/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
*
- * Copyright (c) 2006-2009 Apple Inc. All rights reserved.
+ * Copyright (c) 2006-2015 Apple Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
#include <sys/types.h>
#include <stdint.h>
#include <mach/shared_region.h>
+#include <uuid/uuid.h>
struct dyld_cache_header
uint64_t codeSignatureSize; // size of code signature blob (zero means to end of file)
uint64_t slideInfoOffset; // file offset of kernel slid info
uint64_t slideInfoSize; // size of kernel slid info
+ uint64_t localSymbolsOffset; // file offset of where local symbols are stored
+ uint64_t localSymbolsSize; // size of local symbols information
+ uint8_t uuid[16]; // unique value for each shared cache file
+ uint64_t cacheType; // 0 for development, 1 for production
+ uint32_t branchPoolsOffset; // file offset to table of uint64_t pool addresses
+ uint32_t branchPoolsCount; // number of uint64_t entries
+ uint64_t accelerateInfoAddr; // (unslid) address of optimization info
+ uint64_t accelerateInfoSize; // size of optimization info
+ uint64_t imagesTextOffset; // file offset to first dyld_cache_image_text_info
+ uint64_t imagesTextCount; // number of dyld_cache_image_text_info entries
};
+
struct dyld_cache_mapping_info {
uint64_t address;
uint64_t size;
uint32_t pad;
};
+struct dyld_cache_image_info_extra
+{
+ uint64_t exportsTrieAddr; // address of trie in unslid cache
+ uint64_t weakBindingsAddr;
+ uint32_t exportsTrieSize;
+ uint32_t weakBindingsSize;
+ uint32_t dependentsStartArrayIndex;
+ uint32_t reExportsStartArrayIndex;
+};
+
+
+struct dyld_cache_accelerator_info
+{
+ uint32_t version; // currently 1
+ uint32_t imageExtrasCount; // does not include aliases
+ uint32_t imagesExtrasOffset; // offset into this chunk of first dyld_cache_image_info_extra
+ uint32_t bottomUpListOffset; // offset into this chunk to start of 16-bit array of sorted image indexes
+ uint32_t dylibTrieOffset; // offset into this chunk to start of trie containing all dylib paths
+ uint32_t dylibTrieSize; // size of trie containing all dylib paths
+ uint32_t initializersOffset; // offset into this chunk to start of initializers list
+ uint32_t initializersCount; // size of initializers list
+ uint32_t dofSectionsOffset; // offset into this chunk to start of DOF sections list
+ uint32_t dofSectionsCount; // size of initializers list
+ uint32_t reExportListOffset; // offset into this chunk to start of 16-bit array of re-exports
+ uint32_t reExportCount; // size of re-exports
+ uint32_t depListOffset; // offset into this chunk to start of 16-bit array of dependencies (0x8000 bit set if upward)
+ uint32_t depListCount; // size of dependencies
+ uint32_t rangeTableOffset; // offset into this chunk to start of ss
+ uint32_t rangeTableCount; // size of dependencies
+ uint64_t dyldSectionAddr; // address of libdyld's __dyld section in unslid cache
+};
+
+struct dyld_cache_accelerator_initializer
+{
+ uint32_t functionOffset; // address offset from start of cache mapping
+ uint32_t imageIndex;
+};
+
+struct dyld_cache_range_entry
+{
+ uint64_t startAddress; // unslid address of start of region
+ uint32_t size;
+ uint32_t imageIndex;
+};
+
+struct dyld_cache_accelerator_dof
+{
+ uint64_t sectionAddress; // unslid address of start of region
+ uint32_t sectionSize;
+ uint32_t imageIndex;
+};
+
+struct dyld_cache_image_text_info
+{
+ uuid_t uuid;
+ uint64_t loadAddress; // unslid address of start of __TEXT
+ uint32_t textSegmentSize;
+ uint32_t pathOffset; // offset from start of cache file
+};
+
+// The rebasing info is to allow the kernel to lazily rebase DATA pages of the
+// dyld shared cache. Rebasing is adding the slide to interior pointers.
struct dyld_cache_slide_info
{
uint32_t version; // currently 1
};
+// The version 2 of the slide info uses a different compression scheme. Since
+// only interior pointers (pointers that point within the cache) are rebased
+// (slid), we know the possible range of the pointers and thus know there are
+// unused bits in each pointer. We use those bits to form a linked list of
+// locations needing rebasing in each page.
+//
+// Definitions:
+//
+// pageIndex = (pageAddress - startOfAllDataAddress)/info->page_size
+// pageStarts[] = info + info->page_starts_offset
+// pageExtras[] = info + info->page_extras_offset
+// valueMask = ~(info->delta_mask)
+// deltaShift = __builtin_ctzll(info->delta_mask) - 2
+//
+// There are three cases:
+//
+// 1) pageStarts[pageIndex] == DYLD_CACHE_SLIDE_PAGE_ATTR_NO_REBASE
+// The page contains no values that need rebasing.
