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2021-07-01Mix checklocks and atomic analyzers.Adin Scannell
This change makes the checklocks analyzer considerable more powerful, adding: * The ability to traverse complex structures, e.g. to have multiple nested fields as part of the annotation. * The ability to resolve simple anonymous functions and closures, and perform lock analysis across these invocations. This does not apply to closures that are passed elsewhere, since it is not possible to know the context in which they might be invoked. * The ability to annotate return values in addition to receivers and other parameters, with the same complex structures noted above. * Ignoring locking semantics for "fresh" objects, i.e. objects that are allocated in the local frame (typically a new-style function). * Sanity checking of locking state across block transitions and returns, to ensure that no unexpected locks are held. Note that initially, most of these findings are excluded by a comprehensive nogo.yaml. The findings that are included are fundamental lock violations. The changes here should be relatively low risk, minor refactorings to either include necessary annotations to simplify the code structure (in general removing closures in favor of methods) so that the analyzer can be easily track the lock state. This change additional includes two changes to nogo itself: * Sanity checking of all types to ensure that the binary and ast-derived types have a consistent objectpath, to prevent the bug above from occurring silently (and causing much confusion). This also requires a trick in order to ensure that serialized facts are consumable downstream. This can be removed with https://go-review.googlesource.com/c/tools/+/331789 merged. * A minor refactoring to isolation the objdump settings in its own package. This was originally used to implement the sanity check above, but this information is now being passed another way. The minor refactor is preserved however, since it cleans up the code slightly and is minimal risk. PiperOrigin-RevId: 382613300
2021-07-01[syserror] Update several syserror errors to linuxerr equivalents.Zach Koopmans
Update/remove most syserror errors to linuxerr equivalents. For list of removed errors, see //pkg/syserror/syserror.go. PiperOrigin-RevId: 382574582
2021-06-30[syserror] Update syserror to linuxerr for EACCES, EBADF, and EPERM.Zach Koopmans
Update all instances of the above errors to the faster linuxerr implementation. With the temporary linuxerr.Equals(), no logical changes are made. PiperOrigin-RevId: 382306655
2021-06-29[syserror] Change syserror to linuxerr for E2BIG, EADDRINUSE, and EINVALZach Koopmans
Remove three syserror entries duplicated in linuxerr. Because of the linuxerr.Equals method, this is a mere change of return values from syserror to linuxerr definitions. Done with only these three errnos as CLs removing all grow to a significantly large size. PiperOrigin-RevId: 382173835
2021-06-22[syserror] Add conversions to linuxerr with temporary Equals method.Zach Koopmans
Add Equals method to compare syserror and unix.Errno errors to linuxerr errors. This will facilitate removal of syserror definitions in a followup, and finding needed conversions from unix.Errno to linuxerr. PiperOrigin-RevId: 380909667
2021-06-10Minor VFS2 xattr changes.Jamie Liu
- Allow the gofer client to use most xattr namespaces. As documented by the updated comment, this is consistent with e.g. Linux's FUSE client, and allows gofers to provide extended attributes from FUSE filesystems. - Make tmpfs' listxattr omit xattrs in the "trusted" namespace for non-privileged users. PiperOrigin-RevId: 378778854
2021-06-01vfs: Don't allow to mount anything on top of detached mountsAndrei Vagin
PiperOrigin-RevId: 376932659
2021-05-14Resolve remaining O_PATH TODOs.Dean Deng
