mirror of
https://github.com/hanzoai/visor.git
synced 2026-09-24 17:04:14 +00:00
Etienne PerotandgVisor bot
da6948a692
This will be used to plumb the syscall number through to a counter metric that exports the number of times an unimplemented syscall has been called. Plenty of syscall implementations call `EmitUnimplementedEvent` for flags and settings that are not implemented. With `sysno` available, they will be able to plumb that bit of information through. PiperOrigin-RevId: 518635831
279 lines
7.8 KiB
Go
279 lines
7.8 KiB
Go
// 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 linux
|
|
|
|
import (
|
|
"gvisor.dev/gvisor/pkg/abi/linux"
|
|
"gvisor.dev/gvisor/pkg/bits"
|
|
"gvisor.dev/gvisor/pkg/errors/linuxerr"
|
|
"gvisor.dev/gvisor/pkg/fspath"
|
|
"gvisor.dev/gvisor/pkg/hostarch"
|
|
"gvisor.dev/gvisor/pkg/sentry/arch"
|
|
"gvisor.dev/gvisor/pkg/sentry/kernel"
|
|
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
|
|
"gvisor.dev/gvisor/pkg/sentry/vfs"
|
|
)
|
|
|
|
// Stat implements Linux syscall stat(2).
|
|
func Stat(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
|
|
pathAddr := args[0].Pointer()
|
|
statAddr := args[1].Pointer()
|
|
return 0, nil, fstatat(t, linux.AT_FDCWD, pathAddr, statAddr, 0 /* flags */)
|
|
}
|
|
|
|
// Lstat implements Linux syscall lstat(2).
|
|
func Lstat(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
|
|
pathAddr := args[0].Pointer()
|
|
statAddr := args[1].Pointer()
|
|
return 0, nil, fstatat(t, linux.AT_FDCWD, pathAddr, statAddr, linux.AT_SYMLINK_NOFOLLOW)
|
|
}
|
|
|
|
// Newfstatat implements Linux syscall newfstatat, which backs fstatat(2).
|
|
func Newfstatat(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
|
|
dirfd := args[0].Int()
|
|
pathAddr := args[1].Pointer()
|
|
statAddr := args[2].Pointer()
|
|
flags := args[3].Int()
|
|
return 0, nil, fstatat(t, dirfd, pathAddr, statAddr, flags)
|
|
}
|
|
|
|
func fstatat(t *kernel.Task, dirfd int32, pathAddr, statAddr hostarch.Addr, flags int32) error {
|
|
if flags&^(linux.AT_EMPTY_PATH|linux.AT_SYMLINK_NOFOLLOW) != 0 {
|
|
return linuxerr.EINVAL
|
|
}
|
|
|
|
opts := vfs.StatOptions{
|
|
Mask: linux.STATX_BASIC_STATS,
|
|
}
|
|
|
|
path, err := copyInPath(t, pathAddr)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
root := t.FSContext().RootDirectory()
|
|
defer root.DecRef(t)
|
|
start := root
|
|
if !path.Absolute {
|
|
if !path.HasComponents() && flags&linux.AT_EMPTY_PATH == 0 {
|
|
return linuxerr.ENOENT
|
|
}
|
|
if dirfd == linux.AT_FDCWD {
|
|
start = t.FSContext().WorkingDirectory()
|
|
defer start.DecRef(t)
|
|
} else {
|
|
dirfile := t.GetFile(dirfd)
|
|
if dirfile == nil {
|
|
return linuxerr.EBADF
|
|
}
|
|
if !path.HasComponents() {
|
|
// Use FileDescription.Stat() instead of
|
|
// VirtualFilesystem.StatAt() for fstatat(fd, ""), since the
|
|
// former may be able to use opened file state to expedite the
|
|
// Stat.
|
|
statx, err := dirfile.Stat(t, opts)
|
|
dirfile.DecRef(t)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
var stat linux.Stat
|
|
convertStatxToUserStat(t, &statx, &stat)
|
|
_, err = stat.CopyOut(t, statAddr)
|
|
return err
|
|
}
|
|
start = dirfile.VirtualDentry()
|
|
start.IncRef()
|
|
defer start.DecRef(t)
|
|
dirfile.DecRef(t)
|
|
}
|
|
}
|
|
|
|
statx, err := t.Kernel().VFS().StatAt(t, t.Credentials(), &vfs.PathOperation{
|
|
Root: root,
|
|
Start: start,
|
|
Path: path,
|
|
FollowFinalSymlink: flags&linux.AT_SYMLINK_NOFOLLOW == 0,
|
|
}, &opts)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
var stat linux.Stat
|
|
convertStatxToUserStat(t, &statx, &stat)
|
|
_, err = stat.CopyOut(t, statAddr)
|
|
return err
|
|
}
|
|
|
|
func timespecFromStatxTimestamp(sxts linux.StatxTimestamp) linux.Timespec {
|
|
return linux.Timespec{
|
|
Sec: sxts.Sec,
|
|
Nsec: int64(sxts.Nsec),
|
|
}
|
|
}
|
|
|
|
// Fstat implements Linux syscall fstat(2).
|
|
func Fstat(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
|
|
fd := args[0].Int()
|
|
statAddr := args[1].Pointer()
|
|
|
|
file := t.GetFile(fd)
|
|
if file == nil {
|
|
return 0, nil, linuxerr.EBADF
|
|
}
|
|
defer file.DecRef(t)
|
|
|
|
statx, err := file.Stat(t, vfs.StatOptions{
|
|
Mask: linux.STATX_BASIC_STATS,
|
|
})
|
|
if err != nil {
|
|
return 0, nil, err
|
|
}
|
|
var stat linux.Stat
|
|
convertStatxToUserStat(t, &statx, &stat)
|
|
_, err = stat.CopyOut(t, statAddr)
|
|
return 0, nil, err
|
|
}
|
|
|
|
// Statx implements Linux syscall statx(2).
