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From: Mark Rutland <mark.rutland@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: mark.rutland@arm.com, catalin.marinas@arm.com,
	robin.murphy@arm.com, james.morse@arm.com, will@kernel.org,
	hch@lst.de
Subject: [PATCH 08/13] arm64: uaccess: refactor __{get,put}_user
Date: Fri, 25 Sep 2020 17:07:17 +0100	[thread overview]
Message-ID: <20200925160722.27155-9-mark.rutland@arm.com> (raw)
In-Reply-To: <20200925160722.27155-1-mark.rutland@arm.com>

As a step towards implementing __{get,put}_kernel_nofault(), this patch
splits most user-memory specific logic out of __{get,put}_user(), with
the memory access and fault handling in new __{raw_get,put}_mem()
helpers.

For now the LDR/LDTR patching is left within the *get_mem() helpers, and
will be removed in a subsequent patch.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
---
 arch/arm64/include/asm/uaccess.h | 40 +++++++++++++++++++++++++---------------
 1 file changed, 25 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index d6a4e496ebc64..4ad2990241d78 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -253,7 +253,7 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
  * The "__xxx_error" versions set the third argument to -EFAULT if an error
  * occurs, and leave it unchanged on success.
  */
-#define __get_user_asm(instr, alt_instr, reg, x, addr, err, feature)	\
+#define __get_mem_asm(instr, alt_instr, reg, x, addr, err, feature)	\
 	asm volatile(							\
 	"1:"ALTERNATIVE(instr "     " reg "1, [%2]\n",			\
 			alt_instr " " reg "1, [%2]\n", feature)		\
@@ -268,35 +268,40 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
 	: "+r" (err), "=&r" (x)						\
 	: "r" (addr), "i" (-EFAULT))
 
-#define __raw_get_user(x, ptr, err)					\
+#define __raw_get_mem(x, ptr, err)					\
 do {									\
 	unsigned long __gu_val;						\
 	__chk_user_ptr(ptr);						\
-	uaccess_enable_not_uao();					\
 	switch (sizeof(*(ptr))) {					\
 	case 1:								\
-		__get_user_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr),  \
+		__get_mem_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr),	\
 			       (err), ARM64_HAS_UAO);			\
 		break;							\
 	case 2:								\
-		__get_user_asm("ldrh", "ldtrh", "%w", __gu_val, (ptr),  \
+		__get_mem_asm("ldrh", "ldtrh", "%w", __gu_val, (ptr),	\
 			       (err), ARM64_HAS_UAO);			\
 		break;							\
 	case 4:								\
-		__get_user_asm("ldr", "ldtr", "%w", __gu_val, (ptr),	\
+		__get_mem_asm("ldr", "ldtr", "%w", __gu_val, (ptr),	\
 			       (err), ARM64_HAS_UAO);			\
 		break;							\
 	case 8:								\
-		__get_user_asm("ldr", "ldtr", "%x",  __gu_val, (ptr),	\
+		__get_mem_asm("ldr", "ldtr", "%x",  __gu_val, (ptr),	\
 			       (err), ARM64_HAS_UAO);			\
 		break;							\
 	default:							\
 		BUILD_BUG();						\
 	}								\
-	uaccess_disable_not_uao();					\
 	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
 } while (0)
 
+#define __raw_get_user(x, ptr, err)					\
+do {									\
+	uaccess_enable_not_uao();					\
+	__raw_get_mem(x, ptr, err);					\
+	uaccess_disable_not_uao();					\
+} while (0)
+
 #define __get_user_error(x, ptr, err)					\
 do {									\
 	__typeof__(*(ptr)) __user *__p = (ptr);				\
@@ -318,7 +323,7 @@ do {									\
 
 #define get_user	__get_user
 
-#define __put_user_asm(instr, alt_instr, reg, x, addr, err, feature)	\
+#define __put_mem_asm(instr, alt_instr, reg, x, addr, err, feature)	\
 	asm volatile(							\
 	"1:"ALTERNATIVE(instr "     " reg "1, [%2]\n",			\
 			alt_instr " " reg "1, [%2]\n", feature)		\
@@ -332,31 +337,36 @@ do {									\
 	: "+r" (err)							\
 	: "r" (x), "r" (addr), "i" (-EFAULT))
 
