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') 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 From 2d2d255467d4ea927fbf606c8b584512edee0f7b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 7 Sep 2020 07:58:20 +0200 Subject: asm-generic: add nommu implementations of __{get,put}_kernel_nofault Add native implementations of __{get,put}_kernel_nofault using {get,put}_unaligned, just like the {get,put}_user implementations. Signed-off-by: Christoph Hellwig Acked-by: Arnd Bergmann Signed-off-by: Palmer Dabbelt --- include/asm-generic/uaccess.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/asm-generic') diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index 6de5f524e9e6..b367f339be1a 100644 --- a/include/asm-generic/uaccess.h +++ b/include/asm-generic/uaccess.h @@ -61,6 +61,22 @@ static inline int __put_user_fn(size_t size, void __user *to, void *from) } #define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k) +#define __get_kernel_nofault(dst, src, type, err_label) \ +do { \ + *((type *)dst) = get_unaligned((type *)(src)); \ + if (0) /* make sure the label looks used to the compiler */ \ + goto err_label; \ +} while (0) + +#define __put_kernel_nofault(dst, src, type, err_label) \ +do { \ + put_unaligned(*((type *)src), (type *)(dst)); \ + if (0) /* make sure the label looks used to the compiler */ \ + goto err_label; \ +} while (0) + +#define HAVE_GET_KERNEL_NOFAULT 1 + static inline __must_check unsigned long raw_copy_from_user(void *to, const void __user * from, unsigned long n) { -- cgit v1.2.3 From 3c57fa13f6bf3906643034c57736c778ce63fa55 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 7 Sep 2020 07:58:21 +0200 Subject: asm-generic: make the set_fs implementation optional Put all the set_fs related code under CONFIG_SET_FS so that asm-generic/uaccess.h can be used for set_fs-less builds. Signed-off-by: Christoph Hellwig Acked-by: Arnd Bergmann Signed-off-by: Palmer Dabbelt --- include/asm-generic/uaccess.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/asm-generic') diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index b367f339be1a..45f9872fd747 100644 --- a/include/asm-generic/uaccess.h +++ b/include/asm-generic/uaccess.h @@ -94,6 +94,7 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n) #define INLINE_COPY_TO_USER #endif /* CONFIG_UACCESS_MEMCPY */ +#ifdef CONFIG_SET_FS #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) #ifndef KERNEL_DS @@ -116,6 +117,7 @@ static inline void set_fs(mm_segment_t fs) #ifndef uaccess_kernel #define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) #endif +#endif /* CONFIG_SET_FS */ #define access_ok(addr, size) __access_ok((unsigned long)(addr),(size)) -- cgit v1.2.3