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/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef __ASM_UACCESS_ASM_H__
#define __ASM_UACCESS_ASM_H__
#include <asm/asm-offsets.h>
#include <asm/domain.h>
#include <asm/memory.h>
#include <asm/thread_info.h>
.macro csdb
#ifdef CONFIG_THUMB2_KERNEL
.inst.w 0xf3af8014
#else
.inst 0xe320f014
#endif
.endm
.macro check_uaccess, addr:req, size:req, limit:req, tmp:req, bad:req
#ifndef CONFIG_CPU_USE_DOMAINS
adds \tmp, \addr, #\size - 1
sbcscc \tmp, \tmp, \limit
bcs \bad
#ifdef CONFIG_CPU_SPECTRE
movcs \addr, #0
csdb
#endif
#endif
.endm
.macro uaccess_mask_range_ptr, addr:req, size:req, limit:req, tmp:req
#ifdef CONFIG_CPU_SPECTRE
sub \tmp, \limit, #1
subs \tmp, \tmp, \addr @ tmp = limit - 1 - addr
addhs \tmp, \tmp, #1 @ if (tmp >= 0) {
subshs \tmp, \tmp, \size @ tmp = limit - (addr + size) }
movlo \addr, #0 @ if (tmp < 0) addr = NULL
csdb
#endif
.endm
.macro uaccess_disable, tmp, isb=1
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
/*
* Whenever we re-enter userspace, the domains should always be
* set appropriately.
*/
mov \tmp, #DACR_UACCESS_DISABLE
mcr p15, 0, \tmp, c3, c0, 0 @ Set domain register
.if \isb
instr_sync
.endif
#endif
.endm
.macro uaccess_enable, tmp, isb=1
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
/*
* Whenever we re-enter userspace, the domains should always be
* set appropriately.
*/
mov \tmp, #DACR_UACCESS_ENABLE
mcr p15, 0, \tmp, c3, c0, 0
.if \isb
instr_sync
.endif
#endif
.endm
.macro uaccess_save, tmp
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
mrc p15, 0, \tmp, c3, c0, 0
str \tmp, [sp, #SVC_DACR]
#endif
.endm
.macro uaccess_restore
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
ldr r0, [sp, #SVC_DACR]
mcr p15, 0, r0, c3, c0, 0
#endif
.endm
/*
* Save the address limit on entry to a privileged exception and
* if using PAN, save and disable usermode access.
*/
.macro uaccess_entry, tsk, tmp0, tmp1, tmp2, disable
ldr \tmp0, [\tsk, #TI_ADDR_LIMIT]
mov \tmp1, #TASK_SIZE
str \tmp1, [\tsk, #TI_ADDR_LIMIT]
str \tmp0, [sp, #SVC_ADDR_LIMIT]
uaccess_save \tmp0
.if \disable
uaccess_disable \tmp0
.endif
.endm
/* Restore the user access state previously saved by uaccess_entry */
.macro uaccess_exit, tsk, tmp0, tmp1
ldr \tmp1, [sp, #SVC_ADDR_LIMIT]
uaccess_restore
str \tmp1, [\tsk, #TI_ADDR_LIMIT]
.endm
#endif /* __ASM_UACCESS_ASM_H__ */
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