commit d2bd6c5f13bd4716c9bb9b0e00bb71d8b377dc82
author Christopher Ferris <cferris@google.com> Wed May 11 14:42:38 2022 -0700
committer Christopher Ferris <cferris@google.com> Wed May 11 15:39:20 2022 -0700
tree 09056f3f7ce0c592952fdfed67e40a5f63b08474
parent af4db6749ab44762d9662d260d230162237891ad

Use new AndroidUnwinder object.

Replace libbacktrace with the new AndroidUnwinder object.

Bug: 120606663

Test: Ran unit tests.
Test: Added call of UnwindMainThreadStack() in DebugRebootLogging()
Test: and verified unwind data is logged properly.
Change-Id: Ia724f9485377d6d2c894283242a3c5653bf82768

init/Android.bp

diff --git a/init/Android.bp b/init/Android.bp
index dd67d04..f91265e 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -178,7 +178,6 @@
         "update_metadata-protos",
     ],
     shared_libs: [
-        "libbacktrace",
         "libbase",
         "libbootloader_message",
         "libcrypto",
@@ -195,6 +194,7 @@
         "libprocessgroup",
         "libprocessgroup_setup",
         "libselinux",
+        "libunwindstack",
         "libutils",
         "libziparchive",
     ],
@@ -352,7 +352,6 @@
         "libgsi",
         "liblzma",
         "libunwindstack_no_dex",
-        "libbacktrace_no_dex",
         "libmodprobe",
         "libext2_uuid",
         "libprotobuf-cpp-lite",

init/init.cpp

diff --git a/init/init.cpp b/init/init.cpp
index 038f172..f8330bc 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -48,7 +48,6 @@
 #include <android-base/properties.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
-#include <backtrace/Backtrace.h>
 #include <fs_avb/fs_avb.h>
 #include <fs_mgr_vendor_overlay.h>
 #include <keyutils.h>
@@ -58,6 +57,7 @@
 #include <processgroup/processgroup.h>
 #include <processgroup/setup.h>
 #include <selinux/android.h>
+#include <unwindstack/AndroidUnwinder.h>
 
 #include "action_parser.h"
 #include "builtins.h"
@@ -253,12 +253,14 @@
 } shutdown_state;
 
 static void UnwindMainThreadStack() {
-    std::unique_ptr<Backtrace> backtrace(Backtrace::Create(BACKTRACE_CURRENT_PROCESS, 1));
-    if (!backtrace->Unwind(0)) {
-        LOG(ERROR) << __FUNCTION__ << "sys.powerctl: Failed to unwind callstack.";
+    unwindstack::AndroidLocalUnwinder unwinder;
+    unwindstack::AndroidUnwinderData data;
+    if (!unwinder.Unwind(data)) {
+        LOG(ERROR) << __FUNCTION__
+                   << "sys.powerctl: Failed to unwind callstack: " << data.GetErrorString();
     }
-    for (size_t i = 0; i < backtrace->NumFrames(); i++) {
-        LOG(ERROR) << "sys.powerctl: " << backtrace->FormatFrameData(i);
+    for (const auto& frame : data.frames) {
+        LOG(ERROR) << "sys.powerctl: " << unwinder.FormatFrame(frame);
     }
 }
 

init/reboot_utils.cpp

diff --git a/init/reboot_utils.cpp b/init/reboot_utils.cpp
index b3fa9fd..f8e1de0 100644
--- a/init/reboot_utils.cpp
+++ b/init/reboot_utils.cpp
@@ -26,8 +26,8 @@
 #include <android-base/logging.h>
 #include <android-base/properties.h>
 #include <android-base/strings.h>
-#include <backtrace/Backtrace.h>
 #include <cutils/android_reboot.h>
+#include <unwindstack/AndroidUnwinder.h>
 
 #include "capabilities.h"
 #include "reboot_utils.h"
@@ -157,13 +157,13 @@
 
     // In the parent, let's try to get a backtrace then shutdown.
     LOG(ERROR) << __FUNCTION__ << ": signal " << signal_number;
-    std::unique_ptr<Backtrace> backtrace(
-            Backtrace::Create(BACKTRACE_CURRENT_PROCESS, BACKTRACE_CURRENT_THREAD));
-    if (!backtrace->Unwind(0)) {
-        LOG(ERROR) << __FUNCTION__ << ": Failed to unwind callstack.";
+    unwindstack::AndroidLocalUnwinder unwinder;
+    unwindstack::AndroidUnwinderData data;
+    if (!unwinder.Unwind(data)) {
+        LOG(ERROR) << __FUNCTION__ << ": Failed to unwind callstack: " << data.GetErrorString();
     }
-    for (size_t i = 0; i < backtrace->NumFrames(); i++) {
-        LOG(ERROR) << backtrace->FormatFrameData(i);
+    for (const auto& frame : data.frames) {
+        LOG(ERROR) << unwinder.FormatFrame(frame);
     }
     if (init_fatal_panic) {
         LOG(ERROR) << __FUNCTION__ << ": Trigger crash";