![我的组(根据 /bin/id)对 Char 设备具有 rw 访问权限,但访问被拒绝](https://linux22.com/image/1390977/%E6%88%91%E7%9A%84%E7%BB%84%EF%BC%88%E6%A0%B9%E6%8D%AE%20%2Fbin%2Fid%EF%BC%89%E5%AF%B9%20Char%20%E8%AE%BE%E5%A4%87%E5%85%B7%E6%9C%89%20rw%20%E8%AE%BF%E9%97%AE%E6%9D%83%E9%99%90%EF%BC%8C%E4%BD%86%E8%AE%BF%E9%97%AE%E8%A2%AB%E6%8B%92%E7%BB%9D.png)
我在群里graphics
shell@lt03wifi:/ $ id
uid=2000(shell) gid=2000(shell) groups=1003(graphics),1004(input),1007(log),1009(mount),1011(adb),1015(sdcard_rw),1028(sdcard_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats) context=u:r:shell:s0
该字符设备/dev/graphics/fb0
被标记为我的组可访问 (rw):
shell@lt03wifi:/ $ ls -l /dev/graphics/fb0
crw-rw---- root graphics 29, 0 2013-12-24 23:30 fb0*
shell@lt03wifi:/ $ mount | grep "/dev "
tmpfs /dev tmpfs rw,seclabel,nosuid,relatime,size=1421696k,nr_inodes=114626,mode=755 0 0
但我被拒绝访问(为什么?):
shell@lt03wifi:/ $ cd data/data/com.spartacusrex.spartacuside/files/system/bin
shell@lt03wifi:/data/data/com.spartacusrex.spartacuside/files/system/bin $ ./grep -l . /dev/graphics/fb0
grep: /dev/graphics/fb0: Permission denied
测试可执行grep
文件有效,见:
shell@lt03wifi:/data/data/com.spartacusrex.spartacuside/files/system/bin $ ./grep -l . grep
./grep
为什么我被拒绝访问该字符设备?