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/*
* Copyright (C) 2017 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 <string.h>
#include <functional>
#include <unwindstack/Elf.h>
#include <unwindstack/MachineMips.h>
#include <unwindstack/MapInfo.h>
#include <unwindstack/Memory.h>
#include <unwindstack/RegsMips.h>
#include <unwindstack/UcontextMips.h>
#include <unwindstack/UserMips.h>
namespace unwindstack {
RegsMips::RegsMips()
: RegsImpl<uint32_t>(MIPS_REG_LAST, Location(LOCATION_REGISTER, MIPS_REG_RA)) {}
ArchEnum RegsMips::Arch() {
return ARCH_MIPS;
}
uint64_t RegsMips::pc() {
return regs_[MIPS_REG_PC];
}
uint64_t RegsMips::sp() {
return regs_[MIPS_REG_SP];
}
void RegsMips::set_pc(uint64_t pc) {
regs_[MIPS_REG_PC] = static_cast<uint32_t>(pc);
}
void RegsMips::set_sp(uint64_t sp) {
regs_[MIPS_REG_SP] = static_cast<uint32_t>(sp);
}
uint64_t RegsMips::GetPcAdjustment(uint64_t rel_pc, Elf*) {
if (rel_pc < 8) {
return 0;
}
// For now, just assume no compact branches
return 8;
}
bool RegsMips::SetPcFromReturnAddress(Memory*) {
uint32_t ra = regs_[MIPS_REG_RA];
if (regs_[MIPS_REG_PC] == ra) {
return false;
}
regs_[MIPS_REG_PC] = ra;
return true;
}
void RegsMips::IterateRegisters(std::function<void(const char*, uint64_t)> fn) {
fn("r0", regs_[MIPS_REG_R0]);
fn("r1", regs_[MIPS_REG_R1]);
fn("r2", regs_[MIPS_REG_R2]);
fn("r3", regs_[MIPS_REG_R3]);
fn("r4", regs_[MIPS_REG_R4]);
fn("r5", regs_[MIPS_REG_R5]);
fn("r6", regs_[MIPS_REG_R6]);
fn("r7", regs_[MIPS_REG_R7]);
fn("r8", regs_[MIPS_REG_R8]);
fn("r9", regs_[MIPS_REG_R9]);
fn("r10", regs_[MIPS_REG_R10]);
fn("r11", regs_[MIPS_REG_R11]);
fn("r12", regs_[MIPS_REG_R12]);
fn("r13", regs_[MIPS_REG_R13]);
fn("r14", regs_[MIPS_REG_R14]);
fn("r15", regs_[MIPS_REG_R15]);
fn("r16", regs_[MIPS_REG_R16]);
fn("r17", regs_[MIPS_REG_R17]);
fn("r18", regs_[MIPS_REG_R18]);
fn("r19", regs_[MIPS_REG_R19]);
fn("r20", regs_[MIPS_REG_R20]);
fn("r21", regs_[MIPS_REG_R21]);
fn("r22", regs_[MIPS_REG_R22]);
fn("r23", regs_[MIPS_REG_R23]);
fn("r24", regs_[MIPS_REG_R24]);
fn("r25", regs_[MIPS_REG_R25]);
fn("r26", regs_[MIPS_REG_R26]);
fn("r27", regs_[MIPS_REG_R27]);
fn("r28", regs_[MIPS_REG_R28]);
fn("sp", regs_[MIPS_REG_SP]);
fn("r30", regs_[MIPS_REG_R30]);
fn("ra", regs_[MIPS_REG_RA]);
fn("pc", regs_[MIPS_REG_PC]);
}
Regs* RegsMips::Read(void* remote_data) {
mips_user_regs* user = reinterpret_cast<mips_user_regs*>(remote_data);
RegsMips* regs = new RegsMips();
uint32_t* reg_data = reinterpret_cast<uint32_t*>(regs->RawData());
memcpy(regs->RawData(), &user->regs[MIPS32_EF_R0], (MIPS_REG_R31 + 1) * sizeof(uint32_t));
reg_data[MIPS_REG_PC] = user->regs[MIPS32_EF_CP0_EPC];
return regs;
}
Regs* RegsMips::CreateFromUcontext(void* ucontext) {
mips_ucontext_t* mips_ucontext = reinterpret_cast<mips_ucontext_t*>(ucontext);
RegsMips* regs = new RegsMips();
// Copy 64 bit sc_regs over to 32 bit regs
for (int i = 0; i < 32; i++) {
(*regs)[MIPS_REG_R0 + i] = mips_ucontext->uc_mcontext.sc_regs[i];
}
(*regs)[MIPS_REG_PC] = mips_ucontext->uc_mcontext.sc_pc;
return regs;
}
bool RegsMips::StepIfSignalHandler(uint64_t rel_pc, Elf* elf, Memory* process_memory) {
uint64_t data;
uint64_t offset = 0;
Memory* elf_memory = elf->memory();
// Read from elf memory since it is usually more expensive to read from
// process memory.
if (!elf_memory->ReadFully(rel_pc, &data, sizeof(data))) {
return false;
}
// Look for the kernel sigreturn functions.
// __vdso_rt_sigreturn:
// 0x24021061 li v0, 0x1061
// 0x0000000c syscall
// __vdso_sigreturn:
// 0x24021017 li v0, 0x1017
// 0x0000000c syscall
if (data == 0x0000000c24021061ULL) {
// vdso_rt_sigreturn => read rt_sigframe
// offset = siginfo offset + sizeof(siginfo) + uc_mcontext offset + sc_pc offset
offset = 24 + 128 + 24 + 8;
} else if (data == 0x0000000c24021017LL) {
// vdso_sigreturn => read sigframe
// offset = sigcontext offset + sc_pc offset
offset = 24 + 8;
} else {
return false;
}
// read sc_pc and sc_regs[32] from stack
uint64_t values[MIPS_REG_LAST];
if (!process_memory->ReadFully(regs_[MIPS_REG_SP] + offset, values, sizeof(values))) {
return false;
}
// Copy 64 bit sc_pc over to 32 bit regs_[MIPS_REG_PC]
regs_[MIPS_REG_PC] = values[0];
// Copy 64 bit sc_regs over to 32 bit regs
for (int i = 0; i < 32; i++) {
regs_[MIPS_REG_R0 + i] = values[1 + i];
}
return true;
}
Regs* RegsMips::Clone() {
return new RegsMips(*this);
}
} // namespace unwindstack