patch_hook_area.cpp

#include "patch_hook_area.h"
#include "analyze/base_func.h"
#include "3rdparty/aarch64_asm_helper.h"

using namespace asmjit;
using namespace asmjit::a64;
using namespace asmjit::a64::Predicate;

PatchHookArea::PatchHookArea(const PatchBase66& patch_base)
    : PatchBase66(patch_base) {}

PatchHookArea::~PatchHookArea() {}

size_t PatchHookArea::reserve_hook_trampoline_area(
    const SymbolRegion& hook_func_start_region,
    size_t& out_area_start,
    size_t& out_area_size,
    std::vector<patch_bytes_data>& vec_out_patch_bytes_data)
{
    size_t hook_func_start_addr = hook_func_start_region.offset;
    if (hook_func_start_addr == 0) { return 0; }
    std::cout << "Reserving hook trampoline area at: 0x" << std::hex << hook_func_start_addr << std::endl << std::endl;

    // 计算可用空间
    size_t available_size = hook_func_start_region.size;
    size_t reserve_size = std::min(available_size, HOOK_TRAMPOLINE_SIZE);

    if (reserve_size < HOOK_AREA_HEADER_SIZE + 256) {
        std::cout << "[发生错误] Not enough space for hook trampoline area" << std::endl;
        return 0;
    }

    // 输出跳板区信息
    out_area_start = hook_func_start_addr + HOOK_AREA_HEADER_SIZE;
    out_area_size = reserve_size - HOOK_AREA_HEADER_SIZE;

    // 初始化跳板区头部
    // 布局:
    // [0]: base_addr (用于验证)
    // [8]: used_offset (初始为0)
    struct HookAreaHeader {
        uint64_t base_addr;
        uint64_t used_offset;
    } header;
    
    header.base_addr = out_area_start;
    header.used_offset = 0;

    std::string str_bytes = bytes2hex((const unsigned char*)&header, sizeof(header));

    // 填充剩余空间为NOP (便于调试)
    // NOP指令: 0xD503201F
    uint32_t nop_insn = 0xD503201F;
    for (size_t i = HOOK_AREA_HEADER_SIZE; i < reserve_size; i += 4) {
        str_bytes += bytes2hex((const unsigned char*)&nop_insn, sizeof(nop_insn));
    }

    vec_out_patch_bytes_data.push_back({ str_bytes, hook_func_start_addr });

    std::cout << "Hook trampoline area reserved:" << std::endl;
    std::cout << "  Header address: 0x" << std::hex << hook_func_start_addr << std::endl;
    std::cout << "  Handler area start: 0x" << std::hex << out_area_start << std::endl;
    std::cout << "  Available size: " << std::dec << out_area_size << " bytes" << std::endl;

    return reserve_size;
}