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https://gitlab.com/Mr_Goldberg/goldberg_emulator.git
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Linux version of detour
This commit is contained in:
Nemirtingas
parent
b6eb929383
commit
92ed36f499
2 changed files with 669 additions and 0 deletions
637
overlay_experimental/Linux_Detour.cpp
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637
overlay_experimental/Linux_Detour.cpp
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@ -0,0 +1,637 @@
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#include "Linux_Detour.h"
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#include <algorithm>
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#include <list>
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#include <cstdint>
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#include <unistd.h>
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#include <malloc.h>
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#include <sys/mman.h>
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#include <errno.h>
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//------------------------------------------------------------------------------//
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// Helper funcs
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//------------------------------------------------------------------------------//
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constexpr static auto relative_jump_size = 5;
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constexpr static auto relative_addr_jump_size = sizeof(int32_t);
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constexpr static auto absolute_jump_size = 6;
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struct
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{
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bool has_r_m;
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uint8_t base_size;
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} s_opcodes[256] =
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{
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 0 - 7
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 8 - 15
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 16 - 23
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 24 - 31
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 32 - 39
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 40 - 47
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 48 - 55
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 56 - 63
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 64 - 71
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 72 - 79
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// PUSH ...
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{false, 1}, {false, 1}, {false, 1}, {false, 1}, {false, 1}, {false, 1}, {false, 1}, {false, 1}, // 80 - 87
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// POP ...
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{false, 1}, {false, 1}, {false, 1}, {false, 1}, {false, 1}, {false, 1}, {false, 1}, {false, 1}, // 88 - 95
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 96 - 103
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 104 - 111
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 112 - 129
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 120 - 127
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// MOV, ADD, ... R8 <- IMM8 TEST_8 TEST XCHG_8 XCHG
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{true , 3}, {true , 6}, {true , 3}, {true , 3}, {true , 2}, {true , 2}, {true , 2}, {true , 2}, // 128 - 135
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// MOV_8 MOV MOV_R8_B MOV_R32_D MOV_32_ES LEA MOV_ES_32 POP
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{true , 2}, {true , 2}, {true , 2}, {true , 2}, {true , 2}, {true , 2}, {true , 2}, {false, 2}, // 136 - 143
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// NOP
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{false, 1}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 144 - 151
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 152 - 159
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 160 - 167
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 168 - 175
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// MOV_AL MOV_CL MOV_DL MOV_BL MOV_AH MOV_CH MOV_DH MOV_BH
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{false, 2}, {false, 2}, {false, 2}, {false, 2}, {false, 2}, {false, 2}, {false, 2}, {false, 2}, // 176 - 183
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// MOV_EAX MOV_ECX MOV_EDX MOV_EBX MOV_ESP MOV_EBP MOV_ESI MOV_EDI,
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{false, 5}, {false, 5}, {false, 5}, {false, 5}, {false, 5}, {false, 5}, {false, 5}, {false, 5}, // 184 - 191
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// RETN_IMM16 RETN
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{false, 0}, {false, 0}, {false, 3}, {false, 1}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 192 - 199
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// LEAVE RETF_IMM16 RETF INT INT_IMM8 INTO
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{false, 0}, {false, 1}, {false, 3}, {false, 1}, {false, 1}, {false, 1}, {false, 1}, {false, 0}, // 200 - 207
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 208 - 215
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 216 - 223
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 224 - 231
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// CALL JMP LJMP SHORT_JMP
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 232 - 239
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, // 240 - 247
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// EXTENDED
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{false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 0}, {false, 6}, // 248 - 255
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};
