/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
*
- * Copyright (c) 2004-2007 Apple Inc. All rights reserved.
+ * Copyright (c) 2004-2010 Apple Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
#define __eip eip
#define __rip rip
-
+#define __STDC_LIMIT_MACROS
#include <string.h>
#include <fcntl.h>
+#include <errno.h>
#include <sys/types.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/mman.h>
-#include <mach/shared_memory_server.h>
#include <mach/mach.h>
#include <mach/thread_status.h>
#include <mach-o/loader.h>
-#include <mach-o/reloc.h>
#include <mach-o/nlist.h>
#include <sys/sysctl.h>
+#include <sys/syscall.h>
#include <libkern/OSAtomic.h>
#include <libkern/OSCacheControl.h>
-#if __ppc__ || __ppc64__
- #include <mach-o/ppc/reloc.h>
-#endif
-#if __x86_64__
- #include <mach-o/x86_64/reloc.h>
-#endif
+#include <stdint.h>
+#include <System/sys/codesign.h>
-#ifndef MH_PIE
- #define MH_PIE 0x200000
+#include "ImageLoaderMachO.h"
+#include "ImageLoaderMachOCompressed.h"
+#if SUPPORT_CLASSIC_MACHO
+#include "ImageLoaderMachOClassic.h"
#endif
+#include "mach-o/dyld_images.h"
-#ifndef S_DTRACE_DOF
- #define S_DTRACE_DOF 0xF
-#endif
+// <rdar://problem/8718137> use stack guard random value to add padding between dylibs
+extern "C" long __stack_chk_guard;
-#ifndef S_ATTR_SELF_MODIFYING_CODE
- #define S_ATTR_SELF_MODIFYING_CODE 0x04000000
+#ifndef LC_LOAD_UPWARD_DYLIB
+ #define LC_LOAD_UPWARD_DYLIB (0x23|LC_REQ_DYLD) /* load of dylib whose initializers run later */
#endif
-#include "ImageLoaderMachO.h"
-#include "mach-o/dyld_images.h"
-
-// optimize strcmp for ppc
-#if __ppc__
- #include <ppc_intrinsics.h>
-#else
- #define astrcmp(a,b) strcmp(a,b)
+#ifndef LC_VERSION_MIN_TVOS
+ #define LC_VERSION_MIN_TVOS 0x2F
#endif
-// in libc.a
-extern "C" void _spin_lock(uint32_t*);
-extern "C" void _spin_unlock(uint32_t*);
+#ifndef LC_VERSION_MIN_WATCHOS
+ #define LC_VERSION_MIN_WATCHOS 0x30
+#endif
// relocation_info.r_length field has value 3 for 64-bit executables and value 2 for 32-bit executables
#if __LP64__
- #define RELOC_SIZE 3
#define LC_SEGMENT_COMMAND LC_SEGMENT_64
#define LC_ROUTINES_COMMAND LC_ROUTINES_64
- struct macho_header : public mach_header_64 {};
+ #define LC_SEGMENT_COMMAND_WRONG LC_SEGMENT
struct macho_segment_command : public segment_command_64 {};
struct macho_section : public section_64 {};
- struct macho_nlist : public nlist_64 {};
struct macho_routines_command : public routines_command_64 {};
#else
- #define RELOC_SIZE 2
#define LC_SEGMENT_COMMAND LC_SEGMENT
#define LC_ROUTINES_COMMAND LC_ROUTINES
- struct macho_header : public mach_header {};
+ #define LC_SEGMENT_COMMAND_WRONG LC_SEGMENT_64
struct macho_segment_command : public segment_command {};
struct macho_section : public section {};
- struct macho_nlist : public nlist {};
struct macho_routines_command : public routines_command {};
#endif
-#if __x86_64__
- #define POINTER_RELOC X86_64_RELOC_UNSIGNED
-#else
- #define POINTER_RELOC GENERIC_RELOC_VANILLA
-#endif
-
-uint32_t ImageLoaderMachO::fgHintedBinaryTreeSearchs = 0;
-uint32_t ImageLoaderMachO::fgUnhintedBinaryTreeSearchs = 0;
-uint32_t ImageLoaderMachO::fgCountOfImagesWithWeakExports = 0;
-
-#if __i386__
-uint32_t ImageLoaderMachO::fgReadOnlyImportSpinLock = 0;
-#endif
-
-//#define LINKEDIT_USAGE_DEBUG 1
-
-#if LINKEDIT_USAGE_DEBUG
- #include <set>
- static std::set<uintptr_t> sLinkEditPageBuckets;
-
- namespace dyld {
- extern ImageLoader* findImageContainingAddress(const void* addr);
- };
+uint32_t ImageLoaderMachO::fgSymbolTableBinarySearchs = 0;
+uint32_t ImageLoaderMachO::fgSymbolTrieSearchs = 0;
- static void noteAccessedLinkEditAddress(const void* addr)
- {
- uintptr_t page = ((uintptr_t)addr) & (-4096);
- if ( sLinkEditPageBuckets.count(page) == 0 ) {
- ImageLoader* inImage = dyld::findImageContainingAddress(addr);
- dyld::log("dyld: accessing page 0x%016lX in __LINKEDIT of %s\n", page, inImage != NULL ? inImage->getPath() : "unknown" );
- }
- sLinkEditPageBuckets.insert(page);
- }
-#endif
-// only way to share initialization in C++
-void ImageLoaderMachO::init()
-{
- fMachOData = NULL;
- fLinkEditBase = NULL;
- fSymbolTable = NULL;
- fStrings = NULL;
- fDynamicInfo = NULL;
- fSlide = 0;
- fTwoLevelHints = NULL;
- fDylibID = NULL;
+ImageLoaderMachO::ImageLoaderMachO(const macho_header* mh, const char* path, unsigned int segCount,
+ uint32_t segOffsets[], unsigned int libCount)
+ : ImageLoader(path, libCount), fCoveredCodeLength(0), fMachOData((uint8_t*)mh), fLinkEditBase(NULL), fSlide(0),
+ fEHFrameSectionOffset(0), fUnwindInfoSectionOffset(0), fDylibIDOffset(0),
+fSegmentsCount(segCount), fIsSplitSeg(false), fInSharedCache(false),
#if TEXT_RELOC_SUPPORT
- fTextSegmentWithFixups = NULL;
+ fTextSegmentRebases(false),
+ fTextSegmentBinds(false),
#endif
#if __i386__
- fReadOnlyImportSegment = NULL;
-#endif
- fIsSplitSeg = false;
- fInSharedCache = false;
-#if __ppc64__
- f4GBWritable = false;
+ fReadOnlyImportSegment(false),
#endif
- fHasSubLibraries= false;
- fHasSubUmbrella = false;
- fInUmbrella = false;
- fHasDOFSections = false;
- fHasDashInit = false;
- fHasInitializers= false;
- fHasTerminators = false;
-#if IMAGE_NOTIFY_SUPPORT
- fHasImageNotifySection = false;
-#endif
-}
-
-// create image for main executable
-ImageLoaderMachO::ImageLoaderMachO(const struct mach_header* mh, uintptr_t slide, const char* path, const LinkContext& context)
- : ImageLoader(path)
+ fHasSubLibraries(false), fHasSubUmbrella(false), fInUmbrella(false), fHasDOFSections(false), fHasDashInit(false),
+ fHasInitializers(false), fHasTerminators(false), fRegisteredAsRequiresCoalescing(false)
{
- // clean slate
- this->init();
-
- // temporary use this buffer until TEXT is mapped in
- fMachOData = (const uint8_t*)mh;
-
- // create segments
- this->instantiateSegments((const uint8_t*)mh);
-
- // set slide for PIE programs
- this->setSlide(slide);
+ fIsSplitSeg = ((mh->flags & MH_SPLIT_SEGS) != 0);
- // get pointers to interesting things
- this->parseLoadCmds();
-
- // update segments to reference load commands in mapped in __TEXT segment
- this->adjustSegments();
-
-#if __i386__
- // kernel may have mapped in __IMPORT segment read-only, we need it read/write to do binding
- if ( fReadOnlyImportSegment != NULL )
- fReadOnlyImportSegment->tempWritable(context, this);
-#endif
-
- // for PIE record end of program, to know where to start loading dylibs
- if ( mh->flags & MH_PIE )
- Segment::fgNextPIEDylibAddress = (uintptr_t)this->getEnd();
-
- // notify state change
- this->setMapped(context);
-
- if ( context.verboseMapping ) {
- dyld::log("dyld: Main executable mapped %s\n", this->getPath());
- for (ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
- Segment* seg = *it;
- if ( (strcmp(seg->getName(), "__PAGEZERO") == 0) || (strcmp(seg->getName(), "__UNIXSTACK") == 0) )
- dyld::log("%18s at 0x%08lX->0x%08lX\n", seg->getName(), seg->getPreferredLoadAddress(), seg->getPreferredLoadAddress()+seg->getSize());
- else
- dyld::log("%18s at 0x%08lX->0x%08lX\n", seg->getName(), seg->getActualLoadAddress(this), seg->getActualLoadAddress(this)+seg->getSize());
+ // construct SegmentMachO object for each LC_SEGMENT cmd using "placement new" to put
+ // each SegmentMachO object in array at end of ImageLoaderMachO object
+ const uint32_t cmd_count = mh->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0, segIndex=0; i < cmd_count; ++i) {
+ if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
+ const struct macho_segment_command* segCmd = (struct macho_segment_command*)cmd;
+ // ignore zero-sized segments
+ if ( segCmd->vmsize != 0 ) {
+ // record offset of load command
+ segOffsets[segIndex++] = (uint32_t)((uint8_t*)segCmd - fMachOData);
+ }
}
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
+
}
-// create image by copying an in-memory mach-o file
-ImageLoaderMachO::ImageLoaderMachO(const char* moduleName, const struct mach_header* mh, uint64_t len, const LinkContext& context)
- : ImageLoader(moduleName)
+// determine if this mach-o file has classic or compressed LINKEDIT and number of segments it has
+void ImageLoaderMachO::sniffLoadCommands(const macho_header* mh, const char* path, bool inCache, bool* compressed,
+ unsigned int* segCount, unsigned int* libCount, const LinkContext& context,
+ const linkedit_data_command** codeSigCmd,
+ const encryption_info_command** encryptCmd)
{
- // clean slate
- this->init();
+ *compressed = false;
+ *segCount = 0;
+ *libCount = 0;
+ *codeSigCmd = NULL;
+ *encryptCmd = NULL;
- // temporary use this buffer until TEXT is mapped in
- fMachOData = (const uint8_t*)mh;
+ const uint32_t cmd_count = mh->ncmds;
+ const struct load_command* const startCmds = (struct load_command*)(((uint8_t*)mh) + sizeof(macho_header));
+ const struct load_command* const endCmds = (struct load_command*)(((uint8_t*)mh) + sizeof(macho_header) + mh->sizeofcmds);
+ const struct load_command* cmd = startCmds;
+ bool foundLoadCommandSegment = false;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ uint32_t cmdLength = cmd->cmdsize;
+ struct macho_segment_command* segCmd;
+ if ( cmdLength < 8 ) {
+ dyld::throwf("malformed mach-o image: load command #%d length (%u) too small in %s",
+ i, cmdLength, path);
+ }
+ const struct load_command* const nextCmd = (const struct load_command*)(((char*)cmd)+cmdLength);
+ if ( (nextCmd > endCmds) || (nextCmd < cmd) ) {
+ dyld::throwf("malformed mach-o image: load command #%d length (%u) would exceed sizeofcmds (%u) in %s",
+ i, cmdLength, mh->sizeofcmds, path);
+ }
+ switch (cmd->cmd) {
+ case LC_DYLD_INFO:
+ case LC_DYLD_INFO_ONLY:
+ *compressed = true;
+ break;
+ case LC_SEGMENT_COMMAND:
+ segCmd = (struct macho_segment_command*)cmd;
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+ // rdar://problem/19617624 allow unmapped segments on OSX (but not iOS)
+ if ( (segCmd->filesize > segCmd->vmsize) && (segCmd->vmsize != 0) )
+#else
+ if ( segCmd->filesize > segCmd->vmsize )
+#endif
+ dyld::throwf("malformed mach-o image: segment load command %s filesize is larger than vmsize", segCmd->segname);
+ // ignore zero-sized segments
+ if ( segCmd->vmsize != 0 )
+ *segCount += 1;
+ if ( context.codeSigningEnforced ) {
+ uintptr_t vmStart = segCmd->vmaddr;
+ uintptr_t vmSize = segCmd->vmsize;
+ uintptr_t vmEnd = vmStart + vmSize;
+ uintptr_t fileStart = segCmd->fileoff;
+ uintptr_t fileSize = segCmd->filesize;
+ if ( (intptr_t)(vmEnd) < 0)
+ dyld::throwf("malformed mach-o image: segment load command %s vmsize too large", segCmd->segname);
+ if ( vmStart > vmEnd )
+ dyld::throwf("malformed mach-o image: segment load command %s wraps around address space", segCmd->segname);
+ if ( vmSize != fileSize ) {
+ if ( (segCmd->initprot == 0) && (fileSize != 0) )
+ dyld::throwf("malformed mach-o image: unaccessable segment %s has filesize != 0", segCmd->segname);
+ else if ( vmSize < fileSize )
+ dyld::throwf("malformed mach-o image: segment %s has vmsize < filesize", segCmd->segname);
+ }
+ if ( inCache ) {
+ if ( (fileSize != 0) && (segCmd->initprot == (VM_PROT_READ | VM_PROT_EXECUTE)) ) {
+ if ( foundLoadCommandSegment )
+ throw "load commands in multiple segments";
+ foundLoadCommandSegment = true;
+ }
+ }
+ else if ( (fileStart < mh->sizeofcmds) && (fileSize != 0) ) {
+ // <rdar://problem/7942521> all load commands must be in an executable segment
+ if ( (fileStart != 0) || (fileSize < (mh->sizeofcmds+sizeof(macho_header))) )
+ dyld::throwf("malformed mach-o image: segment %s does not span all load commands", segCmd->segname);
+ if ( segCmd->initprot != (VM_PROT_READ | VM_PROT_EXECUTE) )
+ dyld::throwf("malformed mach-o image: load commands found in segment %s with wrong permissions", segCmd->segname);
+ if ( foundLoadCommandSegment )
+ throw "load commands in multiple segments";
+ foundLoadCommandSegment = true;
+ }
- // create segments
- this->instantiateSegments((const uint8_t*)mh);
-
- // map segments
- if ( mh->filetype == MH_EXECUTE ) {
- throw "can't load another MH_EXECUTE";
- }
- else {
- ImageLoader::mapSegments((const void*)mh, len, context);
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)segCmd + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[segCmd->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ if (!inCache && sect->offset != 0 && ((sect->offset + sect->size) > (segCmd->fileoff + segCmd->filesize)))
+ dyld::throwf("malformed mach-o image: section %s,%s of '%s' exceeds segment %s booundary", sect->segname, sect->sectname, path, segCmd->segname);
+ }
+ }
+ break;
+ case LC_SEGMENT_COMMAND_WRONG:
+ dyld::throwf("malformed mach-o image: wrong LC_SEGMENT[_64] for architecture");
+ break;
+ case LC_LOAD_DYLIB:
+ case LC_LOAD_WEAK_DYLIB:
+ case LC_REEXPORT_DYLIB:
+ case LC_LOAD_UPWARD_DYLIB:
+ *libCount += 1;
+ break;
+ case LC_CODE_SIGNATURE:
+ *codeSigCmd = (struct linkedit_data_command*)cmd; // only support one LC_CODE_SIGNATURE per image
+ break;
+ case LC_ENCRYPTION_INFO:
+ case LC_ENCRYPTION_INFO_64:
+ *encryptCmd = (struct encryption_info_command*)cmd; // only support one LC_ENCRYPTION_INFO[_64] per image
+ break;
+ }
+ cmd = nextCmd;
}
-
- // for compatibility, never unload dylibs loaded from memory
- this->setNeverUnload();
- // get pointers to interesting things
- this->parseLoadCmds();
+ if ( context.codeSigningEnforced && !foundLoadCommandSegment )
+ throw "load commands not in a segment";
- // update segments to reference load commands in mapped in __TEXT segment
- this->adjustSegments();
+ // <rdar://problem/13145644> verify every segment does not overlap another segment
+ if ( context.codeSigningEnforced ) {
+ uintptr_t lastFileStart = 0;
+ uintptr_t linkeditFileStart = 0;
+ const struct load_command* cmd1 = startCmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if ( cmd1->cmd == LC_SEGMENT_COMMAND ) {
+ struct macho_segment_command* segCmd1 = (struct macho_segment_command*)cmd1;
+ uintptr_t vmStart1 = segCmd1->vmaddr;
+ uintptr_t vmEnd1 = segCmd1->vmaddr + segCmd1->vmsize;
+ uintptr_t fileStart1 = segCmd1->fileoff;
+ uintptr_t fileEnd1 = segCmd1->fileoff + segCmd1->filesize;
+
+ if (fileStart1 > lastFileStart)
+ lastFileStart = fileStart1;
+
+ if ( strcmp(&segCmd1->segname[0], "__LINKEDIT") == 0 ) {
+ linkeditFileStart = fileStart1;
+ }
- // bundle loads need path copied
- if ( moduleName != NULL )
- this->setPath(moduleName);
-
- // notify state change
- this->setMapped(context);
-
-}
+ const struct load_command* cmd2 = startCmds;
+ for (uint32_t j = 0; j < cmd_count; ++j) {
+ if ( cmd2 == cmd1 )
+ continue;
+ if ( cmd2->cmd == LC_SEGMENT_COMMAND ) {
+ struct macho_segment_command* segCmd2 = (struct macho_segment_command*)cmd2;
+ uintptr_t vmStart2 = segCmd2->vmaddr;
+ uintptr_t vmEnd2 = segCmd2->vmaddr + segCmd2->vmsize;
+ uintptr_t fileStart2 = segCmd2->fileoff;
+ uintptr_t fileEnd2 = segCmd2->fileoff + segCmd2->filesize;
+ if ( ((vmStart2 <= vmStart1) && (vmEnd2 > vmStart1) && (vmEnd1 > vmStart1))
+ || ((vmStart2 >= vmStart1) && (vmStart2 < vmEnd1) && (vmEnd2 > vmStart2)) )
+ dyld::throwf("malformed mach-o image: segment %s vm overlaps segment %s", segCmd1->segname, segCmd2->segname);
+ if ( ((fileStart2 <= fileStart1) && (fileEnd2 > fileStart1) && (fileEnd1 > fileStart1))
+ || ((fileStart2 >= fileStart1) && (fileStart2 < fileEnd1) && (fileEnd2 > fileStart2)) )
+ dyld::throwf("malformed mach-o image: segment %s file content overlaps segment %s", segCmd1->segname, segCmd2->segname);
+ }
+ cmd2 = (const struct load_command*)(((char*)cmd2)+cmd2->cmdsize);
+ }
+ }
+ cmd1 = (const struct load_command*)(((char*)cmd1)+cmd1->cmdsize);
+ }
-// create image by using cached mach-o file
-ImageLoaderMachO::ImageLoaderMachO(const struct mach_header* mh, const char* path, const struct stat& info, const LinkContext& context)
- : ImageLoader(path, 0, info)
-{
- // clean slate
- this->init();
+ if (lastFileStart != linkeditFileStart)
+ dyld::throwf("malformed mach-o image: __LINKEDIT must be last segment");
+ }
- // already mapped to mh address
- fMachOData = (const uint8_t*)mh;
+ // fSegmentsArrayCount is only 8-bits
+ if ( *segCount > 255 )
+ dyld::throwf("malformed mach-o image: more than 255 segments in %s", path);
- // usually a split seg
- fIsSplitSeg = ((mh->flags & MH_SPLIT_SEGS) != 0);
-
- // remember this is from shared cache and cannot be unloaded
- fInSharedCache = true;
- this->setNeverUnload();
+ // fSegmentsArrayCount is only 8-bits
+ if ( *libCount > 4095 )
+ dyld::throwf("malformed mach-o image: more than 4095 dependent libraries in %s", path);
- // create segments
- this->instantiateSegments((const uint8_t*)mh);
-
- // segments already mapped in cache
- if ( context.verboseMapping ) {
- dyld::log("dyld: Using shared cached for %s\n", path);
- for (ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
- Segment* seg = *it;
- dyld::log("%18s at 0x%08lX->0x%08lX\n", seg->getName(), seg->getActualLoadAddress(this), seg->getActualLoadAddress(this)+seg->getSize());
- }
- }
+ if ( needsAddedLibSystemDepency(*libCount, mh) )
+ *libCount = 1;
+}
- // get pointers to interesting things
- this->parseLoadCmds();
- // note: path is mapped into cache so no need for ImageLoader to make a copy
- // notify state change
- this->setMapped(context);
+// create image for main executable
+ImageLoader* ImageLoaderMachO::instantiateMainExecutable(const macho_header* mh, uintptr_t slide, const char* path, const LinkContext& context)
+{
+ //dyld::log("ImageLoader=%ld, ImageLoaderMachO=%ld, ImageLoaderMachOClassic=%ld, ImageLoaderMachOCompressed=%ld\n",
+ // sizeof(ImageLoader), sizeof(ImageLoaderMachO), sizeof(ImageLoaderMachOClassic), sizeof(ImageLoaderMachOCompressed));
+ bool compressed;
+ unsigned int segCount;
+ unsigned int libCount;
+ const linkedit_data_command* codeSigCmd;
+ const encryption_info_command* encryptCmd;
+ sniffLoadCommands(mh, path, false, &compressed, &segCount, &libCount, context, &codeSigCmd, &encryptCmd);
+ // instantiate concrete class based on content of load commands
+ if ( compressed )
+ return ImageLoaderMachOCompressed::instantiateMainExecutable(mh, slide, path, segCount, libCount, context);
+ else
+#if SUPPORT_CLASSIC_MACHO
+ return ImageLoaderMachOClassic::instantiateMainExecutable(mh, slide, path, segCount, libCount, context);
+#else
+ throw "missing LC_DYLD_INFO load command";
+#endif
}
// create image by mapping in a mach-o file
-ImageLoaderMachO::ImageLoaderMachO(const char* path, int fd, const uint8_t firstPage[4096], uint64_t offsetInFat,
+ImageLoader* ImageLoaderMachO::instantiateFromFile(const char* path, int fd, const uint8_t firstPage[4096], uint64_t offsetInFat,
uint64_t lenInFat, const struct stat& info, const LinkContext& context)
- : ImageLoader(path, offsetInFat, info)
-{
- // clean slate
- this->init();
-
- // read load commands
+{
+ // get load commands
const unsigned int dataSize = sizeof(macho_header) + ((macho_header*)firstPage)->sizeofcmds;
uint8_t buffer[dataSize];
const uint8_t* fileData = firstPage;
memcpy(buffer, firstPage, 4096);
pread(fd, &buffer[4096], dataSize-4096, offsetInFat+4096);
}
-
- // temporary use this buffer until TEXT is mapped in
- fMachOData = fileData;
-
- // the meaning of many fields changes in split seg mach-o files
- fIsSplitSeg = ((((macho_header*)fileData)->flags & MH_SPLIT_SEGS) != 0) && (((macho_header*)fileData)->filetype == MH_DYLIB);
-
- // create segments
- this->instantiateSegments(fileData);
-
- // map segments, except for main executable which is already mapped in by kernel
- if ( ((macho_header*)fileData)->filetype != MH_EXECUTE )
- this->mapSegments(fd, offsetInFat, lenInFat, info.st_size, context);
-
- // get pointers to interesting things
- this->parseLoadCmds();
-
- // update segments to reference load commands in mapped in __TEXT segment
- this->adjustSegments();
-
- // notify state change
- this->setMapped(context);
-
- // if path happens to be same as in LC_DYLIB_ID load command use that, otherwise malloc a copy of the path
- const char* installName = getInstallPath();
- if ( (installName != NULL) && (strcmp(installName, path) == 0) && (path[0] == '/') )
- this->setPathUnowned(installName);
- if ( path[0] != '/' ) {
- // rdar://problem/5135363 turn relative paths into absolute paths so gdb, Symbolication can later find them
- char realPath[MAXPATHLEN];
- if ( realpath(path, realPath) != NULL )
- this->setPath(realPath);
- else
- this->setPath(path);
- }
- else
- this->setPath(path);
-
- // tell kernel about pages we are going to need soon
- if ( ! context.preFetchDisabled )
- this->preFetch(fd, offsetInFat, context);
+ bool compressed;
+ unsigned int segCount;
+ unsigned int libCount;
+ const linkedit_data_command* codeSigCmd;
+ const encryption_info_command* encryptCmd;
+ sniffLoadCommands((const macho_header*)fileData, path, false, &compressed, &segCount, &libCount, context, &codeSigCmd, &encryptCmd);
+ // instantiate concrete class based on content of load commands
+ if ( compressed )
+ return ImageLoaderMachOCompressed::instantiateFromFile(path, fd, fileData, dataSize, offsetInFat, lenInFat, info, segCount, libCount, codeSigCmd, encryptCmd, context);
+ else
+#if SUPPORT_CLASSIC_MACHO
+ return ImageLoaderMachOClassic::instantiateFromFile(path, fd, fileData, dataSize, offsetInFat, lenInFat, info, segCount, libCount, codeSigCmd, context);
+#else
+ throw "missing LC_DYLD_INFO load command";
+#endif
}
+// create image by using cached mach-o file
+ImageLoader* ImageLoaderMachO::instantiateFromCache(const macho_header* mh, const char* path, long slide, const struct stat& info, const LinkContext& context)
+{
+ // instantiate right concrete class
+ bool compressed;
+ unsigned int segCount;
+ unsigned int libCount;
+ const linkedit_data_command* codeSigCmd;
+ const encryption_info_command* encryptCmd;
+ sniffLoadCommands(mh, path, true, &compressed, &segCount, &libCount, context, &codeSigCmd, &encryptCmd);
+ // instantiate concrete class based on content of load commands
+ if ( compressed )
+ return ImageLoaderMachOCompressed::instantiateFromCache(mh, path, slide, info, segCount, libCount, context);
+ else
+#if SUPPORT_CLASSIC_MACHO
+ return ImageLoaderMachOClassic::instantiateFromCache(mh, path, slide, info, segCount, libCount, context);
+#else
+ throw "missing LC_DYLD_INFO load command";
+#endif
+}
+// create image by copying an in-memory mach-o file
+ImageLoader* ImageLoaderMachO::instantiateFromMemory(const char* moduleName, const macho_header* mh, uint64_t len, const LinkContext& context)
+{
+ bool compressed;
+ unsigned int segCount;
+ unsigned int libCount;
+ const linkedit_data_command* sigcmd;
+ const encryption_info_command* encryptCmd;
+ sniffLoadCommands(mh, moduleName, false, &compressed, &segCount, &libCount, context, &sigcmd, &encryptCmd);
+ // instantiate concrete class based on content of load commands
+ if ( compressed )
+ return ImageLoaderMachOCompressed::instantiateFromMemory(moduleName, mh, len, segCount, libCount, context);
+ else
+#if SUPPORT_CLASSIC_MACHO
+ return ImageLoaderMachOClassic::instantiateFromMemory(moduleName, mh, len, segCount, libCount, context);
+#else
+ throw "missing LC_DYLD_INFO load command";
+#endif
+}
-ImageLoaderMachO::~ImageLoaderMachO()
-{
- // keep count of images with weak exports
- if ( this->hasCoalescedExports() )
- --fgCountOfImagesWithWeakExports;
-
- // keep count of images used in shared cache
- if ( fInSharedCache )
- --fgImagesUsedFromSharedCache;
- // usually unmap image when done
- if ( ! this->leaveMapped() && (this->getState() >= dyld_image_state_mapped) ) {
- // first segment has load commands, so unmap last
- Segment* firstSeg = *(this->beginSegments());
- for(ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
- Segment* seg = *it;
- if ( seg != firstSeg )
- seg->unmap(this);
+int ImageLoaderMachO::crashIfInvalidCodeSignature()
+{
+ // Now that segments are mapped in, try reading from first executable segment.
