Create a single backtrace library.
This library will be used to abstract away getting backtrace
data from how it is implemented. This is the first step to
replacing libcorkscrew with libunwind.
Bug: 8410085
Change-Id: Ie8f159e96a055d378e1ddc72d40239fba4cf52b7
diff --git a/libbacktrace/unwind_remote.c b/libbacktrace/unwind_remote.c
new file mode 100644
index 0000000..ebbde2e
--- /dev/null
+++ b/libbacktrace/unwind_remote.c
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#define LOG_TAG "libbacktrace"
+
+#include <sys/ptrace.h>
+#include <string.h>
+
+#include <cutils/log.h>
+#include <backtrace/backtrace.h>
+
+#include <libunwind.h>
+#include <libunwind-ptrace.h>
+
+#include "common.h"
+#include "demangle.h"
+
+typedef struct {
+ unw_addr_space_t addr_space;
+ struct UPT_info* upt_info;
+} backtrace_private_t;
+
+static bool remote_get_frames(backtrace_t* backtrace) {
+ backtrace_private_t* data = (backtrace_private_t*)backtrace->private_data;
+ unw_cursor_t cursor;
+ int ret = unw_init_remote(&cursor, data->addr_space, data->upt_info);
+ if (ret < 0) {
+ ALOGW("remote_get_frames: unw_init_remote failed %d\n", ret);
+ return false;
+ }
+
+ backtrace_frame_data_t* frame;
+ bool returnValue = true;
+ backtrace->num_frames = 0;
+ uintptr_t map_start;
+ do {
+ frame = &backtrace->frames[backtrace->num_frames];
+ frame->stack_size = 0;
+ frame->map_name = NULL;
+ frame->map_offset = 0;
+ frame->proc_name = NULL;
+ frame->proc_offset = 0;
+
+ ret = unw_get_reg(&cursor, UNW_REG_IP, &frame->pc);
+ if (ret < 0) {
+ ALOGW("remote_get_frames: Failed to read IP %d\n", ret);
+ returnValue = false;
+ break;
+ }
+ ret = unw_get_reg(&cursor, UNW_REG_SP, &frame->sp);
+ if (ret < 0) {
+ ALOGW("remote_get_frames: Failed to read SP %d\n", ret);
+ returnValue = false;
+ break;
+ }
+ if (backtrace->num_frames) {
+ backtrace_frame_data_t* prev = &backtrace->frames[backtrace->num_frames-1];
+ prev->stack_size = frame->sp - prev->sp;
+ }
+
+ frame->proc_name = backtrace_get_proc_name(backtrace, frame->pc, &frame->proc_offset);
+
+ frame->map_name = backtrace_get_map_info(backtrace, frame->pc, &map_start);
+ if (frame->map_name) {
+ frame->map_offset = frame->pc - map_start;
+ }
+
+ backtrace->num_frames++;
+ ret = unw_step (&cursor);
+ } while (ret > 0 && backtrace->num_frames < MAX_BACKTRACE_FRAMES);
+
+ return returnValue;
+}
+
+bool remote_get_data(backtrace_t* backtrace) {
+ backtrace_private_t* data = (backtrace_private_t*)malloc(sizeof(backtrace_private_t));
+ if (!data) {
+ ALOGW("remote_get_data: Failed to allocate memory.\n");
+ backtrace_free_data(backtrace);
+ return false;
+ }
+ data->addr_space = NULL;
+ data->upt_info = NULL;
+
+ backtrace->private_data = data;
+ data->addr_space = unw_create_addr_space(&_UPT_accessors, 0);
+ if (!data->addr_space) {
+ ALOGW("remote_get_data: Failed to create unw address space.\n");
+ backtrace_free_data(backtrace);
+ return false;
+ }
+
+ data->upt_info = _UPT_create(backtrace->tid);
+ if (!data->upt_info) {
+ ALOGW("remote_get_data: Failed to create upt info.\n");
+ backtrace_free_data(backtrace);
+ return false;
+ }
+
+ if (!remote_get_frames(backtrace)) {
+ backtrace_free_data(backtrace);
+ return false;
+ }
+
+ return true;
+}
+
+void remote_free_data(backtrace_t* backtrace) {
+ if (backtrace->private_data) {
+ backtrace_private_t* data = (backtrace_private_t*)backtrace->private_data;
+ if (data->upt_info) {
+ _UPT_destroy(data->upt_info);
+ data->upt_info = NULL;
+ }
+ if (data->addr_space) {
+ unw_destroy_addr_space(data->addr_space);
+ }
+
+ free(backtrace->private_data);
+ backtrace->private_data = NULL;
+ }
+}
+
+char* remote_get_proc_name(const backtrace_t* backtrace, uintptr_t pc,
+ uintptr_t* offset) {
+ backtrace_private_t* data = (backtrace_private_t*)backtrace->private_data;
+ char buf[512];
+
+ if (unw_get_proc_name_by_ip(data->addr_space, pc, buf, sizeof(buf), offset,
+ data->upt_info) >= 0 && buf[0] != '\0') {
+ char* symbol = demangle_symbol_name(buf);
+ if (!symbol) {
+ symbol = strdup(buf);
+ }
+ return symbol;
+ }
+ return NULL;
+}