core dump

详细内容见man文档：

man 5 core。http://man7.org/linux/man-pages/man5/core.5.html

man ulimit

把上面的man文档看一遍就差不多了。

我遇到的问题是，没能成功生成coredump文件。

解决办法：使用ulimit 改变core文件大小限制。

$ ulimit -S -acore file size          (blocks, -c) 0data seg size           (kbytes, -d) unlimitedscheduling priority             (-e) 0file size               (blocks, -f) unlimitedpending signals                 (-i) 24110max locked memory       (kbytes, -l) 64max memory size         (kbytes, -m) unlimitedopen files                      (-n) 1024pipe size            (512 bytes, -p) 8POSIX message queues     (bytes, -q) 819200real-time priority              (-r) 0stack size              (kbytes, -s) 8192cpu time               (seconds, -t) unlimitedmax user processes              (-u) 1024virtual memory          (kbytes, -v) unlimitedfile locks                      (-x) unlimited

上面显示core file size 为0个block。把它改大点就能生成coredump文件了。

$ ulimit -S -acore file size          (blocks, -c) unlimiteddata seg size           (kbytes, -d) unlimitedscheduling priority             (-e) 0file size               (blocks, -f) unlimitedpending signals                 (-i) 24110max locked memory       (kbytes, -l) 64max memory size         (kbytes, -m) unlimitedopen files                      (-n) 1024pipe size            (512 bytes, -p) 8POSIX message queues     (bytes, -q) 819200real-time priority              (-r) 0stack size              (kbytes, -s) 8192cpu time               (seconds, -t) unlimitedmax user processes              (-u) 1024virtual memory          (kbytes, -v) unlimitedfile locks                      (-x) unlimited

这样问题就解决了。

注意这样只对当前终端有效。

设置好core 文件大小之后，可以调试一个core dump文件练练手。可以使用gdb 进行调试。

例子：

代码

main.c

int main(){char *p = "helloworld";p[0] = 'h';return 0;}

gcc -Wall -g main.c -o main

./main

会产生coredump文件，core.8151

gdb main core.8151  注意用gdb调试要带上原来的可执行文件，后面加上coredump文件。

$ gdb main core.8151 GNU gdb (GDB) Fedora (7.4.50.20120120-50.fc17)Copyright (C) 2012 Free Software Foundation, Inc.License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>This is free software: you are free to change and redistribute it.There is NO WARRANTY, to the extent permitted by law.  Type "show copying"and "show warranty" for details.This GDB was configured as "i686-redhat-linux-gnu".For bug reporting instructions, please see:<http://www.gnu.org/software/gdb/bugs/>...Reading symbols from /home/huntinux/work/linker_loader/coredump/main...done.[New LWP 8151]Core was generated by `./main'.Program terminated with signal 11, Segmentation fault.#0  0x080483e0 in main () at main.c:44p[0] = 'h';Missing separate debuginfos, use: debuginfo-install glibc-2.15-57.fc17.i686(gdb) l1int main()2{3char *p = "helloworld";4p[0] = 'h';56return 0;7}(gdb) b 4Breakpoint 1 at 0x80483dd: file main.c, line 4.(gdb) rStarting program: /home/huntinux/work/linker_loader/coredump/main Breakpoint 1, main () at main.c:44p[0] = 'h';(gdb) sProgram received signal SIGSEGV, Segmentation fault.0x080483e0 in main () at main.c:44p[0] = 'h';

参考： http://prefetch.net/blog/index.php/2012/01/19/using-the-automated-bug-reporting-tool-abrt-to-generate-core-dumps-when-a-linux-process-fails/

             http://man7.org/linux/man-pages/man5/core.5.html