coredump的生成以及gdb查看
coredump是记录了特点时间某一进程的内存状态，主要是内存的寄存器、堆栈、其他内存信息，本文件简述下coredump生成以及使用gdb查看的方式
一、默认不生成coredump
[root@linux mcheck]# ./main
p=0x14a39010
after free p one time
*** glibc detected *** ./main: double free or corruption (fasttop): 0x0000000014a39010 ***
======= Backtrace: =========
/lib64/libc.so.6[0x380fc7245f]
/lib64/libc.so.6(cfree+0x4b)[0x380fc728bb]
./main[0x4005ad]
/lib64/libc.so.6(__libc_start_main+0xf4)[0x380fc1d994]
./main[0x4004b9]
======= Memory map: ========
00400000-00401000 r-xp 00000000 08:02 210141200 /home/lijiancheng/test/mcheck/main
00600000-00601000 rw-p 00000000 08:02 210141200 /home/lijiancheng/test/mcheck/main
14a39000-14a5a000 rw-p 14a39000 00:00 0 [heap]
380f400000-380f41c000 r-xp 00000000 08:02 143884625 /lib64/ld-2.5.so
380f61c000-380f61d000 r--p 0001c000 08:02 143884625 /lib64/ld-2.5.so
380f61d000-380f61e000 rw-p 0001d000 08:02 143884625 /lib64/ld-2.5.so
380fc00000-380fd4e000 r-xp 00000000 08:02 143884626 /lib64/libc-2.5.so
380fd4e000-380ff4e000 ---p 0014e000 08:02 143884626 /lib64/libc-2.5.so
380ff4e000-380ff52000 r--p 0014e000 08:02 143884626 /lib64/libc-2.5.so
380ff52000-380ff53000 rw-p 00152000 08:02 143884626 /lib64/libc-2.5.so
380ff53000-380ff58000 rw-p 380ff53000 00:00 0
3811c00000-3811c0d000 r-xp 00000000 08:02 143884638 /lib64/libgcc_s-4.1.2-20080825.so.1
3811c0d000-3811e0d000 ---p 0000d000 08:02 143884638 /lib64/libgcc_s-4.1.2-20080825.so.1
3811e0d000-3811e0e000 rw-p 0000d000 08:02 143884638 /lib64/libgcc_s-4.1.2-20080825.so.1
2b702636e000-2b7026371000 rw-p 2b702636e000 00:00 0
2b702639c000-2b702639d000 rw-p 2b702639c000 00:00 0
7fff15ef4000-7fff15f09000 rw-p 7ffffffe9000 00:00 0 [stack]
7fff15ffd000-7fff16000000 r-xp 7fff15ffd000 00:00 0 [vdso]
ffffffffff600000-ffffffffffe00000 ---p 00000000 00:00 0 [vsyscall]
Aborted 未生成coredump
[root@linux mcheck]# ls -l
总计 28
-rwxr-xr-x 1 root root 7168 08-09 10:25 main
-rw-r--r-- 1 root root 1009 08-09 17:40 main.c
-rw-r--r-- 1 root root 1856 08-09 17:40 main.o
二、打开coredump生成开关，（一般在开机脚本或者配置中）
[root@linux mcheck]# ./main
p=0x4ce6010
after free p one time
*** glibc detected *** ./main: double free or corruption (fasttop): 0x0000000004ce6010 ***
======= Backtrace: =========
/lib64/libc.so.6[0x380fc7245f]
/lib64/libc.so.6(cfree+0x4b)[0x380fc728bb]
./main[0x4005ad]
/lib64/libc.so.6(__libc_start_main+0xf4)[0x380fc1d994]
./main[0x4004b9]
======= Memory map: ========
00400000-00401000 r-xp 00000000 08:02 210141200 /home/lijiancheng/test/mcheck/main
00600000-00601000 rw-p 00000000 08:02 210141200 /home/lijiancheng/test/mcheck/main
04ce6000-04d07000 rw-p 04ce6000 00:00 0 [heap]
380f400000-380f41c000 r-xp 00000000 08:02 143884625 /lib64/ld-2.5.so
380f61c000-380f61d000 r--p 0001c000 08:02 143884625 /lib64/ld-2.5.so
380f61d000-380f61e000 rw-p 0001d000 08:02 143884625 /lib64/ld-2.5.so
380fc00000-380fd4e000 r-xp 00000000 08:02 143884626 /lib64/libc-2.5.so
380fd4e000-380ff4e000 ---p 0014e000 08:02 143884626 /lib64/libc-2.5.so