O_PATH is now implemented in vfs2. Fixes #2782. PiperOrigin-RevId: 373861410
2021-04-29Remove ResolvingPath.RestartFabricio Voznika
PiperOrigin-RevId: 371163405
2021-04-28Automated rollback of changelist 369686285Fabricio Voznika
PiperOrigin-RevId: 371015541
2021-04-22Also report mount options through /proc/<pid>/mounts.Rahat Mahmood
PiperOrigin-RevId: 369967629
2021-04-21Automated rollback of changelist 369325957Michael Pratt
PiperOrigin-RevId: 369686285
2021-04-19Add MultiGetAttr message to 9PFabricio Voznika
While using remote-validation, the vast majority of time spent during FS operations is re-walking the path to check for modifications and then closing the file given that in most cases it has not been modified externally. This change introduces a new 9P message called MultiGetAttr which bulks query attributes of several files in one shot. The returned attributes are then used to update cached dentries before they are walked. File attributes are updated for files that still exist. Dentries that have been deleted are removed from the cache. And negative cache entries are removed if a new file/directory was created externally. Similarly, synthetic dentries are replaced if a file/directory is created externally. The bulk update needs to be carefull not to follow symlinks, cross mount points, because the gofer doesn't know how to resolve symlinks and where mounts points are located. It also doesn't walk to the parent ("..") to avoid deadlocks. Here are the results: Workload VFS1 VFS2 Change bazel action 115s 70s 28.8s Stat/100 11,043us 7,623us 974us Updates #1638 PiperOrigin-RevId: 369325957
2021-04-02Implement cgroupfs.Rahat Mahmood
A skeleton implementation of cgroupfs. It supports trivial cpu and memory controllers with no support for hierarchies. PiperOrigin-RevId: 366561126
2021-03-29[syserror] Split usermem packageZach Koopmans
Split usermem package to help remove syserror dependency in go_marshal. New hostarch package contains code not dependent on syserror. PiperOrigin-RevId: 365651233
2021-03-24Add POLLRDNORM/POLLWRNORM support.Bhasker Hariharan
On Linux these are meant to be equivalent to POLLIN/POLLOUT. Rather than hack these on in sys_poll etc it felt cleaner to just cleanup the call sites to notify for both events. This is what linux does as well. Fixes #5544 PiperOrigin-RevId: 364859977
2021-03-11Report filesystem-specific mount options.Rahat Mahmood
PiperOrigin-RevId: 362406813
2021-03-03Add checklocks analyzer.Bhasker Hariharan
This validates that struct fields if annotated with "// checklocks:mu" where "mu" is a mutex field in the same struct then access to the field is only done with "mu" locked. All types that are guarded by a mutex must be annotated with // +checklocks:<mutex field name> For more details please refer to README.md. PiperOrigin-RevId: 360729328
2021-02-19Don't hold baseEndpoint.mu while calling EventUpdate().Nicolas Lacasse
This removes a three-lock deadlock between fdnotifier.notifier.mu, epoll.EventPoll.listsMu, and baseEndpoint.mu. A lock order comment was added to epoll/epoll.go. Also fix unsafe access of baseEndpoint.connected/receiver. PiperOrigin-RevId: 358515191
2021-02-17Add gohacks.Slice/StringHeader.Jamie Liu
See https://github.com/golang/go/issues/19367 for rationale. Note that the upstream decision arrived at in that thread, while useful for some of our use cases, doesn't account for all of our SliceHeader use cases (we often use SliceHeader to extract pointers from slices in a way that avoids bounds checking and/or handles nil slices correctly) and also doesn't exist yet. PiperOrigin-RevId: 358071574
2021-02-11Internal change.gVisor bot
PiperOrigin-RevId: 357090170
2021-02-10Support setgid directories in tmpfs and kernfsKevin Krakauer
PiperOrigin-RevId: 356868412
2021-02-10Don't allow to umount the namespace root mountAndrei Vagin
