rizin/librz/bin/format/mach0/mach0_relocs.c

// SPDX-FileCopyrightText: 2021-2023 Florian Märkl <info@florianmaerkl.de>
// SPDX-FileCopyrightText: 2020 Francesco Tamagni <mrmacete@protonmail.ch>
// SPDX-FileCopyrightText: 2010-2020 nibble <nibble.ds@gmail.com>
// SPDX-FileCopyrightText: 2010-2020 pancake <pancake@nopcode.org>
// SPDX-License-Identifier: LGPL-3.0-only

#include <rz_util.h>
#include "mach0.h"
#include <ht_uu.h>

#include "mach0_utils.inc"

#define RELOCATION_INFO_SIZE 8 // sizeof(struct relocation_info)

/**
 * \param buf buffer of at least RELOCATION_INFO_SIZE bytes
 */
static void read_relocation_info(struct relocation_info *dst, ut8 *src, bool big_endian) {
	dst->r_address = (st32)rz_read_at_ble32(src, 0, big_endian);
	uint32_t field = rz_read_at_ble32(src, 4, big_endian);
	if (big_endian) {
		dst->r_type = field & rz_num_bitmask(4);
		field >>= 4;
		dst->r_extern = field & rz_num_bitmask(1);
		field >>= 1;
		dst->r_length = field & rz_num_bitmask(2);
		field >>= 2;
		dst->r_pcrel = field & rz_num_bitmask(1);
		field >>= 1;
		dst->r_symbolnum = field & rz_num_bitmask(24);
	} else {
		dst->r_symbolnum = field & rz_num_bitmask(24);
		field >>= 24;
		dst->r_pcrel = field & rz_num_bitmask(1);
		field >>= 1;
		dst->r_length = field & rz_num_bitmask(2);
		field >>= 2;
		dst->r_extern = field & rz_num_bitmask(1);
		field >>= 1;
		dst->r_type = field & rz_num_bitmask(4);
	}
}

static int reloc_comparator(struct reloc_t *a, struct reloc_t *b) {
	return a->addr - b->addr;
}

static void parse_relocation_info(struct MACH0_(obj_t) * bin, RzSkipList *relocs, ut32 offset, ut32 num) {
	if (!num || !offset || (st32)num < 0) {
		return;
	}

	ut64 total_size = (ut64)num * RELOCATION_INFO_SIZE;
	ut8 *infos = malloc(total_size);
	if (!infos) {
		return;
	}
	if (rz_buf_read_at(bin->b, offset, infos, total_size) < total_size) {
		free(infos);
		return;
	}

	size_t i;
	for (i = 0; i < num; i++) {
		struct relocation_info a_info;
		read_relocation_info(&a_info, infos + i * RELOCATION_INFO_SIZE, bin->big_endian);
		ut32 sym_num = a_info.r_symbolnum;
		if (sym_num >= bin->nsymtab) {
			continue;
		}

		ut32 stridx = bin->symtab[sym_num].n_strx;
		char *sym_name = MACH0_(get_name)(bin, stridx, false);
		if (!sym_name) {
			continue;
		}

		struct reloc_t *reloc = RZ_NEW0(struct reloc_t);
		if (!reloc) {
			free(infos);
			free(sym_name);
			return;
		}

		reloc->addr = MACH0_(paddr_to_vaddr)(bin, a_info.r_address);
		reloc->offset = a_info.r_address;
		reloc->ord = sym_num;
		reloc->type = a_info.r_type; // enum RelocationInfoType
		reloc->external = a_info.r_extern;
		reloc->pc_relative = a_info.r_pcrel;
		reloc->chained = false;
		reloc->size = 1 << a_info.r_length; // macho/reloc.h says: 0=byte, 1=word, 2=long, 3=quad
		rz_str_ncpy(reloc->name, sym_name, sizeof(reloc->name) - 1);
		rz_skiplist_insert(relocs, reloc);
		free(sym_name);
	}
	free(infos);
}

static bool is_valid_ordinal_table_size(ut64 size) {
	return size > 0 && size <= UT16_MAX;
}

static int parse_import_ptr(struct MACH0_(obj_t) * bin, struct reloc_t *reloc, int idx) {
	int i, j, sym;
	size_t wordsize;
	ut32 stype;
	wordsize = get_word_size(bin);
	if (idx < 0 || idx >= bin->nsymtab) {
		return 0;
	}
	if ((bin->symtab[idx].n_desc & REFERENCE_TYPE) == REFERENCE_FLAG_UNDEFINED_LAZY) {
		stype = S_LAZY_SYMBOL_POINTERS;
	} else {
		stype = S_NON_LAZY_SYMBOL_POINTERS;
	}

	reloc->offset = 0;
	reloc->addr = 0;
	reloc->addend = 0;
#define CASE(T) \
	case ((T) / 8): reloc->type = RZ_BIN_RELOC_##T; break
	switch (wordsize) {
		CASE(8);
		CASE(16);
		CASE(32);
		CASE(64);
	default: return false;
	}
#undef CASE

	for (i = 0; i < bin->nsects; i++) {
		if ((bin->sects[i].flags & SECTION_TYPE) == stype) {
			for (j = 0, sym = -1; bin->sects[i].reserved1 + j < bin->nindirectsyms; j++) {
				int indidx = bin->sects[i].reserved1 + j;
				if (indidx < 0 || indidx >= bin->nindirectsyms) {
					break;
				}
				if (idx == bin->indirectsyms[indidx]) {
					sym = j;
					break;
				}
			}
			reloc->offset = sym == -1 ? 0 : bin->sects[i].offset + sym * wordsize;
			reloc->addr = sym == -1 ? 0 : bin->sects[i].addr + sym * wordsize;
			return true;
		}
	}
	return false;
}

typedef struct {
	struct MACH0_(obj_t) * obj;
	RzSkipList *dst;
} FixupsAsRelocsCtx;

static void fixups_as_relocs_cb(struct mach0_chained_fixup_t *fixup, void *user) {
	FixupsAsRelocsCtx *ctx = user;
	struct reloc_t *reloc = RZ_NEW0(struct reloc_t);
	if (!reloc) {
		return;
	}
	reloc->offset = fixup->paddr;
	reloc->addr = ctx->obj->baddr + fixup->paddr;
	reloc->addend = fixup->addend;
	reloc->type = fixup->size == 4 ? RZ_BIN_RELOC_32 : RZ_BIN_RELOC_64;
	reloc->ord = fixup->is_bind ? fixup->bind_ordinal : -1;
	reloc->external = fixup->is_bind;
	reloc->chained = true;
	reloc->size = fixup->size;

	if (fixup->is_bind) {
		struct MACH0_(chained_import_t) import;
		if (MACH0_(get_chained_import)(ctx->obj, fixup->bind_ordinal, &import)) {
			char *name = MACH0_(chained_import_read_symbol_name)(ctx->obj, &import);
			if (name) {
				strncpy(reloc->name, name, sizeof(reloc->name) - 1);
				free(name);
			}
		}
	}

	rz_skiplist_insert(ctx->dst, reloc);
}

static void parse_relocs_from_chained_fixups(RzSkipList *dst, struct MACH0_(obj_t) * bin) {
	FixupsAsRelocsCtx ctx = {
		.obj = bin,
		.dst = dst
	};
	// clang-format off
	MACH0_(chained_fixups_foreach)(bin, fixups_as_relocs_cb, &ctx);
	// clang-format on
}

RZ_API void MACH0_(bind_opcodes_foreach)(struct MACH0_(obj_t) * bin,
	RZ_NONNULL BindOpcodesThreadedTableSizeCb threaded_table_size_cb,
	RZ_NULLABLE BindOpcodesBindCb do_bind_cb,
	RZ_NONNULL BindOpcodesThreadedApplyCb threaded_apply_cb,
	void *user) {
	if (!bin->dyld_info) {
		return;
	}
	ut8 *opcodes, rel_type = 0;
	size_t bind_size, lazy_size, weak_size;
	size_t wordsize = get_word_size(bin);

#define CASE(T) \
	case ((T) / 8): rel_type = RZ_BIN_RELOC_##T; break
	switch (wordsize) {
		CASE(8);
		CASE(16);
		CASE(32);
		CASE(64);
	default: return;
	}
#undef CASE
	bind_size = bin->dyld_info->bind_size;
	lazy_size = bin->dyld_info->lazy_bind_size;
	weak_size = bin->dyld_info->weak_bind_size;

