Replace libbacktrace with libunwindstack directly.
Small modifications to the dump_stack method and added unit tests to
verify the output.
Bug: 120606663
Test: Unit tests pass, debuggerd run on processes on target.
Change-Id: Id385a915b751abda3dd6baebed6c3ce498c3bf6e
diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index b20014f..8798ad3 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -41,19 +41,20 @@
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include <android/log.h>
-#include <backtrace/Backtrace.h>
-#include <backtrace/BacktraceMap.h>
#include <log/log.h>
#include <log/logprint.h>
#include <private/android_filesystem_config.h>
+#include <unwindstack/DexFiles.h>
+#include <unwindstack/JitDebug.h>
+#include <unwindstack/Maps.h>
#include <unwindstack/Memory.h>
#include <unwindstack/Regs.h>
+#include <unwindstack/Unwinder.h>
// Needed to get DEBUGGER_SIGNAL.
#include "debuggerd/handler.h"
#include "libdebuggerd/backtrace.h"
-#include "libdebuggerd/elf_utils.h"
#include "libdebuggerd/open_files_list.h"
#include "libdebuggerd/utility.h"
@@ -62,9 +63,6 @@
using android::base::StringPrintf;
using android::base::unique_fd;
-using unwindstack::Memory;
-using unwindstack::Regs;
-
using namespace std::literals::string_literals;
#define STACK_WORDS 16
@@ -87,7 +85,7 @@
_LOG(log, logtype::HEADER, "Timestamp: %s\n", buf);
}
-static void dump_probable_cause(log_t* log, const siginfo_t* si, BacktraceMap* map) {
+static void dump_probable_cause(log_t* log, const siginfo_t* si, unwindstack::Maps* maps) {
std::string cause;
if (si->si_signo == SIGSEGV && si->si_code == SEGV_MAPERR) {
if (si->si_addr < reinterpret_cast<void*>(4096)) {
@@ -104,12 +102,9 @@
cause = "call to kuser_cmpxchg64";
}
} else if (si->si_signo == SIGSEGV && si->si_code == SEGV_ACCERR) {
- for (auto it = map->begin(); it != map->end(); ++it) {
- const backtrace_map_t* entry = *it;
- if (si->si_addr >= reinterpret_cast<void*>(entry->start) &&
- si->si_addr < reinterpret_cast<void*>(entry->end) && entry->flags == PROT_EXEC) {
- cause = "execute-only (no-read) memory access error; likely due to data in .text.";
- }
+ unwindstack::MapInfo* map_info = maps->Find(reinterpret_cast<uint64_t>(si->si_addr));
+ if (map_info != nullptr && map_info->flags == PROT_EXEC) {
+ cause = "execute-only (no-read) memory access error; likely due to data in .text.";
}
} else if (si->si_signo == SIGSYS && si->si_code == SYS_SECCOMP) {
cause = StringPrintf("seccomp prevented call to disallowed %s system call %d", ABI_STRING,
@@ -119,7 +114,8 @@
if (!cause.empty()) _LOG(log, logtype::HEADER, "Cause: %s\n", cause.c_str());
}
-static void dump_signal_info(log_t* log, const ThreadInfo& thread_info, Memory* process_memory) {
+static void dump_signal_info(log_t* log, const ThreadInfo& thread_info,
+ unwindstack::Memory* process_memory) {
char addr_desc[64]; // ", fault addr 0x1234"
if (signal_has_si_addr(thread_info.siginfo)) {
void* addr = thread_info.siginfo->si_addr;
@@ -156,14 +152,14 @@
thread_info.tid, thread_info.thread_name.c_str(), thread_info.process_name.c_str());
}
-static void dump_stack_segment(log_t* log, BacktraceMap* backtrace_map, Memory* process_memory,
+static void dump_stack_segment(log_t* log, unwindstack::Maps* maps, unwindstack::Memory* memory,
uint64_t* sp, size_t words, int label) {
// Read the data all at once.
word_t stack_data[words];
// TODO: Do we need to word align this for crashes caused by a misaligned sp?