Linux does the same thing. Reported-by: syzbot+6c79385c930c929d1d9e@syzkaller.appspotmail.com PiperOrigin-RevId: 356854562
2021-02-09Add cleanup TODO for integer-based proc files.Dean Deng
PiperOrigin-RevId: 356645022
2021-02-03[vfs] Make sticky bit check consistent with Linux.Ayush Ranjan
Our implementation of vfs.CheckDeleteSticky was not consistent with Linux, specifically not consistent with fs/linux.h:check_sticky(). One of the biggest differences was that the vfs implementation did not allow the owner of the sticky directory to delete files inside it that belonged to other users. This change makes our implementation consistent with Linux. Also adds an integration test to check for this. This bug is also present in VFS1. Updates #3027 PiperOrigin-RevId: 355557425
2021-01-28Add O_PATH support in vfs2gVisor bot
PiperOrigin-RevId: 354367665
2021-01-26Move inotify events from syscall to vfs layer.Dean Deng
This also causes inotify events to be generated when reading files for exec. This change also requires us to adjust splice+inotify tests due to discrepancies between gVisor and Linux behavior. Note that these discrepancies existed before; we just did not exercise them previously. See comment for more details. Fixes #5348. PiperOrigin-RevId: 353907187
2021-01-26Do not generate extraneous IN_CLOSE inotify events.Dean Deng
IN_CLOSE should only be generated when a file description loses its last reference; not when a file descriptor is closed. See fs/file_table.c:__fput. Updates #5348. PiperOrigin-RevId: 353810697
2021-01-22Implement F_GETLK fcntl.Dean Deng
Fixes #5113. PiperOrigin-RevId: 353313374
2021-01-20Move Lock/UnlockPOSIX into LockFD util.Dean Deng
PiperOrigin-RevId: 352904728
2021-01-12Fix simple mistakes identified by goreportcard.Adin Scannell
These are primarily simplification and lint mistakes. However, minor fixes are also included and tests added where appropriate. PiperOrigin-RevId: 351425971
2020-12-09Add //pkg/sync:generic_atomicptrmap.Jamie Liu
AtomicPtrMap is a generic concurrent map from arbitrary keys to arbitrary pointer values. Benchmarks: name time/op StoreDelete/RWMutexMap-12 335ns ± 1% StoreDelete/SyncMap-12 705ns ± 3% StoreDelete/AtomicPtrMap-12 287ns ± 4% StoreDelete/AtomicPtrMapSharded-12 289ns ± 1% LoadOrStoreDelete/RWMutexMap-12 342ns ± 2% LoadOrStoreDelete/SyncMap-12 662ns ± 2% LoadOrStoreDelete/AtomicPtrMap-12 290ns ± 7% LoadOrStoreDelete/AtomicPtrMapSharded-12 293ns ± 2% LookupPositive/RWMutexMap-12 101ns ±26% LookupPositive/SyncMap-12 202ns ± 2% LookupPositive/AtomicPtrMap-12 71.1ns ± 2% LookupPositive/AtomicPtrMapSharded-12 73.2ns ± 1% LookupNegative/RWMutexMap-12 119ns ± 1% LookupNegative/SyncMap-12 154ns ± 1% LookupNegative/AtomicPtrMap-12 84.7ns ± 3% LookupNegative/AtomicPtrMapSharded-12 86.8ns ± 1% Concurrent/FixedKeys_1PercentWrites_RWMutexMap-12 1.32µs ± 2% Concurrent/FixedKeys_1PercentWrites_SyncMap-12 52.7ns ±10% Concurrent/FixedKeys_1PercentWrites_AtomicPtrMap-12 31.8ns ±20% Concurrent/FixedKeys_1PercentWrites_AtomicPtrMapSharded-12 24.0ns ±15% Concurrent/FixedKeys_10PercentWrites_RWMutexMap-12 860ns ± 3% Concurrent/FixedKeys_10PercentWrites_SyncMap-12 68.8ns ±20% Concurrent/FixedKeys_10PercentWrites_AtomicPtrMap-12 98.6ns ± 7% Concurrent/FixedKeys_10PercentWrites_AtomicPtrMapSharded-12 42.0ns ±25% Concurrent/FixedKeys_50PercentWrites_RWMutexMap-12 1.17µs ± 3% Concurrent/FixedKeys_50PercentWrites_SyncMap-12 136ns ±34% Concurrent/FixedKeys_50PercentWrites_AtomicPtrMap-12 286ns ± 3% Concurrent/FixedKeys_50PercentWrites_AtomicPtrMapSharded-12 115ns ±35% Concurrent/ChangingKeys_1PercentWrites_RWMutexMap-12 1.27µs ± 2% Concurrent/ChangingKeys_1PercentWrites_SyncMap-12 5.01µs ± 3% Concurrent/ChangingKeys_1PercentWrites_AtomicPtrMap-12 38.1ns ± 3% Concurrent/ChangingKeys_1PercentWrites_AtomicPtrMapSharded-12 22.6ns ± 2% Concurrent/ChangingKeys_10PercentWrites_RWMutexMap-12 1.08µs ± 2% Concurrent/ChangingKeys_10PercentWrites_SyncMap-12 5.97µs ± 1% Concurrent/ChangingKeys_10PercentWrites_AtomicPtrMap-12 390ns ± 2% Concurrent/ChangingKeys_10PercentWrites_AtomicPtrMapSharded-12 93.6ns ± 1% Concurrent/ChangingKeys_50PercentWrites_RWMutexMap-12 1.77µs ± 2% Concurrent/ChangingKeys_50PercentWrites_SyncMap-12 8.07µs ± 2% Concurrent/ChangingKeys_50PercentWrites_AtomicPtrMap-12 1.61µs ± 2% Concurrent/ChangingKeys_50PercentWrites_AtomicPtrMapSharded-12 386ns ± 1% Updates #231 PiperOrigin-RevId: 346614776
