From 3810a62b3a2e6bb55c3d030e15ba09665f2f91b3 Mon Sep 17 00:00:00 2001 From: Rahat Mahmood Date: Fri, 21 Aug 2020 16:03:38 -0700 Subject: Clarify seek behaviour for kernfs.GenericDirectoryFD. - Remove comment about GenericDirectoryFD not being compatible with dynamic directories. It is currently being used to implement dynamic directories. - Try to handle SEEK_END better than setting the offset to infinity. SEEK_END is poorly defined for dynamic directories anyways, so at least try make it work correctly for the static entries. Updates #1193. PiperOrigin-RevId: 327890128 --- pkg/sentry/fsimpl/sys/sys.go | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'pkg/sentry/fsimpl/sys') diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go index 0401726b6..393feb802 100644 --- a/pkg/sentry/fsimpl/sys/sys.go +++ b/pkg/sentry/fsimpl/sys/sys.go @@ -131,7 +131,9 @@ func (*dir) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.Set // Open implements kernfs.Inode.Open. func (d *dir) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { - fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &d.locks, &opts) + fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &d.locks, &opts, kernfs.GenericDirectoryFDOptions{ + SeekEnd: kernfs.SeekEndStaticEntries, + }) if err != nil { return nil, err } -- cgit v1.2.3 From 5683a8568adc9c13c1cf9d360dae105dc60b145d Mon Sep 17 00:00:00 2001 From: Dean Deng Date: Tue, 25 Aug 2020 16:26:53 -0700 Subject: Expose basic coverage information to userspace through kcov interface. In Linux, a kernel configuration is set that compiles the kernel with a custom function that is called at the beginning of every basic block, which updates the memory-mapped coverage information. The Go coverage tool does not allow us to inject arbitrary instructions into basic blocks, but it does provide data that we can convert to a kcov-like format and transfer them to userspace through a memory mapping. Note that this is not a strict implementation of kcov, which is especially tricky to do because we do not have the same coverage tools available in Go that that are available for the actual Linux kernel. In Linux, a kernel configuration is set that compiles the kernel with a custom function that is called at the beginning of every basic block to write program counters to the kcov memory mapping. In Go, however, coverage tools only give us a count of basic blocks as they are executed. Every time we return to userspace, we collect the coverage information and write out PCs for each block that was executed, providing userspace with the illusion that the kcov data is always up to date. For convenience, we also generate a unique synthetic PC for each block instead of using actual PCs. Finally, we do not provide thread-specific coverage data (each kcov instance only contains PCs executed by the thread owning it); instead, we will supply data for any file specified by -- instrumentation_filter. Also, fix issue in nogo that was causing pkg/coverage:coverage_nogo compilation to fail. PiperOrigin-RevId: 328426526 --- pkg/abi/linux/ioctl.go | 21 +++ pkg/coverage/BUILD | 14 ++ pkg/coverage/coverage.go | 175 +++++++++++++++++++++ pkg/sentry/fsimpl/sys/BUILD | 5 + pkg/sentry/fsimpl/sys/kcov.go | 116 ++++++++++++++ pkg/sentry/fsimpl/sys/sys.go | 18 ++- pkg/sentry/kernel/BUILD | 3 + pkg/sentry/kernel/kcov.go | 321 +++++++++++++++++++++++++++++++++++++++ pkg/sentry/kernel/kcov_unsafe.go | 28 ++++ pkg/sentry/kernel/kernel.go | 2 +- pkg/sentry/kernel/task.go | 18 +++ pkg/sentry/kernel/task_exit.go | 2 + runsc/config/config.go | 6 +- test/syscalls/BUILD | 4 + test/syscalls/linux/BUILD | 14 ++ test/syscalls/linux/kcov.cc | 70 +++++++++ 16 files changed, 813 insertions(+), 4 deletions(-) create mode 100644 pkg/coverage/BUILD create mode 100644 pkg/coverage/coverage.go create mode 100644 pkg/sentry/fsimpl/sys/kcov.go create mode 100644 pkg/sentry/kernel/kcov.go create mode 100644 pkg/sentry/kernel/kcov_unsafe.go create mode 100644 test/syscalls/linux/kcov.cc (limited to 'pkg/sentry/fsimpl/sys') diff --git a/pkg/abi/linux/ioctl.go b/pkg/abi/linux/ioctl.go index 2c5e56ae5..d6dbedc3e 100644 --- a/pkg/abi/linux/ioctl.go +++ b/pkg/abi/linux/ioctl.go @@ -117,3 +117,24 @@ const ( func IOC(dir, typ, nr, size uint32) uint32 { return uint32(dir)<<_IOC_DIRSHIFT | typ<<_IOC_TYPESHIFT | nr<<_IOC_NRSHIFT | size<<_IOC_SIZESHIFT } + +// Kcov ioctls from kernel/kcov.h. +var ( + KCOV_INIT_TRACE = IOC(_IOC_READ, 'c', 1, 8) + KCOV_ENABLE = IOC(_IOC_NONE, 'c', 100, 0) + KCOV_DISABLE = IOC(_IOC_NONE, 'c', 101, 0) +) + +// Kcov trace types from kernel/kcov.h. +const ( + KCOV_TRACE_PC = 0 + KCOV_TRACE_CMP = 1 +) + +// Kcov state constants from kernel/kcov.h. +const ( + KCOV_MODE_DISABLED = 0 + KCOV_MODE_INIT = 1 + KCOV_MODE_TRACE_PC = 2 + KCOV_MODE_TRACE_CMP = 3 +) diff --git a/pkg/coverage/BUILD b/pkg/coverage/BUILD new file mode 100644 index 000000000..a198e8028 --- /dev/null +++ b/pkg/coverage/BUILD @@ -0,0 +1,14 @@ +load("//tools:defs.bzl", "go_library") + +package(licenses = ["notice"]) + +go_library( + name = "coverage", + srcs = ["coverage.go"], + visibility = ["//:sandbox"], + deps = [ + "//pkg/sync", + "//pkg/usermem", + "@io_bazel_rules_go//go/tools/coverdata", + ], +) diff --git a/pkg/coverage/coverage.go b/pkg/coverage/coverage.go new file mode 100644 index 000000000..6831adcce --- /dev/null +++ b/pkg/coverage/coverage.go @@ -0,0 +1,175 @@ +// 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 coverage provides an interface through which Go coverage data can +// be collected, converted to kcov format, and exposed to userspace. +// +// Coverage can be enabled by calling bazel {build,test} with +// --collect_coverage_data and --instrumentation_filter with the desired +// coverage surface. This causes bazel to use the Go cover tool manually to +// generate instrumented files. It injects a hook that registers all coverage +// data with the coverdata package. +package coverage + +import ( + "fmt" + "io" + "sort" + "sync/atomic" + + "gvisor.dev/gvisor/pkg/sync" + "gvisor.dev/gvisor/pkg/usermem" + + "github.com/bazelbuild/rules_go/go/tools/coverdata" +) + +// KcovAvailable returns whether the kcov coverage interface is available. It is +// available as long as coverage is enabled for some files. +func KcovAvailable() bool { + return len(coverdata.Cover.Blocks) > 0 +} + +// coverageMu must be held while accessing coverdata.Cover. This prevents +// concurrent reads/writes from multiple threads collecting coverage data. +var coverageMu sync.RWMutex + +// once ensures that globalData is only initialized once. +var once sync.Once + +var globalData struct { + // files is the set of covered files sorted by filename. It is calculated at + // startup. + files []string + + // syntheticPCs are a set of PCs calculated at startup, where the PC + // at syntheticPCs[i][j] corresponds to file i, block j. + syntheticPCs [][]uint64 +} + +// ClearCoverageData clears existing coverage data. +func ClearCoverageData() { + coverageMu.Lock() + defer coverageMu.Unlock() + for _, counters := range coverdata.Cover.Counters { + for index := 0; index < len(counters); index++ { + atomic.StoreUint32(&counters[index], 0) + } + } +} + +var coveragePool = sync.Pool{ + New: func() interface{} { + return make([]byte, 0) + }, +} + +// ConsumeCoverageData builds and writes the collection of covered PCs. It +// returns the number of bytes written. +// +// In Linux, a kernel configuration is set that compiles the kernel with a +// custom function that is called at the beginning of every basic block, which +// updates the memory-mapped coverage information. The Go coverage tool does not +// allow us to inject arbitrary instructions into basic blocks, but it does +// provide data that we can convert to a kcov-like format and transfer them to +// userspace through a memory mapping. +// +// Note that this is not a strict implementation of kcov, which is especially +// tricky to do because we do not have the same coverage tools available in Go +// that that are available for the actual Linux kernel. In Linux, a kernel +// configuration is set that compiles the kernel with a custom function that is +// called at the beginning of every basic block to write program counters to the +// kcov memory mapping. In Go, however, coverage tools only give us a count of +// basic blocks as they are executed. Every time we return to userspace, we +// collect the coverage information and write out PCs for each block that was +// executed, providing userspace with the illusion that the kcov data is always +// up to date. For convenience, we also generate a unique synthetic PC for each +// block instead of using actual PCs. Finally, we do not provide thread-specific +// coverage data (each kcov instance only contains PCs executed by the thread +// owning it); instead, we will supply data for any file specified by -- +// instrumentation_filter. +// +// Note that we "consume", i.e. clear, coverdata when this function is run, to +// ensure that each event is only reported once. +// +// TODO(b/160639712): evaluate whether it is ok to reset the global coverage +// data every time this function is run. We could technically have each thread +// store a local snapshot against which we compare the most recent coverdata so +// that separate threads do not affect each other's view of the data. +func ConsumeCoverageData(w io.Writer) int { + once.Do(initCoverageData) + + coverageMu.Lock() + defer coverageMu.Unlock() + + total := 0 + var pcBuffer [8]byte + for fileIndex, file := range globalData.files { + counters := coverdata.Cover.Counters[file] + for index := 0; index < len(counters); index++ { + val := atomic.SwapUint32(&counters[index], 0) + if val != 0 { + // Calculate the synthetic PC. + pc := globalData.syntheticPCs[fileIndex][index] + + usermem.ByteOrder.PutUint64(pcBuffer[:], pc) + n, err := w.Write(pcBuffer[:]) + if err != nil { + if err == io.EOF { + // Simply stop writing if we encounter EOF; it's ok if we attempted to + // write more than we can hold. + return total + n + } + panic(fmt.Sprintf("Internal error writing PCs to kcov area: %v", err)) + } + total += n + } + } + } + + if total == 0 { + // An empty profile indicates that coverage is not enabled, in which case + // there shouldn't be any task work registered. + panic("kcov task work is registered, but no coverage data was found") + } + return total +} + +// initCoverageData initializes globalData. It should only be called once, +// before any kcov data is written. +func initCoverageData() { + // First, order all files. Then calculate synthetic PCs for every block + // (using the well-defined ordering for files as well). + for file := range coverdata.Cover.Blocks { + globalData.files = append(globalData.files, file) + } + sort.Strings(globalData.files) + + // nextSyntheticPC is the first PC that we generate for a block. + // + // This uses a standard-looking kernel range for simplicity. + // + // FIXME(b/160639712): This is only necessary because syzkaller requires + // addresses in the kernel range. If we can remove this constraint, then we + // should be able to use the actual addresses. + var nextSyntheticPC uint64 = 0xffffffff80000000 + for _, file := range globalData.files { + blocks := coverdata.Cover.Blocks[file] + thisFile := make([]uint64, 0, len(blocks)) + for range blocks { + thisFile = append(thisFile, nextSyntheticPC) + nextSyntheticPC++ // Advance. + } + globalData.syntheticPCs = append(globalData.syntheticPCs, thisFile) + } +} diff --git a/pkg/sentry/fsimpl/sys/BUILD b/pkg/sentry/fsimpl/sys/BUILD index 1b548ccd4..f9b232da6 100644 --- a/pkg/sentry/fsimpl/sys/BUILD +++ b/pkg/sentry/fsimpl/sys/BUILD @@ -5,17 +5,22 @@ licenses(["notice"]) go_library( name = "sys", srcs = [ + "kcov.go", "sys.go", ], visibility = ["//pkg/sentry:internal"], deps = [ "//pkg/abi/linux", "//pkg/context", + "//pkg/coverage", + "//pkg/sentry/arch", "//pkg/sentry/fsimpl/kernfs", "//pkg/sentry/kernel", "//pkg/sentry/kernel/auth", + "//pkg/sentry/memmap", "//pkg/sentry/vfs", "//pkg/syserror", + "//pkg/usermem", ], ) diff --git a/pkg/sentry/fsimpl/sys/kcov.go b/pkg/sentry/fsimpl/sys/kcov.go new file mode 100644 index 000000000..92710d877 --- /dev/null +++ b/pkg/sentry/fsimpl/sys/kcov.go @@ -0,0 +1,116 @@ +// 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 sys + +import ( + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/memmap" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/usermem" +) + +func (fs *filesystem) newKcovFile(ctx context.Context, creds *auth.Credentials) *kernfs.Dentry { + k := &kcovInode{} + k.InodeAttrs.Init(creds, 0, 0, fs.NextIno(), linux.S_IFREG|0600) + d := &kernfs.Dentry{} + d.Init(k) + return d +} + +// kcovInode implements kernfs.Inode. +type kcovInode struct { + kernfs.InodeAttrs + kernfs.InodeNoopRefCount + kernfs.InodeNotSymlink + kernfs.InodeNotDirectory +} + +func (i *kcovInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + k := kernel.KernelFromContext(ctx) + if k == nil { + panic("KernelFromContext returned nil") + } + fd := &kcovFD{ + inode: i, + kcov: k.NewKcov(), + } + + if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{ + DenyPRead: true, + DenyPWrite: true, + }); err != nil { + return nil, err + } + return &fd.vfsfd, nil +} + +type kcovFD struct { + vfs.FileDescriptionDefaultImpl + vfs.NoLockFD + + vfsfd vfs.FileDescription + inode *kcovInode + kcov *kernel.Kcov +} + +// Ioctl implements vfs.FileDescriptionImpl.Ioctl. +func (fd *kcovFD) Ioctl(ctx context.Context, uio usermem.IO, args arch.SyscallArguments) (uintptr, error) { + cmd := uint32(args[1].Int()) + arg := args[2].Uint64() + switch uint32(cmd) { + case linux.KCOV_INIT_TRACE: + return 0, fd.kcov.InitTrace(arg) + case linux.KCOV_ENABLE: + return 0, fd.kcov.EnableTrace(ctx, uint8(arg)) + case linux.KCOV_DISABLE: + if arg != 0 { + // This arg is unused; it should be 0. + return 0, syserror.EINVAL + } + return 0, fd.kcov.DisableTrace(ctx) + default: + return 0, syserror.ENOTTY + } +} + +// ConfigureMmap implements vfs.FileDescriptionImpl.ConfigureMmap. +func (fd *kcovFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpts) error { + return fd.kcov.ConfigureMMap(ctx, opts) +} + +// Release implements vfs.FileDescriptionImpl.Release. +func (fd *kcovFD) Release(ctx context.Context) { + // kcov instances have reference counts in Linux, but this seems sufficient + // for our purposes. + fd.kcov.Reset() +} + +// SetStat implements vfs.FileDescriptionImpl.SetStat. +func (fd *kcovFD) SetStat(ctx context.Context, opts vfs.SetStatOptions) error { + creds := auth.CredentialsFromContext(ctx) + fs := fd.vfsfd.VirtualDentry().Mount().Filesystem() + return fd.inode.SetStat(ctx, fs, creds, opts) +} + +// Stat implements vfs.FileDescriptionImpl.Stat. +func (fd *kcovFD) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) { + return fd.inode.Stat(ctx, fd.vfsfd.Mount().Filesystem(), opts) +} diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go index 393feb802..1f042d9f7 100644 --- a/pkg/sentry/fsimpl/sys/sys.go +++ b/pkg/sentry/fsimpl/sys/sys.go @@ -21,6 +21,7 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/coverage" "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" @@ -73,7 +74,7 @@ func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt }), "firmware": fs.newDir(creds, defaultSysDirMode, nil), "fs": fs.newDir(creds, defaultSysDirMode, nil), - "kernel": fs.newDir(creds, defaultSysDirMode, nil), + "kernel": kernelDir(ctx, fs, creds), "module": fs.newDir(creds, defaultSysDirMode, nil), "power": fs.newDir(creds, defaultSysDirMode, nil), }) @@ -94,6 +95,21 @@ func cpuDir(ctx context.Context, fs *filesystem, creds *auth.Credentials) *kernf return fs.newDir(creds, defaultSysDirMode, children) } +func kernelDir(ctx context.Context, fs *filesystem, creds *auth.Credentials) *kernfs.Dentry { + // If kcov is available, set up /sys/kernel/debug/kcov. Technically, debugfs + // should be mounted at debug/, but for our purposes, it is sufficient to + // keep it in sys. + var children map[string]*kernfs.Dentry + if coverage.KcovAvailable() { + children = map[string]*kernfs.Dentry{ + "debug": fs.newDir(creds, linux.FileMode(0700), map[string]*kernfs.Dentry{ + "kcov": fs.newKcovFile(ctx, creds), + }), + } + } + return fs.newDir(creds, defaultSysDirMode, children) +} + // Release implements vfs.FilesystemImpl.Release. func (fs *filesystem) Release(ctx context.Context) { fs.Filesystem.VFSFilesystem().VirtualFilesystem().PutAnonBlockDevMinor(fs.devMinor) diff --git a/pkg/sentry/kernel/BUILD b/pkg/sentry/kernel/BUILD index 5416a310d..d1ecceba3 100644 --- a/pkg/sentry/kernel/BUILD +++ b/pkg/sentry/kernel/BUILD @@ -91,6 +91,8 @@ go_library( "fd_table_unsafe.go", "fs_context.go", "ipc_namespace.go", + "kcov.go", + "kcov_unsafe.go", "kernel.go", "kernel_opts.go", "kernel_state.go", @@ -157,6 +159,7 @@ go_library( "//pkg/bits", "//pkg/bpf", "//pkg/context", + "//pkg/coverage", "//pkg/cpuid", "//pkg/eventchannel", "//pkg/fspath", diff --git a/pkg/sentry/kernel/kcov.go b/pkg/sentry/kernel/kcov.go new file mode 100644 index 000000000..aad63aa99 --- /dev/null +++ b/pkg/sentry/kernel/kcov.go @@ -0,0 +1,321 @@ +// 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 kernel + +import ( + "fmt" + "io" + "sync" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/coverage" + "gvisor.dev/gvisor/pkg/safemem" + "gvisor.dev/gvisor/pkg/sentry/memmap" + "gvisor.dev/gvisor/pkg/sentry/mm" + "gvisor.dev/gvisor/pkg/sentry/pgalloc" + "gvisor.dev/gvisor/pkg/sentry/usage" + "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/usermem" +) + +// kcovAreaSizeMax is the maximum number of uint64 entries allowed in the kcov +// area. On Linux, the maximum is INT_MAX / 8. +const