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| author | Steven Johnstone <steven.james.johnstone@gmail.com> | 2022-03-10 13:38:00 +0000 |
|---|---|---|
| committer | Dmitri Shuralyov <dmitshur@golang.org> | 2022-03-14 16:31:27 +0000 |
| commit | d69d093c77250a58c648756db42bbad8ad823770 (patch) | |
| tree | 6b5c48cfcee0480352270056a7be489ff67155b0 | |
| parent | c79ccd88ab65d4db6a5cf1875cf4d963b9e4fe0b (diff) | |
| download | go-d69d093c77250a58c648756db42bbad8ad823770.tar.gz go-d69d093c77250a58c648756db42bbad8ad823770.zip | |
[release-branch.go1.18] internal/fuzz: minimization should not reduce coverage
Minimization should result in a fuzz input which
includes the same coverage bits as the original
input.
Updates #48326
Change-Id: I6c5f30058b57ccd1a096ad0e9452a4dfbb7d9aab
Reviewed-on: https://go-review.googlesource.com/c/go/+/391454
Trust: Bryan Mills <bcmills@google.com>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Run-TryBot: Roland Shoemaker <roland@golang.org>
Auto-Submit: Roland Shoemaker <roland@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
(cherry picked from commit 5003ed884a67ee26b4cedbe6f5b1c02bd5eb6630)
Reviewed-on: https://go-review.googlesource.com/c/go/+/391798
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
| -rw-r--r-- | src/cmd/go/testdata/script/test_fuzz_minimize_interesting.txt | 11 | ||||
| -rw-r--r-- | src/internal/fuzz/coverage.go | 11 | ||||
| -rw-r--r-- | src/internal/fuzz/worker.go | 3 |
3 files changed, 13 insertions, 12 deletions
diff --git a/src/cmd/go/testdata/script/test_fuzz_minimize_interesting.txt b/src/cmd/go/testdata/script/test_fuzz_minimize_interesting.txt index 5d0de17f6b..a09e85b972 100644 --- a/src/cmd/go/testdata/script/test_fuzz_minimize_interesting.txt +++ b/src/cmd/go/testdata/script/test_fuzz_minimize_interesting.txt @@ -127,19 +127,8 @@ func FuzzMinCache(f *testing.F) { if bytes.Equal(buf, seed) { return } - if n := sum(buf); n < 0 { - t.Error("sum cannot be negative") - } }) } - -func sum(buf []byte) int { - n := 0 - for _, b := range buf { - n += int(b) - } - return n -} -- check_testdata/check_testdata.go -- //go:build ignore // +build ignore diff --git a/src/internal/fuzz/coverage.go b/src/internal/fuzz/coverage.go index 3dee73b81c..88f98a16b2 100644 --- a/src/internal/fuzz/coverage.go +++ b/src/internal/fuzz/coverage.go @@ -66,6 +66,17 @@ func countNewCoverageBits(base, snapshot []byte) int { return n } +// isCoverageSubset returns true if all the base coverage bits are set in +// snapshot +func isCoverageSubset(base, snapshot []byte) bool { + for i, v := range base { + if v&snapshot[i] != v { + return false + } + } + return true +} + // hasCoverageBit returns true if snapshot has at least one bit set that is // also set in base. func hasCoverageBit(base, snapshot []byte) bool { diff --git a/src/internal/fuzz/worker.go b/src/internal/fuzz/worker.go index 83d937ee6d..6e4c4e2d0f 100644 --- a/src/internal/fuzz/worker.go +++ b/src/internal/fuzz/worker.go @@ -894,7 +894,8 @@ func (ws *workerServer) minimizeInput(ctx context.Context, vals []any, mem *shar } return true } - if keepCoverage != nil && hasCoverageBit(keepCoverage, coverageSnapshot) { + // Minimization should preserve coverage bits. + if keepCoverage != nil && isCoverageSubset(keepCoverage, coverageSnapshot) { return true } vals[args.Index] = prev |