請教：段錯誤后GDB調(diào)試沒有任何信息

highnjupt

代碼跑個一天左右，總出現(xiàn)段錯誤；用GDB跟了下，但是出錯后GDB沒有任何提示信息，打印堆棧信息也是空的。

程序中有些庫是第三方提供的，沒有加-g，自己能控制的部分都加了-g；

同時程序出錯后也沒有core信息，ulimit -s 1024 這些也都加過；

交流下什么情況下，段錯誤后GDB調(diào)試沒有任何信息?

highnjupt

CU最近很冷啊

T-Bagwell

ulimit -c unlimited

會生成cordump

highnjupt

回復(fù) 3# T-Bagwell

謝謝版主回復(fù)，這樣使用也還是產(chǎn)生不了
   

T-Bagwell

求文件系統(tǒng)格式
至少文件系統(tǒng)要保證能夠?qū)懳募?br />
舉例

1. 
   
2. [root@centos1 c_leard]#
   
3. [root@centos1 c_leard]# ls
   
4. a  test  test2.c  test.c
   
5. [root@centos1 c_leard]# cat test2.c
   
6. #include <stdio.h>
   
7. #include <string.h>
   
8. 
   
9. void fuck2()
   
10. {
    
11.         char *test = "abcdefg";
    
12.         strcpy(test, "fuck");
    
13. }
    
14. void fuck1()
    
15. {
    
16.         fuck2();
    
17. }
    
18. void fuck ()
    
19. {
    
20.         fuck1();
    
21. }
    
22. int main()
    
23. {
    
24.         fuck();
    
25.         return ;
    
26. }
    
27. [root@centos1 c_leard]# gcc test2.c -o test2
    
28. [root@centos1 c_leard]# ulimit -c unlimited
    
29. [root@centos1 c_leard]# ./test2
    
30. Segmentation fault (core dumped)
    
31. [root@centos1 c_leard]# ls
    
32. a  core.2669  test  test2  test2.c  test.c
    
33. [root@centos1 c_leard]# gdb -c core.2669 ./test2
    
34. GNU gdb (GDB) Red Hat Enterprise Linux (7.1-29.el6)
    
35. Copyright (C) 2010 Free Software Foundation, Inc.
    
36. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
    
37. This is free software: you are free to change and redistribute it.
    
38. There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
    
39. and "show warranty" for details.
    
40. This GDB was configured as "x86_64-redhat-linux-gnu".
    
41. For bug reporting instructions, please see:
    
42. <http://www.gnu.org/software/gdb/bugs/>...
    
43. Reading symbols from /root/c_leard/test2...(no debugging symbols found)...done.
    
44. [New Thread 2669]
    
45. Missing separate debuginfo for
    
46. Try: yum --disablerepo='*' --enablerepo='*-debuginfo' install /usr/lib/debug/.build-id/e3/288ac29ed63015d8781dcf763cafadd212d6c9
    
47. Reading symbols from /lib64/libc.so.6...(no debugging symbols found)...done.
    
48. Loaded symbols for /lib64/libc.so.6
    
49. Reading symbols from /lib64/ld-linux-x86-64.so.2...(no debugging symbols found)...done.
    
50. Loaded symbols for /lib64/ld-linux-x86-64.so.2
    
51. Core was generated by `./test2'.
    
52. Program terminated with signal 11, Segmentation fault.
    
53. #0  0x00007fe797b4dd21 in memcpy () from /lib64/libc.so.6
    
54. Missing separate debuginfos, use: debuginfo-install glibc-2.12-1.7.el6.x86_64
    
55. (gdb) bt
    
56. #0  0x00007fe797b4dd21 in memcpy () from /lib64/libc.so.6
    
57. #1  0x00000000004004ed in fuck2 ()
    
58. #2  0x00000000004004fd in fuck1 ()
    
59. #3  0x000000000040050d in fuck ()
    
60. #4  0x000000000040051d in main ()
    
61. (gdb)
    
62. 
    

復(fù)制代碼

highnjupt

回復(fù) 5# T-Bagwell


   ext3的文件系統(tǒng)

寫個段錯誤的小例程，core dump會產(chǎn)生
在整個代碼里認為的加上段錯誤，gdb也能提示到相應(yīng)的信息
但是整個代碼跑著跑著出來段錯誤后，就沒有任何提示信息，只有
Segmentation fault

T-Bagwell

highnjupt 發(fā)表于 2012-05-02 08:26
回復(fù) 5# T-Bagwell

請參考我的調(diào)試過程

highnjupt

回復(fù) 7# T-Bagwell

core文件產(chǎn)生了，之前運行的時候文件系統(tǒng)設(shè)置成了只讀的，所以一直沒有產(chǎn)生core文件。

core文件產(chǎn)生提示的是在malloc里面出了問題，GDB調(diào)試信息：

1. Program terminated with signal 11, Segmentation fault.
   
2. [New process 894]
   
3. [New process 922]
   
4. [New process 955]
   
5. [New process 892]
   
6. [New process 891]
   
7. [New process 895]
   
8. [New process 896]
   
9. [New process 916]
   
10. [New process 917]
    
11. [New process 918]
    
12. [New process 919]
    
13. [New process 923]
    
14. [New process 924]
    
15. [New process 926]
    
16. [New process 927]
    
17. [New process 949]
    
18. [New process 928]
    
19. [New process 971]
    
20. [New process 930]
    
21. [New process 978]
    
22. [New process 931]
    
23. [New process 983]
    
24. [New process 932]
    
25. [New process 984]
    
26. [New process 933]
    
27. [New process 1000]
    
28. [New process 934]
    
29. [New process 1007]
    
30. [New process 936]
    
31. [New process 1013]
    
32. [New process 893]
    
33. [New process 937]
    
34. [New process 897]
    
35. [New process 938]
    
36. [New process 941]
    
37. [New process 935]
    
38. [New process 939]
    
39. [New process 943]
    
40. [New process 921]
    
41. [New process 940]
    
42. [New process 929]
    
43. [New process 942]
    
44. [New process 914]
    
45. [New process 944]
    
46. [New process 982]
    
47. [New process 945]
    
48. [New process 925]
    
49. [New process 946]
    
50. [New process 947]
    
51. [New process 948]
    
52. [New process 1012]
    
53. [New process 950]
    
54. [New process 1004]
    
55. [New process 951]
    
56. [New process 952]
    
57. [New process 1003]
    
58. [New process 953]
    
59. [New process 954]
    
60. [New process 1002]
    
61. [New process 957]
    
62. [New process 1001]
    
63. [New process 958]
    
64. [New process 999]
    
65. [New process 959]
    
66. [New process 960]
    
67. [New process 998]
    
68. [New process 961]
    
69. [New process 997]
    
70. [New process 962]
    
71. [New process 996]
    
72. [New process 963]
    
73. [New process 995]
    
74. [New process 964]
    
75. [New process 965]
    
76. [New process 994]
    
77. [New process 966]
    
78. [New process 993]
    
79. [New process 967]
    
80. [New process 988]
    
81. [New process 968]
    
82. [New process 987]
    
83. [New process 986]
    
84. [New process 969]
    
85. [New process 985]
    
86. [New process 970]
    
87. [New process 981]
    
88. [New process 920]
    
89. [New process 980]
    
90. [New process 979]
    
91. [New process 977]
    
92. [New process 972]
    
93. [New process 976]
    
94. [New process 974]
    
95. [New process 975]
    
96. #0  0x0043fe30 in malloc ()
    
97. (gdb) bt
    
98. #0  0x0043fe30 in malloc ()
    
99. Cannot access memory at address 0xbe5ff09c

復(fù)制代碼

暫時還沒確定是項目中的那個模塊出了問題
請教下版主：提示malloc的這種錯誤是指針越界了還是有野指針存在呢？

T-Bagwell

通過你的信息看出來，你這是一個很龐大的工程。。。

malloc段錯誤的話，一般是你在malloc之前用內(nèi)存用的不對
這個問題需要你仔細看代碼了

highnjupt

謝謝版主回復(fù):wink:

確實是個比較大的工程，主要修改了和業(yè)務(wù)相關(guān)的一個庫，其他的代碼全是原有產(chǎn)品上移植過來，平臺也有更換過