Loading...
--- dyld/dyld-655.1/src/dyldInitialization.cpp
+++ dyld/dyld-239.3/src/dyldInitialization.cpp
@@ -67,23 +67,6 @@
#define POINTER_RELOC GENERIC_RELOC_VANILLA
#endif
-#ifndef BIND_OPCODE_THREADED
-#define BIND_OPCODE_THREADED 0xD0
-#endif
-
-#ifndef BIND_SUBOPCODE_THREADED_SET_BIND_ORDINAL_TABLE_SIZE_ULEB
-#define BIND_SUBOPCODE_THREADED_SET_BIND_ORDINAL_TABLE_SIZE_ULEB 0x00
-#endif
-
-#ifndef BIND_SUBOPCODE_THREADED_APPLY
-#define BIND_SUBOPCODE_THREADED_APPLY 0x01
-#endif
-
-
-#if __has_feature(ptrauth_calls)
-#include <ptrauth.h>
-#endif
-
#if TARGET_IPHONE_SIMULATOR
const dyld::SyscallHelpers* gSyscallHelpers = NULL;
@@ -132,50 +115,13 @@
for (uint32_t i = 0; i < cmd_count; ++i) {
if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
const struct macho_segment_command* segCmd = (struct macho_segment_command*)cmd;
- if ( (segCmd->fileoff == 0) && (segCmd->filesize != 0)) {
+ if ( strcmp(segCmd->segname, "__TEXT") == 0 ) {
return (uintptr_t)mh - segCmd->vmaddr;
}
}
cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
return 0;
-}
-
-inline uint64_t read_uleb128(const uint8_t*& p, const uint8_t* end) {
- uint64_t result = 0;
- int bit = 0;
- do {
- if (p == end)
- throw "malformed uleb128 extends beyond trie";
- uint64_t slice = *p & 0x7f;
-
- if (bit >= 64 || slice << bit >> bit != slice)
- throw "uleb128 too big for 64-bits";
- else {
- result |= (slice << bit);
- bit += 7;
- }
- }
- while (*p++ & 0x80);
- return result;
-}
-
-inline int64_t read_sleb128(const uint8_t*& p, const uint8_t* end)
-{
- int64_t result = 0;
- int bit = 0;
- uint8_t byte;
- do {
- if (p == end)
- throw "malformed sleb128";
- byte = *p++;
- result |= (((int64_t)(byte & 0x7f)) << bit);
- bit += 7;
- } while (byte & 0x80);
- // sign extend negative numbers
- if ( (byte & 0x40) != 0 )
- result |= (~0ULL) << bit;
- return result;
}
@@ -190,215 +136,7 @@
const uint32_t cmd_count = mh->ncmds;
const struct load_command* const cmds = (struct load_command*)(((char*)mh)+sizeof(macho_header));
const struct load_command* cmd = cmds;
-
- // First look for compressed info and use it if it exists.
- const struct macho_segment_command* linkEditSeg = NULL;
- const dyld_info_command* dyldInfoCmd = NULL;
- for (uint32_t i = 0; i < cmd_count; ++i) {
- switch (cmd->cmd) {
- case LC_SEGMENT_COMMAND:
- {
- const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
- if ( strcmp(seg->segname, "__LINKEDIT") == 0 )
- linkEditSeg = seg;
- break;
- }
- case LC_DYLD_INFO_ONLY:
- dyldInfoCmd = (struct dyld_info_command*)cmd;
- break;
- }
- if (dyldInfoCmd && linkEditSeg)
- break;
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
- if ( linkEditSeg == NULL )
- throw "dyld missing LINKEDIT";
-
- // Reset the iterator.
