We had been repeating conditions for specific platforms and
architectures to gate fuzzing tests, but the more of those tests we
add the more we will have to update if the set of supported platforms
and archictures expands over time.
We also ought to provide a friendlier error message when
'go test -fuzz' is used on non-supported platforms.
This change adds predicates in cmd/internal/sys, which already
contains similar predicates for related functionality (such as the
race detector), and uses those predicates in 'go test' and TestScript.
For #48495
Change-Id: If24c3997aeb4d201258e21e5b6cf4f7c08fbadd7
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This change also does some refactors around how
we prevent many (*F) methods from being called
inside (*F).Fuzz. Previously, there was a lot of
comment/code duplication, which was going to be
difficult to maintain and brittle. The refactor
lessens this duplication.
Previously, the methods Log, Logf, Failed, Name and
Skipped were the only (*common) methods that were
allowed to be called inside (*F).Fuzz. After this
change, Failed and Name are still allowed, but
Log, Logf, and Skipped are not (t.Log, t.Logf, or
t.Skipped should be used instead).
Fixes#48988
Change-Id: I4066247d551ea1908e8a2ca2889509fc68e3bb44
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Tests that require instrumentation must be in
a test script which only runs for architectures
where coverage is supported.
Change-Id: Ia56b1cef1071f848c9dce8c87597207937fdb6c9
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This change also fixes a bug with calculating the
total interesting count. When fuzzing with an empty
corpus, the fuzzing engine adds an starting corpus
value in that run in order to start fuzzing. That
meant that the interesting total count was off by one:
it would start at 1, even though the cache was empty.
Added some tests for this as well.
Fixes#48787
Change-Id: I47acf96f0a0797214ebb24a95366d8460bf303bc
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Based on comments in CL 348469.
Note that with this change, F.Fuzz no longer calls
runtime.Goexit. This simplifies our logic and makes F.Fuzz more
predictable.
Change-Id: I6c3c65b0e8e8f261621cbe2f17375e8164ef60a0
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This reverts commit 413c125da3.
Reason for revert: Giving this more thought, we've decided that
converting types under the hood may cause unexpected behavior to
users. This is a feature that can always be added after more
consideration has been done, but is not something that can be
removed due to the backwards compatibility promise.
Updates golang/go#45593
Change-Id: I79bab24979d7e4c294e6cb6455d4c7729d6a0efb
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The coordinator needs to marshal data that was provided
via f.Add. However, it was also attempting to marshal data
that was in testdata, which was not needed,
and was causing a panic. This change fixes this.
Fixesgolang/go#48228
Change-Id: I1256c5a287b5a09d2f8cca59beb0f0fc06cc3554
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The types provided in f.Fuzz will be viewed as the
canonical types for fuzzing. If the type is different
for a seed corpus entry, then the testing package
will attempt to convert it. If it can't convert it,
f.Fuzz will fail.
Currently, this allows converting types that may result
in precision loss or a semantically different value.
For example, an int(-1) can be converted to uint even
though the value could be math.MaxUint64. There is a
TODO to consider improving this in the future.
Updates golang/go#45593
Change-Id: I2e752119662f46b68445d42b1ffa46dd30e9faea
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There was a bug where if the types to fuzz were
different from the types in a file in the on-disk
corpus, then the code would panic. We thought
this case was handled, but the final `continue`
in the nested loop still allowed the invalid
entry to be added to the corpus. Pulling the
validation into a helper function makes this
less brittle.
Change-Id: I401346f890ea30ab7cff9640cb555da2e3ff8cc6
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-fuzztime now works similarly to -benchtime: if it's given a string
with an "x" suffix (as opposed to "s" or some other unit of
duration), the fuzzing system will generate and run a maximum number
of values.
This CL also implements tracking and printing counts, since most of
the work was already done.
Change-Id: I013007984b5adfc1a751c379dc98c8d46b4a97e9
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CoordinateFuzzing now continues to run after discovering a crasher. It
waits until all workers have terminated before returning.
This fixes a deadlock that occurred when multiple workers discovered
crashers concurrently. CoordinateFuzzing would receive one crasher,
close doneC (telling workers to stop), then wait for workers to stop
without receiving more crashers. Other workers would block sending
crashers.
