trusty: Retrieve coverage PCs from coverage record (e962930d) · Commits · e / os / android_system_core

trusty/coverage/Android.bp

+1 −0

Original line number	Diff line number	Diff line
		@@ -42,4 +42,5 @@ cc_test {
		"libbase",
		"liblog",
		],
		require_root: true,
		}

trusty/coverage/coverage.cpp

+111 −4

Original line number	Diff line number	Diff line
		@@ -16,12 +16,15 @@

		#define LOG_TAG "coverage"

		#include <android-base/file.h>
		#include <android-base/logging.h>
		#include <android-base/unique_fd.h>
		#include <assert.h>
		#include <stdio.h>
		#include <sys/mman.h>
		#include <sys/uio.h>
		#include <trusty/coverage/coverage.h>
		#include <trusty/coverage/record.h>
		#include <trusty/coverage/tipc.h>
		#include <trusty/tipc.h>

		@@ -137,12 +140,59 @@ Result<void> CoverageRecord::Open() {
		return {};
		}

		void CoverageRecord::Reset() {
		for (size_t i = 0; i < shm_len_; i++) {
		void CoverageRecord::ResetFullRecord() {
		auto header_region = GetRegionBounds(COV_START);
		if (!header_region) {
		// If the header cannot be parsed, we can't reset the proper region yet.
		return;
		}

		for (size_t i = header_region->second; i < shm_len_; i++) {
		((volatile uint8_t)shm_ + i) = 0;
		}
		}

		void CoverageRecord::ResetCounts() {
		volatile uint8_t* begin = nullptr;
		volatile uint8_t* end = nullptr;
		GetRawCounts(&begin, &end);

		for (volatile uint8_t* x = begin; x < end; x++) {
		*x = 0;
		}
		}

		void CoverageRecord::ResetPCs() {
		volatile uintptr_t* begin = nullptr;
		volatile uintptr_t* end = nullptr;
		GetRawPCs(&begin, &end);

		for (volatile uintptr_t* x = begin; x < end; x++) {
		*x = 0;
		}
		}

		Result<std::pair<size_t, size_t>> CoverageRecord::GetRegionBounds(uint32_t region_type) {
		assert(shm_);

		auto header = (volatile struct coverage_record_header*)shm_;

		if (header->type != COV_START) {
		return Error() << "Header not yet valid";
		}

		for (++header; header->type != COV_TOTAL_LENGTH; ++header) {
		if (header->type == region_type) {
		// Coverage record must end with a COV_TOTAL_LENGTH header entry, so
		// it is always safe to read the next entry since we don't iterate
		// over the COV_TOTAL_LENGTH entry.
		return {{header->offset, (header + 1)->offset}};
		}
		}

		return Error() << "Could not find coverage region type: " << region_type;
		}

		void CoverageRecord::GetRawData(volatile void begin, volatile void end) {
		assert(shm_);

		@@ -150,7 +200,35 @@ void CoverageRecord::GetRawData(volatile void begin, volatile void end) {
		end = (uint8_t)(*begin) + record_len_;
		}

		uint64_t CoverageRecord::CountEdges() {
		void CoverageRecord::GetRawCounts(volatile uint8_t begin, volatile uint8_t end) {
		auto region = GetRegionBounds(COV_8BIT_COUNTERS);
		if (!region) {
		*begin = 0;
		*end = 0;
		return;
		}

		assert(region->second <= record_len_);

		begin = (volatile uint8_t)shm_ + region->first;
		end = (volatile uint8_t)shm_ + region->second;
		}

		void CoverageRecord::GetRawPCs(volatile uintptr_t begin, volatile uintptr_t end) {
		auto region = GetRegionBounds(COV_INSTR_PCS);
		if (!region) {
		*begin = 0;
		*end = 0;
		return;
		}

		assert(region->second <= record_len_);

		begin = (volatile uintptr_t)((volatile uint8_t*)shm_ + region->first);
		end = (volatile uintptr_t)((volatile uint8_t*)shm_ + region->second);
		}

		uint64_t CoverageRecord::TotalEdgeCounts() {
		assert(shm_);

		uint64_t counter = 0;
		@@ -158,7 +236,7 @@ uint64_t CoverageRecord::CountEdges() {
		volatile uint8_t* begin = NULL;
		volatile uint8_t* end = NULL;

		GetRawData((volatile void)&begin, (volatile void)&end);
		GetRawCounts(&begin, &end);

		for (volatile uint8_t* x = begin; x < end; x++) {
		counter += *x;
		@@ -167,6 +245,35 @@ uint64_t CoverageRecord::CountEdges() {
		return counter;
		}

		Result<void> CoverageRecord::SaveSancovFile(const std::string& filename) {
		android::base::unique_fd output_fd(TEMP_FAILURE_RETRY(creat(filename.c_str(), 00644)));
		if (!output_fd.ok()) {
		return ErrnoError() << "Could not open sancov file";
		}

		uint64_t magic;
		if (sizeof(uintptr_t) == 8) {
		magic = 0xC0BFFFFFFFFFFF64;
		} else if (sizeof(uintptr_t) == 4) {
		magic = 0xC0BFFFFFFFFFFF32;
		}
		WriteFully(output_fd, &magic, sizeof(magic));

		volatile uintptr_t* begin = nullptr;
		volatile uintptr_t* end = nullptr;

		GetRawPCs(&begin, &end);

		for (volatile uintptr_t* pc_ptr = begin; pc_ptr < end; pc_ptr++) {
		uintptr_t pc = *pc_ptr;
		if (pc) {
		WriteFully(output_fd, &pc, sizeof(pc));
		}
		}

		return {};
		}

		} // namespace coverage
		} // namespace trusty
		} // namespace android

trusty/coverage/coverage_test.cpp

+11 −4

Original line number	Diff line number	Diff line
		@@ -14,6 +14,7 @@
		* limitations under the License.
		*/

