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From: Christoph Hellwig <hch@lst.de>
To: Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-arch@vger.kernel.org, linux-riscv@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 6/8] riscv: refactor __get_user and __put_user
Date: Mon,  7 Sep 2020 07:58:23 +0200	[thread overview]
Message-ID: <20200907055825.1917151-7-hch@lst.de> (raw)
In-Reply-To: <20200907055825.1917151-1-hch@lst.de>

Add new __get_user_nocheck and __put_user_nocheck that switch on the size
and call the actual inline assembly helpers, and move the uaccess enable
/ disable into the actual __get_user and __put_user.  This prepares for
natively implementing __get_kernel_nofault and __put_kernel_nofault.

Also don't bother with the deprecated register keyword for the error
return.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/riscv/include/asm/uaccess.h | 94 ++++++++++++++++++--------------
 1 file changed, 52 insertions(+), 42 deletions(-)

diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
index e8eedf22e90747..b67d1c616ec348 100644
--- a/arch/riscv/include/asm/uaccess.h
+++ b/arch/riscv/include/asm/uaccess.h
@@ -107,7 +107,6 @@ static inline int __access_ok(unsigned long addr, unsigned long size)
 do {								\
 	uintptr_t __tmp;					\
 	__typeof__(x) __x;					\
-	__enable_user_access();					\
 	__asm__ __volatile__ (					\
 		"1:\n"						\
 		"	" insn " %1, %3\n"			\
@@ -125,7 +124,6 @@ do {								\
 		"	.previous"				\
 		: "+r" (err), "=&r" (__x), "=r" (__tmp)		\
 		: "m" (*(ptr)), "i" (-EFAULT));			\
-	__disable_user_access();				\
 	(x) = __x;						\
 } while (0)
 
@@ -138,7 +136,6 @@ do {								\
 	u32 __user *__ptr = (u32 __user *)(ptr);		\
 	u32 __lo, __hi;						\
 	uintptr_t __tmp;					\
-	__enable_user_access();					\
 	__asm__ __volatile__ (					\
 		"1:\n"						\
 		"	lw %1, %4\n"				\
@@ -162,12 +159,30 @@ do {								\
 			"=r" (__tmp)				\
 		: "m" (__ptr[__LSW]), "m" (__ptr[__MSW]),	\
 			"i" (-EFAULT));				\
-	__disable_user_access();				\
 	(x) = (__typeof__(x))((__typeof__((x)-(x)))(		\
 		(((u64)__hi << 32) | __lo)));			\
 } while (0)
 #endif /* CONFIG_64BIT */
 
+#define __get_user_nocheck(x, __gu_ptr, __gu_err)		\
+do {								\
+	switch (sizeof(*__gu_ptr)) {				\
+	case 1:							\
+		__get_user_asm("lb", (x), __gu_ptr, __gu_err);	\
+		break;						\
+	case 2:							\
+		__get_user_asm("lh", (x), __gu_ptr, __gu_err);	\
+		break;						\
+	case 4:							\
+		__get_user_asm("lw", (x), __gu_ptr, __gu_err);	\
+		break;						\
+	case 8:							\
+		__get_user_8((x), __gu_ptr, __gu_err);	\
+		break;						\
+	default:						\
+		BUILD_BUG();					\
+	}							\
+} while (0)
 
 /**
  * __get_user: - Get a simple variable from user space, with less checking.
@@ -191,25 +206,15 @@ do {								\
  */
 #define __get_user(x, ptr)					\
 ({								\
-	register long __gu_err = 0;				\
 	const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);	\
+	long __gu_err = 0;					\
+								\
 	__chk_user_ptr(__gu_ptr);				\
-	switch (sizeof(*__gu_ptr)) {				\
-	case 1:							\
-		__get_user_asm("lb", (x), __gu_ptr, __gu_err);	\
-		break;						\
-	case 2:							\
-		__get_user_asm("lh", (x), __gu_ptr, __gu_err);	\
-		break;						\
-	case 4:							\
-		__get_user_asm("lw", (x), __gu_ptr, __gu_err);	\
-		break;						\
-	case 8:							\
-		__get_user_8((x), __gu_ptr, __gu_err);	\
-		break;						\
-	default:						\
-		BUILD_BUG();					\
-	}							\
+								\
+	__enable_user_access();					\
+	__get_user_nocheck(x, __gu_ptr, __gu_err);		\
+	__disable_user_access();				\
+								\
 	__gu_err;						\
 })
 
@@ -243,7 +248,6 @@ do {								\
 do {								\
 	uintptr_t __tmp;					\
 	__typeof__(*(ptr)) __x = x;				\
-	__enable_user_access();					\
 	__asm__ __volatile__ (					\
 		"1:\n"						\
 		"	" insn " %z3, %2\n"			\
@@ -260,7 +264,6 @@ do {								\
 		"	.previous"				\
 		: "+r" (err), "=r" (__tmp), "=m" (*(ptr))	\
 		: "rJ" (__x), "i" (-EFAULT));			\
-	__disable_user_access();				\
 } while (0)
 
