Commit e50be648 authored by Pavel Tatashin's avatar Pavel Tatashin Committed by Will Deacon
Browse files

arm64: uaccess: Remove uaccess_*_not_uao asm macros 



It is safer and simpler to drop the uaccess assembly macros in favour of
inline C functions. Although this bloats the Image size slightly, it
aligns our user copy routines with '{get,put}_user()' and generally
makes the code a lot easier to reason about.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: default avatarMark Rutland <mark.rutland@arm.com>
Tested-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarPavel Tatashin <pasha.tatashin@soleen.com>
[will: tweaked commit message and changed temporary variable names]
Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 94bb804e

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

+0 −17
Original line number Original line Diff line number Diff line
@@ -58,23 +58,6 @@ alternative_else_nop_endif 
	.endm

	.endm

#endif

#endif





/*

 * These macros are no-ops when UAO is present.

 */

	.macro	uaccess_disable_not_uao, tmp1, tmp2

	uaccess_ttbr0_disable \tmp1, \tmp2

alternative_if ARM64_ALT_PAN_NOT_UAO

	SET_PSTATE_PAN(1)

alternative_else_nop_endif

	.endm



	.macro	uaccess_enable_not_uao, tmp1, tmp2, tmp3

	uaccess_ttbr0_enable \tmp1, \tmp2, \tmp3

alternative_if ARM64_ALT_PAN_NOT_UAO

	SET_PSTATE_PAN(0)

alternative_else_nop_endif

	.endm



/*

/*

 * Remove the address tag from a virtual address, if present.

 * Remove the address tag from a virtual address, if present.

 */

 */

arch/arm64/include/asm/uaccess.h

+22 −5
Original line number Original line Diff line number Diff line
@@ -378,20 +378,34 @@ do { \ 
extern unsigned long __must_check __arch_copy_from_user(void *to, const void __user *from, unsigned long n);

extern unsigned long __must_check __arch_copy_from_user(void *to, const void __user *from, unsigned long n);

#define raw_copy_from_user(to, from, n)					\

#define raw_copy_from_user(to, from, n)					\

({									\

({									\

	__arch_copy_from_user((to), __uaccess_mask_ptr(from), (n));	\

	unsigned long __acfu_ret;					\

	uaccess_enable_not_uao();					\

	__acfu_ret = __arch_copy_from_user((to),			\

				      __uaccess_mask_ptr(from), (n));	\

	uaccess_disable_not_uao();					\

	__acfu_ret;							\

})

})





extern unsigned long __must_check __arch_copy_to_user(void __user *to, const void *from, unsigned long n);

extern unsigned long __must_check __arch_copy_to_user(void __user *to, const void *from, unsigned long n);

#define raw_copy_to_user(to, from, n)					\

#define raw_copy_to_user(to, from, n)					\

({									\

({									\

	__arch_copy_to_user(__uaccess_mask_ptr(to), (from), (n));	\

	unsigned long __actu_ret;					\

	uaccess_enable_not_uao();					\

	__actu_ret = __arch_copy_to_user(__uaccess_mask_ptr(to),	\

				    (from), (n));			\

	uaccess_disable_not_uao();					\

	__actu_ret;							\

})

})





extern unsigned long __must_check __arch_copy_in_user(void __user *to, const void __user *from, unsigned long n);

extern unsigned long __must_check __arch_copy_in_user(void __user *to, const void __user *from, unsigned long n);

#define raw_copy_in_user(to, from, n)					\

#define raw_copy_in_user(to, from, n)					\

({									\

({									\

	__arch_copy_in_user(__uaccess_mask_ptr(to),			\

	unsigned long __aciu_ret;					\

	uaccess_enable_not_uao();					\

	__aciu_ret = __arch_copy_in_user(__uaccess_mask_ptr(to),	\

				    __uaccess_mask_ptr(from), (n));	\

				    __uaccess_mask_ptr(from), (n));	\

	uaccess_disable_not_uao();					\

	__aciu_ret;							\

})

})





#define INLINE_COPY_TO_USER

#define INLINE_COPY_TO_USER
@@ -400,8 +414,11 @@ extern unsigned long __must_check __arch_copy_in_user(void __user *to, const voi 
extern unsigned long __must_check __arch_clear_user(void __user *to, unsigned long n);

extern unsigned long __must_check __arch_clear_user(void __user *to, unsigned long n);

static inline unsigned long __must_check __clear_user(void __user *to, unsigned long n)

static inline unsigned long __must_check __clear_user(void __user *to, unsigned long n)

