Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit abd641e9 authored by Russell King's avatar Russell King Committed by Greg Kroah-Hartman
Browse files

ARM: uaccess: consolidate uaccess asm to asm/uaccess-asm.h 



[ Upstream commit 747ffc2fcf969eff9309d7f2d1d61cb8b9e1bb40 ]

Consolidate the user access assembly code to asm/uaccess-asm.h.  This
moves the csdb, check_uaccess, uaccess_mask_range_ptr, uaccess_enable,
uaccess_disable, uaccess_save, uaccess_restore macros, and creates two
new ones for exception entry and exit - uaccess_entry and uaccess_exit.

This makes the uaccess_save and uaccess_restore macros private to
asm/uaccess-asm.h.

Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 54f4bbd8

arch/arm/include/asm/assembler.h

+1 −74
Original line number Diff line number Diff line
@@ -21,11 +21,11 @@ 
#endif



#include <asm/ptrace.h>

#include <asm/domain.h>

#include <asm/opcodes-virt.h>

#include <asm/asm-offsets.h>

#include <asm/page.h>

#include <asm/thread_info.h>

#include <asm/uaccess-asm.h>



#define IOMEM(x)	(x)
@@ -447,79 +447,6 @@ THUMB( orr \reg , \reg , #PSR_T_BIT ) 
	.size \name , . - \name

	.endm



	.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



	.irp	c,,eq,ne,cs,cc,mi,pl,vs,vc,hi,ls,ge,lt,gt,le,hs,lo

	.macro	ret\c, reg

#if __LINUX_ARM_ARCH__ < 6

arch/arm/include/asm/uaccess-asm.h

0 → 100644
+106 −0
Original line number Diff line number Diff line 
/* 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__ */

arch/arm/kernel/entry-armv.S

+2 −9
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <asm/unistd.h>

#include <asm/tls.h>

#include <asm/system_info.h>

#include <asm/uaccess-asm.h>



#include "entry-header.S"

#include <asm/entry-macro-multi.S>
@@ -182,15 +183,7 @@ ENDPROC(__und_invalid) 
	stmia	r7, {r2 - r6}



	get_thread_info tsk

	ldr	r0, [tsk, #TI_ADDR_LIMIT]

	mov	r1, #TASK_SIZE

	str	r1, [tsk, #TI_ADDR_LIMIT]

	str	r0, [sp, #SVC_ADDR_LIMIT]



	uaccess_save r0

	.if \uaccess

	uaccess_disable r0

	.endif

	uaccess_entry tsk, r0, r1, r2, \uaccess



	.if \trace

#ifdef CONFIG_TRACE_IRQFLAGS

arch/arm/kernel/entry-header.S

+3 −6
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include <asm/asm-offsets.h>

#include <asm/errno.h>

#include <asm/thread_info.h>

#include <asm/uaccess-asm.h>

#include <asm/v7m.h>



@ Bad Abort numbers
@@ -217,9 +218,7 @@ 
	blne	trace_hardirqs_off

#endif

	.endif

	ldr	r1, [sp, #SVC_ADDR_LIMIT]

	uaccess_restore

	str	r1, [tsk, #TI_ADDR_LIMIT]

	uaccess_exit tsk, r0, r1



#ifndef CONFIG_THUMB2_KERNEL

	@ ARM mode SVC restore
@@ -263,9 +262,7 @@ 
	@ on the stack remains correct).

	@

	.macro  svc_exit_via_fiq

	ldr	r1, [sp, #SVC_ADDR_LIMIT]

	uaccess_restore

	str	r1, [tsk, #TI_ADDR_LIMIT]

	uaccess_exit tsk, r0, r1

#ifndef CONFIG_THUMB2_KERNEL

	@ ARM mode restore

	mov	r0, sp