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--- dyld/dyld-625.13/src/dyldInitialization.cpp
+++ dyld/dyld-95.3/src/dyldInitialization.cpp
@@ -1,6 +1,6 @@
/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
*
- * Copyright (c) 2004-2008 Apple Inc. All rights reserved.
+ * Copyright (c) 2004-2005 Apple Computer, Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
@@ -27,34 +27,31 @@
#include <stddef.h>
#include <string.h>
#include <stdlib.h>
-#include <Availability.h>
#include <mach/mach.h>
#include <mach-o/loader.h>
#include <mach-o/ldsyms.h>
#include <mach-o/reloc.h>
+#if __ppc__ || __ppc64__
+ #include <mach-o/ppc/reloc.h>
+#endif
#if __x86_64__
#include <mach-o/x86_64/reloc.h>
#endif
#include "dyld.h"
-#include "dyldSyscallInterface.h"
-
-// from dyld_gdb.cpp
-extern void addImagesToAllImages(uint32_t infoCount, const dyld_image_info info[]);
-extern void syncProcessInfo();
#ifndef MH_PIE
#define MH_PIE 0x200000
#endif
-// currently dyld has no initializers, but if some come back, set this to non-zero
-#define DYLD_INITIALIZER_SUPPORT 0
#if __LP64__
+ #define macho_header mach_header_64
#define LC_SEGMENT_COMMAND LC_SEGMENT_64
#define macho_segment_command segment_command_64
#define macho_section section_64
#define RELOC_SIZE 3
#else
+ #define macho_header mach_header
#define LC_SEGMENT_COMMAND LC_SEGMENT
#define macho_segment_command segment_command
#define macho_section section
@@ -67,27 +64,8 @@
#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;
-#endif
+// from dyld.cpp
+namespace dyld { extern bool isRosetta(); };
//
@@ -98,13 +76,7 @@
namespace dyldbootstrap {
-
-#if DYLD_INITIALIZER_SUPPORT
-
typedef void (*Initializer)(int argc, const char* argv[], const char* envp[], const char* apple[]);
-
-extern const Initializer inits_start __asm("section$start$__DATA$__mod_init_func");
-extern const Initializer inits_end __asm("section$end$__DATA$__mod_init_func");
//
// For a regular executable, the crt code calls dyld to run the executables initializers.
@@ -114,295 +86,9 @@
//
static void runDyldInitializers(const struct macho_header* mh, intptr_t slide, int argc, const char* argv[], const char* envp[], const char* apple[])
{
- for (const Initializer* p = &inits_start; p < &inits_end; ++p) {
- (*p)(argc, argv, envp, apple);
- }
-}
-#endif // DYLD_INITIALIZER_SUPPORT
-
-
-//
-// The kernel may have slid a Position Independent Executable
-//
-static uintptr_t slideOfMainExecutable(const struct macho_header* mh)
-{
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;
- 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)) {
- 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;
-}
-
-
-//
-// If the kernel does not load dyld at its preferred address, we need to apply
-// fixups to various initialized parts of the __DATA segment
-//
-static void rebaseDyld(const struct macho_header* mh, intptr_t slide)
-{
- // rebase non-lazy pointers (which all point internal to dyld, since dyld uses no shared libraries)
- // and get interesting pointers into dyld
- 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;
- }
-
-#if __x86_64__
- const struct macho_segment_command* firstWritableSeg = NULL;
-#endif
- const struct dysymtab_command* dynamicSymbolTable = NULL;
for (uint32_t i = 0; i < cmd_count; ++i) {
switch (cmd->cmd) {
case LC_SEGMENT_COMMAND:
@@ -412,9 +98,52 @@
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_MOD_INIT_FUNC_POINTERS ){
+ Initializer* inits = (Initializer*)(sect->addr + slide);
+ const uint32_t count = sect->size / sizeof(uintptr_t);
+ for (uint32_t i=0; i < count; ++i) {
+ Initializer func = inits[i];
+ func(argc, argv, envp, apple);
+ }
+ }
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+}
+
+//
+// If the kernel does not load dyld at its preferred address, we need to apply
+// fixups to various initialized parts of the __DATA segment
+//
+static void rebaseDyld(const struct macho_header* mh, intptr_t slide)
+{
+ // rebase non-lazy pointers (which all point internal to dyld, since dyld uses no shared libraries)
+ // and get interesting pointers into dyld
+ 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;
+ const struct macho_segment_command* linkEditSeg = NULL;
+#if __x86_64__
+ const struct macho_segment_command* firstWritableSeg = NULL;
+#endif
+ const struct dysymtab_command* dynamicSymbolTable = 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;
+ 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 +165,6 @@
// 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;
@@ -445,6 +172,10 @@
const relocation_info* const relocsStart = (struct relocation_info*)(linkEditSeg->vmaddr + slide + dynamicSymbolTable->locreloff - linkEditSeg->fileoff);
const relocation_info* const relocsEnd = &relocsStart[dynamicSymbolTable->nlocrel];
for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+ #if __ppc__ || __ppc64__ || __i36__
