Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0fb19dcb64ec4bd9934eee26ce66417fe028ffd8
Commit:     0fb19dcb64ec4bd9934eee26ce66417fe028ffd8
Parent:     fc55888f83c1c0ac09abe4680f9a94fc0662677f
Author:     Stuart Menefy <[EMAIL PROTECTED]>
AuthorDate: Fri Nov 30 18:16:23 2007 +0900
Committer:  Paul Mundt <[EMAIL PROTECTED]>
CommitDate: Mon Jan 28 13:18:59 2008 +0900

    sh: get_user fixes and nommu consolidation.
    
    When a get_user(to, from++) is called the pointer increment is performed
    after its first usage, in the specific after the __add_ok invokation.
    This causes a wrong get_user return value, putting a wrong character
    in the destination variable. This patch solves the problem using a new
    temporary pointer.
    
    Additionally this reworks the use of the register banks, allowing for
    consolidation between the MMU and nommu implementations.
    
    Signed-off-by: Carmelo Amoroso <[EMAIL PROTECTED]>
    Signed-off-by: Giuseppe Condorelli <[EMAIL PROTECTED]>
    Signed-off-by: Stuart Menefy <[EMAIL PROTECTED]>
    Signed-off-by: Paul Mundt <[EMAIL PROTECTED]>
---
 include/asm-sh/uaccess_32.h |  253 +++++++++++++++++--------------------------
 1 files changed, 98 insertions(+), 155 deletions(-)

diff --git a/include/asm-sh/uaccess_32.h b/include/asm-sh/uaccess_32.h
index f18a1a5..59a9f20 100644
--- a/include/asm-sh/uaccess_32.h
+++ b/include/asm-sh/uaccess_32.h
@@ -73,37 +73,24 @@ static inline int __access_ok(unsigned long addr, unsigned 
long size)
 /*
  * __access_ok: Check if address with size is OK or not.
  *
- * We do three checks:
- * (1) is it user space?
- * (2) addr + size --> carry?
- * (3) addr + size >= 0x80000000  (PAGE_OFFSET)
+ * Uhhuh, this needs 33-bit arithmetic. We have a carry..
  *
- * (1) (2) (3) | RESULT
- *  0   0   0  |  ok
- *  0   0   1  |  ok
- *  0   1   0  |  bad
- *  0   1   1  |  bad
- *  1   0   0  |  ok
- *  1   0   1  |  bad
- *  1   1   0  |  bad
- *  1   1   1  |  bad
+ * sum := addr + size;  carry? --> flag = true;
+ * if (sum >= addr_limit) flag = true;
  */
 static inline int __access_ok(unsigned long addr, unsigned long size)
 {
-       unsigned long flag, tmp;
-
-       __asm__("stc    r7_bank, %0\n\t"
-               "mov.l  @(8,%0), %0\n\t"
-               "clrt\n\t"
-               "addc   %2, %1\n\t"
-               "and    %1, %0\n\t"
-               "rotcl  %0\n\t"
-               "rotcl  %0\n\t"
-               "and    #3, %0"
-               : "=&z" (flag), "=r" (tmp)
-               : "r" (addr), "1" (size)
-               : "t");
-
+       unsigned long flag, sum;
+
+       __asm__("clrt\n\t"
+               "addc   %3, %1\n\t"
+               "movt   %0\n\t"
+               "cmp/hi %4, %1\n\t"
+               "rotcl  %0"
+               :"=&r" (flag), "=r" (sum)
+               :"1" (addr), "r" (size),
+                "r" (current_thread_info()->addr_limit.seg)
+               :"t");
        return flag == 0;
 }
 #endif /* CONFIG_MMU */
@@ -165,135 +152,47 @@ do {                                                     
        \
 #define __get_user_nocheck(x,ptr,size)                         \
 ({                                                             \
        long __gu_err, __gu_val;                                \
-       __get_user_size(__gu_val, (ptr), (size), __gu_err);     \
+       __typeof__(*(ptr)) *__pu_addr = (ptr);  \
+       __get_user_size(__gu_val, (__pu_addr), (size), __gu_err);       \
        (x) = (__typeof__(*(ptr)))__gu_val;                     \
        __gu_err;                                               \
 })
 
