skia2/fuzz/oss_fuzz/FuzzSkRuntimeEffect.cpp
Brian Osman 78a845aa19 Remove declaration of obsolete runtime effect inlining API
Change-Id: I7be9a95bc190760245966c36ed088afd68108a5f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/371316
Auto-Submit: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-02-17 18:10:16 +00:00

87 lines
3.1 KiB
C++

/*
* Copyright 2020 Google, LLC
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "include/core/SkCanvas.h"
#include "include/core/SkPaint.h"
#include "include/core/SkSurface.h"
#include "include/effects/SkRuntimeEffect.h"
#include "src/gpu/GrShaderCaps.h"
#include "fuzz/Fuzz.h"
static constexpr size_t kReservedBytes = 256;
/**
* The fuzzer will take in the bytes and divide into two parts.
* original bytes : [... code bytes ... | 256 bytes]
* The first part is codeBytes, the original bytes minus 256 bytes, which will be treated
* as sksl code, intending to create SkRuntimeEffect.
* For the second part, it will first reserve 256 bytes and then allocate bytes with same size
* as effect->inputSize() to uniformBytes. The uniformBytes is intended to create makeShader().
* Note that if uniformBytes->size() != effect->inputSize() the shader won't be created.
*
* We fuzz twice, with two different settings for inlining in the SkSL compiler. By default, the
* compiler inlines most small to medium functions. This can hide bugs related to function-calling.
* So we run the fuzzer once with inlining disabled, and again with it enabled (aggressively).
* This gives us better coverage, and eases the burden on the fuzzer to inject useless noise into
* functions to suppress inlining.
*/
static bool FuzzSkRuntimeEffect_Once(sk_sp<SkData> bytes, const SkRuntimeEffect::Options& options) {
if (bytes->size() < kReservedBytes) {
return false;
}
sk_sp<SkData> codeBytes = SkData::MakeSubset(bytes.get(), 0, bytes->size() - kReservedBytes);
SkString shaderText{static_cast<const char*>(codeBytes->data()), codeBytes->size()};
SkRuntimeEffect::Result result = SkRuntimeEffect::Make(shaderText, options);
SkRuntimeEffect* effect = result.effect.get();
if (!effect || effect->uniformSize() > kReservedBytes) { // if there is not enough uniform bytes
return false;
}
sk_sp<SkData> uniformBytes =
SkData::MakeSubset(bytes.get(), bytes->size() - kReservedBytes, effect->uniformSize());
auto shader = effect->makeShader(uniformBytes, /*children=*/nullptr, /*childCount=*/0,
/*localMatrix=*/nullptr, /*isOpaque=*/false);
if (!shader) {
return false;
}
SkPaint paint;
paint.setShader(std::move(shader));
sk_sp<SkSurface> s = SkSurface::MakeRasterN32Premul(128, 128);
if (!s) {
return false;
}
s->getCanvas()->drawPaint(paint);
return true;
}
bool FuzzSkRuntimeEffect(sk_sp<SkData> bytes) {
// Inline nothing
SkRuntimeEffect::Options options;
options.inlineThreshold = 0;
bool result = FuzzSkRuntimeEffect_Once(bytes, options);
// Inline everything
options.inlineThreshold = std::numeric_limits<int>::max();
result = FuzzSkRuntimeEffect_Once(bytes, options) || result;
return result;
}
#if defined(SK_BUILD_FOR_LIBFUZZER)
extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
if (size > 3000) {
return 0;
}
auto bytes = SkData::MakeWithoutCopy(data, size);
FuzzSkRuntimeEffect(bytes);
return 0;
}
#endif