I just pulled the current master and flashed it to the board. Afterwards, I tried to remount /system as usual:
adb root
adb remount
However, this gives me the error:
“remount of the / superblock failed: Permission denied”
When I run “mount -o rw,remount /system” from the adb shell, I get “/system not in /proc/mounts”.
As I found on Stackoverflow, I also tried
adb root
adb disable-verity
adb reboot
...
adb root
adb remount
but this gives the same result. What is going on here?
I haven’t got to current master yet, but have you tried specifying the path to what you are remounting?
i.e.
mount -o remount,rw /path/to/system/partition /system
Also, what is the output of
mount
?
Anything jump out the kmsg when you get the permission denial?
In kmsg, I get: EXT4-fs (sdd11): re-mounted. Opts: (null)
mount prints:
tmpfs on /dev type tmpfs (rw,seclabel,nosuid,relatime,mode=755)
devpts on /dev/pts type devpts (rw,seclabel,relatime,mode=600,ptmxmode=000)
proc on /proc type proc (rw,relatime)
sysfs on /sys type sysfs (rw,seclabel,relatime)
selinuxfs on /sys/fs/selinux type selinuxfs (rw,relatime)
tmpfs on /mnt type tmpfs (rw,seclabel,nosuid,nodev,noexec,relatime,mode=755,gid=1000)
/dev/block/sdd10 on / type ext4 (rw,seclabel,nodev,relatime,block_validity,delalloc,barrier,user_xattr)
/dev/block/sdd11 on /vendor type ext4 (rw,seclabel,relatime,block_validity,delalloc,barrier,user_xattr)
none on /acct type cgroup (rw,nosuid,nodev,noexec,relatime,cpuacct)
none on /dev/memcg type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
none on /dev/stune type cgroup (rw,nosuid,nodev,noexec,relatime,schedtune)
none on /config type configfs (rw,nosuid,nodev,noexec,relatime)
none on /dev/cpuctl type cgroup (rw,nosuid,nodev,noexec,relatime,cpu)
none on /dev/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset,noprefix,release_agent=/sbin/cpuset_release_agent)
cg2_bpf on /dev/cg2_bpf type cgroup2 (rw,nosuid,nodev,noexec,relatime)
bpf on /sys/fs/bpf type bpf (rw,nosuid,nodev,noexec,relatime)
pstore on /sys/fs/pstore type pstore (rw,seclabel,nosuid,nodev,noexec,relatime)
/sys/kernel/debug on /sys/kernel/debug type debugfs (rw,seclabel,relatime,mode=755)
tracefs on /sys/kernel/debug/tracing type tracefs (rw,seclabel,relatime)
/dev/block/sdd13 on /data type ext4 (rw,seclabel,noatime,discard,noauto_da_alloc,data=ordered)
tmpfs on /storage type tmpfs (rw,seclabel,nosuid,nodev,noexec,relatime,mode=755,gid=1000)
adb on /dev/usb-ffs/adb type functionfs (rw,relatime)
mtp on /dev/usb-ffs/mtp type functionfs (rw,relatime)
ptp on /dev/usb-ffs/ptp type functionfs (rw,relatime)
/data/media on /mnt/runtime/default/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=1015,multiuser,mask=6,derive_gid,default_normal)
/data/media on /storage/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=1015,multiuser,mask=6,derive_gid,default_normal)
/data/media on /mnt/runtime/read/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=9997,multiuser,mask=23,derive_gid,default_normal)
/data/media on /mnt/runtime/write/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=9997,multiuser,mask=7,derive_gid,default_normal)
I found out that I can run
mount -o rw,remount /dev/block/platform/soc/ff3b0000.ufs/by-name/system`
which gives me write access to /system. But it would be much nicer to be able to use adb remount.
Wow, /system mount is not even showing in there. That’s wild.
adb shell mount -o rw,remount /dev/block/platform/soc/ff3b0000.ufs/by-name/system
Is there anything we can do about it, except for defining an alias for that command?
The best solution is actually just to leave the system partition alone. The vendor partition still responds to the adb remount command, and makes a lot more sense to mangle than the system partition, which in theory should be device-independent.
