Unable to run Redroid on Arch Linux

[kebugcheckex]

Summary

Redroid crashes due to not able to find /dev/binder on Arch Linux with zen kernel, despite that zen kernel has binder builtin.

Context

I'm trying to run Redroid in Arch Linux with the zen kernel. It has binder and ashmem modules built into the kernel (not as loadable kernel modules). I confirmed that the output of the following commands are expected

$ grep binder /proc/filesystems 
nodev   binder
$ grep ashmem /proc/misc
124 ashmem

Binderfs is present in /dev

$ ls -l /dev/binderfs
total 0
crw------- 1 root root 238, 0 Oct  4 14:40 binder-control

However, redroid is crash-looping due to not able to open /dev/binder

...
10-04 21:47:11.646    35    35 E ProcessState: Binder driver /dev/binder is unavailable. Using /dev/binder instead.
10-04 21:47:11.646    35    35 W ProcessState: Opening '/dev/binder' failed: No such file or directory
10-04 21:47:11.646    35    35 F ProcessState: Binder driver '/dev/binder' could not be opened.  Terminating.
10-04 21:47:11.646    35    35 F libc    : Fatal signal 6 (SIGABRT), code -1 (SI_QUEUE) in tid 35 (servicemanager), pid 35 (servicemanager)
...

Full Logcat output can be found here.
dmesg messages are similar so I omit the details here.

I manually built a kernel with the appropriate configs and it works. The only difference between zen-kernel and my custom built is that zen kernel is built with
zen kernel is built with

CONFIG_ANDROID_BINDER_DEVICES=""

while my build uses

CONFIG_ANDROID_BINDER_DEVICES="binder,hwbinder,vndbinder"

Not sure if this is causing the problem. I posted a while back in the other repo. I'm posting here to have more visibility and potentially more help.

Any one has successfully run Redroid on Arch Linux (including Manjaro, etc.)? Please share your config/method. Thanks.

[zhouziyang]

currently, binder,hwbinder,vndbinder is required either via kernel build config or kernel module params (like ubuntu 20.04+)
I will enhance the binder device allocation process in redroid instance (create binder device if not pre-allocated).

[kebugcheckex]

How can I help here?

[zhouziyang]

@kebugcheckex FYI, I will create new binary, and get executed after mount binderfs in init.rc / init.redroid.rc. this binary will check binder existance, and allocate new if not exist. vendor_redroid, device_redroid are involved.

[minhducsun2002]

@kebugcheckex I think you can try adding stuff to the command line like I did :

$ cat /proc/cmdline 
initrd=\intel-ucode.img initrd=\initramfs-linux-zen.img root=UUID=[redacted] binder.devices=binder,hwbinder,vndbinder,anbox-binder,anbox-hwbinder,anbox-vndbinder```

[DavidVentura]

even on ubuntu 21.04, mounting binderfs only has binder-control in it.

/proc/cmdline shows
binder.devices=binder,hwbinder,vndbinder,anbox-binder,anbox-hwbinder,anbox-vndbinder

and even running modprobe with the flags modprobe binder_linux devices=binder,hwbinder,vndbinder does not add the devices.

for me, the container crash-loops logging

[ 6279.683665] DEBUG: Abort message: 'Binder driver '/dev/binder' could not be opened.  Terminating.'

among other things.

[zhouziyang]

not tested on Arch. But it should work in ubuntu 20.04 / ubuntu 21.04 with just modprobe binder_linux devices=binder,hwbinder,vndbinder (or some other module auto-load mechanism /etc/modules-load.d/).

[DavidVentura]

it is currently not the case for me on 21.04, on kernel 5.11.0-40 I have the same output as @kebugcheckex and I can provide any logs you need to debug

[zhouziyang]

can you check with the following command?

# cat /sys/module/binder_linux/parameters/devices
binder,hwbinder,vndbinder
# uname -a

[DavidVentura]

$ cat /sys/module/binder_linux/parameters/devices

$ cat /proc/cmdline                     
BOOT_IMAGE=/boot/vmlinuz-5.11.0-40-generic ro quiet splash binder.devices=binder,hwbinder,vndbinder,anbox-binder,anbox-hwbinder,anbox-vndbinder vt.handoff=7
$ lsmod | grep binder
binder_linux          204800  0
$ uname -a
Linux david 5.11.0-40-generic #44-Ubuntu SMP Wed Oct 20 16:16:42 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

[zhouziyang]

redroid/redroid:11.0.0-latest docker image get updated. please try the new image, it will allocate binder devices if needed.
other version of redroid images will get update soon.

[DavidVentura]

Same outcome (the new image got pulled); I even added a -v /dev/binder:/dev/binder after the failure to see if that'd work but it did not.

docker run -itd --rm --memory-swappiness=0 --privileged     --pull always     -v ~/data:/data -v /dev/binder:/dev/binder     -p 5555:5555     redroid/redroid:11.0.0-latest

and my host's /dev/binder still only had binder-control

[zhouziyang]

You should not mount binder from your host (-v /dev/binder:/dev/binder).
try

docker run -itd --rm --memory-swappiness=0 --privileged \
    --pull always \
    --name redroid11 \
    -v ~/data:/data \
    -p 5555:5555 \
    redroid/redroid:11.0.0-latest

try to collect debug logs if still not work

docker exec -it redroid11 -- sh
# inside container
logcat
ls -al /dev/binderfs
/vendor/bin/binder_alloc

[DavidVentura]

130|3a96063df8ca:/ # ls -al /dev/binderfs
total 0
drwxr-xr-x  3 root root        0 2022-01-06 17:17 .
drwxr-xr-x 30 root root     4820 2022-01-06 17:17 ..
crw-rw-rw-  1 root root 239,   4 2022-01-06 17:17 binder
crw-------  1 root root 239,   3 2022-01-06 17:17 binder-control
drwxr-xr-x  3 root root        0 2022-01-06 17:17 binder_logs
crw-rw-rw-  1 root root 239,   5 2022-01-06 17:17 hwbinder
crw-rw-rw-  1 root root 239,   6 2022-01-06 17:17 vndbinder
3a96063df8ca:/ # ls -al /vendor/bin/binder_alloc                                                                                                            
-rwxr-xr-x 1 root shell 7040 2022-01-06 14:11 /vendor/bin/binder_alloc

3a96063df8ca:/ # ls -lh /dev/binder                                                                                                                         
total 0
crw------- 1 root root 239,   7 2022-01-06 17:17 binder-control

The logcat log still complains about /dev/binder not being openable (attached)
out.txt