// The process_vm_readv implementation of Memory should handle this appropriately?
- size_t bytes_read = process_memory->Read(*sp, stack_data, sizeof(word_t) * words);
+ size_t bytes_read = memory->Read(*sp, stack_data, sizeof(word_t) * words);
words = bytes_read / sizeof(word_t);
std::string line;
for (size_t i = 0; i < words; i++) {
@@ -176,17 +172,15 @@
}
line += StringPrintf("%" PRIPTR " %" PRIPTR, *sp, static_cast<uint64_t>(stack_data[i]));
- backtrace_map_t map;
- backtrace_map->FillIn(stack_data[i], &map);
- std::string map_name{map.Name()};
- if (BacktraceMap::IsValid(map) && !map_name.empty()) {
- line += " " + map_name;
- uint64_t offset = 0;
- std::string func_name = backtrace_map->GetFunctionName(stack_data[i], &offset);
- if (!func_name.empty()) {
+ unwindstack::MapInfo* map_info = maps->Find(stack_data[i]);
+ if (map_info != nullptr && !map_info->name.empty()) {
+ line += " " + map_info->name;
+ std::string func_name;
+ uint64_t func_offset = 0;
+ if (map_info->GetFunctionName(stack_data[i], &func_name, &func_offset)) {
line += " (" + func_name;
- if (offset) {
- line += StringPrintf("+%" PRIu64, offset);
+ if (func_offset) {
+ line += StringPrintf("+%" PRIu64, func_offset);
}
line += ')';
}
@@ -197,12 +191,11 @@
}
}
-static void dump_stack(log_t* log, BacktraceMap* backtrace_map, Memory* process_memory,
- std::vector<backtrace_frame_data_t>& frames) {
+static void dump_stack(log_t* log, const std::vector<unwindstack::FrameData>& frames,
+ unwindstack::Maps* maps, unwindstack::Memory* memory) {
size_t first = 0, last;
for (size_t i = 0; i < frames.size(); i++) {
- const backtrace_frame_data_t& frame = frames[i];
- if (frame.sp) {
+ if (frames[i].sp) {
if (!first) {
first = i+1;
}
@@ -217,29 +210,44 @@
// Dump a few words before the first frame.
uint64_t sp = frames[first].sp - STACK_WORDS * sizeof(word_t);
- dump_stack_segment(log, backtrace_map, process_memory, &sp, STACK_WORDS, -1);
+ dump_stack_segment(log, maps, memory, &sp, STACK_WORDS, -1);
+
+#if defined(__LP64__)
+ static constexpr const char delimiter[] = " ................ ................\n";
+#else
+ static constexpr const char delimiter[] = " ........ ........\n";
+#endif
// Dump a few words from all successive frames.
- // Only log the first 3 frames, put the rest in the tombstone.
for (size_t i = first; i <= last; i++) {
- const backtrace_frame_data_t* frame = &frames[i];
+ auto* frame = &frames[i];
if (sp != frame->sp) {
- _LOG(log, logtype::STACK, " ........ ........\n");
+ _LOG(log, logtype::STACK, delimiter);
sp = frame->sp;
}
- if (i == last) {
- dump_stack_segment(log, backtrace_map, process_memory, &sp, STACK_WORDS, i);
- if (sp < frame->sp + frame->stack_size) {
- _LOG(log, logtype::STACK, " ........ ........\n");
- }
- } else {
- size_t words = frame->stack_size / sizeof(word_t);
- if (words == 0) {
- words = 1;
- } else if (words > STACK_WORDS) {
+ if (i != last) {
+ // Print stack data up to the stack from the next frame.
+ size_t words;
+ uint64_t next_sp = frames[i + 1].sp;
+ if (next_sp < sp) {
+ // The next frame is probably using a completely different stack,
+ // so dump the max from this stack.
words = STACK_WORDS;
+ } else {
+ words = (next_sp - sp) / sizeof(word_t);
+ if (words == 0) {
+ // The sp is the same as the next frame, print at least
+ // one line for this frame.
