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/*
* Copyright (C) 2016 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 <stdint.h>
#include <sys/ptrace.h>
#include <sys/uio.h>
#include <vector>
#include <unwindstack/Elf.h>
#include <unwindstack/MapInfo.h>
#include <unwindstack/Regs.h>
#include <unwindstack/RegsArm.h>
#include <unwindstack/RegsArm64.h>
#include <unwindstack/RegsMips.h>
#include <unwindstack/RegsMips64.h>
#include <unwindstack/RegsX86.h>
#include <unwindstack/RegsX86_64.h>
#include <unwindstack/UserArm.h>
#include <unwindstack/UserArm64.h>
#include <unwindstack/UserMips.h>
#include <unwindstack/UserMips64.h>
#include <unwindstack/UserX86.h>
#include <unwindstack/UserX86_64.h>
namespace unwindstack {
// The largest user structure.
constexpr size_t MAX_USER_REGS_SIZE = sizeof(mips64_user_regs) + 10;
// This function assumes that reg_data is already aligned to a 64 bit value.
// If not this could crash with an unaligned access.
Regs* Regs::RemoteGet(pid_t pid) {
// Make the buffer large enough to contain the largest registers type.
std::vector<uint64_t> buffer(MAX_USER_REGS_SIZE / sizeof(uint64_t));
struct iovec io;
io.iov_base = buffer.data();
io.iov_len = buffer.size() * sizeof(uint64_t);
if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, reinterpret_cast<void*>(&io)) == -1) {
return nullptr;
}
switch (io.iov_len) {
case sizeof(x86_user_regs):
return RegsX86::Read(buffer.data());
case sizeof(x86_64_user_regs):
return RegsX86_64::Read(buffer.data());
case sizeof(arm_user_regs):
return RegsArm::Read(buffer.data());
case sizeof(arm64_user_regs):
return RegsArm64::Read(buffer.data());
case sizeof(mips_user_regs):
return RegsMips::Read(buffer.data());
case sizeof(mips64_user_regs):
return RegsMips64::Read(buffer.data());
}
return nullptr;
}
Regs* Regs::CreateFromUcontext(ArchEnum arch, void* ucontext) {
switch (arch) {
case ARCH_X86:
return RegsX86::CreateFromUcontext(ucontext);
case ARCH_X86_64:
return RegsX86_64::CreateFromUcontext(ucontext);
case ARCH_ARM:
return RegsArm::CreateFromUcontext(ucontext);
case ARCH_ARM64:
return RegsArm64::CreateFromUcontext(ucontext);
case ARCH_MIPS:
return RegsMips::CreateFromUcontext(ucontext);
case ARCH_MIPS64:
return RegsMips64::CreateFromUcontext(ucontext);
case ARCH_UNKNOWN:
default:
return nullptr;
}
}
ArchEnum Regs::CurrentArch() {
#if defined(__arm__)
return ARCH_ARM;
#elif defined(__aarch64__)
return ARCH_ARM64;
#elif defined(__i386__)
return ARCH_X86;
#elif defined(__x86_64__)
return ARCH_X86_64;
#else
abort();
#endif
}
Regs* Regs::CreateFromLocal() {
Regs* regs;
#if defined(__arm__)
regs = new RegsArm();
#elif defined(__aarch64__)
regs = new RegsArm64();
#elif defined(__i386__)
regs = new RegsX86();
#elif defined(__x86_64__)
regs = new RegsX86_64();
#else
abort();
#endif
return regs;
}
uint64_t GetPcAdjustment(uint64_t rel_pc, Elf* elf, ArchEnum arch) {
switch (arch) {
case ARCH_ARM: {
if (!elf->valid()) {
return 2;
}
uint64_t load_bias = elf->GetLoadBias();
if (rel_pc < load_bias) {
if (rel_pc < 2) {
return 0;
}
return 2;
}
uint64_t adjusted_rel_pc = rel_pc - load_bias;
if (adjusted_rel_pc < 5) {
if (adjusted_rel_pc < 2) {
return 0;
}
return 2;
}
if (adjusted_rel_pc & 1) {
// This is a thumb instruction, it could be 2 or 4 bytes.
uint32_t value;
if (!elf->memory()->ReadFully(adjusted_rel_pc - 5, &value, sizeof(value)) ||
(value & 0xe000f000) != 0xe000f000) {
return 2;
}
}
return 4;
}
case ARCH_ARM64: {
if (rel_pc < 4) {
return 0;
}
return 4;
}
case ARCH_MIPS:
case ARCH_MIPS64: {
if (rel_pc < 8) {
return 0;
}
// For now, just assume no compact branches
return 8;
}
case ARCH_X86:
case ARCH_X86_64: {
if (rel_pc == 0) {
return 0;
}
return 1;
}
case ARCH_UNKNOWN:
return 0;
}
}
} // namespace unwindstack