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nios linux module unkown symbol解决

分类： 嵌入式

2012-03-29 14:34:20

如果使用nios2-linux-20100621.tar移植带mmu的linux系统，自己添加驱动程序时。编译时会出错：
"__copy_from_user" [~/mymod.ko] undefined!
或是运行insmod时出错：
insmod: can't insert 'mymod.ko': unknown symbol in module, or unknown parameter
主要是因为uaccess.c中没有对__copy_from_user进行EXPORT_SYMBOL
只要修改

linux-2.6/arch/nios2/mm/uaccess.c

linux-2.6/arch/nios2/include/asm/uaccess.h

这两个文件即可：

uaccess.c

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  1. /*
  2.  * This file is subject to the terms and conditions of the GNU General Public
  3.  * License. See the file "COPYING" in the main directory of this archive
  4.  * for more details.
  5.  *
  6.  * Copyright (C) 2009, Wind River Systems Inc
  7.  * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
  8.  */

  10. #include <asm/uaccess.h>
  11. #include <linux/module.h>

  13. extern long __copy_from_user(void *to, const void __user *from, unsigned long n);
  14. asm(" .global    __copy_from_user \n"
  15.     " .type __copy_from_user, @function \n"
  16.     "__copy_from_user: \n"
  17.     " movi r2,7 \n"
  18.     " mov r3,r4 \n"
  19.     " bge    r2,r6,1f \n"
  20.     " xor    r2,r4,r5             \n"
  21.     " andi    r2,r2,3 \n"
  22.     " movi    r7,3 \n"
  23.     " beq    r2,zero,4f \n"
  24.     "1: addi r6,r6,-1 \n"
  25.     " movi    r2,-1 \n"
  26.     " beq    r6,r2,3f \n"
  27.     " mov    r7,r2 \n"
  28.     "2: ldbu r2,0(r5) \n"
  29.     " addi    r6,r6,-1 \n"
  30.     " addi    r5,r5,1 \n"
  31.     " stb    r2,0(r3) \n"
  32.     " addi    r3,r3,1 \n"
  33.     " bne    r6,r7,2b \n"
  34.     "3: \n"
  35.     " addi r2,r6,1 \n"
  36.     " ret \n"
  37.     "13:mov r2,r6 \n"
  38.     " ret \n"
  39.     "4: andi r2,r4,1 \n"
  40.     " cmpeq    r2,r2,zero \n"
  41.     " beq    r2,zero,7f \n"
  42.     "5: andi r2,r3,2 \n"
  43.     " beq    r2,zero,6f \n"
  44.     "9: ldhu    r2,0(r5) \n"
  45.     " addi    r6,r6,-2 \n"
  46.     " addi    r5,r5,2 \n"
  47.     " sth    r2,0(r3) \n"
  48.     " addi    r3,r3,2 \n"
  49.     "6: bge r7,r6,1b \n"
  50.     "10:ldw    r2,0(r5) \n"
  51.     " addi    r6,r6,-4 \n"
  52.     " addi    r5,r5,4 \n"
  53.     " stw    r2,0(r3) \n"
  54.     " addi    r3,r3,4 \n"
  55.     " br    6b \n"
  56.     "7: ldbu r2,0(r5) \n"
  57.     " addi    r6,r6,-1 \n"
  58.     " addi    r5,r5,1 \n"
  59.     " addi    r3,r4,1 \n"
  60.     " stb    r2,0(r4) \n"
  61.     " br    5b \n"
  62.     ".section __ex_table,\"a\" \n"
  63.     ".word 2b,3b \n"
  64.     ".word 9b,13b \n"
  65.     ".word 10b,13b \n"
  66.     ".word 7b,13b \n"
  67.     ".previous \n"
  68.    );
  69. EXPORT_SYMBOL(__copy_from_user);