+ // If code signing is enabled the kernel will validate the code signature
+ // when paging in, and kill the process if invalid.
+ for(unsigned int i=0; i < fSegmentsCount; ++i) {
+ if ( (segFileOffset(i) == 0) && (segFileSize(i) != 0) ) {
+ // return read value to ensure compiler does not optimize away load
+ int* p = (int*)segActualLoadAddress(i);
+ return *p;
}
- firstSeg->unmap(this);
}
- // free segment objects
- free(fSegmentsArray);
+ return 0;
}
-
-void ImageLoaderMachO::instantiateSegments(const uint8_t* fileData)
+void ImageLoaderMachO::parseLoadCmds(const LinkContext& context)
{
- const uint32_t cmd_count = ((macho_header*)fileData)->ncmds;
- const struct load_command* const cmds = (struct load_command*)&fileData[sizeof(macho_header)];
-
- // count LC_SEGMENT cmd and reserve that many segment slots
- uint32_t segCount = 0;
- const struct load_command* cmd = cmds;
- for (unsigned long i = 0; i < cmd_count; ++i) {
- if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
- // ignore zero-sized segments
- if ( ((struct macho_segment_command*)cmd)->vmsize != 0 )
- ++segCount;
+ // now that segments are mapped in, get real fMachOData, fLinkEditBase, and fSlide
+ for(unsigned int i=0; i < fSegmentsCount; ++i) {
+ // set up pointer to __LINKEDIT segment
+ if ( strcmp(segName(i),"__LINKEDIT") == 0 ) {
+ if ( context.codeSigningEnforced && (segFileOffset(i) > fCoveredCodeLength))
+ dyld::throwf("cannot load '%s' (segment outside of code signature)", this->getShortName());
+ fLinkEditBase = (uint8_t*)(segActualLoadAddress(i) - segFileOffset(i));
+ }
+#if TEXT_RELOC_SUPPORT
+ // __TEXT segment always starts at beginning of file and contains mach_header and load commands
+ if ( segExecutable(i) ) {
+ if ( segHasRebaseFixUps(i) && (fSlide != 0) )
+ fTextSegmentRebases = true;
+ if ( segHasBindFixUps(i) )
+ fTextSegmentBinds = true;
+ }
+#endif
+#if __i386__
+ if ( segIsReadOnlyImport(i) )
+ fReadOnlyImportSegment = true;
+#endif
+ // some segment always starts at beginning of file and contains mach_header and load commands
+ if ( (segFileOffset(i) == 0) && (segFileSize(i) != 0) ) {
+ fMachOData = (uint8_t*)(segActualLoadAddress(i));
}
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
- // fSegmentsArrayCount is only 8-bits
- if ( segCount > 255 )
- dyld::throwf("more than 255 segments in %s", this->getPath());
-
- // allocate array of segment objects in one call to malloc()
- //fSegmentsArray = static_cast<SegmentMachO*>(operator new[](segCount*sizeof(SegmentMachO)));
- fSegmentsArray = static_cast<SegmentMachO*>(malloc(segCount*sizeof(SegmentMachO)));
- fSegmentsArrayCount = segCount;
- // construct Segment object for each LC_SEGMENT cmd using "placment new"
- uint32_t segIndex = 0;
- cmd = cmds;
- for (unsigned long i = 0; i < cmd_count; ++i) {
- if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
- const struct macho_segment_command* segCmd = (struct macho_segment_command*)cmd;
- // ignore zero-sized segments
- if ( segCmd->vmsize != 0 )
- new (&fSegmentsArray[segIndex++]) SegmentMachO(segCmd);
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ // keep count of prebound images with weak exports
+ if ( this->participatesInCoalescing() ) {
+ ++fgImagesRequiringCoalescing;
+ fRegisteredAsRequiresCoalescing = true;
+ if ( this->hasCoalescedExports() )
+ ++fgImagesHasWeakDefinitions;
}
-}
+ // keep count of images used in shared cache
+ if ( fInSharedCache )
+ ++fgImagesUsedFromSharedCache;
-void ImageLoaderMachO::adjustSegments()
-{
- // tell each segment where is load command is finally mapped
+ // walk load commands (mapped in at start of __TEXT segment)
+ const dyld_info_command* dyldInfo = NULL;
+ const macho_nlist* symbolTable = NULL;
+ const char* symbolTableStrings = NULL;
+ const struct load_command* firstUnknownCmd = NULL;
+ const struct version_min_command* minOSVersionCmd = NULL;
+ const dysymtab_command* dynSymbolTable = NULL;
const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
- uint32_t segIndex = 0;
const struct load_command* cmd = cmds;
- for (unsigned long i = 0; i < cmd_count; ++i) {
- if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
- const struct macho_segment_command* segCmd = (struct macho_segment_command*)cmd;
- // ignore zero-sized segments
- if ( segCmd->vmsize != 0 ) {
- fSegmentsArray[segIndex].adjust(segCmd);
- ++segIndex;
- }
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SYMTAB:
+ {
+ const struct symtab_command* symtab = (struct symtab_command*)cmd;
+ symbolTableStrings = (const char*)&fLinkEditBase[symtab->stroff];
+ symbolTable = (macho_nlist*)(&fLinkEditBase[symtab->symoff]);
+ }
+ break;
+ case LC_DYSYMTAB:
+ dynSymbolTable = (struct dysymtab_command*)cmd;
+ break;
+ case LC_SUB_UMBRELLA:
+ fHasSubUmbrella = true;
+ break;
+ case LC_SUB_FRAMEWORK:
+ fInUmbrella = true;
+ break;
+ case LC_SUB_LIBRARY:
+ fHasSubLibraries = true;
+ break;
+ case LC_ROUTINES_COMMAND:
+ fHasDashInit = true;
+ break;
+ case LC_DYLD_INFO:
+ case LC_DYLD_INFO_ONLY:
+ dyldInfo = (struct dyld_info_command*)cmd;
+ break;
+ case LC_SEGMENT_COMMAND:
+ {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ const bool isTextSeg = (strcmp(seg->segname, "__TEXT") == 0);
+ 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_MOD_INIT_FUNC_POINTERS )
+ fHasInitializers = true;
+ else if ( type == S_MOD_TERM_FUNC_POINTERS )
+ fHasTerminators = true;
+ else if ( type == S_DTRACE_DOF )
+ fHasDOFSections = true;
+ else if ( isTextSeg && (strcmp(sect->sectname, "__eh_frame") == 0) )
+ fEHFrameSectionOffset = (uint32_t)((uint8_t*)sect - fMachOData);
+ else if ( isTextSeg && (strcmp(sect->sectname, "__unwind_info") == 0) )
+ fUnwindInfoSectionOffset = (uint32_t)((uint8_t*)sect - fMachOData);
+ }
+ }
+ break;
+ case LC_TWOLEVEL_HINTS:
+ // no longer supported
+ break;
+ case LC_ID_DYLIB:
+ {
+ fDylibIDOffset = (uint32_t)((uint8_t*)cmd - fMachOData);
+ }
+ break;
+ case LC_RPATH:
+ case LC_LOAD_WEAK_DYLIB:
+ case LC_REEXPORT_DYLIB:
+ case LC_LOAD_UPWARD_DYLIB:
+ case LC_MAIN:
+ // do nothing, just prevent LC_REQ_DYLD exception from occuring
+ break;
+ case LC_VERSION_MIN_MACOSX:
+ case LC_VERSION_MIN_IPHONEOS:
+ case LC_VERSION_MIN_TVOS:
+ case LC_VERSION_MIN_WATCHOS:
+ minOSVersionCmd = (version_min_command*)cmd;
+ break;
+ default:
+ if ( (cmd->cmd & LC_REQ_DYLD) != 0 ) {
+ if ( firstUnknownCmd == NULL )
+ firstUnknownCmd = cmd;
+ }
+ break;
}
cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
-}
-
-void ImageLoaderMachO::preFetch(int fd, uint64_t offsetInFat, const LinkContext& context)
-{
- // always prefetch a subrange of __LINKEDIT pages
- uintptr_t symbolTableOffset = (uintptr_t)fSymbolTable - (uintptr_t)fLinkEditBase;
- uintptr_t stringTableOffset = (uintptr_t)fStrings - (uintptr_t)fLinkEditBase;
- uintptr_t start;
- // if image did not load at preferred address
- if ( fSegmentsArray[0].getPreferredLoadAddress() != (uintptr_t)fMachOData ) {
- // local relocations will be processed, so start pre-fetch at local symbols
- start = offsetInFat + fDynamicInfo->locreloff;
- }
- else {
- // otherwise start pre-fetch at global symbols section of symbol table
- start = offsetInFat + symbolTableOffset + fDynamicInfo->iextdefsym * sizeof(macho_nlist);
+ if ( firstUnknownCmd != NULL ) {
+ if ( minOSVersionCmd != NULL ) {
+ dyld::throwf("cannot load '%s' because it was built for OS version %u.%u (load command 0x%08X is unknown)",
+ this->getShortName(),
+ minOSVersionCmd->version >> 16, ((minOSVersionCmd->version >> 8) & 0xff),
+ firstUnknownCmd->cmd);
+ }
+ else {
+ dyld::throwf("cannot load '%s' (load command 0x%08X is unknown)", this->getShortName(), firstUnknownCmd->cmd);
+ }
}
- // prefetch ends at end of last undefined string in string pool
- uintptr_t end = offsetInFat + stringTableOffset;
- if ( fDynamicInfo->nundefsym != 0 )
- end += fSymbolTable[fDynamicInfo->iundefsym+fDynamicInfo->nundefsym-1].n_un.n_strx;
- else if ( fDynamicInfo->nextdefsym != 0 )
- end += fSymbolTable[fDynamicInfo->iextdefsym+fDynamicInfo->nextdefsym-1].n_un.n_strx;
- radvisory advice;
- advice.ra_offset = start & (-4096); // page align
- advice.ra_count = (end-advice.ra_offset+4095) & (-4096);
- fgTotalBytesPreFetched += advice.ra_count;
- fcntl(fd, F_RDADVISE, &advice);
- if ( context.verboseMapping ) {
- dyld::log("%18s prefetching 0x%0llX -> 0x%0llX\n",
- "__LINKEDIT", advice.ra_offset+(uintptr_t)fLinkEditBase-offsetInFat, advice.ra_offset+advice.ra_count+(uintptr_t)fLinkEditBase-offsetInFat);
- }
- // prefetch __DATA/__OBJC pages during launch, but not for dynamically loaded code
- if ( context.linkingMainExecutable ) {
- for (ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
- Segment* seg = *it;
- if ( seg->writeable() && (seg->getFileSize() > 0) ) {
- // prefetch writable segment that have mmap'ed regions
- advice.ra_offset = offsetInFat + seg->getFileOffset();
- advice.ra_count = seg->getFileSize();
- // limit prefetch to 1MB (256 pages)
- if ( advice.ra_count > 1024*1024 )
- advice.ra_count = 1024*1024;
- fgTotalBytesPreFetched += advice.ra_count;
- fcntl(fd, F_RDADVISE, &advice);
- if ( context.verboseMapping ) {
- dyld::log("%18s prefetching 0x%0lX -> 0x%0lX\n",
- seg->getName(), seg->getActualLoadAddress(this), seg->getActualLoadAddress(this)+advice.ra_count-1);
- }
- }
- }
- }
+ if ( dyldInfo != NULL )
+ this->setDyldInfo(dyldInfo);
+ if ( symbolTable != NULL)
+ this->setSymbolTableInfo(symbolTable, symbolTableStrings, dynSymbolTable);
+
}
-bool ImageLoaderMachO::segmentsMustSlideTogether() const
+// don't do this work in destructor because we need object to be full subclass
+// for UnmapSegments() to work
+void ImageLoaderMachO::destroy()
{
- return true;
-}
+ // update count of images with weak exports
+ if ( fRegisteredAsRequiresCoalescing ) {
+ --fgImagesRequiringCoalescing;
+ if ( this->hasCoalescedExports() )
+ --fgImagesHasWeakDefinitions;
+ }
-bool ImageLoaderMachO::segmentsCanSlide() const
-{
- const macho_header* mh = (macho_header*)fMachOData;
- return ( (mh->filetype == MH_DYLIB) || (mh->filetype == MH_BUNDLE) );
+ // keep count of images used in shared cache
+ if ( fInSharedCache )
+ --fgImagesUsedFromSharedCache;
+
+ // unmap image when done
+ UnmapSegments();
}
-bool ImageLoaderMachO::isBundle() const
+
+unsigned int ImageLoaderMachO::segmentCount() const
{
- const macho_header* mh = (macho_header*)fMachOData;
- return ( mh->filetype == MH_BUNDLE );
+ return fSegmentsCount;
}
-bool ImageLoaderMachO::isDylib() const
+
+const macho_segment_command* ImageLoaderMachO::segLoadCommand(unsigned int segIndex) const
{
- const macho_header* mh = (macho_header*)fMachOData;
- return ( mh->filetype == MH_DYLIB );
+ uint32_t* lcOffsets = this->segmentCommandOffsets();
+ uint32_t lcOffset = lcOffsets[segIndex];
+ return (macho_segment_command*)(&fMachOData[lcOffset]);
}
-bool ImageLoaderMachO::forceFlat() const
+const char* ImageLoaderMachO::segName(unsigned int segIndex) const
{
- const macho_header* mh = (macho_header*)fMachOData;
- return ( (mh->flags & MH_FORCE_FLAT) != 0 );
+ return segLoadCommand(segIndex)->segname;
}
-bool ImageLoaderMachO::usesTwoLevelNameSpace() const
+
+uintptr_t ImageLoaderMachO::segSize(unsigned int segIndex) const
{
- const macho_header* mh = (macho_header*)fMachOData;
- return ( (mh->flags & MH_TWOLEVEL) != 0 );
+ return segLoadCommand(segIndex)->vmsize;
}
-bool ImageLoaderMachO::isPrebindable() const
+
+uintptr_t ImageLoaderMachO::segFileSize(unsigned int segIndex) const
{
- const macho_header* mh = (macho_header*)fMachOData;
- return ( (mh->flags & MH_PREBOUND) != 0 );
+ return segLoadCommand(segIndex)->filesize;
}
-bool ImageLoaderMachO::hasCoalescedExports() const
+
+bool ImageLoaderMachO::segHasTrailingZeroFill(unsigned int segIndex)
{
- const macho_header* mh = (macho_header*)fMachOData;
- return ( (mh->flags & MH_WEAK_DEFINES) != 0 );
+ return ( segWriteable(segIndex) && (segSize(segIndex) > segFileSize(segIndex)) );
}
-bool ImageLoaderMachO::needsCoalescing() const
+
+uintptr_t ImageLoaderMachO::segFileOffset(unsigned int segIndex) const
{
- const macho_header* mh = (macho_header*)fMachOData;
- return ( (mh->flags & MH_BINDS_TO_WEAK) != 0 );
+ return segLoadCommand(segIndex)->fileoff;
}
+bool ImageLoaderMachO::segReadable(unsigned int segIndex) const
+{
+ return ( (segLoadCommand(segIndex)->initprot & VM_PROT_READ) != 0);
+}
+bool ImageLoaderMachO::segWriteable(unsigned int segIndex) const
+{
+ return ( (segLoadCommand(segIndex)->initprot & VM_PROT_WRITE) != 0);
+}
-// hack until kernel headers and glue are in system
-struct _shared_region_mapping_np {
- mach_vm_address_t address;
- mach_vm_size_t size;
- mach_vm_offset_t file_offset;
- vm_prot_t max_prot; /* read/write/execute/COW/ZF */
- vm_prot_t init_prot; /* read/write/execute/COW/ZF */
-};
-struct _shared_region_range_np {
- mach_vm_address_t address;
- mach_vm_size_t size;
-};
-
-#if SPLIT_SEG_SHARED_REGION_SUPPORT
-// Called by dyld.
-// Requests the kernel to map a number of regions from the fd into the
-// shared sections address range (0x90000000-0xAFFFFFFF).
-// If shared_region_make_private_np() has not been called by this process,
-// the file mapped in is seen in the address space of all processes that
-// participate in using the shared region.
-// If shared_region_make_private_np() _has_ been called by this process,
-// the file mapped in is only seen by this process.
-// If the slide parameter is not NULL and then regions cannot be mapped
-// as requested, the kernel will try to map the file in at a different
-// address in the shared region and return the distance slid.
-// If the mapping requesting cannot be fulfilled, returns non-zero.
-static int
-_shared_region_map_file_np(
- int fd, // file descriptor to map into shared region
- unsigned int regionCount, // number of entres in array of regions
- const _shared_region_mapping_np regions[], // the array of regions to map
- uint64_t* slide) // the amount all regions were slid, NULL means don't attempt to slide
-{
- //dyld::log("%s(%i, %u, %8p, %8p)\n", __func__, fd, regionCount, regions, slide);
- //for ( unsigned int i=0; i < regionCount; ++i) {
- // dyld::log("\taddress=0x%08llX, size=0x%08llX\n", regions[i].address, regions[i].size);
- //}
- int r = syscall(299, fd, regionCount, regions, slide);
-// if(0 != r)
-// dyld::log("%s(%i, %u, %8p, %8p) errno=%i (%s)\n", __func__, fd, regionCount, regions, slide, errno, strerror(errno));
- return r;
-}
-// Called by dyld if shared_region_map_file() fails.
