fuzzing: Add supportsErrorInjection option to DawnWireServerFuzzer

This option will be used by backends that support error injection so
that errors can be injected into a "clean" corpus to generate a seed
corpus with good examples of injected error conditions.

Bug: dawn:295
Change-Id: I837acdde6dd4274adb56edf8e4307427f8d6333b
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/14681
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Austin Eng <enga@chromium.org>

docs/fuzzing.md

@@ -4,17 +4,23 @@
 
 The `dawn_wire_server_and_frontend_fuzzer` sets up Dawn using the Null backend, and passes inputs to the wire server. This fuzzes the `dawn_wire` deserialization, as well as Dawn's frontend validation.
 
+## `dawn_wire_server_and_vulkan_backend_fuzzer`
+
+The `dawn_wire_server_and_vulkan_backend_fuzzer` is like `dawn_wire_server_and_frontend_fuzzer` but it runs using a Vulkan CPU backend such as Swiftshader. This fuzzer supports error injection by using the first bytes of the fuzzing input as a Vulkan call index for which to mock a failure.
+
 ## Updating the Seed Corpus
 
 Using a seed corpus significantly improves the efficiency of fuzzing. Dawn's fuzzers use interesting testcases discovered in previous fuzzing runs to seed future runs. Fuzzing can be further improved by using Dawn tests as a example of API usage which allows the fuzzer to quickly discover and use new API entrypoints and usage patterns.
 
-The script [update_fuzzer_seed_corpus.sh](../scripts/update_fuzzer_seed_corpus.sh) can be used to capture a trace while running Dawn tests, and upload it to the existing fuzzzer seed corpus.
+The script [update_fuzzer_seed_corpus.sh](../scripts/update_fuzzer_seed_corpus.sh) can be used to capture a trace while running Dawn tests, and upload it to the existing fuzzer seed corpus. It does the following steps:
+1. Builds the provided test and fuzzer targets.
+2. Runs the provided test target with `--use-wire --wire-trace-dir=tmp_dir1 [additional_test_args]` to dump traces of the tests.
+3. Generates one variant of each trace for every possible error index, by running the fuzzer target with `--injected-error-testcase-dir=tmp_dir2 ...`.
+4. Minimizes all testcases by running the fuzzer target with `-merge=1 tmp_dir3 tmp_dir1 tmp_dir2`.
 
 To run the script:
-1. Make sure gcloud is installed: https://g3doc.corp.google.com/cloud/sdk/g3doc/index.md?cl=head
+1. You must be in a Chromium checkout using the GN arg `use_libfuzzer=true`
-2. Login with @google.com credentials: `gcloud auth login`
+2. Run `./third_party/dawn/scripts/update_fuzzer_seed_corpus.sh <out_dir> <fuzzer> <test> [additional_test_args]`.
-3. You must be in a Chromium checkout using the GN arg `use_libfuzzer=true`
-4. Run `./third_party/dawn/scripts/update_fuzzer_seed_corpus.sh <out_dir> <fuzzer> <test>`.
 
-   Example: `./third_party/dawn/scripts/update_fuzzer_seed_corpus.sh out/fuzz dawn_wire_server_and_frontend_fuzzer dawn_end2end_tests`
+   Example: `./third_party/dawn/scripts/update_fuzzer_seed_corpus.sh out/fuzz dawn_wire_server_and_vulkan_backend_fuzzer dawn_end2end_tests --gtest_filter=*Vulkan`
-5. The script will print instructions for testing, and then uploading new inputs. Please, only upload inputs after testing the fuzzer with new inputs, and verifying there is a meaningful change in coverage.
+3. The script will print instructions for testing, and then uploading new inputs. Please, only upload inputs after testing the fuzzer with new inputs, and verifying there is a meaningful change in coverage. Uploading requires [gcloud](https://g3doc.corp.google.com/cloud/sdk/g3doc/index.md?cl=head) to be logged in with @google.com credentials: `gcloud auth login`.

scripts/update_fuzzer_seed_corpus.sh

@@ -20,29 +20,39 @@
 # Exit if anything fails
 set -e
 
-if [ "$#" -ne 3 ]; then
+if [ "$#" -lt 3 ]; then
 cat << EOF
 
 Usage:
-  $0 <out_dir> <fuzzer_name> <test_name>
+  $0 <out_dir> <fuzzer_name> <test_name> [additional_test_args...]
 
