darling-xnu/osfmk/arm64/pac_asm.h
2023-05-16 21:41:14 -07:00

144 lines
4.6 KiB
C

/*
* Copyright (c) 2019 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
#ifndef _ARM64_PAC_ASM_H_
#define _ARM64_PAC_ASM_H_
#ifndef __ASSEMBLER__
#error "This header should only be used in .s files"
#endif
#include <pexpert/arm64/board_config.h>
#include <arm64/proc_reg.h>
#if HAS_PARAVIRTUALIZED_PAC
#include "smccc_asm.h"
#endif
#include "assym.s"
#if defined(HAS_APPLE_PAC)
/* BEGIN IGNORE CODESTYLE */
/**
* REPROGRAM_JOP_KEYS
*
* Loads a userspace process's JOP key (task->jop_pid) into the CPU, and
* updates current_cpu_datap()->jop_key accordingly. This reprogramming process
* is skipped whenever the "new" JOP key has already been loaded into the CPU.
*
* skip_label - branch to this label if new_jop_key is already loaded into CPU
* new_jop_key - process's jop_pid
* cpudatap - current cpu_data_t *
* tmp - scratch register
*/
.macro REPROGRAM_JOP_KEYS skip_label, new_jop_key, cpudatap, tmp
ldr \tmp, [\cpudatap, CPU_JOP_KEY]
cmp \new_jop_key, \tmp
b.eq \skip_label
SET_JOP_KEY_REGISTERS \new_jop_key, \tmp
str \new_jop_key, [\cpudatap, CPU_JOP_KEY]
.endmacro
/**
* REPROGRAM_ROP_KEYS
*
* Loads a userspace process's ROP key (task->rop_pid) into the CPU, and
* updates current_cpu_datap()->rop_key accordingly. This reprogramming process
* is skipped whenever the "new" ROP key has already been loaded into the CPU.
*
* skip_label - branch to this label if new_rop_key is already loaded into CPU
* new_rop_key - process's rop_pid
* cpudatap - current cpu_data_t *
* tmp - scratch register
*/
.macro REPROGRAM_ROP_KEYS skip_label, new_rop_key, cpudatap, tmp
ldr \tmp, [\cpudatap, CPU_ROP_KEY]
cmp \new_rop_key, \tmp
b.eq \skip_label
SET_ROP_KEY_REGISTERS \new_rop_key, \tmp
str \new_rop_key, [\cpudatap, CPU_ROP_KEY]
.endmacro
/**
* SET_JOP_KEY_REGISTERS
*
* Unconditionally loads a userspace process's JOP key (task->jop_pid) into the
* CPU. The caller is responsible for updating current_cpu_datap()->jop_key as
* needed.
*
* new_jop_key - process's jop_pid
* tmp - scratch register
*/
.macro SET_JOP_KEY_REGISTERS new_jop_key, tmp
#if HAS_PARAVIRTUALIZED_PAC
SAVE_SMCCC_CLOBBERED_REGISTERS
/*
* We're deliberately calling PAC_SET_EL0_DIVERSIFIER here, even though the
* EL0 diversifier affects both A (JOP) and B (ROP) keys. We don't want
* SET_JOP_KEY_REGISTERS to have an impact on the EL1 A key state, since
* these are the keys the kernel uses to sign pointers on the heap.
*
* Using new_jop_key as the EL0 diversifer has the same net effect of giving
* userspace its own set of JOP keys, but doesn't affect EL1 A key state.
*/
MOV64 x0, VMAPPLE_PAC_SET_EL0_DIVERSIFIER
mov x1, \new_jop_key
hvc #0
LOAD_SMCCC_CLOBBERED_REGISTERS
#endif /* HAS_PARAVIRTUALIZED_PAC */
.endmacro
/**
* SET_ROP_KEY_REGISTERS
*
* Unconditionally loads a userspace process's ROP key (task->rop_pid) into the
* CPU. The caller is responsible for updating current_cpu_datap()->rop_key as
* needed.
*
* new_rop_key - process's rop_pid
* tmp - scratch register
*/
.macro SET_ROP_KEY_REGISTERS new_rop_key, tmp
#if HAS_PARAVIRTUALIZED_PAC
SAVE_SMCCC_CLOBBERED_REGISTERS
MOV64 x0, VMAPPLE_PAC_SET_B_KEYS
mov x1, \new_rop_key
hvc #0
LOAD_SMCCC_CLOBBERED_REGISTERS
#endif /* HAS_PARAVIRTUALIZED_PAC */
.endmacro
/* END IGNORE CODESTYLE */
#endif /* defined(HAS_APPLE_PAC) */
#endif /* _ARM64_PAC_ASM_H_ */
/* vim: set ts=4 ft=asm: */