-// Requests the kernel to take this process out of using the shared region.
-// The specified ranges are created as private copies from the shared region for this process.
-static int
-_shared_region_make_private_np(
- unsigned int rangeCount, // number of entres in array of msrp_range
- const _shared_region_range_np ranges[]) // the array of shared regions to make private
-{
- //dyld::log("%s(%u, %8p)\n", __func__, rangeCount, ranges);
- int r = syscall(300, rangeCount, ranges);
-// if(0 != r)
-// dyld::log("%s(%u, %8p) errno=%i (%s)\n", __func__, rangeCount, ranges, errno, strerror(errno));
- return r;
-}
-#define KERN_SHREG_PRIVATIZABLE 54
-
-
-static int
-_shared_region_map_file_with_mmap(
- int fd, // file descriptor to map into shared region
- unsigned int regionCount, // number of entres in array of regions
- const _shared_region_mapping_np regions[]) // the array of regions to map
-{
- // map in each region
- for(unsigned int i=0; i < regionCount; ++i) {
- void* mmapAddress = (void*)(uintptr_t)(regions[i].address);
- size_t size = regions[i].size;
- if ( (regions[i].init_prot & VM_PROT_ZF) != 0 ) {
- // do nothing already vm_allocate() which zero fills
- }
- else {
- int protection = 0;
- if ( regions[i].init_prot & VM_PROT_EXECUTE )
- protection |= PROT_EXEC;
- if ( regions[i].init_prot & VM_PROT_READ )
- protection |= PROT_READ;
- if ( regions[i].init_prot & VM_PROT_WRITE )
- protection |= PROT_WRITE;
- off_t offset = regions[i].file_offset;
- //dyld::log("mmap(%p, 0x%08lX, block=0x%08X, %s\n", mmapAddress, size, biggestDiff, fPath);
- mmapAddress = mmap(mmapAddress, size, protection, MAP_FIXED | MAP_PRIVATE, fd, offset);
- if ( mmapAddress == ((void*)(-1)) )
- throw "mmap error";
- }
- }
-
- return 0;
+bool ImageLoaderMachO::segExecutable(unsigned int segIndex) const
+{
+ return ( (segLoadCommand(segIndex)->initprot & VM_PROT_EXECUTE) != 0);
}
-static
-bool
-hasSharedRegionMapFile(void)
+bool ImageLoaderMachO::segUnaccessible(unsigned int segIndex) const
{
- int mib[CTL_MAXNAME];
- int value = 0;
- size_t size;
+ return (segLoadCommand(segIndex)->initprot == 0);
+}
- mib[0] = CTL_KERN;
- mib[1] = KERN_SHREG_PRIVATIZABLE;
- size = sizeof (int);
- if (sysctl(mib, 2, &value, &size, NULL, 0) != 0) {
- value = 0;
- }
+bool ImageLoaderMachO::segHasPreferredLoadAddress(unsigned int segIndex) const
+{
+ return (segLoadCommand(segIndex)->vmaddr != 0);
+}
+
+uintptr_t ImageLoaderMachO::segPreferredLoadAddress(unsigned int segIndex) const
+{
+ return segLoadCommand(segIndex)->vmaddr;
+}
- return 0 != value;
+uintptr_t ImageLoaderMachO::segActualLoadAddress(unsigned int segIndex) const
+{
+ return segLoadCommand(segIndex)->vmaddr + fSlide;
}
-#endif // SPLIT_SEG_SHARED_REGION_SUPPORT
+uintptr_t ImageLoaderMachO::segActualEndAddress(unsigned int segIndex) const
+{
+ return segActualLoadAddress(segIndex) + segSize(segIndex);
+}
-#if SPLIT_SEG_DYLIB_SUPPORT
-unsigned int
-ImageLoaderMachO::getExtraZeroFillEntriesCount()
+bool ImageLoaderMachO::segHasRebaseFixUps(unsigned int segIndex) const
{
- // calculate mapping entries
- unsigned int extraZeroFillEntries = 0;
- for(ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
- Segment* seg = *it;
- if ( seg->hasTrailingZeroFill() )
- ++extraZeroFillEntries;
+#if TEXT_RELOC_SUPPORT
+ // scan sections for fix-up bit
+ const macho_segment_command* segCmd = segLoadCommand(segIndex);
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)segCmd + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[segCmd->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ if ( (sect->flags & S_ATTR_LOC_RELOC) != 0 )
+ return true;
}
-
- return extraZeroFillEntries;
-}
-
-void
-ImageLoaderMachO::initMappingTable(uint64_t offsetInFat,
- _shared_region_mapping_np *mappingTable)
-{
- unsigned int segmentCount = fSegmentsArrayCount;
- for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
- Segment* seg = &fSegmentsArray[segIndex];
- _shared_region_mapping_np* entry = &mappingTable[entryIndex];
- entry->address = seg->getActualLoadAddress(this);
- entry->size = seg->getFileSize();
- entry->file_offset = seg->getFileOffset() + offsetInFat;
- entry->init_prot = VM_PROT_NONE;
- if ( !seg->unaccessible() ) {
- if ( seg->executable() )
- entry->init_prot |= VM_PROT_EXECUTE;
- if ( seg->readable() )
- entry->init_prot |= VM_PROT_READ;
- if ( seg->writeable() )
- entry->init_prot |= VM_PROT_WRITE | VM_PROT_COW;
- }
- entry->max_prot = entry->init_prot;
- if ( seg->hasTrailingZeroFill() ) {
- _shared_region_mapping_np* zfentry = &mappingTable[++entryIndex];
- zfentry->address = entry->address + seg->getFileSize();
- zfentry->size = seg->getSize() - seg->getFileSize();
- zfentry->file_offset = 0;
- zfentry->init_prot = entry->init_prot | VM_PROT_COW | VM_PROT_ZF;
- zfentry->max_prot = zfentry->init_prot;
- }
+#endif
+ return false;
+}
+
+bool ImageLoaderMachO::segHasBindFixUps(unsigned int segIndex) const
+{
+#if TEXT_RELOC_SUPPORT
+ // scan sections for fix-up bit
+ const macho_segment_command* segCmd = segLoadCommand(segIndex);
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)segCmd + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[segCmd->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ if ( (sect->flags & S_ATTR_EXT_RELOC) != 0 )
+ return true;
}
+#endif
+ return false;
}
-int
-ImageLoaderMachO::sharedRegionMapFilePrivateOutside(int fd,
- uint64_t offsetInFat,
- uint64_t lenInFat,
- uint64_t fileLen,
- const LinkContext& context)
+#if __i386__
+bool ImageLoaderMachO::segIsReadOnlyImport(unsigned int segIndex) const
{
- static uintptr_t sNextAltLoadAddress
- #if __ppc_
- = 0xC0000000;
- #else
- = 0;
- #endif
+ const macho_segment_command* segCmd = segLoadCommand(segIndex);
+ return ( (segCmd->initprot & VM_PROT_EXECUTE)
+ && ((segCmd->initprot & VM_PROT_WRITE) == 0)
+ && (strcmp(segCmd->segname, "__IMPORT") == 0) );
+}
+#endif
- const unsigned int segmentCount = fSegmentsArrayCount;
- const unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
- const unsigned int regionCount = segmentCount+extraZeroFillEntries;
- _shared_region_mapping_np regions[regionCount];
- initMappingTable(offsetInFat, regions);
- int r = -1;
- // find space somewhere to allocate split seg
- bool foundRoom = false;
- vm_size_t biggestDiff = 0;
- while ( ! foundRoom ) {
- foundRoom = true;
- for(unsigned int i=0; i < regionCount; ++i) {
- vm_address_t addr = sNextAltLoadAddress + regions[i].address - regions[0].address;
- vm_size_t size = regions[i].size ;
- r = vm_allocate(mach_task_self(), &addr, size, false /*only this range*/);
- if ( 0 != r ) {
- // no room here, deallocate what has succeeded so far
- for(unsigned int j=0; j < i; ++j) {
- vm_address_t addr = sNextAltLoadAddress + regions[j].address - regions[0].address;
- vm_size_t size = regions[j].size ;
- (void)vm_deallocate(mach_task_self(), addr, size);
- }
- sNextAltLoadAddress += 0x00100000; // skip ahead 1MB and try again
- if ( (sNextAltLoadAddress & 0xF0000000) == 0x90000000 )
- sNextAltLoadAddress = 0xB0000000;
- if ( (sNextAltLoadAddress & 0xF0000000) == 0xF0000000 )
- throw "can't map split seg anywhere";
- foundRoom = false;
- break;
- }
- vm_size_t high = (regions[i].address + size - regions[0].address) & 0x0FFFFFFF;
- if ( high > biggestDiff )
- biggestDiff = high;
- }
- }
-
- // map in each region
- uintptr_t slide = sNextAltLoadAddress - regions[0].address;
- this->setSlide(slide);
- for(unsigned int i=0; i < regionCount; ++i) {
- if ( ((regions[i].init_prot & VM_PROT_ZF) != 0) || (regions[i].size == 0) ) {
- // nothing to mmap for zero-fills areas, they are just vm_allocated
+
+void ImageLoaderMachO::UnmapSegments()
+{
+ // usually unmap image when done
+ if ( ! this->leaveMapped() && (this->getState() >= dyld_image_state_mapped) ) {
+ // unmap TEXT segment last because it contains load command being inspected
+ unsigned int textSegmentIndex = 0;
+ for(unsigned int i=0; i < fSegmentsCount; ++i) {
+ //dyld::log("unmap %s at 0x%08lX\n", seg->getName(), seg->getActualLoadAddress(this));
+ if ( strcmp(segName(i), "__TEXT") == 0 ) {
+ textSegmentIndex = i;
}
else {
- void* mmapAddress = (void*)(uintptr_t)(regions[i].address + slide);
- size_t size = regions[i].size;
- int protection = 0;
- if ( regions[i].init_prot & VM_PROT_EXECUTE )
- protection |= PROT_EXEC;
- if ( regions[i].init_prot & VM_PROT_READ )
- protection |= PROT_READ;
- if ( regions[i].init_prot & VM_PROT_WRITE )
- protection |= PROT_WRITE;
- off_t offset = regions[i].file_offset;
- //dyld::log("mmap(%p, 0x%08lX, block=0x%08X, %s\n", mmapAddress, size, biggestDiff, fPath);
- mmapAddress = mmap(mmapAddress, size, protection, MAP_FIXED | MAP_PRIVATE, fd, offset);
- if ( mmapAddress == ((void*)(-1)) )
- throw "mmap error";
- }
- }
- // set so next maps right after this one
- sNextAltLoadAddress += biggestDiff;
- sNextAltLoadAddress = (sNextAltLoadAddress + 4095) & (-4096);
-
- // logging
- if ( context.verboseMapping ) {
- dyld::log("dyld: Mapping split-seg outside shared region, slid by 0x%08lX %s\n", this->fSlide, this->getPath());
- for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
- Segment* seg = &fSegmentsArray[segIndex];
- const _shared_region_mapping_np* entry = ®ions[entryIndex];
- if ( (entry->init_prot & VM_PROT_ZF) == 0 )
- dyld::log("%18s at 0x%08lX->0x%08lX\n",
- seg->getName(), seg->getActualLoadAddress(this), seg->getActualLoadAddress(this)+seg->getFileSize()-1);
- if ( entryIndex < (regionCount-1) ) {
- const _shared_region_mapping_np* nextEntry = ®ions[entryIndex+1];
- if ( (nextEntry->init_prot & VM_PROT_ZF) != 0 ) {
- uint64_t segOffset = nextEntry->address - entry->address;
- dyld::log("%18s at 0x%08lX->0x%08lX (zerofill)\n",
- seg->getName(), (uintptr_t)(seg->getActualLoadAddress(this) + segOffset), (uintptr_t)(seg->getActualLoadAddress(this) + segOffset + nextEntry->size - 1));
- ++entryIndex;
- }
- }
+ // update stats
+ --ImageLoader::fgTotalSegmentsMapped;
+ ImageLoader::fgTotalBytesMapped -= segSize(i);
+ munmap((void*)segActualLoadAddress(i), segSize(i));
}
}
-
- return r;
+ // now unmap TEXT
+ --ImageLoader::fgTotalSegmentsMapped;
+ ImageLoader::fgTotalBytesMapped -= segSize(textSegmentIndex);
+ munmap((void*)segActualLoadAddress(textSegmentIndex), segSize(textSegmentIndex));
+ }
}
-void ImageLoaderMachO::mapSegments(int fd, uint64_t offsetInFat, uint64_t lenInFat, uint64_t fileLen, const LinkContext& context)
+// prefetch __DATA/__OBJC pages during launch, but not for dynamically loaded code
+void ImageLoaderMachO::preFetchDATA(int fd, uint64_t offsetInFat, const LinkContext& context)
{
- // non-split segment libraries handled by super class
- if ( !fIsSplitSeg )
- return ImageLoader::mapSegments(fd, offsetInFat, lenInFat, fileLen, context);
-
-#if SPLIT_SEG_SHARED_REGION_SUPPORT
- enum SharedRegionState
- {
- kSharedRegionStartState = 0,
- kSharedRegionMapFileState,
- kSharedRegionMapFilePrivateState,
- kSharedRegionMapFilePrivateMMapState,
- kSharedRegionMapFilePrivateOutsideState,
- };
- static SharedRegionState sSharedRegionState = kSharedRegionStartState;
-
- if ( kSharedRegionStartState == sSharedRegionState ) {
- if ( hasSharedRegionMapFile() ) {
- if ( context.sharedRegionMode == kUsePrivateSharedRegion ) {
- sharedRegionMakePrivate(context);
- sSharedRegionState = kSharedRegionMapFilePrivateState;
- }
- else if ( context.sharedRegionMode == kDontUseSharedRegion ) {
- sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
- }
- else if ( context.sharedRegionMode == kSharedRegionIsSharedCache ) {
- sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
- }
- else {
- sSharedRegionState = kSharedRegionMapFileState;
+ if ( context.linkingMainExecutable ) {
+ for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+ if ( segWriteable(i) && (segFileSize(i) > 0) ) {
+ // prefetch writable segment that have mmap'ed regions
+ radvisory advice;
+ advice.ra_offset = offsetInFat + segFileOffset(i);
+ advice.ra_count = (int)segFileSize(i);
+ // limit prefetch to 1MB (256 pages)
+ if ( advice.ra_count > 1024*1024 )
+ advice.ra_count = 1024*1024;
+ // don't prefetch single pages, let them fault in
+ fgTotalBytesPreFetched += advice.ra_count;
+ fcntl(fd, F_RDADVISE, &advice);
+ if ( context.verboseMapping ) {
+ dyld::log("%18s prefetching 0x%0lX -> 0x%0lX\n",
+ segName(i), segActualLoadAddress(i), segActualLoadAddress(i)+advice.ra_count-1);
+ }
}
}
- else {
- sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
- }
- }
-
- if ( kSharedRegionMapFileState == sSharedRegionState ) {
- if ( 0 != sharedRegionMapFile(fd, offsetInFat, lenInFat, fileLen, context) ) {
- sharedRegionMakePrivate(context);
- sSharedRegionState = kSharedRegionMapFilePrivateState;
- }
- }
-
- if ( (kSharedRegionMapFilePrivateState == sSharedRegionState) || (kSharedRegionMapFilePrivateMMapState == sSharedRegionState) ) {
- if ( 0 != sharedRegionMapFilePrivate(fd, offsetInFat, lenInFat, fileLen, context, (kSharedRegionMapFilePrivateMMapState == sSharedRegionState)) ) {
- sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
- }
- }
-
- if ( kSharedRegionMapFilePrivateOutsideState == sSharedRegionState ) {
- if ( 0 != sharedRegionMapFilePrivateOutside(fd, offsetInFat, lenInFat, fileLen, context) ) {
- throw "mapping error";
- }
- }
-#else
- // support old split-seg dylibs by mapping them where ever we find space
- if ( sharedRegionMapFilePrivateOutside(fd, offsetInFat, lenInFat, fileLen, context) != 0 ) {
- throw "mapping error";
}
-#endif
}
-#endif // SPLIT_SEG_DYLIB_SUPPORT
-#if SPLIT_SEG_SHARED_REGION_SUPPORT
-int ImageLoaderMachO::sharedRegionMakePrivate(const LinkContext& context)
+bool ImageLoaderMachO::segmentsMustSlideTogether() const
{
- if ( context.verboseMapping )
- dyld::log("dyld: making shared regions private\n");
-
- // shared mapping failed, so make private copy of shared region and try mapping private
- MappedRegion allRegions[context.imageCount()*8]; // assume average of less that eight segments per image
- MappedRegion* end = context.getAllMappedRegions(allRegions);
- _shared_region_range_np splitSegRegions[end-allRegions];
- _shared_region_range_np* sp = splitSegRegions;
- for (MappedRegion* p=allRegions; p < end; ++p) {
- uint8_t highByte = p->address >> 28;
- if ( (highByte == 9) || (highByte == 0xA) ) {
- _shared_region_range_np splitRegion;
- splitRegion.address = p->address;
- splitRegion.size = p->size;
- *sp++ = splitRegion;
- }
- }
- int result = _shared_region_make_private_np(sp-splitSegRegions, splitSegRegions);
- // notify gdb or other lurkers that this process is no longer using the shared region
- dyld_all_image_infos.processDetachedFromSharedRegion = true;
- return result;
+ return true;
}
-int
-ImageLoaderMachO::sharedRegionMapFile(int fd,
- uint64_t offsetInFat,
- uint64_t lenInFat,
- uint64_t fileLen,
- const LinkContext& context)
-{
- // build table of segments to map
- const unsigned int segmentCount = fSegmentsArrayCount;
- const unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
- const unsigned int mappingTableCount = segmentCount+extraZeroFillEntries;
- _shared_region_mapping_np mappingTable[mappingTableCount];
- initMappingTable(offsetInFat, mappingTable);
-// uint64_t slide;
- uint64_t *slidep = NULL;
-
- // try to map it in shared
- int r = _shared_region_map_file_np(fd, mappingTableCount, mappingTable, slidep);
- if ( 0 == r ) {
- if(NULL != slidep && 0 != *slidep) {
- // update with actual load addresses
- }
- this->setNeverUnload();
- if ( context.verboseMapping ) {
- dyld::log("dyld: Mapping split-seg shared %s\n", this->getPath());
- for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
- Segment* seg = &fSegmentsArray[segIndex];
- const _shared_region_mapping_np* entry = &mappingTable[entryIndex];
- if ( (entry->init_prot & VM_PROT_ZF) == 0 )
- dyld::log("%18s at 0x%08lX->0x%08lX\n",
- seg->getName(), seg->getActualLoadAddress(this), seg->getActualLoadAddress(this)+seg->getFileSize()-1);
- if ( entryIndex < (mappingTableCount-1) ) {
- const _shared_region_mapping_np* nextEntry = &mappingTable[entryIndex+1];
- if ( (nextEntry->init_prot & VM_PROT_ZF) != 0 ) {
- uint64_t segOffset = nextEntry->address - entry->address;
- dyld::log("%18s at 0x%08lX->0x%08lX\n",
- seg->getName(), (uintptr_t)(seg->getActualLoadAddress(this) + segOffset), (uintptr_t)(seg->getActualLoadAddress(this) + segOffset + nextEntry->size - 1));
- ++entryIndex;
- }
- }
- }
- }
- }
- return r;
+bool ImageLoaderMachO::segmentsCanSlide() const
+{
+ return (this->isDylib() || this->isBundle() || this->isPositionIndependentExecutable());
}
+bool ImageLoaderMachO::isBundle() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( mh->filetype == MH_BUNDLE );
+}
-int
-ImageLoaderMachO::sharedRegionMapFilePrivate(int fd,
- uint64_t offsetInFat,
- uint64_t lenInFat,
- uint64_t fileLen,
- const LinkContext& context,
- bool usemmap)
+bool ImageLoaderMachO::isDylib() const
{
- const unsigned int segmentCount = fSegmentsArrayCount;
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( mh->filetype == MH_DYLIB );
+}
- // build table of segments to map
- const unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
- const unsigned int mappingTableCount = segmentCount+extraZeroFillEntries;
- _shared_region_mapping_np mappingTable[mappingTableCount];
