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--- dyld/dyld-852.2/src/dyldInitialization.cpp
+++ dyld/dyld-360.18/src/dyldInitialization.cpp
@@ -27,35 +27,59 @@
#include <stddef.h>
#include <string.h>
#include <stdlib.h>
-#include <sys/mman.h>
+#include <Availability.h>
#include <mach/mach.h>
-
-#include "dyld2.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 "dyldSyscallInterface.h"
-#include "MachOAnalyzer.h"
-#include "Tracing.h"
-
-// from libc.a
-extern "C" void mach_init();
-extern "C" void __guard_setup(const char* apple[]);
-extern "C" void _subsystem_init(const char* apple[]);
-
-// from dyld_debugger.cpp
+
+// from dyld_gdb.cpp
+extern void addImagesToAllImages(uint32_t infoCount, const dyld_image_info info[]);
extern void syncProcessInfo();
-const dyld::SyscallHelpers* gSyscallHelpers = NULL;
-
-
-//
-// Code to bootstrap dyld into a runnable state
-//
-//
-
-namespace dyldbootstrap {
-
+#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
+
+
+//
+// Code to bootstrap dyld into a runnable state
+//
+//
+
+namespace dyldbootstrap {
+
#if DYLD_INITIALIZER_SUPPORT
@@ -71,7 +95,7 @@
// 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(int argc, const char* argv[], const char* envp[], const char* apple[])
+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);
@@ -81,48 +105,116 @@
//
-// 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 void rebaseDyld(const dyld3::MachOLoaded* dyldMH)
-{
- // 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);
- }
- });
-}
-
+// 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 ( strcmp(segCmd->segname, "__TEXT") == 0 ) {
+ return (uintptr_t)mh - segCmd->vmaddr;
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ return 0;
+}
+
+
+//
+// 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 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);
-
+uintptr_t start(const struct macho_header* appsMachHeader, int argc, const char* argv[],
+ intptr_t slide, const struct macho_header* dyldsMachHeader,
+ uintptr_t* startGlue)
+{
// if kernel had to slide dyld, we need to fix up load sensitive locations
// we have to do this before using any global variables
- rebaseDyld(dyldsMachHeader);
+ if ( slide != 0 ) {
+ rebaseDyld(dyldsMachHeader, slide);
+ }
+
+ // allow dyld to use mach messaging
+ mach_init();
// kernel sets up env pointer to be just past end of agv array
const char** envp = &argv[argc+1];
@@ -137,33 +229,37 @@
#if DYLD_INITIALIZER_SUPPORT
// run all C++ initializers inside dyld
- runDyldInitializers(argc, argv, envp, apple);
-#endif
-
- _subsystem_init(apple);
+ runDyldInitializers(dyldsMachHeader, slide, argc, argv, envp, apple);
+#endif
// now that we are done bootstrapping dyld, call dyld's main
- uintptr_t appsSlide = appsMachHeader->getSlide();
- return dyld::_main((macho_header*)appsMachHeader, appsSlide, argc, argv, envp, apple, startGlue);
-}
-
-
-#if TARGET_OS_SIMULATOR
+ 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 dyld3::MachOLoaded* mainExecutableMH, const dyld3::MachOLoaded* dyldMH, uintptr_t dyldSlide,
+ 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 dyld3::MachOLoaded* mainExecutableMH, const dyld3::MachOLoaded* dyldSimMH, uintptr_t dyldSlide,
+ const macho_header* mainExecutableMH, const macho_header* dyldMH, uintptr_t dyldSlide,
const dyld::SyscallHelpers* sc, uintptr_t* startGlue)
{
- // save table of syscall pointers
- gSyscallHelpers = sc;
-
- // dyld_sim uses chained rebases, so it always need to be fixed up
- rebaseDyld(dyldSimMH);
+ // 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);
@@ -173,8 +269,8 @@
syncProcessInfo();
// now that we are done bootstrapping dyld, call dyld's main
- uintptr_t appsSlide = mainExecutableMH->getSlide();
- return dyld::_main((macho_header*)mainExecutableMH, appsSlide, argc, argv, envp, apple, startGlue);
+ uintptr_t appsSlide = slideOfMainExecutable(mainExecutableMH);
+ return dyld::_main(mainExecutableMH, appsSlide, argc, argv, envp, apple, startGlue);
}
#endif