x86: Fix movq immediate operand constraints in uaccess_64.h

arch/x86/include/asm/uaccess_64.h uses wrong asm operand constraint
("ir") for movq insn. Since movq sign-extends its immediate operand,
"er" constraint should be used instead.

Attached patch changes all uses of __put_user_asm in uaccess_64.h to use
"er" when "q" insn suffix is involved.

Patch was compile tested on x86_64 with defconfig.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: stable@kernel.org

diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index 8cc687326eb80f20726852c9ba66c68837e8176a..db24b215fc50668bcf3f9da0f6757016aab7956e 100644 (file)
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -88,11 +88,11 @@ int __copy_to_user(void __user *dst, const void *src, unsigned size)
                              ret, "l", "k", "ir", 4);
                return ret;
        case 8:__put_user_asm(*(u64 *)src, (u64 __user *)dst,
-                             ret, "q", "", "ir", 8);
+                             ret, "q", "", "er", 8);
                return ret;
        case 10:
                __put_user_asm(*(u64 *)src, (u64 __user *)dst,
-                              ret, "q", "", "ir", 10);
+                              ret, "q", "", "er", 10);
                if (unlikely(ret))
                        return ret;
                asm("":::"memory");
@@ -101,12 +101,12 @@ int __copy_to_user(void __user *dst, const void *src, unsigned size)
                return ret;
        case 16:
                __put_user_asm(*(u64 *)src, (u64 __user *)dst,
-                              ret, "q", "", "ir", 16);
+                              ret, "q", "", "er", 16);
                if (unlikely(ret))
                        return ret;
                asm("":::"memory");
                __put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
-                              ret, "q", "", "ir", 8);
+                              ret, "q", "", "er", 8);
                return ret;
        default:
                return copy_user_generic((__force void *)dst, src, size);
@@ -157,7 +157,7 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
                               ret, "q", "", "=r", 8);
                if (likely(!ret))
                        __put_user_asm(tmp, (u64 __user *)dst,
-                                      ret, "q", "", "ir", 8);
+                                      ret, "q", "", "er", 8);
                return ret;
        }
        default: