/*
* Copyright (C) 2015 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 "OfflineUnwinder.h"
#include <sys/mman.h>
#include <android-base/logging.h>
#include <unwindstack/MachineArm.h>
#include <unwindstack/MachineArm64.h>
#include <unwindstack/MachineX86.h>
#include <unwindstack/MachineX86_64.h>
#include <unwindstack/Maps.h>
#include <unwindstack/Regs.h>
#include <unwindstack/RegsArm.h>
#include <unwindstack/RegsArm64.h>
#include <unwindstack/RegsX86.h>
#include <unwindstack/RegsX86_64.h>
#include <unwindstack/Unwinder.h>
#include <unwindstack/UserArm.h>
#include <unwindstack/UserArm64.h>
#include <unwindstack/UserX86.h>
#include <unwindstack/UserX86_64.h>
#include "environment.h"
#include "perf_regs.h"
#include "read_apk.h"
#include "thread_tree.h"
static_assert(simpleperf::map_flags::PROT_JIT_SYMFILE_MAP ==
unwindstack::MAPS_FLAGS_JIT_SYMFILE_MAP, "");
namespace simpleperf {
// Max frames seen so far is 463, in http://b/110923759.
static constexpr size_t MAX_UNWINDING_FRAMES = 512;
static unwindstack::Regs* GetBacktraceRegs(const RegSet& regs) {
switch (regs.arch) {
case ARCH_ARM: {
unwindstack::arm_user_regs arm_user_regs;
memset(&arm_user_regs, 0, sizeof(arm_user_regs));
static_assert(
static_cast<int>(unwindstack::ARM_REG_R0) == static_cast<int>(PERF_REG_ARM_R0), "");
static_assert(
static_cast<int>(unwindstack::ARM_REG_LAST) == static_cast<int>(PERF_REG_ARM_MAX), "");
for (size_t i = unwindstack::ARM_REG_R0; i < unwindstack::ARM_REG_LAST; ++i) {
arm_user_regs.regs[i] = static_cast<uint32_t>(regs.data[i]);
}
return unwindstack::RegsArm::Read(&arm_user_regs);
}
case ARCH_ARM64: {
unwindstack::arm64_user_regs arm64_user_regs;
memset(&arm64_user_regs, 0, sizeof(arm64_user_regs));
static_assert(
static_cast<int>(unwindstack::ARM64_REG_R0) == static_cast<int>(PERF_REG_ARM64_X0), "");
static_assert(
static_cast<int>(unwindstack::ARM64_REG_R30) == static_cast<int>(PERF_REG_ARM64_LR), "");
memcpy(&arm64_user_regs.regs[unwindstack::ARM64_REG_R0], ®s.data[PERF_REG_ARM64_X0],
sizeof(uint64_t) * (PERF_REG_ARM64_LR - PERF_REG_ARM64_X0 + 1));
arm64_user_regs.sp = regs.data[PERF_REG_ARM64_SP];
arm64_user_regs.pc = regs.data[PERF_REG_ARM64_PC];
return unwindstack::RegsArm64::Read(&arm64_user_regs);
}
case ARCH_X86_32: {
unwindstack::x86_user_regs x86_user_regs;
memset(&x86_user_regs, 0, sizeof(x86_user_regs));
x86_user_regs.eax = static_cast<uint32_t>(regs.data[PERF_REG_X86_AX]);
x86_user_regs.ebx = static_cast<uint32_t>(regs.data[PERF_REG_X86_BX]);
x86_user_regs.ecx = static_cast<uint32_t>(regs.data[PERF_REG_X86_CX]);
x86_user_regs.edx = static_cast<uint32_t>(regs.data[PERF_REG_X86_DX]);
x86_user_regs.ebp = static_cast<uint32_t>(regs.data[PERF_REG_X86_BP]);