 #ifdef CONFIG_64BIT
@@ -272,7 +275,6 @@ do {								\
 	u32 __user *__ptr = (u32 __user *)(ptr);		\
 	u64 __x = (__typeof__((x)-(x)))(x);			\
 	uintptr_t __tmp;					\
-	__enable_user_access();					\
 	__asm__ __volatile__ (					\
 		"1:\n"						\
 		"	sw %z4, %2\n"				\
@@ -294,10 +296,28 @@ do {								\
 			"=m" (__ptr[__LSW]),			\
 			"=m" (__ptr[__MSW])			\
 		: "rJ" (__x), "rJ" (__x >> 32), "i" (-EFAULT));	\
-	__disable_user_access();				\
 } while (0)
 #endif /* CONFIG_64BIT */
 
+#define __put_user_nocheck(x, __gu_ptr, __pu_err)					\
+do {								\
+	switch (sizeof(*__gu_ptr)) {				\
+	case 1:							\
+		__put_user_asm("sb", (x), __gu_ptr, __pu_err);	\
+		break;						\
+	case 2:							\
+		__put_user_asm("sh", (x), __gu_ptr, __pu_err);	\
+		break;						\
+	case 4:							\
+		__put_user_asm("sw", (x), __gu_ptr, __pu_err);	\
+		break;						\
+	case 8:							\
+		__put_user_8((x), __gu_ptr, __pu_err);	\
+		break;						\
+	default:						\
+		BUILD_BUG();					\
+	}							\
+} while (0)
 
 /**
  * __put_user: - Write a simple value into user space, with less checking.
@@ -320,25 +340,15 @@ do {								\
  */
 #define __put_user(x, ptr)					\
 ({								\
-	register long __pu_err = 0;				\
 	__typeof__(*(ptr)) __user *__gu_ptr = (ptr);		\
+	long __pu_err = 0;					\
+								\
 	__chk_user_ptr(__gu_ptr);				\
-	switch (sizeof(*__gu_ptr)) {				\
-	case 1:							\
-		__put_user_asm("sb", (x), __gu_ptr, __pu_err);	\
-		break;						\
-	case 2:							\
-		__put_user_asm("sh", (x), __gu_ptr, __pu_err);	\
-		break;						\
-	case 4:							\
-		__put_user_asm("sw", (x), __gu_ptr, __pu_err);	\
-		break;						\
-	case 8:							\
-		__put_user_8((x), __gu_ptr, __pu_err);	\
-		break;						\
-	default:						\
-		BUILD_BUG();					\
-	}							\
+								\
+	__enable_user_access();					\
+	__put_user_nocheck(x, __gu_ptr, __pu_err);		\
+	__disable_user_access();				\
+								\
 	__pu_err;						\
 })
 
-- 
2.28.0


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  parent reply	other threads:[~2020-09-07  5:58 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-07  5:58 remove set_fs for riscv v2 Christoph Hellwig
2020-09-07  5:58 ` [PATCH 1/8] uaccess: provide a generic TASK_SIZE_MAX definition Christoph Hellwig
2020-09-07  5:58 ` [PATCH 2/8] asm-generic: improve the nommu {get,put}_user handling Christoph Hellwig
2020-09-07  5:58 ` [PATCH 3/8] asm-generic: add nommu implementations of __{get, put}_kernel_nofault Christoph Hellwig
2020-09-07  5:58 ` [PATCH 4/8] asm-generic: make the set_fs implementation optional Christoph Hellwig
2020-09-07  5:58 ` [PATCH 5/8] riscv: use memcpy based uaccess for nommu again Christoph Hellwig
2020-09-09  4:59   ` Palmer Dabbelt
2020-09-07  5:58 ` Christoph Hellwig [this message]
2020-09-09  4:59   ` [PATCH 6/8] riscv: refactor __get_user and __put_user Palmer Dabbelt
2020-09-07  5:58 ` [PATCH 7/8] riscv: implement __get_kernel_nofault and __put_user_nofault Christoph Hellwig
2020-09-09  4:59   ` Palmer Dabbelt
2020-09-07  5:58 ` [PATCH 8/8] riscv: remove address space overrides using set_fs() Christoph Hellwig
2020-09-09  4:59   ` Palmer Dabbelt
2020-09-09  4:59 ` remove set_fs for riscv v2 Palmer Dabbelt
2020-09-09  6:55   ` Christoph Hellwig
2020-09-09 20:38     ` Palmer Dabbelt
2020-09-22  4:37     ` Christoph Hellwig
2020-09-26 17:50       ` Palmer Dabbelt
2020-09-26 19:13         ` Arnd Bergmann
2020-10-04 17:27           ` Palmer Dabbelt
2020-09-28 12:49         ` Christoph Hellwig
2020-09-28 16:45           ` Palmer Dabbelt
2020-09-29 18:03             ` Christoph Hellwig
2020-09-26  6:58 ` Christoph Hellwig
  -- strict thread matches above, loose matches on Subject: below --
2020-09-04 16:52 remove set_fs for riscv Christoph Hellwig
2020-09-04 16:52 ` [PATCH 6/8] riscv: refactor __get_user and __put_user Christoph Hellwig

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