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static constexpr auto mod_mask = 0xC0;
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static constexpr auto register_addressing_mode = 0xC0;
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static constexpr auto four_bytes_signed_displacement = 0x80;
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static constexpr auto one_byte_signed_displacement = 0x40;
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static constexpr auto rm_mask = 0x05;
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static constexpr auto displacement_only_addressing = 0x05;
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static constexpr auto sib_with_no_displacement = 0x04;
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static constexpr auto register_indirect_addressing_mode = 0x00;
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enum opcodes_e // Commonly used opcode in the beginning of functions
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{
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PUSH_EAX = 0x50, PUSH_ECX, PUSH_EDX, PUSH_EBX, PUSH_ESP, PUSH_EBP, PUSH_ESI, PUSH_EDI,
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POP_EAX , POP_ECX , POP_EDX , POP_EBX , POP_ESP , POP_EBP , POP_ESI , POP_EDI ,
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R8_IMM8 = 0x80, R32_IMM32, R8_IMM8_2, R32_IMM8,
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TEST_8, TEST,
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XCHG_8, XCHG,
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MOV_8 , MOV,
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MOV_8_B, MOV_32_D, MOV_32_ES,
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LEA,
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MOV_ES_32, POP,
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NOP,
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MOV_AL = 0xB0, MOV_CL, MOV_DL, MOV_BL, MOV_AH, MOV_CH, MOV_DH, MOV_BH,
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MOV_EAX, MOV_ECX, MOV_EDX, MOV_EBX, MOV_ESP, MOV_EBP, MOV_ESI, MOV_EDI,
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RETN_IMM16 = 0xC2, RETN,
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LEAVE = 0xC9, RETF_IMM16, RETF, INT, INT_IMM8, INTO,
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CALL = 0xE8, // 5 bytes don't process
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JMP, // 5 bytes don't process
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LJMP, // 7 bytes, don't process
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SHORT_JMP, // 2 bytes don't process
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EXTENDED = 0xFF,
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};
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const char* opcode_name(uint8_t opcode)
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{
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#define NAME(opcode_name) case opcode_name: return #opcode_name
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switch( opcode )
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{
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NAME(PUSH_EAX); NAME(PUSH_ECX); NAME(PUSH_EDX); NAME(PUSH_EBX);
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NAME(PUSH_ESP); NAME(PUSH_EBP); NAME(PUSH_ESI); NAME(PUSH_EDI);
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NAME(POP_EAX); NAME(POP_ECX); NAME(POP_EDX); NAME(POP_EBX);
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NAME(POP_ESP); NAME(POP_EBP); NAME(POP_ESI); NAME(POP_EDI);
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NAME(R8_IMM8); NAME(R32_IMM32); NAME(R8_IMM8_2); NAME(R32_IMM8);
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NAME(TEST_8); NAME(TEST); NAME(XCHG_8); NAME(XCHG); NAME(MOV_8); NAME(MOV);
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NAME(MOV_8_B); NAME(MOV_32_D); NAME(MOV_32_ES);
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NAME(LEA);
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NAME(MOV_ES_32); NAME(POP);
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NAME(NOP);
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NAME(MOV_AL) ; NAME(MOV_CL) ; NAME(MOV_DL) ; NAME(MOV_BL) ; NAME(MOV_AH) ; NAME(MOV_CH) ; NAME(MOV_DH) ; NAME(MOV_BH) ;
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NAME(MOV_EAX); NAME(MOV_ECX); NAME(MOV_EDX); NAME(MOV_EBX); NAME(MOV_ESP); NAME(MOV_EBP); NAME(MOV_ESI); NAME(MOV_EDI);
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NAME(RETN_IMM16); NAME(RETN); NAME(LEAVE); NAME(RETF_IMM16); NAME(RETF);
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NAME(INT); NAME(INT_IMM8); NAME(INTO); NAME(CALL); NAME(JMP); NAME(LJMP); NAME(SHORT_JMP);
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NAME(EXTENDED);
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}
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#undef NAME
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return "no registered";
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}
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#pragma pack(push, 1)
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struct trampoline_x86_t
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{
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uint8_t trampolineBytes[16+relative_jump_size]; // trampoline + original function opcodes
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uint8_t hookJump[relative_jump_size]; // jump to hook addr, needed because of relative jump overflow
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uint8_t nOriginalBytes; // number of original function bytes bkp
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uint8_t originalBytes[16]; // original function bytes
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};
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typedef trampoline_x86_t trampoline_t;
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struct trampoline_region_t
