How to remount and rewrite permissions in Linux

1. Enable the terminal;

2 ADB shell connection terminal. If it is not a root user, you need to manually switch to the root user, ADB root;

3. Enter the mount command to display the mounted list:

Rootfs/rootfs Ro, relatime 0 0
Tmpfs/dev tmpfs RW, nosuid, relatime, mode = 755 0 0
Devpts/dev/PTS devpts RW, relatime, mode = 600 0 0
Proc/proc RW, relatime 0 0
Sysfs/sys sysfs RW, relatime 0 0
None/Acct cgroup RW, relatime, cpuacct 0 0
Tmpfs/mnt/ASEC tmpfs RW, relatime, mode = 755, gid = 1000 0 0
Tmpfs/mnt/OBB tmpfs RW, relatime, mode = 755, gid = 1000 0 0
None/dev/cpuctl cgroup RW, relatime, CPU 0 0
/Dev/block/mmcblk0p12/system ext4 Ro, relatime, barrier = 1, data = ordered 0 0
/Dev/block/mmcblk0p20/Data ext4 RW, nosuid, nodev, relatime, barrier = 1, data = ordered, noauto_da_alloc 0 0
/Dev/block/mmcblk0p14/persist ext4 RW, nosuid, nodev, relatime, barrier = 1, data = ordered 0 0
/Dev/block/mmcblk0p15/cache ext4 RW, nosuid, nodev, relatime, barrier = 1, data = ordered 0 0
/Dev/block/mmcblk0p13/system/flex ext4 Ro, nosuid, nodev, relatime, barrier = 1, data = ordered 0 0
/Dev/block/mmcblk0p16/tombstones ext4 RW, nosuid, nodev, relatime, barrier = 1, data = ordered 0 0
/Dev/block/mmcblk0p1/firmware vfat Ro, relatime, fmask = 0000, dmask = 0000, allow_utime = 0022, codePage = cp437, iocharset = iso8859-1, shortname = lower, errors = remount-ro 0 0
/Dev/fuse/emmc fuse RW, nosuid, nodev, relatime, user_id = 1023, group_id = 1023, default_permissions, allow_other 0 0
#
4. Find the Mount directory for which you want to modify the permission, for example,/system/dev/block/mmcblk0p12. Mount the directory as follows:

Mount-o rw, remount/system/dev/block/mmcblk0p12 or

Mount-o rw, remount/dev/block/mmcblk0p12/System

5. Run mount again to check whether the permission is successfully modified.