Merge branches 'fixes', 'misc' and 'spectre' into for-linus

[linux-2.6-microblaze.git] / arch / arm / include / asm / uaccess.h

diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 3d614e9..5451e1f 100644 (file)
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -84,6 +84,13 @@ static inline void set_fs(mm_segment_t fs)
                : "cc"); \
        flag; })
 
+/*
+ * This is a type: either unsigned long, if the argument fits into
+ * that type, or otherwise unsigned long long.
+ */
+#define __inttype(x) \
+       __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
+
 /*
  * Single-value transfer routines.  They automatically use the right
  * size if we just have the right pointer type.  Note that the functions
@@ -153,7 +160,7 @@ extern int __get_user_64t_4(void *);
        ({                                                              \
                unsigned long __limit = current_thread_info()->addr_limit - 1; \
                register typeof(*(p)) __user *__p asm("r0") = (p);      \
-               register typeof(x) __r2 asm("r2");                      \
+               register __inttype(x) __r2 asm("r2");                   \
                register unsigned long __l asm("r1") = __limit;         \
                register int __e asm("r0");                             \
                unsigned int __ua_flags = uaccess_save_and_enable();    \
@@ -243,6 +250,16 @@ static inline void set_fs(mm_segment_t fs)
 #define user_addr_max() \
        (uaccess_kernel() ? ~0UL : get_fs())
 
+#ifdef CONFIG_CPU_SPECTRE
+/*
+ * When mitigating Spectre variant 1, it is not worth fixing the non-
+ * verifying accessors, because we need to add verification of the
+ * address space there.  Force these to use the standard get_user()
+ * version instead.
+ */
+#define __get_user(x, ptr) get_user(x, ptr)
+#else
+
 /*
  * The "__xxx" versions of the user access functions do not verify the
  * address space - it must have been done previously with a separate
@@ -259,12 +276,6 @@ static inline void set_fs(mm_segment_t fs)
        __gu_err;                                                       \
 })
 
-#define __get_user_error(x, ptr, err)                                  \
-({                                                                     \
-       __get_user_err((x), (ptr), err);                                \
-       (void) 0;                                                       \
-})
-
 #define __get_user_err(x, ptr, err)                                    \
 do {                                                                   \
        unsigned long __gu_addr = (unsigned long)(ptr);                 \
@@ -324,6 +335,7 @@ do {                                                                        \
 
 #define __get_user_asm_word(x, addr, err)                      \
        __get_user_asm(x, addr, err, ldr)
+#endif
 
 
 #define __put_user_switch(x, ptr, __err, __fn)                         \