2020-12-04Overlay runsc regular file mounts with regular files.Jamie Liu
Fixes #4991 PiperOrigin-RevId: 345800333
2020-12-03Implement `fcntl` options `F_GETSIG` and `F_SETSIG`.Etienne Perot
These options allow overriding the signal that gets sent to the process when I/O operations are available on the file descriptor, rather than the default `SIGIO` signal. Doing so also populates `siginfo` to contain extra information about which file descriptor caused the event (`si_fd`) and what events happened on it (`si_band`). The logic around which FD is populated within `si_fd` matches Linux's, which means it has some weird edge cases where that value may not actually refer to a file descriptor that is still valid. This CL also ports extra S/R logic regarding async handler in VFS2. Without this, async I/O handlers aren't properly re-registered after S/R. PiperOrigin-RevId: 345436598
2020-12-02Remove FileReadWriteSeeker from vfs.Jamie Liu
Previous experience has shown that these types of wrappers tends to create two kinds of problems: hidden allocations (e.g. each call to FileReadWriteSeeker.Read/Write allocates a usermem.BytesIO on the heap) and hidden lock ordering problems (e.g. VFS1 splice deadlocks). Since this is only needed by fsimpl/verity, move it there. PiperOrigin-RevId: 345377830
2020-11-18Port filesystem metrics to VFS2.Jamie Liu
PiperOrigin-RevId: 343196927
2020-11-09Initialize references with a value of 1.Dean Deng
This lets us avoid treating a value of 0 as one reference. All references using the refsvfs2 template must call InitRefs() before the reference is incremented/decremented, or else a panic will occur. Therefore, it should be pretty easy to identify missing InitRef calls during testing. Updates #1486. PiperOrigin-RevId: 341411151
2020-11-03Fix more nogo testsTing-Yu Wang
PiperOrigin-RevId: 340536306
2020-11-03[vfs2] Do not drop inotify waiters across S/R.Dean Deng
The waits-for relationship between an epoll instance and an inotify fd should be restored. This fixes flaky inotify vfs2 tests. PiperOrigin-RevId: 340531367
2020-10-28Add logging option to leak checker.Dean Deng
Also refactor the template and CheckedObject interface to make this cleaner. Updates #1486. PiperOrigin-RevId: 339577120
2020-10-24Add leak checking to vfs2 structures that cannot use the refs_vfs2 template.Dean Deng
Updates #1486. PiperOrigin-RevId: 338832085
2020-10-23Support VFS2 save/restore.Jamie Liu
Inode number consistency checks are now skipped in save/restore tests for reasons described in greatest detail in StatTest.StateDoesntChangeAfterRename. They pass in VFS1 due to the bug described in new test case SimpleStatTest.DifferentFilesHaveDifferentDeviceInodeNumberPairs. Fixes #1663 PiperOrigin-RevId: 338776148
2020-10-23Rewrite reference leak checker without finalizers.Dean Deng