|
|
func Statx(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
|
|
dirfd := args[0].Int()
|
|
pathAddr := args[1].Pointer()
|
|
flags := args[2].Int()
|
|
mask := args[3].Uint()
|
|
statxAddr := args[4].Pointer()
|
|
|
|
// TODO(b/270247637): gVisor does not yet support automount, so
|
|
// AT_NO_AUTOMOUNT flag is a no-op.
|
|
flags &= ^linux.AT_NO_AUTOMOUNT
|
|
|
|
if flags&^(linux.AT_EMPTY_PATH|linux.AT_SYMLINK_NOFOLLOW|linux.AT_STATX_SYNC_TYPE) != 0 {
|
|
return 0, nil, linuxerr.EINVAL
|
|
}
|
|
// Make sure that only one sync type option is set.
|
|
syncType := uint32(flags & linux.AT_STATX_SYNC_TYPE)
|
|
if syncType != 0 && !bits.IsPowerOfTwo32(syncType) {
|
|
return 0, nil, linuxerr.EINVAL
|
|
}
|
|
if mask&linux.STATX__RESERVED != 0 {
|
|
return 0, nil, linuxerr.EINVAL
|
|
}
|
|
|
|
opts := vfs.StatOptions{
|
|
Mask: mask,
|
|
Sync: uint32(flags & linux.AT_STATX_SYNC_TYPE),
|
|
}
|
|
|
|
path, err := copyInPath(t, pathAddr)
|
|
if err != nil {
|
|
return 0, nil, err
|
|
}
|
|
|
|
root := t.FSContext().RootDirectory()
|
|
defer root.DecRef(t)
|
|
start := root
|
|
if !path.Absolute {
|
|
if !path.HasComponents() && flags&linux.AT_EMPTY_PATH == 0 {
|
|
return 0, nil, linuxerr.ENOENT
|
|
}
|
|
if dirfd == linux.AT_FDCWD {
|
|
start = t.FSContext().WorkingDirectory()
|
|
defer start.DecRef(t)
|
|
} else {
|
|
dirfile := t.GetFile(dirfd)
|
|
if dirfile == nil {
|
|
return 0, nil, linuxerr.EBADF
|
|
}
|
|
if !path.HasComponents() {
|
|
// Use FileDescription.Stat() instead of
|
|
// VirtualFilesystem.StatAt() for statx(fd, ""), since the
|
|
// former may be able to use opened file state to expedite the
|
|
// Stat.
|
|
statx, err := dirfile.Stat(t, opts)
|
|
dirfile.DecRef(t)
|
|
if err != nil {
|
|
return 0, nil, err
|
|
}
|
|
userifyStatx(t, &statx)
|
|
_, err = statx.CopyOut(t, statxAddr)
|
|
return 0, nil, err
|
|
}
|
|
start = dirfile.VirtualDentry()
|
|
start.IncRef()
|
|
defer start.DecRef(t)
|
|
dirfile.DecRef(t)
|
|
}
|
|
}
|
|
|
|
statx, err := t.Kernel().VFS().StatAt(t, t.Credentials(), &vfs.PathOperation{
|
|
Root: root,
|
|
Start: start,
|
|
Path: path,
|
|
FollowFinalSymlink: flags&linux.AT_SYMLINK_NOFOLLOW == 0,
|
|
}, &opts)
|
|
if err != nil {
|
|
return 0, nil, err
|
|
}
|
|
userifyStatx(t, &statx)
|
|
_, err = statx.CopyOut(t, statxAddr)
|
|
return 0, nil, err
|
|
}
|
|
|
|
func userifyStatx(t *kernel.Task, statx *linux.Statx) {
|
|
userns := t.UserNamespace()
|
|
statx.UID = uint32(auth.KUID(statx.UID).In(userns).OrOverflow())
|
|
statx.GID = uint32(auth.KGID(statx.GID).In(userns).OrOverflow())
|
|
}
|
|
|
|
// Statfs implements Linux syscall statfs(2).
|
|
func Statfs(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
|
|
pathAddr := args[0].Pointer()
|
|
bufAddr := args[1].Pointer()
|
|
|
|
path, err := copyInPath(t, pathAddr)
|
|
if err != nil {
|
|
return 0, nil, err
|
|
}
|
|
tpop, err := getTaskPathOperation(t, linux.AT_FDCWD, path, disallowEmptyPath, followFinalSymlink)
|
|
if err != nil {
|
|
return 0, nil, err
|
|
}
|
|
defer tpop.Release(t)
|
|
|
|
statfs, err := t.Kernel().VFS().StatFSAt(t, t.Credentials(), &tpop.pop)
|
|
if err != nil {
|
|
return 0, nil, err
|
|
}
|
|
_, err = statfs.CopyOut(t, bufAddr)
|
|
return 0, nil, err
|
|
}
|
|
|
|
// Fstatfs implements Linux syscall fstatfs(2).
|
|
func Fstatfs(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
|
|
fd := args[0].Int()
|
|
bufAddr := args[1].Pointer()
|
|
|
|
tpop, err := getTaskPathOperation(t, fd, fspath.Path{}, allowEmptyPath, nofollowFinalSymlink)
|
|
if err != nil {
|
|
return 0, nil, err
|
|
}
|
|
defer tpop.Release(t)
|
|
|
|
statfs, err := t.Kernel().VFS().StatFSAt(t, t.Credentials(), &tpop.pop)
|
|
if err != nil {
|
|
return 0, nil, err
|
|
}
|
|
_, err = statfs.CopyOut(t, bufAddr)
|
|
return 0, nil, err
|
|
}
|