- cmd = cmds;
-
- auto getSegmentAtIndex = [cmd_count, cmds](unsigned segIndex) -> const struct macho_segment_command* {
- const struct load_command* cmd = cmds;
- for (uint32_t i = 0; i < cmd_count; ++i) {
- switch (cmd->cmd) {
- case LC_SEGMENT_COMMAND:
- if (!segIndex) {
- const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
- return seg;
- }
- --segIndex;
- break;
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
- throw "out of bounds command";
- return 0;
- };
-
- auto segActualLoadAddress = [&](unsigned segIndex) -> uintptr_t {
- const struct macho_segment_command* seg = getSegmentAtIndex(segIndex);
- return seg->vmaddr + slide;
- };
-
-#if __has_feature(ptrauth_calls)
- auto imageBaseAddress = [cmds, cmd_count]() -> uintptr_t {
- const struct load_command* cmd = cmds;
- for (uint32_t i = 0; i < cmd_count; ++i) {
- switch (cmd->cmd) {
- case LC_SEGMENT_COMMAND: {
- const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
- if ( (seg->fileoff == 0) && (seg->filesize != 0) )
- return seg->vmaddr;
- break;
- }
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
- return 0;
- };
-#endif
-
- if (dyldInfoCmd && (dyldInfoCmd->bind_size != 0) ) {
- if ( dyldInfoCmd->rebase_size != 0 )
- throw "unthreaded rebases are not supported";
-
- const uint8_t* linkEditBase = (uint8_t*)(linkEditSeg->vmaddr + slide - linkEditSeg->fileoff);
-
- const uint8_t* const start = linkEditBase + dyldInfoCmd->bind_off;
- const uint8_t* const end = &start[dyldInfoCmd->bind_size];
- const uint8_t* p = start;
-
- uintptr_t segmentStartAddress = 0;
- uint64_t segOffset = 0;
- int segIndex = 0;
-#if __has_feature(ptrauth_calls)
- uintptr_t fBaseAddress = imageBaseAddress();
-#endif
- bool done = false;
-
- while ( !done && (p < end) ) {
- uint8_t immediate = *p & BIND_IMMEDIATE_MASK;
- uint8_t opcode = *p & BIND_OPCODE_MASK;
- ++p;
- switch (opcode) {
- case BIND_OPCODE_DONE:
- done = true;
- break;
- case BIND_OPCODE_SET_DYLIB_ORDINAL_IMM:
- break;
- case BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB:
- break;
- case BIND_OPCODE_SET_DYLIB_SPECIAL_IMM:
- break;
- case BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM:
- while (*p != '\0')
- ++p;
- ++p;
- break;
- case BIND_OPCODE_SET_TYPE_IMM:
- break;
- case BIND_OPCODE_SET_ADDEND_SLEB:
- read_sleb128(p, end);
- break;
- case BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
- segIndex = immediate;
- segmentStartAddress = segActualLoadAddress(segIndex);
- segOffset = read_uleb128(p, end);
- break;
- case BIND_OPCODE_ADD_ADDR_ULEB:
- segOffset += read_uleb128(p, end);
- break;
- case BIND_OPCODE_DO_BIND:
- break;
- case BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB:
- break;
- case BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED:
- break;
- case BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB:
- read_uleb128(p, end);
- read_uleb128(p, end);
- break;
- case BIND_OPCODE_THREADED:
- // Note the immediate is a sub opcode
- switch (immediate) {
- case BIND_SUBOPCODE_THREADED_SET_BIND_ORDINAL_TABLE_SIZE_ULEB:
- read_uleb128(p, end);
- break;
- case BIND_SUBOPCODE_THREADED_APPLY: {
- uint64_t delta = 0;
- do {
- uintptr_t address = segmentStartAddress + (uintptr_t)segOffset;
- uint64_t value = *(uint64_t*)address;
-
-#if __has_feature(ptrauth_calls)
- uint16_t diversity = (uint16_t)(value >> 32);
- bool hasAddressDiversity = (value & (1ULL << 48)) != 0;
- ptrauth_key key = (ptrauth_key)((value >> 49) & 0x3);
- bool isAuthenticated = (value & (1ULL << 63)) != 0;
-#endif
- bool isRebase = (value & (1ULL << 62)) == 0;
- if (isRebase) {
-
-#if __has_feature(ptrauth_calls)
- if (isAuthenticated) {
- // The new value for a rebase is the low 32-bits of the threaded value plus the slide.