+ words = 1;
+ } else if (words > STACK_WORDS) {
+ words = STACK_WORDS;
+ }
}
- dump_stack_segment(log, backtrace_map, process_memory, &sp, words, i);
+ dump_stack_segment(log, maps, memory, &sp, words, i);
+ } else {
+ // Print some number of words past the last stack frame since we
+ // don't know how large the stack is.
+ dump_stack_segment(log, maps, memory, &sp, STACK_WORDS, i);
}
}
}
@@ -256,7 +264,7 @@
return addr_str;
}
-static void dump_abort_message(log_t* log, Memory* process_memory, uint64_t address) {
+static void dump_abort_message(log_t* log, unwindstack::Memory* process_memory, uint64_t address) {
if (address == 0) {
return;
}
@@ -285,16 +293,16 @@
_LOG(log, logtype::HEADER, "Abort message: '%s'\n", &msg[0]);
}
-static void dump_all_maps(log_t* log, BacktraceMap* map, Memory* process_memory, uint64_t addr) {
+static void dump_all_maps(log_t* log, unwindstack::Unwinder* unwinder, uint64_t addr) {
bool print_fault_address_marker = addr;
- ScopedBacktraceMapIteratorLock lock(map);
+ unwindstack::Maps* maps = unwinder->GetMaps();
_LOG(log, logtype::MAPS,
"\n"
"memory map (%zu entr%s):",
- map->size(), map->size() == 1 ? "y" : "ies");
+ maps->Total(), maps->Total() == 1 ? "y" : "ies");
if (print_fault_address_marker) {
- if (map->begin() != map->end() && addr < (*map->begin())->start) {
+ if (maps->Total() != 0 && addr < maps->Get(0)->start) {
_LOG(log, logtype::MAPS, "\n--->Fault address falls at %s before any mapped regions\n",
get_addr_string(addr).c_str());
print_fault_address_marker = false;
@@ -305,51 +313,54 @@
_LOG(log, logtype::MAPS, "\n");
}
+ std::shared_ptr<unwindstack::Memory>& process_memory = unwinder->GetProcessMemory();
+
std::string line;
- for (auto it = map->begin(); it != map->end(); ++it) {
- const backtrace_map_t* entry = *it;
+ for (unwindstack::MapInfo* map_info : *maps) {
line = " ";
if (print_fault_address_marker) {
- if (addr < entry->start) {
+ if (addr < map_info->start) {
_LOG(log, logtype::MAPS, "--->Fault address falls at %s between mapped regions\n",
get_addr_string(addr).c_str());
print_fault_address_marker = false;
- } else if (addr >= entry->start && addr < entry->end) {
+ } else if (addr >= map_info->start && addr < map_info->end) {
line = "--->";
print_fault_address_marker = false;
}
}
- line += get_addr_string(entry->start) + '-' + get_addr_string(entry->end - 1) + ' ';
- if (entry->flags & PROT_READ) {
+ line += get_addr_string(map_info->start) + '-' + get_addr_string(map_info->end - 1) + ' ';
+ if (map_info->flags & PROT_READ) {
line += 'r';
} else {
line += '-';
}
- if (entry->flags & PROT_WRITE) {
+ if (map_info->flags & PROT_WRITE) {
line += 'w';
} else {
line += '-';
}
- if (entry->flags & PROT_EXEC) {
+ if (map_info->flags & PROT_EXEC) {
line += 'x';
} else {
line += '-';
}
- line += StringPrintf(" %8" PRIx64 " %8" PRIx64, entry->offset, entry->end - entry->start);
+ line += StringPrintf(" %8" PRIx64 " %8" PRIx64, map_info->offset,
+ map_info->end - map_info->start);
bool space_needed = true;
- if (entry->name.length() > 0) {
+ if (!map_info->name.empty()) {
space_needed = false;
- line += " " + entry->name;
- std::string build_id;
- if ((entry->flags & PROT_READ) && elf_get_build_id(process_memory, entry->start, &build_id)) {
+ line += " " + map_info->name;