+ if ( (reloc->r_address & R_SCATTERED) != 0 )
+ throw "scattered relocation in dyld";
+ #endif
if ( reloc->r_length != RELOC_SIZE )
throw "relocation in dyld has wrong size";
@@ -457,32 +188,171 @@
}
+//
+// For some reason the kernel loads dyld with __TEXT and __LINKEDIT writable
+// rdar://problem/3702311
+//
+static void segmentProtectDyld(const struct macho_header* mh, intptr_t slide)
+{
+ 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;
+ 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;
+ vm_address_t addr = seg->vmaddr + slide;
+ vm_size_t size = seg->vmsize;
+ const bool setCurrentPermissions = false;
+ vm_protect(mach_task_self(), addr, size, setCurrentPermissions, seg->initprot);
+ //dyld::log("dyld: segment %s, 0x%08X -> 0x%08X, set to %d\n", seg->segname, addr, addr+size-1, seg->initprot);
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+
+}
+
+
+//
+// re-map the main executable to a new random address
+//
+static const struct mach_header* randomizeExecutableLoadAddress(const struct mach_header* orgMH, uintptr_t* appsSlide)
+{
+#if __ppc__
+ // don't slide PIE programs running under rosetta
+ if ( dyld::isRosetta() )
+ return orgMH;
+#endif
+ // count segments
+ uint32_t segCount = 0;
+ const uint32_t cmd_count = orgMH->ncmds;
+ const struct load_command* const cmds = (struct load_command*)(((char*)orgMH)+sizeof(macho_header));
+ const struct load_command* cmd = cmds;
+ 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;
+ // page-zero and custom stacks don't move
+ if ( (strcmp(segCmd->segname, "__PAGEZERO") != 0) && (strcmp(segCmd->segname, "__UNIXSTACK") != 0) )
+ ++segCount;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+
+ // make copy of segment info
+ macho_segment_command segs[segCount];
+ uint32_t index = 0;
+ uintptr_t highestAddressUsed = 0;
+ uintptr_t lowestAddressUsed = UINTPTR_MAX;
+ cmd = cmds;
+ 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 ( (strcmp(segCmd->segname, "__PAGEZERO") != 0) && (strcmp(segCmd->segname, "__UNIXSTACK") != 0) ) {
+ segs[index++] = *segCmd;
+ if ( (segCmd->vmaddr + segCmd->vmsize) > highestAddressUsed )
+ highestAddressUsed = ((segCmd->vmaddr + segCmd->vmsize) + 4095) & -4096;
+ if ( segCmd->vmaddr < lowestAddressUsed )
+ lowestAddressUsed = segCmd->vmaddr;
+ // do nothing if kernel has already randomized load address
+ if ( (strcmp(segCmd->segname, "__TEXT") == 0) && (segCmd->vmaddr != (uintptr_t)orgMH) )
+ return orgMH;
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+
+ // choose a random new base address
+#if __LP64__
+ uintptr_t highestAddressPossible = highestAddressUsed + 0x100000000ULL;
+#else
+ uintptr_t highestAddressPossible = 0x80000000;
+#endif
+ uintptr_t sizeNeeded = highestAddressUsed-lowestAddressUsed;
+ if ( (highestAddressPossible-sizeNeeded) < highestAddressUsed ) {
+ // new and old segments will overlap
+ // need better algorithm for remapping
+ // punt and don't re-map
+ return orgMH;
+ }
+ uintptr_t possibleRange = (highestAddressPossible-sizeNeeded) - highestAddressUsed;
+ uintptr_t newBaseAddress = highestAddressUsed + ((arc4random() % possibleRange) & -4096);
+
+ vm_address_t addr = newBaseAddress;
+ // reserve new address range
+ if ( vm_allocate(mach_task_self(), &addr, sizeNeeded, VM_FLAGS_FIXED) == KERN_SUCCESS ) {
+ // copy each segment to new address
+ for (uint32_t i = 0; i < segCount; ++i) {
+ uintptr_t newSegAddress = segs[i].vmaddr - lowestAddressUsed + newBaseAddress;
+ if ( (vm_copy(mach_task_self(), segs[i].vmaddr, segs[i].vmsize, newSegAddress) != KERN_SUCCESS)
+ || (vm_protect(mach_task_self(), newSegAddress, segs[i].vmsize, true, segs[i].maxprot) != KERN_SUCCESS)
+ || (vm_protect(mach_task_self(), newSegAddress, segs[i].vmsize, false, segs[i].initprot) != KERN_SUCCESS) ) {
+ // can't copy so dealloc new region and run with original base address
+ vm_deallocate(mach_task_self(), newBaseAddress, sizeNeeded);
+ dyld::warn("could not relocate position independent exectable\n");
+ return orgMH;
+ }
+ }
+ // unmap original segments
+ vm_deallocate(mach_task_self(), lowestAddressUsed, highestAddressUsed-lowestAddressUsed);
+
+ // run with newly mapped executable
+ *appsSlide = newBaseAddress - lowestAddressUsed;
+ return (const struct mach_header*)newBaseAddress;
+ }
+
+ // can't get new range, so don't slide to random address
+ return orgMH;
+}
+
+
+extern "C" void dyld_exceptions_init(const struct macho_header*, uintptr_t slide); // in dyldExceptions.cpp
extern "C" void mach_init();
-extern "C" void __guard_setup(const char* apple[]);
+
+//
+// _pthread_keys is partitioned in a lower part that dyld will use; libSystem
+// will use the upper part. We set __pthread_tsd_first to 1 as the start of
+// the lower part. Libc will take #1 and c++ exceptions will take #2. There
+// is one free key=3 left.
