
+ if inOffsetPtr != 0 {
+ if _, err := t.CopyOut(inOffsetPtr, &inOffset); err != nil {
+ return 0, nil, err
+ }
+ }
+ if outOffsetPtr != 0 {
+ if _, err := t.CopyOut(outOffsetPtr, &outOffset); err != nil {
+ return 0, nil, err
+ }
+ }
+
+ if n == 0 {
+ return 0, nil, err
+ }
+
+ // On Linux, inotify behavior is not very consistent with splice(2). We try
+ // our best to emulate Linux for very basic calls to splice, where for some
+ // reason, events are generated for output files, but not input files.
+ outFile.Dentry().InotifyWithParent(linux.IN_MODIFY, 0, vfs.PathEvent)
+ return uintptr(n), nil, nil
+}
+
+// Tee implements Linux syscall tee(2).
+func Tee(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ inFD := args[0].Int()
+ outFD := args[1].Int()
+ count := int64(args[2].SizeT())
+ flags := args[3].Int()
+
+ if count == 0 {
+ return 0, nil, nil
+ }
+ if count > int64(kernel.MAX_RW_COUNT) {
+ count = int64(kernel.MAX_RW_COUNT)
+ }
+
+ // Check for invalid flags.
+ if flags&^(linux.SPLICE_F_MOVE|linux.SPLICE_F_NONBLOCK|linux.SPLICE_F_MORE|linux.SPLICE_F_GIFT) != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Get file descriptions.
+ inFile := t.GetFileVFS2(inFD)
+ if inFile == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer inFile.DecRef()
+ outFile := t.GetFileVFS2(outFD)
+ if outFile == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer outFile.DecRef()
+
+ // Check that both files support the required directionality.
+ if !inFile.IsReadable() || !outFile.IsWritable() {
+ return 0, nil, syserror.EBADF
+ }
+
+ // The operation is non-blocking if anything is non-blocking.
+ //
+ // N.B. This is a rather simplistic heuristic that avoids some
+ // poor edge case behavior since the exact semantics here are
+ // underspecified and vary between versions of Linux itself.
+ nonBlock := ((inFile.StatusFlags()|outFile.StatusFlags())&linux.O_NONBLOCK != 0) || (flags&linux.SPLICE_F_NONBLOCK != 0)
+
+ // Both file descriptions must represent pipes.
+ inPipeFD, inIsPipe := inFile.Impl().(*pipe.VFSPipeFD)
+ outPipeFD, outIsPipe := outFile.Impl().(*pipe.VFSPipeFD)
+ if !inIsPipe || !outIsPipe {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Copy data.
+ var (
+ inCh chan struct{}
+ outCh chan struct{}
+ )
+ for {
+ n, err := pipe.Tee(t, outPipeFD, inPipeFD, count)
+ if n != 0 {
+ return uintptr(n), nil, nil
+ }
+ if err != syserror.ErrWouldBlock || nonBlock {
+ return 0, nil, err
+ }
+
+ // Note that the blocking behavior here is a bit different than the
+ // normal pattern. Because we need to have both data to read and data
+ // to write simultaneously, we actually explicitly block on both of
+ // these cases in turn before returning to the tee operation.
+ if inFile.Readiness(eventMaskRead)&eventMaskRead == 0 {
+ if inCh == nil {
+ inCh = make(chan struct{}, 1)
+ inW, _ := waiter.NewChannelEntry(inCh)
+ inFile.EventRegister(&inW, eventMaskRead)
+ defer inFile.EventUnregister(&inW)
+ continue // Need to refresh readiness.
+ }
+ if err := t.Block(inCh); err != nil {
+ return 0, nil, err
+ }
+ }
+ if outFile.Readiness(eventMaskWrite)&eventMaskWrite == 0 {
+ if outCh == nil {
+ outCh = make(chan struct{}, 1)
+ outW, _ := waiter.NewChannelEntry(outCh)
+ outFile.EventRegister(&outW, eventMaskWrite)
+ defer outFile.EventUnregister(&outW)
+ continue // Need to refresh readiness.
