#include <Base.h>
#include <IndustryStandard/AppleKmodInfo.h>
#include <IndustryStandard/AppleMachoImage.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/BaseOverflowLib.h>
#include <Library/DebugLib.h>
#include <Library/OcAppleKernelLib.h>
#include <Library/OcMachoLib.h>
#include <Library/OcFileLib.h>
#include "PrelinkedInternal.h"

Macros
#define	TEXT_SEG_PROT (MACH_SEGMENT_VM_PROT_READ \| MACH_SEGMENT_VM_PROT_EXECUTE)

#define	DATA_SEG_PROT (MACH_SEGMENT_VM_PROT_READ \| MACH_SEGMENT_VM_PROT_WRITE)

#define	MATCH(X)

Functions
STATIC CONST PRELINKED_KEXT_SYMBOL *	InternalOcGetSymbolWorkerName (IN PRELINKED_KEXT Kext, IN CONST CHAR8 LookupValue, IN UINT32 LookupValueLength, IN OC_GET_SYMBOL_LEVEL SymbolLevel)

STATIC CONST PRELINKED_KEXT_SYMBOL *	InternalOcGetSymbolWorkerValue (IN PRELINKED_KEXT *Kext, IN UINT64 LookupValue, IN OC_GET_SYMBOL_LEVEL SymbolLevel)

CONST PRELINKED_KEXT_SYMBOL *	InternalOcGetSymbolName (IN PRELINKED_CONTEXT Context, IN PRELINKED_KEXT Kext, IN CONST CHAR8 *LookupValue, IN OC_GET_SYMBOL_LEVEL SymbolLevel)

CONST PRELINKED_KEXT_SYMBOL *	InternalOcGetSymbolValue (IN PRELINKED_CONTEXT Context, IN PRELINKED_KEXT Kext, IN UINT64 LookupValue, IN OC_GET_SYMBOL_LEVEL SymbolLevel)

VOID	InternalSolveSymbolValue (IN BOOLEAN Is32Bit, IN UINT64 Value, OUT MACH_NLIST_ANY *Symbol)

STATIC BOOLEAN	InternalSolveSymbolNonWeak (IN PRELINKED_CONTEXT Context, IN PRELINKED_KEXT Kext, IN CONST CHAR8 Name, IN OUT MACH_NLIST_ANY Symbol)

STATIC BOOLEAN	InternalSolveSymbol (IN PRELINKED_CONTEXT Context, IN PRELINKED_KEXT Kext, IN CONST CHAR8 Name, IN OUT MACH_NLIST_ANY Symbol, IN OUT UINT64 WeakTestValue, IN CONST MACH_NLIST_ANY UndefinedSymbols, IN UINT32 NumUndefinedSymbols)

STATIC BOOLEAN	InternalCalculateDisplacementIntel64 (IN UINT64 Target, IN UINT64 Adjustment, IN OUT INT32 *Instruction)

STATIC BOOLEAN	InternalCalculateTargets (IN PRELINKED_CONTEXT Context, IN OUT PRELINKED_KEXT Kext, IN UINT64 LoadAddress, IN CONST MACH_RELOCATION_INFO Relocation, IN CONST MACH_RELOCATION_INFO NextRelocation OPTIONAL, OUT UINT64 Target, OUT UINT64 PairTarget, OUT CONST PRELINKED_VTABLE **Vtable OPTIONAL)

STATIC BOOLEAN	InternalIsDirectPureVirtualCall (IN BOOLEAN Is32Bit, IN CONST PRELINKED_VTABLE *Vtable, IN UINT64 Offset)

STATIC UINTN	InternalRelocateRelocation (IN PRELINKED_CONTEXT Context, IN PRELINKED_KEXT Kext, IN UINT64 LoadAddress, IN UINT64 RelocationBase, IN CONST MACH_RELOCATION_INFO Relocation, IN CONST MACH_RELOCATION_INFO NextRelocation OPTIONAL)

STATIC BOOLEAN	InternalRelocateAndCopyRelocations (IN PRELINKED_CONTEXT Context, IN PRELINKED_KEXT Kext, IN UINT64 LoadAddress, IN UINT64 RelocationBase, IN CONST MACH_RELOCATION_INFO SourceRelocations, IN OUT UINT32 NumRelocations, OUT MACH_RELOCATION_INFO *TargetRelocations)

STATIC BOOLEAN	InternalRelocateSymbol (IN OC_MACHO_CONTEXT MachoContext, IN UINT64 LoadAddress, IN OUT MACH_NLIST_ANY Symbol, IN OUT UINT32 *KmodInfoOffset)