380ff4e000-380ff52000 r--p 0014e000 08:02 143884626 /lib64/libc-2.5.so
380ff52000-380ff53000 rw-p 00152000 08:02 143884626 /lib64/libc-2.5.so
380ff53000-380ff58000 rw-p 380ff53000 00:00 0
3811c00000-3811c0d000 r-xp 00000000 08:02 143884638 /lib64/libgcc_s-4.1.2-20080825.so.1
3811c0d000-3811e0d000 ---p 0000d000 08:02 143884638 /lib64/libgcc_s-4.1.2-20080825.so.1
3811e0d000-3811e0e000 rw-p 0000d000 08:02 143884638 /lib64/libgcc_s-4.1.2-20080825.so.1
2b244007f000-2b2440082000 rw-p 2b244007f000 00:00 0
2b24400ad000-2b24400ae000 rw-p 2b24400ad000 00:00 0
7ffffd090000-7ffffd0a5000 rw-p 7ffffffe9000 00:00 0 [stack]
7ffffd1fd000-7ffffd200000 r-xp 7ffffd1fd000 00:00 0 [vdso]
ffffffffff600000-ffffffffffe00000 ---p 00000000 00:00 0 [vsyscall]
Aborted (core dumped) 此时显示coredump已经生成了
[root@linux mcheck]# ls -l
total 140
-rw------- 1 root root 315392 Sep 3 09:43 core.25298 生成的coredump文件
-rwxr-xr-x 1 root root 7168 Aug 9 10:25 main
-rw-r--r-- 1 root root 1009 Aug 9 17:40 main.c
-rw-r--r-- 1 root root 1856 Aug 9 17:40 main.o
四、可以用gdb对coredump进行查看
[root@linux mcheck]# gdb ./main ./core.25298
GNU gdb (GDB) Red Hat Enterprise Linux (7.0.1-37.el5)
Copyright (C) 2009 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 "x86_64-redhat-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /home/lijiancheng/test/mcheck/main...(no debugging symbols found)...done.
[New Thread 25298]
Reading symbols from /lib64/libc.so.6...(no debugging symbols found)...done.
Loaded symbols for /lib64/libc.so.6
Reading symbols from /lib64/ld-linux-x86-64.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib64/ld-linux-x86-64.so.2
Reading symbols from /lib64/libgcc_s.so.1...(no debugging symbols found)...done.
Loaded symbols for /lib64/libgcc_s.so.1
warning: no loadable sections found in added symbol-file system-supplied DSO at 0x7ffffd1fd000
Core was generated by `./main'.
Program terminated with signal 6, Aborted.
#0 0x000000380fc30265 in raise () from /lib64/libc.so.6
(gdb) bt
#0 0x000000380fc30265 in raise () from /lib64/libc.so.6
#1 0x000000380fc31d10 in abort () from /lib64/libc.so.6
#2 0x000000380fc6a99b in __libc_message () from /lib64/libc.so.6
#3 0x000000380fc7245f in _int_free () from /lib64/libc.so.6
#4 0x000000380fc728bb in free () from /lib64/libc.so.6
#5 0x00000000004005ad in main ()
(gdb) info registers
rax 0x0 0
rbx 0x7ffffd0a1ae0 140737438685920
rcx 0xffffffffffffffff -1
rdx 0x6 6
rsi 0x62d2 25298
rdi 0x62d2 25298
rbp 0x2b24400ad6e0 0x2b24400ad6e0
rsp 0x7ffffd0a1a38 0x7ffffd0a1a38
r8 0x80 128
r9 0x101010101010101 72340172838076673
r10 0x8 8
r11 0x246 582
r12 0x4 4
r13 0x7ffffd0a1d60 140737438686560
r14 0x7ffffd0a1c00 140737438686208
r15 0x380fd22b28 240783600424
rip 0x380fc30265 0x380fc30265 <raise+53>
eflags 0x246 [ PF ZF IF ]
cs 0x33 51
ss 0x2b 43
ds 0x0 0
es 0x0 0
fs 0x0 0
gs 0x0 0
fctrl 0x37f 895
fstat 0x0 0
ftag 0xffff 65535
fiseg 0x0 0
fioff 0x0 0
foseg 0x0 0
fooff 0x0 0
fop 0x0 0
mxcsr 0x1f80 [ IM DM ZM OM UM PM ]
