sh: Initial consolidation of the _32/_64 uaccess split.

This consolidates everything but the bare assembly routines, which we
will sync up in a follow-up patch.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

include/asm-sh/uaccess.h

@@ -1,12 +1,171 @@
 #ifndef __ASM_SH_UACCESS_H
 #define __ASM_SH_UACCESS_H
 
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <asm/segment.h>
+
+#define VERIFY_READ    0
+#define VERIFY_WRITE   1
+
+#define __addr_ok(addr) \
+	((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg)
+
+/*
+ * __access_ok: Check if address with size is OK or not.
+ *
+ * Uhhuh, this needs 33-bit arithmetic. We have a carry..
+ *
+ * sum := addr + size;  carry? --> flag = true;
+ * if (sum >= addr_limit) flag = true;
+ */
+#define __access_ok(addr, size)		\
+	(__addr_ok((addr) + (size)))
+#define access_ok(type, addr, size)	\
+	(__chk_user_ptr(addr),		\
+	 __access_ok((unsigned long __force)(addr), (size)))
+
+/*
+ * Uh, these should become the main single-value transfer routines ...
+ * They automatically use the right size if we just have the right
+ * pointer type ...
+ *
+ * As SuperH uses the same address space for kernel and user data, we
+ * can just do these as direct assignments.
+ *
+ * Careful to not
+ * (a) re-use the arguments for side effects (sizeof is ok)
+ * (b) require any knowledge of processes at this stage
+ */
+#define put_user(x,ptr)		__put_user_check((x), (ptr), sizeof(*(ptr)))
+#define get_user(x,ptr)		__get_user_check((x), (ptr), sizeof(*(ptr)))
+
+/*
+ * The "__xxx" versions do not do address space checking, useful when
+ * doing multiple accesses to the same area (the user has to do the
+ * checks by hand with "access_ok()")
+ */
+#define __put_user(x,ptr)	__put_user_nocheck((x), (ptr), sizeof(*(ptr)))
+#define __get_user(x,ptr)	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
+
+struct __large_struct { unsigned long buf[100]; };
+#define __m(x) (*(struct __large_struct __user *)(x))
+
+#define __get_user_nocheck(x,ptr,size)				\
+({								\
+	long __gu_err;						\
+	unsigned long __gu_val;					\
+	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
+	__chk_user_ptr(ptr);					\
+	__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
+	(x) = (__typeof__(*(ptr)))__gu_val;			\
+	__gu_err;						\
+})
+
+#define __get_user_check(x,ptr,size)					\
+({									\
+	long __gu_err = -EFAULT;					\
+	unsigned long __gu_val = 0;					\
+	const __typeof__(*(ptr)) *__gu_addr = (ptr);			\
+	if (likely(access_ok(VERIFY_READ, __gu_addr, (size))))		\
+		__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
+	(x) = (__typeof__(*(ptr)))__gu_val;				\
+	__gu_err;							\
+})
+
+#define __put_user_nocheck(x,ptr,size)				\
+({								\
+	long __pu_err;						\
+	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
+	__chk_user_ptr(ptr);					\
+	__put_user_size((x), __pu_addr, (size), __pu_err);	\
+	__pu_err;						\
+})
+
+#define __put_user_check(x,ptr,size)				\
+({								\
+	long __pu_err = -EFAULT;				\
+	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
+	if (likely(access_ok(VERIFY_WRITE, __pu_addr, size)))	\
+		__put_user_size((x), __pu_addr, (size),		\
+				__pu_err);			\
+	__pu_err;						\
+})
+
 #ifdef CONFIG_SUPERH32
 # include "uaccess_32.h"
 #else
 # include "uaccess_64.h"
 #endif
 
