1 files changed, 279 insertions, 0 deletions
diff --git a/trusty/coverage/coverage.cpp b/trusty/coverage/coverage.cpp
new file mode 100644
index 000000000..f383dd14a
--- /dev/null
+++ b/trusty/coverage/coverage.cpp
@@ -0,0 +1,279 @@
+/*
+ * Copyright (C) 2020 The Android Open Sourete 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.
+ */
+
+#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>
+
+#define COVERAGE_CLIENT_PORT "com.android.trusty.coverage.client"
+
+namespace android {
+namespace trusty {
+namespace coverage {
+
+using android::base::ErrnoError;
+using android::base::Error;
+using std::string;
+
+static inline uintptr_t RoundPageUp(uintptr_t val) {
+    return (val + (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
+}
+
+CoverageRecord::CoverageRecord(string tipc_dev, struct uuid* uuid)
+    : tipc_dev_(std::move(tipc_dev)),
+      coverage_srv_fd_(-1),
+      uuid_(*uuid),
+      record_len_(0),
+      shm_(NULL),
+      shm_len_(0) {}
+
+CoverageRecord::~CoverageRecord() {
+    if (shm_) {
+        munmap((void*)shm_, shm_len_);
+    }
+}
+
+Result<void> CoverageRecord::Rpc(coverage_client_req* req, int req_fd, coverage_client_resp* resp) {
+    int rc;
+
+    if (req_fd < 0) {
+        rc = write(coverage_srv_fd_, req, sizeof(*req));
+    } else {
+        iovec iov = {
+                .iov_base = req,
+                .iov_len = sizeof(*req),
+        };
+
+        trusty_shm shm = {
+                .fd = req_fd,
+                .transfer = TRUSTY_SHARE,
+        };
+
+        rc = tipc_send(coverage_srv_fd_, &iov, 1, &shm, 1);
+    }
+
+    if (rc != (int)sizeof(*req)) {
+        return ErrnoError() << "failed to send request to coverage server: ";
+    }
+
+    rc = read(coverage_srv_fd_, resp, sizeof(*resp));
+    if (rc != (int)sizeof(*resp)) {
+        return ErrnoError() << "failed to read reply from coverage server: ";
+    }
+
+    if (resp->hdr.cmd != (req->hdr.cmd | COVERAGE_CLIENT_CMD_RESP_BIT)) {
+        return ErrnoError() << "unknown response cmd: " << resp->hdr.cmd;
+    }
+
+    return {};
+}
+
+Result<void> CoverageRecord::Open() {
+    coverage_client_req req;
+    coverage_client_resp resp;
+
+    if (shm_) {
+        return {}; /* already initialized */
+    }
+
+    int fd = tipc_connect(tipc_dev_.c_str(), COVERAGE_CLIENT_PORT);
+    if (fd < 0) {
+        return ErrnoError() << "failed to connect to Trusty coverarge server: ";
+    }
+    coverage_srv_fd_.reset(fd);
+
+    req.hdr.cmd = COVERAGE_CLIENT_CMD_OPEN;
+    req.open_args.uuid = uuid_;
+    auto ret = Rpc(&req, -1, &resp);
+    if (!ret.ok()) {
+        return Error() << "failed to open coverage client: ";
+    }
+    record_len_ = resp.open_args.record_len;
+    shm_len_ = RoundPageUp(record_len_);
+
+    fd = memfd_create("trusty-coverage", 0);
+    if (fd < 0) {
+        return ErrnoError() << "failed to create memfd: ";
+    }
+    unique_fd memfd(fd);
+
+    if (ftruncate(memfd, shm_len_) < 0) {
+        return ErrnoError() << "failed to resize memfd: ";
+    }
+
+    void* shm = mmap(0, shm_len_, PROT_READ | PROT_WRITE, MAP_SHARED, memfd, 0);
+    if (shm == MAP_FAILED) {
+        return ErrnoError() << "failed to map memfd: ";
+    }
+
+    req.hdr.cmd = COVERAGE_CLIENT_CMD_SHARE_RECORD;
+    req.share_record_args.shm_len = shm_len_;
+    ret = Rpc(&req, memfd, &resp);
+    if (!ret.ok()) {
+        return Error() << "failed to send shared memory: ";
+    }
+
+    shm_ = shm;
+    return {};
+}
+
+void CoverageRecord::ResetFullRecord() {
+    auto header_region = GetRegionBounds(COV_START);
+    if (!header_region.ok()) {
+        // 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_);
+
+    *begin = shm_;
+    *end = (uint8_t*)(*begin) + record_len_;
+}
+
+void CoverageRecord::GetRawCounts(volatile uint8_t** begin, volatile uint8_t** end) {
+    auto region = GetRegionBounds(COV_8BIT_COUNTERS);
+    if (!region.ok()) {
+        *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.ok()) {
+        *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;
+
+    volatile uint8_t* begin = NULL;
+    volatile uint8_t* end = NULL;
+
+    GetRawCounts(&begin, &end);
+
+    for (volatile uint8_t* x = begin; x < end; x++) {
+        counter += *x;
+    }
+
+    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