+ std::string build_id = map_info->GetPrintableBuildID();
+ if (!build_id.empty()) {
line += " (BuildId: " + build_id + ")";
}
}
- if (entry->load_bias != 0) {
+ uint64_t load_bias = map_info->GetLoadBias(process_memory);
+ if (load_bias != 0) {
if (space_needed) {
line += ' ';
}
- line += StringPrintf(" (load bias 0x%" PRIx64 ")", entry->load_bias);
+ line += StringPrintf(" (load bias 0x%" PRIx64 ")", load_bias);
}
_LOG(log, logtype::MAPS, "%s\n", line.c_str());
}
@@ -359,9 +370,9 @@
}
}
-void dump_backtrace(log_t* log, std::vector<backtrace_frame_data_t>& frames, const char* prefix) {
- for (auto& frame : frames) {
- _LOG(log, logtype::BACKTRACE, "%s%s\n", prefix, Backtrace::FormatFrameData(&frame).c_str());
+void dump_backtrace(log_t* log, unwindstack::Unwinder* unwinder, const char* prefix) {
+ for (size_t i = 0; i < unwinder->NumFrames(); i++) {
+ _LOG(log, logtype::BACKTRACE, "%s%s\n", prefix, unwinder->FormatFrame(i).c_str());
}
}
@@ -377,7 +388,7 @@
_LOG(log, logtype::REGISTERS, " %s\n", output.c_str());
}
-void dump_registers(log_t* log, Regs* regs) {
+void dump_registers(log_t* log, unwindstack::Regs* regs) {
// Split lr/sp/pc into their own special row.
static constexpr size_t column_count = 4;
std::vector<std::pair<std::string, uint64_t>> current_row;
@@ -416,23 +427,22 @@
print_register_row(log, special_row);
}
-void dump_memory_and_code(log_t* log, BacktraceMap* map, Memory* memory, Regs* regs) {
- regs->IterateRegisters([log, map, memory](const char* reg_name, uint64_t reg_value) {
+void dump_memory_and_code(log_t* log, unwindstack::Maps* maps, unwindstack::Memory* memory,
+ unwindstack::Regs* regs) {
+ regs->IterateRegisters([log, maps, memory](const char* reg_name, uint64_t reg_value) {
std::string label{"memory near "s + reg_name};
- if (map) {
- backtrace_map_t map_info;
- map->FillIn(reg_value, &map_info);
- std::string map_name{map_info.Name()};
- if (!map_name.empty()) label += " (" + map_info.Name() + ")";
+ if (maps) {
+ unwindstack::MapInfo* map_info = maps->Find(reg_value);
+ if (map_info != nullptr && !map_info->name.empty()) {
+ label += " (" + map_info->name + ")";
+ }
}
dump_memory(log, memory, reg_value, label);
});
}
-static bool dump_thread(log_t* log, BacktraceMap* map, Memory* process_memory,
- const ThreadInfo& thread_info, uint64_t abort_msg_address,
- bool primary_thread) {
- UNUSED(process_memory);
+static bool dump_thread(log_t* log, unwindstack::Unwinder* unwinder, const ThreadInfo& thread_info,
+ uint64_t abort_msg_address, bool primary_thread) {
log->current_tid = thread_info.tid;
if (!primary_thread) {
_LOG(log, logtype::THREAD, "--- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---\n");
@@ -440,41 +450,41 @@
dump_thread_info(log, thread_info);
if (thread_info.siginfo) {
- dump_signal_info(log, thread_info, process_memory);
- dump_probable_cause(log, thread_info.siginfo, map);
+ dump_signal_info(log, thread_info, unwinder->GetProcessMemory().get());
+ dump_probable_cause(log, thread_info.siginfo, unwinder->GetMaps());
}
if (primary_thread) {
- dump_abort_message(log, process_memory, abort_msg_address);
+ dump_abort_message(log, unwinder->GetProcessMemory().get(), abort_msg_address);
}
dump_registers(log, thread_info.registers.get());
// Unwind will mutate the registers, so make a copy first.
