From bd79f94758c011bdffd8d4afcfb578d169cb5e93 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 23 Apr 2019 18:38:08 +0200 Subject: asm-generic: provide entirely generic nommu uaccess Move the code to implement uaccess using memcpy or direct loads and stores to asm-generic/uaccess.h and make it selectable kconfig option. Signed-off-by: Christoph Hellwig Signed-off-by: Arnd Bergmann --- include/asm-generic/uaccess.h | 48 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) (limited to 'include') diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index aac336831204..3dcabfceb21e 100644 --- a/include/asm-generic/uaccess.h +++ b/include/asm-generic/uaccess.h @@ -9,6 +9,54 @@ */ #include +#ifdef CONFIG_UACCESS_MEMCPY +static inline __must_check unsigned long +raw_copy_from_user(void *to, const void __user * from, unsigned long n) +{ + 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; + } + } + + memcpy(to, (const void __force *)from, n); + return 0; +} + +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; + default: + break; + } + } + + memcpy((void __force *)to, from, n); + return 0; +} +#define INLINE_COPY_FROM_USER +#define INLINE_COPY_TO_USER +#endif /* CONFIG_UACCESS_MEMCPY */ + #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) #ifndef KERNEL_DS -- cgit v1.2.3