Nommu architectures do not have page tables and thus no page faults. Implement the maccess helpers using get_unaligned and put_unaligned and enable them unconditionally for !CONFIG_MMU.
Signed-off-by: Christoph Hellwig <[email protected]> --- include/asm-generic/uaccess.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index ba68ee4dabfaa7..cc3b2c8b68fab4 100644 --- a/include/asm-generic/uaccess.h +++ b/include/asm-generic/uaccess.h @@ -9,6 +9,26 @@ */ #include <linux/string.h> +#ifndef CONFIG_MMU +#include <asm/unaligned.h> + +#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 +#endif /* !CONFIG_MMU */ + #ifdef CONFIG_UACCESS_MEMCPY static inline __must_check unsigned long raw_copy_from_user(void *to, const void __user * from, unsigned long n) -- 2.28.0