Change-Id: I55a64aac0e6e43f5e36b9d03c15051c3d5debb20
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This change makes several refactors to start supporting
structured fuzzing. The mutator can still only mutate
byte slices, and future changes will be made to support
mutating other types. However, it does now support
fuzzing more than one []byte.
This change also makes it so that corpus entries are
encoded in the new file format when being written to
testdata or GOCACHE. Any existing GOCACHE data should
be deleted from your local workstation to allow tests
to pass locally.
Change-Id: Iab8fe01a5dc870f0c53010b9d5b0b479bbdb310d
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This change rewrites much of the glue code in testing/fuzz.go to work
more analogously to T.Run. This results in improved behavior:
* If a fuzz target returns without calling F.Skip, F.Fail, or F.Fuzz,
'go test' will report an error and exit non-zero.
* Functions registered with F.Cleanup are called.
* The user can re-run individual inputs using -run=FuzzTarget/name
where name is the base name of the seed corpus file. We now print
the 'go test' command after a crash.
This change doesn't correctly handle T.Parallel calls yet, but it
should be easier to do that in the future.
Highlighted parts of this change:
* Instead of creating one F for all targets, create an F for each
target. F (actually common) holds the status, output, and cleanup
function list for each target, so it's important to keep them
separate.
* Run each target in its own goroutine via fRunner. fRunner is
analogous to tRunner. It runs cleanups and catches inappropriate
Goexits and panics.
* Run each input in its own goroutine via T.Run. This enables subtest
filtering with -test.run and ensures functions registered with
T.Cleanup (not F.Cleanup) are run at the appropriate time.
Change-Id: Iab1da14ead8bcb57746f8a76f4aebc625baa5792
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Fuzz targets must call F.Skip, F.Fail, or F.Fuzz. F.Fuzz must not be
called more than once. If a fuzz target panics, calls runtime.Goexit,
or returns normally without calling one of those functions, the target
should panic, and 'go test' should exit with a non-zero status.
For now, this isn't checked. It will be fixed in a follow-up CL.
Change-Id: Ibb905954462b64af15332c285124d78a998f7762
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For now, fuzzing is only supported on Darwin, Linux, and Windows. We
haven't testing shared memory communication between coordinator and
worker processes on other platforms. Currently, fuzz.CoordinateFuzzing
and RunFuzzWorker both panic with "unimplemented" messages.
Unfortunately, these may be masked by runtime.Goexit calls that
override panics, so some builders fail with
test executed panic(nil) or runtime.Goexit
Change-Id: Ic7bd692461958626dd5c5bb31198aec86387bbd6
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fuzz.CoordinateFuzzing and RunFuzzWorker now accept a context.Context
parameter. They should terminate gracefully when the context is
cancelled. The worker should exit quickly without processing more
inputs. The coordinator should save interesting inputs to the cache.
The testing package can't import context directly, so it provides a
timeout argument to testdeps.CoordinateFuzzing instead. The testdeps
wrapper sets the timeout and installs an interrupt handler (for SIGINT
on POSIX and the equivalent on Windows) that cancels the context when
^C is pressed.
Note that on POSIX platforms, pressing ^C causes the shell to deliver
SIGINT to all processes in the active group: so 'go test', the
coordinator, and the workers should all react to that. On Windows,
pressing ^C only interrupts 'go test'. We may want to look at that
separately.
Change-Id: I924d3be2905f9685dae82ff3c047ca3d6b5e2357
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This change also includes a small cleanup of the run()
function and additional tests for error conditions
in fuzz targets.
Change-Id: I2b7722b25a0d071182a84f1dc4b92e82a7ea34d9
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This change causes f.Fuzz to call runtime.GoExit
when it has finished running. This would mean that
any code after an f.Fuzz function within a fuzz
target would not be executed.
In the future, vet should fail if someone tries to
do this.
This change also adds the missing code that would
execute any cleanup functions added by f.Cleanup.
Change-Id: Ib4d1e6bcafbe189986d0667a1e87dabae67ee621
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