/* Mach-O compact unwind encoding.
Copyright (C) 2014-2020 Free Software Foundation, Inc.
This file is part of BFD, the Binary File Descriptor library.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#ifndef _MACH_O_UNWIND_H
#define _MACH_O_UNWIND_H
/* Encodings bits for all cpus. */
#define MACH_O_UNWIND_IS_NOT_FUNCTION_START 0x80000000
#define MACH_O_UNWIND_HAS_LSDA 0x40000000
#define MACH_O_UNWIND_PERSONALITY_MASK 0x30000000
#define MACH_O_UNWIND_PERSONALITY_SHIFT 28
/* Encodings for x86-64. */
/* Kind of encoding (4 bits). */
#define MACH_O_UNWIND_X86_64_MODE_MASK 0x0f000000
/* Frame is RBP based, using the standard sequence: push %rbp; mov %rsp, %rbp.
Non-volatile registers must be saved in the stack starting at %rbp-8 to
%rbp-2040 (offset is encoded in offset bits * 8). Registers saved are
encoded in registers bits, 3 bits per register. */
#define MACH_O_UNWIND_X86_64_MODE_RBP_FRAME 0x01000000
#define MACH_O_UNWIND_X86_64_RBP_FRAME_REGISTERS 0x00007FFF
#define MACH_O_UNWIND_X86_64_RBP_FRAME_OFFSET 0x00FF0000
/* Frameless function, with a small stack size. */
#define MACH_O_UNWIND_X86_64_MODE_STACK_IMMD 0x02000000
#define MACH_O_UNWIND_X86_64_FRAMELESS_STACK_SIZE 0x00FF0000
#define MACH_O_UNWIND_X86_64_FRAMELESS_REG_COUNT 0x00001C00
#define MACH_O_UNWIND_X86_64_FRAMELESS_REG_PERMUTATION 0x000003FF
/* Frameless function, with a larger stack size. The stack size is the sum
of the X in subq $X,%rsp (address of X is at function + stack size bits)
and stack adjust. */
#define MACH_O_UNWIND_X86_64_MODE_STACK_IND 0x03000000
#define MACH_O_UNWIND_X86_64_FRAMELESS_STACK_ADJUST 0x0000E000
/* Use dwarf. */
#define MACH_O_UNWIND_X86_64_MODE_DWARF 0x04000000
#define MACH_O_UNWIND_X86_64_DWARF_SECTION_OFFSET 0x00ffffff
/* Registers. */
#define MACH_O_UNWIND_X86_64_REG_NONE 0
#define MACH_O_UNWIND_X86_64_REG_RBX 1
#define MACH_O_UNWIND_X86_64_REG_R12 2
#define MACH_O_UNWIND_X86_64_REG_R13 3
#define MACH_O_UNWIND_X86_64_REG_R14 4
#define MACH_O_UNWIND_X86_64_REG_R15 5
#define MACH_O_UNWIND_X86_64_REG_RBP 6
/* Encodings for x86 (almot the same as x86-64). */
/* Kind of encoding (4 bits). */
#define MACH_O_UNWIND_X86_MODE_MASK 0x0f000000
/* Frame is EBP based, using the standard sequence: push %ebp; mov %esp, %ebp.
Non-volatile registers must be saved in the stack starting at %ebp-4 to
%ebp-240 (offset is encoded in offset bits * 4). Registers saved are
encoded in registers bits, 3 bits per register. */
#define MACH_O_UNWIND_X86_MODE_EBP_FRAME 0x01000000
#define MACH_O_UNWIND_X86_EBP_FRAME_REGISTERS 0x00007FFF
#define MACH_O_UNWIND_X86_EBP_FRAME_OFFSET 0x00FF0000
/* Frameless function, with a small stack size. */
#define MACH_O_UNWIND_X86_MODE_STACK_IMMD 0x02000000
#define MACH_O_UNWIND_X86_FRAMELESS_STACK_SIZE 0x00FF0000
#define MACH_O_UNWIND_X86_FRAMELESS_REG_COUNT 0x00001C00
#define MACH_O_UNWIND_X86_FRAMELESS_REG_PERMUTATION 0x000003FF
/* Frameless function, with a larger stack size. The stack size is the sum
of the X in subq $X,%esp (address of X is at function + stack size bits)
and stack adjust. */
#define MACH_O_UNWIND_X86_MODE_STACK_IND 0x03000000
#define MACH_O_UNWIND_X86_FRAMELESS_STACK_ADJUST 0x0000E000
/* Use dwarf. */
#define MACH_O_UNWIND_X86_MODE_DWARF 0x04000000
#define MACH_O_UNWIND_X86_DWARF_SECTION_OFFSET 0x00ffffff
/* Registers. */
#define MACH_O_UNWIND_X86_REG_NONE 0
#define MACH_O_UNWIND_X86_REG_EBX 1
#define MACH_O_UNWIND_X86_REG_ECX 2
#define MACH_O_UNWIND_X86_REG_EDX 3
#define MACH_O_UNWIND_X86_REG_EDI 4
#define MACH_O_UNWIND_X86_REG_ESI 5
#define MACH_O_UNWIND_X86_REG_EBP 6
/* Encodings for arm64. */