-#ifdef CONFIG_MMU
-#define __get_user_check(x,ptr,size)                           \
-({                                                             \
-       long __gu_err, __gu_val;                                \
-       __chk_user_ptr(ptr);                                    \
-       switch (size) {                                         \
-       case 1:                                                 \
-               __get_user_1(__gu_val, (ptr), __gu_err);        \
-               break;                                          \
-       case 2:                                                 \
-               __get_user_2(__gu_val, (ptr), __gu_err);        \
-               break;                                          \
-       case 4:                                                 \
-               __get_user_4(__gu_val, (ptr), __gu_err);        \
-               break;                                          \
-       default:                                                \
-               __get_user_unknown();                           \
-               break;                                          \
-       }                                                       \
-                                                               \
-       (x) = (__typeof__(*(ptr)))__gu_val;                     \
-       __gu_err;                                               \
-})
-
-#define __get_user_1(x,addr,err) ({            \
-__asm__("stc   r7_bank, %1\n\t"                \
-       "mov.l  @(8,%1), %1\n\t"                \
-       "and    %2, %1\n\t"                     \
-       "cmp/pz %1\n\t"                         \
-       "bt/s   1f\n\t"                         \
-       " mov   #0, %0\n\t"                     \
-       "0:\n"                                  \
-       "mov    #-14, %0\n\t"                   \
-       "bra    2f\n\t"                         \
-       " mov   #0, %1\n"                       \
-       "1:\n\t"                                \
-       "mov.b  @%2, %1\n\t"                    \
-       "extu.b %1, %1\n"                       \
-       "2:\n"                                  \
-       ".section       __ex_table,\"a\"\n\t"   \
-       ".long  1b, 0b\n\t"                     \
-       ".previous"                             \
-       : "=&r" (err), "=&r" (x)                \
-       : "r" (addr)                            \
-       : "t");                                 \
-})
-
-#define __get_user_2(x,addr,err) ({            \
-__asm__("stc   r7_bank, %1\n\t"                \
-       "mov.l  @(8,%1), %1\n\t"                \
-       "and    %2, %1\n\t"                     \
-       "cmp/pz %1\n\t"                         \
-       "bt/s   1f\n\t"                         \
-       " mov   #0, %0\n\t"                     \
-       "0:\n"                                  \
-       "mov    #-14, %0\n\t"                   \
-       "bra    2f\n\t"                         \
-       " mov   #0, %1\n"                       \
-       "1:\n\t"                                \
-       "mov.w  @%2, %1\n\t"                    \
-       "extu.w %1, %1\n"                       \
-       "2:\n"                                  \
-       ".section       __ex_table,\"a\"\n\t"   \
-       ".long  1b, 0b\n\t"                     \
-       ".previous"                             \
-       : "=&r" (err), "=&r" (x)                \
-       : "r" (addr)                            \
-       : "t");                                 \
-})
-
-#define __get_user_4(x,addr,err) ({            \
-__asm__("stc   r7_bank, %1\n\t"                \
-       "mov.l  @(8,%1), %1\n\t"                \
-       "and    %2, %1\n\t"                     \
-       "cmp/pz %1\n\t"                         \
-       "bt/s   1f\n\t"                         \
-       " mov   #0, %0\n\t"                     \
-       "0:\n"                                  \
-       "mov    #-14, %0\n\t"                   \
-       "bra    2f\n\t"                         \
-       " mov   #0, %1\n"                       \
-       "1:\n\t"                                \
-       "mov.l  @%2, %1\n\t"                    \
-       "2:\n"                                  \
-       ".section       __ex_table,\"a\"\n\t"   \
-       ".long  1b, 0b\n\t"                     \
-       ".previous"                             \
-       : "=&r" (err), "=&r" (x)                \
-       : "r" (addr)                            \
-       : "t");                                 \
-})
-#else /* CONFIG_MMU */
 #define __get_user_check(x,ptr,size)                                   \
 ({                                                                     \
        long __gu_err, __gu_val;                                        \
-       if (__access_ok((unsigned long)(ptr), (size))) {                \
-               __get_user_size(__gu_val, (ptr), (size), __gu_err);     \
-               (x) = (__typeof__(*(ptr)))__gu_val;                     \
-       } else                                                          \
+       __typeof__(*(ptr)) *__pu_addr = (ptr);                          \
+       __chk_user_ptr(__pu_addr);                                      \
+       if (likely(__addr_ok((unsigned long)(__pu_addr)))) {            \
+               __get_user_size(__gu_val, (__pu_addr), (size), __gu_err);\
+       } else {                                                        \
                __gu_err = -EFAULT;                                     \
+               __gu_val = 0;                                           \
+       }                                                               \
+       (x) = (__typeof__(*(ptr)))__gu_val;                             \
        __gu_err;                                                       \
 })
-#endif
 