{

{

	if (access_ok(to, n))

	if (access_ok(to, n)) {

		uaccess_enable_not_uao();

		n = __arch_clear_user(__uaccess_mask_ptr(to), n);

		n = __arch_clear_user(__uaccess_mask_ptr(to), n);

		uaccess_disable_not_uao();

	}

	return n;

	return n;

}

}

#define clear_user	__clear_user

#define clear_user	__clear_user

arch/arm64/lib/clear_user.S

+0 −3
Original line number Original line Diff line number Diff line
@@ -20,7 +20,6 @@ 
 * Alignment fixed up by hardware.

 * Alignment fixed up by hardware.

 */

 */

ENTRY(__arch_clear_user)

ENTRY(__arch_clear_user)

	uaccess_enable_not_uao x2, x3, x4

	mov	x2, x1			// save the size for fixup return

	mov	x2, x1			// save the size for fixup return

	subs	x1, x1, #8

	subs	x1, x1, #8

	b.mi	2f

	b.mi	2f
@@ -40,7 +39,6 @@ uao_user_alternative 9f, strh, sttrh, wzr, x0, 2 
	b.mi	5f

	b.mi	5f

uao_user_alternative 9f, strb, sttrb, wzr, x0, 0

uao_user_alternative 9f, strb, sttrb, wzr, x0, 0

5:	mov	x0, #0

5:	mov	x0, #0

	uaccess_disable_not_uao x2, x3

	ret

	ret

ENDPROC(__arch_clear_user)

ENDPROC(__arch_clear_user)

EXPORT_SYMBOL(__arch_clear_user)

EXPORT_SYMBOL(__arch_clear_user)
@@ -48,6 +46,5 @@ EXPORT_SYMBOL(__arch_clear_user) 
	.section .fixup,"ax"

	.section .fixup,"ax"

	.align	2

	.align	2

9:	mov	x0, x2			// return the original size

9:	mov	x0, x2			// return the original size

	uaccess_disable_not_uao x2, x3

	ret

	ret

	.previous
 
	.previous

arch/arm64/lib/copy_from_user.S

+0 −3
Original line number Original line Diff line number Diff line
@@ -54,10 +54,8 @@ 




end	.req	x5

end	.req	x5

ENTRY(__arch_copy_from_user)

ENTRY(__arch_copy_from_user)

	uaccess_enable_not_uao x3, x4, x5

	add	end, x0, x2

	add	end, x0, x2

#include "copy_template.S"

#include "copy_template.S"

	uaccess_disable_not_uao x3, x4

	mov	x0, #0				// Nothing to copy

	mov	x0, #0				// Nothing to copy

	ret

	ret

ENDPROC(__arch_copy_from_user)

ENDPROC(__arch_copy_from_user)
@@ -66,6 +64,5 @@ EXPORT_SYMBOL(__arch_copy_from_user) 
	.section .fixup,"ax"

	.section .fixup,"ax"

	.align	2

	.align	2

9998:	sub	x0, end, dst			// bytes not copied

9998:	sub	x0, end, dst			// bytes not copied

	uaccess_disable_not_uao x3, x4

	ret

	ret

	.previous
 
	.previous

arch/arm64/lib/copy_in_user.S

+0 −3
Original line number Original line Diff line number Diff line
@@ -56,10 +56,8 @@ 
end	.req	x5

end	.req	x5





ENTRY(__arch_copy_in_user)

ENTRY(__arch_copy_in_user)

	uaccess_enable_not_uao x3, x4, x5

	add	end, x0, x2

	add	end, x0, x2

#include "copy_template.S"

#include "copy_template.S"

	uaccess_disable_not_uao x3, x4

	mov	x0, #0

	mov	x0, #0

	ret

	ret

ENDPROC(__arch_copy_in_user)

ENDPROC(__arch_copy_in_user)
@@ -68,6 +66,5 @@ EXPORT_SYMBOL(__arch_copy_in_user) 
	.section .fixup,"ax"

	.section .fixup,"ax"

	.align	2

	.align	2

9998:	sub	x0, end, dst			// bytes not copied

9998:	sub	x0, end, dst			// bytes not copied

	uaccess_disable_not_uao x3, x4

	ret

	ret

	.previous
 
	.previous

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