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--- dyld/dyld-360.19/src/dyldInitialization.cpp
+++ dyld/dyld-733.6/src/dyldInitialization.cpp
@@ -27,50 +27,23 @@
#include <stddef.h>
#include <string.h>
#include <stdlib.h>
-#include <Availability.h>
+#include <sys/mman.h>
#include <mach/mach.h>
-#include <mach-o/loader.h>
-#include <mach-o/ldsyms.h>
-#include <mach-o/reloc.h>
-#if __x86_64__
- #include <mach-o/x86_64/reloc.h>
-#endif
-#include "dyld.h"
+
+#include "dyld2.h"
#include "dyldSyscallInterface.h"
+#include "MachOAnalyzer.h"
+#include "Tracing.h"
-// from dyld_gdb.cpp
-extern void addImagesToAllImages(uint32_t infoCount, const dyld_image_info info[]);
+// from libc.a
+extern "C" void mach_init();
+extern "C" void __guard_setup(const char* apple[]);
+
+
+// from dyld_debugger.cpp
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 LC_SEGMENT_COMMAND LC_SEGMENT_64
- #define macho_segment_command segment_command_64
- #define macho_section section_64
- #define RELOC_SIZE 3
-#else
- #define LC_SEGMENT_COMMAND LC_SEGMENT
- #define macho_segment_command segment_command
- #define macho_section section
- #define RELOC_SIZE 2
-#endif
-
-#if __x86_64__
- #define POINTER_RELOC X86_64_RELOC_UNSIGNED
-#else
- #define POINTER_RELOC GENERIC_RELOC_VANILLA
-#endif
-
-
-#if TARGET_IPHONE_SIMULATOR
const dyld::SyscallHelpers* gSyscallHelpers = NULL;
-#endif
//
@@ -80,6 +53,9 @@
namespace dyldbootstrap {
+
+// currently dyld has no initializers, but if some come back, set this to non-zero
+#define DYLD_INITIALIZER_SUPPORT 0
#if DYLD_INITIALIZER_SUPPORT
@@ -95,7 +71,7 @@
// dyld (should be static) but is a dynamic executable and needs this hack to run its own initializers.
// We pass argc, argv, etc in case libc.a uses those arguments
//
-static void runDyldInitializers(const struct macho_header* mh, intptr_t slide, int argc, const char* argv[], const char* envp[], const char* apple[])
+static void runDyldInitializers(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);
@@ -105,116 +81,48 @@
//
-// The kernel may have slid a Position Independent Executable
+// On disk, all pointers in dyld's DATA segment are chained together.
+// They need to be fixed up to be real pointers to run.
//
-static uintptr_t slideOfMainExecutable(const struct macho_header* mh)
+static void rebaseDyld(const dyld3::MachOLoaded* dyldMH)
{
- 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 ( strcmp(segCmd->segname, "__TEXT") == 0 ) {
- return (uintptr_t)mh - segCmd->vmaddr;
- }
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
- return 0;
+ // walk all fixups chains and rebase dyld
+ const dyld3::MachOAnalyzer* ma = (dyld3::MachOAnalyzer*)dyldMH;
+ assert(ma->hasChainedFixups());
+ uintptr_t slide = (long)ma; // all fixup chain based images have a base address of zero, so slide == load address
+ __block Diagnostics diag;
+ ma->withChainStarts(diag, 0, ^(const dyld_chained_starts_in_image* starts) {
+ ma->fixupAllChainedFixups(diag, starts, slide, dyld3::Array<const void*>(), nullptr);
+ });
+ diag.assertNoError();
+
+ // now that rebasing done, initialize mach/syscall layer
+ mach_init();
+
+ // <rdar://47805386> mark __DATA_CONST segment in dyld as read-only (once fixups are done)
+ ma->forEachSegment(^(const dyld3::MachOFile::SegmentInfo& info, bool& stop) {
+ if ( info.readOnlyData ) {
+ ::mprotect(((uint8_t*)(dyldMH))+info.vmAddr, (size_t)info.vmSize, VM_PROT_READ);
+ }
+ });
}
-
-//
-// 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));
- uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + slide);
- for (uint32_t j=0; j < pointerCount; ++j) {
- symbolPointers[j] += slide;
- }
- }
- }
-#if __x86_64__
- if ( (firstWritableSeg == NULL) && (seg->initprot & VM_PROT_WRITE) )
- firstWritableSeg = seg;
-#endif
- }
- break;
- case LC_DYSYMTAB:
- dynamicSymbolTable = (struct dysymtab_command *)cmd;
- break;
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
-
- // use reloc's to rebase all random data pointers
-#if __x86_64__
- const uintptr_t relocBase = firstWritableSeg->vmaddr + slide;
-#else
- const uintptr_t relocBase = (uintptr_t)mh;
-#endif
- 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 ( reloc->r_length != RELOC_SIZE )
- throw "relocation in dyld has wrong size";
-
- if ( reloc->r_type != POINTER_RELOC )
- throw "relocation in dyld has wrong type";
-
- // update pointer by amount dyld slid
- *((uintptr_t*)(reloc->r_address + relocBase)) += slide;
- }
-}
-
-
-extern "C" void mach_init();
-extern "C" void __guard_setup(const char* apple[]);
//
// 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 dyld3::MachOLoaded* appsMachHeader, int argc, const char* argv[],
+ const dyld3::MachOLoaded* dyldsMachHeader, uintptr_t* startGlue)
{
+
+ // Emit kdebug tracepoint to indicate dyld bootstrap has started <rdar://46878536>
+ dyld3::kdebug_trace_dyld_marker(DBG_DYLD_TIMING_BOOTSTRAP_START, 0, 0, 0, 0);
+
// if kernel had to slide dyld, we need to fix up load sensitive locations
// we have to do this before using any global variables
- if ( slide != 0 ) {
- rebaseDyld(dyldsMachHeader, slide);
- }
-
- // allow dyld to use mach messaging
- mach_init();
+ rebaseDyld(dyldsMachHeader);
// kernel sets up env pointer to be just past end of agv array
const char** envp = &argv[argc+1];
@@ -229,37 +137,31 @@
#if DYLD_INITIALIZER_SUPPORT
// run all C++ initializers inside dyld
- runDyldInitializers(dyldsMachHeader, slide, argc, argv, envp, apple);
+ runDyldInitializers(argc, argv, envp, apple);
#endif
// 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);
+ uintptr_t appsSlide = appsMachHeader->getSlide();
+ return dyld::_main((macho_header*)appsMachHeader, appsSlide, argc, argv, envp, apple, startGlue);
}
-#if TARGET_IPHONE_SIMULATOR
+#if TARGET_OS_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 dyld3::MachOLoaded* mainExecutableMH, const dyld3::MachOLoaded* 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 dyld3::MachOLoaded* mainExecutableMH, const dyld3::MachOLoaded* dyldSimMH, 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;
- // save table of syscall pointers
- gSyscallHelpers = sc;
-
- // allow dyld to use mach messaging
- mach_init();
+ // dyld_sim uses chained rebases, so it always need to be fixed up
+ rebaseDyld(dyldSimMH);
// set up random value for stack canary
__guard_setup(apple);
@@ -269,8 +171,8 @@
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);
+ uintptr_t appsSlide = mainExecutableMH->getSlide();
+ return dyld::_main((macho_header*)mainExecutableMH, appsSlide, argc, argv, envp, apple, startGlue);
}
#endif