+//
+// 2) (pageStarts[pageIndex] & DYLD_CACHE_SLIDE_PAGE_ATTR_EXTRA) == 0
+// All rebase locations are in one linked list. The offset of the first
+// rebase location in the page is pageStarts[pageIndex] * 4.
+//
+// 3) pageStarts[pageIndex] & DYLD_CACHE_SLIDE_PAGE_ATTR_EXTRA
+// Multiple linked lists are needed for all rebase locations in a page.
+// The pagesExtras array contains 2 or more entries each of which is the
+// start of a new linked list in the page. The first is at:
+// extrasStartIndex = (pageStarts[pageIndex] & 0x3FFF)
+// The next is at extrasStartIndex+1. The last is denoted by
+// having the high bit (DYLD_CACHE_SLIDE_PAGE_ATTR_END) of the pageExtras[]
+// set.
+//
+// For 64-bit architectures, there is always enough free bits to encode all
+// possible deltas. The info->delta_mask field shows where the delta is located
+// in the pointer. That value must be masked off (valueMask) before the slide
+// is added to the pointer.
+//
+// For 32-bit architectures, there are only three bits free (the three most
+// significant bits). To extract the delta, you must first subtract value_add
+// from the pointer value, then AND with delta_mask, then shift by deltaShift.
+// That still leaves a maximum delta to the next rebase location of 28 bytes.
+// To reduce the number or chains needed, an optimization was added. Turns
+// out zero is common in the DATA region. A zero can be turned into a
+// non-rebasing entry in the linked list. The can be done because nothing
+// in the shared cache should point out of its dylib to the start of the shared
+// cache.
+//
+// The code for processing a linked list (chain) is:
+//
+// uint32_t delta = 1;
+// while ( delta != 0 ) {
+// uint8_t* loc = pageStart + pageOffset;
+// uintptr_t rawValue = *((uintptr_t*)loc);
+// delta = ((rawValue & deltaMask) >> deltaShift);
+// uintptr_t newValue = (rawValue & valueMask);
+// if ( newValue != 0 ) {
+// newValue += valueAdd;
+// newValue += slideAmount;
+// }
+// *((uintptr_t*)loc) = newValue;
+// pageOffset += delta;
+// }
+//
+//
+struct dyld_cache_slide_info2
+{
+ uint32_t version; // currently 2
+ uint32_t page_size; // currently 4096 (may also be 16384)
+ uint32_t page_starts_offset;
+ uint32_t page_starts_count;
+ uint32_t page_extras_offset;
+ uint32_t page_extras_count;
+ uint64_t delta_mask; // which (contiguous) set of bits contains the delta to the next rebase location
+ uint64_t value_add;
+ //uint16_t page_starts[page_starts_count];
+ //uint16_t page_extras[page_extras_count];
+};
+#define DYLD_CACHE_SLIDE_PAGE_ATTRS 0xC000 // high bits of uint16_t are flags
+#define DYLD_CACHE_SLIDE_PAGE_ATTR_EXTRA 0x8000 // index is into extras array (not starts array)
+#define DYLD_CACHE_SLIDE_PAGE_ATTR_NO_REBASE 0x4000 // page has no rebasing
+#define DYLD_CACHE_SLIDE_PAGE_ATTR_END 0x8000 // last chain entry for page
+
+
+struct dyld_cache_local_symbols_info
+{
+ uint32_t nlistOffset; // offset into this chunk of nlist entries
+ uint32_t nlistCount; // count of nlist entries
+ uint32_t stringsOffset; // offset into this chunk of string pool
+ uint32_t stringsSize; // byte count of string pool
+ uint32_t entriesOffset; // offset into this chunk of array of dyld_cache_local_symbols_entry
+ uint32_t entriesCount; // number of elements in dyld_cache_local_symbols_entry array
+};
+
+struct dyld_cache_local_symbols_entry
+{
+ uint32_t dylibOffset; // offset in cache file of start of dylib
+ uint32_t nlistStartIndex; // start index of locals for this dylib
+ uint32_t nlistCount; // number of local symbols for this dylib
+};
+
+
-#define MACOSX_DYLD_SHARED_CACHE_DIR "/var/db/dyld/"
+#define MACOSX_DYLD_SHARED_CACHE_DIR "/private/var/db/dyld/"
#define IPHONE_DYLD_SHARED_CACHE_DIR "/System/Library/Caches/com.apple.dyld/"
#define DYLD_SHARED_CACHE_BASE_NAME "dyld_shared_cache_"
+#define DYLD_SHARED_CACHE_DEVELOPMENT_EXT ".development"
+
+static const uint64_t kDyldSharedCacheTypeDevelopment = 0;
+static const uint64_t kDyldSharedCacheTypeProduction = 1;
+
projects / apple / dyld.git / blobdiff