linux/arch/arm64/include/asm/asm-uaccess.h
Al Viro b4b8664d29 arm64: don't pull uaccess.h into *.S
Split asm-only parts of arm64 uaccess.h into a new header and use that
from *.S.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-26 13:05:17 -05:00

66 lines
1.5 KiB
C

#ifndef __ASM_ASM_UACCESS_H
#define __ASM_ASM_UACCESS_H
#include <asm/alternative.h>
#include <asm/kernel-pgtable.h>
#include <asm/sysreg.h>
#include <asm/assembler.h>
/*
* User access enabling/disabling macros.
*/
#ifdef CONFIG_ARM64_SW_TTBR0_PAN
.macro __uaccess_ttbr0_disable, tmp1
mrs \tmp1, ttbr1_el1 // swapper_pg_dir
add \tmp1, \tmp1, #SWAPPER_DIR_SIZE // reserved_ttbr0 at the end of swapper_pg_dir
msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1
isb
.endm
.macro __uaccess_ttbr0_enable, tmp1
get_thread_info \tmp1
ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1
msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1
isb
.endm
.macro uaccess_ttbr0_disable, tmp1
alternative_if_not ARM64_HAS_PAN
__uaccess_ttbr0_disable \tmp1
alternative_else_nop_endif
.endm
.macro uaccess_ttbr0_enable, tmp1, tmp2
alternative_if_not ARM64_HAS_PAN
save_and_disable_irq \tmp2 // avoid preemption
__uaccess_ttbr0_enable \tmp1
restore_irq \tmp2
alternative_else_nop_endif
.endm
#else
.macro uaccess_ttbr0_disable, tmp1
.endm
.macro uaccess_ttbr0_enable, tmp1, tmp2
.endm
#endif
/*
* These macros are no-ops when UAO is present.
*/
.macro uaccess_disable_not_uao, tmp1
uaccess_ttbr0_disable \tmp1
alternative_if ARM64_ALT_PAN_NOT_UAO
SET_PSTATE_PAN(1)
alternative_else_nop_endif
.endm
.macro uaccess_enable_not_uao, tmp1, tmp2
uaccess_ttbr0_enable \tmp1, \tmp2
alternative_if ARM64_ALT_PAN_NOT_UAO
SET_PSTATE_PAN(0)
alternative_else_nop_endif
.endm
#endif