(gdb) quit
一、默认不生成coredump
[root@linux mcheck]# ./main
p=0x14a39010
after free p one time
*** glibc detected *** ./main: double free or corruption (fasttop): 0x0000000014a39010 ***
======= Backtrace: =========
/lib64/libc.so.6[0x380fc7245f]
/lib64/libc.so.6(cfree+0x4b)[0x380fc728bb]
./main[0x4005ad]
/lib64/libc.so.6(__libc_start_main+0xf4)[0x380fc1d994]
./main[0x4004b9]
======= Memory map: ========
00400000-00401000 r-xp 00000000 08:02 210141200 /home/lijiancheng/test/mcheck/main
00600000-00601000 rw-p 00000000 08:02 210141200 /home/lijiancheng/test/mcheck/main
14a39000-14a5a000 rw-p 14a39000 00:00 0 [heap]
380f400000-380f41c000 r-xp 00000000 08:02 143884625 /lib64/ld-2.5.so
380f61c000-380f61d000 r--p 0001c000 08:02 143884625 /lib64/ld-2.5.so
380f61d000-380f61e000 rw-p 0001d000 08:02 143884625 /lib64/ld-2.5.so
380fc00000-380fd4e000 r-xp 00000000 08:02 143884626 /lib64/libc-2.5.so
380fd4e000-380ff4e000 ---p 0014e000 08:02 143884626 /lib64/libc-2.5.so
380ff4e000-380ff52000 r--p 0014e000 08:02 143884626 /lib64/libc-2.5.so
380ff52000-380ff53000 rw-p 00152000 08:02 143884626 /lib64/libc-2.5.so
380ff53000-380ff58000 rw-p 380ff53000 00:00 0
3811c00000-3811c0d000 r-xp 00000000 08:02 143884638 /lib64/libgcc_s-4.1.2-20080825.so.1
3811c0d000-3811e0d000 ---p 0000d000 08:02 143884638 /lib64/libgcc_s-4.1.2-20080825.so.1
3811e0d000-3811e0e000 rw-p 0000d000 08:02 143884638 /lib64/libgcc_s-4.1.2-20080825.so.1
2b702636e000-2b7026371000 rw-p 2b702636e000 00:00 0
2b702639c000-2b702639d000 rw-p 2b702639c000 00:00 0
7fff15ef4000-7fff15f09000 rw-p 7ffffffe9000 00:00 0 [stack]
7fff15ffd000-7fff16000000 r-xp 7fff15ffd000 00:00 0 [vdso]
ffffffffff600000-ffffffffffe00000 ---p 00000000 00:00 0 [vsyscall]
Aborted 未生成coredump
[root@linux mcheck]# ls -l
总计 28
-rwxr-xr-x 1 root root 7168 08-09 10:25 main
-rw-r--r-- 1 root root 1009 08-09 17:40 main.c
-rw-r--r-- 1 root root 1856 08-09 17:40 main.o
二、打开coredump生成开关，（一般在开机脚本或者配置中）
[root@linux mcheck]# ulimit -c unlimited
[root@linux mcheck]# ./main
p=0x4ce6010
after free p one time
*** glibc detected *** ./main: double free or corruption (fasttop): 0x0000000004ce6010 ***
======= Backtrace: =========
/lib64/libc.so.6[0x380fc7245f]
/lib64/libc.so.6(cfree+0x4b)[0x380fc728bb]
./main[0x4005ad]
/lib64/libc.so.6(__libc_start_main+0xf4)[0x380fc1d994]
./main[0x4004b9]
======= Memory map: ========
00400000-00401000 r-xp 00000000 08:02 210141200 /home/lijiancheng/test/mcheck/main
00600000-00601000 rw-p 00000000 08:02 210141200 /home/lijiancheng/test/mcheck/main
04ce6000-04d07000 rw-p 04ce6000 00:00 0 [heap]
380f400000-380f41c000 r-xp 00000000 08:02 143884625 /lib64/ld-2.5.so
380f61c000-380f61d000 r--p 0001c000 08:02 143884625 /lib64/ld-2.5.so
380f61d000-380f61e000 rw-p 0001d000 08:02 143884625 /lib64/ld-2.5.so
380fc00000-380fd4e000 r-xp 00000000 08:02 143884626 /lib64/libc-2.5.so
380fd4e000-380ff4e000 ---p 0014e000 08:02 143884626 /lib64/libc-2.5.so