+ }
+ if err := t.Block(outCh); err != nil {
+ return 0, nil, err
+ }
+ }
+ }
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/vfs2.go b/pkg/sentry/syscalls/linux/vfs2/vfs2.go
index a332d01bd..954c82f97 100644
--- a/pkg/sentry/syscalls/linux/vfs2/vfs2.go
+++ b/pkg/sentry/syscalls/linux/vfs2/vfs2.go
@@ -62,7 +62,7 @@ func Override() {
s.Table[55] = syscalls.Supported("getsockopt", GetSockOpt)
s.Table[59] = syscalls.Supported("execve", Execve)
s.Table[72] = syscalls.Supported("fcntl", Fcntl)
- delete(s.Table, 73) // flock
+ s.Table[73] = syscalls.Supported("fcntl", Flock)
s.Table[74] = syscalls.Supported("fsync", Fsync)
s.Table[75] = syscalls.Supported("fdatasync", Fdatasync)
s.Table[76] = syscalls.Supported("truncate", Truncate)
@@ -90,8 +90,8 @@ func Override() {
s.Table[138] = syscalls.Supported("fstatfs", Fstatfs)
s.Table[161] = syscalls.Supported("chroot", Chroot)
s.Table[162] = syscalls.Supported("sync", Sync)
- delete(s.Table, 165) // mount
- delete(s.Table, 166) // umount2
+ s.Table[165] = syscalls.Supported("mount", Mount)
+ s.Table[166] = syscalls.Supported("umount2", Umount2)
delete(s.Table, 187) // readahead
s.Table[188] = syscalls.Supported("setxattr", Setxattr)
s.Table[189] = syscalls.Supported("lsetxattr", Lsetxattr)
@@ -116,9 +116,9 @@ func Override() {
s.Table[232] = syscalls.Supported("epoll_wait", EpollWait)
s.Table[233] = syscalls.Supported("epoll_ctl", EpollCtl)
s.Table[235] = syscalls.Supported("utimes", Utimes)
- delete(s.Table, 253) // inotify_init
- delete(s.Table, 254) // inotify_add_watch
- delete(s.Table, 255) // inotify_rm_watch
+ s.Table[253] = syscalls.PartiallySupported("inotify_init", InotifyInit, "inotify events are only available inside the sandbox.", nil)
+ s.Table[254] = syscalls.PartiallySupported("inotify_add_watch", InotifyAddWatch, "inotify events are only available inside the sandbox.", nil)
+ s.Table[255] = syscalls.PartiallySupported("inotify_rm_watch", InotifyRmWatch, "inotify events are only available inside the sandbox.", nil)
s.Table[257] = syscalls.Supported("openat", Openat)
s.Table[258] = syscalls.Supported("mkdirat", Mkdirat)
s.Table[259] = syscalls.Supported("mknodat", Mknodat)
@@ -134,8 +134,8 @@ func Override() {
s.Table[269] = syscalls.Supported("faccessat", Faccessat)
s.Table[270] = syscalls.Supported("pselect", Pselect)
s.Table[271] = syscalls.Supported("ppoll", Ppoll)
- delete(s.Table, 275) // splice
- delete(s.Table, 276) // tee
+ s.Table[275] = syscalls.Supported("splice", Splice)
+ s.Table[276] = syscalls.Supported("tee", Tee)
s.Table[277] = syscalls.Supported("sync_file_range", SyncFileRange)
s.Table[280] = syscalls.Supported("utimensat", Utimensat)
s.Table[281] = syscalls.Supported("epoll_pwait", EpollPwait)
@@ -151,7 +151,7 @@ func Override() {
s.Table[291] = syscalls.Supported("epoll_create1", EpollCreate1)
s.Table[292] = syscalls.Supported("dup3", Dup3)
s.Table[293] = syscalls.Supported("pipe2", Pipe2)
- delete(s.Table, 294) // inotify_init1
+ s.Table[294] = syscalls.PartiallySupported("inotify_init1", InotifyInit1, "inotify events are only available inside the sandbox.", nil)
s.Table[295] = syscalls.Supported("preadv", Preadv)
s.Table[296] = syscalls.Supported("pwritev", Pwritev)
s.Table[299] = syscalls.Supported("recvmmsg", RecvMMsg)
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-07 00:17:49 +0000