	if (!bind_size && !lazy_size) {
		return;
	}

	if ((bind_size + lazy_size) < 1) {
		return;
	}
	if (bin->dyld_info->bind_off > bin->size || bin->dyld_info->bind_off + bind_size > bin->size) {
		return;
	}
	if (bin->dyld_info->lazy_bind_off > bin->size ||
		bin->dyld_info->lazy_bind_off + lazy_size > bin->size) {
		return;
	}
	if (bin->dyld_info->bind_off + bind_size + lazy_size > bin->size) {
		return;
	}
	if (bin->dyld_info->weak_bind_off + weak_size > bin->size) {
		return;
	}
	ut64 amount = bind_size + lazy_size + weak_size;
	if (amount == 0 || amount > UT32_MAX) {
		return;
	}
	if (!bin->segs) {
		return;
	}
	opcodes = calloc(1, amount + 1);
	if (!opcodes) {
		return;
	}

	int len = rz_buf_read_at(bin->b, bin->dyld_info->bind_off, opcodes, bind_size);
	len += rz_buf_read_at(bin->b, bin->dyld_info->lazy_bind_off, opcodes + bind_size, lazy_size);
	len += rz_buf_read_at(bin->b, bin->dyld_info->weak_bind_off, opcodes + bind_size + lazy_size, weak_size);
	if (len < amount) {
		RZ_LOG_ERROR("Error: read (dyld_info bind) at 0x%08" PFMT64x "\n", (ut64)(size_t)bin->dyld_info->bind_off);
		RZ_FREE(opcodes);
		return;
	}

	bool is_threaded = false;
	size_t partition_sizes[] = { bind_size, lazy_size, weak_size };
	size_t pidx;
	int opcodes_offset = 0;
	for (pidx = 0; pidx < RZ_ARRAY_SIZE(partition_sizes); pidx++) {
		size_t partition_size = partition_sizes[pidx];

		ut8 type = 0;
		int lib_ord = 0, seg_idx = -1, sym_ord = -1;
		char *sym_name = NULL;
		size_t j, count, skip;
		st64 addend = 0;
		ut64 seg_off = 0;
		ut64 seg_size = bin->segs[0].vmsize;