kcovAreaSizeMax = 10 * 1024 * 1024 + +// Kcov provides kernel coverage data to userspace through a memory-mapped +// region, as kcov does in Linux. +// +// To give the illusion that the data is always up to date, we update the shared +// memory every time before we return to userspace. +type Kcov struct { + // mfp provides application memory. It is immutable after creation. + mfp pgalloc.MemoryFileProvider + + // mu protects all of the fields below. + mu sync.RWMutex + + // mode is the current kcov mode. + mode uint8 + + // size is the size of the mapping through which the kernel conveys coverage + // information to userspace. + size uint64 + + // owningTask is the task that currently owns coverage data on the system. The + // interface for kcov essentially requires that coverage is only going to a + // single task. Note that kcov should only generate coverage data for the + // owning task, but we currently generate global coverage. + owningTask *Task + + // count is a locally cached version of the first uint64 in the kcov data, + // which is the number of subsequent entries representing PCs. + // + // It is used with kcovInode.countBlock(), to copy in/out the first element of + // the actual data in an efficient manner, avoid boilerplate, and prevent + // accidental garbage escapes by the temporary counts. + count uint64 + + mappable *mm.SpecialMappable +} + +// NewKcov creates and returns a Kcov instance. +func (k *Kernel) NewKcov() *Kcov { + return &Kcov{ + mfp: k, + } +} + +var coveragePool = sync.Pool{ + New: func() interface{} { + return make([]byte, 0) + }, +} + +// TaskWork implements TaskWorker.TaskWork. +func (kcov *Kcov) TaskWork(t *Task) { + kcov.mu.Lock() + defer kcov.mu.Unlock() + + rw := &kcovReadWriter{ + mf: kcov.mfp.MemoryFile(), + fr: kcov.mappable.FileRange(), + } + + // Read in the PC count. + if _, err := safemem.ReadFullToBlocks(rw, kcov.countBlock()); err != nil { + panic(fmt.Sprintf("Internal error reading count from kcov area: %v", err)) + } + + rw.off = 8 * (1 + kcov.count) + n := coverage.ConsumeCoverageData(&kcovIOWriter{rw}) + + // Update the pc count, based on the number of entries written. Note that if + // we reached the end of the kcov area, we may not have written everything in + // output. + kcov.count += uint64(n / 8) + rw.off = 0 + if _, err := safemem.WriteFullFromBlocks(rw, kcov.countBlock()); err != nil { + panic(fmt.Sprintf("Internal error writing count to kcov area: %v", err)) + } + + // Re-register for future work. + t.RegisterWork(kcov) +} + +// InitTrace performs the KCOV_INIT_TRACE ioctl. +func (kcov *Kcov) InitTrace(size uint64) error { + kcov.mu.Lock() + defer kcov.mu.Unlock() + + if kcov.mode != linux.KCOV_MODE_DISABLED { + return syserror.EBUSY + } + + // To simplify all the logic around mapping, we require that the length of the + // shared region is a multiple of the system page size. + if (8*size)&(usermem.PageSize-1) != 0 { + return syserror.EINVAL + } + + // We need space for at least two uint64s to hold current position and a + // single PC. + if size < 2 || size > kcovAreaSizeMax { + return syserror.EINVAL + } + + kcov.size = size + kcov.mode = linux.KCOV_MODE_INIT + return nil +} + +// EnableTrace performs the KCOV_ENABLE_TRACE ioctl. +func (kcov *Kcov) EnableTrace(ctx context.Context, traceMode uint8) error { + t := TaskFromContext(ctx) + if t == nil { + panic("kcovInode.EnableTrace() cannot be used outside of a task goroutine") + } + + kcov.mu.Lock() + defer kcov.mu.Unlock() + + // KCOV_ENABLE must be preceded by KCOV_INIT_TRACE and an mmap call. + if kcov.mode != linux.KCOV_MODE_INIT || kcov.mappable == nil { + return syserror.EINVAL + } + + switch traceMode { + case linux.KCOV_TRACE_PC: + kcov.mode = traceMode + case linux.KCOV_TRACE_CMP: + // We do not support KCOV_MODE_TRACE_CMP. + return syserror.ENOTSUP + default: + return syserror.EINVAL + } + + if kcov.owningTask != nil && kcov.owningTask != t { + return syserror.EBUSY + } + + kcov.owningTask = t + t.RegisterWork(kcov) + + // Clear existing coverage data; the task expects to read only coverage data + // from the time it is activated. + coverage.ClearCoverageData() + return nil +} + +// DisableTrace performs the KCOV_DISABLE_TRACE ioctl. +func (kcov *Kcov) DisableTrace(ctx context.Context) error { + kcov.mu.Lock() + defer kcov.mu.Unlock() + + t := TaskFromContext(ctx) + if t == nil { + panic("kcovInode.EnableTrace() cannot be used outside of a task goroutine") + } + + if t != kcov.owningTask { + return syserror.EINVAL + } + kcov.owningTask = nil + kcov.mode = linux.KCOV_MODE_INIT + kcov.resetLocked() + return nil +} + +// Reset is called when the owning task exits. +func (kcov *Kcov) Reset() { + kcov.mu.Lock() + kcov.resetLocked() + kcov.mu.Unlock() +} + +// The kcov instance is reset when the owning task exits or when tracing is +// disabled. +func (kcov *Kcov) resetLocked() { + kcov.owningTask = nil + if kcov.mappable != nil { + kcov.mappable = nil + } +} + +// ConfigureMMap is called by the vfs.FileDescription for this kcov instance to +// implement vfs.FileDescription.ConfigureMMap. +func (kcov *Kcov) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpts) error { + kcov.mu.Lock() + defer kcov.mu.Unlock() + + if kcov.mode != linux.KCOV_MODE_INIT { + return syserror.EINVAL + } + + if kcov.mappable == nil { + // Set up the kcov area. + fr, err := kcov.mfp.MemoryFile().Allocate(kcov.size*8, usage.Anonymous) + if err != nil { + return err + } + + // Get the thread id for the mmap name. + t := TaskFromContext(ctx) + if t == nil { + panic("ThreadFromContext returned nil") + } + // For convenience, a special mappable is used here. Note that these mappings + // will look different under /proc/[pid]/maps than they do on Linux. + kcov.mappable = mm.NewSpecialMappable(fmt.Sprintf("[kcov:%d]", t.ThreadID()), kcov.mfp, fr) + } + opts.Mappable = kcov.mappable + opts.MappingIdentity = kcov.mappable + return nil +} + +// kcovReadWriter implements safemem.Reader and safemem.Writer. +type kcovReadWriter struct { + off uint64 + mf *pgalloc.MemoryFile + fr memmap.FileRange +} + +// ReadToBlocks implements safemem.Reader.ReadToBlocks. +func (rw *kcovReadWriter) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) { + if dsts.IsEmpty() { + return 0, nil + } + + // Limit the read to the kcov range and check for overflow. + if rw.fr.Length() <= rw.off { + return 0, io.EOF + } + start := rw.fr.Start + rw.off + end := rw.fr.Start + rw.fr.Length() + if rend := start + dsts.NumBytes(); rend < end { + end = rend + } + + // Get internal mappings. + bs, err := rw.mf.MapInternal(memmap.FileRange{start, end}, usermem.Read) + if err != nil { + return 0, err + } + + // Copy from internal mappings. + n, err := safemem.CopySeq(dsts, bs) + rw.off += n + return n, err +} + +// WriteFromBlocks implements safemem.Writer.WriteFromBlocks. +func (rw *kcovReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error) { + if srcs.IsEmpty() { + return 0, nil + } + + // Limit the write to the kcov area and check for overflow. + if rw.fr.Length() <= rw.off { + return 0, io.EOF + } + start := rw.fr.Start + rw.off + end := rw.fr.Start + rw.fr.Length() + if wend := start + srcs.NumBytes(); wend < end { + end = wend + } + + // Get internal mapping. + bs, err := rw.mf.MapInternal(memmap.FileRange{start, end}, usermem.Write) + if err != nil { + return 0, err + } + + // Copy to internal mapping. + n, err := safemem.CopySeq(bs, srcs) + rw.off += n + return n, err +} + +// kcovIOWriter implements io.Writer as a basic wrapper over kcovReadWriter. +type kcovIOWriter struct { + rw *kcovReadWriter +} + +// Write implements io.Writer.Write. +func (w *kcovIOWriter) Write(p []byte) (int, error) { + bs := safemem.BlockSeqOf(safemem.BlockFromSafeSlice(p)) + n, err := safemem.WriteFullFromBlocks(w.rw, bs) + return int(n), err +} diff --git a/pkg/sentry/kernel/kcov_unsafe.go b/pkg/sentry/kernel/kcov_unsafe.go new file mode 100644 index 000000000..6f64022eb --- /dev/null +++ b/pkg/sentry/kernel/kcov_unsafe.go @@ -0,0 +1,28 @@ +// 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 kernel + +import ( + "unsafe" + + "gvisor.dev/gvisor/pkg/safemem" +) + +// countBlock provides a safemem.BlockSeq for k.count. +// +// Like k.count, the block returned is protected by k.mu. +func (k *Kcov) countBlock() safemem.BlockSeq { + return safemem.BlockSeqOf(safemem.BlockFromSafePointer(unsafe.Pointer(&k.count), int(unsafe.Sizeof(k.count)))) +} diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go index 2e0175e36..402aa1718 100644 --- a/pkg/sentry/kernel/kernel.go +++ b/pkg/sentry/kernel/kernel.go @@ -248,7 +248,7 @@ type Kernel struct { // SpecialOpts contains special kernel options. SpecialOpts - // VFS keeps the filesystem state used across the kernel. + // vfs keeps the filesystem state used across the kernel. vfs vfs.VirtualFilesystem // hostMount is the Mount used for file descriptors that were imported diff --git a/pkg/sentry/kernel/task.go b/pkg/sentry/kernel/task.go index 5aee699e7..a436610c9 100644 --- a/pkg/sentry/kernel/task.go +++ b/pkg/sentry/kernel/task.go @@ -574,6 +574,11 @@ type Task struct { // // startTime is protected by mu. startTime ktime.Time + + // kcov is the kcov instance providing code coverage owned by this task. + // + // kcov is exclusive to the task goroutine. + kcov *Kcov } func (t *Task) savePtraceTracer() *Task { @@ -903,3 +908,16 @@ func (t *Task) UID() uint32 { func (t *Task) GID() uint32 { return uint32(t.Credentials().EffectiveKGID) } + +// SetKcov sets the kcov instance associated with t. +func (t *Task) SetKcov(k *Kcov) { + t.kcov = k +} + +// ResetKcov clears the kcov instance associated with t. +func (t *Task) ResetKcov() { + if t.kcov != nil { + t.kcov.Reset() + t.kcov = nil + } +} diff --git a/pkg/sentry/kernel/task_exit.go b/pkg/sentry/kernel/task_exit.go index c165d6cb1..b76f7f503 100644 --- a/pkg/sentry/kernel/task_exit.go +++ b/pkg/sentry/kernel/task_exit.go @@ -239,6 +239,8 @@ func (*runExitMain) execute(t *Task) taskRunState { t.traceExitEvent() lastExiter := t.exitThreadGroup() + t.ResetKcov() + // If the task has a cleartid, and the thread group wasn't killed by a // signal, handle that before releasing the MM. if t.cleartid != 0 { diff --git a/runsc/config/config.go b/runsc/config/config.go index ca85cef51..8cf0378d5 100644 --- a/runsc/config/config.go +++ b/runsc/config/config.go @@ -300,10 +300,10 @@ type Config struct { // E.g. 0.2 CPU quota will result in 1, and 1.9 in 2. CPUNumFromQuota bool - // Enables VFS2 (not plumbled through yet). + // Enables VFS2 (not plumbed through yet). VFS2 bool - // Enables FUSE usage (not plumbled through yet). + // Enables FUSE usage (not plumbed through yet). FUSE bool // TestOnlyAllowRunAsCurrentUserWithoutChroot should only be used in @@ -353,6 +353,8 @@ func (c *Config) ToFlags() []string { "--tx-checksum-offload=" + strconv.FormatBool(c.TXChecksumOffload), "--overlayfs-stale-read=" + strconv.FormatBool(c.OverlayfsStaleRead), "--qdisc=" + c.QDisc.String(), + "--vfs2=" + strconv.FormatBool(c.VFS2), + "--fuse=" + strconv.FormatBool(c.FUSE), } if c.CPUNumFromQuota { f = append(f, "--cpu-num-from-quota") diff --git a/test/syscalls/BUILD b/test/syscalls/BUILD index eea1401ac..65e8299c3 100644 --- a/test/syscalls/BUILD +++ b/test/syscalls/BUILD @@ -262,6 +262,10 @@ syscall_test( test = "//test/syscalls/linux:itimer_test", ) +syscall_test( + test = "//test/syscalls/linux:kcov_test", +) + syscall_test( test = "//test/syscalls/linux:kill_test", ) diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index ed0b6ecf4..5a323d331 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -1067,6 +1067,20 @@ cc_binary( ], ) +cc_binary( + name = "kcov_test", + testonly = 1, + srcs = ["kcov.cc"], + linkstatic = 1, + deps = [ + "//test/util:capability_util", + "//test/util:file_descriptor", + gtest, + "//test/util:test_main", + "//test/util:test_util", + ], +) + cc_binary( name = "kill_test", testonly = 1, diff --git a/test/syscalls/linux/kcov.cc b/test/syscalls/linux/kcov.cc new file mode 100644 index 000000000..f3c30444e --- /dev/null +++ b/test/syscalls/linux/kcov.cc @@ -0,0 +1,70 @@ +// Copyright 2018 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. + +#include +#include +#include + +#include "gtest/gtest.h" +#include "test/util/capability_util.h" +#include "test/util/file_descriptor.h" +#include "test/util/test_util.h" + +namespace gvisor { +namespace testing { + +namespace { + +// For this test to work properly, it must be run with coverage enabled. On +// native Linux, this involves compiling the kernel with kcov enabled. For +// gVisor, we need to enable the Go coverage tool, e.g. +// bazel test --collect_coverage_data --instrumentation_filter=//pkg/... . +TEST(KcovTest, Kcov) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability((CAP_DAC_OVERRIDE)))); + + constexpr int kSize = 4096; + constexpr int KCOV_INIT_TRACE = 0x80086301; + constexpr int KCOV_ENABLE = 0x6364; + + int fd; + ASSERT_THAT(fd = open("/sys/kernel/debug/kcov", O_RDWR), + AnyOf(SyscallSucceeds(), SyscallFailsWithErrno(ENOENT))); + + // Kcov not enabled. + SKIP_IF(errno == ENOENT); + + ASSERT_THAT(ioctl(fd, KCOV_INIT_TRACE, kSize), SyscallSucceeds()); + uint64_t* area = (uint64_t*)mmap(nullptr, kSize * sizeof(uint64_t), + PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + + ASSERT_TRUE(area != MAP_FAILED); + ASSERT_THAT(ioctl(fd, KCOV_ENABLE, 0), SyscallSucceeds()); + + for (int i = 0; i < 10; i++) { + // Make some syscalls to generate coverage data. + ASSERT_THAT(ioctl(fd, KCOV_ENABLE, 0), SyscallFailsWithErrno(EINVAL)); + } + + uint64_t num_pcs = *(uint64_t*)(area); + EXPECT_GT(num_pcs, 0); + for (uint64_t i = 1; i <= num_pcs; i++) { + // Verify that PCs are in the standard kernel range. + EXPECT_GT(area[i], 0xffffffff7fffffffL); + } +} + +} // namespace + +} // namespace testing +} // namespace gvisor -- cgit v1.2.3 From 87e03869065f0784bf9ed76855205693128f65a4 Mon Sep 17 00:00:00 2001 From: Dean Deng Date: Tue, 25 Aug 2020 21:01:45 -0700 Subject: Use new reference count utility throughout gvisor. This uses the refs_vfs2 template in vfs2 as well as objects common to vfs1 and vfs2. Note that vfs1-only refcounts are not replaced, since vfs1 will be deleted soon anyway. The following structs now use the new tool, with leak check enabled: devpts:rootInode fuse:inode kernfs:Dentry kernfs:dir kernfs:readonlyDir kernfs:StaticDirectory proc:fdDirInode proc:fdInfoDirInode proc:subtasksInode proc:taskInode proc:tasksInode vfs:FileDescription vfs:MountNamespace vfs:Filesystem sys:dir kernel:FSContext kernel:ProcessGroup kernel:Session shm:Shm mm:aioMappable mm:SpecialMappable transport:queue And the following use the template, but because they currently are not leak checked, a TODO is left instead of enabling leak check in this patch: kernel:FDTable tun:tunEndpoint Updates #1486. PiperOrigin-RevId: 328460377 --- pkg/refs_vfs2/BUILD | 2 +- pkg/refs_vfs2/refs_template.go | 17 ++++- pkg/sentry/fsimpl/devpts/BUILD | 15 ++++ pkg/sentry/fsimpl/devpts/devpts.go | 7 ++ pkg/sentry/fsimpl/fuse/BUILD | 13 ++++ pkg/sentry/fsimpl/fuse/fusefs.go | 7 ++ pkg/sentry/fsimpl/kernfs/BUILD | 54 ++++++++++++- pkg/sentry/fsimpl/kernfs/inode_impl_util.go | 27 ++++--- pkg/sentry/fsimpl/kernfs/kernfs.go | 24 +++--- pkg/sentry/fsimpl/kernfs/kernfs_test.go | 12 +++ pkg/sentry/fsimpl/proc/BUILD | 61 +++++++++++++++ pkg/sentry/fsimpl/proc/subtasks.go | 7 ++ pkg/sentry/fsimpl/proc/task.go | 8 ++ pkg/sentry/fsimpl/proc/task_fds.go | 16 +++- pkg/sentry/fsimpl/proc/task_net.go | 6 +- pkg/sentry/fsimpl/proc/tasks.go | 7 ++ pkg/sentry/fsimpl/sys/BUILD | 15 ++++ pkg/sentry/fsimpl/sys/sys.go | 9 ++- pkg/sentry/kernel/BUILD | 48 ++++++++++++ pkg/sentry/kernel/fd_table.go | 21 +++-- pkg/sentry/kernel/fd_table_unsafe.go | 2 + pkg/sentry/kernel/fs_context.go | 89 ++++++++++++---------- pkg/sentry/kernel/sessions.go | 29 +++---- pkg/sentry/kernel/shm/BUILD | 13 ++++ pkg/sentry/kernel/shm/shm.go | 19 ++--- pkg/sentry/mm/BUILD | 24 ++++++ pkg/sentry/mm/aio_context.go | 7 +- pkg/sentry/mm/special_mappable.go | 7 +- pkg/sentry/socket/unix/transport/BUILD | 12 +++ pkg/sentry/socket/unix/transport/connectioned.go | 8 +- pkg/sentry/socket/unix/transport/connectionless.go | 2 +- pkg/sentry/socket/unix/transport/queue.go | 13 ++-- pkg/sentry/vfs/BUILD | 37 +++++++++ pkg/sentry/vfs/README.md | 9 --- pkg/sentry/vfs/file_description.go | 39 +--------- pkg/sentry/vfs/filesystem.go | 37 +-------- pkg/sentry/vfs/mount.go | 21 ++--- pkg/tcpip/link/tun/BUILD | 14 ++++ pkg/tcpip/link/tun/device.go | 9 +-- 39 files changed, 531 insertions(+), 236 deletions(-) (limited to 'pkg/sentry/fsimpl/sys') diff --git a/pkg/refs_vfs2/BUILD b/pkg/refs_vfs2/BUILD index 7b3e10683..577b827a5 100644 --- a/pkg/refs_vfs2/BUILD +++ b/pkg/refs_vfs2/BUILD @@ -11,7 +11,7 @@ go_template( types = [ "T", ], - visibility = ["//pkg/sentry:internal"], + visibility = ["//:sandbox"], deps = [ "//pkg/log", "//pkg/refs", diff --git a/pkg/refs_vfs2/refs_template.go b/pkg/refs_vfs2/refs_template.go index 99c43c065..d9b552896 100644 --- a/pkg/refs_vfs2/refs_template.go +++ b/pkg/refs_vfs2/refs_template.go @@ -12,11 +12,15 @@ // See the License for the specific language governing permissions and // limitations under the License. -// Package refs_template defines a template that can be used by reference counted -// objects. +// Package refs_template defines a template that can be used by reference +// counted objects. The "owner" template parameter is used in log messages to +// indicate the type of reference-counted object that exhibited a reference +// leak. As a result, structs that are embedded in other structs should not use +// this template, since it will make tracking down leaks more difficult. package refs_template import ( + "fmt" "runtime" "sync/atomic" @@ -38,6 +42,11 @@ var ownerType *T // Note that the number of references is actually refCount + 1 so that a default // zero-value Refs object contains one reference. // +// TODO(gvisor.dev/issue/1486): Store stack traces when leak check is enabled in +// a map with 16-bit hashes, and store the hash in the top 16 bits of refCount. +// This will allow us to add stack trace information to the leak messages +// without growing the size of Refs. +// // +stateify savable type Refs struct { // refCount is composed of two fields: @@ -82,7 +91,7 @@ func (r *Refs) ReadRefs() int64 { //go:nosplit func (r *Refs) IncRef() { if v := atomic.AddInt64(&r.refCount, 1); v <= 0 { - panic("Incrementing non-positive ref count") + panic(fmt.Sprintf("Incrementing non-positive ref count %p owned by %T", r, ownerType)) } } @@ -122,7 +131,7 @@ func (r *Refs) TryIncRef() bool { func (r *Refs) DecRef(destroy func()) { switch v := atomic.AddInt64(&r.refCount, -1); { case v < -1: - panic("Decrementing non-positive ref count") + panic(fmt.Sprintf("Decrementing non-positive ref count %p, owned by %T", r, ownerType)) case v == -1: // Call the destructor. diff --git a/pkg/sentry/fsimpl/devpts/BUILD b/pkg/sentry/fsimpl/devpts/BUILD index 93512c9b6..3f64fab3a 100644 --- a/pkg/sentry/fsimpl/devpts/BUILD +++ b/pkg/sentry/fsimpl/devpts/BUILD @@ -1,7 +1,19 @@ load("//tools:defs.bzl", "go_library", "go_test") +load("//tools/go_generics:defs.bzl", "go_template_instance") licenses(["notice"]) +go_template_instance( + name = "root_inode_refs", + out = "root_inode_refs.go", + package = "devpts", + prefix = "rootInode", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "rootInode", + }, +) + go_library( name = "devpts", srcs = [ @@ -9,6 +21,7 @@ go_library( "line_discipline.go", "master.go", "queue.go", + "root_inode_refs.go", "slave.go", "terminal.go", ], @@ -16,6 +29,8 @@ go_library( deps = [ "//pkg/abi/linux", "//pkg/context", + "//pkg/log", + "//pkg/refs", "//pkg/safemem", "//pkg/sentry/arch", "//pkg/sentry/fs/lock", diff --git a/pkg/sentry/fsimpl/devpts/devpts.go b/pkg/sentry/fsimpl/devpts/devpts.go index 3f3a099bd..0eaff9087 100644 --- a/pkg/sentry/fsimpl/devpts/devpts.go +++ b/pkg/sentry/fsimpl/devpts/devpts.go @@ -83,6 +83,7 @@ func (fstype FilesystemType) newFilesystem(vfsObj *vfs.VirtualFilesystem, creds } root.InodeAttrs.Init(creds, linux.UNNAMED_MAJOR, devMinor, 1, linux.ModeDirectory|0555) root.