- initMappingTable(offsetInFat, mappingTable);
- uint64_t slide = 0;
+bool ImageLoaderMachO::isExecutable() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( mh->filetype == MH_EXECUTE );
+}
- // try map it in privately (don't allow sliding if we pre-calculated the load address to pack dylibs)
- int r;
- if ( usemmap )
- r = _shared_region_map_file_with_mmap(fd, mappingTableCount, mappingTable);
- else
- r = _shared_region_map_file_np(fd, mappingTableCount, mappingTable, &slide);
- if ( 0 == r ) {
- if ( 0 != slide ) {
- slide = (slide) & (-4096); // round down to page boundary
- this->setSlide(slide);
- }
- this->setNeverUnload();
- if ( context.verboseMapping ) {
- if ( slide == 0 )
- dyld::log("dyld: Mapping split-seg un-shared %s\n", this->getPath());
- else
- dyld::log("dyld: Mapping split-seg un-shared slid by 0x%08llX %s\n", slide, this->getPath());
- for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
- Segment* seg = &fSegmentsArray[segIndex];
- const _shared_region_mapping_np* entry = &mappingTable[entryIndex];
- if ( (entry->init_prot & VM_PROT_ZF) == 0 )
- dyld::log("%18s at 0x%08lX->0x%08lX\n",
- seg->getName(), seg->getActualLoadAddress(this), seg->getActualLoadAddress(this)+seg->getFileSize()-1);
- if ( entryIndex < (mappingTableCount-1) ) {
- const _shared_region_mapping_np* nextEntry = &mappingTable[entryIndex+1];
- if ( (nextEntry->init_prot & VM_PROT_ZF) != 0 ) {
- uint64_t segOffset = nextEntry->address - entry->address;
- dyld::log("%18s at 0x%08lX->0x%08lX (zerofill)\n",
- seg->getName(), (uintptr_t)(seg->getActualLoadAddress(this) + segOffset), (uintptr_t)(seg->getActualLoadAddress(this) + segOffset + nextEntry->size - 1));
- ++entryIndex;
- }
- }
- }
- }
- }
- if ( r != 0 )
- dyld::throwf("can't rebase split-seg dylib %s because shared_region_map_file_np() returned %d", this->getPath(), r);
-
- return r;
-}
-
-void
-ImageLoaderMachO::initMappingTable(uint64_t offsetInFat,
- sf_mapping *mappingTable,
- uintptr_t baseAddress)
-{
- unsigned int segmentCount = fSegmentsArrayCount;
- for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
- Segment* seg = &fSegmentsArray[segIndex];
- sf_mapping* entry = &mappingTable[entryIndex];
- entry->mapping_offset = seg->getPreferredLoadAddress() - baseAddress;
- entry->size = seg->getFileSize();
- entry->file_offset = seg->getFileOffset() + offsetInFat;
- entry->protection = VM_PROT_NONE;
- if ( !seg->unaccessible() ) {
- if ( seg->executable() )
- entry->protection |= VM_PROT_EXECUTE;
- if ( seg->readable() )
- entry->protection |= VM_PROT_READ;
- if ( seg->writeable() )
- entry->protection |= VM_PROT_WRITE | VM_PROT_COW;
- }
-
- entry->cksum = 0;
- if ( seg->hasTrailingZeroFill() ) {
- sf_mapping* zfentry = &mappingTable[++entryIndex];
- zfentry->mapping_offset = entry->mapping_offset + seg->getFileSize();
- zfentry->size = seg->getSize() - seg->getFileSize();
- zfentry->file_offset = 0;
- zfentry->protection = entry->protection | VM_PROT_COW | VM_PROT_ZF;
- zfentry->cksum = 0;
- }
- }
+bool ImageLoaderMachO::isPositionIndependentExecutable() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->filetype == MH_EXECUTE) && ((mh->flags & MH_PIE) != 0) );
+}
+
+
+bool ImageLoaderMachO::forceFlat() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->flags & MH_FORCE_FLAT) != 0 );
+}
+
+bool ImageLoaderMachO::usesTwoLevelNameSpace() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->flags & MH_TWOLEVEL) != 0 );
+}
+
+bool ImageLoaderMachO::isPrebindable() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->flags & MH_PREBOUND) != 0 );
+}
+
+bool ImageLoaderMachO::hasCoalescedExports() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->flags & MH_WEAK_DEFINES) != 0 );
+}
+
+bool ImageLoaderMachO::hasReferencesToWeakSymbols() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->flags & MH_BINDS_TO_WEAK) != 0 );
}
-#endif // SPLIT_SEG_SHARED_REGION_SUPPORT
+bool ImageLoaderMachO::participatesInCoalescing() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ // if image is loaded with RTLD_LOCAL, then its symbols' visibility
+ // is reduced and it can't coalesce with other images
+ if ( this->hasHiddenExports() )
+ return false;
+ return ( (mh->flags & (MH_WEAK_DEFINES|MH_BINDS_TO_WEAK)) != 0 );
+}
fSlide = slide;
}
-void ImageLoaderMachO::parseLoadCmds()
+void ImageLoaderMachO::loadCodeSignature(const struct linkedit_data_command* codeSigCmd, int fd, uint64_t offsetInFatFile, const LinkContext& context)
{
- // now that segments are mapped in, get real fMachOData, fLinkEditBase, and fSlide
- for (ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
- Segment* seg = *it;
- // set up pointer to __LINKEDIT segment
- if ( strcmp(seg->getName(),"__LINKEDIT") == 0 )
- fLinkEditBase = (uint8_t*)(seg->getActualLoadAddress(this) - seg->getFileOffset());
-#if TEXT_RELOC_SUPPORT
- // __TEXT segment always starts at beginning of file and contains mach_header and load commands
- if ( strcmp(seg->getName(),"__TEXT") == 0 ) {
- if ( ((SegmentMachO*)seg)->hasFixUps() )
- fTextSegmentWithFixups = (SegmentMachO*)seg;
+ // if dylib being loaded has no code signature load command
+ if ( codeSigCmd == NULL ) {
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+ bool codeSigningEnforced = context.codeSigningEnforced;
+ if ( context.mainExecutableCodeSigned && !codeSigningEnforced ) {
+ static bool codeSignEnforcementDynamicallyEnabled = false;
+ if ( !codeSignEnforcementDynamicallyEnabled ) {
+ uint32_t flags;
+ if ( csops(0, CS_OPS_STATUS, &flags, sizeof(flags)) != -1 ) {
+ if ( flags & CS_ENFORCEMENT ) {
+ codeSignEnforcementDynamicallyEnabled = true;
+ }
+ }
+ }
+ codeSigningEnforced = codeSignEnforcementDynamicallyEnabled;
+ }
+ // if we require dylibs to be code signed
+ if ( codeSigningEnforced ) {
+ // if there is a non-load command based code signature, use it
+ off_t offset = (off_t)offsetInFatFile;
+ if ( fcntl(fd, F_FINDSIGS, &offset, sizeof(offset)) != -1 )
+ return;
+ // otherwise gracefully return from dlopen()
+ dyld::throwf("required code signature missing for '%s'\n", this->getPath());
}
#endif
-#if __i386__
- if ( seg->readOnlyImportStubs() )
- fReadOnlyImportSegment = (SegmentMachO*)seg;
+ //Since we don't have a range for the signature we have to assume full coverage
+ fCoveredCodeLength = UINT64_MAX;
+ }
+ else {
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+ // <rdar://problem/13622786> ignore code signatures in binaries built with pre-10.9 tools
+ if ( this->sdkVersion() < DYLD_MACOSX_VERSION_10_9 ) {
+ return;
+ }
#endif
- // some segment always starts at beginning of file and contains mach_header and load commands
- if ( (seg->getFileOffset() == 0) && (seg->getFileSize() != 0) ) {
- fMachOData = (uint8_t*)(seg->getActualLoadAddress(this));
+ fsignatures_t siginfo;
+ siginfo.fs_file_start=offsetInFatFile; // start of mach-o slice in fat file
+ siginfo.fs_blob_start=(void*)(long)(codeSigCmd->dataoff); // start of CD in mach-o file
+ siginfo.fs_blob_size=codeSigCmd->datasize; // size of CD
+ int result = fcntl(fd, F_ADDFILESIGS_RETURN, &siginfo);
+
+#if TARGET_IPHONE_SIMULATOR
+ // rdar://problem/18759224> check range covered by the code directory after loading
+ // Attempt to fallback only if we are in the simulator
+
+ if ( result == -1 ) {
+ result = fcntl(fd, F_ADDFILESIGS, &siginfo);
+ siginfo.fs_file_start = codeSigCmd->dataoff;
}
- #if __ppc64__
- // in 10.5 to support images that span 4GB (including pagezero) switch meaning of r_address
- if ( ((seg->getPreferredLoadAddress() + seg->getSize() - fSegmentsArray[0].getPreferredLoadAddress()) > 0x100000000)
- && seg->writeable() )
- f4GBWritable = true;
- #endif
+#endif
+
+ if ( result == -1 ) {
+ if ( (errno == EPERM) || (errno == EBADEXEC) )
+ dyld::throwf("code signature invalid for '%s'\n", this->getPath());
+ if ( context.verboseCodeSignatures )
+ dyld::log("dyld: Failed registering code signature for %s, errno=%d\n", this->getPath(), errno);
+ siginfo.fs_file_start = UINT64_MAX;
+ } else if ( context.verboseCodeSignatures ) {
+ dyld::log("dyld: Registered code signature for %s\n", this->getPath());
+ }
+ fCoveredCodeLength = siginfo.fs_file_start;
}
-
- // keep count of prebound images with weak exports
- if ( this->hasCoalescedExports() )
- ++fgCountOfImagesWithWeakExports;
+}
- // keep count of images used in shared cache
- if ( fInSharedCache )
- ++fgImagesUsedFromSharedCache;
+void ImageLoaderMachO::validateFirstPages(const struct linkedit_data_command* codeSigCmd, int fd, const uint8_t *fileData, size_t lenFileData, off_t offsetInFat, const LinkContext& context)
+{
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+ // rdar://problem/21839703> 15A226d: dyld crashes in mageLoaderMachO::validateFirstPages during dlopen() after encountering an mmap failure
+ // We need to ignore older code signatures because they will be bad.
+ if ( this->sdkVersion() < DYLD_MACOSX_VERSION_10_9 ) {
+ return;
+ }
+#endif
+ if (codeSigCmd != NULL) {
+ if ( context.verboseMapping )
+ dyld::log("dyld: validate pages: %llu\n", (unsigned long long)offsetInFat);
+
+ void *fdata = xmmap(NULL, lenFileData, PROT_READ | PROT_EXEC, MAP_SHARED, fd, offsetInFat);
+ if ( fdata == MAP_FAILED ) {
+ if ( context.processRequiresLibraryValidation )
+ dyld::throwf("cannot load image with wrong team ID in process using Library Validation");
+ else
+ dyld::throwf("mmap() errno=%d validating first page of '%s'", errno, getInstallPath());
+ }
+ if ( memcmp(fdata, fileData, lenFileData) != 0 )
+ dyld::throwf("mmap() page compare failed for '%s'", getInstallPath());
+ munmap(fdata, lenFileData);
+ }
+}
- // walk load commands (mapped in at start of __TEXT segment)
+
+const char* ImageLoaderMachO::getInstallPath() const
+{
+ if ( fDylibIDOffset != 0 ) {
+ const dylib_command* dylibID = (dylib_command*)(&fMachOData[fDylibIDOffset]);
+ return (char*)dylibID + dylibID->dylib.name.offset;
+ }
+ return NULL;
+}
+
+void ImageLoaderMachO::registerInterposing()
+{
+ // mach-o files advertise interposing by having a __DATA __interpose section
+ struct InterposeData { uintptr_t replacement; uintptr_t replacee; };
const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
const struct load_command* cmd = cmds;
for (uint32_t i = 0; i < cmd_count; ++i) {
switch (cmd->cmd) {
- case LC_SYMTAB:
- {
- const struct symtab_command* symtab = (struct symtab_command*)cmd;
- fStrings = (const char*)&fLinkEditBase[symtab->stroff];
- fSymbolTable = (struct macho_nlist*)(&fLinkEditBase[symtab->symoff]);
- }
- break;
- case LC_DYSYMTAB:
- fDynamicInfo = (struct dysymtab_command*)cmd;
- break;
- case LC_SUB_UMBRELLA:
- fHasSubUmbrella = true;
- break;
- case LC_SUB_FRAMEWORK:
- fInUmbrella = true;
- break;
- case LC_SUB_LIBRARY:
- fHasSubLibraries = true;
- break;
- case LC_ROUTINES_COMMAND:
- fHasDashInit = true;
- break;
- case LC_SEGMENT_COMMAND:
+ case LC_SEGMENT_COMMAND:
{
const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
-#if IMAGE_NOTIFY_SUPPORT
- const bool isDataSeg = (strcmp(seg->segname, "__DATA") == 0);
-#endif
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_MOD_INIT_FUNC_POINTERS )
- fHasInitializers = true;
- else if ( type == S_MOD_TERM_FUNC_POINTERS )
- fHasTerminators = true;
- else if ( type == S_DTRACE_DOF )
- fHasDOFSections = true;
-#if IMAGE_NOTIFY_SUPPORT
- else if ( isDataSeg && (strcmp(sect->sectname, "__image_notify") == 0) )
- fHasImageNotifySection = true;
-#endif
+ if ( ((sect->flags & SECTION_TYPE) == S_INTERPOSING) || ((strcmp(sect->sectname, "__interpose") == 0) && (strcmp(seg->segname, "__DATA") == 0)) ) {
+ const InterposeData* interposeArray = (InterposeData*)(sect->addr + fSlide);
+ const size_t count = sect->size / sizeof(InterposeData);
+ for (size_t i=0; i < count; ++i) {
+ ImageLoader::InterposeTuple tuple;
+ tuple.replacement = interposeArray[i].replacement;
+ tuple.neverImage = this;
+ tuple.onlyImage = NULL;
+ tuple.replacee = interposeArray[i].replacee;
+ // <rdar://problem/7937695> verify that replacement is in this image
+ if ( this->containsAddress((void*)tuple.replacement) ) {
+ // chain to any existing interpositions
+ for (std::vector<InterposeTuple>::iterator it=fgInterposingTuples.begin(); it != fgInterposingTuples.end(); it++) {
+ if ( it->replacee == tuple.replacee ) {
+ tuple.replacee = it->replacement;
+ }
+ }
+ ImageLoader::fgInterposingTuples.push_back(tuple);
+ }
+ }
+ }
}
}
break;
- case LC_TWOLEVEL_HINTS:
- fTwoLevelHints = (struct twolevel_hints_command*)cmd;
- break;
- case LC_ID_DYLIB:
- {
- fDylibID = (struct dylib_command*)cmd;
- }
- break;
- case LC_RPATH:
- case LC_LOAD_WEAK_DYLIB:
- case LC_REEXPORT_DYLIB:
- // do nothing, just prevent LC_REQ_DYLD exception from occuring
- break;
- default:
- if ( (cmd->cmd & LC_REQ_DYLD) != 0 )
- dyld::throwf("unknown required load command 0x%08X", cmd->cmd);
}
cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
}
-
-
-
-const char* ImageLoaderMachO::getInstallPath() const
+uint32_t ImageLoaderMachO::sdkVersion() const
{
- if ( fDylibID != NULL ) {
- return (char*)fDylibID + fDylibID->dylib.name.offset;
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ const struct version_min_command* versCmd;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch ( cmd->cmd ) {
+ case LC_VERSION_MIN_MACOSX:
+ case LC_VERSION_MIN_IPHONEOS:
+ case LC_VERSION_MIN_TVOS:
+ case LC_VERSION_MIN_WATCHOS:
+ versCmd = (version_min_command*)cmd;
+ return versCmd->sdk;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
- return NULL;
+ return 0;
}
-// test if this image is re-exported through parent (the image that loaded this one)
-bool ImageLoaderMachO::isSubframeworkOf(const LinkContext& context, const ImageLoader* parent) const
+uint32_t ImageLoaderMachO::minOSVersion(const mach_header* mh)
{
- if ( fInUmbrella ) {
- const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
- const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
- const struct load_command* cmd = cmds;
- for (uint32_t i = 0; i < cmd_count; ++i) {
- if (cmd->cmd == LC_SUB_FRAMEWORK) {
- const struct sub_framework_command* subf = (struct sub_framework_command*)cmd;
- const char* exportThruName = (char*)cmd + subf->umbrella.offset;
- // need to match LC_SUB_FRAMEWORK string against the leaf name of the install location of parent...
- const char* parentInstallPath = parent->getInstallPath();
- if ( parentInstallPath != NULL ) {
- const char* lastSlash = strrchr(parentInstallPath, '/');
- if ( lastSlash != NULL ) {
- if ( strcmp(&lastSlash[1], exportThruName) == 0 )
- return true;
- if ( context.imageSuffix != NULL ) {
- // when DYLD_IMAGE_SUFFIX is used, lastSlash string needs imageSuffix removed from end
- char reexportAndSuffix[strlen(context.imageSuffix)+strlen(exportThruName)+1];
- strcpy(reexportAndSuffix, exportThruName);
- strcat(reexportAndSuffix, context.imageSuffix);
- if ( strcmp(&lastSlash[1], reexportAndSuffix) == 0 )
- return true;
- }
- }
- }
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ 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 version_min_command* versCmd;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch ( cmd->cmd ) {
+ case LC_VERSION_MIN_MACOSX:
+ case LC_VERSION_MIN_IPHONEOS:
+ case LC_VERSION_MIN_TVOS:
+ case LC_VERSION_MIN_WATCHOS:
+ versCmd = (version_min_command*)cmd;
+ return versCmd->version;
}
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
- return false;
+ return 0;
}
-// test if child is re-exported
-bool ImageLoaderMachO::hasSubLibrary(const LinkContext& context, const ImageLoader* child) const
+uint32_t ImageLoaderMachO::minOSVersion() const
{
- if ( fHasSubLibraries ) {
- // need to match LC_SUB_LIBRARY string against the leaf name (without extension) of the install location of child...
- const char* childInstallPath = child->getInstallPath();
- if ( childInstallPath != NULL ) {
- const char* lastSlash = strrchr(childInstallPath, '/');
- if ( lastSlash != NULL ) {
- const char* firstDot = strchr(lastSlash, '.');
- int len;
- if ( firstDot == NULL )
- len = strlen(lastSlash);
- else
- len = firstDot-lastSlash-1;
- char childLeafName[len+1];
- strncpy(childLeafName, &lastSlash[1], len);
- childLeafName[len] = '\0';
- const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
- const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
- const struct load_command* cmd = cmds;
- for (uint32_t i = 0; i < cmd_count; ++i) {
- switch (cmd->cmd) {
- case LC_SUB_LIBRARY:
- {
- const struct sub_library_command* lib = (struct sub_library_command*)cmd;
- const char* aSubLibName = (char*)cmd + lib->sub_library.offset;
- if ( strcmp(aSubLibName, childLeafName) == 0 )
- return true;
- if ( context.imageSuffix != NULL ) {
- // when DYLD_IMAGE_SUFFIX is used, childLeafName string needs imageSuffix removed from end
- char aSubLibNameAndSuffix[strlen(context.imageSuffix)+strlen(aSubLibName)+1];
- strcpy(aSubLibNameAndSuffix, aSubLibName);
- strcat(aSubLibNameAndSuffix, context.imageSuffix);
- if ( strcmp(aSubLibNameAndSuffix, childLeafName) == 0 )
- return true;
- }
- }
- break;
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
- }
- }
- }
- if ( fHasSubUmbrella ) {
- // need to match LC_SUB_UMBRELLA string against the leaf name of install location of child...
