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Subject[PATCH 6/8] riscv: refactor __get_user and __put_user
Date
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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