x86_user_regs.edi = static_cast<uint32_t>(regs.data[PERF_REG_X86_DI]);
x86_user_regs.esi = static_cast<uint32_t>(regs.data[PERF_REG_X86_SI]);
x86_user_regs.esp = static_cast<uint32_t>(regs.data[PERF_REG_X86_SP]);
x86_user_regs.eip = static_cast<uint32_t>(regs.data[PERF_REG_X86_IP]);
return unwindstack::RegsX86::Read(&x86_user_regs);
}
case ARCH_X86_64: {
unwindstack::x86_64_user_regs x86_64_user_regs;
memset(&x86_64_user_regs, 0, sizeof(x86_64_user_regs));
x86_64_user_regs.rax = regs.data[PERF_REG_X86_AX];
x86_64_user_regs.rbx = regs.data[PERF_REG_X86_BX];
x86_64_user_regs.rcx = regs.data[PERF_REG_X86_CX];
x86_64_user_regs.rdx = regs.data[PERF_REG_X86_DX];
x86_64_user_regs.r8 = regs.data[PERF_REG_X86_R8];
x86_64_user_regs.r9 = regs.data[PERF_REG_X86_R9];
x86_64_user_regs.r10 = regs.data[PERF_REG_X86_R10];
x86_64_user_regs.r11 = regs.data[PERF_REG_X86_R11];
x86_64_user_regs.r12 = regs.data[PERF_REG_X86_R12];
x86_64_user_regs.r13 = regs.data[PERF_REG_X86_R13];
x86_64_user_regs.r14 = regs.data[PERF_REG_X86_R14];
x86_64_user_regs.r15 = regs.data[PERF_REG_X86_R15];
x86_64_user_regs.rdi = regs.data[PERF_REG_X86_DI];
x86_64_user_regs.rsi = regs.data[PERF_REG_X86_SI];
x86_64_user_regs.rbp = regs.data[PERF_REG_X86_BP];
x86_64_user_regs.rsp = regs.data[PERF_REG_X86_SP];
x86_64_user_regs.rip = regs.data[PERF_REG_X86_IP];
return unwindstack::RegsX86_64::Read(&x86_64_user_regs);
}
default:
return nullptr;
}
}
static unwindstack::MapInfo* CreateMapInfo(const MapEntry* entry) {
const char* name = entry->dso->GetDebugFilePath().c_str();
uint64_t pgoff = entry->pgoff;
if (entry->pgoff == 0) {
auto tuple = SplitUrlInApk(entry->dso->GetDebugFilePath());
if (std::get<0>(tuple)) {
// The unwinder does not understand the ! format, so change back to
// the previous format (apk, offset).
EmbeddedElf* elf = ApkInspector::FindElfInApkByName(std::get<1>(tuple), std::get<2>(tuple));
if (elf != nullptr) {
name = elf->filepath().c_str();
pgoff = elf->entry_offset();
}
}
}
return new unwindstack::MapInfo(nullptr, entry->start_addr, entry->get_end_addr(), pgoff,
PROT_READ | PROT_EXEC | entry->flags, name);
}
void UnwindMaps::UpdateMaps(const MapSet& map_set) {
if (version_ == map_set.version) {
return;
}
version_ = map_set.version;
size_t i = 0;
size_t old_size = entries_.size();
for (auto it = map_set.maps.begin(); it != map_set.maps.end();) {
const MapEntry* entry = it->second;
if (i < old_size && entry == entries_[i]) {
i++;
++it;
} else if (i == old_size || entry->start_addr <= entries_[i]->start_addr) {
// Add an entry.
entries_.push_back(entry);
maps_.emplace_back(CreateMapInfo(entry));
++it;
} else {
// Remove an entry.
