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ARM: uaccess: integrate uaccess_save and uaccess_restore

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Integrate uaccess_save / uaccess_restore macros into the new
uaccess_entry / uaccess_exit macros respectively.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Russell King 2020-05-03 13:14:09 +01:00
parent 747ffc2fcf
commit 8ede890b0b
1 changed files with 13 additions and 17 deletions
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30
arch/arm/include/asm/uaccess-asm.h
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@ -67,30 +67,23 @@
#endif
.endm
.macro uaccess_save, tmp
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
mrc p15, 0, \tmp, c3, c0, 0
str \tmp, [sp, #SVC_DACR]
#define DACR(x...) x
#else
#define DACR(x...)
#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
ldr \tmp1, [\tsk, #TI_ADDR_LIMIT]
mov \tmp2, #TASK_SIZE
str \tmp2, [\tsk, #TI_ADDR_LIMIT]
DACR( mrc p15, 0, \tmp0, c3, c0, 0)
DACR( str \tmp0, [sp, #SVC_DACR])
str \tmp1, [sp, #SVC_ADDR_LIMIT]
.if \disable
uaccess_disable \tmp0
.endif
@ -99,8 +92,11 @@
/* Restore the user access state previously saved by uaccess_entry */
.macro uaccess_exit, tsk, tmp0, tmp1
ldr \tmp1, [sp, #SVC_ADDR_LIMIT]
uaccess_restore
DACR( ldr \tmp0, [sp, #SVC_DACR])
str \tmp1, [\tsk, #TI_ADDR_LIMIT]
DACR( mcr p15, 0, \tmp0, c3, c0, 0)
.endm
#undef DACR
#endif /* __ASM_UACCESS_ASM_H__ */