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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
2021-04-26nogo: enable bazel workers and other optimizations.Adin Scannell
This is a suite of changes intended to dramatically speed up nogo speed. First, there are minor changes that help efficiency significantly. * Gob-based encoding is used internally, and JSON only used for the final set of findings. This is done to preserve the existing format (which is consumed by external tooling), and to facilitate manual debugging. * Unnecessary regex compilation is elided in the configuration, and care is taken for merges to prevent redundant entries. I'm not sure quite sure how, but it turns out that this was consumed a significant amount of time, presumably compiling the same regexes over and over again. Second, this change enables bazel workers for nogo analyzers. Workers enable persistent processes instead of creating and tearing down a sandbox every invocation. A library is introduced to abstraction these details, and allow the tools to still be written using standard flags, etc. The key here is that these binaries and the core of nogo become aware of caches with worker.Cache. This allows us to save significant time loading the same set of files and findings over and over again. These caches are keyed by the digests that are provided by bazel, and are capped in overall size. Note that the worker package attempts to capture output during each run, but tools are no longer permitted to write to stdout. This necessitated dropping some spurious output from checklocks. PiperOrigin-RevId: 370505732
2021-04-23Improve nogo action cache-ability.Adin Scannell
Presently, the standard library facts are not serialized in a deterministic order. This means that they have the possibility to change on each iteration, requiring a large scale re-analysis of all downstream actions, which includes all packages. Improve cache-ability of nogo actions by improving the determinism of the both facts and findings. Internally, default facts should be serialized as a sorted list for this reason already. PiperOrigin-RevId: 370188259
2021-04-20Clean test tags.Adin Scannell
PiperOrigin-RevId: 369505182
2021-04-08Drop unused escapes information.Adin Scannell
PiperOrigin-RevId: 367517305
2021-04-02Internal change.gVisor bot
PiperOrigin-RevId: 366555466
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
2021-02-02Remove go_tool_library references.Adin Scannell
This is required only for the built-in bazel nogo functionality. Since we roll these targets manually via the wrappers, we don't need to use go_tool_library. The inconsistent use of these targets leads to conflicting instantiations of go_default_library and go_tool_library, which both contain the same output files. PiperOrigin-RevId: 355184975
2021-01-05Add YAML validation for configuration files.Adin Scannell
For validation, the "on" key in existing YAML files is changed to a literal string. In the YAML spec, on is a keyword which encodes a boolean value, so without relying on a specific implementation the YAML files are technically not encoding an object that complies with the specification. PiperOrigin-RevId: 350172147
2020-12-11Remove existing nogo exceptions.Adin Scannell
PiperOrigin-RevId: 347047550
2020-10-28Traversal embedded libraries, even for go_library rules.Adin Scannell
PiperOrigin-RevId: 339570821
2020-10-26Add nogo configuration.Adin Scannell
This splits the nogo rules into a separate configuration yaml file, and allows for multiple files to be provided. Because attrs cannot be passed down to aspects, this required that all findings are propagated up the aspect Provider. This doesn't mean that any extra work must be done, just that this information must be carried through the graph, and some additional starlark complexity is required. PiperOrigin-RevId: 339076357
2020-10-23Fix nogo tests in //pkg/sentry/socket/...Ting-Yu Wang
PiperOrigin-RevId: 338784921
2020-10-23//pkg/state fixes for VFS2.Jamie Liu