- const char* childInstallPath = child->getInstallPath();
- if ( childInstallPath != NULL ) {
- const char* lastSlash = strrchr(childInstallPath, '/');
- if ( lastSlash != NULL ) {
- const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
- const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
- const struct load_command* cmd = cmds;
- for (uint32_t i = 0; i < cmd_count; ++i) {
- switch (cmd->cmd) {
- case LC_SUB_UMBRELLA:
- {
- const struct sub_umbrella_command* um = (struct sub_umbrella_command*)cmd;
- const char* aSubUmbrellaName = (char*)cmd + um->sub_umbrella.offset;
- if ( strcmp(aSubUmbrellaName, &lastSlash[1]) == 0 )
- return true;
- if ( context.imageSuffix != NULL ) {
- // when DYLD_IMAGE_SUFFIX is used, lastSlash string needs imageSuffix removed from end
- char umbrellaAndSuffix[strlen(context.imageSuffix)+strlen(aSubUmbrellaName)+1];
- strcpy(umbrellaAndSuffix, aSubUmbrellaName);
- strcat(umbrellaAndSuffix, context.imageSuffix);
- if ( strcmp(umbrellaAndSuffix, &lastSlash[1]) == 0 )
- return true;
- }
- }
- break;
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
- }
+ return ImageLoaderMachO::minOSVersion(machHeader());
+}
+
+
+void* ImageLoaderMachO::getThreadPC() const
+{
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd == LC_MAIN ) {
+ entry_point_command* mainCmd = (entry_point_command*)cmd;
+ void* entry = (void*)(mainCmd->entryoff + (char*)fMachOData);
+ // <rdar://problem/8543820&9228031> verify entry point is in image
+ if ( this->containsAddress(entry) )
+ return entry;
+ else
+ throw "LC_MAIN entryoff is out of range";
}
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
- return false;
+ return NULL;
}
-
void* ImageLoaderMachO::getMain() const
{
const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
const struct load_command* cmd = cmds;
- for (unsigned long i = 0; i < cmd_count; ++i) {
+ for (uint32_t i = 0; i < cmd_count; ++i) {
switch (cmd->cmd) {
case LC_UNIXTHREAD:
{
- #if __ppc__
- const ppc_thread_state_t* registers = (ppc_thread_state_t*)(((char*)cmd) + 16);
- return (void*)(registers->srr0 + fSlide);
- #elif __ppc64__
- const ppc_thread_state64_t* registers = (ppc_thread_state64_t*)(((char*)cmd) + 16);
- return (void*)(registers->srr0 + fSlide);
- #elif __i386__
+ #if __i386__
const i386_thread_state_t* registers = (i386_thread_state_t*)(((char*)cmd) + 16);
- return (void*)(registers->eip + fSlide);
+ void* entry = (void*)(registers->eip + fSlide);
#elif __x86_64__
const x86_thread_state64_t* registers = (x86_thread_state64_t*)(((char*)cmd) + 16);
- return (void*)(registers->rip + fSlide);
+ void* entry = (void*)(registers->rip + fSlide);
+ #elif __arm__
+ const arm_thread_state_t* registers = (arm_thread_state_t*)(((char*)cmd) + 16);
+ void* entry = (void*)(registers->__pc + fSlide);
+ #elif __arm64__
+ const arm_thread_state64_t* registers = (arm_thread_state64_t*)(((char*)cmd) + 16);
+ void* entry = (void*)(registers->__pc + fSlide);
#else
#warning need processor specific code
#endif
+ // <rdar://problem/8543820&9228031> verify entry point is in image
+ if ( this->containsAddress(entry) ) {
+ return entry;
+ }
}
break;
}
cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
- return NULL;
+ throw "no valid entry point";
}
-
-uint32_t ImageLoaderMachO::doGetDependentLibraryCount()
+bool ImageLoaderMachO::needsAddedLibSystemDepency(unsigned int libCount, const macho_header* mh)
{
- const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
- const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
- uint32_t count = 0;
+ // <rdar://problem/6357561> ensure that every image depends on something which depends on libSystem
+ if ( libCount > 1 )
+ return false;
+
+ // <rdar://problem/6409800> dyld implicit-libSystem breaks valgrind
+ if ( mh->filetype == MH_EXECUTE )
+ return false;
+
+ bool isNonOSdylib = false;
+ const uint32_t cmd_count = mh->ncmds;
+ const struct load_command* const cmds = (struct load_command*)((uint8_t*)mh+sizeof(macho_header));
const struct load_command* cmd = cmds;
- for (unsigned long i = 0; i < cmd_count; ++i) {
+ for (uint32_t i = 0; i < cmd_count; ++i) {
switch (cmd->cmd) {
case LC_LOAD_DYLIB:
case LC_LOAD_WEAK_DYLIB:
case LC_REEXPORT_DYLIB:
- ++count;
+ case LC_LOAD_UPWARD_DYLIB:
+ return false;
+ case LC_ID_DYLIB:
+ {
+ const dylib_command* dylibID = (dylib_command*)cmd;
+ const char* installPath = (char*)cmd + dylibID->dylib.name.offset;
+ // It is OK for OS dylibs (libSystem or libmath or Rosetta shims) to have no dependents
+ // but all other dylibs must depend on libSystem for initialization to initialize libSystem first
+ // <rdar://problem/6497528> rosetta circular dependency spew
+ isNonOSdylib = ( (strncmp(installPath, "/usr/lib/", 9) != 0) && (strncmp(installPath, "/usr/libexec/oah/Shims", 9) != 0) );
+ }
break;
}
cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
- return count;
+ return isNonOSdylib;
}
+
void ImageLoaderMachO::doGetDependentLibraries(DependentLibraryInfo libs[])
{
- uint32_t index = 0;
- const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
- const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
- const struct load_command* cmd = cmds;
- for (unsigned long i = 0; i < cmd_count; ++i) {
- switch (cmd->cmd) {
- case LC_LOAD_DYLIB:
- case LC_LOAD_WEAK_DYLIB:
- case LC_REEXPORT_DYLIB:
- {
- const struct dylib_command* dylib = (struct dylib_command*)cmd;
- DependentLibraryInfo* lib = &libs[index++];
- lib->name = (char*)cmd + dylib->dylib.name.offset;
- //lib->name = strdup((char*)cmd + dylib->dylib.name.offset);
- lib->info.checksum = dylib->dylib.timestamp;
- lib->info.minVersion = dylib->dylib.compatibility_version;
- lib->info.maxVersion = dylib->dylib.current_version;
- lib->required = (cmd->cmd != LC_LOAD_WEAK_DYLIB);
- lib->reExported = (cmd->cmd == LC_REEXPORT_DYLIB);
+ if ( needsAddedLibSystemDepency(libraryCount(), (macho_header*)fMachOData) ) {
+ DependentLibraryInfo* lib = &libs[0];
+ lib->name = "/usr/lib/libSystem.B.dylib";
+ lib->info.checksum = 0;
+ lib->info.minVersion = 0;
+ lib->info.maxVersion = 0;
+ lib->required = false;
+ lib->reExported = false;
+ lib->upward = false;
+ }
+ else {
+ uint32_t index = 0;
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_LOAD_DYLIB:
+ case LC_LOAD_WEAK_DYLIB:
+ case LC_REEXPORT_DYLIB:
+ case LC_LOAD_UPWARD_DYLIB:
+ {
+ const struct dylib_command* dylib = (struct dylib_command*)cmd;
+ DependentLibraryInfo* lib = &libs[index++];
+ lib->name = (char*)cmd + dylib->dylib.name.offset;
+ //lib->name = strdup((char*)cmd + dylib->dylib.name.offset);
+ lib->info.checksum = dylib->dylib.timestamp;
+ lib->info.minVersion = dylib->dylib.compatibility_version;
+ lib->info.maxVersion = dylib->dylib.current_version;
+ lib->required = (cmd->cmd != LC_LOAD_WEAK_DYLIB);
+ lib->reExported = (cmd->cmd == LC_REEXPORT_DYLIB);
+ lib->upward = (cmd->cmd == LC_LOAD_UPWARD_DYLIB);
+ }
+ break;
}
- break;
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
}
ImageLoader::LibraryInfo ImageLoaderMachO::doGetLibraryInfo()
{
LibraryInfo info;
- if ( fDylibID != NULL ) {
- info.minVersion = fDylibID->dylib.compatibility_version;
- info.maxVersion = fDylibID->dylib.current_version;
- info.checksum = fDylibID->dylib.timestamp;
+ if ( fDylibIDOffset != 0 ) {
+ const dylib_command* dylibID = (dylib_command*)(&fMachOData[fDylibIDOffset]);
+ info.minVersion = dylibID->dylib.compatibility_version;
+ info.maxVersion = dylibID->dylib.current_version;
+ info.checksum = dylibID->dylib.timestamp;
}
else {
info.minVersion = 0;
const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
const struct load_command* cmd = cmds;
- for (unsigned long i = 0; i < cmd_count; ++i) {
+ for (uint32_t i = 0; i < cmd_count; ++i) {
switch (cmd->cmd) {
case LC_RPATH:
+ const char* pathToAdd = NULL;
const char* path = (char*)cmd + ((struct rpath_command*)cmd)->path.offset;
- if ( strncmp(path, "@loader_path/", 13) == 0 ) {
- if ( issetugid() && (context.mainExecutable == this) ) {
- dyld::warn("LC_RPATH %s in %s being ignored in setuid program because of @loader_path\n", path, this->getPath());
+ if ( (strncmp(path, "@loader_path", 12) == 0) && ((path[12] == '/') || (path[12] == '\0')) ) {
+ if ( context.processIsRestricted && !context.processRequiresLibraryValidation && (context.mainExecutable == this) ) {
+ dyld::warn("LC_RPATH %s in %s being ignored in restricted program because of @loader_path\n", path, this->getPath());
break;
}
char resolvedPath[PATH_MAX];
char newRealPath[strlen(resolvedPath) + strlen(path)];
strcpy(newRealPath, resolvedPath);
char* addPoint = strrchr(newRealPath,'/');
- if ( addPoint != NULL )
- strcpy(&addPoint[1], &path[13]);
- else
- strcpy(newRealPath, &path[13]);
- path = strdup(newRealPath);
+ if ( addPoint != NULL ) {
+ strcpy(addPoint, &path[12]);
+ pathToAdd = strdup(newRealPath);
+ }
}
}
- else if ( strncmp(path, "@executable_path/", 17) == 0 ) {
- if ( issetugid() ) {
- dyld::warn("LC_RPATH %s in %s being ignored in setuid program because of @executable_path\n", path, this->getPath());
+ else if ( (strncmp(path, "@executable_path", 16) == 0) && ((path[16] == '/') || (path[16] == '\0')) ) {
+ if ( context.processIsRestricted && !context.processRequiresLibraryValidation ) {
+ dyld::warn("LC_RPATH %s in %s being ignored in restricted program because of @executable_path\n", path, this->getPath());
break;
}
char resolvedPath[PATH_MAX];
char newRealPath[strlen(resolvedPath) + strlen(path)];
strcpy(newRealPath, resolvedPath);
char* addPoint = strrchr(newRealPath,'/');
- if ( addPoint != NULL )
- strcpy(&addPoint[1], &path[17]);
- else
- strcpy(newRealPath, &path[17]);
- path = strdup(newRealPath);
+ if ( addPoint != NULL ) {
+ strcpy(addPoint, &path[16]);
+ pathToAdd = strdup(newRealPath);
+ }
}
}
- else if ( (path[0] != '/') && issetugid() ) {
- dyld::warn("LC_RPATH %s in %s being ignored in setuid program because it is a relative path\n", path, this->getPath());
+ else if ( (path[0] != '/') && context.processIsRestricted && !context.processRequiresLibraryValidation ) {
+ dyld::warn("LC_RPATH %s in %s being ignored in restricted program because it is a relative path\n", path, this->getPath());
break;
}
+ else if ( (path[0] == '/') && (context.rootPaths != NULL) ) {
+ // <rdar://problem/5869973> DYLD_ROOT_PATH should apply to LC_RPATH rpaths
+ // DYLD_ROOT_PATH can be a list of paths, but at this point we can only support one, so use first combination that exists
+ bool found = false;
+ for(const char** rp = context.rootPaths; *rp != NULL; ++rp) {
+ char newPath[PATH_MAX];
+ strlcpy(newPath, *rp, PATH_MAX);
+ strlcat(newPath, path, PATH_MAX);
+ struct stat stat_buf;
+ if ( stat(newPath, &stat_buf) != -1 ) {
+ //dyld::log("combined DYLD_ROOT_PATH and LC_RPATH: %s\n", newPath);
+ pathToAdd = strdup(newPath);
+ found = true;
+ break;
+ }
+ }
+ if ( ! found ) {
+ // make copy so that all elements of 'paths' can be freed
+ pathToAdd = strdup(path);
+ }
+ }
else {
// make copy so that all elements of 'paths' can be freed
- path = strdup(path);
+ pathToAdd = strdup(path);
}
- paths.push_back(path);
+ if ( pathToAdd != NULL )
+ paths.push_back(pathToAdd);
break;
}
cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
}
-uintptr_t ImageLoaderMachO::getFirstWritableSegmentAddress()
-{
- // in split segment libraries r_address is offset from first writable segment
- for(ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
- Segment* seg = *it;
- if ( seg->writeable() )
- return seg->getActualLoadAddress(this);
- }
- throw "no writable segment";
-}
-
-uintptr_t ImageLoaderMachO::getRelocBase()
-{
- // r_address is either an offset from the first segment address
- // or from the first writable segment address
-#if __ppc__ || __i386__
- if ( fIsSplitSeg )
- return getFirstWritableSegmentAddress();
- else
- return fSegmentsArray[0].getActualLoadAddress(this);
-#elif __ppc64__
- if ( f4GBWritable )
- return getFirstWritableSegmentAddress();
- else
- return fSegmentsArray[0].getActualLoadAddress(this);
-#elif __x86_64__
- return getFirstWritableSegmentAddress();
-#endif
-}
-
-#if __ppc__
-static inline void otherRelocsPPC(uintptr_t* locationToFix, uint8_t relocationType, uint16_t otherHalf, uintptr_t slide)
+bool ImageLoaderMachO::getUUID(uuid_t uuid) const
{
- // low 16 bits of 32-bit ppc instructions need fixing
- struct ppcInstruction { uint16_t opcode; int16_t immediateValue; };
- ppcInstruction* instruction = (ppcInstruction*)locationToFix;
- //uint32_t before = *((uint32_t*)locationToFix);
- switch ( relocationType )
- {
- case PPC_RELOC_LO16:
- instruction->immediateValue = ((otherHalf << 16) | instruction->immediateValue) + slide;
- break;
- case PPC_RELOC_HI16:
- instruction->immediateValue = ((((instruction->immediateValue << 16) | otherHalf) + slide) >> 16);
- break;
- case PPC_RELOC_HA16:
- int16_t signedOtherHalf = (int16_t)(otherHalf & 0xffff);
- uint32_t temp = (instruction->immediateValue << 16) + signedOtherHalf + slide;
- if ( (temp & 0x00008000) != 0 )
- temp += 0x00008000;
- instruction->immediateValue = temp >> 16;
- }
- //uint32_t after = *((uint32_t*)locationToFix);
- //dyld::log("dyld: ppc fixup %0p type %d from 0x%08X to 0x%08X\n", locationToFix, relocationType, before, after);
-}
-#endif
-
-#if __ppc__ || __i386__
-void ImageLoaderMachO::resetPreboundLazyPointers(const LinkContext& context, uintptr_t relocBase)
-{
- // loop through all local (internal) relocation records looking for pre-bound-lazy-pointer values
- register const uintptr_t slide = this->fSlide;
- const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->locreloff]);
- const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nlocrel];
- for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
- if ( (reloc->r_address & R_SCATTERED) != 0 ) {
- const struct scattered_relocation_info* sreloc = (struct scattered_relocation_info*)reloc;
- if (sreloc->r_length == RELOC_SIZE) {
- uintptr_t* locationToFix = (uintptr_t*)(sreloc->r_address + relocBase);
- switch(sreloc->r_type) {
- #if __ppc__
- case PPC_RELOC_PB_LA_PTR:
- *locationToFix = sreloc->r_value + slide;
- break;
- #endif
- #if __i386__
- case GENERIC_RELOC_PB_LA_PTR:
- *locationToFix = sreloc->r_value + slide;
- break;
- #endif
- }
- }
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_UUID:
+ uuid_command* uc = (uuid_command*)cmd;
+ memcpy(uuid, uc->uuid, 16);
+ return true;
}
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
+ bzero(uuid, 16);
+ return false;
}
-#endif
void ImageLoaderMachO::doRebase(const LinkContext& context)
{
++fgImagesWithUsedPrebinding; // bump totals for statistics
return;
}
-
+
// print why prebinding was not used
if ( context.verbosePrebinding ) {
if ( !this->isPrebindable() ) {
}
}
- // cache values that are used in the following loop
- const uintptr_t relocBase = this->getRelocBase();
- register const uintptr_t slide = this->fSlide;
-
//dyld::log("slide=0x%08lX for %s\n", slide, this->getPath());
-#if __ppc__ || __i386__
+#if PREBOUND_IMAGE_SUPPORT
// if prebound and we got here, then prebinding is not valid, so reset all lazy pointers
// if this image is in the shared cache, do not reset, they will be bound in doBind()
if ( this->isPrebindable() && !fInSharedCache )
- this->resetPreboundLazyPointers(context, relocBase);
+ this->resetPreboundLazyPointers(context);
#endif
- // if in shared cache and got here, then we depend on something not in the shared cache
- if ( fInSharedCache )
- context.notifySharedCacheInvalid();
-
// if loaded at preferred address, no rebasing necessary
- if ( slide == 0 )
+ if ( this->fSlide == 0 )
return;
#if TEXT_RELOC_SUPPORT
// if there are __TEXT fixups, temporarily make __TEXT writable
- if ( fTextSegmentWithFixups != NULL )
- fTextSegmentWithFixups->tempWritable(context, this);
-#endif
- // loop through all local (internal) relocation records
- const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->locreloff]);
- const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nlocrel];
- for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
-#if LINKEDIT_USAGE_DEBUG
- noteAccessedLinkEditAddress(reloc);
+ if ( fTextSegmentRebases )
+ this->makeTextSegmentWritable(context, true);
#endif
- #if __x86_64__
- // only one kind of local relocation supported for x86_64
- if ( reloc->r_length != 3 )
- throw "bad local relocation length";
- if ( reloc->r_type != X86_64_RELOC_UNSIGNED )
- throw "unknown local relocation type";
- if ( reloc->r_pcrel != 0 )
- throw "bad local relocation pc_rel";
- if ( reloc->r_extern != 0 )
- throw "extern relocation found with local relocations";
- *((uintptr_t*)(reloc->r_address + relocBase)) += slide;
- #else
- if ( (reloc->r_address & R_SCATTERED) == 0 ) {
- if ( reloc->r_symbolnum == R_ABS ) {
- // ignore absolute relocations
- }
- else if (reloc->r_length == RELOC_SIZE) {
- switch(reloc->r_type) {
- case GENERIC_RELOC_VANILLA:
- *((uintptr_t*)(reloc->r_address + relocBase)) += slide;
- break;
- #if __ppc__
- case PPC_RELOC_HI16:
- case PPC_RELOC_LO16:
- case PPC_RELOC_HA16:
- // some tools leave object file relocations in linked images
- otherRelocsPPC((uintptr_t*)(reloc->r_address + relocBase), reloc->r_type, reloc[1].r_address, slide);
- ++reloc; // these relocations come in pairs, skip next
- break;
- #endif
- default:
- throw "unknown local relocation type";
- }
- }
- else {
- throw "bad local relocation length";
- }
- }
- else {
- const struct scattered_relocation_info* sreloc = (struct scattered_relocation_info*)reloc;
- if (sreloc->r_length == RELOC_SIZE) {
- uintptr_t* locationToFix = (uintptr_t*)(sreloc->r_address + relocBase);
- switch(sreloc->r_type) {
- case GENERIC_RELOC_VANILLA:
- *locationToFix += slide;
- break;
- #if __ppc__
- case PPC_RELOC_HI16:
- case PPC_RELOC_LO16:
- case PPC_RELOC_HA16:
- // Metrowerks compiler sometimes leaves object file relocations in linked images???
- ++reloc; // these relocations come in pairs, get next one
- otherRelocsPPC(locationToFix, sreloc->r_type, reloc->r_address, slide);
- break;
- case PPC_RELOC_PB_LA_PTR:
- // do nothing
- break;
- #elif __ppc64__
- case PPC_RELOC_PB_LA_PTR:
- // needed for compatibility with ppc64 binaries built with the first ld64
- // which used PPC_RELOC_PB_LA_PTR relocs instead of GENERIC_RELOC_VANILLA for lazy pointers
- *locationToFix += slide;
- break;
- #elif __i386__
- case GENERIC_RELOC_PB_LA_PTR:
- // do nothing
- break;
- #endif
- default:
- throw "unknown local scattered relocation type";
- }
- }
- else {
- throw "bad local scattered relocation length";
- }
- }
- #endif // x86_64
- }
-
+
+ // do actual rebasing
+ this->rebase(context);
+
#if TEXT_RELOC_SUPPORT
// if there were __TEXT fixups, restore write protection
- if ( fTextSegmentWithFixups != NULL ) {
- fTextSegmentWithFixups->setPermissions(context,this);
- sys_icache_invalidate((void*)fTextSegmentWithFixups->getActualLoadAddress(this), fTextSegmentWithFixups->getSize());
- }
+ if ( fTextSegmentRebases )
+ this->makeTextSegmentWritable(context, false);
+
#endif
- // update stats
- fgTotalRebaseFixups += fDynamicInfo->nlocrel;
}
-
-const struct macho_nlist* ImageLoaderMachO::binarySearchWithToc(const char* key, const char stringPool[], const struct macho_nlist symbols[],
- const struct dylib_table_of_contents toc[], uint32_t symbolCount, uint32_t hintIndex) const
+#if TEXT_RELOC_SUPPORT
+void ImageLoaderMachO::makeTextSegmentWritable(const LinkContext& context, bool writeable)
{
- int32_t high = symbolCount-1;
- int32_t mid = hintIndex;
-
- // handle out of range hint
- if ( mid >= (int32_t)symbolCount ) {
- mid = symbolCount/2;
- ++ImageLoaderMachO::fgUnhintedBinaryTreeSearchs;
- }
- else {
- ++ImageLoaderMachO::fgHintedBinaryTreeSearchs;
- }
- ++fgTotalBindImageSearches;
-
- //dyld::log("dyld: binarySearchWithToc for %s in %s\n", key, this->getShortName());
-
- for (int32_t low = 0; low <= high; mid = (low+high)/2) {
- const uint32_t index = toc[mid].symbol_index;
- const struct macho_nlist* pivot = &symbols[index];
- const char* pivotStr = &stringPool[pivot->n_un.n_strx];
-#if LINKEDIT_USAGE_DEBUG
- noteAccessedLinkEditAddress(&toc[mid]);
- noteAccessedLinkEditAddress(pivot);
- noteAccessedLinkEditAddress(pivotStr);
-#endif
- int cmp = astrcmp(key, pivotStr);
- if ( cmp == 0 )
- return pivot;
- if ( cmp > 0 ) {
- // key > pivot
- low = mid + 1;
- }
- else {
- // key < pivot
- high = mid - 1;
+ for(unsigned int i=0; i < fSegmentsCount; ++i) {
+ if ( segExecutable(i) ) {
+ if ( writeable ) {
+ segMakeWritable(i, context);
+ }
+ else {
+ #if !__i386__ && !__x86_64__
+ // some processors require range to be invalidated before it is made executable
+ sys_icache_invalidate((void*)segActualLoadAddress(i), segSize(textSegmentIndex));
+ #endif
+ segProtect(i, context);
+ }
}
}
- return NULL;
-}
-const struct macho_nlist* ImageLoaderMachO::binarySearch(const char* key, const char stringPool[], const struct macho_nlist symbols[], uint32_t symbolCount) const
-{
- // update stats
- ++fgTotalBindImageSearches;
- ++ImageLoaderMachO::fgUnhintedBinaryTreeSearchs;
-
- //dyld::log("dyld: binarySearch for %s in %s, stringpool=%p, symbols=%p, symbolCount=%u\n",
- // key, this->getShortName(), stringPool, symbols, symbolCount);
-
- const struct macho_nlist* base = symbols;
- for (uint32_t n = symbolCount; n > 0; n /= 2) {
- const struct macho_nlist* pivot = &base[n/2];
- const char* pivotStr = &stringPool[pivot->n_un.n_strx];
-#if LINKEDIT_USAGE_DEBUG
- noteAccessedLinkEditAddress(pivot);
- noteAccessedLinkEditAddress(pivotStr);
-#endif
- int cmp = astrcmp(key, pivotStr);
- if ( cmp == 0 )
- return pivot;
- if ( cmp > 0 ) {
- // key > pivot
- // move base to symbol after pivot
- base = &pivot[1];
- --n;
- }
- else {
- // key < pivot
- // keep same base
- }
- }
- return NULL;
}
+#endif
-const ImageLoader::Symbol* ImageLoaderMachO::findExportedSymbol(const char* name, const void* hint, bool searchReExports, const ImageLoader** foundIn) const
+const ImageLoader::Symbol* ImageLoaderMachO::findExportedSymbol(const char* name, bool searchReExports, const ImageLoader** foundIn) const
{
