中国建材建设网站,一对一直播网站开发,做外贸相关的网站,汕头高端模板建站这篇记录工作中发现的#xff0c;库文件被修改导致 yum 无法正常使用的问题排查过程 问题描述
1#xff09;执行yum 报错说python2.7.5 结构异常#xff0c;发现/usr/bin/yum 的解释器被修改过#xff0c;恢复成/usr/bin/python即可
2#xff09;恢复后#xff0c;发现… 这篇记录工作中发现的库文件被修改导致 yum 无法正常使用的问题排查过程 问题描述
1执行yum 报错说python2.7.5 结构异常发现/usr/bin/yum 的解释器被修改过恢复成/usr/bin/python即可
2恢复后发现执行yum依旧报错
# yum
There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:/lib64/libxml2.so.2: symbol gzopen64, version ZLIB_1.2.3.3 not defined in file libz.so.1 with link time referencePlease install a package which provides this module, or
verify that the module is installed correctly.Its possible that the above module doesnt match the
current version of Python, which is:
2.7.5 (default, Oct 30 2018, 23:45:53)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-36)]If you cannot solve this problem yourself, please go to
the yum faq at:http://yum.baseurl.org/wiki/Faq
处理过程
1、关于yum 报错python2.7.5 结构异常因为yum 和 dnf 其实都是一个用Python写的脚本所以如果有异常可以先看看/usr/bin/yum 或 /usr/bin/dnf 看看文件是否被修改过这里通过文件修改时间可以判断这个文件被动过
2、恢复/usr/bin/yum 另外看看解释器是哪个是否正常
3、恢复/usr/bin/yum 后发现第一个报错没了另外有个新的报错问题并不简单
4、尝试通过/usr/bin/yum 指定的 Python 解释器去复现一下报错
# more /usr/bin/yum
大概能看到实际就是导入了 yum 等几个模块尝试用指定的解释器 import 看看
# /usr/bin/python
Python 2.7.5 (default, Oct 30 2018, 23:45:53)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-36)] on linux2
Type help, copyright, credits or license for more information.import yum
Traceback (most recent call last):File stdin, line 1, in moduleFile /usr/lib/python2.7/site-packages/yum/__init__.py, line 62, in moduleimport rpmsackFile /usr/lib/python2.7/site-packages/yum/rpmsack.py, line 38, in moduleimport yum.depsolveFile /usr/lib/python2.7/site-packages/yum/depsolve.py, line 30, in modulefrom transactioninfo import TransactionMemberFile /usr/lib/python2.7/site-packages/yum/transactioninfo.py, line 32, in modulefrom sqlitesack import YumAvailablePackageSqliteFile /usr/lib/python2.7/site-packages/yum/sqlitesack.py, line 26, in moduleimport yumRepoFile /usr/lib/python2.7/site-packages/yum/yumRepo.py, line 35, in moduleimport sqlitecachecFile /usr/lib64/python2.7/site-packages/sqlitecachec.py, line 19, in moduleimport _sqlitecache
ImportError: /lib64/libxml2.so.2: symbol gzopen64, version ZLIB_1.2.3.3 not defined in file libz.so.1 with link time reference5、这里大致就清楚了多半是模块或者库文件也被动过尝试将相同版本正常机器的 yum 模块复制过来在正常机器import yum 打印 yum 看看在什么位置 import yumyum
module yum from /usr/lib/python2.7/site-packages/yum/__init__.pyc
6、将模块文件导入了以后仍然没有恢复这时候排除了模块文件被修改后考虑软件版本或者相关文件被修改对比未发现异常
# rpm -qa|grep -i ZLIB
zlib-1.2.7-18.el7.x86_64
# rpm -ql zlib-1.2.7-18.el7.x86_64
/usr/lib64/libz.so.1
/usr/lib64/libz.so.1.2.7
/usr/share/doc/zlib-1.2.7
/usr/share/doc/zlib-1.2.7/ChangeLog
/usr/share/doc/zlib-1.2.7/FAQ
/usr/share/doc/zlib-1.2.7/README
7、考虑库文件被修改发现上述库报错/lib/libz.so.1 这个库异常
查看共享库依赖
# ldd /lib64/libxml2.so.2
/lib64/libxml2.so.2: /lib/libz.so.1: no version information available (required by /lib64/libxml2.so.2)
/lib64/libxml2.so.2: /lib/libz.so.1: no version information available (required by /lib64/libxml2.so.2)
linux-vdso.so.1 (0x00007ffe5ebfa000)
libdl.so.2 /lib64/libdl.so.2 (0x00007fd741cd7000)
libz.so.1 /lib/libz.so.1 (0x00007fd741ac1000)
liblzma.so.5 /lib64/liblzma.so.5 (0x00007fd74189b000)
libm.so.6 /lib64/libm.so.6 (0x00007fd741599000)
libc.so.6 /lib64/libc.so.6 (0x00007fd7411cc000)
/lib64/ld-linux-x86-64.so.2 (0x00007fd742245000)
libpthread.so.0 /lib64/libpthread.so.0 (0x00007fd740fb0000)
与正常库对比
# ldd /lib64/libxml2.so.2
linux-vdso.so.1 (0x00007ffe7c7d4000)
libdl.so.2 /lib64/libdl.so.2 (0x00002aac91eea000)
libz.so.1 /lib64/libz.so.1 (0x00002aac920ee000)
liblzma.so.5 /lib64/liblzma.so.5 (0x00002aac92304000)
libm.so.6 /lib64/libm.so.6 (0x00002aac9252a000)
libc.so.6 /lib64/libc.so.6 (0x00002aac9282c000)
/lib64/ld-linux-x86-64.so.2 (0x00002aac9195c000)
libpthread.so.0 /lib64/libpthread.so.0 (0x00002aac92bfa000)
# ldd /lib/libz.so.1
ldd: /lib/libz.so.1: No such file or directory
# ll /lib/libz.so.1
lrwxrwxrwx. 1 root root 7 May 28 2020 /lib/libz.so.1 - libz.so
8、依据对比可以发现库文件被指向了32位的库文件目录以及一个错误的库文件参考正常的服务器配置即可问题解决
# rm /lib/libz.so.1
# ln -s /lib64/libz.so.1 /lib/libz.so.1
9、回溯这个就不继续写了大致就是看看last / history操作记录
总结
1、这次主要是了解了ldd 对动态共享库的信息分析
2、这种动态库修改的不太好发现需要依据报错逐步分析出现异常的动态库
3、nm -C -D 库文件路径 可以查看库文件信息不过没研究内容啥意思
