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/corkscrew.c b/libbacktrace/corkscrew.c
new file mode 100644
index 0000000..899409a
--- /dev/null
+++ b/libbacktrace/corkscrew.c
@@ -0,0 +1,130 @@
+/*
+ * 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 <string.h>
+
+#include <cutils/log.h>
+#include <backtrace/backtrace.h>
+
+#include <corkscrew/backtrace.h>
+
+#define __USE_GNU
+#include <dlfcn.h>
+
+#include "common.h"
+#include "demangle.h"
+
+bool backtrace_get_data(backtrace_t* backtrace, pid_t tid) {
+ backtrace->num_frames = 0;
+ backtrace->tid = tid;
+ backtrace->private_data = NULL;
+ backtrace->map_info_list = backtrace_create_map_info_list(tid);
+
+ backtrace_frame_t frames[MAX_BACKTRACE_FRAMES];
+ ssize_t num_frames;
+ if (tid < 0) {
+ // Get data for the current thread.
+ num_frames = unwind_backtrace(frames, 0, MAX_BACKTRACE_FRAMES);
+ } else {
+ // Get data for a different thread.
+ ptrace_context_t* ptrace_context = load_ptrace_context(tid);
+ backtrace->private_data = ptrace_context;
+
+ num_frames = unwind_backtrace_ptrace(
+ tid, ptrace_context, frames, 0, MAX_BACKTRACE_FRAMES);
+ }
+ if (num_frames < 0) {
+ ALOGW("backtrace_get_data: unwind_backtrace_ptrace failed %d\n",
+ num_frames);
+ backtrace_free_data(backtrace);
+ return false;
+ }
+
+ backtrace->num_frames = num_frames;
+ backtrace_frame_data_t* frame;
+ uintptr_t map_start;
+ for (size_t i = 0; i < backtrace->num_frames; i++) {
+ frame = &backtrace->frames[i];
+ frame->pc = frames[i].absolute_pc;
+ frame->sp = frames[i].stack_top;
+ frame->stack_size = frames[i].stack_size;
+
+ frame->map_offset = 0;
+ frame->map_name = backtrace_get_map_info(backtrace, frame->pc, &map_start);
+ if (frame->map_name) {
+ frame->map_offset = frame->pc - map_start;
+ }
+
+ frame->proc_offset = 0;
+ frame->proc_name = backtrace_get_proc_name(backtrace, frame->pc, &frame->proc_offset);
+ }
+
+ return true;
+}
+
+void backtrace_free_data(backtrace_t* backtrace) {
+ free_frame_data(backtrace);
+
+ if (backtrace->map_info_list) {
+ backtrace_destroy_map_info_list(backtrace->map_info_list);
+ backtrace->map_info_list = NULL;
+ }
+
+ if (backtrace->private_data) {
+ ptrace_context_t* ptrace_context = (ptrace_context_t*)backtrace->private_data;
+ free_ptrace_context(ptrace_context);
+ backtrace->private_data = NULL;
+ }
+}
+
+char* backtrace_get_proc_name(const backtrace_t* backtrace, uintptr_t pc,
+ uintptr_t* offset) {
+ const char* symbol_name = NULL;
+ *offset = 0;
+ if (backtrace->tid < 0) {
+ // Get information about the current thread.
+ Dl_info info;
+ const backtrace_map_info_t* map_info;
+ map_info = backtrace_find_map_info(backtrace->map_info_list, pc);
+ if (map_info && dladdr((const void*)pc, &info) && info.dli_sname) {
+ *offset = pc - map_info->start - (uintptr_t)info.dli_saddr + (uintptr_t)info.dli_fbase;
+ symbol_name = info.dli_sname;
+ }
+ } else {
+ // Get information about a different thread.
+ ptrace_context_t* ptrace_context = (ptrace_context_t*)backtrace->private_data;
+ const map_info_t* map_info;
+ const symbol_t* symbol;
+ find_symbol_ptrace(ptrace_context, pc, &map_info, &symbol);
+ if (symbol) {
+ if (map_info) {
+ *offset = pc - map_info->start - symbol->start;
+ }
+ symbol_name = symbol->name;
+ }
+ }
+
+ char* name = NULL;
+ if (symbol_name) {
+ name = demangle_symbol_name(symbol_name);
+ if (!name) {
+ name = strdup(symbol_name);
+ }
+ }
+ return name;
+}