x86, smap: Add STAC and CLAC instructions to control user space access

[cascardo/linux.git] / arch / x86 / include / asm / futex.h

diff --git a/arch/x86/include/asm/futex.h b/arch/x86/include/asm/futex.h
index 71ecbcb..f373046 100644 (file)
--- a/arch/x86/include/asm/futex.h
+++ b/arch/x86/include/asm/futex.h
@@ -9,10 +9,13 @@
 #include <asm/asm.h>
 #include <asm/errno.h>
 #include <asm/processor.h>
+#include <asm/smap.h>
 
 #define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg)    \
-       asm volatile("1:\t" insn "\n"                           \
-                    "2:\t.section .fixup,\"ax\"\n"             \
+       asm volatile("\t" ASM_STAC "\n"                         \
+                    "1:\t" insn "\n"                           \
+                    "2:\t" ASM_CLAC "\n"                       \
+                    "\t.section .fixup,\"ax\"\n"               \
                     "3:\tmov\t%3, %1\n"                        \
                     "\tjmp\t2b\n"                              \
                     "\t.previous\n"                            \
@@ -21,12 +24,14 @@
                     : "i" (-EFAULT), "0" (oparg), "1" (0))
 
 #define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg)    \
-       asm volatile("1:\tmovl  %2, %0\n"                       \
+       asm volatile("\t" ASM_STAC "\n"                         \
+                    "1:\tmovl  %2, %0\n"                       \
                     "\tmovl\t%0, %3\n"                         \
                     "\t" insn "\n"                             \
                     "2:\t" LOCK_PREFIX "cmpxchgl %3, %2\n"     \
                     "\tjnz\t1b\n"                              \
-                    "3:\t.section .fixup,\"ax\"\n"             \
+                    "3:\t" ASM_CLAC "\n"                       \
+                    "\t.section .fixup,\"ax\"\n"               \
                     "4:\tmov\t%5, %1\n"                        \
                     "\tjmp\t3b\n"                              \
                     "\t.previous\n"                            \
@@ -122,8 +127,10 @@ static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
        if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
                return -EFAULT;
 
-       asm volatile("1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n"
-                    "2:\t.section .fixup, \"ax\"\n"
+       asm volatile("\t" ASM_STAC "\n"
+                    "1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n"
+                    "2:\t" ASM_CLAC "\n"
+                    "\t.section .fixup, \"ax\"\n"
                     "3:\tmov     %3, %0\n"
                     "\tjmp     2b\n"
                     "\t.previous\n"