- uint64_t newValue = (value & 0xFFFFFFFF) + slide;
- // Add in the offset from the mach_header
- newValue += fBaseAddress;
- // We have bits to merge in to the discriminator
- uintptr_t discriminator = diversity;
- if (hasAddressDiversity) {
- // First calculate a new discriminator using the address of where we are trying to store the value
- discriminator = __builtin_ptrauth_blend_discriminator((void*)address, discriminator);
- }
- switch (key) {
- case ptrauth_key_asia:
- newValue = (uintptr_t)__builtin_ptrauth_sign_unauthenticated((void*)newValue, ptrauth_key_asia, discriminator);
- break;
- case ptrauth_key_asib:
- newValue = (uintptr_t)__builtin_ptrauth_sign_unauthenticated((void*)newValue, ptrauth_key_asib, discriminator);
- break;
- case ptrauth_key_asda:
- newValue = (uintptr_t)__builtin_ptrauth_sign_unauthenticated((void*)newValue, ptrauth_key_asda, discriminator);
- break;
- case ptrauth_key_asdb:
- newValue = (uintptr_t)__builtin_ptrauth_sign_unauthenticated((void*)newValue, ptrauth_key_asdb, discriminator);
- break;
- }
- *(uint64_t*)address = newValue;
- } else
-#endif
- {
- // Regular pointer which needs to fit in 51-bits of value.
- // C++ RTTI uses the top bit, so we'll allow the whole top-byte
- // and the signed-extended bottom 43-bits to be fit in to 51-bits.
- uint64_t top8Bits = value & 0x0007F80000000000ULL;
- uint64_t bottom43Bits = value & 0x000007FFFFFFFFFFULL;
- uint64_t targetValue = ( top8Bits << 13 ) | (((intptr_t)(bottom43Bits << 21) >> 21) & 0x00FFFFFFFFFFFFFF);
- targetValue = targetValue + slide;
- *(uint64_t*)address = targetValue;
- }
- }
-
- // The delta is bits [51..61]
- // And bit 62 is to tell us if we are a rebase (0) or bind (1)
- value &= ~(1ULL << 62);
- delta = ( value & 0x3FF8000000000000 ) >> 51;
- segOffset += delta * sizeof(uintptr_t);
- } while ( delta != 0 );
- break;
- }
- default:
- throw "unknown threaded bind subopcode";
- }
- break;
- default:
- throw "unknown bind opcode";
- }
- }
- return;
- }
-
+ const struct macho_segment_command* linkEditSeg = NULL;
#if __x86_64__
const struct macho_segment_command* firstWritableSeg = NULL;
#endif
@@ -408,13 +146,15 @@
case LC_SEGMENT_COMMAND:
{
const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ if ( strcmp(seg->segname, "__LINKEDIT") == 0 )
+ linkEditSeg = seg;
const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
const struct macho_section* const sectionsEnd = §ionsStart[seg->nsects];
for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
const uint8_t type = sect->flags & SECTION_TYPE;
if ( type == S_NON_LAZY_SYMBOL_POINTERS ) {
// rebase non-lazy pointers (which all point internal to dyld, since dyld uses no shared libraries)
- const uint32_t pointerCount = (uint32_t)(sect->size / sizeof(uintptr_t));
+ const uint32_t pointerCount = sect->size / sizeof(uintptr_t);
uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + slide);
for (uint32_t j=0; j < pointerCount; ++j) {
symbolPointers[j] += slide;
@@ -436,8 +176,6 @@
// use reloc's to rebase all random data pointers
#if __x86_64__
- if ( firstWritableSeg == NULL )
- throw "no writable segment in dyld";
const uintptr_t relocBase = firstWritableSeg->vmaddr + slide;
#else
const uintptr_t relocBase = (uintptr_t)mh;
@@ -471,14 +209,9 @@
{
// if kernel had to slide dyld, we need to fix up load sensitive locations
// we have to do this before using any global variables
- slide = slideOfMainExecutable(dyldsMachHeader);
- bool shouldRebase = slide != 0;
-#if __has_feature(ptrauth_calls)
- shouldRebase = true;
-#endif
- if ( shouldRebase ) {
- rebaseDyld(dyldsMachHeader, slide);
- }
+ if ( slide != 0 ) {
+ rebaseDyld(dyldsMachHeader, slide);
+ }
// allow dyld to use mach messaging
mach_init();