entries_[i] = nullptr;
maps_[i++] = nullptr;
}
}
while (i < old_size) {
entries_[i] = nullptr;
maps_[i++] = nullptr;
}
std::sort(entries_.begin(), entries_.end(), [](const auto& e1, const auto& e2) {
if (e1 == nullptr || e2 == nullptr) {
return e1 != nullptr;
}
return e1->start_addr < e2->start_addr;
});
std::sort(maps_.begin(), maps_.end(),
[](const auto& m1, const auto& m2) {
if (m1 == nullptr || m2 == nullptr) {
return m1 != nullptr;
}
return m1->start < m2->start;
});
entries_.resize(map_set.maps.size());
maps_.resize(map_set.maps.size());
}
OfflineUnwinder::OfflineUnwinder(bool collect_stat) : collect_stat_(collect_stat) {
unwindstack::Elf::SetCachingEnabled(true);
}
bool OfflineUnwinder::UnwindCallChain(const ThreadEntry& thread, const RegSet& regs,
const char* stack, size_t stack_size,
std::vector<uint64_t>* ips, std::vector<uint64_t>* sps) {
uint64_t start_time;
if (collect_stat_) {
start_time = GetSystemClock();
}
is_callchain_broken_for_incomplete_jit_debug_info_ = false;
ips->clear();
sps->clear();
std::vector<uint64_t> result;
uint64_t sp_reg_value;
if (!regs.GetSpRegValue(&sp_reg_value)) {
LOG(ERROR) << "can't get sp reg value";
return false;
}
uint64_t stack_addr = sp_reg_value;
UnwindMaps& cached_map = cached_maps_[thread.pid];
cached_map.UpdateMaps(*thread.maps);
std::shared_ptr<unwindstack::MemoryOfflineBuffer> stack_memory(
new unwindstack::MemoryOfflineBuffer(reinterpret_cast<const uint8_t*>(stack),
stack_addr, stack_addr + stack_size));
std::unique_ptr<unwindstack::Regs> unwind_regs(GetBacktraceRegs(regs));
if (!unwind_regs) {
return false;
}
unwindstack::Unwinder unwinder(MAX_UNWINDING_FRAMES, &cached_map, unwind_regs.get(),
stack_memory);
unwinder.SetResolveNames(false);
unwinder.Unwind();
size_t last_jit_method_frame = UINT_MAX;
for (auto& frame : unwinder.frames()) {
// Unwinding in arm architecture can return 0 pc address.
// If frame.map.start == 0, this frame doesn't hit any map, it could be:
// 1. In an executable map not backed by a file. Note that RecordCommand::ShouldOmitRecord()
// may omit maps only exist memory.
// 2. An incorrectly unwound frame. Like caused by invalid stack data, as in
// SampleRecord::GetValidStackSize(). Or caused by incomplete JIT debug info.
// We want to remove this frame and callchains following it in either case.
if (frame.pc == 0 || frame.map_start == 0) {
is_callchain_broken_for_incomplete_jit_debug_info_ = true;
break;
}
if (frame.map_flags & unwindstack::MAPS_FLAGS_JIT_SYMFILE_MAP) {
last_jit_method_frame = ips->size();
}
ips->push_back(frame.pc);
sps->push_back(frame.sp);
}
// If the unwound frames stop near to a JITed method, it may be caused by incomplete JIT debug
// info.
if (last_jit_method_frame != UINT_MAX && last_jit_method_frame + 3 > ips->size()) {
is_callchain_broken_for_incomplete_jit_debug_info_ = true;
}
uint64_t ip_reg_value;
if (!regs.GetIpRegValue(&ip_reg_value)) {
LOG(ERROR) << "can't get ip reg value";
return false;
}
if (ips->empty()) {
ips->push_back(ip_reg_value);
sps->push_back(sp_reg_value);
} else {
// Check if the unwinder returns ip reg value as the first ip address in callstack.
CHECK_EQ((*ips)[0], ip_reg_value);
}
if (collect_stat_) {
unwinding_result_.used_time = GetSystemClock() - start_time;
switch (unwinder.LastErrorCode()) {
case unwindstack::ERROR_MAX_FRAMES_EXCEEDED:
unwinding_result_.stop_reason = UnwindingResult::EXCEED_MAX_FRAMES_LIMIT;
break;
case unwindstack::ERROR_MEMORY_INVALID: {
uint64_t addr = unwinder.LastErrorAddress();
// Because we don't have precise stack range here, just guess an addr is in stack
// if sp - 128K <= addr <= sp.
if (addr <= stack_addr && addr >= stack_addr - 128 * 1024) {
unwinding_result_.stop_reason = UnwindingResult::ACCESS_STACK_FAILED;
} else {
unwinding_result_.stop_reason = UnwindingResult::ACCESS_MEM_FAILED;
}
unwinding_result_.stop_info.addr = addr;
break;
}
case unwindstack::ERROR_INVALID_MAP:
unwinding_result_.stop_reason = UnwindingResult::MAP_MISSING;
break;
default:
unwinding_result_.stop_reason = UnwindingResult::UNKNOWN_REASON;
break;
}
unwinding_result_.stack_start = stack_addr;
unwinding_result_.stack_end = stack_addr + stack_size;
}
return true;
}
} // namespace simpleperf