		ut8 *p = opcodes + opcodes_offset;
		ut8 *end = p + partition_size;
		bool done = false;
		while (!done && p < end) {
			ut8 imm = *p & BIND_IMMEDIATE_MASK;
			ut8 op = *p & BIND_OPCODE_MASK;
			p++;
			switch (op) {
			case BIND_OPCODE_DONE: {
				bool in_lazy_binds = pidx == 1;
				if (!in_lazy_binds) {
					done = true;
				}
				break;
			}
			case BIND_OPCODE_THREADED: {
				switch (imm) {
				case BIND_SUBOPCODE_THREADED_SET_BIND_ORDINAL_TABLE_SIZE_ULEB: {
					is_threaded = true;
					if (!threaded_table_size_cb) {
						continue;
					}
					ut64 table_size = read_uleb128(&p, end);
					if (!is_valid_ordinal_table_size(table_size)) {
						RZ_LOG_ERROR("Error: BIND_SUBOPCODE_THREADED_SET_BIND_ORDINAL_TABLE_SIZE_ULEB size is wrong\n");
						break;
					}
					threaded_table_size_cb(table_size, user);
					sym_ord = 0;
					break;
				}
				case BIND_SUBOPCODE_THREADED_APPLY:
					if (threaded_apply_cb) {
						threaded_apply_cb(seg_idx, seg_off, user);
					}
					break;
				default:
					RZ_LOG_ERROR("Error: Unexpected BIND_OPCODE_THREADED sub-opcode: 0x%x\n", imm);
				}
				break;
			}
			case BIND_OPCODE_SET_DYLIB_ORDINAL_IMM:
				lib_ord = imm;
				break;
			case BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB:
				lib_ord = read_uleb128(&p, end);
				break;
			case BIND_OPCODE_SET_DYLIB_SPECIAL_IMM:
				lib_ord = imm ? (st8)(BIND_OPCODE_MASK | imm) : 0;
				break;
			case BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM: {
				sym_name = (char *)p;
				while (*p++ && p < end) {
					/* empty loop */
				}
				if (p == end) {
					// string not zero-terminated
					sym_name = NULL;
					break;
				}
				if (is_threaded) {
					break;
				}
				sym_ord = -1;
				if (bin->symtab && bin->dysymtab.nundefsym < UT16_MAX) {
					for (j = 0; j < bin->dysymtab.nundefsym; j++) {
						size_t stridx = 0;
						bool found = false;
						int iundefsym = bin->dysymtab.iundefsym;
						if (iundefsym >= 0 && iundefsym < bin->nsymtab) {
							int sidx = iundefsym + j;
							if (sidx < 0 || sidx >= bin->nsymtab) {
								continue;
							}
							stridx = bin->symtab[sidx].n_strx;
							if (stridx >= bin->symstrlen) {
								continue;
							}
							found = true;
						}
						if (found && !strcmp((const char *)bin->symstr + stridx, sym_name)) {
							sym_ord = j;
							break;
						}
					}
				}
				break;
			}
			case BIND_OPCODE_SET_TYPE_IMM:
				type = imm;
				break;
			case BIND_OPCODE_SET_ADDEND_SLEB:
				addend = rz_sleb128((const ut8 **)&p, end);
				break;
			case BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
				seg_idx = imm;
				if (seg_idx >= bin->nsegs) {
					RZ_LOG_ERROR("Error: BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB"
						     " has unexistent segment %d\n",
						seg_idx);
					goto beach;
				}
				seg_off = read_uleb128(&p, end);
				seg_size = bin->segs[seg_idx].vmsize;
				break;
			case BIND_OPCODE_ADD_ADDR_ULEB:
				seg_off += read_uleb128(&p, end);
				break;
#define DO_BIND() \
	do { \
		ut64 final_addend = addend; \
		ut64 vaddr = 0; \
		ut64 paddr = 0; \
		if (!is_threaded && seg_idx < 0) { \
			break; \
		} \
		if (seg_idx >= 0) { \
			vaddr = bin->segs[seg_idx].vmaddr + seg_off; \
			paddr = bin->segs[seg_idx].fileoff + seg_off; \
			if (type == BIND_TYPE_TEXT_PCREL32) { \
				final_addend = addend - (bin->baddr + vaddr); \
			} \
		} \
		do_bind_cb(paddr, vaddr, final_addend, rel_type, lib_ord, sym_ord, sym_name, user); \
	} while (0)
			case BIND_OPCODE_DO_BIND:
				if (!is_threaded && seg_off >= seg_size) {
					RZ_LOG_ERROR("Error: Malformed DO bind opcode 0x%" PFMT64x "\n", seg_off);
					goto beach;
				}
				DO_BIND();
				if (is_threaded) {
					sym_ord++;
				} else {
					seg_off += wordsize;
				}
				break;
			case BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB:
				if (seg_off >= seg_size) {
					RZ_LOG_ERROR("Error: Malformed ADDR ULEB bind opcode\n");
					goto beach;
				}
				DO_BIND();
				seg_off += read_uleb128(&p, end) + wordsize;
				break;
			case BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED:
				if (seg_off >= seg_size) {
					RZ_LOG_ERROR("Error: Malformed IMM SCALED bind opcode\n");
					goto beach;
				}
				DO_BIND();
				seg_off += (ut64)imm * (ut64)wordsize + wordsize;
				break;
			case BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB:
				count = read_uleb128(&p, end);
				skip = read_uleb128(&p, end);
				for (j = 0; j < count; j++) {
					if (seg_off >= seg_size) {
						RZ_LOG_ERROR("Error: Malformed ULEB TIMES bind opcode\n");
						goto beach;
					}
					DO_BIND();
					seg_off += skip + wordsize;
				}
				break;
#undef DO_BIND
			default:
				RZ_LOG_ERROR("Error: unknown bind opcode 0x%02x in dyld_info\n", *p);
				goto beach;
			}
		}

		opcodes_offset += partition_size;
	}

beach:
	RZ_FREE(opcodes);
}

typedef struct {
	struct MACH0_(obj_t) * bin;
	RzSkipList *dst;
} BindCommandsRelocsCtx;

static void threaded_table_size(ut64 table_size, void *user) {}

static void do_bind(ut64 paddr, ut64 vaddr, st64 addend, ut8 rel_type, int lib_ord, int sym_ord, const char *sym_name, void *user) {
	if (sym_ord < 0 && !sym_name) {
		return;
	}
	BindCommandsRelocsCtx *ctx = user;
	struct reloc_t *reloc = RZ_NEW0(struct reloc_t);
	reloc->addr = vaddr;
	reloc->offset = paddr;
	(void)lib_ord; // available, but currently unused info
	reloc->ord = sym_ord;
	reloc->type = rel_type;
	if (sym_name)
		rz_str_ncpy(reloc->name, sym_name, 256);
	rz_skiplist_insert(ctx->dst, reloc);
}

static void threaded_apply(int seg_idx, ut64 seg_off, void *user) {
	// This is handled in mach0_chained_fixups.c
	// We only consider classic non-threaded binds here
}

static void parse_relocs_from_bind_opcodes(RzSkipList *dst, struct MACH0_(obj_t) * bin) {
	BindCommandsRelocsCtx ctx = {
		.bin = bin,
		.dst = dst
	};
	// clang-format off
	MACH0_(bind_opcodes_foreach)(bin, threaded_table_size, do_bind, threaded_apply, &ctx);
	// clang-format on
}

static void parse_relocs_from_indirect_syms(RzSkipList *dst, struct MACH0_(obj_t) * bin) {
	if (!bin->symtab || !bin->symstr || !bin->sects || !bin->indirectsyms) {
		return;
	}
	int amount = bin->dysymtab.nundefsym;
	if (amount < 0) {
		amount = 0;
	}
	for (int j = 0; j < amount; j++) {
		struct reloc_t *reloc = RZ_NEW0(struct reloc_t);
		if (!reloc || !parse_import_ptr(bin, reloc, bin->dysymtab.iundefsym + j)) {
			free(reloc);
			break;
		}
		reloc->ord = j;
		RzSkipListNode *node = rz_skiplist_insert(dst, reloc);
		if (node->data != reloc) {
			free(reloc);
		}
	}
}

static void parse_relocs_from_extrels(RzSkipList *dst, struct MACH0_(obj_t) * bin) {
	if (!bin->symtab || !bin->dysymtab.extreloff || !bin->dysymtab.nextrel) {
		return;
	}
	parse_relocation_info(bin, dst, bin->dysymtab.extreloff, bin->dysymtab.nextrel);
}

RZ_BORROW RzSkipList /* struct reloc_t * */ *MACH0_(get_relocs)(struct MACH0_(obj_t) * bin) {
	rz_return_val_if_fail(bin, NULL);
	if (bin->relocs_parsed) {
		return bin->relocs;
	}
	bin->relocs_parsed = true;
	bin->relocs = rz_skiplist_new((RzListFree)&free, (RzListComparator)&reloc_comparator);
	if (!bin->relocs) {
		return NULL;
	}
	if (MACH0_(has_chained_fixups)(bin)) {
		parse_relocs_from_chained_fixups(bin->relocs, bin);
	} else {
		parse_relocs_from_bind_opcodes(bin->relocs, bin);
		parse_relocs_from_indirect_syms(bin->relocs, bin);
		parse_relocs_from_extrels(bin->relocs, bin);
	}
	return bin->relocs;
}

static RzPVector /*<struct reloc_t *>*/ *get_patchable_relocs(struct MACH0_(obj_t) * obj) {
	if (!obj->options.patch_relocs) {
		return NULL;
	}
	if (obj->patchable_relocs) {
		return obj->patchable_relocs;
	}
	RzSkipList *relocs = MACH0_(get_relocs)(obj);
	if (!relocs) {
		return NULL;
	}
	obj->patchable_relocs = rz_pvector_new(NULL);
	if (!obj->patchable_relocs) {
		return NULL;
	}
	RzSkipListNode *it;
	struct reloc_t *reloc;
	rz_skiplist_foreach (relocs, it, reloc) {
		if (!reloc->external) {
			// right now, we only care about patching external relocs
			// others might be interesting too in the future though, for example in object files.
			continue;
		}
		rz_pvector_push(obj->patchable_relocs, reloc);
	}
	return obj->patchable_relocs;
}

RZ_API bool MACH0_(needs_reloc_patching)(struct MACH0_(obj_t) * obj) {
	rz_return_val_if_fail(obj, false);
	RzPVector *patchable_relocs = get_patchable_relocs(obj);
	return patchable_relocs && rz_pvector_len(patchable_relocs);
}

RZ_API ut64 MACH0_(reloc_target_size)(struct MACH0_(obj_t) * obj) {
	int bits = MACH0_(get_bits_from_hdr)(&obj->hdr);
	if (bits) {
		return 8;
	}
	return bits / 8;
}

/// size of the artificial reloc target vfile
RZ_API ut64 MACH0_(reloc_targets_vfile_size)(struct MACH0_(obj_t) * obj) {
	RzPVector *patchable_relocs = get_patchable_relocs(obj);
	if (!patchable_relocs) {
		return 0;
	}
	return rz_pvector_len(patchable_relocs) * MACH0_(reloc_target_size)(obj);
}