  71. extern long __copy_to_user(void __user *to, const void *from, unsigned long n);
  72. asm(
  73.    " .global    __copy_to_user \n"
  74.    " .type __copy_to_user, @function \n"
  75.    "__copy_to_user: \n"
  76.    " movi r2,7 \n"
  77.    " mov r3,r4 \n"
  78.    " bge    r2,r6,1f \n"
  79.    " xor    r2,r4,r5 \n"
  80.    " andi    r2,r2,3 \n"
  81.    " movi    r7,3 \n"
  82.    " beq    r2,zero,4f \n"
  83. /* Bail if we try to copy zero bytes */
  84.    "1: addi r6,r6,-1 \n"
  85.    " movi    r2,-1 \n"
  86.    " beq    r6,r2,3f \n"
  87. /* Copy byte by byte for small copies and if src^dst != 0 */
  88.    " mov    r7,r2 \n"
  89.    "2: ldbu r2,0(r5) \n"
  90.    " addi    r5,r5,1 \n"
  91.    "9: stb    r2,0(r3)            \n"
  92.    " addi    r6,r6,-1            \n"
  93.    " addi    r3,r3,1                \n"
  94.    " bne    r6,r7,2b            \n"
  95.    "3: addi r2,r6,1            \n"
  96.    " ret \n"
  97.    "13:mov r2,r6 \n"
  98.    " ret \n"
  99. /* If 'to' is an odd address byte copy */
  100.    "4: andi r2,r4,1                \n"
  101.    " cmpeq    r2,r2,zero            \n"
  102.    " beq    r2,zero,7f            \n"
  103. /* If 'to' is not divideable by four copy halfwords */
  104.    "5: andi r2,r3,2                \n"
  105.    " beq    r2,zero,6f            \n"
  106.    " ldhu    r2,0(r5)            \n"
  107.    " addi    r5,r5,2                \n"
  108.    "10:sth    r2,0(r3)            \n"
  109.    " addi    r6,r6,-2            \n"
  110.    " addi    r3,r3,2                \n"
  111. /* Copy words */
  112.    "6: bge r7,r6,1b                \n"
  113.    " ldw    r2,0(r5)            \n"
  114.    " addi    r5,r5,4                \n"
  115.    "11:stw    r2,0(r3)            \n"
  116.    " addi    r6,r6,-4            \n"
  117.    " addi    r3,r3,4                \n"
  118.    " br    6b                \n"
  119. /* Copy remaining bytes */
  120.    "7: ldbu r2,0(r5)                \n"
  121.    " addi    r5,r5,1                \n"
  122.    " addi    r3,r4,1                \n"
  123.    "12: stb    r2,0(r4)            \n"
  124.    " addi    r6,r6,-1            \n"
  125.    " br    5b                \n"
  126.    ".section __ex_table,\"a\" \n"
  127.    ".word 9b,3b     \n"
  128.    ".word 10b,13b     \n"
  129.    ".word 11b,13b     \n"
  130.    ".word 12b,13b     \n"
  131.    ".previous \n");
  132. EXPORT_SYMBOL(__copy_to_user);

  134. long strncpy_from_user(char *__to, const char __user *__from, long __len)
  135. {
  136.     int l = strnlen_user(__from, __len);
  137.     int is_zt = 1;

  139.     if (l > __len) {
  140.         is_zt = 0;
  141.         l = __len;
  142.     }

  144.     if (l == 0 || copy_from_user(__to, __from, l))
  145.         return -EFAULT;

  147.     if (is_zt)
  148.         l--;
  149.     return l;
  150. }

  152. long strnlen_user(const char __user *s, long n)
  153. {
  154.     long i;

  156.     for (i = 0; i < n; i++) {
  157.         char c;
  158.         if (get_user(c, s + i) == -EFAULT)
  159.             return 0;
  160.         if (c == 0)
  161.             return i + 1;
  162.     }
  163.     return n + 1;
  164. }

uaccess.h:

点击(此处)折叠或打开

  1. /*
  2.  * User space memory access functions for Nios II
  3.  *
  4.  * Copyright (C) 2010-2011, Tobias Klauser <tklauser@distanz.ch>
  5.  * Copyright (C) 2009, Wind River Systems Inc
  6.  * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
  7.  *
  8.  * Based on asm/uaccess.h from m68knommu
  9.  *
  10.  * This file is subject to the terms and conditions of the GNU General Public
  11.  * License. See the file "COPYING" in the main directory of this archive
  12.  * for more details.
  13.  */

