Linux chcon:修改文件安全上下文(security context)

[root@hadoop1 hadoop-2.7.2]# chcon --help
Usage: chcon [OPTION]... CONTEXT FILE...
  or:  chcon [OPTION]... [-u USER] [-r ROLE] [-l RANGE] [-t TYPE] FILE...
  or:  chcon [OPTION]... --reference=RFILE FILE...
Change the security context of each FILE to CONTEXT.

  -c, --changes          like verbose but report only when a change is made
  -h, --no-dereference   affect symbolic links instead of any referenced file
                         (available only on systems with lchown system call)
  -f, --silent, --quiet  suppress most error messages
      --reference=RFILE  use RFILE's context instead of using a CONTEXT value
  -u, --user=USER        set user USER in the target security context
  -r, --role=ROLE        set role ROLE in the target security context
  -t, --type=TYPE        set type TYPE in the target security context
  -l, --range=RANGE      set range RANGE in the target security context
  -R, --recursive        change files and directories recursively
  -v, --verbose          output a diagnostic for every file processed
      --help             display this help and exit
      --version          output version information and exit

字面上理解，就是修改文件安全上下文，感觉跟selinux有关。

比如，在安装jdk7的时候，可能会遇到这个错(在安装jdk6时没遇到这个错，装jdk7的时候遇到了,hadoop2.7是用jdk7编译的)

[root@hadoop1 jdk1.7.0_01]# java
Error: dl failure on line 875
Error: failed /home/devsoftware/jdk1.7.0_01/jre/lib/i386/client/libjvm.so, because /home/devsoftware/jdk1.7.0_01/jre/lib/i386/client/libjvm.so: cannot restore segment prot after reloc: Permission denied

这个时候，可以用chcon(应该是change context的编写吧)

chcon -t texrel_shlib_t /home/devsoftware/jdk1.7.0_01/jre/lib/i386/client/libjvm.so

如果问题还得不到解决，检查一下是否关闭selinux，即在/etc/selinux/config里把SELINUX改为disabled