/// base vaddr where to map the artificial reloc target vfile
RZ_API ut64 MACH0_(reloc_targets_map_base)(RzBinFile *bf, struct MACH0_(obj_t) * obj) {
	if (obj->reloc_targets_map_base_calculated) {
		return obj->reloc_targets_map_base;
	}
	RzList *maps = MACH0_(get_maps_unpatched)(bf);
	obj->reloc_targets_map_base = rz_bin_relocs_patch_find_targets_map_base(maps, MACH0_(reloc_target_size)(obj));
	rz_list_free(maps);
	obj->reloc_targets_map_base_calculated = true;
	return obj->reloc_targets_map_base;
}

static bool _patch_reloc(struct MACH0_(obj_t) * bin, struct reloc_t *reloc, ut64 symbol_at) {
	ut64 pc = reloc->addr;
	ut64 ins_len = 0;

	if (!reloc->chained) {
		switch (bin->hdr.cputype) {
		case CPU_TYPE_X86_64: {
			switch (reloc->type) {
			case X86_64_RELOC_UNSIGNED:
				break;
			case X86_64_RELOC_BRANCH:
				pc -= 1;
				ins_len = 5;
				break;
			default:
				RZ_LOG_ERROR("Warning: unsupported reloc type for X86_64 (%d), please file a bug.\n", reloc->type);
				return false;
			}
			break;
		}
		case CPU_TYPE_ARM64:
		case CPU_TYPE_ARM64_32:
			pc = reloc->addr & ~3;
			ins_len = 4;
			break;
		case CPU_TYPE_ARM:
			break;
		default:
			RZ_LOG_ERROR("Warning: unsupported architecture for patching relocs, please file a bug. %s\n", MACH0_(get_cputype_from_hdr)(&bin->hdr));
			return false;
		}
	}

	ut64 val = symbol_at;
	if (reloc->pc_relative) {
		val = symbol_at - pc - ins_len;
	}

	ut8 buf[8];
	rz_write_ble(buf, val, false, reloc->size * 8);
	rz_buf_write_at(bin->buf_patched, reloc->offset, buf, RZ_MIN(sizeof(buf), reloc->size));
	return true;
}

/**
 * \brief Patching of external relocs in a sparse overlay buffer
 *
 * This patches both classic Mach-O relocs and modern dyld chained pointers
 */
RZ_API void MACH0_(patch_relocs)(RzBinFile *bf, struct MACH0_(obj_t) * obj) {
	rz_return_if_fail(obj);
	if (obj->relocs_patched) {
		return;
	}
	bool needs_reloc_patch = MACH0_(needs_reloc_patching)(obj);
	bool needs_chained_patch = MACH0_(has_chained_fixups)(obj);
	if (obj->relocs_patched || (!needs_reloc_patch && !needs_chained_patch)) {
		return;
	}
	obj->relocs_patched = true; // run this function just once (lazy relocs patching)
	obj->buf_patched = rz_buf_new_sparse_overlay(obj->b, RZ_BUF_SPARSE_WRITE_MODE_SPARSE);
	if (!obj->buf_patched) {
		return;
	}

	if (needs_reloc_patch) {
		ut64 cdsz = MACH0_(reloc_target_size)(obj);
		ut64 size = MACH0_(reloc_targets_vfile_size)(obj);
		if (!size) {
			return;
		}
		RzBinRelocTargetBuilder *targets = rz_bin_reloc_target_builder_new(cdsz, MACH0_(reloc_targets_map_base)(bf, obj));
		if (!targets) {
			return;
		}
		RzPVector *patchable_relocs = get_patchable_relocs(obj);
		void **it;
		rz_pvector_foreach (patchable_relocs, it) {
			struct reloc_t *reloc = *it;
			ut64 sym_addr = rz_bin_reloc_target_builder_get_target(targets, reloc->ord);
			reloc->target = sym_addr;
			_patch_reloc(obj, reloc, sym_addr);
		}
		rz_bin_reloc_target_builder_free(targets);
	}

	if (needs_chained_patch) {
		// clang-format off
		MACH0_(patch_chained_fixups)(obj, obj->buf_patched);
		// clang-format on
	}

	// from now on, all writes should propagate through to the actual file
	rz_buf_sparse_set_write_mode(obj->buf_patched, RZ_BUF_SPARSE_WRITE_MODE_THROUGH);
}