From 931de11f5a374748f1d620ee17810dedf13c9f69 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 7 Sep 2020 07:58:19 +0200 Subject: asm-generic: improve the nommu {get,put}_user handling Instead of reusing raw_{copy,to}_from_user implement separate handlers using {get,put}_unaligned. This ensures unaligned access is handled correctly, and avoid the need for the small constant size optimization in raw_{copy,to}_from_user. Signed-off-by: Christoph Hellwig Acked-by: Arnd Bergmann Signed-off-by: Palmer Dabbelt --- include/asm-generic/uaccess.h | 91 ++++++++++++++++++++++++------------------- 1 file changed, 51 insertions(+), 40 deletions(-) (limited to 'include/asm-generic/uaccess.h') diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index ba68ee4dabfa..6de5f524e9e6 100644 --- a/include/asm-generic/uaccess.h +++ b/include/asm-generic/uaccess.h @@ -10,28 +10,60 @@ #include #ifdef CONFIG_UACCESS_MEMCPY -static inline __must_check unsigned long -raw_copy_from_user(void *to, const void __user * from, unsigned long n) +#include + +static inline int __get_user_fn(size_t size, const void __user *from, void *to) { - if (__builtin_constant_p(n)) { - switch(n) { - case 1: - *(u8 *)to = *(u8 __force *)from; - return 0; - case 2: - *(u16 *)to = *(u16 __force *)from; - return 0; - case 4: - *(u32 *)to = *(u32 __force *)from; - return 0; -#ifdef CONFIG_64BIT - case 8: - *(u64 *)to = *(u64 __force *)from; - return 0; -#endif - } + BUILD_BUG_ON(!__builtin_constant_p(size)); + + switch (size) { + case 1: + *(u8 *)to = get_unaligned((u8 __force *)from); + return 0; + case 2: + *(u16 *)to = get_unaligned((u16 __force *)from); + return 0; + case 4: + *(u32 *)to = get_unaligned((u32 __force *)from); + return 0; + case 8: + *(u64 *)to = get_unaligned((u64 __force *)from); + return 0; + default: + BUILD_BUG(); + return 0; + } + +} +#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k) + +static inline int __put_user_fn(size_t size, void __user *to, void *from) +{ + BUILD_BUG_ON(!__builtin_constant_p(size)); + + switch (size) { + case 1: + put_unaligned(*(u8 *)from, (u8 __force *)to); + return 0; + case 2: + put_unaligned(*(u16 *)from, (u16 __force *)to); + return 0; + case 4: + put_unaligned(*(u32 *)from, (u32 __force *)to); + return 0; + case 8: + put_unaligned(*(u64 *)from, (u64 __force *)to); + return 0; + default: + BUILD_BUG(); + return 0; } +} +#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k) +static inline __must_check unsigned long +raw_copy_from_user(void *to, const void __user * from, unsigned long n) +{ memcpy(to, (const void __force *)from, n); return 0; } @@ -39,27 +71,6 @@ raw_copy_from_user(void *to, const void __user * from, unsigned long n) static inline __must_check unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) { - if (__builtin_constant_p(n)) { - switch(n) { - case 1: - *(u8 __force *)to = *(u8 *)from; - return 0; - case 2: - *(u16 __force *)to = *(u16 *)from; - return 0; - case 4: - *(u32 __force *)to = *(u32 *)from; - return 0; -#ifdef CONFIG_64BIT - case 8: - *(u64 __force *)to = *(u64 *)from; - return 0; -#endif - default: - break; - } - } - memcpy((void __force *)to, from, n); return 0; } -- cgit v1.2.3