Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[deliverable/linux.git] / arch / x86 / include / asm / uaccess_64.h

diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index 8e796fbbf9c66e439418dd84580e855a173b4a12..d8def8b3dba0b46a9d52b06d65262560a8c3cca2 100644 (file)
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -17,6 +17,8 @@
 
 /* Handles exceptions in both to and from, but doesn't do access_ok */
 __must_check unsigned long
+copy_user_enhanced_fast_string(void *to, const void *from, unsigned len);
+__must_check unsigned long
 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);
@@ -26,9 +28,16 @@ copy_user_generic(void *to, const void *from, unsigned len)
 {
        unsigned ret;
 
-       alternative_call(copy_user_generic_unrolled,
+       /*
+        * If CPU has ERMS feature, use copy_user_enhanced_fast_string.
+        * Otherwise, if CPU has rep_good feature, use copy_user_generic_string.
+        * Otherwise, use copy_user_generic_unrolled.
+        */
+       alternative_call_2(copy_user_generic_unrolled,
                         copy_user_generic_string,
                         X86_FEATURE_REP_GOOD,
+                        copy_user_enhanced_fast_string,
+                        X86_FEATURE_ERMS,
                         ASM_OUTPUT2("=a" (ret), "=D" (to), "=S" (from),
                                     "=d" (len)),
                         "1" (to), "2" (from), "3" (len)