求救~~ C函数中形参的异常变化

denry39

Arch:  ARM-LINUX

在我的源程序中有:

1. static int *buf_pointer[NUM_BUF]；
   
2. if(MAP_FAILED == (buf_pointer[i] = mmap(.......))
   
3. ........
   
4. // 断点设置点
   
5. if(v4lconvert_convert(lib, &src_fmt, &dst_fmt, (void*)buf_pointer[cam_buf.index],
   
6.                 cam_buf.length, current_pic.buffer, YUV420_size) <= 0)
   

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in libv4lconvert.c(库函数)

1. 
   
2. 947 int v4lconvert_convert(struct v4lconvert_data *data,
   
3. 948   const struct v4l2_format *src_fmt,  /* in */
   
4. 949   const struct v4l2_format *dest_fmt, /* in */
   
5. 950   unsigned char *src, int src_size, unsigned char *dest, int dest_size)
   
6. 951 {
   
7. 952   int res, dest_needed, temp_needed, processing, convert = 0;
   
8. 953   int rotate90, vflip, hflip, crop;
   
9. 954   unsigned char *convert1_dest = dest;
   
10. 955   int convert1_dest_size = dest_size;
    
11. 956   unsigned char *convert2_src = src, *convert2_dest = dest;
    
12. 957   int convert2_dest_size = dest_size;
    
13. 958   unsigned char *rotate90_src = src, *rotate90_dest = dest;
    
14. 959   unsigned char *flip_src = src, *flip_dest = dest;
    
15. 960   unsigned char *crop_src = src;
    
16. 961   struct v4l2_format my_src_fmt = *src_fmt;   //问题代码
    
17. 962   struct v4l2_format my_dest_fmt = *dest_fmt;
    

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GDB调试:

1. (gdb) b v4lconvert_convert   //设置断点
   
2. (gdb) r
   
3. Breakpoint 1, v4lconvert_convert (data=0x19008, src_fmt=0x189b8,
   
4.     dest_fmt=0x188ec, src=0x4042b000 <Address 0x4042b000 out of bounds>,
   
5.     src_size=0, dest=0x40895008 "", dest_size=460800) at libv4lconvert.c:1004
   
6. 1004    libv4lconvert.c: No such file or directory.
   
7.         in libv4lconvert.c
   
8. (gdb) n
   
9. 951     in libv4lconvert.c
   
10. (gdb) n
    
11. 961     in libv4lconvert.c
    
12. (gdb) bt
    
13. #0  v4lconvert_convert (data=0x19008, src_fmt=0x189b8, dest_fmt=0x188ec,
    
14.     src=0x4042b000 <Address 0x4042b000 out of bounds>, src_size=0,
    
15.     dest=0x40895008 "", dest_size=460800) at libv4lconvert.c:961
    
16. #1  0x000096e8 in camera_get_frame (pic=0xbefffc58) at camera.c:181
    
17. #2  0x00009fd4 in main () at main.c:56
    
18. (gdb) p src
    
19. $7 = (unsigned char *) 0x4042b000 <Address 0x4042b000 out of bounds>
    
20. (gdb) n
    
21. 962     in libv4lconvert.c
    
22. (gdb) p src
    
23. $8 = (unsigned char *) 0x189b8 "\001"   //src 值改变
    
24. (gdb) bt
    
25. #0  v4lconvert_convert (data=0x19008, src_fmt=0x0, dest_fmt=0x188ec,
    
26.     src=0x189b8 "\001", src_size=0, dest=0x40895008 "", dest_size=460800)
    
27.     at libv4lconvert.c:962      //src_fmt,  src均改变
    
28. #1  0x000096e8 in camera_get_frame (pic=0xbefffc58) at camera.c:181
    
29. #2  0x00009fd4 in main () at main.c:56
    
30. (gdb)
    

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问题：
1. mmap并没有出错，返回的地址在函数调用中怎么会"out of bounds”
2. 在执行了v4lconvert_convert的第961行后，函数的src_fmt,src形参值怎么会发生变化，不解呀。请高人指教。。。。