+//
+extern "C" {
+ extern int __pthread_tsd_first;
+ extern void _pthread_keys_init();
+}
//
// This is code to bootstrap dyld. This work in normally done for a program by dyld and crt.
// In dyld we have to do this manually.
//
-uintptr_t start(const struct macho_header* appsMachHeader, int argc, const char* argv[],
- intptr_t slide, const struct macho_header* dyldsMachHeader,
- uintptr_t* startGlue)
-{
+uintptr_t start(const struct mach_header* appsMachHeader, int argc, const char* argv[], intptr_t slide)
+{
+ // _mh_dylinker_header is magic symbol defined by static linker (ld), see <mach-o/ldsyms.h>
+ const struct macho_header* dyldsMachHeader = (const struct macho_header*)(((char*)&_mh_dylinker_header)+slide);
+
// 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);
+ }
+
+ uintptr_t appsSlide = 0;
+
+ // set pthread keys to dyld range
+ __pthread_tsd_first = 1;
+ _pthread_keys_init();
+
+ // enable C++ exceptions to work inside dyld
+ dyld_exceptions_init(dyldsMachHeader, slide);
+
// allow dyld to use mach messaging
mach_init();
+ // set protection on segments (has to be done after mach_init)
+ segmentProtectDyld(dyldsMachHeader, slide);
+
// kernel sets up env pointer to be just past end of agv array
const char** envp = &argv[argc+1];
@@ -491,55 +361,18 @@
while(*apple != NULL) { ++apple; }
++apple;
- // set up random value for stack canary
- __guard_setup(apple);
-
-#if DYLD_INITIALIZER_SUPPORT
// run all C++ initializers inside dyld
runDyldInitializers(dyldsMachHeader, slide, argc, argv, envp, apple);
-#endif
-
+
+ // if main executable was linked -pie, then randomize its load address
+ if ( appsMachHeader->flags & MH_PIE )
+ appsMachHeader = randomizeExecutableLoadAddress(appsMachHeader, &appsSlide);
+
// now that we are done bootstrapping dyld, call dyld's main
- uintptr_t appsSlide = slideOfMainExecutable(appsMachHeader);
- return dyld::_main(appsMachHeader, appsSlide, argc, argv, envp, apple, startGlue);
-}
-
-
-#if TARGET_IPHONE_SIMULATOR
-
-extern "C" uintptr_t start_sim(int argc, const char* argv[], const char* envp[], const char* apple[],
- const macho_header* mainExecutableMH, const macho_header* dyldMH, uintptr_t dyldSlide,
- const dyld::SyscallHelpers*, uintptr_t* startGlue);
-
-
-uintptr_t start_sim(int argc, const char* argv[], const char* envp[], const char* apple[],
- const macho_header* mainExecutableMH, const macho_header* dyldMH, uintptr_t dyldSlide,
- const dyld::SyscallHelpers* sc, uintptr_t* startGlue)
-{
- // if simulator dyld loaded slid, it needs to rebase itself
- // we have to do this before using any global variables
- if ( dyldSlide != 0 ) {
- rebaseDyld(dyldMH, dyldSlide);
- }
-
- // save table of syscall pointers
- gSyscallHelpers = sc;
-
- // allow dyld to use mach messaging
- mach_init();
-
- // set up random value for stack canary
- __guard_setup(apple);
-
- // setup gProcessInfo to point to host dyld's struct
- dyld::gProcessInfo = (struct dyld_all_image_infos*)(sc->getProcessInfo());
- syncProcessInfo();
-
- // now that we are done bootstrapping dyld, call dyld's main
- uintptr_t appsSlide = slideOfMainExecutable(mainExecutableMH);
- return dyld::_main(mainExecutableMH, appsSlide, argc, argv, envp, apple, startGlue);
-}
-#endif
+ return dyld::_main(appsMachHeader, appsSlide, argc, argv, envp, apple);
+}
+
+
} // end of namespace