-#define __raw_put_user(x, ptr, err)					\
+#define __raw_put_mem(x, ptr, err)					\
 do {									\
 	__typeof__(*(ptr)) __pu_val = (x);				\
 	__chk_user_ptr(ptr);						\
-	uaccess_enable_not_uao();					\
 	switch (sizeof(*(ptr))) {					\
 	case 1:								\
-		__put_user_asm("strb", "sttrb", "%w", __pu_val, (ptr),	\
+		__put_mem_asm("strb", "sttrb", "%w", __pu_val, (ptr),	\
 			       (err), ARM64_HAS_UAO);			\
 		break;							\
 	case 2:								\
-		__put_user_asm("strh", "sttrh", "%w", __pu_val, (ptr),	\
+		__put_mem_asm("strh", "sttrh", "%w", __pu_val, (ptr),	\
 			       (err), ARM64_HAS_UAO);			\
 		break;							\
 	case 4:								\
-		__put_user_asm("str", "sttr", "%w", __pu_val, (ptr),	\
+		__put_mem_asm("str", "sttr", "%w", __pu_val, (ptr),	\
 			       (err), ARM64_HAS_UAO);			\
 		break;							\
 	case 8:								\
-		__put_user_asm("str", "sttr", "%x", __pu_val, (ptr),	\
+		__put_mem_asm("str", "sttr", "%x", __pu_val, (ptr),	\
 			       (err), ARM64_HAS_UAO);			\
 		break;							\
 	default:							\
 		BUILD_BUG();						\
 	}								\
+} while (0)
+
+#define __raw_put_user(x, ptr, err)					\
+do {									\
+	uaccess_enable_not_uao();					\
+	__raw_put_mem(x, ptr, err);					\
 	uaccess_disable_not_uao();					\
 } while (0)
 
-- 
2.11.0


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  parent reply	other threads:[~2020-09-25 16:10 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-25 16:07 [PATCH 00/13] arm64: remove set_fs() and friends Mark Rutland
2020-09-25 16:07 ` [PATCH 01/13] arm64: head.S: rename el2_setup -> init_kernel_el Mark Rutland
2020-09-25 16:07 ` [PATCH 02/13] arm64: head.S: cleanup SCTLR_ELx initialization Mark Rutland
2020-09-25 16:07 ` [PATCH 03/13] arm64: head.S: always initialize PSTATE Mark Rutland
2020-09-30 16:09   ` James Morse
2020-10-01 11:01     ` Mark Rutland
2020-09-25 16:07 ` [PATCH 04/13] arm64: sdei: move uaccess logic to arch/arm64/ Mark Rutland
2020-09-25 16:07 ` [PATCH 05/13] arm64: uaccess: move uao_* alternatives to asm-uaccess.h Mark Rutland
2020-09-25 16:07 ` [PATCH 06/13] arm64: uaccess: rename privileged uaccess routines Mark Rutland
2020-09-25 16:07 ` [PATCH 07/13] arm64: uaccess: simplify __copy_user_flushcache() Mark Rutland
2020-09-25 16:07 ` Mark Rutland [this message]
2020-09-25 16:07 ` [PATCH 09/13] arm64: uaccess: split user/kernel routines Mark Rutland
2020-09-25 16:07 ` [PATCH 10/13] arm64: uaccess cleanup macro naming Mark Rutland
2020-09-25 16:07 ` [PATCH 11/13] arm64: uaccess: remove set_fs() Mark Rutland
2020-09-28  7:04   ` Christoph Hellwig
2020-09-28  9:02     ` Mark Rutland
2020-09-28 15:29       ` Mark Rutland
2020-09-25 16:07 ` [PATCH 12/13] arm64: uaccess: remove addr_limit_user_check() Mark Rutland
2020-09-28  7:05   ` Christoph Hellwig
2020-09-28  9:06     ` Mark Rutland
2020-09-25 16:07 ` [PATCH 13/13] arm64: uaccess: remove redundant PAN toggling Mark Rutland
2020-09-28  7:16 ` [PATCH 00/13] arm64: remove set_fs() and friends Christoph Hellwig
2020-09-28  7:23   ` Christoph Hellwig
2020-09-28  9:18     ` Mark Rutland

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