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{
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uint32_t header;
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uint8_t numTrampolines; // current trampolines allocated
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trampoline_t *trampolines_start; // start pointer of current region trampolines
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trampoline_t *next_free_trampoline; // next free trampoline in region
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};
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#pragma pack(pop)
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struct transaction_t
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{
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bool detach;
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void** ppOriginalFunc;
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trampoline_t *trampoline;
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};
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static std::list<trampoline_region_t> trampoline_regions;
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static bool transaction_started = false;
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static std::list<transaction_t> cur_transaction;
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inline size_t page_size()
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{
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static size_t _page_size = sysconf(_SC_PAGESIZE);
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return _page_size;
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}
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inline size_t region_size()
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{
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return page_size();
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}
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static uint8_t max_trampolines_in_region = region_size() / sizeof(trampoline_t);
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inline void* library_address_by_handle(void *library)
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{
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return (library == nullptr ? nullptr : *reinterpret_cast<void**>(library));
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}
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inline size_t page_align(size_t size, size_t page_size)
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{
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return (size+(page_size-1)) & (((size_t)-1)^(page_size-1));
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}
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inline void* page_addr(void* addr, size_t page_size)
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{
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return reinterpret_cast<void*>(reinterpret_cast<size_t>(addr) & (((size_t)-1)^(page_size-1)));
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}
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////////////////////////////////////////////////////
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/// Tiny disasm
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bool is_opcode_terminating_function(uint8_t* pCode)
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{
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switch( *pCode )
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{
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case LEAVE:
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case RETN: case RETN_IMM16:
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case RETF: case RETF_IMM16:
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case INT: case INT_IMM8: case INTO:
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return true;
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}
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return false;
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}
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int find_space_for_trampoline(uint8_t* func, int bytes_needed)
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{
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if( func == nullptr )
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return -1;
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int code_len = -1;
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bool search = true;
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uint8_t *startCode = reinterpret_cast<uint8_t*>(func);
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uint8_t *pCode = startCode;
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while( search ) // Find opcodes size and try to find at least 5 bytes for our JMP
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{
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if( is_opcode_terminating_function(pCode) )
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break;
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if( s_opcodes[*pCode].has_r_m )
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{ // MOD-REG-R/M Byte
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// 7 6 5 4 3 2 1 0 - bits
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//[ MOD ][ REG ][ R/M ]
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switch( pCode[1] & mod_mask ) // Check MOD to know how many bytes we have after this opcode
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{
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case register_addressing_mode : pCode += s_opcodes[*pCode].base_size ; break;// register addressing mode [opcode] [R/M] [XX]
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case four_bytes_signed_displacement: pCode += s_opcodes[*pCode].base_size+5; break;// address mode byte + 4 bytes displacement