+/* Generic arbitrary sized copy.  */
+/* Return the number of bytes NOT copied */
+__kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
+
+static __always_inline unsigned long
+__copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+	return __copy_user(to, (__force void *)from, n);
+}
+
+static __always_inline unsigned long __must_check
+__copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+	return __copy_user((__force void *)to, from, n);
+}
+
+#define __copy_to_user_inatomic __copy_to_user
+#define __copy_from_user_inatomic __copy_from_user
+
+/*
+ * Clear the area and return remaining number of bytes
+ * (on failure.  Usually it's 0.)
+ */
+__kernel_size_t __clear_user(void *addr, __kernel_size_t size);
+
+#define clear_user(addr,n)						\
+({									\
+	void __user * __cl_addr = (addr);				\
+	unsigned long __cl_size = (n);					\
+									\
+	if (__cl_size && access_ok(VERIFY_WRITE,			\
+		((unsigned long)(__cl_addr)), __cl_size))		\
+		__cl_size = __clear_user(__cl_addr, __cl_size);		\
+									\
+	__cl_size;							\
+})
+
+/**
+ * strncpy_from_user: - Copy a NUL terminated string from userspace.
+ * @dst:   Destination address, in kernel space.  This buffer must be at
+ *         least @count bytes long.
+ * @src:   Source address, in user space.
+ * @count: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Copies a NUL-terminated string from userspace to kernel space.
+ *
+ * On success, returns the length of the string (not including the trailing
+ * NUL).
+ *
+ * If access to userspace fails, returns -EFAULT (some data may have been
+ * copied).
+ *
+ * If @count is smaller than the length of the string, copies @count bytes
+ * and returns @count.
+ */
+#define strncpy_from_user(dest,src,count)				\
+({									\
+	unsigned long __sfu_src = (unsigned long)(src);			\
+	int __sfu_count = (int)(count);					\
+	long __sfu_res = -EFAULT;					\
+									\
+	if (__access_ok(__sfu_src, __sfu_count))			\
+		__sfu_res = __strncpy_from_user((unsigned long)(dest),	\
+				__sfu_src, __sfu_count);		\
+									\
+	__sfu_res;							\
+})
+
 static inline unsigned long
 copy_from_user(void *to, const void __user *from, unsigned long n)
 {
@@ -31,4 +190,67 @@ copy_to_user(void __user *to, const void *from, unsigned long n)
 	return __copy_size;
 }
 
+/**
+ * strnlen_user: - Get the size of a string in user space.
+ * @s: The string to measure.
+ * @n: The maximum valid length
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Get the size of a NUL-terminated string in user space.
+ *
+ * Returns the size of the string INCLUDING the terminating NUL.
+ * On exception, returns 0.
+ * If the string is too long, returns a value greater than @n.
+ */
+static inline long strnlen_user(const char __user *s, long n)
+{
+	if (!__addr_ok(s))
+		return 0;
+	else
+		return __strnlen_user(s, n);
+}
+
+/**
+ * strlen_user: - Get the size of a string in user space.
+ * @str: The string to measure.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Get the size of a NUL-terminated string in user space.
+ *
+ * Returns the size of the string INCLUDING the terminating NUL.
+ * On exception, returns 0.
+ *
+ * If there is a limit on the length of a valid string, you may wish to
+ * consider using strnlen_user() instead.
+ */
+#define strlen_user(str)	strnlen_user(str, ~0UL >> 1)
+
+/*
+ * The exception table consists of pairs of addresses: the first is the
+ * address of an instruction that is allowed to fault, and the second is
+ * the address at which the program should continue.  No registers are
+ * modified, so it is entirely up to the continuation code to figure out
+ * what to do.
+ *
+ * All the routines below use bits of fixup code that are out of line
+ * with the main instruction path.  This means when everything is well,
+ * we don't even have to jump over them.  Further, they do not intrude
+ * on our cache or tlb entries.
+ */
+struct exception_table_entry {
+	unsigned long insn, fixup;
+};
+
+#if defined(CONFIG_SUPERH64) && defined(CONFIG_MMU)
+#define ARCH_HAS_SEARCH_EXTABLE
+#endif
+
+int fixup_exception(struct pt_regs *regs);
+/* Returns 0 if exception not found and fixup.unit otherwise.  */
+unsigned long search_exception_table(unsigned long addr);
+const struct exception_table_entry *search_exception_tables(unsigned long addr);
+
+
 #endif /* __ASM_SH_UACCESS_H */