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: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
[will: tweaked commit message and changed temporary variable names]
Signed-off-by: Will Deacon <will@kernel.org>

5 files changed, 5 insertions, 13 deletions

diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S
index 322b55664cca..aeafc03e961a 100644
--- a/arch/arm64/lib/clear_user.S
+++ b/arch/arm64/lib/clear_user.S
@@ -20,7 +20,6 @@
  * Alignment fixed up by hardware.
  */
 ENTRY(__arch_clear_user)
-	uaccess_enable_not_uao x2, x3, x4
 	mov	x2, x1			// save the size for fixup return
 	subs	x1, x1, #8
 	b.mi	2f
@@ -40,7 +39,6 @@ uao_user_alternative 9f, strh, sttrh, wzr, x0, 2
 	b.mi	5f
 uao_user_alternative 9f, strb, sttrb, wzr, x0, 0
 5:	mov	x0, #0
-	uaccess_disable_not_uao x2, x3
 	ret
 ENDPROC(__arch_clear_user)
 EXPORT_SYMBOL(__arch_clear_user)
@@ -48,6 +46,5 @@ EXPORT_SYMBOL(__arch_clear_user)
 	.section .fixup,"ax"
 	.align	2
 9:	mov	x0, x2			// return the original size
-	uaccess_disable_not_uao x2, x3
 	ret
 	.previous
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index 8472dc7798b3..ebb3c06cbb5d 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S
@@ -54,10 +54,8 @@
 
 end	.req	x5
 ENTRY(__arch_copy_from_user)
-	uaccess_enable_not_uao x3, x4, x5
 	add	end, x0, x2
 #include "copy_template.S"
-	uaccess_disable_not_uao x3, x4
 	mov	x0, #0				// Nothing to copy
 	ret
 ENDPROC(__arch_copy_from_user)
@@ -66,6 +64,5 @@ EXPORT_SYMBOL(__arch_copy_from_user)
 	.section .fixup,"ax"
 	.align	2
 9998:	sub	x0, end, dst			// bytes not copied
-	uaccess_disable_not_uao x3, x4
 	ret
 	.previous
diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
index 8e0355c1e318..3d8153a1ebce 100644
--- a/arch/arm64/lib/copy_in_user.S
+++ b/arch/arm64/lib/copy_in_user.S
@@ -56,10 +56,8 @@
 end	.req	x5
 
 ENTRY(__arch_copy_in_user)
-	uaccess_enable_not_uao x3, x4, x5
 	add	end, x0, x2
 #include "copy_template.S"
-	uaccess_disable_not_uao x3, x4
 	mov	x0, #0
 	ret
 ENDPROC(__arch_copy_in_user)
@@ -68,6 +66,5 @@ EXPORT_SYMBOL(__arch_copy_in_user)
 	.section .fixup,"ax"
 	.align	2
 9998:	sub	x0, end, dst			// bytes not copied
-	uaccess_disable_not_uao x3, x4
 	ret
 	.previous
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index 6085214654dc..357eae2c18eb 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S
@@ -53,10 +53,8 @@
 
 end	.req	x5
 ENTRY(__arch_copy_to_user)
-	uaccess_enable_not_uao x3, x4, x5
 	add	end, x0, x2
 #include "copy_template.S"
-	uaccess_disable_not_uao x3, x4
 	mov	x0, #0
 	ret
 ENDPROC(__arch_copy_to_user)
@@ -65,6 +63,5 @@ EXPORT_SYMBOL(__arch_copy_to_user)
 	.section .fixup,"ax"
 	.align	2
 9998:	sub	x0, end, dst			// bytes not copied
-	uaccess_disable_not_uao x3, x4
 	ret
 	.previous
diff --git a/arch/arm64/lib/uaccess_flushcache.c b/arch/arm64/lib/uaccess_flushcache.c
index cbfcbe6470a5..bfa30b75b2b8 100644
--- a/arch/arm64/lib/uaccess_flushcache.c
+++ b/arch/arm64/lib/uaccess_flushcache.c
@@ -28,7 +28,11 @@ void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
 unsigned long __copy_user_flushcache(void *to, const void __user *from,
 				     unsigned long n)
 {
-	unsigned long rc = __arch_copy_from_user(to, from, n);
+	unsigned long rc;
+
+	uaccess_enable_not_uao();
+	rc = __arch_copy_from_user(to, from, n);
+	uaccess_disable_not_uao();
 
 	/* See above */
 	__clean_dcache_area_pop(to, n - rc);