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case one_byte_signed_displacement : pCode += s_opcodes[*pCode].base_size+2; break;// address mode byte + 1 byte displacement
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case 0x00:
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switch( pCode[1] & rm_mask )
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{
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case sib_with_no_displacement : pCode += s_opcodes[*pCode].base_size+1; break;// SIB with no displacement
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case displacement_only_addressing : pCode += s_opcodes[*pCode].base_size+4; break;// 4 bytes Displacement only addressing mode
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case register_indirect_addressing_mode: pCode += s_opcodes[*pCode].base_size; // Register indirect addressing mode
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}
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}
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}
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else if( s_opcodes[*pCode].base_size )
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{
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pCode += s_opcodes[*pCode].base_size;
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}
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else
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{
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switch( *pCode )
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{
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case CALL: case JMP: case LJMP: case SHORT_JMP:
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//std::cerr << "CALL and JMP are not supported for trampolines." << std::endl;
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search = false;
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break;
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case EXTENDED:
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//std::cerr << "IMPORT_JUMP is not handled" << std::endl;
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if (pCode[1] == 0x25) // This is an imported function
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{ // Get the true function call
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//pCode = (uint8_t*)*(pCode+2);
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//startCode = pCode;
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// For now disable this case
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search = false;
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}
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else
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{
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search = false;
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}
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break;
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default:
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//std::cerr << "opcode " << std::hex << (uint32_t)*pCode << " no registered" << std::endl;
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search = false;
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}
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}
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if( (pCode - startCode) >= bytes_needed && search )
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{
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search = false;
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code_len = pCode-startCode;
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}
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}
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return code_len;
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}
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///////////////////////////////////////////
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// Tiny asm
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inline uint8_t* gen_immediate_addr(uint8_t* opcode_addr, uint8_t* dest)
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{
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*reinterpret_cast<int32_t*>(opcode_addr) = (dest - (opcode_addr + relative_addr_jump_size));
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return opcode_addr + relative_addr_jump_size;
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}
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inline uint8_t* gen_immediate_jump(uint8_t* opcode_addr, uint8_t* dest)
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{
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*opcode_addr++ = JMP;
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return gen_immediate_addr(opcode_addr, dest);
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}
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inline uint8_t* gen_immediate_call(uint8_t* opcode_addr, uint8_t* dest)
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{
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*opcode_addr++ = CALL;
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return gen_immediate_addr(opcode_addr, dest);
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}
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uint8_t* relative_addr_to_absolute(int32_t rel_addr, uint8_t *code_addr)
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{
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return code_addr + rel_addr + relative_jump_size;
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}
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void alloc_new_trampoline_region()
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{
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trampoline_region_t region;
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region.numTrampolines = 0;
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// allocate new trampoline right in the middle of memory so relative jump can access any function
