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>

1 files changed, 222 insertions, 0 deletions

diff --git a/include/asm-sh/uaccess.h b/include/asm-sh/uaccess.h
index b3440c305b5d..45c2c9b2993d 100644
--- a/include/asm-sh/uaccess.h
+++ b/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 */