diff options
author | gVisor bot <gvisor-bot@google.com> | 2020-06-28 04:36:07 +0000 |
---|---|---|
committer | gVisor bot <gvisor-bot@google.com> | 2020-06-28 04:36:07 +0000 |
commit | 9e9a5f18d48dc0ca991f3950fd5349f12d84eee5 (patch) | |
tree | 343878864329e48c6db95bb88adda5ca6764b760 /pkg | |
parent | 21e2d1fe0c8adad3082f16fb0dc4e44fbffbee25 (diff) | |
parent | e8f1a5c1f652ba7abb8c4bd842d6afdcab03865a (diff) |
Merge release-20200622.1-39-ge8f1a5c1f (automated)
Diffstat (limited to 'pkg')
-rw-r--r-- | pkg/abi/linux/fcntl.go | 2 | ||||
-rw-r--r-- | pkg/abi/linux/linux_abi_autogen_unsafe.go | 4 | ||||
-rw-r--r-- | pkg/sentry/kernel/fasync/fasync.go | 8 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/sys_file.go | 15 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/vfs2/fd.go | 93 | ||||
-rw-r--r-- | pkg/sentry/vfs/file_description.go | 74 |
6 files changed, 181 insertions, 15 deletions
diff --git a/pkg/abi/linux/fcntl.go b/pkg/abi/linux/fcntl.go index 6663a199c..9242e80a5 100644 --- a/pkg/abi/linux/fcntl.go +++ b/pkg/abi/linux/fcntl.go @@ -55,7 +55,7 @@ type Flock struct { _ [4]byte } -// Flags for F_SETOWN_EX and F_GETOWN_EX. +// Owner types for F_SETOWN_EX and F_GETOWN_EX. const ( F_OWNER_TID = 0 F_OWNER_PID = 1 diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go index 80878b079..ac656f14c 100644 --- a/pkg/abi/linux/linux_abi_autogen_unsafe.go +++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go @@ -124,12 +124,12 @@ func (s *Statx) UnmarshalBytes(src []byte) { // Packed implements marshal.Marshallable.Packed. //go:nosplit func (s *Statx) Packed() bool { - return s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() + return s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() } // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. func (s *Statx) MarshalUnsafe(dst []byte) { - if s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() { + if s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() { safecopy.CopyIn(dst, unsafe.Pointer(s)) } else { s.MarshalBytes(dst) diff --git a/pkg/sentry/kernel/fasync/fasync.go b/pkg/sentry/kernel/fasync/fasync.go index d32c3e90a..323f1dfa5 100644 --- a/pkg/sentry/kernel/fasync/fasync.go +++ b/pkg/sentry/kernel/fasync/fasync.go @@ -20,15 +20,21 @@ import ( "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/waiter" ) -// New creates a new FileAsync. +// New creates a new fs.FileAsync. func New() fs.FileAsync { return &FileAsync{} } +// NewVFS2 creates a new vfs.FileAsync. +func NewVFS2() vfs.FileAsync { + return &FileAsync{} +} + // FileAsync sends signals when the registered file is ready for IO. // // +stateify savable diff --git a/pkg/sentry/syscalls/linux/sys_file.go b/pkg/sentry/syscalls/linux/sys_file.go index 35eba20c5..2797c6a72 100644 --- a/pkg/sentry/syscalls/linux/sys_file.go +++ b/pkg/sentry/syscalls/linux/sys_file.go @@ -900,14 +900,20 @@ func fGetOwn(t *kernel.Task, file *fs.File) int32 { // // If who is positive, it represents a PID. If negative, it represents a PGID. // If the PID or PGID is invalid, the owner is silently unset. -func fSetOwn(t *kernel.Task, file *fs.File, who int32) { +func fSetOwn(t *kernel.Task, file *fs.File, who int32) error { a := file.Async(fasync.New).(*fasync.FileAsync) if who < 0 { + // Check for overflow before flipping the sign. + if who-1 > who { + return syserror.EINVAL + } pg := t.PIDNamespace().ProcessGroupWithID(kernel.ProcessGroupID(-who)) a.SetOwnerProcessGroup(t, pg) + } else { + tg := t.PIDNamespace().ThreadGroupWithID(kernel.ThreadID(who)) + a.SetOwnerThreadGroup(t, tg) } - tg := t.PIDNamespace().ThreadGroupWithID(kernel.ThreadID(who)) - a.SetOwnerThreadGroup(t, tg) + return nil } // Fcntl implements linux syscall fcntl(2). @@ -1042,8 +1048,7 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall case linux.F_GETOWN: return uintptr(fGetOwn(t, file)), nil, nil case linux.F_SETOWN: - fSetOwn(t, file, args[2].Int()) - return 0, nil, nil + return 