STATIC BOOLEAN	InternalRelocateSymbols (IN OC_MACHO_CONTEXT MachoContext, IN UINT64 LoadAddress, IN UINT32 NumSymbols, IN OUT MACH_NLIST_ANY Symbols, OUT UINT32 *KmodInfoOffset)

STATIC BOOLEAN	InternalProcessSymbolPointers (IN OC_MACHO_CONTEXT MachoContext, IN CONST MACH_DYSYMTAB_COMMAND DySymtab, IN UINT64 LoadAddress)

EFI_STATUS	InternalPrelinkKext (IN OUT PRELINKED_CONTEXT Context, IN PRELINKED_KEXT Kext, IN UINT64 LoadAddress, IN UINT64 FileOffset)

Detailed Description

Library handling KEXT prelinking.

Copyright (c) 2018, Download-Fritz. All rights reserved.
This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at http://opensource.org/licenses/bsd-license.php.

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

Definition in file Link.c.

Macro Definition Documentation

◆ DATA_SEG_PROT

#define DATA_SEG_PROT (MACH_SEGMENT_VM_PROT_READ | MACH_SEGMENT_VM_PROT_WRITE)

Definition at line 32 of file Link.c.

◆ MATCH

#define MATCH ( X )

Value:

if (Symbols[X].Value == LookupValue) { return &Symbols[X]; }

◆ TEXT_SEG_PROT

#define TEXT_SEG_PROT (MACH_SEGMENT_VM_PROT_READ | MACH_SEGMENT_VM_PROT_EXECUTE)

Definition at line 31 of file Link.c.

Function Documentation

◆ InternalCalculateDisplacementIntel64()

STATIC BOOLEAN InternalCalculateDisplacementIntel64	(	IN UINT64	Target,
		IN UINT64	Adjustment,
		IN OUT INT32 *	Instruction )

Calculate the target address' displacement for the Intel 64 platform. Instruction will be patched with the resulting address. Logically matches XNU's calculate_displacement_x86_64.

Parameters

[in]	Target	The target address.
[in]	Adjustment	Adjustment to be subtracted from the displacement.
[in,out]	Instruction	Pointer to the instruction to be patched.

Return values

Returned is whether the target instruction has been patched.

Definition at line 554 of file Link.c.

◆ InternalCalculateTargets()

STATIC BOOLEAN InternalCalculateTargets	(	IN PRELINKED_CONTEXT *	Context,
		IN OUT PRELINKED_KEXT *	Kext,
		IN UINT64	LoadAddress,
		IN CONST MACH_RELOCATION_INFO *	Relocation,
		IN CONST MACH_RELOCATION_INFO *NextRelocation	OPTIONAL,
		OUT UINT64 *	Target,
		OUT UINT64 *	PairTarget,
		OUT CONST PRELINKED_VTABLE **Vtable	OPTIONAL )

Calculate the target addresses for Relocation and NextRelocation. Logically matches XNU's calculate_targets.

Parameters

[in,out]	Context	Prelinking context.
[in]	Kext	KEXT prelinking context.
[in]	LoadAddress	The address to be linked against.
[in]	Relocation	The Relocation to be resolved.
[in]	NextRelocation	The Relocation following Relocation.
[out]	Target	Relocation's target address.
[out]	PairTarget	NextRelocation's target address.
[out]	Vtable	The VTable described by the symbol referenced by Relocation. NULL, if there is none.

Returns: Whether the operation was completed successfully.

Definition at line 596 of file Link.c.

◆ InternalIsDirectPureVirtualCall()

STATIC BOOLEAN InternalIsDirectPureVirtualCall	(	IN BOOLEAN	Is32Bit,
		IN CONST PRELINKED_VTABLE *	Vtable,
		IN UINT64	Offset )

Returns whether the VTable entry at Offset is a direct pure virtual call. Logically macthes XNU's check_for_direct_pure_virtual_call.

Parameters

[in]	Vtable	The current VTable to be inspected.
[in]	Offset	The VTable's entry offset.

Definition at line 741 of file Link.c.

◆ InternalOcGetSymbolName()

CONST PRELINKED_KEXT_SYMBOL * InternalOcGetSymbolName	(	IN PRELINKED_CONTEXT *	Context,
		IN PRELINKED_KEXT *	Kext,
		IN CONST CHAR8 *	LookupValue,
		IN OC_GET_SYMBOL_LEVEL	SymbolLevel )

Definition at line 191 of file Link.c.