  15. #ifndef _ASM_NIOS2_UACCESS_H
  16. #define _ASM_NIOS2_UACCESS_H

  18. #include <linux/errno.h>
  19. #include <linux/thread_info.h>
  20. #include <linux/string.h>

  22. #include <asm/page.h>

  24. #define VERIFY_READ 0
  25. #define VERIFY_WRITE 1

  27. /*
  28.  * The exception table consists of pairs of addresses: the first is the
  29.  * address of an instruction that is allowed to fault, and the second is
  30.  * the address at which the program should continue. No registers are
  31.  * modified, so it is entirely up to the continuation code to figure out
  32.  * what to do.
  33.  *
  34.  * All the routines below use bits of fixup code that are out of line
  35.  * with the main instruction path. This means when everything is well,
  36.  * we don't even have to jump over them. Further, they do not intrude
  37.  * on our cache or tlb entries.
  38.  */
  39. struct exception_table_entry {
  40.     unsigned long insn;
  41.     unsigned long fixup;
  42. };

  44. #ifdef CONFIG_MMU
  45. extern int fixup_exception(struct pt_regs *regs);
  46. #endif

  48. /*
  49.  * Segment stuff
  50.  */
  51. #define MAKE_MM_SEG(s)        ((mm_segment_t) { (s) } )
  52. #define USER_DS            MAKE_MM_SEG(0x80000000UL)
  53. #define KERNEL_DS        MAKE_MM_SEG(0)

  55. #define get_ds()        (KERNEL_DS)

  57. #define get_fs()        (current_thread_info()->addr_limit)
  58. #define set_fs(seg)        (current_thread_info()->addr_limit = (seg))

  60. #define segment_eq(a, b)    ((a).seg == (b).seg)

  62. #ifdef CONFIG_MMU
  63. #define __access_ok(addr, len)            \
  64.     (((signed long)(((long)get_fs().seg) &    \
  65.             ((long)(addr) | (((long)(addr)) + (len)) | (len)))) == 0)
  66. #else
  67. static inline int __access_ok(unsigned long addr, unsigned long size)
  68. {
  69.     addr &= ~CONFIG_IO_REGION_BASE;    /* ignore 'uncached' bit */
  70.     return ((addr >= CONFIG_MEM_BASE) && ((addr + size) < memory_end));
  71. }
  72. #endif /* CONFIG_MMU */

  74. #define access_ok(type, addr, len)        \
  75.     likely(__access_ok((unsigned long)(addr), (unsigned long)(len)))

  77. #ifdef CONFIG_MMU
  78. # define __EX_TABLE_SECTION    ".section __ex_table,\"a\"\n"
  79. #else
  80. # define __EX_TABLE_SECTION    ".section .discard,\"a\"\n"
  81. #endif

  83. /*
  84.  * Zero Userspace
  85.  */

  87. static inline unsigned long __must_check __clear_user(void __user *to,
  88.                          unsigned long n)
  89. {
  90.     __asm__ __volatile__ (
  91.         "1: stb zero, 0(%1)\n"
  92.         " addi %0, %0, -1\n"
  93.         " addi %1, %1, 1\n"
  94.         " bne %0, zero, 1b\n"
  95.         "2:\n"
  96.         __EX_TABLE_SECTION
  97.         ".word 1b, 2b\n"
  98.         ".previous\n"
  99.         : "=r" (n), "=r" (to)
  100.         : "0" (n), "1" (to)
  101.     );

  103.     return n;
  104. }

  106. static inline unsigned long __must_check clear_user(void __user *to,
  107.                          unsigned long n)
  108. {
  109.     if (!access_ok(VERIFY_WRITE, to, n))
  110.         return n;
  111.     return __clear_user(to, n);
  112. }

  114. #ifdef CONFIG_MMU
  115. extern long __copy_from_user(void* to, const void __user *from, unsigned long n);
  116. extern long __copy_to_user(void __user *to, const void *from, unsigned long n);