0, nil, fSetOwn(t, file, args[2].Int()) case linux.F_GETOWN_EX: addr := args[2].Pointer() owner := fGetOwnEx(t, file) diff --git a/pkg/sentry/syscalls/linux/vfs2/fd.go b/pkg/sentry/syscalls/linux/vfs2/fd.go index e68b20bed..7e4c6a56e 100644 --- a/pkg/sentry/syscalls/linux/vfs2/fd.go +++ b/pkg/sentry/syscalls/linux/vfs2/fd.go @@ -20,6 +20,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/fs/lock" "gvisor.dev/gvisor/pkg/sentry/fsimpl/tmpfs" "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/fasync" "gvisor.dev/gvisor/pkg/sentry/kernel/pipe" slinux "gvisor.dev/gvisor/pkg/sentry/syscalls/linux" "gvisor.dev/gvisor/pkg/sentry/vfs" @@ -154,6 +155,47 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall return 0, nil, err } return uintptr(n), nil, nil + case linux.F_GETOWN: + a := file.AsyncHandler() + if a == nil { + return 0, nil, nil + } + owner := getAsyncOwner(t, a.(*fasync.FileAsync)) + if owner.Type == linux.F_OWNER_PGRP { + return uintptr(-owner.PID), nil, nil + } + return uintptr(owner.PID), nil, nil + case linux.F_SETOWN: + who := args[2].Int() + ownerType := int32(linux.F_OWNER_PID) + if who < 0 { + // Check for overflow before flipping the sign. + if who-1 > who { + return 0, nil, syserror.EINVAL + } + ownerType = linux.F_OWNER_PGRP + who = -who + } + a := file.SetAsyncHandler(fasync.NewVFS2).(*fasync.FileAsync) + return 0, nil, setAsyncOwner(t, a, ownerType, who) + case linux.F_GETOWN_EX: + a := file.AsyncHandler() + if a == nil { + return 0, nil, nil + } + addr := args[2].Pointer() + owner := getAsyncOwner(t, a.(*fasync.FileAsync)) + _, err := t.CopyOut(addr, &owner) + return 0, nil, err + case linux.F_SETOWN_EX: + addr := args[2].Pointer() + var owner linux.FOwnerEx + n, err := t.CopyIn(addr, &owner) + if err != nil { + return 0, nil, err + } + a := file.SetAsyncHandler(fasync.NewVFS2).(*fasync.FileAsync) + return uintptr(n), nil, setAsyncOwner(t, a, owner.Type, owner.PID) case linux.F_GETPIPE_SZ: pipefile, ok := file.Impl().(*pipe.VFSPipeFD) if !ok { @@ -177,6 +219,57 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall } } +func getAsyncOwner(t *kernel.Task, a *fasync.FileAsync) linux.FOwnerEx { + ot, otg, opg := a.Owner() + switch { + case ot != nil: + return linux.FOwnerEx{ + Type: linux.F_OWNER_TID, + PID: int32(t.PIDNamespace().IDOfTask(ot)), + } + case otg != nil: + return linux.FOwnerEx{ + Type: linux.F_OWNER_PID, + PID: int32(t.PIDNamespace().IDOfThreadGroup(otg)), + } + case opg != nil: + return linux.FOwnerEx{ + Type: linux.F_OWNER_PGRP, + PID: int32(t.PIDNamespace().IDOfProcessGroup(opg)), + } + default: + return linux.FOwnerEx{} + } +} + +func setAsyncOwner(t *kernel.Task, a *fasync.FileAsync, ownerType, pid int32) error { + switch ownerType { + case linux.F_OWNER_TID: + task := t.PIDNamespace().TaskWithID(kernel.ThreadID(pid)) + if task == nil { + return syserror.ESRCH + } + a.SetOwnerTask(t, task) + return nil + case linux.F_OWNER_PID: + tg := t.PIDNamespace().ThreadGroupWithID(kernel.ThreadID(pid)) + if tg == nil { + return syserror.ESRCH + } + a.SetOwnerThreadGroup(t, tg) + return nil + case linux.F_OWNER_PGRP: + pg := t.PIDNamespace().ProcessGroupWithID(kernel.ProcessGroupID(pid)) + if pg == nil { + return syserror.ESRCH + } + a.SetOwnerProcessGroup(t, pg) + return nil + default: + return syserror.EINVAL + } +} + func posixLock(t *kernel.Task, args arch.SyscallArguments, file *vfs.FileDescription, cmd int32) error { // Copy in the lock request. flockAddr := args[2].Pointer() diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go index e0538ea53..cd1db14ac 100644 --- a/pkg/sentry/vfs/file_description.go +++ b/pkg/sentry/vfs/file_description.go @@ -42,11 +42,20 @@ type FileDescription struct { // operations. refs int64 + // flagsMu protects statusFlags and asyncHandler below. + flagsMu sync.Mutex + // statusFlags contains status flags, "initialized by open(2) and possibly - // modified by fcntl()" - fcntl(2). statusFlags is accessed using atomic - // memory operations. + // modified by fcntl()" - fcntl(2). statusFlags can be read using atomic + // memory operations when it does not need to be synchronized with an + // access to asyncHandler. statusFlags uint32 + // asyncHandler handles O_ASYNC signal generation. It is set with the + // F_SETOWN or F_SETOWN_EX fcntls. For asyncHandler to be used, O_ASYNC must + // also be set by fcntl(2). + asyncHandler FileAsync + // epolls is the set of epollInterests registered for this FileDescription. // epolls is protected by epollMu. epollMu sync.Mutex @@ -193,6 +202,13 @@ func (fd *FileDescription) DecRef() { fd.vd.mount.EndWrite() } fd.vd.DecRef() + fd.flagsMu.Lock() + // TODO(gvisor.dev/issue/1663): We may need to unregister during save, as we do in VFS1. + if fd.statusFlags&linux.O_ASYNC != 0 && fd.asyncHandler != nil { + fd.asyncHandler.Unregister(fd) + } + fd.asyncHandler = nil + fd.flagsMu.Unlock() } else if refs < 0 { panic("FileDescription.DecRef() called without holding a reference") } @@ -276,7 +292,18 @@ func (fd *FileDescription) SetStatusFlags(ctx context.Context, creds *auth.Crede } // TODO(jamieliu): FileDescriptionImpl.SetOAsync()? const settableFlags = linux.O_APPEND | linux.O_ASYNC | linux.O_DIRECT | linux.O_NOATIME | linux.O_NONBLOCK - atomic.StoreUint32(&fd.statusFlags, (oldFlags&^settableFlags)|(flags&settableFlags)) + fd.flagsMu.Lock() + if fd.asyncHandler != nil { + // Use fd.statusFlags instead of oldFlags, which may have become outdated, + // to avoid double registering/unregistering. + if fd.statusFlags&linux.O_ASYNC == 0 && flags&linux.O_ASYNC != 0 { + fd.asyncHandler.Register(fd) + } else if fd.statusFlags&linux.O_ASYNC != 0 && flags&linux.O_ASYNC == 0 { + fd.asyncHandler.Unregister(fd) + } + } + fd.statusFlags = (oldFlags &^ settableFlags) | (flags & settableFlags) + fd.flagsMu.Unlock() return nil } @@ -533,17 +560,23 @@ func (fd *FileDescription) StatFS(ctx context.Context) (linux.Statfs, error) { return fd.impl.StatFS(ctx) } -// Readiness returns fd's I/O readiness. +// Readiness implements waiter.Waitable.Readiness. +// +// It returns fd's I/O readiness. func (fd *FileDescription) Readiness(mask waiter.EventMask) waiter.EventMask { return fd.impl.Readiness(mask) } -// EventRegister registers e for I/O readiness events in mask. +// EventRegister implements waiter.Waitable.EventRegister. +// +// It registers e for I/O readiness events in mask. func (fd *FileDescription) EventRegister(e *waiter.Entry, mask waiter.EventMask) { fd.impl.EventRegister(e, mask) } -// EventUnregister unregisters e for I/O readiness events. +// EventUnregister implements waiter.Waitable.EventUnregister. +// +// It unregisters e for I/O readiness events. func (fd *FileDescription) EventUnregister(e *waiter.Entry) { fd.impl.EventUnregister(e) } @@ -770,3 +803,32 @@ func (fd *FileDescription) LockPOSIX(ctx context.Context, uid lock.UniqueID, t l func (fd *FileDescription) UnlockPOSIX(ctx context.Context, uid lock.UniqueID, start, end uint64, whence int16) error { return fd.impl.UnlockPOSIX(ctx, uid, start, end, whence) } + +// A FileAsync sends signals to its owner when w is ready for IO. This is only +// implemented by pkg/sentry/fasync:FileAsync, but we unfortunately need this +// interface to avoid circular dependencies. +type FileAsync interface { + Register(w waiter.Waitable) + Unregister(w waiter.Waitable) +} + +// AsyncHandler returns the FileAsync for fd. +func (fd *FileDescription) AsyncHandler() FileAsync { + fd.flagsMu.Lock() + defer fd.flagsMu.Unlock() + return fd.asyncHandler +} + +// SetAsyncHandler sets fd.asyncHandler if it has not been set before and +// returns it. +func (fd *FileDescription) SetAsyncHandler(newHandler func() FileAsync) FileAsync { + fd.flagsMu.Lock() + defer fd.flagsMu.Unlock() + if fd.asyncHandler == nil { + fd.asyncHandler = newHandler() + if fd.statusFlags&linux.O_ASYNC != 0 { + fd.asyncHandler.Register(fd) + } + } + return fd.asyncHandler +} |