- When encodeState.resolve() determines that the resolved reflect.Value is contained by a previously-resolved object, set wire.Ref.Type to the containing object's type (existing.obj.Type()) rather than the contained value's type (obj.Type()). - When encodeState.resolve() determines that the resolved reflect.Value contains a previously-resolved object, handle cases where the new object contains *multiple* previously-resolved objects. (This may cause previously-allocated object IDs to become unused; to facilitate this, change encodeState.pending to a map, and change the wire format to prefix each object with its object ID.) - Add encodeState.encodedStructs to avoid redundant encoding of structs, since deduplication of objects via encodeState.resolve() doesn't work for objects instantiated by StateSave() and passed to SaveValue() (i.e. fields tagged `state:".(whatever)"`). - Make unexported array fields deserializable via slices that refer to them by casting away their unexportedness in decodeState.decodeObject(). Updates #1663 PiperOrigin-RevId: 338727687
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
2020-10-20Fix nogo test in //pkg/tcpip/...Ting-Yu Wang
PiperOrigin-RevId: 338168977
2020-10-19Remove legacy bazel configurations.Adin Scannell
Using the newer bazel rules necessitates a transition from proto1 to proto2. In order to resolve the incompatibility between proto2 and gogoproto, the cri runtimeoptions proto must be vendored. Further, some of the semantics of bazel caching changed during the transition. It is now necessary to: - Ensure that :gopath depends only on pure library targets, as the propagation of go_binary build attributes (pure, static) will affected the generated files (though content remains the same, there are conflicts with respect to the gopath). - Update bazel.mk to include the possibility of binaries in the bazel-out directory, as it will now put runsc and others there. This required some refinements to the mechanism of extracting paths, since some the existing regex resulted in false positives. - Change nogo rules to prevent escape generation on binary targets. For some reason, the newer version of bazel attempted to run the nogo analysis on the binary targets, which fails due to the fact that objdump does not work on the final binary. This must be due to a change in the semantics of aspects in bazel3. PiperOrigin-RevId: 337958324
2020-10-16Refactor shared starlark files.Adin Scannell
PiperOrigin-RevId: 337581114
2020-10-16Refactor nogo to better support ARM.Adin Scannell
PiperOrigin-RevId: 337544107
2020-10-16Cache errors when processing stdlib with nogo.Adin Scannell
PiperOrigin-RevId: 337515664
2020-10-09Minor nogo restructuring.Adin Scannell
PiperOrigin-RevId: 336343819
2020-10-08Minor nogo cleanup.Adin Scannell
PiperOrigin-RevId: 336126583
2020-10-07Add staticcheck and staticstyle analyzers.Adin Scannell
This change also adds support to go_stateify for detecting an appropriate receiver name, avoiding a large number of false positives. PiperOrigin-RevId: 335994587
2020-09-29Add nogo check annotations to GitHub.Adin Scannell
When nogo checks are violated, they will automatically posted as annotations on the specific GitHub commit. This allows us to ensure analysis & style rules and have them called out. PiperOrigin-RevId: 334447285
2020-09-11Make nogo more robust to variety of stdlib layouts.Michael Pratt
PiperOrigin-RevId: 331206424
2020-08-31Change nogo failures to test failures, instead of build failures.Adin Scannell
PiperOrigin-RevId: 329408633
2020-08-26Support stdlib analyzers with nogo.Adin Scannell
This immediately revealed an escape analysis violation (!), where the sync.Map was being used in a context that escapes were not allowed. This is a relatively minor fix and is included. PiperOrigin-RevId: 328611237
2020-08-25Add nogo support to go_binary and go_test targets.Adin Scannell
Updates #3374 PiperOrigin-RevId: 328378700
2020-08-06Add bzl_library rules for .bzl files without one.Adin Scannell
PiperOrigin-RevId: 325280924
2020-07-23Internal changeMichael Pratt
PiperOrigin-RevId: 322788791
2020-07-13Merge pull request #2672 from amscanne:shim-integratedgVisor bot
PiperOrigin-RevId: 321053634
2020-06-18Remove various uses of 'whitelist'Michael Pratt
Updates #2972 PiperOrigin-RevId: 317113059
2020-06-17Remove various uses of 'blacklist'Michael Pratt
Updates #2972 PiperOrigin-RevId: 316942245
2020-04-22Specify a memory file in platform.New().Andrei Vagin
PiperOrigin-RevId: 307941984
2020-04-20Add internal nogo analysis & checkescape tool.Adin Scannell
See tools/nogo/README.md. The checkescape tool is able to perform recursive escape analysis, using the actual generated binary to confirm the results produced by the compiler itself. As an initial use case, this replaces the manual escape analysis tests used for go_marshal, and validates that the CopyIn and CopyOut paths will not require any allocation or stack splits. Updates #2243 PiperOrigin-RevId: 307532986