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) + root.EnableLeakCheck() root.dentry.Init(root) // Construct the pts master inode and dentry. Linux always uses inode @@ -110,6 +111,7 @@ func (fs *filesystem) Release(ctx context.Context) { // rootInode is the root directory inode for the devpts mounts. type rootInode struct { + rootInodeRefs kernfs.AlwaysValid kernfs.InodeAttrs kernfs.InodeDirectoryNoNewChildren @@ -233,3 +235,8 @@ func (i *rootInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, } return offset, nil } + +// DecRef implements kernfs.Inode. +func (i *rootInode) DecRef(context.Context) { + i.rootInodeRefs.DecRef(i.Destroy) +} diff --git a/pkg/sentry/fsimpl/fuse/BUILD b/pkg/sentry/fsimpl/fuse/BUILD index 999111deb..53a4f3012 100644 --- a/pkg/sentry/fsimpl/fuse/BUILD +++ b/pkg/sentry/fsimpl/fuse/BUILD @@ -15,6 +15,17 @@ go_template_instance( }, ) +go_template_instance( + name = "inode_refs", + out = "inode_refs.go", + package = "fuse", + prefix = "inode", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "inode", + }, +) + go_library( name = "fuse", srcs = [ @@ -22,6 +33,7 @@ go_library( "dev.go", "fusefs.go", "init.go", + "inode_refs.go", "register.go", "request_list.go", ], @@ -30,6 +42,7 @@ go_library( "//pkg/abi/linux", "//pkg/context", "//pkg/log", + "//pkg/refs", "//pkg/sentry/fsimpl/devtmpfs", "//pkg/sentry/fsimpl/kernfs", "//pkg/sentry/kernel", diff --git a/pkg/sentry/fsimpl/fuse/fusefs.go b/pkg/sentry/fsimpl/fuse/fusefs.go index 44021ee4b..9717c0e15 100644 --- a/pkg/sentry/fsimpl/fuse/fusefs.go +++ b/pkg/sentry/fsimpl/fuse/fusefs.go @@ -198,6 +198,7 @@ func (fs *filesystem) Release(ctx context.Context) { // inode implements kernfs.Inode. type inode struct { + inodeRefs kernfs.InodeAttrs kernfs.InodeNoDynamicLookup kernfs.InodeNotSymlink @@ -213,6 +214,7 @@ func (fs *filesystem) newInode(creds *auth.Credentials, mode linux.FileMode) *ke i := &inode{} i.InodeAttrs.Init(creds, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0755) i.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) + i.EnableLeakCheck() i.dentry.Init(i) return &i.dentry @@ -324,3 +326,8 @@ func (i *inode) Stat(ctx context.Context, fs *vfs.Filesystem, opts vfs.StatOptio return statFromFUSEAttr(out.Attr, opts.Mask, fusefs.devMinor), nil } + +// DecRef implements kernfs.Inode. +func (i *inode) DecRef(context.Context) { + i.inodeRefs.DecRef(i.Destroy) +} diff --git a/pkg/sentry/fsimpl/kernfs/BUILD b/pkg/sentry/fsimpl/kernfs/BUILD index 3835557fe..637dca70c 100644 --- a/pkg/sentry/fsimpl/kernfs/BUILD +++ b/pkg/sentry/fsimpl/kernfs/BUILD @@ -26,9 +26,54 @@ go_template_instance( }, ) +go_template_instance( + name = "dentry_refs", + out = "dentry_refs.go", + package = "kernfs", + prefix = "Dentry", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "Dentry", + }, +) + +go_template_instance( + name = "static_directory_refs", + out = "static_directory_refs.go", + package = "kernfs", + prefix = "StaticDirectory", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "StaticDirectory", + }, +) + +go_template_instance( + name = "dir_refs", + out = "dir_refs.go", + package = "kernfs_test", + prefix = "dir", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "dir", + }, +) + +go_template_instance( + name = "readonly_dir_refs", + out = "readonly_dir_refs.go", + package = "kernfs_test", + prefix = "readonlyDir", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "readonlyDir", + }, +) + go_library( name = "kernfs", srcs = [ + "dentry_refs.go", "dynamic_bytes_file.go", "fd_impl_util.go", "filesystem.go", @@ -36,6 +81,7 @@ go_library( "inode_impl_util.go", "kernfs.go", "slot_list.go", + "static_directory_refs.go", "symlink.go", ], visibility = ["//pkg/sentry:internal"], @@ -59,11 +105,17 @@ go_library( go_test( name = "kernfs_test", size = "small", - srcs = ["kernfs_test.go"], + srcs = [ + "dir_refs.go", + "kernfs_test.go", + "readonly_dir_refs.go", + ], deps = [ ":kernfs", "//pkg/abi/linux", "//pkg/context", + "//pkg/log", + "//pkg/refs", "//pkg/sentry/contexttest", "//pkg/sentry/fsimpl/testutil", "//pkg/sentry/kernel/auth", diff --git a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go index 885856868..f442a5606 100644 --- a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go +++ b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go @@ -20,7 +20,6 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sync" @@ -344,8 +343,6 @@ type OrderedChildrenOptions struct { // // Must be initialize with Init before first use. type OrderedChildren struct { - refs.AtomicRefCount - // Can children be modified by user syscalls? It set to false, interface // methods that would modify the children return EPERM. Immutable. writable bool @@ -361,14 +358,14 @@ func (o *OrderedChildren) Init(opts OrderedChildrenOptions) { o.set = make(map[string]*slot) } -// DecRef implements Inode.DecRef. -func (o *OrderedChildren) DecRef(ctx context.Context) { - o.AtomicRefCount.DecRefWithDestructor(ctx, func(context.Context) { - o.mu.Lock() - defer o.mu.Unlock() - o.order.Reset() - o.set = nil - }) +// Destroy clears the children stored in o. It should be called by structs +// embedding OrderedChildren upon destruction, i.e. when their reference count +// reaches zero. +func (o *OrderedChildren) Destroy() { + o.mu.Lock() + defer o.mu.Unlock() + o.order.Reset() + o.set = nil } // Populate inserts children into this OrderedChildren, and d's dentry @@ -549,6 +546,7 @@ func (InodeSymlink) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.D // // +stateify savable type StaticDirectory struct { + StaticDirectoryRefs InodeNotSymlink InodeDirectoryNoNewChildren InodeAttrs @@ -594,11 +592,16 @@ func (s *StaticDirectory) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd return fd.VFSFileDescription(), nil } -// SetStat implements Inode.SetStat not allowing inode attributes to be changed. +// SetStat implements kernfs.Inode.SetStat not allowing inode attributes to be changed. func (*StaticDirectory) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.SetStatOptions) error { return syserror.EPERM } +// DecRef implements kernfs.Inode. +func (s *StaticDirectory) DecRef(context.Context) { + s.StaticDirectoryRefs.DecRef(s.Destroy) +} + // AlwaysValid partially implements kernfs.inodeDynamicLookup. type AlwaysValid struct{} diff --git a/pkg/sentry/fsimpl/kernfs/kernfs.go b/pkg/sentry/fsimpl/kernfs/kernfs.go index 51dbc050c..ca3685800 100644 --- a/pkg/sentry/fsimpl/kernfs/kernfs.go +++ b/pkg/sentry/fsimpl/kernfs/kernfs.go @@ -57,7 +57,6 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sync" @@ -161,9 +160,9 @@ const ( // // Must be initialized by Init prior to first use. type Dentry struct { - vfsd vfs.Dentry + DentryRefs - refs.AtomicRefCount + vfsd vfs.Dentry // flags caches useful information about the dentry from the inode. See the // dflags* consts above. Must be accessed by atomic ops. @@ -194,6 +193,7 @@ func (d *Dentry) Init(inode Inode) { if ftype == linux.ModeSymlink { d.flags |= dflagsIsSymlink } + d.EnableLeakCheck() } // VFSDentry returns the generic vfs dentry for this kernfs dentry. @@ -213,16 +213,14 @@ func (d *Dentry) isSymlink() bool { // DecRef implements vfs.DentryImpl.DecRef. func (d *Dentry) DecRef(ctx context.Context) { - d.AtomicRefCount.DecRefWithDestructor(ctx, d.destroy) -} - -// Precondition: Dentry must be removed from VFS' dentry cache. -func (d *Dentry) destroy(ctx context.Context) { - d.inode.DecRef(ctx) // IncRef from Init. - d.inode = nil - if d.parent != nil { - d.parent.DecRef(ctx) // IncRef from Dentry.InsertChild. - } + // Before the destructor is called, Dentry must be removed from VFS' dentry cache. + d.DentryRefs.DecRef(func() { + d.inode.DecRef(ctx) // IncRef from Init. + d.inode = nil + if d.parent != nil { + d.parent.DecRef(ctx) // IncRef from Dentry.InsertChild. + } + }) } // InotifyWithParent implements vfs.DentryImpl.InotifyWithParent. diff --git a/pkg/sentry/fsimpl/kernfs/kernfs_test.go b/pkg/sentry/fsimpl/kernfs/kernfs_test.go index e5c28c0e4..e376d1736 100644 --- a/pkg/sentry/fsimpl/kernfs/kernfs_test.go +++ b/pkg/sentry/fsimpl/kernfs/kernfs_test.go @@ -96,6 +96,7 @@ func (*attrs) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.S } type readonlyDir struct { + readonlyDirRefs attrs kernfs.InodeNotSymlink kernfs.InodeNoDynamicLookup @@ -111,6 +112,7 @@ func (fs *filesystem) newReadonlyDir(creds *auth.Credentials, mode linux.FileMod dir := &readonlyDir{} dir.attrs.Init(creds, 0 /* devMajor */, 0 /* devMinor */, fs.NextIno(), linux.ModeDirectory|mode) dir.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) + dir.EnableLeakCheck() dir.dentry.Init(dir) dir.IncLinks(dir.OrderedChildren.Populate(&dir.dentry, contents)) @@ -128,7 +130,12 @@ func (d *readonlyDir) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs return fd.VFSFileDescription(), nil } +func (d *readonlyDir) DecRef(context.Context) { + d.readonlyDirRefs.DecRef(d.Destroy) +} + type dir struct { + dirRefs attrs kernfs.InodeNotSymlink kernfs.InodeNoDynamicLookup @@ -145,6 +152,7 @@ func (fs *filesystem) newDir(creds *auth.Credentials, mode linux.FileMode, conte dir.fs = fs dir.attrs.Init(creds, 0 /* devMajor */, 0 /* devMinor */, fs.NextIno(), linux.ModeDirectory|mode) dir.OrderedChildren.Init(kernfs.OrderedChildrenOptions{Writable: true}) + dir.EnableLeakCheck() dir.dentry.Init(dir) dir.IncLinks(dir.OrderedChildren.Populate(&dir.dentry, contents)) @@ -162,6 +170,10 @@ func (d *dir) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, return fd.VFSFileDescription(), nil } +func (d *dir) DecRef(context.Context) { + d.dirRefs.DecRef(d.Destroy) +} + func (d *dir) NewDir(ctx context.Context, name string, opts vfs.MkdirOptions) (*vfs.Dentry, error) { creds := auth.CredentialsFromContext(ctx) dir := d.fs.newDir(creds, opts.Mode, nil) diff --git a/pkg/sentry/fsimpl/proc/BUILD b/pkg/sentry/fsimpl/proc/BUILD index 14ecfd300..a45b44440 100644 --- a/pkg/sentry/fsimpl/proc/BUILD +++ b/pkg/sentry/fsimpl/proc/BUILD @@ -1,18 +1,79 @@ load("//tools:defs.bzl", "go_library", "go_test") +load("//tools/go_generics:defs.bzl", "go_template_instance") licenses(["notice"]) +go_template_instance( + name = "fd_dir_inode_refs", + out = "fd_dir_inode_refs.go", + package = "proc", + prefix = "fdDirInode", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "fdDirInode", + }, +) + +go_template_instance( + name = "fd_info_dir_inode_refs", + out = "fd_info_dir_inode_refs.go", + package = "proc", + prefix = "fdInfoDirInode", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "fdInfoDirInode", + }, +) + +go_template_instance( + name = "subtasks_inode_refs", + out = "subtasks_inode_refs.go", + package = "proc", + prefix = "subtasksInode", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "subtasksInode", + }, +) + +go_template_instance( + name = "task_inode_refs", + out = "task_inode_refs.go", + package = "proc", + prefix = "taskInode", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "taskInode", + }, +) + +go_template_instance( + name = "tasks_inode_refs", + out = "tasks_inode_refs.go", + package = "proc", + prefix = "tasksInode", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "tasksInode", + }, +) + go_library( name = "proc", srcs = [ + "fd_dir_inode_refs.go", + "fd_info_dir_inode_refs.go", "filesystem.go", "subtasks.go", + "subtasks_inode_refs.go", "task.go", "task_fds.go", "task_files.go", + "task_inode_refs.go", "task_net.go", "tasks.go", "tasks_files.go", + "tasks_inode_refs.go", "tasks_sys.go", ], visibility = ["//pkg/sentry:internal"], diff --git a/pkg/sentry/fsimpl/proc/subtasks.go b/pkg/sentry/fsimpl/proc/subtasks.go index f25747da3..01c0efb3a 100644 --- a/pkg/sentry/fsimpl/proc/subtasks.go +++ b/pkg/sentry/fsimpl/proc/subtasks.go @@ -31,6 +31,7 @@ import ( // // +stateify savable type subtasksInode struct { + subtasksInodeRefs kernfs.InodeNotSymlink kernfs.InodeDirectoryNoNewChildren kernfs.InodeAttrs @@ -57,6 +58,7 @@ func (fs *filesystem) newSubtasks(task *kernel.Task, pidns *kernel.PIDNamespace, // Note: credentials are overridden by taskOwnedInode. subInode.InodeAttrs.Init(task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) subInode.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) + subInode.EnableLeakCheck() inode := &taskOwnedInode{Inode: subInode, owner: task} dentry := &kernfs.Dentry{} @@ -182,3 +184,8 @@ func (i *subtasksInode) Stat(ctx context.Context, vsfs *vfs.Filesystem, opts vfs func (*subtasksInode) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.SetStatOptions) error { return syserror.EPERM } + +// DecRef implements kernfs.Inode. +func (i *subtasksInode) DecRef(context.Context) { + i.subtasksInodeRefs.DecRef(i.Destroy) +} diff --git a/pkg/sentry/fsimpl/proc/task.go b/pkg/sentry/fsimpl/proc/task.go index 109b31b4c..66b557abd 100644 --- a/pkg/sentry/fsimpl/proc/task.go +++ b/pkg/sentry/fsimpl/proc/task.go @@ -32,6 +32,7 @@ import ( // // +stateify savable type taskInode struct { + taskInodeRefs kernfs.InodeNotSymlink kernfs.InodeDirectoryNoNewChildren kernfs.InodeNoDynamicLookup @@ -84,6 +85,7 @@ func (fs *filesystem) newTaskInode(task *kernel.Task, pidns *kernel.PIDNamespace taskInode := &taskInode{task: task} // Note: credentials are overridden by taskOwnedInode. taskInode.InodeAttrs.Init(task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) + taskInode.EnableLeakCheck() inode := &taskOwnedInode{Inode: taskInode, owner: task} dentry := &kernfs.Dentry{} @@ -119,6 +121,11 @@ func (*taskInode) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, v return syserror.EPERM } +// DecRef implements kernfs.Inode. +func (i *taskInode) DecRef(context.Context) { + i.taskInodeRefs.DecRef(i.Destroy) +} + // taskOwnedInode implements kernfs.Inode and overrides inode owner with task // effective user and group. type taskOwnedInode struct { @@ -147,6 +154,7 @@ func (fs *filesystem) newTaskOwnedDir(task *kernel.Task, ino uint64, perm linux. dir.Init(task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, ino, perm, kernfs.GenericDirectoryFDOptions{ SeekEnd: kernfs.SeekEndZero, }) + dir.EnableLeakCheck() inode := &taskOwnedInode{Inode: dir, owner: task} d := &kernfs.Dentry{} diff --git a/pkg/sentry/fsimpl/proc/task_fds.go b/pkg/sentry/fsimpl/proc/task_fds.go index e8fcb9aa1..0527b2de8 100644 --- a/pkg/sentry/fsimpl/proc/task_fds.go +++ b/pkg/sentry/fsimpl/proc/task_fds.go @@ -22,7 +22,6 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" @@ -101,6 +100,7 @@ func (i *fdDir) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, off // // +stateify savable type fdDirInode struct { + fdDirInodeRefs kernfs.InodeNotSymlink kernfs.InodeDirectoryNoNewChildren kernfs.InodeAttrs @@ -120,6 +120,7 @@ func (fs *filesystem) newFDDirInode(task *kernel.Task) *kernfs.Dentry { }, } inode.InodeAttrs.Init(task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) + inode.EnableLeakCheck() dentry := &kernfs.Dentry{} dentry.Init(inode) @@ -175,6 +176,11 @@ func (i *fdDirInode) CheckPermissions(ctx context.Context, creds *auth.Credentia return err } +// DecRef implements kernfs.Inode. +func (i *fdDirInode) DecRef(context.Context) { + i.fdDirInodeRefs.DecRef(i.Destroy) +} + // fdSymlink is an symlink for the /proc/[pid]/fd/[fd] file. // // +stateify savable @@ -227,6 +233,7 @@ func (s *fdSymlink) Getlink(ctx context.Context, mnt *vfs.Mount) (vfs.VirtualDen // // +stateify savable type fdInfoDirInode struct { + fdInfoDirInodeRefs kernfs.InodeNotSymlink kernfs.InodeDirectoryNoNewChildren kernfs.InodeAttrs @@ -245,6 +252,7 @@ func (fs *filesystem) newFDInfoDirInode(task *kernel.Task) *kernfs.Dentry { }, } inode.InodeAttrs.Init(task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) + inode.EnableLeakCheck() dentry := &kernfs.Dentry{} dentry.Init(inode) @@ -282,12 +290,16 @@ func (i *fdInfoDirInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd * return fd.VFSFileDescription(), nil } +// DecRef implements kernfs.Inode. +func (i *fdInfoDirInode) DecRef(context.Context) { + i.fdInfoDirInodeRefs.DecRef(i.Destroy) +} + // fdInfoData implements vfs.DynamicBytesSource for /proc/[pid]/fdinfo/[fd]. // // +stateify savable type fdInfoData struct { kernfs.DynamicBytesFile - refs.AtomicRefCount task *kernel.Task fd int32 diff --git a/pkg/sentry/fsimpl/proc/task_net.go b/pkg/sentry/fsimpl/proc/task_net.go index a4c884bf9..4e69782c7 100644 --- a/pkg/sentry/fsimpl/proc/task_net.go +++ b/pkg/sentry/fsimpl/proc/task_net.go @@ -262,7 +262,7 @@ func (n *netUnixData) Generate(ctx context.Context, buf *bytes.Buffer) error { // For now, we always redact this pointer. fmt.Fprintf(buf, "%#016p: %08X %08X %08X %04X %02X %8d", (*unix.SocketOperations)(nil), // Num, pointer to kernel socket struct. - s.Refs()-1, // RefCount, don't count our own ref. + s.ReadRefs()-1, // RefCount, don't count our own ref. 0, // Protocol, always 0 for UDS. sockFlags, // Flags. sops.Endpoint().Type(), // Type. @@ -430,7 +430,7 @@ func commonGenerateTCP(ctx context.Context, buf *bytes.Buffer, k *kernel.Kernel, // Field: refcount. Don't count the ref we obtain while deferencing // the weakref to this socket. - fmt.Fprintf(buf, "%d ", s.Refs()-1) + fmt.Fprintf(buf, "%d ", s.ReadRefs()-1) // Field: Socket struct address. Redacted due to the same reason as // the 'Num' field in /proc/net/unix, see netUnix.ReadSeqFileData. @@ -589,7 +589,7 @@ func (d *netUDPData) Generate(ctx context.Context, buf *bytes.Buffer) error { // Field: ref; reference count on the socket inode. Don't count the ref // we obtain while deferencing the weakref to this socket. - fmt.Fprintf(buf, "%d ", s.Refs()-1) + fmt.Fprintf(buf, "%d ", s.ReadRefs()-1) // Field: Socket struct address. Redacted due to the same reason as // the 'Num' field in /proc/net/unix, see netUnix.ReadSeqFileData. diff --git a/pkg/sentry/fsimpl/proc/tasks.go b/pkg/sentry/fsimpl/proc/tasks.go index 1391992b7..863c4467e 100644 --- a/pkg/sentry/fsimpl/proc/tasks.go +++ b/pkg/sentry/fsimpl/proc/tasks.go @@ -37,6 +37,7 @@ const ( // // +stateify savable type tasksInode struct { + tasksInodeRefs kernfs.InodeNotSymlink kernfs.InodeDirectoryNoNewChildren kernfs.InodeAttrs @@ -84,6 +85,7 @@ func (fs *filesystem) newTasksInode(k *kernel.Kernel, pidns *kernel.PIDNamespace cgroupControllers: cgroupControllers, } inode.InodeAttrs.Init(root, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) + inode.EnableLeakCheck() dentry := &kernfs.Dentry{} dentry.Init(inode) @@ -226,6 +228,11 @@ func (i *tasksInode) Stat(ctx context.Context, vsfs *vfs.Filesystem, opts vfs.St return stat, nil } +// DecRef implements kernfs.Inode. +func (i *tasksInode) DecRef(context.Context) { + i.tasksInodeRefs.DecRef(i.Destroy) +} + // staticFileSetStat implements a special static file that allows inode // attributes to be set. This is to support /proc files that are readonly, but // allow attributes to be set. diff --git a/pkg/sentry/fsimpl/sys/BUILD b/pkg/sentry/fsimpl/sys/BUILD index f9b232da6..906cd52cb 100644 --- a/pkg/sentry/fsimpl/sys/BUILD +++ b/pkg/sentry/fsimpl/sys/BUILD @@ -1,10 +1,23 @@ load("//tools:defs.bzl", "go_library", "go_test") +load("//tools/go_generics:defs.bzl", "go_template_instance") licenses(["notice"]) +go_template_instance( + name = "dir_refs", + out = "dir_refs.go", + package = "sys", + prefix = "dir", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "dir", + }, +) + go_library( name = "sys", srcs = [ + "dir_refs.go", "kcov.go", "sys.go", ], @@ -13,6 +26,8 @@ go_library( "//pkg/abi/linux", "//pkg/context", "//pkg/coverage", + "//pkg/log", + "//pkg/refs", "//pkg/sentry/arch", "//pkg/sentry/fsimpl/kernfs", "//pkg/sentry/kernel", diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go index 1f042d9f7..ea30a4ec2 100644 --- a/pkg/sentry/fsimpl/sys/sys.go +++ b/pkg/sentry/fsimpl/sys/sys.go @@ -118,6 +118,7 @@ func (fs *filesystem) Release(ctx context.Context) { // dir implements kernfs.Inode. type dir struct { + dirRefs kernfs.InodeAttrs kernfs.InodeNoDynamicLookup kernfs.InodeNotSymlink @@ -133,6 +134,7 @@ func (fs *filesystem) newDir(creds *auth.Credentials, mode linux.FileMode, conte d := &dir{} d.InodeAttrs.Init(creds, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0755) d.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) + d.EnableLeakCheck() d.dentry.Init(d) d.IncLinks(d.OrderedChildren.Populate(&d.dentry, contents)) @@ -140,7 +142,7 @@ func (fs *filesystem) newDir(creds *auth.Credentials, mode linux.FileMode, conte return &d.dentry } -// SetStat implements Inode.SetStat not allowing inode attributes to be changed. +// SetStat implements kernfs.Inode.SetStat not allowing inode attributes to be changed. func (*dir) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.SetStatOptions) error { return syserror.EPERM } @@ -156,6 +158,11 @@ func (d *dir) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, return fd.VFSFileDescription(), nil } +// DecRef implements kernfs.Inode.DecRef. +func (d *dir) DecRef(context.Context) { + d.dirRefs.DecRef(d.Destroy) +} + // cpuFile implements kernfs.Inode. type cpuFile struct { kernfs.DynamicBytesFile diff --git a/pkg/sentry/kernel/BUILD b/pkg/sentry/kernel/BUILD index d1ecceba3..d436daab4 100644 --- a/pkg/sentry/kernel/BUILD +++ b/pkg/sentry/kernel/BUILD @@ -74,6 +74,50 @@ go_template_instance( }, ) +go_template_instance( + name = "fd_table_refs", + out = "fd_table_refs.go", + package = "kernel", + prefix = "FDTable", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "FDTable", + }, +) + +go_template_instance( + name = "fs_context_refs", + out = "fs_context_refs.go", + package = "kernel", + prefix = "FSContext", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "FSContext", + }, +) + +go_template_instance( + name = "process_group_refs", + out = "process_group_refs.go", + package = "kernel", + prefix = "ProcessGroup", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "ProcessGroup", + }, +) + +go_template_instance( + name = "session_refs", + out = "session_refs.go", + package = "kernel", + prefix = "Session", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "Session", + }, +) + proto_library( name = "uncaught_signal", srcs = ["uncaught_signal.proto"], @@ -88,8 +132,10 @@ go_library( "aio.go", "context.go", "fd_table.go", + "fd_table_refs.go", "fd_table_unsafe.go", "fs_context.go", + "fs_context_refs.go", "ipc_namespace.go", "kcov.go", "kcov_unsafe.go", @@ -101,6 +147,7 @@ go_library( "pending_signals_state.go", "posixtimer.go", "process_group_list.go", + "process_group_refs.go", "ptrace.go", "ptrace_amd64.go", "ptrace_arm64.go", @@ -108,6 +155,7 @@ go_library( "seccomp.go", "seqatomic_taskgoroutineschedinfo_unsafe.go", "session_list.go", + "session_refs.go", "sessions.go", "signal.go", "signal_handlers.go", diff --git a/pkg/sentry/kernel/fd_table.go b/pkg/sentry/kernel/fd_table.go index ce53af69b..5773244ac 100644 --- a/pkg/sentry/kernel/fd_table.go +++ b/pkg/sentry/kernel/fd_table.go @@ -23,7 +23,6 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/lock" "gvisor.dev/gvisor/pkg/sentry/limits" @@ -78,7 +77,8 @@ type descriptor struct { // // +stateify savable type FDTable struct { - refs.AtomicRefCount + FDTableRefs + k *Kernel // mu protects below. @@ -176,16 +176,15 @@ func (k *Kernel) NewFDTable() *FDTable { return f } -// destroy removes all of the file descriptors from the map. -func (f *FDTable) destroy(ctx context.Context) { - f.RemoveIf(ctx, func(*fs.File, *vfs.FileDescription, FDFlags) bool { - return true - }) -} - -// DecRef implements RefCounter.DecRef with destructor f.destroy. +// DecRef implements RefCounter.DecRef. +// +// If f reaches zero references, all of its file descriptors are removed. func (f *FDTable) DecRef(ctx context.Context) { - f.DecRefWithDestructor(ctx, f.destroy) + f.FDTableRefs.DecRef(func() { + f.RemoveIf(ctx, func(*fs.File, *vfs.FileDescription, FDFlags) bool { + return true + }) + }) } // Size returns the number of file descriptor slots currently allocated. diff --git a/pkg/sentry/kernel/fd_table_unsafe.go b/pkg/sentry/kernel/fd_table_unsafe.go index 7fd97dc53..6b8feb107 100644 --- a/pkg/sentry/kernel/fd_table_unsafe.go +++ b/pkg/sentry/kernel/fd_table_unsafe.go @@ -31,6 +31,8 @@ type descriptorTable struct { } // init initializes the table. +// +// TODO(gvisor.dev/1486): Enable leak check for FDTable. func (f *FDTable) init() { var slice []unsafe.Pointer // Empty slice. atomic.StorePointer(&f.slice, unsafe.Pointer(&slice)) diff --git a/pkg/sentry/kernel/fs_context.go b/pkg/sentry/kernel/fs_context.go index 8f2d36d5a..d46d1e1c1 100644 --- a/pkg/sentry/kernel/fs_context.go +++ b/pkg/sentry/kernel/fs_context.go @@ -18,7 +18,6 @@ import ( "fmt" "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/sync" @@ -30,7 +29,7 @@ import ( // // +stateify savable type FSContext struct { - refs.AtomicRefCount + FSContextRefs // mu protects below. mu sync.Mutex `state:"nosave"` @@ -64,7 +63,7 @@ func newFSContext(root, cwd *fs.Dirent, umask uint) *FSContext { cwd: cwd, umask: umask, } - f.EnableLeakCheck("kernel.FSContext") + f.EnableLeakCheck() return &f } @@ -77,54 +76,56 @@ func NewFSContextVFS2(root, cwd vfs.VirtualDentry, umask uint) *FSContext { cwdVFS2: cwd, umask: umask, } - f.EnableLeakCheck("kernel.FSContext") + f.EnableLeakCheck() return &f } -// destroy is the destructor for an FSContext. +// DecRef implements RefCounter.DecRef. // -// This will call DecRef on both root and cwd Dirents. If either call to -// DecRef returns an error, then it will be propagated. If both calls to -// DecRef return an error, then the one from root.DecRef will be propagated. +// When f reaches zero references, DecRef will be called on both root and cwd +// Dirents. // // Note that there may still be calls to WorkingDirectory() or RootDirectory() // (that return nil). This is because valid references may still be held via // proc files or other mechanisms. -func (f *FSContext) destroy(ctx context.Context) { - // Hold f.mu so that we don't race with RootDirectory() and - // WorkingDirectory(). - f.mu.Lock() - defer f.mu.Unlock() - - if VFS2Enabled { - f.rootVFS2.DecRef(ctx) - f.rootVFS2 = vfs.VirtualDentry{} - f.cwdVFS2.DecRef(ctx) - f.cwdVFS2 = vfs.VirtualDentry{} - } else { - f.root.DecRef(ctx) - f.root = nil - f.cwd.DecRef(ctx) - f.cwd = nil - } -} - -// DecRef implements RefCounter.DecRef with destructor f.destroy. func (f *FSContext) DecRef(ctx context.Context) { - f.DecRefWithDestructor(ctx, f.destroy) + f.FSContextRefs.DecRef(func() { + // Hold f.mu so that we don't race with RootDirectory() and + // WorkingDirectory(). + f.mu.Lock() + defer f.mu.Unlock() + + if VFS2Enabled { + f.rootVFS2.DecRef(ctx) + f.rootVFS2 = vfs.VirtualDentry{} + f.cwdVFS2.DecRef(ctx) + f.cwdVFS2 = vfs.VirtualDentry{} + } else { + f.root.DecRef(ctx) + f.root = nil + f.cwd.DecRef(ctx) + f.cwd = nil + } + }) } // Fork forks this FSContext. // -// This is not a valid call after destroy. +// This is not a valid call after f is destroyed. func (f *FSContext) Fork() *FSContext { f.mu.Lock() defer f.mu.Unlock() if VFS2Enabled { + if !f.cwdVFS2.Ok() { + panic("FSContext.Fork() called after destroy") + } f.cwdVFS2.IncRef() f.rootVFS2.IncRef() } else { + if f.cwd == nil { + panic("FSContext.Fork() called after destroy") + } f.cwd.IncRef() f.root.IncRef() } @@ -140,8 +141,8 @@ func (f *FSContext) Fork() *FSContext { // WorkingDirectory returns the current working directory. // -// This will return nil if called after destroy(), otherwise it will return a -// Dirent with a reference taken. +// This will return nil if called after f is destroyed, otherwise it will return +// a Dirent with a reference taken. func (f *FSContext) WorkingDirectory() *fs.Dirent { f.mu.Lock() defer f.mu.Unlock() @@ -152,8 +153,8 @@ func (f *FSContext) WorkingDirectory() *fs.Dirent { // WorkingDirectoryVFS2 returns the current working directory. // -// This will return nil if called after destroy(), otherwise it will return a -// Dirent with a reference taken. +// This will return nil if called after f is destroyed, otherwise it will return +// a Dirent with a reference taken. func (f *FSContext) WorkingDirectoryVFS2() vfs.VirtualDentry { f.mu.Lock() defer f.mu.Unlock() @@ -165,7 +166,7 @@ func (f *FSContext) WorkingDirectoryVFS2() vfs.VirtualDentry { // SetWorkingDirectory sets the current working directory. // This will take an extra reference on the Dirent. // -// This is not a valid call after destroy. +// This is not a valid call after f is destroyed. func (f *FSContext) SetWorkingDirectory(ctx context.Context, d *fs.Dirent) { if d == nil { panic("FSContext.SetWorkingDirectory called with nil dirent") @@ -187,11 +188,15 @@ func (f *FSContext) SetWorkingDirectory(ctx context.Context, d *fs.Dirent) { // SetWorkingDirectoryVFS2 sets the current working directory. // This will take an extra reference on the VirtualDentry. // -// This is not a valid call after destroy. +// This is not a valid call after f is destroyed. func (f *FSContext) SetWorkingDirectoryVFS2(ctx context.Context, d vfs.VirtualDentry) { f.mu.Lock() defer f.mu.Unlock() + if !f.cwdVFS2.Ok() { + panic(fmt.Sprintf("FSContext.SetWorkingDirectoryVFS2(%v)) called after destroy", d)) + } + old := f.cwdVFS2 f.cwdVFS2 = d d.IncRef() @@ -200,8 +205,8 @@ func (f *FSContext) SetWorkingDirectoryVFS2(ctx context.Context, d vfs.VirtualDe // RootDirectory returns the current filesystem root. // -// This will return nil if called after destroy(), otherwise it will return a -// Dirent with a reference taken. +// This will return nil if called after f is destroyed, otherwise it will return +// a Dirent with a reference taken. func (f *FSContext) RootDirectory() *fs.Dirent { f.mu.Lock() defer f.mu.Unlock() @@ -213,8 +218,8 @@ func (f *FSContext) RootDirectory() *fs.Dirent { // RootDirectoryVFS2 returns the current filesystem root. // -// This will return nil if called after destroy(), otherwise it will return a -// Dirent with a reference taken. +// This will return nil if called after f is destroyed, otherwise it will return +// a Dirent with a reference taken. func (f *FSContext) RootDirectoryVFS2() vfs.VirtualDentry { f.mu.Lock() defer f.mu.Unlock() @@ -226,7 +231,7 @@ func (f *FSContext) RootDirectoryVFS2() vfs.VirtualDentry { // SetRootDirectory sets the root directory. // This will take an extra reference on the Dirent. // -// This is not a valid call after free. +// This is not a valid call after f is destroyed. func (f *FSContext) SetRootDirectory(ctx context.Context, d *fs.Dirent) { if d == nil { panic("FSContext.SetRootDirectory called with nil dirent") @@ -247,7 +252,7 @@ func (f *FSContext) SetRootDirectory(ctx context.Context, d *fs.Dirent) { // SetRootDirectoryVFS2 sets the root directory. It takes a reference on vd. // -// This is not a valid call after free. +// This is not a valid call after f is destroyed. func (f *FSContext) SetRootDirectoryVFS2(ctx context.Context, vd vfs.VirtualDentry) { if !vd.Ok() { panic("FSContext.SetRootDirectoryVFS2 called with zero-value VirtualDentry") diff --git a/pkg/sentry/kernel/sessions.go b/pkg/sentry/kernel/sessions.go index 5c4c622c2..df5c8421b 100644 --- a/pkg/sentry/kernel/sessions.go +++ b/pkg/sentry/kernel/sessions.go @@ -16,8 +16,6 @@ package kernel import ( "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/syserror" ) @@ -32,7 +30,7 @@ type ProcessGroupID ThreadID // // +stateify savable type Session struct { - refs refs.AtomicRefCount + SessionRefs // leader is the originator of the Session. // @@ -62,16 +60,11 @@ type Session struct { sessionEntry } -// incRef grabs a reference. -func (s *Session) incRef() { - s.refs.IncRef() -} - -// decRef drops a reference. +// DecRef drops a reference. // // Precondition: callers must hold TaskSet.mu for writing. -func (s *Session) decRef() { - s.refs.DecRefWithDestructor(nil, func(context.Context) { +func (s *Session) DecRef() { + s.SessionRefs.DecRef(func() { // Remove translations from the leader. for ns := s.leader.pidns; ns != nil; ns = ns.parent { id := ns.sids[s] @@ -88,7 +81,7 @@ func (s *Session) decRef() { // // +stateify savable type ProcessGroup struct { - refs refs.AtomicRefCount // not exported. + refs ProcessGroupRefs // originator is the originator of the group. // @@ -163,7 +156,7 @@ func (pg *ProcessGroup) decRefWithParent(parentPG *ProcessGroup) { } alive := true - pg.refs.DecRefWithDestructor(nil, func(context.Context) { + pg.refs.DecRef(func() { alive = false // don't bother with handleOrphan. // Remove translations from the originator. @@ -175,7 +168,7 @@ func (pg *ProcessGroup) decRefWithParent(parentPG *ProcessGroup) { // Remove the list of process groups. pg.session.processGroups.Remove(pg) - pg.session.decRef() + pg.session.DecRef() }) if alive { pg.handleOrphan() @@ -302,7 +295,7 @@ func (tg *ThreadGroup) createSession() error { id: SessionID(id), leader: tg, } - s.refs.EnableLeakCheck("kernel.Session") + s.EnableLeakCheck() // Create a new ProcessGroup, belonging to that Session. // This also has a single reference (assigned below). @@ -316,7 +309,7 @@ func (tg *ThreadGroup) createSession() error { session: s, ancestors: 0, } - pg.refs.EnableLeakCheck("kernel.ProcessGroup") + pg.refs.EnableLeakCheck() // Tie them and return the result. s.processGroups.PushBack(pg) @@ -396,13 +389,13 @@ func (tg *ThreadGroup) CreateProcessGroup() error { // // We manually adjust the ancestors if the parent is in the same // session. - tg.processGroup.session.incRef() + tg.processGroup.session.IncRef() pg := ProcessGroup{ id: ProcessGroupID(id), originator: tg, session: tg.processGroup.session, } - pg.refs.EnableLeakCheck("kernel.ProcessGroup") + pg.refs.EnableLeakCheck() if tg.leader.parent != nil && tg.leader.parent.tg.processGroup.session == pg.session { pg.ancestors++ diff --git a/pkg/sentry/kernel/shm/BUILD b/pkg/sentry/kernel/shm/BUILD index c211fc8d0..b7e4b480d 100644 --- a/pkg/sentry/kernel/shm/BUILD +++ b/pkg/sentry/kernel/shm/BUILD @@ -1,12 +1,25 @@ load("//tools:defs.bzl", "go_library") +load("//tools/go_generics:defs.bzl", "go_template_instance") package(licenses = ["notice"]) +go_template_instance( + name = "shm_refs", + out = "shm_refs.go", + package = "shm", + prefix = "Shm", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "Shm", + }, +) + go_library( name = "shm", srcs = [ "device.go", "shm.go", + "shm_refs.go", ], visibility = ["//pkg/sentry:internal"], deps = [ diff --git a/pkg/sentry/kernel/shm/shm.go b/pkg/sentry/kernel/shm/shm.go index 13ec7afe0..00c03585e 100644 --- a/pkg/sentry/kernel/shm/shm.go +++ b/pkg/sentry/kernel/shm/shm.go @@ -39,7 +39,6 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/log" - "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time" @@ -252,7 +251,7 @@ func (r *Registry) newShm(ctx context.Context, pid int32, key Key, creator fs.Fi creatorPID: pid, changeTime: ktime.NowFromContext(ctx), } - shm.EnableLeakCheck("kernel.Shm") + shm.EnableLeakCheck() // Find the next available ID. for id := r.lastIDUsed + 1; id != r.lastIDUsed; id++ { @@ -337,14 +336,14 @@ func (r *Registry) remove(s *Shm) { // // +stateify savable type Shm struct { - // AtomicRefCount tracks the number of references to this segment. + // ShmRefs tracks the number of references to this segment. // // A segment holds a reference to itself until it is marked for // destruction. // // In addition to direct users, the MemoryManager will hold references // via MappingIdentity. - refs.AtomicRefCount + ShmRefs mfp pgalloc.MemoryFileProvider @@ -428,11 +427,14 @@ func (s *Shm) InodeID() uint64 { return uint64(s.ID) } -// DecRef overrides refs.RefCount.DecRef with a destructor. +// DecRef drops a reference on s. // // Precondition: Caller must not hold s.mu. func (s *Shm) DecRef(ctx context.Context) { - s.DecRefWithDestructor(ctx, s.destroy) + s.ShmRefs.DecRef(func() { + s.mfp.MemoryFile().DecRef(s.fr) + s.registry.remove(s) + }) } // Msync implements memmap.MappingIdentity.Msync. Msync is a no-op for shm @@ -642,11 +644,6 @@ func (s *Shm) Set(ctx context.Context, ds *linux.ShmidDS) error { return nil } -func (s *Shm) destroy(context.Context) { - s.mfp.MemoryFile().DecRef(s.fr) - s.registry.remove(s) -} - // MarkDestroyed marks a segment for destruction. The segment is actually // destroyed once it has no references. MarkDestroyed may be called multiple // times, and is safe to call after a segment has already been destroyed. See diff --git a/pkg/sentry/mm/BUILD b/pkg/sentry/mm/BUILD index f9d0837a1..b4a47ccca 100644 --- a/pkg/sentry/mm/BUILD +++ b/pkg/sentry/mm/BUILD @@ -73,12 +73,35 @@ go_template_instance( }, ) +go_template_instance( + name = "aio_mappable_refs", + out = "aio_mappable_refs.go", + package = "mm", + prefix = "aioMappable", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "aioMappable", + }, +) + +go_template_instance( + name = "special_mappable_refs", + out = "special_mappable_refs.go", + package = "mm", + prefix = "SpecialMappable", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "SpecialMappable", + }, +) + go_library( name = "mm", srcs = [ "address_space.go", "aio_context.go", "aio_context_state.go", + "aio_mappable_refs.go", "debug.go", "file_refcount_set.go", "io.go", @@ -92,6 +115,7 @@ go_library( "save_restore.go", "shm.go", "special_mappable.go", + "special_mappable_refs.go", "syscalls.go", "vma.go", "vma_set.go", diff --git a/pkg/sentry/mm/aio_context.go b/pkg/sentry/mm/aio_context.go index 16fea53c4..7bf48cb2c 100644 --- a/pkg/sentry/mm/aio_context.go +++ b/pkg/sentry/mm/aio_context.go @@ -17,7 +17,6 @@ package mm import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sentry/memmap" "gvisor.dev/gvisor/pkg/sentry/pgalloc" "gvisor.dev/gvisor/pkg/sentry/usage" @@ -239,7 +238,7 @@ func (ctx *AIOContext) Drain() { // // +stateify savable type aioMappable struct { - refs.AtomicRefCount + aioMappableRefs mfp pgalloc.MemoryFileProvider fr memmap.FileRange @@ -253,13 +252,13 @@ func newAIOMappable(mfp pgalloc.MemoryFileProvider) (*aioMappable, error) { return nil, err } m := aioMappable{mfp: mfp, fr: fr} - m.EnableLeakCheck("mm.aioMappable") + m.EnableLeakCheck() return &m, nil } // DecRef implements refs.RefCounter.DecRef. func (m *aioMappable) DecRef(ctx context.Context) { - m.AtomicRefCount.DecRefWithDestructor(ctx, func(context.Context) { + m.aioMappableRefs.DecRef(func() { m.mfp.MemoryFile().DecRef(m.fr) }) } diff --git a/pkg/sentry/mm/special_mappable.go b/pkg/sentry/mm/special_mappable.go index 4cdb52eb6..f4c93baeb 100644 --- a/pkg/sentry/mm/special_mappable.go +++ b/pkg/sentry/mm/special_mappable.go @@ -16,7 +16,6 @@ package mm import ( "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sentry/memmap" "gvisor.dev/gvisor/pkg/sentry/pgalloc" "gvisor.dev/gvisor/pkg/sentry/usage" @@ -31,7 +30,7 @@ import ( // // +stateify savable type SpecialMappable struct { - refs.AtomicRefCount + SpecialMappableRefs mfp pgalloc.MemoryFileProvider fr memmap.FileRange @@ -45,13 +44,13 @@ type SpecialMappable struct { // Preconditions: fr.Length() != 0. func NewSpecialMappable(name string, mfp pgalloc.MemoryFileProvider, fr memmap.FileRange) *SpecialMappable { m := SpecialMappable{mfp: mfp, fr: fr, name: name} - m.EnableLeakCheck("mm.SpecialMappable") + m.EnableLeakCheck() return &m } // DecRef implements refs.RefCounter.DecRef. func (m *SpecialMappable) DecRef(ctx context.Context) { - m.AtomicRefCount.DecRefWithDestructor(ctx, func(context.Context) { + m.SpecialMappableRefs.DecRef(func() { m.mfp.MemoryFile().DecRef(m.fr) }) } diff --git a/pkg/sentry/socket/unix/transport/BUILD b/pkg/sentry/socket/unix/transport/BUILD index c708b6030..26c3a51b9 100644 --- a/pkg/sentry/socket/unix/transport/BUILD +++ b/pkg/sentry/socket/unix/transport/BUILD @@ -15,6 +15,17 @@ go_template_instance( }, ) +go_template_instance( + name = "queue_refs", + out = "queue_refs.go", + package = "transport", + prefix = "queue", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "queue", + }, +) + go_library( name = "transport", srcs = [ @@ -22,6 +33,7 @@ go_library( "connectioned_state.go", "connectionless.go", "queue.go", + "queue_refs.go", "transport_message_list.go", "unix.go", ], diff --git a/pkg/sentry/socket/unix/transport/connectioned.go b/pkg/sentry/socket/unix/transport/connectioned.go index c67b602f0..e3a75b519 100644 --- a/pkg/sentry/socket/unix/transport/connectioned.go +++ b/pkg/sentry/socket/unix/transport/connectioned.go @@ -142,9 +142,9 @@ func NewPair(ctx context.Context, stype linux.SockType, uid UniqueIDProvider) (E } q1 := &queue{ReaderQueue: a.Queue, WriterQueue: b.Queue, limit: initialLimit} - q1.EnableLeakCheck("transport.queue") + q1.EnableLeakCheck() q2 := &queue{ReaderQueue: b.Queue, WriterQueue: a.Queue, limit: initialLimit} - q2.EnableLeakCheck("transport.queue") + q2.EnableLeakCheck() if stype == linux.SOCK_STREAM { a.receiver = &streamQueueReceiver{queueReceiver: queueReceiver{q1}} @@ -300,14 +300,14 @@ func (e *connectionedEndpoint) BidirectionalConnect(ctx context.Context, ce Conn } readQueue := &queue{ReaderQueue: ce.WaiterQueue(), WriterQueue: ne.Queue, limit: initialLimit} - readQueue.EnableLeakCheck("transport.queue") + readQueue.EnableLeakCheck() ne.connected = &connectedEndpoint{ endpoint: ce, writeQueue: readQueue, } writeQueue := &queue{ReaderQueue: ne.Queue, WriterQueue: ce.WaiterQueue(), limit: initialLimit} - writeQueue.EnableLeakCheck("transport.queue") + writeQueue.EnableLeakCheck() if e.stype == linux.SOCK_STREAM { ne.receiver = &streamQueueReceiver{queueReceiver: queueReceiver{readQueue: writeQueue}} } else { diff --git a/pkg/sentry/socket/unix/transport/connectionless.go b/pkg/sentry/socket/unix/transport/connectionless.go index 70ee8f9b8..4751b2fd8 100644 --- a/pkg/sentry/socket/unix/transport/connectionless.go +++ b/pkg/sentry/socket/unix/transport/connectionless.go @@ -42,7 +42,7 @@ var ( func NewConnectionless(ctx context.Context) Endpoint { ep := &connectionlessEndpoint{baseEndpoint{Queue: &waiter.Queue{}}} q := queue{ReaderQueue: ep.Queue, WriterQueue: &waiter.Queue{}, limit: initialLimit} - q.EnableLeakCheck("transport.queue") + q.EnableLeakCheck() ep.receiver = &queueReceiver{readQueue: &q} return ep } diff --git a/pkg/sentry/socket/unix/transport/queue.go b/pkg/sentry/socket/unix/transport/queue.go index ef6043e19..342def28f 100644 --- a/pkg/sentry/socket/unix/transport/queue.go +++ b/pkg/sentry/socket/unix/transport/queue.go @@ -16,7 +16,6 @@ package transport import ( "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserr" "gvisor.dev/gvisor/pkg/tcpip" @@ -28,7 +27,7 @@ import ( // // +stateify savable type queue struct { - refs.AtomicRefCount + queueRefs ReaderQueue *waiter.Queue WriterQueue *waiter.Queue @@ -68,11 +67,13 @@ func (q *queue) Reset(ctx context.Context) { q.mu.Unlock() } -// DecRef implements RefCounter.DecRef with destructor q.Reset. +// DecRef implements RefCounter.DecRef. func (q *queue) DecRef(ctx context.Context) { - q.DecRefWithDestructor(ctx, q.Reset) - // We don't need to notify after resetting because no one cares about - // this queue after all references have been dropped. + q.queueRefs.DecRef(func() { + // We don't need to notify after resetting because no one cares about + // this queue after all references have been dropped. + q.Reset(ctx) + }) } // IsReadable determines if q is currently readable. diff --git a/pkg/sentry/vfs/BUILD b/pkg/sentry/vfs/BUILD index 642769e7c..8093ca55c 100644 --- a/pkg/sentry/vfs/BUILD +++ b/pkg/sentry/vfs/BUILD @@ -27,6 +27,39 @@ go_template_instance( }, ) +go_template_instance( + name = "file_description_refs", + out = "file_description_refs.go", + package = "vfs", + prefix = "FileDescription", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "FileDescription", + }, +) + +go_template_instance( + name = "mount_namespace_refs", + out = "mount_namespace_refs.go", + package = "vfs", + prefix = "MountNamespace", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "MountNamespace", + }, +) + +go_template_instance( + name = "filesystem_refs", + out = "filesystem_refs.go", + package = "vfs", + prefix = "Filesystem", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "Filesystem", + }, +) + go_library( name = "vfs", srcs = [ @@ -40,12 +73,15 @@ go_library( "event_list.go", "file_description.go", "file_description_impl_util.go", + "file_description_refs.go", "filesystem.go", "filesystem_impl_util.go", + "filesystem_refs.go", "filesystem_type.go", "inotify.go", "lock.go", "mount.go", + "mount_namespace_refs.go", "mount_unsafe.go", "options.go", "pathname.go", @@ -63,6 +99,7 @@ go_library( "//pkg/fspath", "//pkg/gohacks", "//pkg/log", + "//pkg/refs", "//pkg/safemem", "//pkg/sentry/arch", "//pkg/sentry/fs", diff --git a/pkg/sentry/vfs/README.md b/pkg/sentry/vfs/README.md index 4b9faf2ea..5aad31b78 100644 --- a/pkg/sentry/vfs/README.md +++ b/pkg/sentry/vfs/README.md @@ -184,12 +184,3 @@ This construction, which is essentially a type-safe analogue to Linux's - File locking - `O_ASYNC` - -- Reference counts in the `vfs` package do not use the `refs` package since - `refs.AtomicRefCount` adds 64 bytes of overhead to each 8-byte reference - count, resulting in considerable cache bloat. 24 bytes of this overhead is - for weak reference support, which have poor performance and will not be used - by VFS2. The remaining 40 bytes is to store a descriptive string and stack - trace for reference leak checking; we can support reference leak checking - without incurring this space overhead by including the applicable - information directly in finalizers for applicable types. diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go index 3219a9e13..22a54fa48 100644 --- a/pkg/sentry/vfs/file_description.go +++ b/pkg/sentry/vfs/file_description.go @@ -38,9 +38,7 @@ import ( // // FileDescription is analogous to Linux's struct file. type FileDescription struct { - // refs is the reference count. refs is accessed using atomic memory - // operations. - refs int64 + FileDescriptionRefs // flagsMu protects statusFlags and asyncHandler below. flagsMu sync.Mutex @@ -131,7 +129,7 @@ func (fd *FileDescription) Init(impl FileDescriptionImpl, flags uint32, mnt *Mou } } - fd.refs = 1 + fd.EnableLeakCheck() // Remove "file creation flags" to mirror the behavior from file.f_flags in // fs/open.c:do_dentry_open. @@ -149,30 +147,9 @@ func (fd *FileDescription) Init(impl FileDescriptionImpl, flags uint32, mnt *Mou return nil } -// IncRef increments fd's reference count. -func (fd *FileDescription) IncRef() { - atomic.AddInt64(&fd.refs, 1) -} - -// TryIncRef increments fd's reference count and returns true. If fd's -// reference count is already zero, TryIncRef does nothing and returns false. -// -// TryIncRef does not require that a reference is held on fd. -func (fd *FileDescription) TryIncRef() bool { - for { - refs := atomic.LoadInt64(&fd.refs) - if refs <= 0 { - return false - } - if atomic.CompareAndSwapInt64(&fd.refs, refs, refs+1) { - return true - } - } -} - // DecRef decrements fd's reference count. func (fd *FileDescription) DecRef(ctx context.Context) { - if refs := atomic.AddInt64(&fd.refs, -1); refs == 0 { + fd.FileDescriptionRefs.DecRef(func() { // Unregister fd from all epoll instances. fd.epollMu.Lock() epolls := fd.epolls @@ -208,15 +185,7 @@ func (fd *FileDescription) DecRef(ctx context.Context) { } fd.asyncHandler = nil fd.flagsMu.Unlock() - } else if refs < 0 { - panic("FileDescription.DecRef() called without holding a reference") - } -} - -// Refs returns the current number of references. The returned count -// is inherently racy and is unsafe to use without external synchronization. -func (fd *FileDescription) Refs() int64 { - return atomic.LoadInt64(&fd.refs) + }) } // Mount returns the mount on which fd was opened. It does not take a reference diff --git a/pkg/sentry/vfs/filesystem.go b/pkg/sentry/vfs/filesystem.go index 2c60cfab2..46851f638 100644 --- a/pkg/sentry/vfs/filesystem.go +++ b/pkg/sentry/vfs/filesystem.go @@ -15,8 +15,6 @@ package vfs import ( - "sync/atomic" - "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/fspath" @@ -34,9 +32,7 @@ import ( // // +stateify savable type Filesystem struct { - // refs is the reference count. refs is accessed using atomic memory - // operations. - refs int64 + FilesystemRefs // vfs is the VirtualFilesystem that uses this Filesystem. vfs is // immutable. @@ -52,7 +48,7 @@ type Filesystem struct { // Init must be called before first use of fs. func (fs *Filesystem) Init(vfsObj *VirtualFilesystem, fsType FilesystemType, impl FilesystemImpl) { - fs.refs = 1 + fs.EnableLeakCheck() fs.vfs = vfsObj fs.fsType = fsType fs.impl = impl @@ -76,39 +72,14 @@ func (fs *Filesystem) Impl() FilesystemImpl { return fs.impl } -// IncRef increments fs' reference count. -func (fs *Filesystem) IncRef() { - if atomic.AddInt64(&fs.refs, 1) <= 1 { - panic("Filesystem.IncRef() called without holding a reference") - } -} - -// TryIncRef increments fs' reference count and returns true. If fs' reference -// count is zero, TryIncRef does nothing and returns false. -// -// TryIncRef does not require that a reference is held on fs. -func (fs *Filesystem) TryIncRef() bool { - for { - refs := atomic.LoadInt64(&fs.refs) - if refs <= 0 { - return false - } - if atomic.CompareAndSwapInt64(&fs.refs, refs, refs+1) { - return true - } - } -} - // DecRef decrements fs' reference count. func (fs *Filesystem) DecRef(ctx context.Context) { - if refs := atomic.AddInt64(&fs.refs, -1); refs == 0 { + fs.FilesystemRefs.DecRef(func() { fs.vfs.filesystemsMu.Lock() delete(fs.vfs.filesystems, fs) fs.vfs.filesystemsMu.Unlock() fs.impl.Release(ctx) - } else if refs < 0 { - panic("Filesystem.decRef() called without holding a reference") - } + }) } // FilesystemImpl contains implementation details for a Filesystem. diff --git a/pkg/sentry/vfs/mount.go b/pkg/sentry/vfs/mount.go index cd5456eef..db5fb3bb1 100644 --- a/pkg/sentry/vfs/mount.go +++ b/pkg/sentry/vfs/mount.go @@ -128,16 +128,14 @@ func (mnt *Mount) Options() MountOptions { // // +stateify savable type MountNamespace struct { + MountNamespaceRefs + // Owner is the usernamespace that owns this mount namespace. Owner *auth.UserNamespace // root is the MountNamespace's root mount. root is immutable. root *Mount - // refs is the reference count. refs is accessed using atomic memory - // operations. - refs int64 - // mountpoints maps all Dentries which are mount points in this namespace // to the number of Mounts for which they are mount points. mountpoints is // protected by VirtualFilesystem.mountMu. @@ -168,9 +166,9 @@ func (vfs *VirtualFilesystem) NewMountNamespace(ctx context.Context, creds *auth } mntns := &MountNamespace{ Owner: creds.UserNamespace, - refs: 1, mountpoints: make(map[*Dentry]uint32), } + mntns.EnableLeakCheck() mntns.root = newMount(vfs, fs, root, mntns, &MountOptions{}) return mntns, nil } @@ -509,17 +507,10 @@ func (mnt *Mount) DecRef(ctx context.Context) { } } -// IncRef increments mntns' reference count. -func (mntns *MountNamespace) IncRef() { - if atomic.AddInt64(&mntns.refs, 1) <= 1 { - panic("MountNamespace.IncRef() called without holding a reference") - } -} - // DecRef decrements mntns' reference count. func (mntns *MountNamespace) DecRef(ctx context.Context) { vfs := mntns.root.fs.VirtualFilesystem() - if refs := atomic.AddInt64(&mntns.refs, -1); refs == 0 { + mntns.MountNamespaceRefs.DecRef(func() { vfs.mountMu.Lock() vfs.mounts.seq.BeginWrite() vdsToDecRef, mountsToDecRef := vfs.umountRecursiveLocked(mntns.root, &umountRecursiveOptions{ @@ -533,9 +524,7 @@ func (mntns *MountNamespace) DecRef(ctx context.Context) { for _, mnt := range mountsToDecRef { mnt.DecRef(ctx) } - } else if refs < 0 { - panic("MountNamespace.DecRef() called without holding a reference") - } + }) } // getMountAt returns the last Mount in the stack mounted at (mnt, d). It takes diff --git a/pkg/tcpip/link/tun/BUILD b/pkg/tcpip/link/tun/BUILD index 6c137f693..0243424f6 100644 --- a/pkg/tcpip/link/tun/BUILD +++ b/pkg/tcpip/link/tun/BUILD @@ -1,18 +1,32 @@ load("//tools:defs.bzl", "go_library") +load("//tools/go_generics:defs.bzl", "go_template_instance") package(licenses = ["notice"]) +go_template_instance( + name = "tun_endpoint_refs", + out = "tun_endpoint_refs.go", + package = "tun", + prefix = "tunEndpoint", + template = "//pkg/refs_vfs2:refs_template", + types = { + "T": "tunEndpoint", + }, +) + go_library( name = "tun", srcs = [ "device.go", "protocol.go", + "tun_endpoint_refs.go", "tun_unsafe.go", ], visibility = ["//visibility:public"], deps = [ "//pkg/abi/linux", "//pkg/context", + "//pkg/log", "//pkg/refs", "//pkg/sync", "//pkg/syserror", diff --git a/pkg/tcpip/link/tun/device.go b/pkg/tcpip/link/tun/device.go index 3b1510a33..b6ddbe81e 100644 --- a/pkg/tcpip/link/tun/device.go +++ b/pkg/tcpip/link/tun/device.go @@ -19,7 +19,6 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/refs" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/tcpip" @@ -135,6 +134,7 @@ func attachOrCreateNIC(s *stack.Stack, name, prefix string, linkCaps stack.LinkE // 2. Creating a new NIC. id := tcpip.NICID(s.UniqueID()) + // TODO(gvisor.dev/1486): enable leak check for tunEndpoint. endpoint := &tunEndpoint{ Endpoint: channel.New(defaultDevOutQueueLen, defaultDevMtu, ""), stack: s, @@ -331,19 +331,18 @@ func (d *Device) WriteNotify() { // It is ref-counted as multiple opening files can attach to the same NIC. // The last owner is responsible for deleting the NIC. type tunEndpoint struct { + tunEndpointRefs *channel.Endpoint - refs.AtomicRefCount - stack *stack.Stack nicID tcpip.NICID name string isTap bool } -// DecRef decrements refcount of e, removes NIC if refcount goes to 0. +// DecRef decrements refcount of e, removing NIC if it reaches 0. func (e *tunEndpoint) DecRef(ctx context.Context) { - e.DecRefWithDestructor(ctx, func(context.Context) { + e.tunEndpointRefs.DecRef(func() { e.stack.RemoveNIC(e.nicID) }) } -- cgit v1.2.3 From 8d75fc4883ca8c10fb615203993d56d33a9e36b6 Mon Sep 17 00:00:00 2001 From: Rahat Mahmood Date: Fri, 28 Aug 2020 14:29:16 -0700 Subject: Implement StatFS for various VFS2 filesystems. This mainly involved enabling kernfs' client filesystems to provide a StatFS implementation. Fixes #3411, #3515. PiperOrigin-RevId: 329009864 --- pkg/abi/linux/fs.go | 1 + pkg/sentry/fsimpl/devpts/devpts.go | 10 +++++++++- pkg/sentry/fsimpl/devpts/master.go | 1 + pkg/sentry/fsimpl/devpts/slave.go | 1 + pkg/sentry/fsimpl/fuse/fusefs.go | 8 +++++++- pkg/sentry/fsimpl/host/host.go | 1 + pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go | 1 + pkg/sentry/fsimpl/kernfs/filesystem.go | 5 ++--- pkg/sentry/fsimpl/kernfs/inode_impl_util.go | 16 +++++++++++++--- pkg/sentry/fsimpl/kernfs/kernfs.go | 5 +++++ pkg/sentry/fsimpl/kernfs/kernfs_test.go | 8 +++++--- pkg/sentry/fsimpl/kernfs/symlink.go | 1 + pkg/sentry/fsimpl/pipefs/pipefs.go | 8 +++++--- pkg/sentry/fsimpl/proc/filesystem.go | 7 +++++++ pkg/sentry/fsimpl/proc/subtasks.go | 9 +++++---- pkg/sentry/fsimpl/proc/task.go | 7 ++++--- pkg/sentry/fsimpl/proc/task_fds.go | 19 +++++++++++-------- pkg/sentry/fsimpl/proc/task_files.go | 2 ++ pkg/sentry/fsimpl/proc/tasks.go | 9 +++++---- pkg/sentry/fsimpl/proc/tasks_files.go | 2 ++ pkg/sentry/fsimpl/sockfs/sockfs.go | 9 +++++++-- pkg/sentry/fsimpl/sys/kcov.go | 3 ++- pkg/sentry/fsimpl/sys/sys.go | 14 ++++++++++++++ pkg/sentry/vfs/filesystem_impl_util.go | 13 +++++++++++++ test/syscalls/BUILD | 1 + test/syscalls/linux/pipe.cc | 12 ++++++++++++ test/syscalls/linux/proc.cc | 14 ++++++++++++++ test/syscalls/linux/socket.cc | 17 +++++++++++++++++ test/syscalls/linux/statfs.cc | 16 ++++++++++------ 29 files changed, 178 insertions(+), 42 deletions(-) (limited to 'pkg/sentry/fsimpl/sys') diff --git a/pkg/abi/linux/fs.go b/pkg/abi/linux/fs.go index 2b1ef0d4e..0d921ed6f 100644 --- a/pkg/abi/linux/fs.go +++ b/pkg/abi/linux/fs.go @@ -29,6 +29,7 @@ const ( SYSFS_MAGIC = 0x62656572 TMPFS_MAGIC = 0x01021994 V9FS_MAGIC = 0x01021997 + FUSE_SUPER_MAGIC = 0x65735546 ) // Filesystem path limits, from uapi/linux/limits.h. diff --git a/pkg/sentry/fsimpl/devpts/devpts.go b/pkg/sentry/fsimpl/devpts/devpts.go index 0eaff9087..57580f4d4 100644 --- a/pkg/sentry/fsimpl/devpts/devpts.go +++ b/pkg/sentry/fsimpl/devpts/devpts.go @@ -111,12 +111,13 @@ func (fs *filesystem) Release(ctx context.Context) { // rootInode is the root directory inode for the devpts mounts. type rootInode struct { - rootInodeRefs + implStatFS kernfs.AlwaysValid kernfs.InodeAttrs kernfs.InodeDirectoryNoNewChildren kernfs.InodeNotSymlink kernfs.OrderedChildren + rootInodeRefs locks vfs.FileLocks @@ -240,3 +241,10 @@ func (i *rootInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, func (i *rootInode) DecRef(context.Context) { i.rootInodeRefs.DecRef(i.Destroy) } + +type implStatFS struct{} + +// StatFS implements kernfs.Inode.StatFS. +func (*implStatFS) StatFS(context.Context, *vfs.Filesystem) (linux.Statfs, error) { + return vfs.GenericStatFS(linux.DEVPTS_SUPER_MAGIC), nil +} diff --git a/pkg/sentry/fsimpl/devpts/master.go b/pkg/sentry/fsimpl/devpts/master.go index 3bb397f71..60feb1993 100644 --- a/pkg/sentry/fsimpl/devpts/master.go +++ b/pkg/sentry/fsimpl/devpts/master.go @@ -30,6 +30,7 @@ import ( // masterInode is the inode for the master end of the Terminal. type masterInode struct { + implStatFS kernfs.InodeAttrs kernfs.InodeNoopRefCount kernfs.InodeNotDirectory diff --git a/pkg/sentry/fsimpl/devpts/slave.go b/pkg/sentry/fsimpl/devpts/slave.go index 32e4e1908..a9da7af64 100644 --- a/pkg/sentry/fsimpl/devpts/slave.go +++ b/pkg/sentry/fsimpl/devpts/slave.go @@ -29,6 +29,7 @@ import ( // slaveInode is the inode for the slave end of the Terminal. type slaveInode struct { + implStatFS kernfs.InodeAttrs kernfs.InodeNoopRefCount kernfs.InodeNotDirectory diff --git a/pkg/sentry/fsimpl/fuse/fusefs.go b/pkg/sentry/fsimpl/fuse/fusefs.go index 9717c0e15..810819ae4 100644 --- a/pkg/sentry/fsimpl/fuse/fusefs.go +++ b/pkg/sentry/fsimpl/fuse/fusefs.go @@ -200,9 +200,9 @@ func (fs *filesystem) Release(ctx context.Context) { type inode struct { inodeRefs kernfs.InodeAttrs + kernfs.InodeDirectoryNoNewChildren kernfs.InodeNoDynamicLookup kernfs.InodeNotSymlink - kernfs.InodeDirectoryNoNewChildren kernfs.OrderedChildren locks vfs.FileLocks @@ -331,3 +331,9 @@ func (i *inode) Stat(ctx context.Context, fs *vfs.Filesystem, opts vfs.StatOptio func (i *inode) DecRef(context.Context) { i.inodeRefs.DecRef(i.Destroy) } + +// StatFS implements kernfs.Inode.StatFS. +func (i *inode) StatFS(ctx context.Context, fs *vfs.Filesystem) (linux.Statfs, error) { + // TODO(gvisor.dev/issues/3413): Complete the implementation of statfs. + return vfs.GenericStatFS(linux.FUSE_SUPER_MAGIC), nil +} diff --git a/pkg/sentry/fsimpl/host/host.go b/pkg/sentry/fsimpl/host/host.go index 2d3821f33..7561f821c 100644 --- a/pkg/sentry/fsimpl/host/host.go +++ b/pkg/sentry/fsimpl/host/host.go @@ -186,6 +186,7 @@ func (fs *filesystem) PrependPath(ctx context.Context, vfsroot, vd vfs.VirtualDe // inode implements kernfs.Inode. type inode struct { + kernfs.InodeNoStatFS kernfs.InodeNotDirectory kernfs.InodeNotSymlink diff --git a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go index 12adf727a..1ee089620 100644 --- a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go +++ b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go @@ -35,6 +35,7 @@ import ( // +stateify savable type DynamicBytesFile struct { InodeAttrs + InodeNoStatFS InodeNoopRefCount InodeNotDirectory InodeNotSymlink diff --git a/pkg/sentry/fsimpl/kernfs/filesystem.go b/pkg/sentry/fsimpl/kernfs/filesystem.go index e5d6b5c35..0e3011689 100644 --- a/pkg/sentry/fsimpl/kernfs/filesystem.go +++ b/pkg/sentry/fsimpl/kernfs/filesystem.go @@ -721,14 +721,13 @@ func (fs *Filesystem) StatAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf // StatFSAt implements vfs.FilesystemImpl.StatFSAt. func (fs *Filesystem) StatFSAt(ctx context.Context, rp *vfs.ResolvingPath) (linux.Statfs, error) { fs.mu.RLock() - _, _, err := fs.walkExistingLocked(ctx, rp) + _, inode, err := fs.walkExistingLocked(ctx, rp) fs.mu.RUnlock() fs.processDeferredDecRefs(ctx) if err != nil { return linux.Statfs{}, err } - // TODO(gvisor.dev/issue/1193): actually implement statfs. - return linux.Statfs{}, syserror.ENOSYS + return inode.StatFS(ctx, fs.VFSFilesystem()) } // SymlinkAt implements vfs.FilesystemImpl.SymlinkAt. diff --git a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go index f442a5606..c0b863ba4 100644 --- a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go +++ b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go @@ -546,12 +546,13 @@ func (InodeSymlink) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.D // // +stateify savable type StaticDirectory struct { - StaticDirectoryRefs - InodeNotSymlink - InodeDirectoryNoNewChildren InodeAttrs + InodeDirectoryNoNewChildren InodeNoDynamicLookup + InodeNoStatFS + InodeNotSymlink OrderedChildren + StaticDirectoryRefs locks vfs.FileLocks fdOpts GenericDirectoryFDOptions @@ -609,3 +610,12 @@ type AlwaysValid struct{} func (*AlwaysValid) Valid(context.Context) bool { return true } + +// InodeNoStatFS partially implements the Inode interface, where the client +// filesystem doesn't support statfs(2). +type InodeNoStatFS struct{} + +// StatFS implements Inode.StatFS. +func (*InodeNoStatFS) StatFS(context.Context, *vfs.Filesystem) (linux.Statfs, error) { + return linux.Statfs{}, syserror.ENOSYS +} diff --git a/pkg/sentry/fsimpl/kernfs/kernfs.go b/pkg/sentry/fsimpl/kernfs/kernfs.go index ca3685800..88fcd54aa 100644 --- a/pkg/sentry/fsimpl/kernfs/kernfs.go +++ b/pkg/sentry/fsimpl/kernfs/kernfs.go @@ -320,6 +320,11 @@ type Inode interface { // Precondition: rp.Done(). vfsd.Impl() must be the kernfs Dentry containing // the inode on which Open() is being called. Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) + + // StatFS returns filesystem statistics for the client filesystem. This + // corresponds to vfs.FilesystemImpl.StatFSAt. If the client filesystem + // doesn't support statfs(2), this should return ENOSYS. + StatFS(ctx context.Context, fs *vfs.Filesystem) (linux.Statfs, error) } type inodeRefs interface { diff --git a/pkg/sentry/fsimpl/kernfs/kernfs_test.go b/pkg/sentry/fsimpl/kernfs/kernfs_test.go index e376d1736..675587c6b 100644 --- a/pkg/sentry/fsimpl/kernfs/kernfs_test.go +++ b/pkg/sentry/fsimpl/kernfs/kernfs_test.go @@ -98,9 +98,10 @@ func (*attrs) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.S type readonlyDir struct { readonlyDirRefs attrs - kernfs.InodeNotSymlink - kernfs.InodeNoDynamicLookup kernfs.InodeDirectoryNoNewChildren + kernfs.InodeNoDynamicLookup + kernfs.InodeNoStatFS + kernfs.InodeNotSymlink kernfs.OrderedChildren locks vfs.FileLocks @@ -137,9 +138,10 @@ func (d *readonlyDir) DecRef(context.Context) { type dir struct { dirRefs attrs - kernfs.InodeNotSymlink kernfs.InodeNoDynamicLookup + kernfs.InodeNotSymlink kernfs.OrderedChildren + kernfs.InodeNoStatFS locks vfs.FileLocks diff --git a/pkg/sentry/fsimpl/kernfs/symlink.go b/pkg/sentry/fsimpl/kernfs/symlink.go index 2ab3f53fd..64731a3e4 100644 --- a/pkg/sentry/fsimpl/kernfs/symlink.go +++ b/pkg/sentry/fsimpl/kernfs/symlink.go @@ -28,6 +28,7 @@ type StaticSymlink struct { InodeAttrs InodeNoopRefCount InodeSymlink + InodeNoStatFS target string } diff --git a/pkg/sentry/fsimpl/pipefs/pipefs.go b/pkg/sentry/fsimpl/pipefs/pipefs.go index 2ca793db9..7053ad6db 100644 --- a/pkg/sentry/fsimpl/pipefs/pipefs.go +++ b/pkg/sentry/fsimpl/pipefs/pipefs.go @@ -143,14 +143,16 @@ func (i *inode) SetStat(ctx context.Context, vfsfs *vfs.Filesystem, creds *auth. return syserror.EPERM } -// TODO(gvisor.dev/issue/1193): kernfs does not provide a way to implement -// statfs, from which we should indicate PIPEFS_MAGIC. - // Open implements kernfs.Inode.Open. func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { return i.pipe.Open(ctx, rp.Mount(), vfsd, opts.Flags, &i.locks) } +// StatFS implements kernfs.Inode.StatFS. +func (i *inode) StatFS(ctx context.Context, fs *vfs.Filesystem) (linux.Statfs, error) { + return vfs.GenericStatFS(linux.PIPEFS_MAGIC), nil +} + // NewConnectedPipeFDs returns a pair of FileDescriptions representing the read // and write ends of a newly-created pipe, as for pipe(2) and pipe2(2). // diff --git a/pkg/sentry/fsimpl/proc/filesystem.go b/pkg/sentry/fsimpl/proc/filesystem.go index c350ec127..03b5941b9 100644 --- a/pkg/sentry/fsimpl/proc/filesystem.go +++ b/pkg/sentry/fsimpl/proc/filesystem.go @@ -121,3 +121,10 @@ func newStaticDir(creds *auth.Credentials, devMajor, devMinor uint32, ino uint64 type InternalData struct { Cgroups map[string]string } + +type implStatFS struct{} + +// StatFS implements kernfs.Inode.StatFS. +func (*implStatFS) StatFS(context.Context, *vfs.Filesystem) (linux.Statfs, error) { + return vfs.GenericStatFS(linux.PROC_SUPER_MAGIC), nil +} diff --git a/pkg/sentry/fsimpl/proc/subtasks.go b/pkg/sentry/fsimpl/proc/subtasks.go index 01c0efb3a..d57d94dbc 100644 --- a/pkg/sentry/fsimpl/proc/subtasks.go +++ b/pkg/sentry/fsimpl/proc/subtasks.go @@ -31,12 +31,13 @@ import ( // // +stateify savable type subtasksInode struct { - subtasksInodeRefs - kernfs.InodeNotSymlink - kernfs.InodeDirectoryNoNewChildren + implStatFS + kernfs.AlwaysValid kernfs.InodeAttrs + kernfs.InodeDirectoryNoNewChildren + kernfs.InodeNotSymlink kernfs.OrderedChildren - kernfs.AlwaysValid + subtasksInodeRefs locks vfs.FileLocks diff --git a/pkg/sentry/fsimpl/proc/task.go b/pkg/sentry/fsimpl/proc/task.go index 66b557abd..dbdb5d929 100644 --- a/pkg/sentry/fsimpl/proc/task.go +++ b/pkg/sentry/fsimpl/proc/task.go @@ -32,12 +32,13 @@ import ( // // +stateify savable type taskInode struct { - taskInodeRefs - kernfs.InodeNotSymlink + implStatFS + kernfs.InodeAttrs kernfs.InodeDirectoryNoNewChildren kernfs.InodeNoDynamicLookup - kernfs.InodeAttrs + kernfs.InodeNotSymlink kernfs.OrderedChildren + taskInodeRefs locks vfs.FileLocks diff --git a/pkg/sentry/fsimpl/proc/task_fds.go b/pkg/sentry/fsimpl/proc/task_fds.go index 0527b2de8..3f0d78461 100644 --- a/pkg/sentry/fsimpl/proc/task_fds.go +++ b/pkg/sentry/fsimpl/proc/task_fds.go @@ -100,13 +100,14 @@ func (i *fdDir) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, off // // +stateify savable type fdDirInode struct { + fdDir fdDirInodeRefs - kernfs.InodeNotSymlink - kernfs.InodeDirectoryNoNewChildren + implStatFS + kernfs.AlwaysValid kernfs.InodeAttrs + kernfs.InodeDirectoryNoNewChildren + kernfs.InodeNotSymlink kernfs.OrderedChildren - kernfs.AlwaysValid - fdDir } var _ kernfs.Inode = (*fdDirInode)(nil) @@ -185,6 +186,7 @@ func (i *fdDirInode) DecRef(context.Context) { // // +stateify savable type fdSymlink struct { + implStatFS kernfs.InodeAttrs kernfs.InodeNoopRefCount kernfs.InodeSymlink @@ -233,13 +235,14 @@ func (s *fdSymlink) Getlink(ctx context.Context, mnt *vfs.Mount) (vfs.VirtualDen // // +stateify savable type fdInfoDirInode struct { + fdDir fdInfoDirInodeRefs - kernfs.InodeNotSymlink - kernfs.InodeDirectoryNoNewChildren + implStatFS + kernfs.AlwaysValid kernfs.InodeAttrs + kernfs.InodeDirectoryNoNewChildren + kernfs.InodeNotSymlink kernfs.OrderedChildren - kernfs.AlwaysValid - fdDir } var _ kernfs.Inode = (*fdInfoDirInode)(nil) diff --git a/pkg/sentry/fsimpl/proc/task_files.go b/pkg/sentry/fsimpl/proc/task_files.go index 830b78949..356036b9b 100644 --- a/pkg/sentry/fsimpl/proc/task_files.go +++ b/pkg/sentry/fsimpl/proc/task_files.go @@ -648,6 +648,7 @@ func (o *oomScoreAdj) Write(ctx context.Context, src usermem.IOSequence, offset // // +stateify savable type exeSymlink struct { + implStatFS kernfs.InodeAttrs kernfs.InodeNoopRefCount kernfs.InodeSymlink @@ -832,6 +833,7 @@ func (s *namespaceSymlink) Getlink(ctx context.Context, mnt *vfs.Mount) (vfs.Vir // namespaceInode is a synthetic inode created to represent a namespace in // /proc/[pid]/ns/*. type namespaceInode struct { + implStatFS kernfs.InodeAttrs kernfs.InodeNoopRefCount kernfs.InodeNotDirectory diff --git a/pkg/sentry/fsimpl/proc/tasks.go b/pkg/sentry/fsimpl/proc/tasks.go index 863c4467e..3ea00ab87 100644 --- a/pkg/sentry/fsimpl/proc/tasks.go +++ b/pkg/sentry/fsimpl/proc/tasks.go @@ -37,12 +37,13 @@ const ( // // +stateify savable type tasksInode struct { - tasksInodeRefs - kernfs.InodeNotSymlink - kernfs.InodeDirectoryNoNewChildren + implStatFS + kernfs.AlwaysValid kernfs.InodeAttrs + kernfs.InodeDirectoryNoNewChildren + kernfs.InodeNotSymlink kernfs.OrderedChildren - kernfs.AlwaysValid + tasksInodeRefs locks vfs.FileLocks diff --git a/pkg/sentry/fsimpl/proc/tasks_files.go b/pkg/sentry/fsimpl/proc/tasks_files.go