◆ InternalOcGetSymbolValue()

CONST PRELINKED_KEXT_SYMBOL * InternalOcGetSymbolValue	(	IN PRELINKED_CONTEXT *	Context,
		IN PRELINKED_KEXT *	Kext,
		IN UINT64	LookupValue,
		IN OC_GET_SYMBOL_LEVEL	SymbolLevel )

Definition at line 246 of file Link.c.

◆ InternalOcGetSymbolWorkerName()

STATIC CONST PRELINKED_KEXT_SYMBOL * InternalOcGetSymbolWorkerName	(	IN PRELINKED_KEXT *	Kext,
		IN CONST CHAR8 *	LookupValue,
		IN UINT32	LookupValueLength,
		IN OC_GET_SYMBOL_LEVEL	SymbolLevel )

Definition at line 40 of file Link.c.

◆ InternalOcGetSymbolWorkerValue()

STATIC CONST PRELINKED_KEXT_SYMBOL * InternalOcGetSymbolWorkerValue	(	IN PRELINKED_KEXT *	Kext,
		IN UINT64	LookupValue,
		IN OC_GET_SYMBOL_LEVEL	SymbolLevel )

Definition at line 122 of file Link.c.

◆ InternalPrelinkKext()

EFI_STATUS InternalPrelinkKext	(	IN OUT PRELINKED_CONTEXT *	Context,
		IN PRELINKED_KEXT *	Kext,
		IN UINT64	LoadAddress,
		IN UINT64	FileOffset )

Prelinks the specified KEXT against the specified LoadAddress and the data of its dependencies.

Parameters

[in,out]	Context	Prelinking context.
[in]	Kext	KEXT prelinking context.
[in]	LoadAddress	The address this KEXT shall be linked against.
[in]	FileOffset	The file offset of the first segment.

Return values

Returned is whether the prelinking process has been successful. The state of the KEXT is undefined in case this routine fails.

Definition at line 1503 of file Link.c.

◆ InternalProcessSymbolPointers()

STATIC BOOLEAN InternalProcessSymbolPointers	(	IN OC_MACHO_CONTEXT *	MachoContext,
		IN CONST MACH_DYSYMTAB_COMMAND *	DySymtab,
		IN UINT64	LoadAddress )

process_symbol_pointers

Definition at line 1384 of file Link.c.

◆ InternalRelocateAndCopyRelocations()

STATIC BOOLEAN InternalRelocateAndCopyRelocations	(	IN PRELINKED_CONTEXT *	Context,
		IN PRELINKED_KEXT *	Kext,
		IN UINT64	LoadAddress,
		IN UINT64	RelocationBase,
		IN CONST MACH_RELOCATION_INFO *	SourceRelocations,
		IN OUT UINT32 *	NumRelocations,
		OUT MACH_RELOCATION_INFO *	TargetRelocations )

Relocates all Mach-O Relocations and copies the ones to be preserved after prelinking to TargetRelocations.

Parameters

[in,out]	Context	Prelinking context.
[in]	Kext	KEXT prelinking context.
[in]	LoadAddress	The address to be linked against. dependencies.
[in]	RelocationBase	The Relocations base address.
[in]	SourceRelocations	The Relocations source buffer.
[in]	NumRelocations	On input, the number of source Relocations. On output, the number of Relocations to preserve.
[out]	TargetRelocations	The Relocations destination buffer.

Return values

Returned is the number of preserved Relocations.

Definition at line 1106 of file Link.c.

◆ InternalRelocateRelocation()

STATIC UINTN InternalRelocateRelocation	(	IN PRELINKED_CONTEXT *	Context,
		IN PRELINKED_KEXT *	Kext,
		IN UINT64	LoadAddress,
		IN UINT64	RelocationBase,
		IN CONST MACH_RELOCATION_INFO *	Relocation,
		IN CONST MACH_RELOCATION_INFO *NextRelocation	OPTIONAL )

Relocates Relocation against the specified Symtab's Symbol Table and LoadAddress. This logically matches KXLD's generic_process_reloc (for 32-bit) and x86_64_process_reloc (for 64-bit).

Parameters

[in,out]	Context	Prelinking context.
[in]	Kext	KEXT prelinking context.
[in]	LoadAddress	The address to be linked against.
[in]	RelocationBase	The Relocations base address.
[in]	Relocation	The Relocation to be processed.
[in]	NextRelocation	The Relocation following Relocation.