- const struct macho_nlist* sym = NULL;
- const struct twolevel_hint* theHint = (struct twolevel_hint*)hint;
- if ( fDynamicInfo->tocoff == 0 )
- sym = binarySearch(name, fStrings, &fSymbolTable[fDynamicInfo->iextdefsym], fDynamicInfo->nextdefsym);
- else {
- uint32_t start = fDynamicInfo->nextdefsym;
- if ( theHint != NULL )
- start = theHint->itoc;
- if ( (theHint == NULL) || (theHint->isub_image == 0) ) {
- sym = binarySearchWithToc(name, fStrings, fSymbolTable, (dylib_table_of_contents*)&fLinkEditBase[fDynamicInfo->tocoff],
- fDynamicInfo->ntoc, start);
- }
- }
- if ( sym != NULL ) {
- if ( foundIn != NULL )
- *foundIn = (ImageLoader*)this;
-
- return (const Symbol*)sym;
- }
+ // look in this image first
+ const ImageLoader::Symbol* result = this->findExportedSymbol(name, foundIn);
+ if ( result != NULL )
+ return result;
if ( searchReExports ) {
- // hint might tell us to try a particular subimage
- if ( (theHint != NULL) && (theHint->isub_image > 0) && (theHint->isub_image <= fLibrariesCount) ) {
- // isub_image is an index into a list that is sorted non-rexported images first
- uint32_t index = 0;
- ImageLoader* target = NULL;
- // pass one, only look at sub-frameworks
- for (uint32_t i=0; i < fLibrariesCount; ++i) {
- DependentLibrary& libInfo = fLibraries[i];
- if ( libInfo.isSubFramework && (libInfo.image != NULL)) {
- if ( ++index == theHint->isub_image ) {
- target = libInfo.image;
- break;
- }
- }
- }
- if (target != NULL) {
- // pass two, only look at non-sub-framework-reexports
- for (uint32_t i=0; i < fLibrariesCount; ++i) {
- DependentLibrary& libInfo = fLibraries[i];
- if ( libInfo.isReExported && !libInfo.isSubFramework && (libInfo.image != NULL) ) {
- if ( ++index == theHint->isub_image ) {
- target = libInfo.image;
- break;
- }
- }
+ for(unsigned int i=0; i < libraryCount(); ++i){
+ if ( libReExported(i) ) {
+ ImageLoader* image = libImage(i);
+ if ( image != NULL ) {
+ const Symbol* result = image->findExportedSymbol(name, searchReExports, foundIn);
+ if ( result != NULL )
+ return result;
}
}
- if (target != NULL) {
- const Symbol* result = target->findExportedSymbol(name, NULL, searchReExports, foundIn);
- if ( result != NULL )
- return result;
- }
- }
-
- // hint failed, try all sub images
- // pass one, only look at sub-frameworks
- for(unsigned int i=0; i < fLibrariesCount; ++i){
- DependentLibrary& libInfo = fLibraries[i];
- if ( (libInfo.image != NULL) && libInfo.isSubFramework ) {
- const Symbol* result = libInfo.image->findExportedSymbol(name, NULL, searchReExports, foundIn);
- if ( result != NULL )
- return result;
- }
- }
- // pass two, only look at non-sub-framework-reexports
- for(unsigned int i=0; i < fLibrariesCount; ++i){
- DependentLibrary& libInfo = fLibraries[i];
- if ( (libInfo.image != NULL) && libInfo.isReExported && !libInfo.isSubFramework ) {
- const Symbol* result = libInfo.image->findExportedSymbol(name, NULL, searchReExports, foundIn);
- if ( result != NULL )
- return result;
- }
}
}
- // last change: the hint is wrong (non-zero but actually in this image)
- if ( (theHint != NULL) && (theHint->isub_image != 0) ) {
- sym = binarySearchWithToc(name, fStrings, fSymbolTable, (dylib_table_of_contents*)&fLinkEditBase[fDynamicInfo->tocoff],
- fDynamicInfo->ntoc, fDynamicInfo->nextdefsym);
- if ( sym != NULL ) {
- if ( foundIn != NULL )
- *foundIn = (ImageLoader*)this;
- return (const Symbol*)sym;
- }
- }
-
return NULL;
}
-
-uintptr_t ImageLoaderMachO::getExportedSymbolAddress(const Symbol* sym, const LinkContext& context, const ImageLoader* requestor) const
+uintptr_t ImageLoaderMachO::getExportedSymbolAddress(const Symbol* sym, const LinkContext& context,
+ const ImageLoader* requestor, bool runResolver) const
{
- return this->getSymbolAddress((const struct macho_nlist*)sym, requestor, context);
+ return this->getSymbolAddress(sym, requestor, context, runResolver);
}
-uintptr_t ImageLoaderMachO::getSymbolAddress(const struct macho_nlist* sym, const ImageLoader* requestor, const LinkContext& context) const
+uintptr_t ImageLoaderMachO::getSymbolAddress(const Symbol* sym, const ImageLoader* requestor,
+ const LinkContext& context, bool runResolver) const
{
- uintptr_t result = sym->n_value + fSlide;
+ uintptr_t result = exportedSymbolAddress(context, sym, requestor, runResolver);
+ // check for interposing overrides
+ result = interposedAddress(context, result, requestor);
return result;
}
ImageLoader::DefinitionFlags ImageLoaderMachO::getExportedSymbolInfo(const Symbol* sym) const
{
- const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
- if ( (nlistSym->n_desc & N_WEAK_DEF) != 0 )
+ if ( exportedSymbolIsWeakDefintion(sym) )
return kWeakDefinition;
- return kNoDefinitionOptions;
+ else
+ return kNoDefinitionOptions;
}
const char* ImageLoaderMachO::getExportedSymbolName(const Symbol* sym) const
{
- const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
- return &fStrings[nlistSym->n_un.n_strx];
+ return exportedSymbolName(sym);
}
uint32_t ImageLoaderMachO::getExportedSymbolCount() const
{
- return fDynamicInfo->nextdefsym;
+ return exportedSymbolCount();
}
const ImageLoader::Symbol* ImageLoaderMachO::getIndexedExportedSymbol(uint32_t index) const
{
- if ( index < fDynamicInfo->nextdefsym ) {
- const struct macho_nlist* sym = &fSymbolTable[fDynamicInfo->iextdefsym + index];
- return (const ImageLoader::Symbol*)sym;
- }
- return NULL;
+ return exportedSymbolIndexed(index);
}
uint32_t ImageLoaderMachO::getImportedSymbolCount() const
{
- return fDynamicInfo->nundefsym;
+ return importedSymbolCount();
}
const ImageLoader::Symbol* ImageLoaderMachO::getIndexedImportedSymbol(uint32_t index) const
{
- if ( index < fDynamicInfo->nundefsym ) {
- const struct macho_nlist* sym = &fSymbolTable[fDynamicInfo->iundefsym + index];
- return (const ImageLoader::Symbol*)sym;
- }
- return NULL;
+ return importedSymbolIndexed(index);
}
-ImageLoader::ReferenceFlags ImageLoaderMachO::geImportedSymbolInfo(const ImageLoader::Symbol* sym) const
+ImageLoader::ReferenceFlags ImageLoaderMachO::getImportedSymbolInfo(const ImageLoader::Symbol* sym) const
{
- const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
ImageLoader::ReferenceFlags flags = kNoReferenceOptions;
- if ( ((nlistSym->n_type & N_TYPE) == N_UNDF) && (nlistSym->n_value != 0) )
- flags |= ImageLoader::kTentativeDefinition;
- if ( (nlistSym->n_desc & N_WEAK_REF) != 0 )
- flags |= ImageLoader::kWeakReference;
return flags;
}
const char* ImageLoaderMachO::getImportedSymbolName(const ImageLoader::Symbol* sym) const
{
- const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
- return &fStrings[nlistSym->n_un.n_strx];
+ return importedSymbolName(sym);
}
if ( (strcmp(sect->segname, segmentName) == 0) && (strcmp(sect->sectname, sectionName) == 0) ) {
*start = (uintptr_t*)(sect->addr + fSlide);
*length = sect->size;
- return true;
- }
- }
- }
- break;
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
- return false;
-}
-
-
-bool ImageLoaderMachO::findSection(const void* imageInterior, const char** segmentName, const char** sectionName, size_t* sectionOffset)
-{
- const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
- const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
- const struct load_command* cmd = cmds;
- const uintptr_t unslidInteriorAddress = (uintptr_t)imageInterior - this->getSlide();
- 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 ( (unslidInteriorAddress >= seg->vmaddr) && (unslidInteriorAddress < (seg->vmaddr+seg->vmsize)) ) {
- 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) {
- if ((sect->addr <= unslidInteriorAddress) && (unslidInteriorAddress < (sect->addr+sect->size))) {
- if ( segmentName != NULL )
- *segmentName = sect->segname;
- if ( sectionName != NULL )
- *sectionName = sect->sectname;
- if ( sectionOffset != NULL )
- *sectionOffset = unslidInteriorAddress - sect->addr;
- return true;
- }
- }
- }
- }
- break;
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
- return false;
-}
-
-
-bool ImageLoaderMachO::symbolRequiresCoalescing(const struct macho_nlist* symbol)
-{
- // if a define and weak ==> coalesced
- if ( ((symbol->n_type & N_TYPE) == N_SECT) && ((symbol->n_desc & N_WEAK_DEF) != 0) )
- return true;
- // if an undefine and not referencing a weak symbol ==> coalesced
- if ( ((symbol->n_type & N_TYPE) != N_SECT) && ((symbol->n_desc & N_REF_TO_WEAK) != 0) )
- return true;
-
- // regular symbol
- return false;
-}
-
-
-static void __attribute__((noreturn)) throwSymbolNotFound(const char* symbol, const char* referencedFrom, const char* expectedIn)
-{
- dyld::throwf("Symbol not found: %s\n Referenced from: %s\n Expected in: %s\n", symbol, referencedFrom, expectedIn);
-}
-
-uintptr_t ImageLoaderMachO::resolveUndefined(const LinkContext& context, const struct macho_nlist* undefinedSymbol, bool twoLevel, const ImageLoader** foundIn)
-{
- ++fgTotalBindSymbolsResolved;
- const char* symbolName = &fStrings[undefinedSymbol->n_un.n_strx];
-
-#if LINKEDIT_USAGE_DEBUG
- noteAccessedLinkEditAddress(undefinedSymbol);
- noteAccessedLinkEditAddress(symbolName);
-#endif
- if ( context.bindFlat || !twoLevel ) {
- // flat lookup
- if ( ((undefinedSymbol->n_type & N_PEXT) != 0) && ((undefinedSymbol->n_type & N_TYPE) == N_SECT) ) {
- // is a multi-module private_extern internal reference that the linker did not optimize away
- uintptr_t addr = this->getSymbolAddress(undefinedSymbol, this, context);
- *foundIn = this;
- return addr;
- }
- const Symbol* sym;
- if ( context.flatExportFinder(symbolName, &sym, foundIn) ) {
- if ( (*foundIn != this) && !(*foundIn)->neverUnload() )
- this->addDynamicReference(*foundIn);
- return (*foundIn)->getExportedSymbolAddress(sym, context, this);
- }
- // if a bundle is loaded privately the above will not find its exports
- if ( this->isBundle() && this->hasHiddenExports() ) {
- // look in self for needed symbol
- sym = this->findExportedSymbol(symbolName, NULL, false, foundIn);
- if ( sym != NULL )
- return (*foundIn)->getExportedSymbolAddress(sym, context, this);
- }
- if ( (undefinedSymbol->n_desc & N_WEAK_REF) != 0 ) {
- // definition can't be found anywhere
- // if reference is weak_import, then it is ok, just return 0
- return 0;
- }
- throwSymbolNotFound(symbolName, this->getPath(), "flat namespace");
- }
- else {
- // symbol requires searching images with coalesced symbols (not done during prebinding)
- if ( !context.prebinding && this->needsCoalescing() && symbolRequiresCoalescing(undefinedSymbol) ) {
- const Symbol* sym;
- if ( context.coalescedExportFinder(symbolName, &sym, foundIn) ) {
- if ( (*foundIn != this) && !(*foundIn)->neverUnload() )
- this->addDynamicReference(*foundIn);
- return (*foundIn)->getExportedSymbolAddress(sym, context, this);
- }
- //throwSymbolNotFound(symbolName, this->getPath(), "coalesced namespace");
- //dyld::log("dyld: coalesced symbol %s not found in any coalesced image, falling back to two-level lookup", symbolName);
- }
-
- // if this is a real definition (not an undefined symbol) there is no ordinal
- if ( (undefinedSymbol->n_type & N_TYPE) == N_SECT ) {
- // static linker should never generate this case, but if it does, do something sane
- uintptr_t addr = this->getSymbolAddress(undefinedSymbol, this, context);
- *foundIn = this;
- return addr;
- }
-
- // two level lookup
- void* hint = NULL;
- ImageLoader* target = NULL;
- uint8_t ord = GET_LIBRARY_ORDINAL(undefinedSymbol->n_desc);
- if ( ord == EXECUTABLE_ORDINAL ) {
- target = context.mainExecutable;
- }
- else if ( ord == SELF_LIBRARY_ORDINAL ) {
- target = this;
- }
- else if ( ord == DYNAMIC_LOOKUP_ORDINAL ) {
- // rnielsen: HACKHACK
- // flat lookup
- const Symbol* sym;
- if ( context.flatExportFinder(symbolName, &sym, foundIn) )
- return (*foundIn)->getExportedSymbolAddress(sym, context, this);
- // no image has exports this symbol
- // either report error or hope ZeroLink can just-in-time load an image
- context.undefinedHandler(symbolName);
- // try looking again
- if ( context.flatExportFinder(symbolName, &sym, foundIn) )
- return (*foundIn)->getExportedSymbolAddress(sym, context, this);
-
- throwSymbolNotFound(symbolName, this->getPath(), "dynamic lookup");
- }
- else if ( ord <= fLibrariesCount ) {
- DependentLibrary& libInfo = fLibraries[ord-1];
- target = libInfo.image;
- if ( (target == NULL) && (((undefinedSymbol->n_desc & N_WEAK_REF) != 0) || !libInfo.required) ) {
- // if target library not loaded and reference is weak or library is weak return 0
- return 0;
- }
- }
- else {
- dyld::throwf("bad mach-o binary, library ordinal (%u) too big (max %u) for symbol %s in %s",
- ord, fLibrariesCount, symbolName, this->getPath());
- }
-
- if ( target == NULL ) {
- //dyld::log("resolveUndefined(%s) in %s\n", symbolName, this->getPath());
- throw "symbol not found";
- }
-
- // interpret hint
- if ( fTwoLevelHints != NULL ) {
- uint32_t symIndex = undefinedSymbol - fSymbolTable;
- int32_t undefinedIndex = symIndex - fDynamicInfo->iundefsym;
- if ( (undefinedIndex >= 0) && ((uint32_t)undefinedIndex < fDynamicInfo->nundefsym) ) {
- const struct twolevel_hint* hints = (struct twolevel_hint*)(&fLinkEditBase[fTwoLevelHints->offset]);
- const struct twolevel_hint* theHint = &hints[undefinedIndex];
- hint = (void*)theHint;
- }
- }
-
- const Symbol* sym = target->findExportedSymbol(symbolName, hint, true, foundIn);
- if ( sym!= NULL ) {
- return (*foundIn)->getExportedSymbolAddress(sym, context, this);
- }
- else if ( (undefinedSymbol->n_type & N_PEXT) != 0 ) {
- // don't know why the static linker did not eliminate the internal reference to a private extern definition
- *foundIn = this;
- return this->getSymbolAddress(undefinedSymbol, this, context);
- }
- else if ( (undefinedSymbol->n_desc & N_WEAK_REF) != 0 ) {
- // if definition not found and reference is weak return 0
- return 0;
- }
-
- // nowhere to be found
- throwSymbolNotFound(symbolName, this->getPath(), target->getPath());
- }
-}
-
-// returns if 'addr' is within the address range of section 'sectionIndex'
-// fSlide is not used. 'addr' is assumed to be a prebound address in this image
-bool ImageLoaderMachO::isAddrInSection(uintptr_t addr, uint8_t sectionIndex)
-{
- uint8_t currentSectionIndex = 1;
- const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
- const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
- const struct load_command* cmd = cmds;
- for (unsigned long i = 0; i < cmd_count; ++i) {
- if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
- const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
- if ( (currentSectionIndex <= sectionIndex) && (sectionIndex < currentSectionIndex+seg->nsects) ) {
- // 'sectionIndex' is in this segment, get section info
- const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
- const struct macho_section* const section = §ionsStart[sectionIndex-currentSectionIndex];
- return ( (section->addr <= addr) && (addr < section->addr+section->size) );
- }
- else {
- // 'sectionIndex' not in this segment, skip to next segment
- currentSectionIndex += seg->nsects;
- }
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
-
- return false;
-}
-
-void ImageLoaderMachO::doBindExternalRelocations(const LinkContext& context, bool onlyCoalescedSymbols)
-{
- const uintptr_t relocBase = this->getRelocBase();
- const bool twoLevel = this->usesTwoLevelNameSpace();
- const bool prebound = this->isPrebindable();
-
-#if TEXT_RELOC_SUPPORT
- // if there are __TEXT fixups, temporarily make __TEXT writable
- if ( fTextSegmentWithFixups != NULL )
- fTextSegmentWithFixups->tempWritable(context, this);
-#endif
- // cache last lookup
- const struct macho_nlist* lastUndefinedSymbol = NULL;
- uintptr_t symbolAddr = 0;
- const ImageLoader* image = NULL;
-
- // loop through all external relocation records and bind each
- const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->extreloff]);
- const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nextrel];
- for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
- if (reloc->r_length == RELOC_SIZE) {
- switch(reloc->r_type) {
- case POINTER_RELOC:
- {
- const struct macho_nlist* undefinedSymbol = &fSymbolTable[reloc->r_symbolnum];
- // if only processing coalesced symbols and this one does not require coalesceing, skip to next
- if ( onlyCoalescedSymbols && !symbolRequiresCoalescing(undefinedSymbol) )
- continue;
- uintptr_t* location = ((uintptr_t*)(reloc->r_address + relocBase));
- uintptr_t value = *location;
- bool symbolAddrCached = true;
- #if __i386__
- if ( reloc->r_pcrel ) {
- value += (uintptr_t)location + 4 - fSlide;
- }
- #endif
- if ( prebound ) {
- // we are doing relocations, so prebinding was not usable
- // in a prebound executable, the n_value field of an undefined symbol is set to the address where the symbol was found when prebound
- // so, subtracting that gives the initial displacement which we need to add to the newly found symbol address
- // if mach-o relocation structs had an "addend" field this complication would not be necessary.
- if ( ((undefinedSymbol->n_type & N_TYPE) == N_SECT) && ((undefinedSymbol->n_desc & N_WEAK_DEF) != 0) ) {
- // weak symbols need special casing, since *location may have been prebound to a definition in another image.
- // If *location is currently prebound to somewhere in the same section as the weak definition, we assume
- // that we can subtract off the weak symbol address to get the addend.
- // If prebound elsewhere, we've lost the addend and have to assume it is zero.
- // The prebinding to elsewhere only happens with 10.4+ update_prebinding which only operates on a small set of Apple dylibs
- if ( (value == undefinedSymbol->n_value) || this->isAddrInSection(value, undefinedSymbol->n_sect) )
- value -= undefinedSymbol->n_value;
- else
- value = 0;
- }
- else {
- // is undefined or non-weak symbol, so do subtraction to get addend
- value -= undefinedSymbol->n_value;
- }
- }
- // if undefinedSymbol is same as last time, then symbolAddr and image will resolve to the same too
- if ( undefinedSymbol != lastUndefinedSymbol ) {
- symbolAddr = this->resolveUndefined(context, undefinedSymbol, twoLevel, &image);
- lastUndefinedSymbol = undefinedSymbol;
- symbolAddrCached = false;
- }
- if ( context.verboseBind ) {
- const char *path = NULL;
- if ( image != NULL ) {
- path = image->getShortName();
- }
- const char* cachedString = "(cached)";
- if ( !symbolAddrCached )
- cachedString = "";
- if ( value == 0 ) {
- dyld::log("dyld: bind: %s:0x%08lX = %s:%s, *0x%08lX = 0x%08lX%s\n",
- this->getShortName(), (uintptr_t)location,
- path, &fStrings[undefinedSymbol->n_un.n_strx], (uintptr_t)location, symbolAddr, cachedString);
- }
- else {
- dyld::log("dyld: bind: %s:0x%08lX = %s:%s, *0x%08lX = 0x%08lX%s + %ld\n",
- this->getShortName(), (uintptr_t)location,
- path, &fStrings[undefinedSymbol->n_un.n_strx], (uintptr_t)location, symbolAddr, cachedString, value);
- }
- }
- value += symbolAddr;
- #if __i386__
- if ( reloc->r_pcrel ) {
- *location = value - ((uintptr_t)location + 4);
- }
- else {
- // don't dirty page if prebound value was correct
- if ( !prebound || (*location != value) )
- *location = value;
- }
- #else
- // don't dirty page if prebound value was correct
- if ( !prebound || (*location != value) )
- *location = value;
- #endif
- // update stats
- ++fgTotalBindFixups;
- }
- break;
- default:
- throw "unknown external relocation type";
- }
- }
- else {
- throw "bad external relocation length";
- }
- }
-
-#if TEXT_RELOC_SUPPORT
- // if there were __TEXT fixups, restore write protection
- if ( fTextSegmentWithFixups != NULL ) {
- fTextSegmentWithFixups->setPermissions(context, this);
- sys_icache_invalidate((void*)fTextSegmentWithFixups->getActualLoadAddress(this), fTextSegmentWithFixups->getSize());
- }
-#endif
-}
-
-const mach_header* ImageLoaderMachO::machHeader() const
-{
- return (mach_header*)fMachOData;
-}
-
-uintptr_t ImageLoaderMachO::getSlide() const
-{
- return fSlide;
-}
-
-// hmm. maybe this should be up in ImageLoader??
-const void* ImageLoaderMachO::getEnd() const
-{
- uintptr_t lastAddress = 0;
- for (ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
- Segment* seg = *it;
- uintptr_t segEnd = seg->getActualLoadAddress(this) + seg->getSize();
- if ( segEnd > lastAddress )
- lastAddress = segEnd;
- }
- return (const void*)lastAddress;
-}
-
-uintptr_t ImageLoaderMachO::bindIndirectSymbol(uintptr_t* ptrToBind, const struct macho_section* sect, const char* symbolName, uintptr_t targetAddr, const ImageLoader* targetImage, const LinkContext& context)
-{
- if ( context.verboseBind ) {
- const char* path = NULL;
- if ( targetImage != NULL )
- path = targetImage->getShortName();
- dyld::log("dyld: bind: %s:%s$%s = %s:%s, *0x%08lx = 0x%08lx\n",
- this->getShortName(), symbolName, (((sect->flags & SECTION_TYPE)==S_NON_LAZY_SYMBOL_POINTERS) ? "non_lazy_ptr" : "lazy_ptr"),
- path, symbolName, (uintptr_t)ptrToBind, targetAddr);
- }
- if ( context.bindingHandler != NULL ) {
- const char* path = NULL;
- if ( targetImage != NULL )
- path = targetImage->getShortName();
- targetAddr = (uintptr_t)context.bindingHandler(path, symbolName, (void *)targetAddr);
- }
-#if __i386__
- // i386 has special self-modifying stubs that change from "CALL rel32" to "JMP rel32"
- if ( ((sect->flags & SECTION_TYPE) == S_SYMBOL_STUBS) && ((sect->flags & S_ATTR_SELF_MODIFYING_CODE) != 0) && (sect->reserved2 == 5) ) {
- uint32_t rel32 = targetAddr - (((uint32_t)ptrToBind)+5);
- // re-write instruction in a thread-safe manner
- // use 8-byte compare-and-swap to alter 5-byte jump table entries
- // loop is required in case the extra three bytes that cover the next entry are altered by another thread
- bool done = false;
- while ( !done ) {
- volatile int64_t* jumpPtr = (int64_t*)ptrToBind;
- int pad = 0;
- // By default the three extra bytes swapped follow the 5-byte JMP.
- // But, if the 5-byte jump is up against the end of the __IMPORT segment
- // We don't want to access bytes off the end of the segment, so we shift
- // the extra bytes to precede the 5-byte JMP.
