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/map_info.c b/libbacktrace/map_info.c
new file mode 100644
index 0000000..9cc6e01
--- /dev/null
+++ b/libbacktrace/map_info.c
@@ -0,0 +1,173 @@
+/*
+ * 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.
+ */
+
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <cutils/log.h>
+#include <sys/time.h>
+
+#include <backtrace/backtrace.h>
+
+#if defined(__APPLE__)
+
+// Mac OS vmmap(1) output:
+// __TEXT 0009f000-000a1000 [ 8K 8K] r-x/rwx SM=COW /Volumes/android/dalvik-dev/out/host/darwin-x86/bin/libcorkscrew_test\n
+// 012345678901234567890123456789012345678901234567890123456789
+// 0 1 2 3 4 5
+static backtrace_map_info_t* parse_vmmap_line(const char* line) {
+ unsigned long int start;
+ unsigned long int end;
+ char permissions[4];
+ int name_pos;
+ if (sscanf(line, "%*21c %lx-%lx [%*13c] %3c/%*3c SM=%*3c %n",
+ &start, &end, permissions, &name_pos) != 3) {
+ return NULL;
+ }
+
+ const char* name = line + name_pos;
+ size_t name_len = strlen(name);
+
+ backtrace_map_info_t* mi = calloc(1, sizeof(backtrace_map_info_t) + name_len);
+ if (mi != NULL) {
+ mi->start = start;
+ mi->end = end;
+ mi->is_readable = permissions[0] == 'r';
+ mi->is_writable = permissions[1] == 'w';
+ mi->is_executable = permissions[2] == 'x';
+ memcpy(mi->name, name, name_len);
+ mi->name[name_len - 1] = '\0';
+ ALOGV("Parsed map: start=0x%08x, end=0x%08x, "
+ "is_readable=%d, is_writable=%d is_executable=%d, name=%s",
+ mi->start, mi->end,
+ mi->is_readable, mi->is_writable, mi->is_executable, mi->name);
+ }
+ return mi;
+}
+
+backtrace_map_info_t* backtrace_create_map_info_list(pid_t pid) {
+ char cmd[1024];
+ if (pid < 0) {
+ pid = getpid();
+ }
+ snprintf(cmd, sizeof(cmd), "vmmap -w -resident -submap -allSplitLibs -interleaved %d", pid);
+ FILE* fp = popen(cmd, "r");
+ if (fp == NULL) {
+ return NULL;
+ }
+
+ char line[1024];
+ backtrace_map_info_t* milist = NULL;
+ while (fgets(line, sizeof(line), fp) != NULL) {
+ backtrace_map_info_t* mi = parse_vmmap_line(line);
+ if (mi != NULL) {
+ mi->next = milist;
+ milist = mi;
+ }
+ }
+ pclose(fp);
+ return milist;
+}
+
+#else
+
+// Linux /proc/<pid>/maps lines:
+// 6f000000-6f01e000 rwxp 00000000 00:0c 16389419 /system/lib/libcomposer.so\n
+// 012345678901234567890123456789012345678901234567890123456789
+// 0 1 2 3 4 5
+static backtrace_map_info_t* parse_maps_line(const char* line)
+{
+ unsigned long int start;
+ unsigned long int end;
+ char permissions[5];
+ int name_pos;
+ if (sscanf(line, "%lx-%lx %4s %*x %*x:%*x %*d%n", &start, &end,
+ permissions, &name_pos) != 3) {
+ return NULL;
+ }
+
+ while (isspace(line[name_pos])) {
+ name_pos += 1;
+ }
+ const char* name = line + name_pos;
+ size_t name_len = strlen(name);
+ if (name_len && name[name_len - 1] == '\n') {
+ name_len -= 1;
+ }
+
+ backtrace_map_info_t* mi = calloc(1, sizeof(backtrace_map_info_t) + name_len + 1);
+ if (mi) {
+ mi->start = start;
+ mi->end = end;
+ mi->is_readable = strlen(permissions) == 4 && permissions[0] == 'r';
+ mi->is_writable = strlen(permissions) == 4 && permissions[1] == 'w';
+ mi->is_executable = strlen(permissions) == 4 && permissions[2] == 'x';
+ memcpy(mi->name, name, name_len);
+ mi->name[name_len] = '\0';
+ ALOGV("Parsed map: start=0x%08x, end=0x%08x, "
+ "is_readable=%d, is_writable=%d, is_executable=%d, name=%s",
+ mi->start, mi->end,
+ mi->is_readable, mi->is_writable, mi->is_executable, mi->name);
+ }
+ return mi;
+}
+
+backtrace_map_info_t* backtrace_create_map_info_list(pid_t tid) {
+ char path[PATH_MAX];
+ char line[1024];
+ FILE* fp;
+ backtrace_map_info_t* milist = NULL;
+
+ if (tid < 0) {
+ tid = getpid();
+ }
+ snprintf(path, PATH_MAX, "/proc/%d/maps", tid);
+ fp = fopen(path, "r");
+ if (fp) {
+ while(fgets(line, sizeof(line), fp)) {
+ backtrace_map_info_t* mi = parse_maps_line(line);
+ if (mi) {
+ mi->next = milist;
+ milist = mi;
+ }
+ }
+ fclose(fp);
+ }
+ return milist;
+}
+
+#endif
+
+void backtrace_destroy_map_info_list(backtrace_map_info_t* milist) {
+ while (milist) {
+ backtrace_map_info_t* next = milist->next;
+ free(milist);
+ milist = next;
+ }
+}
+
+const backtrace_map_info_t* backtrace_find_map_info(
+ const backtrace_map_info_t* milist, uintptr_t addr) {
+ const backtrace_map_info_t* mi = milist;
+ while (mi && !(addr >= mi->start && addr < mi->end)) {
+ mi = mi->next;
+ }
+ return mi;
+}