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region.trampolines_start = reinterpret_cast<trampoline_t*>(mmap((void*)std::numeric_limits<int32_t>::max(), // allocate the page near the half of memory addressing
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region_size(), // size
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PROT_EXEC|PROT_WRITE|PROT_READ, // protection
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MAP_PRIVATE|MAP_32BIT|MAP_ANONYMOUS, // don't map a file but memory
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-1, // fd = -1
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0) // offset
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);
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// Fill the region with 0
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std::fill(reinterpret_cast<uint8_t*>(region.trampolines_start), reinterpret_cast<uint8_t*>(region.trampolines_start)+region_size(), 0);
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region.next_free_trampoline = region.trampolines_start;
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// Protect trampoline region memory
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mprotect((void*)region.trampolines_start, region_size(), PROT_READ|PROT_EXEC);
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trampoline_regions.push_back(region);
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}
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trampoline_t* get_free_trampoline()
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{
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if (!transaction_started)
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return nullptr;
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trampoline_t *res = nullptr;
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auto it = std::find_if(trampoline_regions.begin(), trampoline_regions.end(), [&res](trampoline_region_t ®ion){
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if( region.numTrampolines == max_trampolines_in_region )
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return false;
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return true;
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});
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if( it == trampoline_regions.end() )
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{
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alloc_new_trampoline_region();
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it = --trampoline_regions.end();
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}
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res = it->next_free_trampoline;
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trampoline_t *next_new_trampoline = res+1;
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if( it->numTrampolines != max_trampolines_in_region )
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{
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while( next_new_trampoline->nOriginalBytes != 0 )
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{
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++next_new_trampoline;
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}
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}
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else
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{
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next_new_trampoline = nullptr;
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}
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it->next_free_trampoline = next_new_trampoline;
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++it->numTrampolines;
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return res;
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}
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void clear_trampoline(trampoline_region_t& region, trampoline_t *trampoline)
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{
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--region.numTrampolines;
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|
||||
std::fill(reinterpret_cast<uint8_t*>(trampoline), reinterpret_cast<uint8_t*>(trampoline+1), 0);
|
||||
if( region.next_free_trampoline == nullptr || region.next_free_trampoline > trampoline )
|
||||
region.next_free_trampoline = trampoline;
|
||||
}
|
||||
|
||||
inline bool is_page_inside_region(void *page, trampoline_region_t& region)
|
||||
{
|
||||
if( page >= region.trampolines_start && page <= (region.trampolines_start+region_size()) )
|
||||
return true;
|
||||
return false;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------------//
|
||||
|
||||
/*
|
||||
#include <signal.h>
|
||||
#include <dirent.h>
|
||||
|
||||
static pid_t tid = 0;
|
||||
|
||||
struct dism_pthread_t
|
||||
{
|
||||
uint32_t d0;
|
||||
uint32_t d4;
|
||||
uint32_t d8;
|
||||
uint32_t dc;
|
||||
uint32_t d10;
|
||||
uint32_t d14;
|
||||
uint32_t d18;
|
||||
uint32_t d1c;
|
||||
uint32_t d20;
|
||||
uint32_t d24;
|
||||
uint32_t d28;
|
||||
uint32_t d2c;
|
||||
uint32_t d30;
|
||||
uint32_t d34;
|
||||
uint32_t d38;
|
||||
uint32_t d3c;
|
||||
uint32_t d40;
|
||||
uint32_t d44;
|
||||
uint32_t d48;
|
||||
uint32_t d4c;
|
||||
uint32_t d50;
|
||||
uint32_t d54;
|
||||
uint32_t d58;
|
||||
uint32_t d5c;
|
||||
uint32_t d60;
|
||||
uint32_t d64;
|
||||
pid_t task_id;
|
||||
};
|
||||
*/
|
||||
|
||||
int Linux_Detour::update_thread(pthread_t thread_id)
|
||||
{
|
||||
//dism_pthread_t *dt = (dism_pthread_t*)thread_id;
|
||||
|
||||
// dt->task_id == syscall(SYS_gettid);
|
||||
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int Linux_Detour::transaction_begin()
|
||||
{
|
||||
if( transaction_started )
|
||||
return -1;
|
||||
|
||||
transaction_started = true;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int Linux_Detour::transaction_abort()
|
||||
{
|
||||
if(!transaction_started)
|
||||
return -1;
|
||||
|
||||
for( auto &i : cur_transaction )
|
||||
{
|
||||
