glibc库版本查看和动态库增加可执行属性
文章目录
glibc库版本查看和动态库增加可执行属性
1.查看当前glibc版本
2. 动态库增加版本信息
3. 源码下载
1.查看当前glibc版本
查看当前系统的glibc版本:
#/lib/libc.so.6
#/lib/x86-64-linux/libc.so.6
➜ ~ /lib64/libc.so.6
GNU C Library (GNU libc) stable release version 2.17, by Roland McGrath et al.
Copyright (C) 2012 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Compiled by GNU CC version 4.8.5 20150623 (Red Hat 4.8.5-44).
Compiled on a Linux 3.10.0 system on 2021-02-08.
Available extensions:
The C stubs add-on version 2.1.2.
crypt add-on version 2.1 by Michael Glad and others
GNU Libidn by Simon Josefsson
Native POSIX Threads Library by Ulrich Drepper et al
BIND-8.2.3-T5B
RT using linux kernel aio
libc ABIs: UNIQUE IFUNC
For bug reporting instructions, please see:
# 因为ldd命令也是glibc提供的，所以也能查看
➜ ~ ldd --version
ldd (GNU libc) 2.17
Copyright (C) 2012 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Written by Roland McGrath and Ulrich Drepper.
为什么这个库可以直接run呢？ 原来在libc的代码中有一点小手脚:
Makerules:708:
# Give libc.so an entry point and make it directly runnable itself.
LDFLAGS-c.so += -e __libc_main
查看__libc_main函数的实现
/* Copyright (C) 1992-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
#include "version.h"