 #define __get_user_asm(x, addr, err, insn) \
 ({ \
 __asm__ __volatile__( \
        "1:\n\t" \
        "mov." insn "   %2, %1\n\t" \
-       "mov    #0, %0\n" \
        "2:\n" \
        ".section       .fixup,\"ax\"\n" \
        "3:\n\t" \
        "mov    #0, %1\n\t" \
        "mov.l  4f, %0\n\t" \
        "jmp    @%0\n\t" \
-       " mov   %3, %0\n" \
+       " mov   %3, %0\n\t" \
+       ".balign        4\n" \
        "4:     .long   2b\n\t" \
        ".previous\n" \
        ".section       __ex_table,\"a\"\n\t" \
        ".long  1b, 3b\n\t" \
        ".previous" \
        :"=&r" (err), "=&r" (x) \
-       :"m" (__m(addr)), "i" (-EFAULT)); })
+       :"m" (__m(addr)), "i" (-EFAULT), "0" (err)); })
 
 extern void __get_user_unknown(void);
 
@@ -328,11 +227,13 @@ do {                                                      
\
 
 #define __put_user_check(x,ptr,size)                           \
 ({                                                             \
-       long __pu_err = -EFAULT;                                \
+       long __pu_err;                                          \
        __typeof__(*(ptr)) __user *__pu_addr = (ptr);           \
                                                                \
-       if (__access_ok((unsigned long)__pu_addr,size))         \
+       if (likely(__addr_ok((unsigned long)__pu_addr)))        \
                __put_user_size((x),__pu_addr,(size),__pu_err); \
+       else                                                    \
+               __pu_err = -EFAULT;                             \
        __pu_err;                                               \
 })
 
@@ -341,45 +242,43 @@ do {                                                      
\
 __asm__ __volatile__( \
        "1:\n\t" \
        "mov." insn "   %1, %2\n\t" \
-       "mov    #0, %0\n" \
        "2:\n" \
        ".section       .fixup,\"ax\"\n" \
        "3:\n\t" \
-       "nop\n\t" \
        "mov.l  4f, %0\n\t" \
        "jmp    @%0\n\t" \
-       "mov    %3, %0\n" \
+       " mov   %3, %0\n\t" \
+       ".balign        4\n" \
        "4:     .long   2b\n\t" \
        ".previous\n" \
        ".section       __ex_table,\"a\"\n\t" \
        ".long  1b, 3b\n\t" \
        ".previous" \
        :"=&r" (err) \
-       :"r" (x), "m" (__m(addr)), "i" (-EFAULT) \
+       :"r" (x), "m" (__m(addr)), "i" (-EFAULT), "0" (err)     \
         :"memory"); })
 
-#if defined(__LITTLE_ENDIAN__)
+#if defined(CONFIG_CPU_LITTLE_ENDIAN)
 #define __put_user_u64(val,addr,retval) \
 ({ \
 __asm__ __volatile__( \
        "1:\n\t" \
        "mov.l  %R1,%2\n\t" \
        "mov.l  %S1,%T2\n\t" \
-       "mov    #0,%0\n" \
        "2:\n" \
        ".section       .fixup,\"ax\"\n" \
        "3:\n\t" \
-       "nop\n\t" \
        "mov.l  4f,%0\n\t" \
        "jmp    @%0\n\t" \
-       " mov   %3,%0\n" \
+       " mov   %3,%0\n\t" \
+       ".balign        4\n" \
        "4:     .long   2b\n\t" \
        ".previous\n" \
        ".section       __ex_table,\"a\"\n\t" \
        ".long  1b, 3b\n\t" \
        ".previous" \
        : "=r" (retval) \
-       : "r" (val), "m" (__m(addr)), "i" (-EFAULT) \
+       : "r" (val), "m" (__m(addr)), "i" (-EFAULT), "0" (retval) \
         : "memory"); })
 #else
 #define __put_user_u64(val,addr,retval) \
@@ -388,21 +287,20 @@ __asm__ __volatile__( \
        "1:\n\t" \
        "mov.l  %S1,%2\n\t" \
        "mov.l  %R1,%T2\n\t" \
-       "mov    #0,%0\n" \
        "2:\n" \
        ".section       .fixup,\"ax\"\n" \
        "3:\n\t" \
-       "nop\n\t" \
        "mov.l  4f,%0\n\t" \
        "jmp    @%0\n\t" \
-       " mov   %3,%0\n" \
+       " mov   %3,%0\n\t" \
+       ".balign        4\n" \
        "4:     .long   2b\n\t" \
        ".previous\n" \
        ".section       __ex_table,\"a\"\n\t" \
        ".long  1b, 3b\n\t" \
        ".previous" \
        : "=r" (retval) \
-       : "r" (val), "m" (__m(addr)), "i" (-EFAULT) \
+       : "r" (val), "m" (__m(addr)), "i" (-EFAULT), "0" (retval) \
         : "memory"); })
 #endif
 
