adb shell su works but adb root does not

问题:

I rooted my unlocked Galaxy S3 (SGH-T999)

Now, I'm trying to run adb root from Windows Command Prompt, however, I'm getting adbd cannot run as root in production builds error. So, the very first thing I checked was whether my phone was really rooted?

So I tried the following:

Open Command prompt

$adb devices // lists my device
$adb shell //goes to shell
$su // opens a 'SuperSu' prompt on my phone and I 'Grant' permission
# // Before following the rooting instructions, I was getting 'no su command found' in the previous step. So, I believe my phone is ROOTED. **Correct me if I'm wrong.**

However, when I do adb root, I get adbd cannot run as root in production builds error. So, I thought, I might have to do some additional stuff beyond what I did above. I tried all the solutions in the following SO questions:

• Launch a script as root through ADB
• adb remount permission denied, but able to access super user in shell -- android
• Unable to run 'adb root' on a rooted Android phone

None of the above worked for me. All they do is give the ROOT access INSIDE of SHELL. I want adb root to work so that I can execute various adb commands WITHOUT going into shell.

回答1:

In some developer-friendly ROMs you could just enable Root Access in Settings > Developer option > Root access. After that adb root becomes available. Unfortunately it does not work for most stock ROMs on the market.

回答2:

By design adb root command works in development builds only (i.e. eng and userdebug which have ro.debuggable=1 by default). So to enable the adb root command on your otherwise rooted device just add the ro.debuggable=1 line to one of the following files:

/system/build.prop
/system/default.prop
/data/local.prop

If you want adb shell to start as root by default - then add ro.secure=0 as well.

Alternatively you could use modified adbd binary (which does not check for ro.debuggable)

From https://android.googlesource.com/platform/system/core/+/master/adb/daemon/main.cpp

#if defined(ALLOW_ADBD_ROOT)
// The properties that affect `adb root` and `adb unroot` are ro.secure and
// ro.debuggable. In this context the names don't make the expected behavior
// particularly obvious.
//
// ro.debuggable:
//   Allowed to become root, but not necessarily the default. Set to 1 on
//   eng and userdebug builds.
//
// ro.secure:
//   Drop privileges by default. Set to 1 on userdebug and user builds.

回答3:

I have a rooted Samsung Galaxy Trend Plus (GT-S7580).

Running 'adb root' gives me the same 'adbd cannot run as root in production builds' error.

For devices that have Developer Options -> Root access, choose "ADB only" to provide adb root access to the device (as suggested by NgaNguyenDuy).

Then try to run the command as per the solution at Launch a script as root through ADB. In my case, I just wanted to run the 'netcfg rndis0 dhcp' command, and I did it this way:

adb shell "su -c netcfg rndis0 dhcp"

Please check whether you are making any mistakes while running it this way.

If it still does not work, check whether you rooted the device correctly. If still no luck, try installing a custom ROM such as Cyanogen Mod in order for 'adb root' to work.

回答4:

You need to replace the adbd binary in the boot.img/sbin/ folder to one that is su capable. You will also have to make some default.prop edits too.

Samsung seems to make this more difficult than other vendors. I have some adbd binaries you can try but it will require the knowledge of de-compiling and re-compiling the boot.img with the new binary. Also, if you have a locked bootloader... this is not gonna happen.

Also Chainfire has an app that will grant adbd root permission in the play store: https://play.google.com/store/apps/details?id=eu.chainfire.adbd&hl=en

Lastly, if you are trying to write a windows script with SU permissions you can do this buy using the following command style... However, you will at least need to grant (on the phone) SU permissions the frist time its ran...

adb shell "su -c ls" <-list working directory with su rights. adb shell "su -c echo anytext > /data/test.file"

These are just some examples. If you state specifically what you are trying to accomplish I may be able to give more specific advice

-scosler

回答5:

I use for enter su mode in abd shell

adb shell "su"

回答6:

I ran into this issue when trying to root the emulator, I found out it was because I was running the Nexus 5x emulator which had Google Play on it. Created a different emulator that didn't have google play and adb root will root the device for you. Hope this helps someone.

回答7:

If you really need to have ADB running as root, the quickest and easiest way is to install Android Custom ROMs and the most popular is CyanogenMod for it has the Root Access options in developer options menu where you can choose to give root access to apps and ADB. I used CM before but since it wasn't developed anymore, I tried looking for some solutions out there. Although CyanogenMod is still a good alternative because it does not have bloatware.

One alternative I found out from a friend is using adbd insecure app which you could try from here: https://forum.xda-developers.com/showthread.php?t=1687590. In my case, it works perferct with an Android custom kernel, but not with the Android stock ROM (vanilla android only). You may try other alternatives too like modifying boot.img of the Android ROM.