- std::unique_ptr<Regs> regs_copy(thread_info.registers->Clone());
- std::vector<backtrace_frame_data_t> frames;
- if (!Backtrace::Unwind(regs_copy.get(), map, &frames, 0, nullptr)) {
+ std::unique_ptr<unwindstack::Regs> regs_copy(thread_info.registers->Clone());
+ unwinder->SetRegs(regs_copy.get());
+ unwinder->Unwind();
+ if (unwinder->NumFrames() == 0) {
_LOG(log, logtype::THREAD, "Failed to unwind");
- return false;
- }
-
- if (!frames.empty()) {
+ } else {
_LOG(log, logtype::BACKTRACE, "\nbacktrace:\n");
- dump_backtrace(log, frames, " ");
+ dump_backtrace(log, unwinder, " ");
_LOG(log, logtype::STACK, "\nstack:\n");
- dump_stack(log, map, process_memory, frames);
+ dump_stack(log, unwinder->frames(), unwinder->GetMaps(), unwinder->GetProcessMemory().get());
}
if (primary_thread) {
- dump_memory_and_code(log, map, process_memory, thread_info.registers.get());
- if (map) {
+ unwindstack::Maps* maps = unwinder->GetMaps();
+ dump_memory_and_code(log, maps, unwinder->GetProcessMemory().get(),
+ thread_info.registers.get());
+ if (maps != nullptr) {
uint64_t addr = 0;
siginfo_t* si = thread_info.siginfo;
if (signal_has_si_addr(si)) {
addr = reinterpret_cast<uint64_t>(si->si_addr);
}
- dump_all_maps(log, map, process_memory, addr);
+ dump_all_maps(log, unwinder, addr);
}
}
@@ -625,7 +635,8 @@
read_with_default("/proc/self/comm", thread_name, sizeof(thread_name), "<unknown>");
read_with_default("/proc/self/cmdline", process_name, sizeof(process_name), "<unknown>");
- std::unique_ptr<Regs> regs(Regs::CreateFromUcontext(Regs::CurrentArch(), ucontext));
+ std::unique_ptr<unwindstack::Regs> regs(
+ unwindstack::Regs::CreateFromUcontext(unwindstack::Regs::CurrentArch(), ucontext));
std::map<pid_t, ThreadInfo> threads;
threads[gettid()] = ThreadInfo{
@@ -637,18 +648,16 @@
.siginfo = siginfo,
};
- std::unique_ptr<BacktraceMap> backtrace_map(BacktraceMap::Create(getpid(), false));
- if (!backtrace_map) {
- ALOGE("failed to create backtrace map");
- _exit(1);
+ unwindstack::UnwinderFromPid unwinder(kMaxFrames, pid);
+ if (!unwinder.Init(unwindstack::Regs::CurrentArch())) {
+ LOG(FATAL) << "Failed to init unwinder object.";
}
- std::shared_ptr<Memory> process_memory = backtrace_map->GetProcessMemory();
- engrave_tombstone(unique_fd(dup(tombstone_fd)), backtrace_map.get(), process_memory.get(),
- threads, tid, abort_msg_address, nullptr, nullptr);
+ engrave_tombstone(unique_fd(dup(tombstone_fd)), &unwinder, threads, tid, abort_msg_address,
+ nullptr, nullptr);
}
-void engrave_tombstone(unique_fd output_fd, BacktraceMap* map, Memory* process_memory,
+void engrave_tombstone(unique_fd output_fd, unwindstack::Unwinder* unwinder,
const std::map<pid_t, ThreadInfo>& threads, pid_t target_thread,
uint64_t abort_msg_address, OpenFilesList* open_files,
std::string* amfd_data) {
@@ -669,7 +678,7 @@
if (it == threads.end()) {
LOG(FATAL) << "failed to find target thread";
}
- dump_thread(&log, map, process_memory, it->second, abort_msg_address, true);
+ dump_thread(&log, unwinder, it->second, abort_msg_address, true);
if (want_logs) {
dump_logs(&log, it->second.pid, 50);
@@ -680,7 +689,7 @@
continue;
}
- dump_thread(&log, map, process_memory, thread_info, 0, false);
+ dump_thread(&log, unwinder, thread_info, 0, false);
}
if (open_files) {