Return values

0	The Relocation does not need to be preseved.
1	The Relocation must be preseved.
0	\| BIT31 The Relocation does not need to be preseved. The next Relocation shall be skipped.
1	\| BIT31 The Relocation must be preseved. The next Relocation shall be skipped.
MAX_UINTN	The Relocation's target cannot be determined or it is a direct pure virtual call.

Definition at line 793 of file Link.c.

◆ InternalRelocateSymbol()

STATIC BOOLEAN InternalRelocateSymbol	(	IN OC_MACHO_CONTEXT *	MachoContext,
		IN UINT64	LoadAddress,
		IN OUT MACH_NLIST_ANY *	Symbol,
		IN OUT UINT32 *	KmodInfoOffset )

Definition at line 1264 of file Link.c.

◆ InternalRelocateSymbols()

STATIC BOOLEAN InternalRelocateSymbols	(	IN OC_MACHO_CONTEXT *	MachoContext,
		IN UINT64	LoadAddress,
		IN UINT32	NumSymbols,
		IN OUT MACH_NLIST_ANY *	Symbols,
		OUT UINT32 *	KmodInfoOffset )

Definition at line 1309 of file Link.c.

◆ InternalSolveSymbol()

STATIC BOOLEAN InternalSolveSymbol	(	IN PRELINKED_CONTEXT *	Context,
		IN PRELINKED_KEXT *	Kext,
		IN CONST CHAR8 *	Name,
		IN OUT MACH_NLIST_ANY *	Symbol,
		IN OUT UINT64 *	WeakTestValue,
		IN CONST MACH_NLIST_ANY *	UndefinedSymbols,
		IN UINT32	NumUndefinedSymbols )

Solves Symbol against the specified DefinedSymbols.

Parameters

[in,out]	Context	Prelinking context.
[in]	Kext	KEXT prelinking context.
[in]	Name	The name of the symbol to resolve against.
[in,out]	Symbol	The symbol to be resolved.
[in,out]	WeakTestValue	Points to the value of the Weak test symbol. If it is 0 on input, it will get assigned the value on the first resolution of a weak symbol.
[in]	UndefinedSymbols	Array of the Mach-O'S undefined symbols.
[in]	NumUndefinedSymbols	Number of symbols in UndefinedSymbols.

Return values

Returned is whether the symbol was solved successfully. For weak symbols, this includes solving with _gOSKextUnresolved.

Definition at line 404 of file Link.c.

◆ InternalSolveSymbolNonWeak()

STATIC BOOLEAN InternalSolveSymbolNonWeak	(	IN PRELINKED_CONTEXT *	Context,
		IN PRELINKED_KEXT *	Kext,
		IN CONST CHAR8 *	Name,
		IN OUT MACH_NLIST_ANY *	Symbol )

Worker function to solve Symbol against the specified DefinedSymbols. It does not consider Symbol might be a weak reference.

Parameters

[in,out]	Context	Prelinking context.
[in]	Kext	KEXT prelinking context.
[in]	Name	The name of the symbol to resolve against.
[in,out]	Symbol	The symbol to be resolved.

Return values

Returned is whether the symbol was solved successfully.

Definition at line 325 of file Link.c.

◆ InternalSolveSymbolValue()

VOID InternalSolveSymbolValue	(	IN BOOLEAN	Is32Bit,
		IN UINT64	Value,
		OUT MACH_NLIST_ANY *	Symbol )

Patches Symbol with Value and marks it as solved.

Parameters

[in]	Is32Bit	Symbol is 32-bit.
[in]	Value	The value to solve Symbol with.
[out]	Symbol	The symbol to solve.

Definition at line 294 of file Link.c.

Macros

Functions

Detailed Description

Macro Definition Documentation

◆ DATA_SEG_PROT

◆ MATCH

◆ TEXT_SEG_PROT

Function Documentation

◆ InternalCalculateDisplacementIntel64()

◆ InternalCalculateTargets()

◆ InternalIsDirectPureVirtualCall()

◆ InternalOcGetSymbolName()

◆ InternalOcGetSymbolValue()

◆ InternalOcGetSymbolWorkerName()

◆ InternalOcGetSymbolWorkerValue()

◆ InternalPrelinkKext()

◆ InternalProcessSymbolPointers()

◆ InternalRelocateAndCopyRelocations()

◆ InternalRelocateRelocation()

◆ InternalRelocateSymbol()

◆ InternalRelocateSymbols()

◆ InternalSolveSymbol()

◆ InternalSolveSymbolNonWeak()

◆ InternalSolveSymbolValue()