 Example:
-  $0 out/fuzz dawn_wire_server_and_frontend_fuzzer dawn_end2end_tests
+  $0 out/fuzz dawn_wire_server_and_vulkan_backend_fuzzer dawn_end2end_tests --gtest_filter=*Vulkan
 
 EOF
     exit 1
 fi
 
+all_args=("$@")
 out_dir=$1
 fuzzer_name=$2
 test_name=$3
+additional_test_args=("${all_args[@]:3}")
 
 testcase_dir="/tmp/testcases/${fuzzer_name}/"
+injected_error_testcase_dir="/tmp/testcases/${fuzzer_name}_injected/"
 minimized_testcase_dir="/tmp/testcases/${fuzzer_name}_minimized/"
 
+# Print commands so it's clear what is being executed
+set -x
+
 # Make a directory for temporarily storing testcases
 mkdir -p "$testcase_dir"
 
+# Make an empty directory for temporarily storing testcases with injected errors
+rm -rf "$injected_error_testcase_dir"
+mkdir -p "$injected_error_testcase_dir"
+
 # Make an empty directory for temporarily storing minimized testcases
 rm -rf "$minimized_testcase_dir"
 mkdir -p "$minimized_testcase_dir"
@@ -54,10 +64,16 @@ fuzzer_binary="${out_dir}/${fuzzer_name}"
 test_binary="${out_dir}/${test_name}"
 
 # Run the test binary
-$test_binary --use-wire --wire-trace-dir="$testcase_dir"
+$test_binary --use-wire --wire-trace-dir="$testcase_dir" $additional_test_args
 
-# Run the fuzzer to minimize the corpus
+# Run the fuzzer over the testcases to inject errors
-$fuzzer_binary -merge=1 "$minimized_testcase_dir" "$testcase_dir"
+$fuzzer_binary --injected-error-testcase-dir="$injected_error_testcase_dir" -runs=0 "$testcase_dir"
+
+# Run the fuzzer to minimize the testcases + injected errors
+$fuzzer_binary -merge=1 "$minimized_testcase_dir" "$injected_error_testcase_dir" "$testcase_dir"
+
+# Turn off command printing
+set +x
 
 if [ -z "$(ls -A $minimized_testcase_dir)" ]; then
 cat << EOF

src/dawn_native/ErrorInjector.cpp

@@ -15,6 +15,7 @@
 #include "dawn_native/ErrorInjector.h"
 
 #include "common/Assert.h"
+#include "dawn_native/DawnNative.h"
 
 namespace dawn_native {
 

src/dawn_native/ErrorInjector.h

@@ -26,12 +26,7 @@ namespace dawn_native {
         bool injected;
     };
 
-    void EnableErrorInjector();
-    void DisableErrorInjector();
-    void ClearErrorInjector();
-
     bool ErrorInjectorEnabled();
-    uint64_t AcquireErrorInjectorCallCount();
 
     bool ShouldInjectError();
 
@@ -48,8 +43,6 @@ namespace dawn_native {
         return MaybeInjectError(errorTypes...);
     }
 
-    void InjectErrorAt(uint64_t index);
-
 }  // namespace dawn_native
 
 #if defined(DAWN_ENABLE_ERROR_INJECTION)

src/fuzzers/DawnSPIRVCrossGLSLFastFuzzer.cpp

@@ -45,6 +45,10 @@ namespace {
 
 }  // namespace
 
+extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {
+    return 0;
+}
+
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
     return DawnSPIRVCrossFuzzer::Run(data, size, GLSLFastFuzzTask);
 }

src/fuzzers/DawnSPIRVCrossHLSLFastFuzzer.cpp

@@ -51,6 +51,10 @@ namespace {
 
 }  // namespace
 
+extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {
+    return 0;
+}
+
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
     return DawnSPIRVCrossFuzzer::Run(data, size, FuzzTask);
 }

src/fuzzers/DawnSPIRVCrossMSLFastFuzzer.cpp

@@ -44,6 +44,10 @@ namespace {
 
 }  // namespace
 
+extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {
+    return 0;
+}
+
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
     return DawnSPIRVCrossFuzzer::Run(data, size, FuzzTask);
 }

src/fuzzers/DawnSPVCglslFastFuzzer.cpp

@@ -18,6 +18,10 @@
 
 #include "spvc/spvc.hpp"
 
+extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {
+    return 0;
+}
+
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
     shaderc_spvc::Context context;
     if (!context.IsValid()) {

src/fuzzers/DawnSPVChlslFastFuzzer.cpp

@@ -18,6 +18,10 @@
 
 #include "spvc/spvc.hpp"
 
+extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {
+    return 0;
+}
+
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
     shaderc_spvc::Context context;
     if (!context.IsValid()) {

src/fuzzers/DawnSPVCmslFastFuzzer.cpp

@@ -18,6 +18,10 @@
 
 #include "spvc/spvc.hpp"
 
+extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {
+    return 0;
+}
+
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
     shaderc_spvc::Context context;
     if (!context.IsValid()) {

src/fuzzers/DawnWireServerAndFrontendFuzzer.cpp

@@ -17,21 +17,28 @@
 #include "common/Assert.h"
 #include "dawn_native/DawnNative.h"
 
-extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {
-    return DawnWireServerFuzzer::Run(data, size, [](dawn_native::Instance* instance) {
+    return DawnWireServerFuzzer::Initialize(argc, argv);
-        instance->DiscoverDefaultAdapters();
+}
-
+
-        std::vector<dawn_native::Adapter> adapters = instance->GetAdapters();
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-
+    return DawnWireServerFuzzer::Run(
-        wgpu::Device nullDevice;
+        data, size,
-        for (dawn_native::Adapter adapter : adapters) {
+        [](dawn_native::Instance* instance) {
-            if (adapter.GetBackendType() == dawn_native::BackendType::Null) {
+            instance->DiscoverDefaultAdapters();
-                nullDevice = wgpu::Device::Acquire(adapter.CreateDevice());
+
-                break;
+            std::vector<dawn_native::Adapter> adapters = instance->GetAdapters();
-            }
+
-        }
+            wgpu::Device nullDevice;
-
+            for (dawn_native::Adapter adapter : adapters) {
-        ASSERT(nullDevice.Get() != nullptr);
+                if (adapter.GetBackendType() == dawn_native::BackendType::Null) {
-        return nullDevice;
+                    nullDevice = wgpu::Device::Acquire(adapter.CreateDevice());
-    });
+                    break;
+                }
+            }
+
+            ASSERT(nullDevice.Get() != nullptr);
+            return nullDevice;
+        },
+        false /* supportsErrorInjection */);
 }

src/fuzzers/DawnWireServerAndVulkanBackendFuzzer.cpp

@@ -14,25 +14,29 @@
 
 #include "DawnWireServerFuzzer.h"
 
-#include "common/Assert.h"
 #include "dawn_native/DawnNative.h"
 
-extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {
-    return DawnWireServerFuzzer::Run(data, size, [](dawn_native::Instance* instance) {
+    return DawnWireServerFuzzer::Initialize(argc, argv);
-        instance->DiscoverDefaultAdapters();
+}
-
+
-        std::vector<dawn_native::Adapter> adapters = instance->GetAdapters();
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-
+    return DawnWireServerFuzzer::Run(
-        wgpu::Device device;
+        data, size,
-        for (dawn_native::Adapter adapter : adapters) {
+        [](dawn_native::Instance* instance) {
-            if (adapter.GetBackendType() == dawn_native::BackendType::Vulkan &&
+            instance->DiscoverDefaultAdapters();
-                adapter.GetDeviceType() == dawn_native::DeviceType::CPU) {
+
-                device = wgpu::Device::Acquire(adapter.CreateDevice());
+            std::vector<dawn_native::Adapter> adapters = instance->GetAdapters();
-                break;
+
-            }
+            wgpu::Device device;
-        }
+            for (dawn_native::Adapter adapter : adapters) {
-
+                if (adapter.GetBackendType() == dawn_native::BackendType::Vulkan &&
-        ASSERT(device.Get() != nullptr);
+                    adapter.GetDeviceType() == dawn_native::DeviceType::CPU) {
-        return device;
+                    device = wgpu::Device::Acquire(adapter.CreateDevice());
-    });
+                    break;
+                }
+            }
+            return device;
+        },
+        true /* supportsErrorInjection */);
 }