- if ( (((uint32_t)ptrToBind + 8) & 0x00000FFC) == 0x00000000 ) {
- jumpPtr = (int64_t*)((uint32_t)ptrToBind - 3);
- pad = 3;
- }
- int64_t oldEntry = *jumpPtr;
- union {
- int64_t int64;
- uint8_t bytes[8];
- } newEntry;
- newEntry.int64 = oldEntry;
- newEntry.bytes[pad+0] = 0xE9; // JMP rel32
- newEntry.bytes[pad+1] = rel32 & 0xFF;
- newEntry.bytes[pad+2] = (rel32 >> 8) & 0xFF;
- newEntry.bytes[pad+3] = (rel32 >> 16) & 0xFF;
- newEntry.bytes[pad+4] = (rel32 >> 24) & 0xFF;
- done = OSAtomicCompareAndSwap64Barrier(oldEntry, newEntry.int64, (int64_t*)jumpPtr);
- }
- }
- else
-#endif
- *ptrToBind = targetAddr;
- return targetAddr;
-}
-
-
-uintptr_t ImageLoaderMachO::doBindLazySymbol(uintptr_t* lazyPointer, const LinkContext& context)
-{
- // scan for all non-lazy-pointer sections
- const bool twoLevel = this->usesTwoLevelNameSpace();
- const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
- const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
- const struct load_command* cmd = cmds;
- const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
- 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;
- 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;
- uint32_t symbolIndex = INDIRECT_SYMBOL_LOCAL;
- if ( type == S_LAZY_SYMBOL_POINTERS ) {
- const uint32_t pointerCount = sect->size / sizeof(uintptr_t);
- uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + fSlide);
- if ( (lazyPointer >= symbolPointers) && (lazyPointer < &symbolPointers[pointerCount]) ) {
- const uint32_t indirectTableOffset = sect->reserved1;
- const uint32_t lazyIndex = lazyPointer - symbolPointers;
- symbolIndex = indirectTable[indirectTableOffset + lazyIndex];
- }
- }
- #if __i386__
- else if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
- // 5 bytes stubs on i386 are new "fast stubs"
- uint8_t* const jmpTableBase = (uint8_t*)(sect->addr + fSlide);
- uint8_t* const jmpTableEnd = jmpTableBase + sect->size;
- // initial CALL instruction in jump table leaves pointer to next entry, so back up
- uint8_t* const jmpTableEntryToPatch = ((uint8_t*)lazyPointer) - 5;
- lazyPointer = (uintptr_t*)jmpTableEntryToPatch;
- if ( (jmpTableEntryToPatch >= jmpTableBase) && (jmpTableEntryToPatch < jmpTableEnd) ) {
- const uint32_t indirectTableOffset = sect->reserved1;
- const uint32_t entryIndex = (jmpTableEntryToPatch - jmpTableBase)/5;
- symbolIndex = indirectTable[indirectTableOffset + entryIndex];
- }
- }
- #endif
- if ( symbolIndex != INDIRECT_SYMBOL_ABS && symbolIndex != INDIRECT_SYMBOL_LOCAL ) {
- const char* symbolName = &fStrings[fSymbolTable[symbolIndex].n_un.n_strx];
- const ImageLoader* image = NULL;
- uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], twoLevel, &image);
- #if __i386__
- this->makeImportSegmentWritable(context);
- #endif
- symbolAddr = this->bindIndirectSymbol(lazyPointer, sect, symbolName, symbolAddr, image, context);
- ++fgTotalLazyBindFixups;
- #if __i386__
- this->makeImportSegmentReadOnly(context);
- #endif
- return symbolAddr;
+ return true;
}
}
}
}
cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
- dyld::throwf("lazy pointer not found at address %p in image %s", lazyPointer, this->getPath());
-}
-
-
-#if __i386__
-//
-// For security the __IMPORT segments in the shared cache are normally not writable.
-// Any image can also be linked with -read_only_stubs to make their __IMPORT segments normally not writable.
-// For these images, dyld must change the page protection before updating them.
-// The spin lock is required because lazy symbol binding is done without taking the global dyld lock.
-// It keeps only one __IMPORT segment writable at a time.
-// Pre-main(), the shared cache __IMPORT segments are always writable, so we don't need to change the protection.
-//
-void ImageLoaderMachO::makeImportSegmentWritable(const LinkContext& context)
-{
- if ( fReadOnlyImportSegment != NULL ) {
- if ( fInSharedCache ) {
- if ( context.startedInitializingMainExecutable ) {
- _spin_lock(&fgReadOnlyImportSpinLock);
- context.makeSharedCacheImportSegmentsWritable(true);
- }
- }
- else {
- _spin_lock(&fgReadOnlyImportSpinLock);
- fReadOnlyImportSegment->tempWritable(context, this);
- }
- }
+ *start = NULL;
+ *length = 0;
+ return false;
}
-void ImageLoaderMachO::makeImportSegmentReadOnly(const LinkContext& context)
+void ImageLoaderMachO::getUnwindInfo(dyld_unwind_sections* info)
{
- if ( fReadOnlyImportSegment != NULL ) {
- if ( fInSharedCache ) {
- if ( context.startedInitializingMainExecutable ) {
- context.makeSharedCacheImportSegmentsWritable(false);
- _spin_unlock(&fgReadOnlyImportSpinLock);
- }
- }
- else {
- fReadOnlyImportSegment->setPermissions(context, this);
- _spin_unlock(&fgReadOnlyImportSpinLock);
- }
+ info->mh = this->machHeader();
+ info->dwarf_section = 0;
+ info->dwarf_section_length = 0;
+ info->compact_unwind_section = 0;
+ info->compact_unwind_section_length = 0;
+ if ( fEHFrameSectionOffset != 0 ) {
+ const macho_section* sect = (macho_section*)&fMachOData[fEHFrameSectionOffset];
+ info->dwarf_section = (void*)(sect->addr + fSlide);
+ info->dwarf_section_length = sect->size;
+ }
+ if ( fUnwindInfoSectionOffset != 0 ) {
+ const macho_section* sect = (macho_section*)&fMachOData[fUnwindInfoSectionOffset];
+ info->compact_unwind_section = (void*)(sect->addr + fSlide);
+ info->compact_unwind_section_length = sect->size;
}
}
-#endif
-void ImageLoaderMachO::doBindIndirectSymbolPointers(const LinkContext& context, bool bindNonLazys, bool bindLazys, bool onlyCoalescedSymbols)
+
+bool ImageLoaderMachO::findSection(const void* imageInterior, const char** segmentName, const char** sectionName, size_t* sectionOffset)
{
-#if __i386__
- this->makeImportSegmentWritable(context);
-#endif
- // scan for all non-lazy-pointer sections
- const bool twoLevel = this->usesTwoLevelNameSpace();
const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
const struct load_command* cmd = cmds;
- const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
+ const uintptr_t unslidInteriorAddress = (uintptr_t)imageInterior - this->getSlide();
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;
- 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;
- uint32_t elementSize = sizeof(uintptr_t);
- uint32_t elementCount = sect->size / elementSize;
- if ( type == S_NON_LAZY_SYMBOL_POINTERS ) {
- if ( ! bindNonLazys )
- continue;
- }
- else if ( type == S_LAZY_SYMBOL_POINTERS ) {
- // process each symbol pointer in this section
- fgTotalPossibleLazyBindFixups += elementCount;
- if ( ! bindLazys )
- continue;
- }
- #if __i386__
- else if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
- // process each jmp entry in this section
- elementCount = sect->size / 5;
- elementSize = 5;
- fgTotalPossibleLazyBindFixups += elementCount;
- if ( ! bindLazys )
- continue;
- }
- #endif
- else {
- continue;
- }
- const uint32_t indirectTableOffset = sect->reserved1;
- uint8_t* ptrToBind = (uint8_t*)(sect->addr + fSlide);
- for (uint32_t j=0; j < elementCount; ++j, ptrToBind += elementSize) {
- #if LINKEDIT_USAGE_DEBUG
- noteAccessedLinkEditAddress(&indirectTable[indirectTableOffset + j]);
- #endif
- uint32_t symbolIndex = indirectTable[indirectTableOffset + j];
- if ( symbolIndex == INDIRECT_SYMBOL_LOCAL) {
- *((uintptr_t*)ptrToBind) += this->fSlide;
- }
- else if ( symbolIndex == INDIRECT_SYMBOL_ABS) {
- // do nothing since already has absolute address
- }
- else {
- const struct macho_nlist* sym = &fSymbolTable[symbolIndex];
- if ( symbolIndex == 0 ) {
- // This could be rdar://problem/3534709
- if ( ((const macho_header*)fMachOData)->filetype == MH_EXECUTE ) {
- static bool alreadyWarned = false;
- if ( (sym->n_type & N_TYPE) != N_UNDF ) {
- // The indirect table parallels the (non)lazy pointer sections. For
- // instance, to find info about the fifth lazy pointer you look at the
- // fifth entry in the indirect table. (try otool -Iv on a file).
- // The entry in the indirect table contains an index into the symbol table.
-
- // The bug in ld caused the entry in the indirect table to be zero
- // (instead of a magic value that means a local symbol). So, if the
- // symbolIndex == 0, we may be encountering the bug, or 0 may be a valid
- // symbol table index. The check I put in place is to see if the zero'th
- // symbol table entry is an import entry (usually it is a local symbol
- // definition).
- if ( context.verboseWarnings && !alreadyWarned ) {
- dyld::log("dyld: malformed executable '%s', skipping indirect symbol to %s\n",
- this->getPath(), &fStrings[sym->n_un.n_strx]);
- alreadyWarned = true;
- }
- continue;
- }
- }
- }
- const ImageLoader* image = NULL;
- // if only processing coalesced symbols and this one does not require coalesceing, skip to next
- if ( onlyCoalescedSymbols && !symbolRequiresCoalescing(sym) )
- continue;
- uintptr_t symbolAddr;
- symbolAddr = resolveUndefined(context, sym, twoLevel, &image);
-
- // update pointer
- symbolAddr = this->bindIndirectSymbol((uintptr_t*)ptrToBind, sect, &fStrings[sym->n_un.n_strx], symbolAddr, image, context);
- // update stats
- ++fgTotalBindFixups;
+ if ( (unslidInteriorAddress >= seg->vmaddr) && (unslidInteriorAddress < (seg->vmaddr+seg->vmsize)) ) {
+ 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) {
+ if ((sect->addr <= unslidInteriorAddress) && (unslidInteriorAddress < (sect->addr+sect->size))) {
+ if ( segmentName != NULL )
+ *segmentName = sect->segname;
+ if ( sectionName != NULL )
+ *sectionName = sect->sectname;
+ if ( sectionOffset != NULL )
+ *sectionOffset = unslidInteriorAddress - sect->addr;
+ return true;
}
}
}
}
cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
-#if __i386__
- this->makeImportSegmentReadOnly(context);
+ return false;
+}
+
+
+void __attribute__((noreturn)) ImageLoaderMachO::throwSymbolNotFound(const LinkContext& context, const char* symbol,
+ const char* referencedFrom, const char* fromVersMismatch,
+ const char* expectedIn)
+{
+ // record values for possible use by CrashReporter or Finder
+ (*context.setErrorStrings)(dyld_error_kind_symbol_missing, referencedFrom, expectedIn, symbol);
+ dyld::throwf("Symbol not found: %s\n Referenced from: %s%s\n Expected in: %s\n",
+ symbol, referencedFrom, fromVersMismatch, expectedIn);
+}
+
+const mach_header* ImageLoaderMachO::machHeader() const
+{
+ return (mach_header*)fMachOData;
+}
+
+uintptr_t ImageLoaderMachO::getSlide() const
+{
+ return fSlide;
+}
+
+// hmm. maybe this should be up in ImageLoader??
+const void* ImageLoaderMachO::getEnd() const
+{
+ uintptr_t lastAddress = 0;
+ for(unsigned int i=0; i < fSegmentsCount; ++i) {
+ uintptr_t segEnd = segActualEndAddress(i);
+ if ( strcmp(segName(i), "__UNIXSTACK") != 0 ) {
+ if ( segEnd > lastAddress )
+ lastAddress = segEnd;
+ }
+ }
+ return (const void*)lastAddress;
+}
+
+
+uintptr_t ImageLoaderMachO::bindLocation(const LinkContext& context, uintptr_t location, uintptr_t value,
+ const ImageLoader* targetImage, uint8_t type, const char* symbolName,
+ intptr_t addend, const char* msg)
+{
+ // log
+ if ( context.verboseBind ) {
+ if ( addend != 0 )
+ dyld::log("dyld: %sbind: %s:0x%08lX = %s:%s, *0x%08lX = 0x%08lX + %ld\n",
+ msg, this->getShortName(), (uintptr_t)location,
+ ((targetImage != NULL) ? targetImage->getShortName() : "<weak_import-missing>"),
+ symbolName, (uintptr_t)location, value, addend);
+ else
+ dyld::log("dyld: %sbind: %s:0x%08lX = %s:%s, *0x%08lX = 0x%08lX\n",
+ msg, this->getShortName(), (uintptr_t)location,
+ ((targetImage != NULL) ? targetImage->getShortName() : "<weak>import-missing>"),
+ symbolName, (uintptr_t)location, value);
+ }
+#if LOG_BINDINGS
+// dyld::logBindings("%s: %s\n", targetImage->getShortName(), symbolName);
#endif
+
+ // do actual update
+ uintptr_t* locationToFix = (uintptr_t*)location;
+ uint32_t* loc32;
+ uintptr_t newValue = value+addend;
+ uint32_t value32;
+ switch (type) {
+ case BIND_TYPE_POINTER:
+ // test first so we don't needless dirty pages
+ if ( *locationToFix != newValue )
+ *locationToFix = newValue;
+ break;
+ case BIND_TYPE_TEXT_ABSOLUTE32:
+ loc32 = (uint32_t*)locationToFix;
+ value32 = (uint32_t)newValue;
+ if ( *loc32 != value32 )
+ *loc32 = value32;
+ break;
+ case BIND_TYPE_TEXT_PCREL32:
+ loc32 = (uint32_t*)locationToFix;
+ value32 = (uint32_t)(newValue - (((uintptr_t)locationToFix) + 4));
+ if ( *loc32 != value32 )
+ *loc32 = value32;
+ break;
+ default:
+ dyld::throwf("bad bind type %d", type);
+ }
+
+ // update statistics
+ ++fgTotalBindFixups;
+
+ return newValue;
}
+
+
+
+
#if SUPPORT_OLD_CRT_INITIALIZATION
// first 16 bytes of "start" in crt1.o
-#if __ppc__
- static uint32_t sStandardEntryPointInstructions[4] = { 0x7c3a0b78, 0x3821fffc, 0x54210034, 0x38000000 };
-#elif __i386__
+#if __i386__
static uint8_t sStandardEntryPointInstructions[16] = { 0x6a, 0x00, 0x89, 0xe5, 0x83, 0xe4, 0xf0, 0x83, 0xec, 0x10, 0x8b, 0x5d, 0x04, 0x89, 0x5c, 0x24 };
#endif
#endif
struct DATAdyld {
- void* dyldLazyBinder; // filled in at launch by dyld to point into dyld to &stub_binding_helper_interface
+ void* dyldLazyBinder; // filled in at launch by dyld to point into dyld to &stub_binding_helper
void* dyldFuncLookup; // filled in at launch by dyld to point into dyld to &_dyld_func_lookup
// the following only exist in main executables built for 10.5 or later
ProgramVars vars;
// These are defined in dyldStartup.s
extern "C" void stub_binding_helper();
-extern "C" bool dyld_func_lookup(const char* name, uintptr_t* address);
-extern "C" void fast_stub_binding_helper_interface();
void ImageLoaderMachO::setupLazyPointerHandler(const LinkContext& context)
const uint32_t cmd_count = mh->ncmds;
const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
const struct load_command* cmd;
- // set up __dyld section
- // optimizations:
- // 1) do nothing if image is in dyld shared cache and dyld loaded at same address as when cache built
- // 2) first read __dyld value, if already correct don't write, this prevents dirtying a page
- if ( !fInSharedCache || !context.dyldLoadedAtSameAddressNeededBySharedCache ) {
+ // There used to be some optimizations to skip this section scan, but we need to handle the
+ // __dyld section in libdyld.dylib, so everything needs to be scanned for now.
