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Diffstat (limited to 'arch/x86/include/asm/uaccess_64.h')
-rw-r--r--arch/x86/include/asm/uaccess_64.h21
1 files changed, 20 insertions, 1 deletions
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index 535e421498f..316708d5af9 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -8,6 +8,8 @@
#include <linux/errno.h>
#include <linux/prefetch.h>
#include <linux/lockdep.h>
+#include <asm/alternative.h>
+#include <asm/cpufeature.h>
#include <asm/page.h>
/*
@@ -16,7 +18,24 @@
/* Handles exceptions in both to and from, but doesn't do access_ok */
__must_check unsigned long
-copy_user_generic(void *to, const void *from, unsigned len);
+copy_user_generic_string(void *to, const void *from, unsigned len);
+__must_check unsigned long
+copy_user_generic_unrolled(void *to, const void *from, unsigned len);
+
+static __always_inline __must_check unsigned long
+copy_user_generic(void *to, const void *from, unsigned len)
+{
+ unsigned ret;
+
+ alternative_call(copy_user_generic_unrolled,
+ copy_user_generic_string,
+ X86_FEATURE_REP_GOOD,
+ ASM_OUTPUT2("=a" (ret), "=D" (to), "=S" (from),
+ "=d" (len)),
+ "1" (to), "2" (from), "3" (len)
+ : "memory", "rcx", "r8", "r9", "r10", "r11");
+ return ret;
+}
__must_check unsigned long
_copy_to_user(void __user *to, const void *from, unsigned len);