From: Andi Kleen <a...@linux.intel.com> Add a inlined __ variant of copy_from_user_nmi. The inlined variant allows the user to:
- batch the access_ok check for multiple accesses - avoid having a pagefault_disable/enable on every access if the caller already ensures disabled page faults due to its context. - get all the optimizations in copy_*_user for small constant sized transfers It is just a define to __copy_from_user_inatomic. Signed-off-by: Andi Kleen <a...@linux.intel.com> --- arch/x86/include/asm/uaccess.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index a8df874..1d0766c 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -745,5 +745,14 @@ copy_to_user(void __user *to, const void *from, unsigned long n) #undef __copy_from_user_overflow #undef __copy_to_user_overflow +/* + * We rely on the nested NMI work to allow atomic faults from the NMI path; the + * nested NMI paths are careful to preserve CR2. + * + * Caller must use pagefault_enable/disable, or run in interrupt context, + * and also do a uaccess_ok() check + */ +#define __copy_from_user_nmi __copy_from_user_inatomic + #endif /* _ASM_X86_UACCESS_H */ -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