+ // <rdar://problem/10910062> CrashTracer: 1,295 crashes in bash at bash: getenv
+ if ( true ) {
cmd = cmds;
for (uint32_t i = 0; i < cmd_count; ++i) {
if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
- if ( strcmp(seg->segname, "__DATA") == 0 ) {
+ if ( strncmp(seg->segname, "__DATA", 6) == 0 ) {
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) {
if ( strcmp(sect->sectname, "__dyld" ) == 0 ) {
struct DATAdyld* dd = (struct DATAdyld*)(sect->addr + fSlide);
+ #if !__arm64__ && !__ARM_ARCH_7K__
if ( sect->size > offsetof(DATAdyld, dyldLazyBinder) ) {
if ( dd->dyldLazyBinder != (void*)&stub_binding_helper )
dd->dyldLazyBinder = (void*)&stub_binding_helper;
}
+ #endif // !__arm64__
if ( sect->size > offsetof(DATAdyld, dyldFuncLookup) ) {
- if ( dd->dyldFuncLookup != (void*)&dyld_func_lookup )
- dd->dyldFuncLookup = (void*)&dyld_func_lookup;
+ if ( dd->dyldFuncLookup != (void*)&_dyld_func_lookup )
+ dd->dyldFuncLookup = (void*)&_dyld_func_lookup;
}
if ( mh->filetype == MH_EXECUTE ) {
// there are two ways to get the program variables
#endif
}
}
- }
- }
- }
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
- }
-#if __i386__
- if ( ! this->usablePrebinding(context) ) {
- // reset all "fast" stubs
- this->makeImportSegmentWritable(context);
- 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;
- 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_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
- // reset each jmp entry in this section
- const uint32_t indirectTableOffset = sect->reserved1;
- const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
- uint8_t* start = (uint8_t*)(sect->addr + this->fSlide);
- uint8_t* end = start + sect->size;
- uintptr_t dyldHandler = (uintptr_t)&fast_stub_binding_helper_interface;
- uint32_t entryIndex = 0;
- for (uint8_t* entry = start; entry < end; entry += 5, ++entryIndex) {
- bool installLazyHandler = true;
- // jump table entries that cross a (64-byte) cache line boundary have the potential to cause crashes
- // if the instruction is updated by one thread while being executed by another
- if ( ((uint32_t)entry & 0xFFFFFFC0) != ((uint32_t)entry+4 & 0xFFFFFFC0) ) {
- // need to bind this now to avoid a potential problem if bound lazily
- uint32_t symbolIndex = indirectTable[indirectTableOffset + entryIndex];
- // the latest linker marks 64-byte crossing stubs with INDIRECT_SYMBOL_ABS so they are not used
- if ( symbolIndex != INDIRECT_SYMBOL_ABS ) {
- const char* symbolName = &fStrings[fSymbolTable[symbolIndex].n_un.n_strx];
- const ImageLoader* image = NULL;
- try {
- uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], this->usesTwoLevelNameSpace(), &image);
- symbolAddr = this->bindIndirectSymbol((uintptr_t*)entry, sect, symbolName, symbolAddr, image, context);
- ++fgTotalBindFixups;
- uint32_t rel32 = symbolAddr - (((uint32_t)entry)+5);
- entry[0] = 0xE9; // JMP rel32
- entry[1] = rel32 & 0xFF;
- entry[2] = (rel32 >> 8) & 0xFF;
- entry[3] = (rel32 >> 16) & 0xFF;
- entry[4] = (rel32 >> 24) & 0xFF;
- installLazyHandler = false;
- }
- catch (const char* msg) {
- // ignore errors when binding symbols early
- // maybe the function is never called, and therefore erroring out now would be a regression
- }
+ else if ( mh->filetype == MH_DYLIB ) {
+ const char* installPath = this->getInstallPath();
+ if ( (installPath != NULL) && (strncmp(installPath, "/usr/lib/", 9) == 0) ) {
+ if ( sect->size > offsetof(DATAdyld, vars) ) {
+ // use ProgramVars from libdyld.dylib but tweak mh field to correct value
+ dd->vars.mh = context.mainExecutable->machHeader();
+ context.setNewProgramVars(dd->vars);
}
}
- if ( installLazyHandler ) {
- uint32_t rel32 = dyldHandler - (((uint32_t)entry)+5);
- entry[0] = 0xE8; // CALL rel32
- entry[1] = rel32 & 0xFF;
- entry[2] = (rel32 >> 8) & 0xFF;
- entry[3] = (rel32 >> 16) & 0xFF;
- entry[4] = (rel32 >> 24) & 0xFF;
- }
}
}
+ else if ( (strcmp(sect->sectname, "__program_vars" ) == 0) && (mh->filetype == MH_EXECUTE) ) {
+ // this is a Mac OS X 10.6 or later main executable
+ struct ProgramVars* pv = (struct ProgramVars*)(sect->addr + fSlide);
+ context.setNewProgramVars(*pv);
+ }
}
}
}
cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
- this->makeImportSegmentReadOnly(context);
}
-#endif
}
vars.mh = (macho_header*)fMachOData;
// lookup _NXArgc
- sym = this->findExportedSymbol("_NXArgc", NULL, false, NULL);
+ sym = this->findExportedSymbol("_NXArgc", false, NULL);
if ( sym != NULL )
- vars.NXArgcPtr = (int*)this->getExportedSymbolAddress(sym, context, this);
+ vars.NXArgcPtr = (int*)this->getExportedSymbolAddress(sym, context, this, false);
// lookup _NXArgv
- sym = this->findExportedSymbol("_NXArgv", NULL, false, NULL);
+ sym = this->findExportedSymbol("_NXArgv", false, NULL);
if ( sym != NULL )
- vars.NXArgvPtr = (const char***)this->getExportedSymbolAddress(sym, context, this);
+ vars.NXArgvPtr = (const char***)this->getExportedSymbolAddress(sym, context, this, false);
// lookup _environ
- sym = this->findExportedSymbol("_environ", NULL, false, NULL);
+ sym = this->findExportedSymbol("_environ", false, NULL);
if ( sym != NULL )
- vars.environPtr = (const char***)this->getExportedSymbolAddress(sym, context, this);
+ vars.environPtr = (const char***)this->getExportedSymbolAddress(sym, context, this, false);
// lookup __progname
- sym = this->findExportedSymbol("___progname", NULL, false, NULL);
+ sym = this->findExportedSymbol("___progname", false, NULL);
if ( sym != NULL )
- vars.__prognamePtr = (const char**)this->getExportedSymbolAddress(sym, context, this);
+ vars.__prognamePtr = (const char**)this->getExportedSymbolAddress(sym, context, this, false);
context.setNewProgramVars(vars);
}
bool ImageLoaderMachO::usablePrebinding(const LinkContext& context) const
{
// if prebound and loaded at prebound address, and all libraries are same as when this was prebound, then no need to bind
- if ( (this->isPrebindable() || fInSharedCache)
- && (this->getSlide() == 0)
+ if ( ((this->isPrebindable() && (this->getSlide() == 0)) || fInSharedCache)
&& this->usesTwoLevelNameSpace()
&& this->allDependentLibrariesAsWhenPreBound() ) {
// allow environment variables to disable prebinding
return false;
}
-void ImageLoaderMachO::doBindJustLazies(const LinkContext& context)
-{
- // some API called requested that all lazy pointers in this image be force bound
- this->doBindIndirectSymbolPointers(context, false, true, false);
-}
-
-void ImageLoaderMachO::doBind(const LinkContext& context, bool forceLazysBound)
-{
- // set dyld entry points in image
- this->setupLazyPointerHandler(context);
-
- // if prebound and loaded at prebound address, and all libraries are same as when this was prebound, then no need to bind
- // note: flat-namespace binaries need to have imports rebound (even if correctly prebound)
- if ( this->usablePrebinding(context) ) {
- // if image has coalesced symbols, then these need to be rebound, unless this is the only image with weak symbols
- if ( this->needsCoalescing() && (fgCountOfImagesWithWeakExports > 1) ) {
- this->doBindExternalRelocations(context, true);
- this->doBindIndirectSymbolPointers(context, true, true, true);
- }
- else {
- ++fgImagesRequiringNoFixups;
- }
-
- // skip binding because prebound and prebinding not disabled
- return;
- }
-
- // values bound by name are stored two different ways in mach-o:
-
- // 1) external relocations are used for data initialized to external symbols
- this->doBindExternalRelocations(context, false);
-
- // 2) "indirect symbols" are used for code references to external symbols
- // if this image is in the shared cache, there is noway to reset the lazy pointers, so bind them now
- this->doBindIndirectSymbolPointers(context, true, forceLazysBound || fInSharedCache, false);
-}
-
-void ImageLoaderMachO::doUpdateMappingPermissions(const LinkContext& context)
-{
-#if __i386__
- if ( (fReadOnlyImportSegment != NULL) && !fInSharedCache )
- fReadOnlyImportSegment->setPermissions(context, this);
-#endif
-}
void ImageLoaderMachO::doImageInit(const LinkContext& context)
{
const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
const struct load_command* cmd = cmds;
- for (unsigned long i = 0; i < cmd_count; ++i) {
+ for (uint32_t i = 0; i < cmd_count; ++i) {
switch (cmd->cmd) {
case LC_ROUTINES_COMMAND:
Initializer func = (Initializer)(((struct macho_routines_command*)cmd)->init_address + fSlide);
+ // <rdar://problem/8543820&9228031> verify initializers are in image
+ if ( ! this->containsAddress((void*)func) ) {
+ dyld::throwf("initializer function %p not in mapped image for %s\n", func, this->getPath());
+ }
if ( context.verboseInit )
- dyld::log("dyld: calling -init function 0x%p in %s\n", func, this->getPath());
+ dyld::log("dyld: calling -init function %p in %s\n", func, this->getPath());
func(context.argc, context.argv, context.envp, context.apple, &context.programVars);
break;
}
const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
const struct load_command* cmd = cmds;
- for (unsigned long i = 0; i < cmd_count; ++i) {
+ for (uint32_t i = 0; i < cmd_count; ++i) {
if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
const uint8_t type = sect->flags & SECTION_TYPE;
if ( type == S_MOD_INIT_FUNC_POINTERS ) {
Initializer* inits = (Initializer*)(sect->addr + fSlide);
- const uint32_t count = sect->size / sizeof(uintptr_t);
- for (uint32_t i=0; i < count; ++i) {
+ const size_t count = sect->size / sizeof(uintptr_t);
+ for (size_t i=0; i < count; ++i) {
Initializer func = inits[i];
+ // <rdar://problem/8543820&9228031> verify initializers are in image
+ if ( ! this->containsAddress((void*)func) ) {
+ dyld::throwf("initializer function %p not in mapped image for %s\n", func, this->getPath());
+ }
if ( context.verboseInit )
dyld::log("dyld: calling initializer function %p in %s\n", func, this->getPath());
func(context.argc, context.argv, context.envp, context.apple, &context.programVars);
}
}
}
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
}
}
+
+
void ImageLoaderMachO::doGetDOFSections(const LinkContext& context, std::vector<ImageLoader::DOFInfo>& dofs)
{
if ( fHasDOFSections ) {
}
-void ImageLoaderMachO::doInitialization(const LinkContext& context)
+bool ImageLoaderMachO::doInitialization(const LinkContext& context)
{
+ CRSetCrashLogMessage2(this->getPath());
+
// mach-o has -init and static initializers
doImageInit(context);
doModInitFunctions(context);
+
+ CRSetCrashLogMessage2(NULL);
+
+ return (fHasDashInit || fHasInitializers);
}
bool ImageLoaderMachO::needsInitialization()
return fHasTerminators;
}
-#if IMAGE_NOTIFY_SUPPORT
-bool ImageLoaderMachO::hasImageNotification()
-{
- return fHasImageNotifySection;
-}
-#endif
void ImageLoaderMachO::doTermination(const LinkContext& context)
{
const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
const struct load_command* cmd = cmds;
- for (unsigned long i = 0; i < cmd_count; ++i) {
+ for (uint32_t i = 0; i < cmd_count; ++i) {
if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
const uint8_t type = sect->flags & SECTION_TYPE;
if ( type == S_MOD_TERM_FUNC_POINTERS ) {
Terminator* terms = (Terminator*)(sect->addr + fSlide);
- const uint32_t count = sect->size / sizeof(uintptr_t);
- for (uint32_t i=count; i > 0; --i) {
+ const size_t count = sect->size / sizeof(uintptr_t);
+ for (size_t i=count; i > 0; --i) {
Terminator func = terms[i-1];
+ // <rdar://problem/8543820&9228031> verify terminators are in image
+ if ( ! this->containsAddress((void*)func) ) {
+ dyld::throwf("termination function %p not in mapped image for %s\n", func, this->getPath());
+ }
if ( context.verboseInit )
- dyld::log("dyld: calling terminaton function %p in %s\n", func, this->getPath());
+ dyld::log("dyld: calling termination function %p in %s\n", func, this->getPath());
func();
}
}
}
}
-#if IMAGE_NOTIFY_SUPPORT
-void ImageLoaderMachO::doNotification(enum dyld_image_mode mode, uint32_t infoCount, const struct dyld_image_info info[])
-{
- if ( fHasImageNotifySection ) {
- const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
- const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
- const struct load_command* cmd = cmds;
- for (unsigned long i = 0; i < cmd_count; ++i) {
- if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
- const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
- if ( strcmp(seg->segname, "__DATA") == 0 ) {
- 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) {
- if ( strcmp(sect->sectname, "__image_notify") == 0 ) {
- dyld_image_notifier* notes = (dyld_image_notifier*)(sect->addr + fSlide);
- const uint32_t count = sect->size / sizeof(uintptr_t);
- for (uint32_t i=count; i > 0; --i) {
- dyld_image_notifier func = notes[i-1];
- func(mode, infoCount, info);
- }
- }
- }
- }
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
- }
-}
-#endif
-
-void ImageLoaderMachO::printStatistics(unsigned int imageCount)
-{
- ImageLoader::printStatistics(imageCount);
- //dyld::log("total hinted binary tree searches: %d\n", fgHintedBinaryTreeSearchs);
- //dyld::log("total unhinted binary tree searches: %d\n", fgUnhintedBinaryTreeSearchs);
- dyld::log("total images with weak exports: %d\n", fgCountOfImagesWithWeakExports);
-
-#if LINKEDIT_USAGE_DEBUG
- dyld::log("linkedit pages accessed (%lu):\n", sLinkEditPageBuckets.size());
-#endif
-}
-
-
-ImageLoader::SegmentIterator ImageLoaderMachO::beginSegments() const
-{
- return SegmentIterator(fSegmentsArray);
-}
-
-ImageLoader::SegmentIterator ImageLoaderMachO::endSegments() const
-{
- return SegmentIterator(&fSegmentsArray[fSegmentsArrayCount]);
-}
-
-SegmentMachO::SegmentMachO(const struct macho_segment_command* cmd)
- : fSegmentLoadCommand(cmd)
-{
-}
-
-SegmentMachO::~SegmentMachO()
-{
-}
-
-void SegmentMachO::adjust(const struct macho_segment_command* cmd)
-{
- fSegmentLoadCommand = cmd;
-}
-void SegmentMachO::unmap(const ImageLoader* image)
+void ImageLoaderMachO::printStatistics(unsigned int imageCount, const InitializerTimingList& timingInfo)
{
- // update stats
- --ImageLoader::fgTotalSegmentsMapped;
- ImageLoader::fgTotalBytesMapped -= fSegmentLoadCommand->vmsize;
- munmap((void*)(this->getActualLoadAddress(image)), fSegmentLoadCommand->vmsize);
+ ImageLoader::printStatistics(imageCount, timingInfo);
+ dyld::log("total symbol trie searches: %d\n", fgSymbolTrieSearchs);
+ dyld::log("total symbol table binary searches: %d\n", fgSymbolTableBinarySearchs);
+ dyld::log("total images defining weak symbols: %u\n", fgImagesHasWeakDefinitions);
+ dyld::log("total images using weak symbols: %u\n", fgImagesRequiringCoalescing);
}
-const char* SegmentMachO::getName()
+intptr_t ImageLoaderMachO::assignSegmentAddresses(const LinkContext& context)
{
- return fSegmentLoadCommand->segname;
+ // preflight and calculate slide if needed
+ const bool inPIE = (fgNextPIEDylibAddress != 0);
+ intptr_t slide = 0;
+ if ( this->segmentsCanSlide() && this->segmentsMustSlideTogether() ) {
+ bool needsToSlide = false;
+ bool imageHasPreferredLoadAddress = segHasPreferredLoadAddress(0);
+ uintptr_t lowAddr = (unsigned long)(-1);
+ uintptr_t highAddr = 0;
+ for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+ const uintptr_t segLow = segPreferredLoadAddress(i);
+ const uintptr_t segHigh = dyld_page_round(segLow + segSize(i));
+ if ( segLow < highAddr ) {
+ if ( dyld_page_size > 4096 )
+ dyld::throwf("can't map segments into 16KB pages");
+ else
+ dyld::throwf("overlapping segments");
+ }
+ if ( segLow < lowAddr )
+ lowAddr = segLow;
+ if ( segHigh > highAddr )
+ highAddr = segHigh;
+
+ if ( needsToSlide || !imageHasPreferredLoadAddress || inPIE || !reserveAddressRange(segPreferredLoadAddress(i), segSize(i)) )
+ needsToSlide = true;
+ }
+ if ( needsToSlide ) {
+ // find a chunk of address space to hold all segments
+ uintptr_t addr = reserveAnAddressRange(highAddr-lowAddr, context);
+ slide = addr - lowAddr;
+ }
+ }
+ else if ( ! this->segmentsCanSlide() ) {
+ for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+ if ( strcmp(segName(i), "__PAGEZERO") == 0 )
+ continue;
+ if ( !reserveAddressRange(segPreferredLoadAddress(i), segSize(i)) )
+ dyld::throwf("can't map unslidable segment %s to 0x%lX with size 0x%lX", segName(i), segPreferredLoadAddress(i), segSize(i));
+ }
+ }
+ else {
+ throw "mach-o does not support independently sliding segments";
+ }
+ return slide;
}
-uintptr_t SegmentMachO::getSize()
-{
- return fSegmentLoadCommand->vmsize;
-}
-uintptr_t SegmentMachO::getFileSize()
+uintptr_t ImageLoaderMachO::reserveAnAddressRange(size_t length, const ImageLoader::LinkContext& context)
{
- return fSegmentLoadCommand->filesize;
+ vm_address_t addr = 0;
+ vm_size_t size = length;
+ // in PIE programs, load initial dylibs after main executable so they don't have fixed addresses either
+ if ( fgNextPIEDylibAddress != 0 ) {
+ // add small (0-3 pages) random padding between dylibs
+ addr = fgNextPIEDylibAddress + (__stack_chk_guard/fgNextPIEDylibAddress & (sizeof(long)-1))*dyld_page_size;
+ //dyld::log("padding 0x%08llX, guard=0x%08llX\n", (long long)(addr - fgNextPIEDylibAddress), (long long)(__stack_chk_guard));
+ kern_return_t r = vm_alloc(&addr, size, VM_FLAGS_FIXED | VM_MAKE_TAG(VM_MEMORY_DYLIB));
+ if ( r == KERN_SUCCESS ) {
+ fgNextPIEDylibAddress = addr + size;
+ return addr;
+ }
+ fgNextPIEDylibAddress = 0;
+ }
+ kern_return_t r = vm_alloc(&addr, size, VM_FLAGS_ANYWHERE | VM_MAKE_TAG(VM_MEMORY_DYLIB));
+ if ( r != KERN_SUCCESS )
+ throw "out of address space";
+
+ return addr;
}
-uintptr_t SegmentMachO::getFileOffset()
+bool ImageLoaderMachO::reserveAddressRange(uintptr_t start, size_t length)
{
- return fSegmentLoadCommand->fileoff;
+ vm_address_t addr = start;
+ vm_size_t size = length;
+ kern_return_t r = vm_alloc(&addr, size, VM_FLAGS_FIXED | VM_MAKE_TAG(VM_MEMORY_DYLIB));
+ if ( r != KERN_SUCCESS )
+ return false;
+ return true;
}
-bool SegmentMachO::readable()
-{
- return ( (fSegmentLoadCommand->initprot & VM_PROT_READ) != 0);
-}
-bool SegmentMachO::writeable()
-{
- return ((fSegmentLoadCommand->initprot & VM_PROT_WRITE) != 0);
-}
-bool SegmentMachO::executable()
+void ImageLoaderMachO::mapSegments(int fd, uint64_t offsetInFat, uint64_t lenInFat, uint64_t fileLen, const LinkContext& context)
{
- return ((fSegmentLoadCommand->initprot & VM_PROT_EXECUTE) != 0);
-}
+ // find address range for image
+ intptr_t slide = this->assignSegmentAddresses(context);
+ if ( context.verboseMapping ) {
+ if ( offsetInFat != 0 )
+ dyld::log("dyld: Mapping %s (slice offset=%llu)\n", this->getPath(), (unsigned long long)offsetInFat);
+ else
+ dyld::log("dyld: Mapping %s\n", this->getPath());
+ }
+ // map in all segments
+ for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+ vm_offset_t fileOffset = segFileOffset(i) + offsetInFat;
+ vm_size_t size = segFileSize(i);
+ uintptr_t requestedLoadAddress = segPreferredLoadAddress(i) + slide;
+ int protection = 0;
+ if ( !segUnaccessible(i) ) {
+ // If has text-relocs, don't set x-bit initially.
+ // Instead set it later after text-relocs have been done.
+ if ( segExecutable(i) && !(segHasRebaseFixUps(i) && (slide != 0)) )
+ protection |= PROT_EXEC;
+ if ( segReadable(i) )
+ protection |= PROT_READ;
+ if ( segWriteable(i) )
+ protection |= PROT_WRITE;
+ }
+ #if __i386__
+ // initially map __IMPORT segments R/W so dyld can update them
+ if ( segIsReadOnlyImport(i) )
+ protection |= PROT_WRITE;
+ #endif
+ // wholly zero-fill segments have nothing to mmap() in
+ if ( size > 0 ) {
+ if ( (fileOffset+size) > fileLen ) {
+ dyld::throwf("truncated mach-o error: segment %s extends to %llu which is past end of file %llu",
+ segName(i), (uint64_t)(fileOffset+size), fileLen);
+ }
+ void* loadAddress = xmmap((void*)requestedLoadAddress, size, protection, MAP_FIXED | MAP_PRIVATE, fd, fileOffset);
+ if ( loadAddress == ((void*)(-1)) ) {
+ dyld::throwf("mmap() error %d at address=0x%08lX, size=0x%08lX segment=%s in Segment::map() mapping %s",
+ errno, requestedLoadAddress, (uintptr_t)size, segName(i), getPath());
+ }
+ }
+ // update stats
+ ++ImageLoader::fgTotalSegmentsMapped;
+ ImageLoader::fgTotalBytesMapped += size;
+ if ( context.verboseMapping )
+ dyld::log("%18s at 0x%08lX->0x%08lX with permissions %c%c%c\n", segName(i), requestedLoadAddress, requestedLoadAddress+size-1,
+ (protection & PROT_READ) ? 'r' : '.', (protection & PROT_WRITE) ? 'w' : '.', (protection & PROT_EXEC) ? 'x' : '.' );
+ }
-bool SegmentMachO::unaccessible()
-{
- return (fSegmentLoadCommand->initprot == 0);
+ // update slide to reflect load location
+ this->setSlide(slide);
}
-#if TEXT_RELOC_SUPPORT
-bool SegmentMachO::hasFixUps()
+void ImageLoaderMachO::mapSegments(const void* memoryImage, uint64_t imageLen, const LinkContext& context)
{
- // scan sections for fix-up bit
- const struct macho_section* const sectionsStart = (struct macho_section*)((char*)fSegmentLoadCommand + sizeof(struct macho_segment_command));
- const struct macho_section* const sectionsEnd = §ionsStart[fSegmentLoadCommand->nsects];
- for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
- if ( (sect->flags & (S_ATTR_EXT_RELOC | S_ATTR_LOC_RELOC)) != 0 )
- return true;
+ // find address range for image
+ intptr_t slide = this->assignSegmentAddresses(context);
+ if ( context.verboseMapping )
+ dyld::log("dyld: Mapping memory %p\n", memoryImage);
+ // map in all segments
+ for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+ vm_address_t loadAddress = segPreferredLoadAddress(i) + slide;
+ vm_address_t srcAddr = (uintptr_t)memoryImage + segFileOffset(i);
+ vm_size_t size = segFileSize(i);
+ kern_return_t r = vm_copy(mach_task_self(), srcAddr, size, loadAddress);
+ if ( r != KERN_SUCCESS )
+ throw "can't map segment";
+ if ( context.verboseMapping )
+ dyld::log("%18s at 0x%08lX->0x%08lX\n", segName(i), (uintptr_t)loadAddress, (uintptr_t)loadAddress+size-1);
+ }
+ // update slide to reflect load location
+ this->setSlide(slide);
+ // set R/W permissions on all segments at slide location
+ for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+ segProtect(i, context);
}
- return false;
-}
-#endif
-
-#if __i386__
-bool SegmentMachO::readOnlyImportStubs()
-{
- return ( (fSegmentLoadCommand->initprot & VM_PROT_EXECUTE)
- && ((fSegmentLoadCommand->initprot & VM_PROT_WRITE) == 0)
- && (strcmp(fSegmentLoadCommand->segname, "__IMPORT") == 0) );
-}
-#endif
-
-uintptr_t SegmentMachO::getActualLoadAddress(const ImageLoader* inImage)
-{
- return fSegmentLoadCommand->vmaddr + inImage->getSlide();
}
-uintptr_t SegmentMachO::getPreferredLoadAddress()
-{
- return fSegmentLoadCommand->vmaddr;
-}
-bool SegmentMachO::hasPreferredLoadAddress()
+void ImageLoaderMachO::segProtect(unsigned int segIndex, const ImageLoader::LinkContext& context)
{
- return (fSegmentLoadCommand->vmaddr != 0);
-}
-
+ vm_prot_t protection = 0;
+ if ( !segUnaccessible(segIndex) ) {
+ if ( segExecutable(segIndex) )
+ protection |= PROT_EXEC;
+ if ( segReadable(segIndex) )
+ protection |= PROT_READ;
+ if ( segWriteable(segIndex) )
+ protection |= PROT_WRITE;
+ }
+ vm_address_t addr = segActualLoadAddress(segIndex);
+ vm_size_t size = segSize(segIndex);
+ const bool setCurrentPermissions = false;
+ kern_return_t r = vm_protect(mach_task_self(), addr, size, setCurrentPermissions, protection);
+ if ( r != KERN_SUCCESS ) {
+ dyld::throwf("vm_protect(0x%08llX, 0x%08llX, false, 0x%02X) failed, result=%d for segment %s in %s",
+ (long long)addr, (long long)size, protection, r, segName(segIndex), this->getPath());
+ }
+ if ( context.verboseMapping ) {
+ dyld::log("%18s at 0x%08lX->0x%08lX altered permissions to %c%c%c\n", segName(segIndex), (uintptr_t)addr, (uintptr_t)addr+size-1,
+ (protection & PROT_READ) ? 'r' : '.', (protection & PROT_WRITE) ? 'w' : '.', (protection & PROT_EXEC) ? 'x' : '.' );
+ }
+}
-Segment* SegmentMachO::next(Segment* location)
-{
- return &((SegmentMachO*)location)[1];
+void ImageLoaderMachO::segMakeWritable(unsigned int segIndex, const ImageLoader::LinkContext& context)
+{
+ vm_address_t addr = segActualLoadAddress(segIndex);
+ vm_size_t size = segSize(segIndex);
+ const bool setCurrentPermissions = false;
+ vm_prot_t protection = VM_PROT_WRITE | VM_PROT_READ;
+ if ( segExecutable(segIndex) && !segHasRebaseFixUps(segIndex) )
+ protection |= VM_PROT_EXECUTE;
+ kern_return_t r = vm_protect(mach_task_self(), addr, size, setCurrentPermissions, protection);
+ if ( r != KERN_SUCCESS ) {
+ dyld::throwf("vm_protect(0x%08llX, 0x%08llX, false, 0x%02X) failed, result=%d for segment %s in %s",
+ (long long)addr, (long long)size, protection, r, segName(segIndex), this->getPath());
+ }
+ if ( context.verboseMapping ) {
+ dyld::log("%18s at 0x%08lX->0x%08lX altered permissions to %c%c%c\n", segName(segIndex), (uintptr_t)addr, (uintptr_t)addr+size-1,
+ (protection & PROT_READ) ? 'r' : '.', (protection & PROT_WRITE) ? 'w' : '.', (protection & PROT_EXEC) ? 'x' : '.' );
+ }
}
-
-
-
-
projects / apple / dyld.git / blobdiff