[S390] Make user-copy operations run-time configurable.
Introduces a struct uaccess_ops which allows setting user-copy
operations at run-time.
Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/include/asm-s390/uaccess.h b/include/asm-s390/uaccess.h
index 0b7c0ca..39a2716 100644
--- a/include/asm-s390/uaccess.h
+++ b/include/asm-s390/uaccess.h
@@ -47,7 +47,7 @@
S390_lowcore.user_asce : S390_lowcore.kernel_asce; \
asm volatile ("lctlg 7,7,%0" : : "m" (__pto) ); \
})
-#else
+#else /* __s390x__ */
#define set_fs(x) \
({ \
unsigned long __pto; \
@@ -56,7 +56,7 @@
S390_lowcore.user_asce : S390_lowcore.kernel_asce; \
asm volatile ("lctl 7,7,%0" : : "m" (__pto) ); \
})
-#endif
+#endif /* __s390x__ */
#define segment_eq(a,b) ((a).ar4 == (b).ar4)
@@ -85,76 +85,50 @@
unsigned long insn, fixup;
};
-#ifndef __s390x__
-#define __uaccess_fixup \
- ".section .fixup,\"ax\"\n" \
- "2: lhi %0,%4\n" \
- " bras 1,3f\n" \
- " .long 1b\n" \
- "3: l 1,0(1)\n" \
- " br 1\n" \
- ".previous\n" \
- ".section __ex_table,\"a\"\n" \
- " .align 4\n" \
- " .long 0b,2b\n" \
- ".previous"
-#define __uaccess_clobber "cc", "1"
-#else /* __s390x__ */
-#define __uaccess_fixup \
- ".section .fixup,\"ax\"\n" \
- "2: lghi %0,%4\n" \
- " jg 1b\n" \
- ".previous\n" \
- ".section __ex_table,\"a\"\n" \
- " .align 8\n" \
- " .quad 0b,2b\n" \
- ".previous"
-#define __uaccess_clobber "cc"
-#endif /* __s390x__ */
+struct uaccess_ops {
+ size_t (*copy_from_user)(size_t, const void __user *, void *);
+ size_t (*copy_from_user_small)(size_t, const void __user *, void *);
+ size_t (*copy_to_user)(size_t, void __user *, const void *);
+ size_t (*copy_to_user_small)(size_t, void __user *, const void *);
+ size_t (*copy_in_user)(size_t, void __user *, const void __user *);
+ size_t (*clear_user)(size_t, void __user *);
+ size_t (*strnlen_user)(size_t, const char __user *);
+ size_t (*strncpy_from_user)(size_t, const char __user *, char *);
+ int (*futex_atomic_op)(int op, int __user *, int oparg, int *old);
+ int (*futex_atomic_cmpxchg)(int __user *, int old, int new);
+};
+
+extern struct uaccess_ops uaccess;
+extern struct uaccess_ops uaccess_std;
+
+static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
+{
+ size = uaccess.copy_to_user_small(size, ptr, x);
+ return size ? -EFAULT : size;
+}
+
+static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
+{
+ size = uaccess.copy_from_user_small(size, ptr, x);
+ return size ? -EFAULT : size;
+}
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
*/
-#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
-#define __put_user_asm(x, ptr, err) \
-({ \
- err = 0; \
- asm volatile( \
- "0: mvcs 0(%1,%2),%3,%0\n" \
- "1:\n" \
- __uaccess_fixup \
- : "+&d" (err) \
- : "d" (sizeof(*(ptr))), "a" (ptr), "Q" (x), \
- "K" (-EFAULT) \
- : __uaccess_clobber ); \
-})
-#else
-#define __put_user_asm(x, ptr, err) \
-({ \
- err = 0; \
- asm volatile( \
- "0: mvcs 0(%1,%2),0(%3),%0\n" \
- "1:\n" \
- __uaccess_fixup \
- : "+&d" (err) \
- : "d" (sizeof(*(ptr))), "a" (ptr), "a" (&(x)), \
- "K" (-EFAULT), "m" (x) \
- : __uaccess_clobber ); \
-})
-#endif
-
#define __put_user(x, ptr) \
({ \
__typeof__(*(ptr)) __x = (x); \
- int __pu_err; \
+ int __pu_err = -EFAULT; \
__chk_user_ptr(ptr); \
switch (sizeof (*(ptr))) { \
case 1: \
case 2: \
case 4: \
case 8: \
- __put_user_asm(__x, ptr, __pu_err); \
+ __pu_err = __put_user_fn(sizeof (*(ptr)), \
+ ptr, &__x); \
break; \
default: \
__put_user_bad(); \
@@ -172,60 +146,36 @@
extern int __put_user_bad(void) __attribute__((noreturn));
-#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
-#define __get_user_asm(x, ptr, err) \
-({ \
- err = 0; \
- asm volatile ( \
- "0: mvcp %O1(%2,%R1),0(%3),%0\n" \
- "1:\n" \
- __uaccess_fixup \
- : "+&d" (err), "=Q" (x) \
- : "d" (sizeof(*(ptr))), "a" (ptr), \
- "K" (-EFAULT) \
- : __uaccess_clobber ); \
-})
-#else
-#define __get_user_asm(x, ptr, err) \
-({ \
- err = 0; \