trampoline_t *trampoline = i.trampoline;
|
||||
void *page_start = page_addr(reinterpret_cast<void*>(trampoline), page_size());
|
||||
auto it = std::find_if(trampoline_regions.begin(), trampoline_regions.end(), [page_start](trampoline_region_t ®ion){
|
||||
if( is_page_inside_region(page_start, region) )
|
||||
return true;
|
||||
return false;
|
||||
});
|
||||
if( it != trampoline_regions.end() )
|
||||
{
|
||||
clear_trampoline(*it, trampoline);
|
||||
}
|
||||
}
|
||||
cur_transaction.clear();
|
||||
transaction_started = false;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int Linux_Detour::transaction_commit()
|
||||
{
|
||||
if (!transaction_started )
|
||||
return -1;
|
||||
|
||||
for( auto &i : cur_transaction)
|
||||
{
|
||||
trampoline_t *trampoline = i.trampoline;
|
||||
void **ppOriginalFunc = i.ppOriginalFunc;
|
||||
|
||||
int res;
|
||||
|
||||
if( i.detach )
|
||||
{
|
||||
void* trampoline_page = page_addr(reinterpret_cast<void*>(trampoline), page_size());
|
||||
|
||||
*ppOriginalFunc = (void*)(relative_addr_to_absolute(*reinterpret_cast<int32_t*>(trampoline->trampolineBytes+trampoline->nOriginalBytes+1),
|
||||
trampoline->trampolineBytes));
|
||||
|
||||
void* originalFunctionPage = page_addr(*ppOriginalFunc, page_size());
|
||||
|
||||
// Allow write on the original func
|
||||
res = mprotect(originalFunctionPage, page_size()*2, PROT_READ|PROT_WRITE|PROT_EXEC);
|
||||
|
||||
// Write the original opcodes
|
||||
std::copy(trampoline->originalBytes, trampoline->originalBytes+trampoline->nOriginalBytes,
|
||||
reinterpret_cast<uint8_t*>(*ppOriginalFunc));
|
||||
|
||||
// Remove write permission
|
||||
res = mprotect(originalFunctionPage, page_size()*2, PROT_READ|PROT_EXEC);
|
||||
|
||||
// Allow write on trampoline page
|
||||
res = mprotect(trampoline_page, page_size()*2, PROT_READ|PROT_WRITE|PROT_EXEC);
|
||||
|
||||
clear_trampoline(*reinterpret_cast<trampoline_region_t*>(trampoline_page), trampoline);
|
||||
|
||||
// Remove write permission
|
||||
res = mprotect(trampoline_page, page_size()*2, PROT_READ|PROT_EXEC);
|
||||
}
|
||||
else
|
||||
{
|
||||
void* originalFunctionPage = page_addr(*ppOriginalFunc, page_size());
|
||||
|
||||
// Allow write on the original func
|
||||
res = mprotect(originalFunctionPage, page_size()*2, PROT_READ|PROT_WRITE|PROT_EXEC);
|
||||
|
||||
// Write the jump to trampoline
|
||||
gen_immediate_jump(reinterpret_cast<uint8_t*>(*ppOriginalFunc), trampoline->hookJump);
|
||||
|
||||
// Remove write permission
|
||||
res = mprotect(originalFunctionPage, page_size()*2, PROT_READ|PROT_EXEC);
|
||||
|
||||
*ppOriginalFunc = (void*)(trampoline->trampolineBytes);
|
||||
}
|
||||
}
|
||||
cur_transaction.clear();
|
||||
transaction_started = false;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int Linux_Detour::unhook_func(void** ppOriginalFunc, void* _hook)
|
||||
{
|
||||
if( !transaction_started )
|
||||
return -EPERM;
|
||||
|
||||
if( ppOriginalFunc == nullptr || _hook == nullptr || *ppOriginalFunc == nullptr )
|
||||
return -EINVAL;
|
||||
|
||||
trampoline_t *trampoline = reinterpret_cast<trampoline_t*>(*ppOriginalFunc);
|
||||
void *page_start = page_addr(reinterpret_cast<void*>(trampoline), page_size());
|
||||
auto it = std::find_if(trampoline_regions.begin(), trampoline_regions.end(), [page_start](trampoline_region_t ®ion){
|
||||
if( is_page_inside_region(page_start, region) )
|
||||
return true;
|
||||
return false;
|
||||
});
|
||||
if( it != trampoline_regions.end() )
|
||||
{
|
||||
cur_transaction.push_back({true, ppOriginalFunc, trampoline});
|
||||
}
|
||||
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
int Linux_Detour::hook_func(void** ppOriginalFunc, void* _hook)
|
||||
{
|
||||
if( !transaction_started )
|
||||
return -EPERM;
|
||||
|
||||
if( ppOriginalFunc == nullptr || _hook == nullptr || *ppOriginalFunc == nullptr )
|
||||
return -EINVAL;
|
||||
|
||||
uint8_t* hook = reinterpret_cast<uint8_t*>(_hook);
|
||||
uint8_t* pOriginalFunc = reinterpret_cast<uint8_t*>(*ppOriginalFunc);
|
||||
int code_len = find_space_for_trampoline(pOriginalFunc, relative_jump_size);
|
||||
|
||||
if( code_len < relative_jump_size )
|
||||
return -ENOSPC;
|
||||
|
||||
// Allocate the trampoline, try to put it right in the middle of the mem, so a relative jump can access any function in the app (+/-2GB)
|
||||
//
|
||||
// Our hook is a 5 bytes JMP (1 bytes for opcode, 4 for RELATIVE jump)
|
||||
// /!\ TODO: Add checks on JMP overflow
|
||||
|
||||
trampoline_t *trampoline = get_free_trampoline();
|
||||
uint8_t *pTrampolineCode = trampoline->trampolineBytes;
|
||||
|
||||
void* trampoline_page = page_addr(reinterpret_cast<void*>(trampoline), page_size());
|
||||
|
||||
// Enable write to the trampoline region
|
||||
mprotect(trampoline_page, page_size()*2, PROT_READ|PROT_WRITE|PROT_EXEC);
|
||||
// Create relative jmp to hook
|
||||
gen_immediate_jump(trampoline->hookJump, hook);
|
||||
// Copy original opcodes
|
||||
trampoline->nOriginalBytes = code_len;
|
||||
std::copy((uint8_t*)pOriginalFunc, ((uint8_t*)pOriginalFunc)+code_len, trampoline->originalBytes);
|
||||
std::copy((uint8_t*)pOriginalFunc, ((uint8_t*)pOriginalFunc)+code_len, pTrampolineCode);
|
||||
pTrampolineCode += code_len;
|
||||
// Create the relative jmp to original (function + backed up opcodes)
|
||||
pTrampolineCode = gen_immediate_jump(pTrampolineCode, pOriginalFunc+code_len);
|
||||
pTrampolineCode += relative_addr_jump_size;
|
||||
|
||||
// Disable trampoline region write
|
||||
mprotect(trampoline_page, page_size()*2, PROT_READ|PROT_EXEC);
|
||||
|
||||
cur_transaction.push_back({false, ppOriginalFunc, trampoline});
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* ------ DOCUMENTATION ------
|
||||
http://www.c-jump.com/CIS77/CPU/x86/lecture.html <- some help to understand [MOD][REG][R/M] (see paragraph #6)
|
||||
http://shell-storm.org/online/Online-Assembler-and-Disassembler <- online assembler
|
||||
http://ref.x86asm.net/coder32.html <- opcodes reference
|
||||
|
||||
X86
|
||||
|
||||
push ebx : 0x53
|
||||
sub esp ?? : 0x83 0xEC 0x??