Our current reference leak checker uses finalizers to verify whether an object has reached zero references before it is garbage collected. There are multiple problems with this mechanism, so a rewrite is in order. With finalizers, there is no way to guarantee that a finalizer will run before the program exits. When an unreachable object with a finalizer is garbage collected, its finalizer will be added to a queue and run asynchronously. The best we can do is run garbage collection upon sandbox exit to make sure that all finalizers are enqueued. Furthermore, if there is a chain of finalized objects, e.g. A points to B points to C, garbage collection needs to run multiple times before all of the finalizers are enqueued. The first GC run will register the finalizer for A but not free it. It takes another GC run to free A, at which point B's finalizer can be registered. As a result, we need to run GC as many times as the length of the longest such chain to have a somewhat reliable leak checker. Finally, a cyclical chain of structs pointing to one another will never be garbage collected if a finalizer is set. This is a well-known issue with Go finalizers (https://github.com/golang/go/issues/7358). Using leak checking on filesystem objects that produce cycles will not work and even result in memory leaks. The new leak checker stores reference counted objects in a global map when leak check is enabled and removes them once they are destroyed. At sandbox exit, any remaining objects in the map are considered as leaked. This provides a deterministic way of detecting leaks without relying on the complexities of finalizers and garbage collection. This approach has several benefits over the former, including: - Always detects leaks of objects that should be destroyed very close to sandbox exit. The old checker very rarely detected these leaks, because it relied on garbage collection to be run in a short window of time. - Panics if we forgot to enable leak check on a ref-counted object (we will try to remove it from the map when it is destroyed, but it will never have been added). - Can store extra logging information in the map values without adding to the size of the ref count struct itself. With the size of just an int64, the ref count object remains compact, meaning frequent operations like IncRef/DecRef are more cache-efficient. - Can aggregate leak results in a single report after the sandbox exits. Instead of having warnings littered in the log, which were non-deterministically triggered by garbage collection, we can print all warning messages at once. Note that this could also be a limitation--the sandbox must exit properly for leaks to be detected. Some basic benchmarking indicates that this change does not significantly affect performance when leak checking is enabled, which is understandable since registering/unregistering is only done once for each filesystem object. Updates #1486. PiperOrigin-RevId: 338685972
2020-10-13[vfs2] Don't take reference in Task.MountNamespaceVFS2 and MountNamespace.Root.Dean Deng
This fixes reference leaks related to accidentally forgetting to DecRef() after calling one or the other. PiperOrigin-RevId: 336918922
2020-10-13[vfs2] Add FilesystemType.Release to avoid reference leaks.Dean Deng
Singleton filesystem like devpts and devtmpfs have a single filesystem shared among all mounts, so they acquire a "self-reference" when initialized that must be released when the entire virtual filesystem is released at sandbox exit. PiperOrigin-RevId: 336828852
2020-10-12Change Merkle tree library to use ReaderAtChong Cai
Merkle tree library was originally using Read/Seek to access data and tree, since the parameters are io.ReadSeeker. This could cause race conditions if multiple threads accesses the same fd to read. Here we change to use ReaderAt, and implement it with PRead to make it thread safe. PiperOrigin-RevId: 336779260
2020-10-12[vfs2] Don't leak disconnected mounts.Dean Deng
PiperOrigin-RevId: 336694658
2020-10-02Convert uses of the binary package in kernel to go-marshal.Rahat Mahmood
PiperOrigin-RevId: 335077195
2020-09-24Add basic stateify annotations.Adin Scannell
Updates #1663 PiperOrigin-RevId: 333539293
2020-09-23Add more descriptive comments on mount options.Dean Deng
PiperOrigin-RevId: 333447255