src/fuzzers/DawnWireServerFuzzer.cpp

@@ -15,11 +15,14 @@
 #include "DawnWireServerFuzzer.h"
 
 #include "common/Assert.h"
+#include "common/Log.h"
+#include "common/SystemUtils.h"
 #include "dawn/dawn_proc.h"
 #include "dawn/webgpu_cpp.h"
 #include "dawn_native/DawnNative.h"
 #include "dawn_wire/WireServer.h"
 
+#include <fstream>
 #include <vector>
 
 namespace {
@@ -42,6 +45,9 @@ namespace {
 
     WGPUProcDeviceCreateSwapChain sOriginalDeviceCreateSwapChain = nullptr;
 
+    std::string sInjectedErrorTestcaseOutDir;
+    uint64_t sOutputFileNumber = 0;
+
     WGPUSwapChain ErrorDeviceCreateSwapChain(WGPUDevice device, const WGPUSwapChainDescriptor*) {
         WGPUSwapChainDescriptor desc;
         desc.nextInChain = nullptr;
@@ -53,7 +59,61 @@ namespace {
 
 }  // namespace
 
-int DawnWireServerFuzzer::Run(const uint8_t* data, size_t size, MakeDeviceFn MakeDevice) {
+int DawnWireServerFuzzer::Initialize(int* argc, char*** argv) {
+    ASSERT(argc != nullptr && argv != nullptr);
+
+    // The first argument (the fuzzer binary) always stays the same.
+    int argcOut = 1;
+
+    for (int i = 1; i < *argc; ++i) {
+        constexpr const char kInjectedErrorTestcaseDirArg[] = "--injected-error-testcase-dir=";
+        if (strstr((*argv)[i], kInjectedErrorTestcaseDirArg) == (*argv)[i]) {
+            sInjectedErrorTestcaseOutDir = (*argv)[i] + strlen(kInjectedErrorTestcaseDirArg);
+            const char* sep = GetPathSeparator();
+            if (sInjectedErrorTestcaseOutDir.back() != *sep) {
+                sInjectedErrorTestcaseOutDir += sep;
+            }
+            // Log so that it's clear the fuzzer found the argument.
+            dawn::InfoLog() << "Generating injected errors, output dir is: \""
+                            << sInjectedErrorTestcaseOutDir << "\"";
+            continue;
+        }
+
+        // Move any unconsumed arguments to the next slot in the output array.
+        (*argv)[argcOut++] = (*argv)[i];
+    }
+
+    // Write the argument count
+    *argc = argcOut;
+
+    return 0;
+}
+
+int DawnWireServerFuzzer::Run(const uint8_t* data,
+                              size_t size,
+                              MakeDeviceFn MakeDevice,
+                              bool supportsErrorInjection) {
+    bool didInjectError = false;
+
+    if (supportsErrorInjection) {
+        dawn_native::EnableErrorInjector();
+
+        // Clear the error injector since it has the previous run's call counts.
+        dawn_native::ClearErrorInjector();
+
+        // If we're outputing testcases with injected errors, we run the fuzzer on the original
+        // input data, and prepend injected errors to it. In the case, where we're NOT outputing,
+        // we use the first bytes as the injected error index.
+        if (sInjectedErrorTestcaseOutDir.empty() && size >= sizeof(uint64_t)) {
+            // Otherwise, use the first bytes as the injected error index.
+            dawn_native::InjectErrorAt(*reinterpret_cast<const uint64_t*>(data));
+            didInjectError = true;
+
+            data += sizeof(uint64_t);
+            size -= sizeof(uint64_t);
+        }
+    }
+
     DawnProcTable procs = dawn_native::GetProcs();
 
