ARM: 7527/1: uaccess: explicitly check __user pointer when !CPU_USE_DOMAINS
The {get,put}_user macros don't perform range checking on the provided
__user address when !CPU_HAS_DOMAINS.
This patch reworks the out-of-line assembly accessors to check the user
address against a specified limit, returning -EFAULT if is is out of
range.
[will: changed get_user register allocation to match put_user]
[rmk: fixed building on older ARM architectures]
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 479a635..6f83ad6 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -101,28 +101,39 @@
extern int __get_user_2(void *);
extern int __get_user_4(void *);
-#define __get_user_x(__r2,__p,__e,__s,__i...) \
+#define __GUP_CLOBBER_1 "lr", "cc"
+#ifdef CONFIG_CPU_USE_DOMAINS
+#define __GUP_CLOBBER_2 "ip", "lr", "cc"
+#else
+#define __GUP_CLOBBER_2 "lr", "cc"
+#endif
+#define __GUP_CLOBBER_4 "lr", "cc"
+
+#define __get_user_x(__r2,__p,__e,__l,__s) \
__asm__ __volatile__ ( \
__asmeq("%0", "r0") __asmeq("%1", "r2") \
+ __asmeq("%3", "r1") \
"bl __get_user_" #__s \
: "=&r" (__e), "=r" (__r2) \
- : "0" (__p) \
- : __i, "cc")
+ : "0" (__p), "r" (__l) \
+ : __GUP_CLOBBER_##__s)
#define get_user(x,p) \
({ \
+ unsigned long __limit = current_thread_info()->addr_limit - 1; \
register const typeof(*(p)) __user *__p asm("r0") = (p);\
register unsigned long __r2 asm("r2"); \
+ register unsigned long __l asm("r1") = __limit; \
register int __e asm("r0"); \
switch (sizeof(*(__p))) { \
case 1: \
- __get_user_x(__r2, __p, __e, 1, "lr"); \
- break; \
+ __get_user_x(__r2, __p, __e, __l, 1); \
+ break; \
case 2: \
- __get_user_x(__r2, __p, __e, 2, "r3", "lr"); \
+ __get_user_x(__r2, __p, __e, __l, 2); \
break; \
case 4: \
- __get_user_x(__r2, __p, __e, 4, "lr"); \
+ __get_user_x(__r2, __p, __e, __l, 4); \
break; \
default: __e = __get_user_bad(); break; \
} \
@@ -135,31 +146,34 @@
extern int __put_user_4(void *, unsigned int);
extern int __put_user_8(void *, unsigned long long);
-#define __put_user_x(__r2,__p,__e,__s) \
+#define __put_user_x(__r2,__p,__e,__l,__s) \
__asm__ __volatile__ ( \
__asmeq("%0", "r0") __asmeq("%2", "r2") \
+ __asmeq("%3", "r1") \
"bl __put_user_" #__s \
: "=&r" (__e) \
- : "0" (__p), "r" (__r2) \
+ : "0" (__p), "r" (__r2), "r" (__l) \
: "ip", "lr", "cc")
#define put_user(x,p) \
({ \
+ unsigned long __limit = current_thread_info()->addr_limit - 1; \
register const typeof(*(p)) __r2 asm("r2") = (x); \
register const typeof(*(p)) __user *__p asm("r0") = (p);\
+ register unsigned long __l asm("r1") = __limit; \
register int __e asm("r0"); \
switch (sizeof(*(__p))) { \
case 1: \
- __put_user_x(__r2, __p, __e, 1); \
+ __put_user_x(__r2, __p, __e, __l, 1); \
break; \
case 2: \
- __put_user_x(__r2, __p, __e, 2); \
+ __put_user_x(__r2, __p, __e, __l, 2); \
break; \
case 4: \
- __put_user_x(__r2, __p, __e, 4); \
+ __put_user_x(__r2, __p, __e, __l, 4); \
break; \
case 8: \
- __put_user_x(__r2, __p, __e, 8); \
+ __put_user_x(__r2, __p, __e, __l, 8); \
break; \
default: __e = __put_user_bad(); break; \
} \