index 7d8983aa5..8c41729e4 100644 --- a/pkg/sentry/fsimpl/proc/tasks_files.go +++ b/pkg/sentry/fsimpl/proc/tasks_files.go @@ -32,6 +32,7 @@ import ( ) type selfSymlink struct { + implStatFS kernfs.InodeAttrs kernfs.InodeNoopRefCount kernfs.InodeSymlink @@ -74,6 +75,7 @@ func (*selfSymlink) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, } type threadSelfSymlink struct { + implStatFS kernfs.InodeAttrs kernfs.InodeNoopRefCount kernfs.InodeSymlink diff --git a/pkg/sentry/fsimpl/sockfs/sockfs.go b/pkg/sentry/fsimpl/sockfs/sockfs.go index c61818ff6..94a998568 100644 --- a/pkg/sentry/fsimpl/sockfs/sockfs.go +++ b/pkg/sentry/fsimpl/sockfs/sockfs.go @@ -81,10 +81,10 @@ func (fs *filesystem) PrependPath(ctx context.Context, vfsroot, vd vfs.VirtualDe // inode implements kernfs.Inode. type inode struct { - kernfs.InodeNotDirectory - kernfs.InodeNotSymlink kernfs.InodeAttrs kernfs.InodeNoopRefCount + kernfs.InodeNotDirectory + kernfs.InodeNotSymlink } // Open implements kernfs.Inode.Open. @@ -92,6 +92,11 @@ func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentr return nil, syserror.ENXIO } +// StatFS implements kernfs.Inode.StatFS. +func (i *inode) StatFS(ctx context.Context, fs *vfs.Filesystem) (linux.Statfs, error) { + return vfs.GenericStatFS(linux.SOCKFS_MAGIC), nil +} + // NewDentry constructs and returns a sockfs dentry. // // Preconditions: mnt.Filesystem() must have been returned by NewFilesystem(). diff --git a/pkg/sentry/fsimpl/sys/kcov.go b/pkg/sentry/fsimpl/sys/kcov.go index 92710d877..73f3d3309 100644 --- a/pkg/sentry/fsimpl/sys/kcov.go +++ b/pkg/sentry/fsimpl/sys/kcov.go @@ -39,8 +39,9 @@ func (fs *filesystem) newKcovFile(ctx context.Context, creds *auth.Credentials) type kcovInode struct { kernfs.InodeAttrs kernfs.InodeNoopRefCount - kernfs.InodeNotSymlink kernfs.InodeNotDirectory + kernfs.InodeNotSymlink + implStatFS } func (i *kcovInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go index ea30a4ec2..39952d2d0 100644 --- a/pkg/sentry/fsimpl/sys/sys.go +++ b/pkg/sentry/fsimpl/sys/sys.go @@ -163,9 +163,16 @@ func (d *dir) DecRef(context.Context) { d.dirRefs.DecRef(d.Destroy) } +// StatFS implements kernfs.Inode.StatFS. +func (d *dir) StatFS(ctx context.Context, fs *vfs.Filesystem) (linux.Statfs, error) { + return vfs.GenericStatFS(linux.SYSFS_MAGIC), nil +} + // cpuFile implements kernfs.Inode. type cpuFile struct { + implStatFS kernfs.DynamicBytesFile + maxCores uint } @@ -182,3 +189,10 @@ func (fs *filesystem) newCPUFile(creds *auth.Credentials, maxCores uint, mode li d.Init(c) return d } + +type implStatFS struct{} + +// StatFS implements kernfs.Inode.StatFS. +func (*implStatFS) StatFS(context.Context, *vfs.Filesystem) (linux.Statfs, error) { + return vfs.GenericStatFS(linux.SYSFS_MAGIC), nil +} diff --git a/pkg/sentry/vfs/filesystem_impl_util.go b/pkg/sentry/vfs/filesystem_impl_util.go index 465e610e0..2620cf975 100644 --- a/pkg/sentry/vfs/filesystem_impl_util.go +++ b/pkg/sentry/vfs/filesystem_impl_util.go @@ -16,6 +16,9 @@ package vfs import ( "strings" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/usermem" ) // GenericParseMountOptions parses a comma-separated list of options of the @@ -41,3 +44,13 @@ func GenericParseMountOptions(str string) map[string]string { } return m } + +// GenericStatFS returns a statfs struct filled with the common fields for a +// general filesystem. This is analogous to Linux's fs/libfs.cs:simple_statfs(). +func GenericStatFS(fsMagic uint64) linux.Statfs { + return linux.Statfs{ + Type: fsMagic, + BlockSize: usermem.PageSize, + NameLength: linux.NAME_MAX, + } +} diff --git a/test/syscalls/BUILD b/test/syscalls/BUILD index 65e8299c3..f949bc0e3 100644 --- a/test/syscalls/BUILD +++ b/test/syscalls/BUILD @@ -803,6 +803,7 @@ syscall_test( syscall_test( add_overlay = True, test = "//test/syscalls/linux:statfs_test", + use_tmpfs = True, # Test specifically relies on TEST_TMPDIR to be tmpfs. ) syscall_test( diff --git a/test/syscalls/linux/pipe.cc b/test/syscalls/linux/pipe.cc index 34291850d..c097c9187 100644 --- a/test/syscalls/linux/pipe.cc +++ b/test/syscalls/linux/pipe.cc @@ -13,7 +13,9 @@ // limitations under the License. #include /* Obtain O_* constant definitions */ +#include #include +#include #include #include @@ -198,6 +200,16 @@ TEST_P(PipeTest, NonBlocking) { SyscallFailsWithErrno(EWOULDBLOCK)); } +TEST(PipeTest, StatFS) { + int fds[2]; + ASSERT_THAT(pipe(fds), SyscallSucceeds()); + struct statfs st; + EXPECT_THAT(fstatfs(fds[0], &st), SyscallSucceeds()); + EXPECT_EQ(st.f_type, PIPEFS_MAGIC); + EXPECT_EQ(st.f_bsize, getpagesize()); + EXPECT_EQ(st.f_namelen, NAME_MAX); +} + TEST(Pipe2Test, CloExec) { int fds[2]; ASSERT_THAT(pipe2(fds, O_CLOEXEC), SyscallSucceeds()); diff --git a/test/syscalls/linux/proc.cc b/test/syscalls/linux/proc.cc index d6b875dbf..b73189e55 100644 --- a/test/syscalls/linux/proc.cc +++ b/test/syscalls/linux/proc.cc @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -26,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -2159,6 +2161,18 @@ TEST(Proc, PidTidIOAccounting) { noop.Join(); } +TEST(Proc, Statfs) { + struct statfs st; + EXPECT_THAT(statfs("/proc", &st), SyscallSucceeds()); + if (IsRunningWithVFS1()) { + EXPECT_EQ(st.f_type, ANON_INODE_FS_MAGIC); + } else { + EXPECT_EQ(st.f_type, PROC_SUPER_MAGIC); + } + EXPECT_EQ(st.f_bsize, getpagesize()); + EXPECT_EQ(st.f_namelen, NAME_MAX); +} + } // namespace } // namespace testing } // namespace gvisor diff --git a/test/syscalls/linux/socket.cc b/test/syscalls/linux/socket.cc index c20cd3fcc..e680d3dd7 100644 --- a/test/syscalls/linux/socket.cc +++ b/test/syscalls/linux/socket.cc @@ -14,6 +14,7 @@ #include #include +#include #include #include @@ -26,6 +27,9 @@ namespace gvisor { namespace testing { +// From linux/magic.h, but we can't depend on linux headers here. +#define SOCKFS_MAGIC 0x534F434B + TEST(SocketTest, UnixSocketPairProtocol) { int socks[2]; ASSERT_THAT(socketpair(AF_UNIX, SOCK_STREAM, PF_UNIX, socks), @@ -94,6 +98,19 @@ TEST(SocketTest, UnixSocketStat) { } } +TEST(SocketTest, UnixSocketStatFS) { + SKIP_IF(IsRunningWithVFS1()); + + FileDescriptor bound = + ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_UNIX, SOCK_STREAM, PF_UNIX)); + + struct statfs st; + EXPECT_THAT(fstatfs(bound.get(), &st), SyscallSucceeds()); + EXPECT_EQ(st.f_type, SOCKFS_MAGIC); + EXPECT_EQ(st.f_bsize, getpagesize()); + EXPECT_EQ(st.f_namelen, NAME_MAX); +} + using SocketOpenTest = ::testing::TestWithParam; // UDS cannot be opened. diff --git a/test/syscalls/linux/statfs.cc b/test/syscalls/linux/statfs.cc index aca51d30f..49f2f156c 100644 --- a/test/syscalls/linux/statfs.cc +++ b/test/syscalls/linux/statfs.cc @@ -13,6 +13,7 @@ // limitations under the License. #include +#include #include #include @@ -26,6 +27,10 @@ namespace testing { namespace { +// From linux/magic.h. For some reason, not defined in the headers for some +// build environments. +#define OVERLAYFS_SUPER_MAGIC 0x794c7630 + TEST(StatfsTest, CannotStatBadPath) { auto temp_file = NewTempAbsPathInDir("/tmp"); @@ -38,19 +43,18 @@ TEST(StatfsTest, InternalTmpfs) { struct statfs st; EXPECT_THAT(statfs(temp_file.path().c_str(), &st), SyscallSucceeds()); + // Note: We could be an overlay or goferfs on some configurations. + EXPECT_TRUE(st.f_type == TMPFS_MAGIC || st.f_type == OVERLAYFS_SUPER_MAGIC || + st.f_type == V9FS_MAGIC); } TEST(StatfsTest, InternalDevShm) { struct statfs st; EXPECT_THAT(statfs("/dev/shm", &st), SyscallSucceeds()); -} - -TEST(StatfsTest, NameLen) { - struct statfs st; - EXPECT_THAT(statfs("/dev/shm", &st), SyscallSucceeds()); // This assumes that /dev/shm is tmpfs. - EXPECT_EQ(st.f_namelen, NAME_MAX); + // Note: We could be an overlay on some configurations. + EXPECT_TRUE(st.f_type == TMPFS_MAGIC || st.f_type == OVERLAYFS_SUPER_MAGIC); } TEST(FstatfsTest, CannotStatBadFd) { -- cgit v1.2.3 From f2f92e52f6548b3b29d561d6d334a4f1fdbd8437 Mon Sep 17 00:00:00 2001 From: Fabricio Voznika Date: Tue, 8 Sep 2020 13:58:50 -0700 Subject: Honor readonly flag for root mount Updates #1487 PiperOrigin-RevId: 330580699 --- pkg/sentry/fsimpl/devtmpfs/devtmpfs.go | 2 +- pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go | 2 +- pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go | 6 +- pkg/sentry/fsimpl/ext/ext_test.go | 6 +- pkg/sentry/fsimpl/fuse/dev_test.go | 2 +- pkg/sentry/fsimpl/kernfs/kernfs_test.go | 2 +- pkg/sentry/fsimpl/proc/tasks_test.go | 2 +- pkg/sentry/fsimpl/sys/sys_test.go | 2 +- pkg/sentry/fsimpl/tmpfs/benchmark_test.go | 4 +- pkg/sentry/fsimpl/tmpfs/pipe_test.go | 2 +- pkg/sentry/fsimpl/tmpfs/tmpfs_test.go | 2 +- pkg/sentry/vfs/mount.go | 6 +- runsc/boot/fs.go | 8 +- runsc/boot/loader_test.go | 4 +- runsc/boot/vfs.go | 35 ++++- runsc/container/container_test.go | 180 +++++++++++++--------- runsc/container/multi_container_test.go | 21 +-- runsc/container/shared_volume_test.go | 12 +- 18 files changed, 178 insertions(+), 120 deletions(-) (limited to 'pkg/sentry/fsimpl/sys') diff --git a/pkg/sentry/fsimpl/devtmpfs/devtmpfs.go b/pkg/sentry/fsimpl/devtmpfs/devtmpfs.go index 52f44f66d..a23094e54 100644 --- a/pkg/sentry/fsimpl/devtmpfs/devtmpfs.go +++ b/pkg/sentry/fsimpl/devtmpfs/devtmpfs.go @@ -80,7 +80,7 @@ type Accessor struct { // NewAccessor returns an Accessor that supports creation of device special // files in the devtmpfs instance registered with name fsTypeName in vfsObj. func NewAccessor(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, fsTypeName string) (*Accessor, error) { - mntns, err := vfsObj.NewMountNamespace(ctx, creds, "devtmpfs" /* source */, fsTypeName, &vfs.GetFilesystemOptions{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "devtmpfs" /* source */, fsTypeName, &vfs.MountOptions{}) if err != nil { return nil, err } diff --git a/pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go b/pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go index 827a608cb..3a38b8bb4 100644 --- a/pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go +++ b/pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go @@ -48,7 +48,7 @@ func setupDevtmpfs(t *testing.T) (context.Context, *auth.Credentials, *vfs.Virtu }) // Create a test mount namespace with devtmpfs mounted at "/dev". - mntns, err := vfsObj.NewMountNamespace(ctx, creds, "tmpfs" /* source */, "tmpfs" /* fsTypeName */, &vfs.GetFilesystemOptions{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "tmpfs" /* source */, "tmpfs" /* fsTypeName */, &vfs.MountOptions{}) if err != nil { t.Fatalf("failed to create tmpfs root mount: %v", err) } diff --git a/pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go b/pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go index a2cc9b59f..c349b886e 100644 --- a/pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go +++ b/pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go @@ -59,7 +59,11 @@ func setUp(b *testing.B, imagePath string) (context.Context, *vfs.VirtualFilesys vfsObj.MustRegisterFilesystemType("extfs", ext.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mntns, err := vfsObj.NewMountNamespace(ctx, creds, imagePath, "extfs", &vfs.GetFilesystemOptions{InternalData: int(f.Fd())}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, imagePath, "extfs", &vfs.MountOptions{ + GetFilesystemOptions: vfs.GetFilesystemOptions{ + InternalData: int(f.Fd()), + }, + }) if err != nil { f.Close() return nil, nil, nil, nil, err diff --git a/pkg/sentry/fsimpl/ext/ext_test.go b/pkg/sentry/fsimpl/ext/ext_test.go index 2dbaee287..0989558cd 100644 --- a/pkg/sentry/fsimpl/ext/ext_test.go +++ b/pkg/sentry/fsimpl/ext/ext_test.go @@ -71,7 +71,11 @@ func setUp(t *testing.T, imagePath string) (context.Context, *vfs.VirtualFilesys vfsObj.MustRegisterFilesystemType("extfs", FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mntns, err := vfsObj.NewMountNamespace(ctx, creds, localImagePath, "extfs", &vfs.GetFilesystemOptions{InternalData: int(f.Fd())}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, localImagePath, "extfs", &vfs.MountOptions{ + GetFilesystemOptions: vfs.GetFilesystemOptions{ + InternalData: int(f.Fd()), + }, + }) if err != nil { f.Close() return nil, nil, nil, nil, err diff --git a/pkg/sentry/fsimpl/fuse/dev_test.go b/pkg/sentry/fsimpl/fuse/dev_test.go index 1ffe7ccd2..aedc2fa39 100644 --- a/pkg/sentry/fsimpl/fuse/dev_test.go +++ b/pkg/sentry/fsimpl/fuse/dev_test.go @@ -342,7 +342,7 @@ func setup(t *testing.T) *testutil.System { AllowUserMount: true, }) - mntns, err := k.VFS().NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{}) + mntns, err := k.VFS().NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.MountOptions{}) if err != nil { t.Fatalf("NewMountNamespace(): %v", err) } diff --git a/pkg/sentry/fsimpl/kernfs/kernfs_test.go b/pkg/sentry/fsimpl/kernfs/kernfs_test.go index 675587c6b..09806a3f2 100644 --- a/pkg/sentry/fsimpl/kernfs/kernfs_test.go +++ b/pkg/sentry/fsimpl/kernfs/kernfs_test.go @@ -52,7 +52,7 @@ func newTestSystem(t *testing.T, rootFn RootDentryFn) *testutil.System { v.MustRegisterFilesystemType("testfs", &fsType{rootFn: rootFn}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mns, err := v.NewMountNamespace(ctx, creds, "", "testfs", &vfs.GetFilesystemOptions{}) + mns, err := v.NewMountNamespace(ctx, creds, "", "testfs", &vfs.MountOptions{}) if err != nil { t.Fatalf("Failed to create testfs root mount: %v", err) } diff --git a/pkg/sentry/fsimpl/proc/tasks_test.go b/pkg/sentry/fsimpl/proc/tasks_test.go index d82b3d2f3..f693f9060 100644 --- a/pkg/sentry/fsimpl/proc/tasks_test.go +++ b/pkg/sentry/fsimpl/proc/tasks_test.go @@ -104,7 +104,7 @@ func setup(t *testing.T) *testutil.System { AllowUserMount: true, }) - mntns, err := k.VFS().NewMountNamespace(ctx, creds, "", tmpfs.Name, &vfs.GetFilesystemOptions{}) + mntns, err := k.VFS().NewMountNamespace(ctx, creds, "", tmpfs.Name, &vfs.MountOptions{}) if err != nil { t.Fatalf("NewMountNamespace(): %v", err) } diff --git a/pkg/sentry/fsimpl/sys/sys_test.go b/pkg/sentry/fsimpl/sys/sys_test.go index 9fd38b295..0a0d914cc 100644 --- a/pkg/sentry/fsimpl/sys/sys_test.go +++ b/pkg/sentry/fsimpl/sys/sys_test.go @@ -38,7 +38,7 @@ func newTestSystem(t *testing.T) *testutil.System { AllowUserMount: true, }) - mns, err := k.VFS().NewMountNamespace(ctx, creds, "", sys.Name, &vfs.GetFilesystemOptions{}) + mns, err := k.VFS().NewMountNamespace(ctx, creds, "", sys.Name, &vfs.MountOptions{}) if err != nil { t.Fatalf("Failed to create new mount namespace: %v", err) } diff --git a/pkg/sentry/fsimpl/tmpfs/benchmark_test.go b/pkg/sentry/fsimpl/tmpfs/benchmark_test.go index e5a4218e8..5209a17af 100644 --- a/pkg/sentry/fsimpl/tmpfs/benchmark_test.go +++ b/pkg/sentry/fsimpl/tmpfs/benchmark_test.go @@ -182,7 +182,7 @@ func BenchmarkVFS2TmpfsStat(b *testing.B) { vfsObj.MustRegisterFilesystemType("tmpfs", tmpfs.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.MountOptions{}) if err != nil { b.Fatalf("failed to create tmpfs root mount: %v", err) } @@ -376,7 +376,7 @@ func BenchmarkVFS2TmpfsMountStat(b *testing.B) { vfsObj.MustRegisterFilesystemType("tmpfs", tmpfs.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.MountOptions{}) if err != nil { b.Fatalf("failed to create tmpfs root mount: %v", err) } diff --git a/pkg/sentry/fsimpl/tmpfs/pipe_test.go b/pkg/sentry/fsimpl/tmpfs/pipe_test.go index ec2701d8b..be29a2363 100644 --- a/pkg/sentry/fsimpl/tmpfs/pipe_test.go +++ b/pkg/sentry/fsimpl/tmpfs/pipe_test.go @@ -158,7 +158,7 @@ func setup(t *testing.T) (context.Context, *auth.Credentials, *vfs.VirtualFilesy vfsObj.MustRegisterFilesystemType("tmpfs", FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.MountOptions{}) if err != nil { t.Fatalf("failed to create tmpfs root mount: %v", err) } diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs_test.go b/pkg/sentry/fsimpl/tmpfs/tmpfs_test.go index 6f3e3ae6f..99c8e3c0f 100644 --- a/pkg/sentry/fsimpl/tmpfs/tmpfs_test.go +++ b/pkg/sentry/fsimpl/tmpfs/tmpfs_test.go @@ -41,7 +41,7 @@ func newTmpfsRoot(ctx context.Context) (*vfs.VirtualFilesystem, vfs.VirtualDentr vfsObj.MustRegisterFilesystemType("tmpfs", FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserMount: true, }) - mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{}) + mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.MountOptions{}) if err != nil { return nil, vfs.VirtualDentry{}, nil, fmt.Errorf("failed to create tmpfs root mount: %v", err) } diff --git a/pkg/sentry/vfs/mount.go b/pkg/sentry/vfs/mount.go index db5fb3bb1..06ca91989 100644 --- a/pkg/sentry/vfs/mount.go +++ b/pkg/sentry/vfs/mount.go @@ -154,13 +154,13 @@ type MountNamespace struct { // NewMountNamespace returns a new mount namespace with a root filesystem // configured by the given arguments. A reference is taken on the returned // MountNamespace. -func (vfs *VirtualFilesystem) NewMountNamespace(ctx context.Context, creds *auth.Credentials, source, fsTypeName string, opts *GetFilesystemOptions) (*MountNamespace, error) { +func (vfs *VirtualFilesystem) NewMountNamespace(ctx context.Context, creds *auth.Credentials, source, fsTypeName string, opts *MountOptions) (*MountNamespace, error) { rft := vfs.getFilesystemType(fsTypeName) if rft == nil { ctx.Warningf("Unknown filesystem type: %s", fsTypeName) return nil, syserror.ENODEV } - fs, root, err := rft.fsType.GetFilesystem(ctx, vfs, creds, source, *opts) + fs, root, err := rft.fsType.GetFilesystem(ctx, vfs, creds, source, opts.GetFilesystemOptions) if err != nil { return nil, err } @@ -169,7 +169,7 @@ func (vfs *VirtualFilesystem) NewMountNamespace(ctx context.Context, creds *auth mountpoints: make(map[*Dentry]uint32), } mntns.EnableLeakCheck() - mntns.root = newMount(vfs, fs, root, mntns, &MountOptions{}) + mntns.root = newMount(vfs, fs, root, mntns, opts) return