|
||||
call ????????: 0xE8 0x?? 0x?? 0x?? 0x??
|
||||
|
||||
|
||||
// relative jmp: ???????? = dst_addr - curr_addr - 5
|
||||
jmp ???????? : 0xe9 0x?? 0x?? 0x?? 0x??
|
||||
destination = 0x8dba8
|
||||
jmp location: 0x91995 - opcodes: e9 0e c2 ff ff
|
||||
0e c2 ff ff = 0x8dba8 - 0x91995 - 5
|
||||
|
||||
// short jmp: ?? = dst_addr - curr_addr - 2
|
||||
jmp short ??: 0xeb 0x??
|
||||
destination = 0x91964
|
||||
jmp location: 0x9198f - opcodes: 0xeb 0xd3
|
||||
d3 = 0x91964 - 0x9198f - 2
|
||||
|
||||
X64
|
||||
|
||||
TODO:
|
||||
Hint: make relative jump to near (+/-2Gb) code : 5 bytes
|
||||
load absolute addr into R11 and call a jmp on register R11 : 13 bytes
|
||||
Or
|
||||
Reuse x86 relative jmp method
|
||||
|
||||
Example:
|
||||
mov r11, 0x0123456789abcdef -> 0x49 0xbb 0xef 0xcd 0xab 0x89 0x67 0x45 0x23 0x01
|
||||
jmp r11 -> 0x41 0xff 0xe3
|
||||
|
||||
|
||||
*/
|
||||
32
overlay_experimental/Linux_Detour.h
Normal file
32
overlay_experimental/Linux_Detour.h
Normal file
|
|
@ -0,0 +1,32 @@
|
|||
#ifndef LINUX_DETOUR_H
|
||||
#define LINUX_DETOUR_H
|
||||
|
||||
#include <sys/syscall.h>
|
||||
#include <unistd.h>
|
||||
#include <pthread.h>
|
||||
#include <thread>
|
||||
|
||||
class Linux_Detour
|
||||
{
|
||||
public:
|
||||
static int update_thread(pthread_t thread_id);
|
||||
static int transaction_begin();
|
||||
static int transaction_abort();
|
||||
static int transaction_commit();
|
||||
static int hook_func(void** ppOriginalFunc, void* _hook);
|
||||
static int unhook_func(void** ppOriginalFunc, void* _hook);
|
||||
|
||||
private:
|
||||
static int hook_func_abs(void** ppOriginalFunc, void* _hook);
|
||||
static int hook_func_rel(void** ppOriginalFunc, void* _hook);
|
||||
|
||||
Linux_Detour() = delete;
|
||||
Linux_Detour(Linux_Detour const&) = delete;
|
||||
Linux_Detour(Linux_Detour &&) = delete;
|
||||
Linux_Detour& operator=(Linux_Detour const&) = delete;
|
||||
Linux_Detour& operator=(Linux_Detour &&) = delete;
|
||||
};
|
||||
|
||||
extern "C" void *elf_hook(char const *library_filename, void const *library_address, char const *function_name, void const *substitution_address);
|
||||
|
||||
#endif // LINUX_DETOUR_H
|
||||
Loading…
Reference in a new issue