380ff4e000-380ff52000 r--p 0014e000 08:02 143884626 /lib64/libc-2.5.so
380ff52000-380ff53000 rw-p 00152000 08:02 143884626 /lib64/libc-2.5.so
380ff53000-380ff58000 rw-p 380ff53000 00:00 0
3811c00000-3811c0d000 r-xp 00000000 08:02 143884638 /lib64/libgcc_s-4.1.2-20080825.so.1
3811c0d000-3811e0d000 ---p 0000d000 08:02 143884638 /lib64/libgcc_s-4.1.2-20080825.so.1
3811e0d000-3811e0e000 rw-p 0000d000 08:02 143884638 /lib64/libgcc_s-4.1.2-20080825.so.1
2b244007f000-2b2440082000 rw-p 2b244007f000 00:00 0
2b24400ad000-2b24400ae000 rw-p 2b24400ad000 00:00 0
7ffffd090000-7ffffd0a5000 rw-p 7ffffffe9000 00:00 0 [stack]
7ffffd1fd000-7ffffd200000 r-xp 7ffffd1fd000 00:00 0 [vdso]
ffffffffff600000-ffffffffffe00000 ---p 00000000 00:00 0 [vsyscall]
Aborted (core dumped) 此时显示coredump已经生成了
[root@linux mcheck]# ls -l
total 140
-rw------- 1 root root 315392 Sep 3 09:43 core.25298 生成的coredump文件
-rwxr-xr-x 1 root root 7168 Aug 9 10:25 main
-rw-r--r-- 1 root root 1009 Aug 9 17:40 main.c
-rw-r--r-- 1 root root 1856 Aug 9 17:40 main.o
四、可以用gdb对coredump进行查看
[root@linux mcheck]# gdb ./main ./core.25298
GNU gdb (GDB) Red Hat Enterprise Linux (7.0.1-37.el5)
Copyright (C) 2009 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 "x86_64-redhat-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /home/lijiancheng/test/mcheck/main...(no debugging symbols found)...done.
[New Thread 25298]
Reading symbols from /lib64/libc.so.6...(no debugging symbols found)...done.
Loaded symbols for /lib64/libc.so.6
Reading symbols from /lib64/ld-linux-x86-64.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib64/ld-linux-x86-64.so.2
Reading symbols from /lib64/libgcc_s.so.1...(no debugging symbols found)...done.
Loaded symbols for /lib64/libgcc_s.so.1
warning: no loadable sections found in added symbol-file system-supplied DSO at 0x7ffffd1fd000
Core was generated by `./main'.
Program terminated with signal 6, Aborted.
#0 0x000000380fc30265 in raise () from /lib64/libc.so.6
(gdb) bt
#0 0x000000380fc30265 in raise () from /lib64/libc.so.6
#1 0x000000380fc31d10 in abort () from /lib64/libc.so.6
#2 0x000000380fc6a99b in __libc_message () from /lib64/libc.so.6
#3 0x000000380fc7245f in _int_free () from /lib64/libc.so.6
#4 0x000000380fc728bb in free () from /lib64/libc.so.6
#5 0x00000000004005ad in main ()
(gdb) info registers
rax 0x0 0
rbx 0x7ffffd0a1ae0 140737438685920
rcx 0xffffffffffffffff -1
rdx 0x6 6
rsi 0x62d2 25298
rdi 0x62d2 25298
rbp 0x2b24400ad6e0 0x2b24400ad6e0
rsp 0x7ffffd0a1a38 0x7ffffd0a1a38
r8 0x80 128
r9 0x101010101010101 72340172838076673
r10 0x8 8
r11 0x246 582
r12 0x4 4
r13 0x7ffffd0a1d60 140737438686560
r14 0x7ffffd0a1c00 140737438686208
r15 0x380fd22b28 240783600424
rip 0x380fc30265 0x380fc30265 <raise+53>
eflags 0x246 [ PF ZF IF ]
cs 0x33 51
ss 0x2b 43
ds 0x0 0
es 0x0 0
fs 0x0 0
gs 0x0 0
fctrl 0x37f 895
fstat 0x0 0
ftag 0xffff 65535
fiseg 0x0 0
fioff 0x0 0
foseg 0x0 0
fooff 0x0 0
fop 0x0 0
mxcsr 0x1f80 [ IM DM ZM OM UM PM ]
(gdb) quit