mntns, nil } diff --git a/runsc/boot/fs.go b/runsc/boot/fs.go index e2c5f5fb1..ddf288456 100644 --- a/runsc/boot/fs.go +++ b/runsc/boot/fs.go @@ -254,7 +254,7 @@ func mustFindFilesystem(name string) fs.Filesystem { // addSubmountOverlay overlays the inode over a ramfs tree containing the given // paths. -func addSubmountOverlay(ctx context.Context, inode *fs.Inode, submounts []string) (*fs.Inode, error) { +func addSubmountOverlay(ctx context.Context, inode *fs.Inode, submounts []string, mf fs.MountSourceFlags) (*fs.Inode, error) { // Construct a ramfs tree of mount points. The contents never // change, so this can be fully caching. There's no real // filesystem backing this tree, so we set the filesystem to @@ -264,7 +264,7 @@ func addSubmountOverlay(ctx context.Context, inode *fs.Inode, submounts []string if err != nil { return nil, fmt.Errorf("creating mount tree: %v", err) } - overlayInode, err := fs.NewOverlayRoot(ctx, inode, mountTree, fs.MountSourceFlags{}) + overlayInode, err := fs.NewOverlayRoot(ctx, inode, mountTree, mf) if err != nil { return nil, fmt.Errorf("adding mount overlay: %v", err) } @@ -741,7 +741,7 @@ func (c *containerMounter) createRootMount(ctx context.Context, conf *config.Con // for submount paths. "/dev" "/sys" "/proc" and "/tmp" are always // mounted even if they are not in the spec. submounts := append(subtargets("/", c.mounts), "/dev", "/sys", "/proc", "/tmp") - rootInode, err = addSubmountOverlay(ctx, rootInode, submounts) + rootInode, err = addSubmountOverlay(ctx, rootInode, submounts, mf) if err != nil { return nil, fmt.Errorf("adding submount overlay: %v", err) } @@ -851,7 +851,7 @@ func (c *containerMounter) mountSubmount(ctx context.Context, conf *config.Confi submounts := subtargets(m.Destination, c.mounts) if len(submounts) > 0 { log.Infof("Adding submount overlay over %q", m.Destination) - inode, err = addSubmountOverlay(ctx, inode, submounts) + inode, err = addSubmountOverlay(ctx, inode, submounts, mf) if err != nil { return fmt.Errorf("adding submount overlay: %v", err) } diff --git a/runsc/boot/loader_test.go b/runsc/boot/loader_test.go index dc9861389..bf9ec5d38 100644 --- a/runsc/boot/loader_test.go +++ b/runsc/boot/loader_test.go @@ -491,9 +491,9 @@ func TestCreateMountNamespaceVFS2(t *testing.T) { } ctx := l.k.SupervisorContext() - mns, err := mntr.setupVFS2(ctx, l.root.conf, &l.root.procArgs) + mns, err := mntr.mountAll(l.root.conf, &l.root.procArgs) if err != nil { - t.Fatalf("failed to setupVFS2: %v", err) + t.Fatalf("mountAll: %v", err) } root := mns.Root() diff --git a/runsc/boot/vfs.go b/runsc/boot/vfs.go index 66b6cf19b..7844ea28c 100644 --- a/runsc/boot/vfs.go +++ b/runsc/boot/vfs.go @@ -134,7 +134,7 @@ func registerFilesystems(k *kernel.Kernel) error { } func setupContainerVFS2(ctx context.Context, conf *config.Config, mntr *containerMounter, procArgs *kernel.CreateProcessArgs) error { - mns, err := mntr.setupVFS2(ctx, conf, procArgs) + mns, err := mntr.mountAll(conf, procArgs) if err != nil { return fmt.Errorf("failed to setupFS: %w", err) } @@ -149,7 +149,7 @@ func setupContainerVFS2(ctx context.Context, conf *config.Config, mntr *containe return nil } -func (c *containerMounter) setupVFS2(ctx context.Context, conf *config.Config, procArgs *kernel.CreateProcessArgs) (*vfs.MountNamespace, error) { +func (c *containerMounter) mountAll(conf *config.Config, procArgs *kernel.CreateProcessArgs) (*vfs.MountNamespace, error) { log.Infof("Configuring container's file system with VFS2") // Create context with root credentials to mount the filesystem (the current @@ -172,24 +172,44 @@ func (c *containerMounter) setupVFS2(ctx context.Context, conf *config.Config, p if err := c.mountSubmountsVFS2(rootCtx, conf, mns, rootCreds); err != nil { return nil, fmt.Errorf("mounting submounts vfs2: %w", err) } + + if c.root.Readonly || conf.Overlay { + // Switch to ReadOnly after all submounts were setup. + root := mns.Root() + defer root.DecRef(rootCtx) + if err := c.k.VFS().SetMountReadOnly(root.Mount(), true); err != nil { + return nil, fmt.Errorf(`failed to set mount at "/" readonly: %v`, err) + } + } + return mns, nil } +// createMountNamespaceVFS2 creates the container's root mount and namespace. +// The mount is created ReadWrite to allow mount point for submounts to be +// created. ** The caller is responsible to switch to ReadOnly if needed ** func (c *containerMounter) createMountNamespaceVFS2(ctx context.Context, conf *config.Config, creds *auth.Credentials) (*vfs.MountNamespace, error) { fd := c.fds.remove() - opts := p9MountData(fd, conf.FileAccess, true /* vfs2 */) + data := p9MountData(fd, conf.FileAccess, true /* vfs2 */) if conf.OverlayfsStaleRead { // We can't check for overlayfs here because sandbox is chroot'ed and gofer // can only send mount options for specs.Mounts (specs.Root is missing // Options field). So assume root is always on top of overlayfs. - opts = append(opts, "overlayfs_stale_read") + data = append(data, "overlayfs_stale_read") } log.Infof("Mounting root over 9P, ioFD: %d", fd) - mns, err := c.k.VFS().NewMountNamespace(ctx, creds, "", gofer.Name, &vfs.GetFilesystemOptions{ - Data: strings.Join(opts, ","), - }) + opts := &vfs.MountOptions{ + // Always mount as ReadWrite to allow other mounts on top of it. It'll be + // made ReadOnly in the caller (if needed). + ReadOnly: false, + GetFilesystemOptions: vfs.GetFilesystemOptions{ + Data: strings.Join(data, ","), + }, + InternalMount: true, + } + mns, err := c.k.VFS().NewMountNamespace(ctx, creds, "", gofer.Name, opts) if err != nil { return nil, fmt.Errorf("setting up mount namespace: %w", err) } @@ -227,6 +247,7 @@ func (c *containerMounter) mountSubmountsVFS2(ctx context.Context, conf *config. if err := c.k.VFS().SetMountReadOnly(mnt, false); err != nil { return fmt.Errorf("failed to set mount at %q readwrite: %v", submount.Destination, err) } + // Restore back to ReadOnly at the end. defer func() { if err := c.k.VFS().SetMountReadOnly(mnt, true); err != nil { panic(fmt.Sprintf("failed to restore mount at %q back to readonly: %v", submount.Destination, err)) diff --git a/runsc/container/container_test.go b/runsc/container/container_test.go index 6082068c7..33ada5bb9 100644 --- a/runsc/container/container_test.go +++ b/runsc/container/container_test.go @@ -41,6 +41,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/test/testutil" + "gvisor.dev/gvisor/pkg/urpc" "gvisor.dev/gvisor/runsc/boot/platforms" "gvisor.dev/gvisor/runsc/config" "gvisor.dev/gvisor/runsc/specutils" @@ -1490,6 +1491,8 @@ func TestMountNewDir(t *testing.T) { Source: srcDir, Type: "bind", }) + // Extra points for creating the mount with a readonly root. + spec.Root.Readonly = true if err := run(spec, conf); err != nil { t.Fatalf("error running sandbox: %v", err) @@ -1499,17 +1502,17 @@ func TestMountNewDir(t *testing.T) { } func TestReadonlyRoot(t *testing.T) { - for name, conf := range configsWithVFS2(t, overlay) { + for name, conf := range configsWithVFS2(t, all...) { t.Run(name, func(t *testing.T) { - spec := testutil.NewSpecWithArgs("/bin/touch", "/foo") + spec := testutil.NewSpecWithArgs("sleep", "100") spec.Root.Readonly = true + _, bundleDir, cleanup, err := testutil.SetupContainer(spec, conf) if err != nil { t.Fatalf("error setting up container: %v", err) } defer cleanup() - // Create, start and wait for the container. args := Args{ ID: testutil.RandomContainerID(), Spec: spec, @@ -1524,12 +1527,82 @@ func TestReadonlyRoot(t *testing.T) { t.Fatalf("error starting container: %v", err) } - ws, err := c.Wait() + // Read mounts to check that root is readonly. + out, ws, err := executeCombinedOutput(c, "/bin/sh", "-c", "mount | grep ' / '") + if err != nil || ws != 0 { + t.Fatalf("exec failed, ws: %v, err: %v", ws, err) + } + t.Logf("root mount: %q", out) + if !strings.Contains(string(out), "(ro)") { + t.Errorf("root not mounted readonly: %q", out) + } + + // Check that file cannot be created. + ws, err = execute(c, "/bin/touch", "/foo") if err != nil { - t.Fatalf("error waiting on container: %v", err) + t.Fatalf("touch file in ro mount: %v", err) } if !ws.Exited() || syscall.Errno(ws.ExitStatus()) != syscall.EPERM { - t.Fatalf("container failed, waitStatus: %v", ws) + t.Fatalf("wrong waitStatus: %v", ws) + } + }) + } +} + +func TestReadonlyMount(t *testing.T) { + for name, conf := range configsWithVFS2(t, all...) { + t.Run(name, func(t *testing.T) { + dir, err := ioutil.TempDir(testutil.TmpDir(), "ro-mount") + if err != nil { + t.Fatalf("ioutil.TempDir() failed: %v", err) + } + spec := testutil.NewSpecWithArgs("sleep", "100") + spec.Mounts = append(spec.Mounts, specs.Mount{ + Destination: dir, + Source: dir, + Type: "bind", + Options: []string{"ro"}, + }) + spec.Root.Readonly = false + + _, bundleDir, cleanup, err := testutil.SetupContainer(spec, conf) + if err != nil { + t.Fatalf("error setting up container: %v", err) + } + defer cleanup() + + args := Args{ + ID: testutil.RandomContainerID(), + Spec: spec, + BundleDir: bundleDir, + } + c, err := New(conf, args) + if err != nil { + t.Fatalf("error creating container: %v", err) + } + defer c.Destroy() + if err := c.Start(conf); err != nil { + t.Fatalf("error starting container: %v", err) + } + + // Read mounts to check that volume is readonly. + cmd := fmt.Sprintf("mount | grep ' %s '", dir) + out, ws, err := executeCombinedOutput(c, "/bin/sh", "-c", cmd) + if err != nil || ws != 0 { + t.Fatalf("exec failed, ws: %v, err: %v", ws, err) + } + t.Logf("mount: %q", out) + if !strings.Contains(string(out), "(ro)") { + t.Errorf("volume not mounted readonly: %q", out) + } + + // Check that file cannot be created. + ws, err = execute(c, "/bin/touch", path.Join(dir, "file")) + if err != nil { + t.Fatalf("touch file in ro mount: %v", err) + } + if !ws.Exited() || syscall.Errno(ws.ExitStatus()) != syscall.EPERM { + t.Fatalf("wrong WaitStatus: %v", ws) } }) } @@ -1616,54 +1689,6 @@ func TestUIDMap(t *testing.T) { } } -func TestReadonlyMount(t *testing.T) { - for name, conf := range configsWithVFS2(t, overlay) { - t.Run(name, func(t *testing.T) { - dir, err := ioutil.TempDir(testutil.TmpDir(), "ro-mount") - spec := testutil.NewSpecWithArgs("/bin/touch", path.Join(dir, "file")) - if err != nil { - t.Fatalf("ioutil.TempDir() failed: %v", err) - } - spec.Mounts = append(spec.Mounts, specs.Mount{ - Destination: dir, - Source: dir, - Type: "bind", - Options: []string{"ro"}, - }) - spec.Root.Readonly = false - - _, bundleDir, cleanup, err := testutil.SetupContainer(spec, conf) - if err != nil { - t.Fatalf("error setting up container: %v", err) - } - defer cleanup() - - // Create, start and wait for the container. - args := Args{ - ID: testutil.RandomContainerID(), - Spec: spec, - BundleDir: bundleDir, - } - c, err := New(conf, args) - if err != nil { - t.Fatalf("error creating container: %v", err) - } - defer c.Destroy() - if err := c.Start(conf); err != nil { - t.Fatalf("error starting container: %v", err) - } - - ws, err := c.Wait() - if err != nil { - t.Fatalf("error waiting on container: %v", err) - } - if !ws.Exited() || syscall.Errno(ws.ExitStatus()) != syscall.EPERM { - t.Fatalf("container failed, waitStatus: %v", ws) - } - }) - } -} - // TestAbbreviatedIDs checks that runsc supports using abbreviated container // IDs in place of full IDs. func TestAbbreviatedIDs(t *testing.T) { @@ -2116,21 +2141,13 @@ func TestMountPropagation(t *testing.T) { // Check that mount didn't propagate to private mount. privFile := filepath.Join(priv, "mnt", "file") - execArgs := &control.ExecArgs{ - Filename: "/usr/bin/test", - Argv: []string{"test", "!", "-f", privFile}, - } - if ws, err := cont.executeSync(execArgs); err != nil || ws != 0 { + if ws, err := execute(cont, "/usr/bin/test", "!", "-f", privFile); err != nil || ws != 0 { t.Fatalf("exec: test ! -f %q, ws: %v, err: %v", privFile, ws, err) } // Check that mount propagated to slave mount. slaveFile := filepath.Join(slave, "mnt", "file") - execArgs = &control.ExecArgs{ - Filename: "/usr/bin/test", - Argv: []string{"test", "-f", slaveFile}, - } - if ws, err := cont.executeSync(execArgs); err != nil || ws != 0 { + if ws, err := execute(cont, "/usr/bin/test", "-f", slaveFile); err != nil || ws != 0 { t.Fatalf("exec: test -f %q, ws: %v, err: %v", privFile, ws, err) } } @@ -2196,11 +2213,7 @@ func TestMountSymlink(t *testing.T) { // Check that symlink was resolved and mount was created where the symlink // is pointing to. file := path.Join(target, "file") - execArgs := &control.ExecArgs{ - Filename: "/usr/bin/test", - Argv: []string{"test", "-f", file}, - } - if ws, err := cont.executeSync(execArgs); err != nil || ws != 0 { + if ws, err := execute(cont, "/usr/bin/test", "-f", file); err != nil || ws != 0 { t.Fatalf("exec: test -f %q, ws: %v, err: %v", file, ws, err) } }) @@ -2326,6 +2339,35 @@ func TestTTYField(t *testing.T) { } } +func execute(cont *Container, name string, arg ...string) (syscall.WaitStatus, error) { + args := &control.ExecArgs{ + Filename: name, + Argv: append([]string{name}, arg...), + } + return cont.executeSync(args) +} + +func executeCombinedOutput(cont *Container, name string, arg ...string) ([]byte, syscall.WaitStatus, error) { + r, w, err := os.Pipe() + if err != nil { + return nil, 0, err + } + defer r.Close() + + args := &control.ExecArgs{ + Filename: name, + Argv: append([]string{name}, arg...), + FilePayload: urpc.FilePayload{Files: []*os.File{os.Stdin, w, w}}, + } + ws, err := cont.executeSync(args) + w.Close() + if err != nil { + return nil, 0, err + } + out, err := ioutil.ReadAll(r) + return out, ws, err +} + // executeSync synchronously executes a new process. func (cont *Container) executeSync(args *control.ExecArgs) (syscall.WaitStatus, error) { pid, err := cont.Execute(args) diff --git a/runsc/container/multi_container_test.go b/runsc/container/multi_container_test.go index 5b790c6c8..952215ec1 100644 --- a/runsc/container/multi_container_test.go +++ b/runsc/container/multi_container_test.go @@ -1517,8 +1517,7 @@ func TestMultiContainerGoferKilled(t *testing.T) { } // Check that container isn't running anymore. - args := &control.ExecArgs{Argv: []string{"/bin/true"}} - if _, err := c.executeSync(args); err == nil { + if _, err := execute(c, "/bin/true"); err == nil { t.Fatalf("Container %q was not stopped after gofer death", c.ID) } @@ -1533,8 +1532,7 @@ func TestMultiContainerGoferKilled(t *testing.T) { if err := waitForProcessList(c, pl); err != nil { t.Errorf("Container %q was affected by another container: %v", c.ID, err) } - args := &control.ExecArgs{Argv: []string{"/bin/true"}} - if _, err := c.executeSync(args); err != nil { + if _, err := execute(c, "/bin/true"); err != nil { t.Fatalf("Container %q was affected by another container: %v", c.ID, err) } } @@ -1556,8 +1554,7 @@ func TestMultiContainerGoferKilled(t *testing.T) { // Check that entire sandbox isn't running anymore. for _, c := range containers { - args := &control.ExecArgs{Argv: []string{"/bin/true"}} - if _, err := c.executeSync(args); err == nil { + if _, err := execute(c, "/bin/true"); err == nil { t.Fatalf("Container %q was not stopped after gofer death", c.ID) } } @@ -1719,12 +1716,11 @@ func TestMultiContainerHomeEnvDir(t *testing.T) { homeDirs[name] = homeFile } - // We will sleep in the root container in order to ensure that - // the root container doesn't terminate before sub containers can be - // created. + // We will sleep in the root container in order to ensure that the root + //container doesn't terminate before sub containers can be created. rootCmd := []string{"/bin/sh", "-c", fmt.Sprintf("printf \"$HOME\" > %s; sleep 1000", homeDirs["root"].Name())} subCmd := []string{"/bin/sh", "-c", fmt.Sprintf("printf \"$HOME\" > %s", homeDirs["sub"].Name())} - execCmd := []string{"/bin/sh", "-c", fmt.Sprintf("printf \"$HOME\" > %s", homeDirs["exec"].Name())} + execCmd := fmt.Sprintf("printf \"$HOME\" > %s", homeDirs["exec"].Name()) // Setup the containers, a root container and sub container. specConfig, ids := createSpecs(rootCmd, subCmd) @@ -1735,9 +1731,8 @@ func TestMultiContainerHomeEnvDir(t *testing.T) { defer cleanup() // Exec into the root container synchronously. - args := &control.ExecArgs{Argv: execCmd} - if _, err := containers[0].executeSync(args); err != nil { - t.Errorf("error executing %+v: %v", args, err) + if _, err := execute(containers[0], "/bin/sh", "-c", execCmd); err != nil { + t.Errorf("error executing %+v: %v", execCmd, err) } // Wait for the subcontainer to finish. diff --git a/runsc/container/shared_volume_test.go b/runsc/container/shared_volume_test.go index 4ea8fefee..cb5bffb89 100644 --- a/runsc/container/shared_volume_test.go +++ b/runsc/container/shared_volume_test.go @@ -168,11 +168,7 @@ func TestSharedVolume(t *testing.T) { func checkFile(c *Container, filename string, want []byte) error { cpy := filename + ".copy" - argsCp := &control.ExecArgs{ - Filename: "/bin/cp", - Argv: []string{"cp", "-f", filename, cpy}, - } - if _, err := c.executeSync(argsCp); err != nil { + if _, err := execute(c, "/bin/cp", "-f", filename, cpy); err != nil { return fmt.Errorf("unexpected error copying file %q to %q: %v", filename, cpy, err) } got, err := ioutil.ReadFile(cpy) @@ -235,11 +231,7 @@ func TestSharedVolumeFile(t *testing.T) { } // Append to file inside the container and check that content is not lost. - argsAppend := &control.ExecArgs{ - Filename: "/bin/bash", - Argv: []string{"bash", "-c", "echo -n sandbox- >> " + filename}, - } - if _, err := c.executeSync(argsAppend); err != nil { + if _, err := execute(c, "/bin/bash", "-c", "echo -n sandbox- >> "+filename); err != nil { t.Fatalf("unexpected error appending file %q: %v", filename, err) } want = []byte("host-sandbox-") -- cgit v1.2.3