  118. static inline long copy_from_user(void *to, const void __user *from, unsigned long n)
  119. {
  120.     if (!access_ok(VERIFY_READ, from, n))
  121.         return n;
  122.     return __copy_from_user(to, from, n);
  123. }

  125. static inline long copy_to_user(void __user *to, const void *from, unsigned long n)
  126. {
  127.     if (!access_ok(VERIFY_WRITE, to, n))
  128.         return n;
  129.     return __copy_to_user(to, from, n);
  130. }

  132. extern long strncpy_from_user(char *__to, const char __user *__from,
  133.                 long __len);
  134. extern long strnlen_user(const char __user *s, long n);

  136. #else /* CONFIG_MMU */
  137. # define copy_from_user(to, from, n)    (memcpy(to, from, n), 0)
  138. # define copy_to_user(to, from, n)    (memcpy(to, from, n), 0)

  140. # define __copy_from_user(to, from, n)    copy_from_user(to, from, n)
  141. # define __copy_to_user(to, from, n)    copy_to_user(to, from, n)

  143. static inline long strncpy_from_user(char *dst, const char *src, long count)
  144. {
  145.     char *tmp;
  146.     strncpy(dst, src, count);
  147.     for (tmp = dst; *tmp && count > 0; tmp++, count--)
  148.         ;
  149.     return(tmp - dst); /* DAVIDM should we count a NUL ? check getname */
  150. }

  152. /*
  153.  * Return the size of a string (including the ending 0)
  154.  *
  155.  * Return 0 on exception, a value greater than N if too long
  156.  */
  157. static inline long strnlen_user(const char *src, long n)
  158. {
  159.     return strlen(src) + 1; /* DAVIDM make safer */
  160. }

  162. #endif /* CONFIG_MMU */

  164. #define __copy_from_user_inatomic    __copy_from_user
  165. #define __copy_to_user_inatomic        __copy_to_user

  167. /*
  168.  * TODO: get_user/put_user stuff below can probably be the same for MMU and
  169.  * NOMMU.
  170.  */

  172. #ifdef CONFIG_MMU

  174. /* Optimized macros */
  175. #define __get_user_asm(val, insn, addr, err) \
  176.    { \
  177.                                                                      \
  178.       __asm__ __volatile__( \
  179.         " movi %0, %3 \n" \
  180.         "1: " insn " %1, 0(%2) \n" \
  181.         " movi %0, 0 \n" \
  182.         "2: \n" \
  183.         " .section __ex_table,\"a\" \n" \
  184.         " .word 1b, 2b \n" \
  185.         " .previous " \
  186.         : "=&r" (err), "=r" (val) \
  187.         : "r" (addr), "i" (-EFAULT)); \
  188.    }

  190. #define __get_user_unknown(val, size, ptr, err) do { \
  191.       err = 0; \
  192.       if(copy_from_user(&(val), ptr, size)) { \
  193.          err = -EFAULT; \
  194.       } \
  195.    } while(0)

  197. #define __get_user_common(val, size, ptr, err) \
  198.    do { \
  199.       switch (size) { \
  200.          case 1: __get_user_asm(val, "ldbu", ptr, err); break; \
  201.          case 2: __get_user_asm(val, "ldhu", ptr, err); break; \
  202.          case 4: __get_user_asm(val, "ldw", ptr, err); break; \
  203.          default: __get_user_unknown(val, size, ptr, err); break; \
  204.       } \
  205.    } while (0)

  207. #define __get_user(x,ptr) \
  208.    ({ \
  209.       long __gu_err = -EFAULT; \
  210.       const __typeof__(*(ptr)) __user * __gu_ptr = (ptr); \
  211.       unsigned long __gu_val; /* FIXME: should be __typeof__ */ \
  212.       __get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err); \
  213.       (x) = (__typeof__(x))__gu_val; \
  214.       __gu_err; \
  215.    })

  217. #define get_user(x,ptr) \
  218.    ({ \
  219.       long __gu_err = -EFAULT; \
  220.       const __typeof__(*(ptr)) __user * __gu_ptr = (ptr); \
  221.       unsigned long __gu_val = 0; \
  222.       if (access_ok(VERIFY_READ, __gu_ptr, sizeof(*__gu_ptr)))        \
  223.          __get_user_common(__gu_val, sizeof(*__gu_ptr), __gu_ptr, __gu_err); \
  224.       (x) = (__typeof__(x))__gu_val; \
  225.       __gu_err; \
  226.    })