#define MACH_O_UNWIND_ARM64_MODE_MASK 0x0f000000
/* Leaf function: FP/LR are *not* saved, none or some non-volatile registers
are saved, stack is allocated. The size of the frame (register saved and
memory) is encoded in STACK_SIZE in 16 byte units. */
#define MACH_O_UNWIND_ARM64_MODE_FRAMELESS 0x02000000
#define MACH_O_UNWIND_ARM64_MODE_DWARF 0x03000000
/* Standard frame: FP/LR are pushed, SP is copied to FP, then non-volatile
registers are saved. */
#define MACH_O_UNWIND_ARM64_MODE_FRAME 0x04000000
/* Registers (for FRAME). */
#define MACH_O_UNWIND_ARM64_FRAME_X19_X20_PAIR 0x00000001
#define MACH_O_UNWIND_ARM64_FRAME_X21_X22_PAIR 0x00000002
#define MACH_O_UNWIND_ARM64_FRAME_X23_X24_PAIR 0x00000004
#define MACH_O_UNWIND_ARM64_FRAME_X25_X26_PAIR 0x00000008
#define MACH_O_UNWIND_ARM64_FRAME_X27_X28_PAIR 0x00000010
#define MACH_O_UNWIND_ARM64_FRAME_D8_D9_PAIR 0x00000100
#define MACH_O_UNWIND_ARM64_FRAME_D10_D11_PAIR 0x00000200
#define MACH_O_UNWIND_ARM64_FRAME_D12_D13_PAIR 0x00000400
#define MACH_O_UNWIND_ARM64_FRAME_D14_D15_PAIR 0x00000800
#define MACH_O_UNWIND_ARM64_FRAMELESS_STACK_SIZE_MASK 0x00fff000
#define MACH_O_UNWIND_ARM64_DWARF_SECTION_OFFSET 0x00ffffff
/* Entry in object file (in __LD,__compact_unwind section). */
struct mach_o_compact_unwind_32
{
unsigned char start[4];
unsigned char length[4];
unsigned char encoding[4];
unsigned char personality[4];
unsigned char lsda[4];
};
struct mach_o_compact_unwind_64
{
unsigned char start[8];
unsigned char length[4];
unsigned char encoding[4];
unsigned char personality[8];
unsigned char lsda[8];
};
/* Header in images (in __TEXT,__unwind_info). */
#define MACH_O_UNWIND_SECTION_VERSION 1 /* Current verion in header. */
struct mach_o_unwind_info_header
{
unsigned char version[4]; /* Currently MACH_O_UNWIND_SECTION_VERSION. */
unsigned char encodings_array_offset[4];
unsigned char encodings_array_count[4];
unsigned char personality_array_offset[4];
unsigned char personality_array_count[4];
unsigned char index_offset[4];
unsigned char index_count[4];
/* Followed by:
- encodings array
These are the encodings shared, for index < encoding_array_count
- personality array
count given by personality_array_count
- index entries
count given by index_count
- lsda index entries
last offset given by lsda offset of last index_entry.
*/
};
struct mach_o_unwind_index_entry
{
unsigned char function_offset[4];
unsigned char second_level_offset[4];
unsigned char lsda_index_offset[4];
};
struct mach_o_unwind_lsda_index_entry
{
unsigned char function_offset[4];
unsigned char lsda_offset[4];
};
/* Second level index pages. */
#define MACH_O_UNWIND_SECOND_LEVEL_REGULAR 2
struct mach_o_unwind_regular_second_level_page_header
{
unsigned char kind[4];
unsigned char entry_page_offset[2];
unsigned char entry_count[2];
/* Array of entries. */
};
struct mach_o_unwind_regular_second_level_entry
{
unsigned char function_offset[4];
unsigned char encoding[4];
};
#define MACH_O_UNWIND_SECOND_LEVEL_COMPRESSED 3
struct mach_o_unwind_compressed_second_level_page_header
{
unsigned char kind[4];
unsigned char entry_page_offset[2];
unsigned char entry_count[2];
unsigned char encodings_offset[2];
unsigned char encodings_count[2];
/* Followed by entries array (one word, see below). */
/* Followed by (non-common) encodings array. */
};
/* Compressed entries are one word, containing function offset and encoding
index. */
#define MACH_O_UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET(en) \
((en) & 0x00FFFFFF)
#define MACH_O_UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX(en) \
(((en) >> 24) & 0xFF)
#endif /* _MACH_O_UNWIND_H */