		#include <android-base/stringprintf.h>
		#include <gtest/gtest.h>
		#include <trusty/coverage/coverage.h>
		#include <trusty/tipc.h>
		@@ -27,6 +28,7 @@ using std::unique_ptr;

		#define TIPC_DEV "/dev/trusty-ipc-dev0"
		#define TEST_SRV_PORT "com.android.trusty.sancov.test.srv"
		#define TEST_SRV_MODULE "srv.syms.elf"

		namespace android {
		namespace trusty {
		@@ -54,8 +56,8 @@ class CoverageTest : public ::testing::Test {
		};

		TEST_F(CoverageTest, CoverageReset) {
		record_->Reset();
		auto counter = record_->CountEdges();
		record_->ResetFullRecord();
		auto counter = record_->TotalEdgeCounts();
		ASSERT_EQ(counter, 0);
		}

		@@ -69,7 +71,7 @@ TEST_F(CoverageTest, TestServerCoverage) {

		for (size_t i = 1; i < sizeof(magic) * 8; i++) {
		/* Reset coverage */
		record_->Reset();
		record_->ResetCounts();

		/* Send message to test server */
		uint32_t msg = magic & ~(mask << i);
		@@ -81,10 +83,15 @@ TEST_F(CoverageTest, TestServerCoverage) {
		ASSERT_EQ(rc, sizeof(msg));

		/* Count number of non-unique blocks executed */
		auto counter = record_->CountEdges();
		auto counter = record_->TotalEdgeCounts();
		/* Each consecutive input should exercise more or same blocks */
		ASSERT_GE(counter, high_watermark);
		high_watermark = counter;

		auto sancov_filename = android::base::StringPrintf(
		"/data/local/tmp/" TEST_SRV_MODULE ".%d.sancov", getpid());
		auto res = record_->SaveSancovFile(sancov_filename);
		ASSERT_TRUE(res.ok());
		}

		ASSERT_GT(high_watermark, 0);

trusty/coverage/include/trusty/coverage/coverage.h

+15 −2

Original line number	Diff line number	Diff line
		@@ -35,13 +35,26 @@ class CoverageRecord {
		CoverageRecord(std::string tipc_dev, struct uuid* uuid);
		~CoverageRecord();
		Result<void> Open();
		void Reset();
		void ResetFullRecord();
		void ResetCounts();
		void ResetPCs();
		void GetRawData(volatile void begin, volatile void end);
		uint64_t CountEdges();
		void GetRawCounts(volatile uint8_t begin, volatile uint8_t end);
		void GetRawPCs(volatile uintptr_t begin, volatile uintptr_t end);
		uint64_t TotalEdgeCounts();

		/**
		* Save the current set of observed PCs to the given filename.
		* The resulting .sancov file can be parsed via the LLVM sancov tool to see
		* coverage statistics and visualize coverage.
		*/
		Result<void> SaveSancovFile(const std::string& filename);

		private:
		Result<void> Rpc(coverage_client_req* req, int req_fd, coverage_client_resp* resp);

		Result<std::pair<size_t, size_t>> GetRegionBounds(uint32_t region_type);

		std::string tipc_dev_;
		unique_fd coverage_srv_fd_;
		struct uuid uuid_;

trusty/coverage/include/trusty/coverage/record.h

0 → 100644

+70 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2020 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		/* This file needs to be kept in-sync with its counterpart on Trusty side:
		* trusty/user/base/lib/coverage/common/include/lib/coverage/common/record.h */

		#pragma once

		#include <stdint.h>

		/**
		* enum coverage_record_type - Coverage region header type
		* @COV_START: Magic header start marker
		* @COV_8BIT_COUNTERS: 8bit counter for each instrumentation point
		* @COV_INSTR_PCS: Pointer length offset of each instrumentation point from the
		* start of the binary
		* @COV_TOTAL_LENGTH: Total length of the entire coverage record, must be the
		* last header item.
		*
		* Describes the type of a region of the coverage record. See &struct
		* coverage_record_header.
		*/
		enum coverage_record_type {
		COV_START = 0x434f5652,
		COV_8BIT_COUNTERS = 1,
		COV_INSTR_PCS = 2,
		COV_TOTAL_LENGTH = 0,
		};

		/**
		* struct coverage_record_header - Header entry describing a region of the
		* coverage record.
		* @type: type of the region, must be one of @enum coverage_record_type
		* @offset: offset from the beginning of the header to the start of the region
		*
		* Coverage records start with a header which is a list of struct
		* coverage_record_header, beginning with an entry with type COV_START and
		* terminated with an entry with type COV_TOTAL_LENGTH. Each of these header
		* entries corresponds to a region of the record, with the offset indicating the
		* offset of the start of that region from the beginning of the record (i.e. the
		* beginning of the header). Each record type and offset is 32-bit field with
		* native endianness. The first header item must be COV_START with a 0 offset.
		* The COV_START entry should be initialized when the coverage header is
		* complete and ready for consumption by the client, because coverage record
		* initialization happens asynchronously. The final header item,
		* COV_TOTAL_LENGTH, which must always be present, indicates the total length of
		* the coverage record, including the header.
		*
		* Coverage regions should be contiguous, so the end of one region is the start
		* of the next, and the coverage header must be in the same order as the regions
		* in the record body. Thus we can compute the length of a region by subtracting
		* the region's offset from the offset of the next header item.
		*/
		struct coverage_record_header {
		uint32_t type;
		uint32_t offset;
		};