     // Swapchains receive a pointer to an implementation. The fuzzer will pass garbage in so we
@@ -67,7 +127,11 @@ int DawnWireServerFuzzer::Run(const uint8_t* data, size_t size, MakeDeviceFn Mak
 
     std::unique_ptr<dawn_native::Instance> instance = std::make_unique<dawn_native::Instance>();
     wgpu::Device device = MakeDevice(instance.get());
-    ASSERT(device);
+    if (!device) {
+        // We should only ever fail device creation if an error was injected.
+        ASSERT(didInjectError);
+        return 0;
+    }
 
     DevNull devNull;
     dawn_wire::WireServerDescriptor serverDesc = {};
@@ -87,5 +151,27 @@ int DawnWireServerFuzzer::Run(const uint8_t* data, size_t size, MakeDeviceFn Mak
     device = nullptr;
     instance = nullptr;
 
+    // If we support error injection, and an output directory was provided, output copies of the
+    // original testcase data, prepended with the injected error index.
+    if (supportsErrorInjection && !sInjectedErrorTestcaseOutDir.empty()) {
+        const uint64_t injectedCallCount = dawn_native::AcquireErrorInjectorCallCount();
+
+        auto WriteTestcase = [&](uint64_t i) {
+            std::ofstream outFile(
+                sInjectedErrorTestcaseOutDir + "injected_error_testcase_" +
+                    std::to_string(sOutputFileNumber++),
+                std::ios_base::out | std::ios_base::binary | std::ios_base::trunc);
+            outFile.write(reinterpret_cast<const char*>(&i), sizeof(i));
+            outFile.write(reinterpret_cast<const char*>(data), size);
+        };
+
+        for (uint64_t i = 0; i < injectedCallCount; ++i) {
+            WriteTestcase(i);
+        }
+
+        // Also add a testcase where the injected error is so large no errors should occur.
+        WriteTestcase(std::numeric_limits<uint64_t>::max());
+    }
+
     return 0;
 }

src/fuzzers/DawnWireServerFuzzer.h

@@ -27,6 +27,8 @@ namespace DawnWireServerFuzzer {
 
     using MakeDeviceFn = std::function<wgpu::Device(dawn_native::Instance*)>;
 
-    int Run(const uint8_t* data, size_t size, MakeDeviceFn MakeDevice);
+    int Initialize(int* argc, char*** argv);
+
+    int Run(const uint8_t* data, size_t size, MakeDeviceFn MakeDevice, bool supportsErrorInjection);
 
 }  // namespace DawnWireServerFuzzer

src/fuzzers/StandaloneFuzzerMain.cpp

@@ -17,11 +17,17 @@
 #include <iostream>
 #include <vector>
 
+extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv);
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size);
 
 int main(int argc, char** argv) {
+    if (LLVMFuzzerInitialize(&argc, &argv)) {
+        std::cerr << "Failed to initialize fuzzer target" << std::endl;
+        return 1;
+    }
+
     if (argc != 2) {
-        std::cout << "Usage: <standalone reproducer> FILE" << std::endl;
+        std::cout << "Usage: <standalone reproducer> [options] FILE" << std::endl;
         return 1;
     }
 

src/include/dawn_native/DawnNative.h

@@ -161,6 +161,14 @@ namespace dawn_native {
 
     // Backdoor to get the order of the ProcMap for testing
     DAWN_NATIVE_EXPORT std::vector<const char*> GetProcMapNamesForTesting();
+
+    // ErrorInjector functions used for testing only. Defined in dawn_native/ErrorInjector.cpp
+    DAWN_NATIVE_EXPORT void EnableErrorInjector();
+    DAWN_NATIVE_EXPORT void DisableErrorInjector();
+    DAWN_NATIVE_EXPORT void ClearErrorInjector();
+    DAWN_NATIVE_EXPORT uint64_t AcquireErrorInjectorCallCount();
+    DAWN_NATIVE_EXPORT void InjectErrorAt(uint64_t index);
+
 }  // namespace dawn_native
 
 #endif  // DAWNNATIVE_DAWNNATIVE_H_