- asm volatile ( \
- "0: mvcp 0(%2,%5),0(%3),%0\n" \
- "1:\n" \
- __uaccess_fixup \
- : "+&d" (err), "=m" (x) \
- : "d" (sizeof(*(ptr))), "a" (ptr), \
- "K" (-EFAULT), "a" (&(x)) \
- : __uaccess_clobber ); \
-})
-#endif
-
#define __get_user(x, ptr) \
({ \
- int __gu_err; \
- __chk_user_ptr(ptr); \
+ int __gu_err = -EFAULT; \
+ __chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: { \
unsigned char __x; \
- __get_user_asm(__x, ptr, __gu_err); \
+ __gu_err = __get_user_fn(sizeof (*(ptr)), \
+ ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 2: { \
unsigned short __x; \
- __get_user_asm(__x, ptr, __gu_err); \
+ __gu_err = __get_user_fn(sizeof (*(ptr)), \
+ ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 4: { \
unsigned int __x; \
- __get_user_asm(__x, ptr, __gu_err); \
+ __gu_err = __get_user_fn(sizeof (*(ptr)), \
+ ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 8: { \
unsigned long long __x; \
- __get_user_asm(__x, ptr, __gu_err); \
+ __gu_err = __get_user_fn(sizeof (*(ptr)), \
+ ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
@@ -247,8 +197,6 @@
#define __put_user_unaligned __put_user
#define __get_user_unaligned __get_user
-extern long __copy_to_user_asm(const void *from, long n, void __user *to);
-
/**
* __copy_to_user: - Copy a block of data into user space, with less checking.
* @to: Destination address, in user space.
@@ -266,7 +214,10 @@
static inline unsigned long
__copy_to_user(void __user *to, const void *from, unsigned long n)
{
- return __copy_to_user_asm(from, n, to);
+ if (__builtin_constant_p(n) && (n <= 256))
+ return uaccess.copy_to_user_small(n, to, from);
+ else
+ return uaccess.copy_to_user(n, to, from);
}
#define __copy_to_user_inatomic __copy_to_user
@@ -294,8 +245,6 @@
return n;
}
-extern long __copy_from_user_asm(void *to, long n, const void __user *from);
-
/**
* __copy_from_user: - Copy a block of data from user space, with less checking.
* @to: Destination address, in kernel space.
@@ -316,7 +265,10 @@
static inline unsigned long
__copy_from_user(void *to, const void __user *from, unsigned long n)
{
- return __copy_from_user_asm(to, n, from);
+ if (__builtin_constant_p(n) && (n <= 256))
+ return uaccess.copy_from_user_small(n, from, to);
+ else
+ return uaccess.copy_from_user(n, from, to);
}
/**
@@ -346,13 +298,10 @@
return n;
}
-extern unsigned long __copy_in_user_asm(const void __user *from, long n,
- void __user *to);
-
static inline unsigned long
__copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
- return __copy_in_user_asm(from, n, to);
+ return uaccess.copy_in_user(n, to, from);
}
static inline unsigned long
@@ -360,34 +309,28 @@
{
might_sleep();
if (__access_ok(from,n) && __access_ok(to,n))
- n = __copy_in_user_asm(from, n, to);
+ n = __copy_in_user(to, from, n);
return n;
}
/*
* Copy a null terminated string from userspace.
*/
-extern long __strncpy_from_user_asm(long count, char *dst,
- const char __user *src);
-
static inline long
strncpy_from_user(char *dst, const char __user *src, long count)
{
long res = -EFAULT;
might_sleep();
if (access_ok(VERIFY_READ, src, 1))
- res = __strncpy_from_user_asm(count, dst, src);
+ res = uaccess.strncpy_from_user(count, src, dst);
return res;
}
-
-extern long __strnlen_user_asm(long count, const char __user *src);
-
static inline unsigned long
strnlen_user(const char __user * src, unsigned long n)
{
might_sleep();
- return __strnlen_user_asm(n, src);
+ return uaccess.strnlen_user(n, src);
}
/**
@@ -410,12 +353,10 @@
* Zero Userspace
*/
-extern long __clear_user_asm(void __user *to, long n);
-
static inline unsigned long
__clear_user(void __user *to, unsigned long n)
{
- return __clear_user_asm(to, n);
+ return uaccess.clear_user(n, to);
}
static inline unsigned long
@@ -423,7 +364,7 @@
{
might_sleep();
if (access_ok(VERIFY_WRITE, to, n))
- n = __clear_user_asm(to, n);
+ n = uaccess.clear_user(n, to);
return n;
}