Commit c4ed0d73 authored by Tong Tiangen's avatar Tong Tiangen Committed by Will Deacon
Browse files

arm64: extable: make uaaccess helper use extable type EX_TYPE_UACCESS_ERR_ZERO 



Currnetly, the extable type used by __arch_copy_from/to_user() is
EX_TYPE_FIXUP. In fact, It is more clearly to use meaningful
EX_TYPE_UACCESS_*.

Suggested-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarTong Tiangen <tongtiangen@huawei.com>
Link: https://lore.kernel.org/r/20220621072638.1273594-5-tongtiangen@huawei.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 59e8a1ce

arch/arm64/include/asm/asm-extable.h

+8 −0
Original line number Diff line number Diff line
@@ -63,6 +63,14 @@ 
	_ASM_EXTABLE(\insn, \fixup)

	.endm



/*

 * Create an exception table entry for uaccess `insn`, which will branch to `fixup`

 * when an unhandled fault is taken.

 */

	.macro          _asm_extable_uaccess, insn, fixup

	_ASM_EXTABLE_UACCESS(\insn, \fixup)

	.endm



/*

 * Create an exception table entry for `insn` if `fixup` is provided. Otherwise

 * do nothing.

arch/arm64/include/asm/asm-uaccess.h

+6 −6
Original line number Diff line number Diff line
@@ -61,7 +61,7 @@ alternative_else_nop_endif 


#define USER(l, x...)				\

9999:	x;					\

	_asm_extable	9999b, l

	_asm_extable_uaccess	9999b, l



/*

 * Generate the assembly for LDTR/STTR with exception table entries.
@@ -73,8 +73,8 @@ alternative_else_nop_endif 
8889:		ldtr	\reg2, [\addr, #8];

		add	\addr, \addr, \post_inc;



		_asm_extable	8888b,\l;

		_asm_extable	8889b,\l;

		_asm_extable_uaccess	8888b, \l;

		_asm_extable_uaccess	8889b, \l;

	.endm



	.macro user_stp l, reg1, reg2, addr, post_inc
@@ -82,14 +82,14 @@ alternative_else_nop_endif 
8889:		sttr	\reg2, [\addr, #8];

		add	\addr, \addr, \post_inc;



		_asm_extable	8888b,\l;

		_asm_extable	8889b,\l;

		_asm_extable_uaccess	8888b,\l;

		_asm_extable_uaccess	8889b,\l;

	.endm



	.macro user_ldst l, inst, reg, addr, post_inc

8888:		\inst		\reg, [\addr];

		add		\addr, \addr, \post_inc;



		_asm_extable	8888b,\l;

		_asm_extable_uaccess	8888b, \l;

	.endm

#endif