  228. #define __put_user_asm(val, insn, ptr,err) \
  229.    { \
  230.       __asm__ __volatile__( \
  231.         " movi %0, %3 \n" \
  232.         "1: " insn " %1, 0(%2) \n" \
  233.         " movi %0, 0 \n" \
  234.         "2: \n" \
  235.         " .section __ex_table,\"a\" \n" \
  236.         " .word 1b, 2b \n" \
  237.         " .previous \n" \
  238.         : "=&r" (err) \
  239.         : "r" (val), "r" (ptr), "i" (-EFAULT)); \
  240.    }

  242. #define put_user(x, ptr)                        \
  243. ({                                    \
  244.     long __pu_err = -EFAULT;                    \
  245.     __typeof__(*(ptr)) __user *__pu_ptr = (ptr);            \
  246.     __typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x);        \
  247.     if (access_ok(VERIFY_WRITE, __pu_ptr, sizeof(*__pu_ptr))) {    \
  248.         switch (sizeof(*__pu_ptr)) {                \
  249.         case 1:                            \
  250.             __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
  251.             break;                        \
  252.         case 2:                            \
  253.             __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
  254.             break;                        \
  255.         case 4:                            \
  256.             __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
  257.             break;                        \
  258.         default:                        \
  259.             /* XXX: This looks wrong... */            \
  260.             __pu_err = 0;                    \
  261.             if (copy_to_user(__pu_ptr, &(__pu_val), sizeof(*__pu_ptr))) \
  262.                 __pu_err = -EFAULT;            \
  263.             break;                        \
  264.         }                            \
  265.     }                                \
  266.     __pu_err;                            \
  267. })

  269. #define __put_user(x, ptr) put_user(x, ptr)

  271. #else /* CONFIG_MMU */

  273. /*
  274.  * These are the main single-value transfer routines. They automatically
  275.  * use the right size if we just have the right pointer type.
  276.  */

  278. #define put_user(x, ptr)                \
  279. ({                            \
  280.     int __pu_err = 0;                \
  281.     __typeof__(*(ptr)) __pu_val = (x);        \
  282.     switch (sizeof (*(ptr))) {            \
  283.     case 1:                        \
  284.     case 2:                        \
  285.     case 4:                        \
  286.     case 8:                        \
  287.         memcpy(ptr, &__pu_val, sizeof(*(ptr)));    \
  288.         break;                    \
  289.     default:                    \
  290.         __pu_err = __put_user_bad();        \
  291.         break;                    \
  292.     }                        \
  293.     __pu_err;                    \
  294. })
  295. #define __put_user(x, ptr) put_user(x, ptr)

  297. extern int __put_user_bad(void);

  299. #define get_user(x, ptr)                \
  300. ({                            \
  301.     int __gu_err = 0;                \
  302.     typeof(*(ptr)) __gu_val = 0;            \
  303.     switch (sizeof(*(ptr))) {            \
  304.     case 1:                        \
  305.     case 2:                        \
  306.     case 4:                        \
  307.     case 8:                        \
  308.         memcpy(&__gu_val, ptr, sizeof(*(ptr)));    \
  309.         break;                    \
  310.     default:                    \
  311.         __gu_val = 0;                \
  312.         __gu_err = __get_user_bad();        \
  313.         break;                    \
  314.     }                        \
  315.     (x) = __gu_val;                    \
  316.     __gu_err;                    \
  317. })
  318. #define __get_user(x, ptr) get_user(x, ptr)

  320. extern int __get_user_bad(void);

  322. #endif /* CONFIG_MMU */

  324. #endif /* _ASM_NIOS2_UACCESS_H */

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给主人留下些什么吧！~~

图片MM2012-03-30 01:08:55

是啊……自己添加驱动程序时。编译时会出错

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图片MM2012-03-30 01:07:25

好长的代码呀……

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