@@ -463,7 +361,7 @@ static __inline__ int
 __strncpy_from_user(unsigned long __dest, unsigned long __user __src, int 
__count)
 {
        __kernel_size_t res;
-       unsigned long __dummy, _d, _s;
+       unsigned long __dummy, _d, _s, _c;
 
        __asm__ __volatile__(
                "9:\n"
@@ -472,17 +370,17 @@ __strncpy_from_user(unsigned long __dest, unsigned long 
__user __src, int __coun
                "bt/s   2f\n"
                "1:\n"
                "mov.b  %1, @%3\n\t"
-               "dt     %7\n\t"
+               "dt     %4\n\t"
                "bf/s   9b\n\t"
                " add   #1, %3\n\t"
                "2:\n\t"
-               "sub    %7, %0\n"
+               "sub    %4, %0\n"
                "3:\n"
                ".section .fixup,\"ax\"\n"
                "4:\n\t"
                "mov.l  5f, %1\n\t"
                "jmp    @%1\n\t"
-               " mov   %8, %0\n\t"
+               " mov   %9, %0\n\t"
                ".balign 4\n"
                "5:     .long 3b\n"
                ".previous\n"
@@ -490,14 +388,32 @@ __strncpy_from_user(unsigned long __dest, unsigned long 
__user __src, int __coun
                "       .balign 4\n"
                "       .long 9b,4b\n"
                ".previous"
-               : "=r" (res), "=&z" (__dummy), "=r" (_s), "=r" (_d)
-               : "0" (__count), "2" (__src), "3" (__dest), "r" (__count),
+               : "=r" (res), "=&z" (__dummy), "=r" (_s), "=r" (_d), "=r"(_c)
+               : "0" (__count), "2" (__src), "3" (__dest), "4" (__count),
                  "i" (-EFAULT)
                : "memory", "t");
 
        return res;
 }
 
+/**
+ * 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); \
@@ -507,7 +423,8 @@ __sfu_res = __strncpy_from_user((unsigned long) (dest), 
__sfu_src, __sfu_count);
 } __sfu_res; })
 
 /*
- * Return the size of a string (including the ending 0!)
+ * Return the size of a string (including the ending 0 even when we have
+ * exceeded the maximum string length).
  */
 static __inline__ long __strnlen_user(const char __user *__s, long __n)
 {
@@ -515,14 +432,13 @@ static __inline__ long __strnlen_user(const char __user 
*__s, long __n)
        unsigned long __dummy;
 
        __asm__ __volatile__(
-               "9:\n"
-               "cmp/eq %4, %0\n\t"
-               "bt     2f\n"
                "1:\t"
                "mov.b  @(%0,%3), %1\n\t"
+               "cmp/eq %4, %0\n\t"
+               "bt/s   2f\n\t"
+               " add   #1, %0\n\t"
                "tst    %1, %1\n\t"
-               "bf/s   9b\n\t"
-               " add   #1, %0\n"
+               "bf     1b\n\t"
                "2:\n"
                ".section .fixup,\"ax\"\n"
                "3:\n\t"
@@ -542,6 +458,19 @@ static __inline__ long __strnlen_user(const char __user 
*__s, long __n)
        return res;
 }
 
+/**
+ * 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))
@@ -550,6 +479,20 @@ static __inline__ long strnlen_user(const char __user *s, 
long n)
                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)
 
 /*
-
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