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Subject[PATCH 13/27] asm-generic: make uaccess.h usable by mmu archs
Make it possible to override some functions from uaccess.h
so that architectures with an mmu can provide assembly
versions of the functions with their own fixup logic.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
include/asm-generic/uaccess.h | 102 +++++++++++++++++++++++++---------------
1 files changed, 64 insertions(+), 38 deletions(-)

diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index ebeacd9..e05f6a9 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -31,14 +31,14 @@ static inline void set_fs(mm_segment_t fs)
#define VERIFY_READ 0
#define VERIFY_WRITE 1

-#define access_ok(type, addr, size) _access_ok((unsigned long)(addr),(size))
+#define access_ok(type, addr, size) __access_ok((unsigned long)(addr),(size))

/*
* The architecture should really override this if possible, at least
* doing a check on the get_fs()
*/
-#ifndef _access_ok
-static inline int _access_ok(unsigned long addr, unsigned long size)
+#ifndef __access_ok
+static inline int __access_ok(unsigned long addr, unsigned long size)
{
return 1;
}
@@ -93,7 +93,7 @@ extern int __put_user_bad(void);
#endif

#define put_user(x, ptr) ( \
- access_ok(VERIFY_WRITE, ptr, sizeof (*ptr)) ? \
+ __access_ok(ptr, sizeof (*ptr)) ? \
__put_user(x, ptr) : \
-EFAULT)

@@ -120,45 +120,62 @@ extern int __get_user_bad(void);
#endif

#define get_user(x, ptr) ( \
- access_ok(VERIFY_READ, ptr, sizeof (*ptr)) ? \
+ __access_ok(ptr, sizeof (*ptr)) ? \
__get_user(x, ptr) : \
-EFAULT)

-#define __copy_from_user(to, from, n) (memcpy(to, from, n), 0)
-#define __copy_to_user(to, from, n) (memcpy(to, from, n), 0)
-#define __copy_to_user_inatomic __copy_to_user
-#define __copy_from_user_inatomic __copy_from_user
+#ifndef __copy_from_user
+static inline __must_check long __copy_from_user(void *to,
+ const void __user *from, unsigned long n)
+{
+ memcpy(to, (const void __force *)from, n);
+ return 0;
+}
+#endif

-#define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
+#ifndef __copy_to_user
+static inline __must_check long __copy_to_user(void __user *to,
+ const void *from, unsigned long n)
+{
+ memcpy((void __force *)to, from, n);
+ return 0;
+}
+#endif
+
+#ifndef __copy_from_user_inatomic
+#define __copy_from_user_inatomic __copy_from_user
+#endif

-#define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
+#ifndef __copy_to_user_inatomic
+#define __copy_to_user_inatomic __copy_to_user
+#endif

static inline long copy_from_user(void *to,
- const void __user * from, unsigned long n)
+ const void __user * from, unsigned long n)
{
- if (access_ok(VERIFY_READ, from, n))
- __copy_from_user(to, from, n);
+ might_sleep();
+ if (__access_ok(from, n))
+ return __copy_from_user(to, from, n);
else
return n;
- return 0;
}

-static inline long copy_to_user(void *to,
- const void __user * from, unsigned long n)
+static inline long copy_to_user(void __user *to,
+ const void *from, unsigned long n)
{
- if (access_ok(VERIFY_WRITE, to, n))
- __copy_to_user(to, from, n);
+ might_sleep();
+ if (__access_ok(to, n))
+ return __copy_to_user(to, from, n);
else
return n;
- return 0;
}

/*
* Copy a null terminated string from userspace.
*/
-
+#ifndef __strncpy_from_user
static inline long
-__do_strncpy_from_user(char *dst, const char __user *src, long count)
+__strncpy_from_user(char *dst, const char __user *src, long count)
{
char *tmp;
strncpy(dst, src, count);
@@ -166,19 +183,14 @@ __do_strncpy_from_user(char *dst, const char __user *src, long count)
;
return (tmp - dst);
}
+#endif

static inline long
strncpy_from_user(char *dst, const char __user *src, long count)
{
- if (!access_ok(VERIFY_READ, src, 1))
+ if (!__access_ok(src, 1))
return -EFAULT;
- return __do_strncpy_from_user(dst, src, count);
-}
-
-static inline long
-__strncpy_from_user(char *dst, const char __user *src, long count)
-{
- return __do_strncpy_from_user(dst, src, count);
+ return __strncpy_from_user(dst, src, count);
}

/*
@@ -186,24 +198,38 @@ __strncpy_from_user(char *dst, const char __user *src, long count)
*
* Return 0 on exception, a value greater than N if too long
*/
-static inline long strnlen_user(const char *src, long n)
+#ifndef strnlen_user
+static inline long strnlen_user(const char __user *src, long n)
{
- return strlen(src) + 1;
+ return strlen((void * __force)src) + 1;
}
+#endif

-#define strlen_user(str) strnlen_user(str, 32767)
+static inline long strlen_user(const char __user *src)
+{
+ return strnlen_user(src, 32767);
+}

/*
* Zero Userspace
*/
-
-static inline unsigned long
-__clear_user(void *to, unsigned long n)
+#ifndef __clear_user
+static inline __must_check unsigned long
+__clear_user(void __user *to, unsigned long n)
{
- memset(to, 0, n);
+ memset((void __force *)to, 0, n);
return 0;
}
+#endif

-#define clear_user(to, n) __clear_user(to, n)
+static inline __must_check unsigned long
+clear_user(void __user *to, unsigned long n)
+{
+ might_sleep();
+ if (!__access_ok(to, n))
+ return n;
+
+ return __clear_user(to, n);
+}

#endif /* __ASM_GENERIC_UACCESS_H */
--
1.5.6.3



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