1. logcat.
2. This issue must be posted in termux-packages repo, not in termux-tools.

Yikes, I just noticed that this update took my phone from Android 13 to Android 14 ????

I think you should just do pkg up, update should fix this.

Thanks for the quick reply, I just tried pkg up and seems like no updates,
All packages are up to date.

chmod -w /data/data/com.termux/files/usr/share/dex/ecj.jar

Also could you please point me in the right direction to collect logcat data. I don't know how to do it. I tried setting the level to verbose on Termux and got a bunch of output, but honestly don't know what I'm doing, poking in the dark 😏

chmod -w /data/data/com.termux/files/usr/share/dex/ecj.jar

Huh ? How's that supposed to help. I only have a problem with running classes.
ecj and dx have already run. I am now just trying to run a simple class.

Anyway to collect info on the Abort issue ?

1. Run logcat -d > log.txt in termux.
2. Move log.txt to sdcard and pin to post.

Huh ? How's that supposed to help. I only have a problem with running classes.

#16255

Any news on this?

1. Run logcat -d > log.txt in termux.
2. Move log.txt to sdcard and pin to post.

Thank you 🙏, I collected the data
But don't know how to interpret... Might spend a little time investigating. Seems to complain about lack of image, etc and eventually aborts

Post it and I will tell you why that happens.

Post it and I will tell you why that happens.

I think you are absolutely right. I read about the issue as you mentioned above. Will take a small break and try to make classes readonly
logcat.txt

Your error is dalvikvm: Attempt to load writable dex file: /data/data/com.termux/files/home/work/hello2/classes.dex. Make it non-writable too.

Your error is dalvikvm: Attempt to load writable dex file: /data/data/com.termux/files/home/work/hello2/classes.dex. Make it non-writable too.

Twaik can't thank you enough for guiding me through this. It worked
👍👍👍

We should patch ecj to do this automatically.

We should patch ecj to do this automatically.

I also use a copy of Sun's jar tool to produce my jar files. Experimenting now to see if
A. classes within jar r/w matters
B. Jar itself r/w matters
Will comment soon.

Again thanks a million for pointing me in the right direction, I was already going down hell path getting a tar of dalvikvm and bin/lib64/javalib from my Android 13 phone, lol 😂

Ok, I experimented a bit.
If CLASSPATH and/or the -cp argument point to any files that are not write protected, dalvikvm will Abort.
So any .dex or .jar files in -cp or CLASSPATH will do. When a jar/dex file is created the individual write attributes of the elements in the jar/dex file don't matter. The only thing that matters is that the output file or jar and dex as seen by dalvikvm must be read only.

We should patch ecj to do this automatically.

See above, I ran a few tests as I was modifying my build process and I had to ensure that all jar files (which contain .dex files) and individual.dex files that were in -cp argument or CLASSPATH as een by dalvikvm MUST be READ-ONLY.

So I am not sure that ecj is culprit.

dx --dex which used to transcode .class to dex or '.jar files contained .class files' to a dex-output is culprit. This is because it's the only way to prepare an object that is usable by dalvikvm.

One could also include multiple.dex files in a jar and use that in -cp/CLASSPATH but also the jar utility must ensure that the produced output is READ-ONLY. So jar utilities are culprit

I hope this helps.... ecj is only converting .java to .class which are unusable as is.

Ok, I experimented a bit.

It was no need to do that. #16255

Ok, I experimented a bit.

It was no need to do that. #16255

They are talking about am utility.
In general many users, myself included, have a lot of java code in Termux as well as Java servers. I don't use APKs

So I needed to modify my own java build environment which is a mix of jar and dex files

Quote:

Android 14 requires that all dynamically loaded dex files are read-only to prevent security issues.

Quote:

Android 14 requires that all dynamically loaded dex files are read-only to prevent security issues.

I agree 100%, but the question is what produces the artifacts that are in -cp or CLASSPATH.
The answer is jar and dx -- dex output=...

Ok, now I see that we download .jar and do not build it from source. Maybe we should make it run with openjdk-17? @licy183 @truboxl ?

That is the problem: https://cs.android.com/android/platform/superproject/+/dd6fde63193fda968440fc0a4cd9ccee5d282ab0:art/runtime/native/dalvik_system_DexFile.cc;l=381

Android checks if current uid is 0 (root), 1000 (system) or 2000 (shell) AND if apk has write access.
Possible solution: make a little library which overrides regular access function which will always report no write access or override regular getuid which will always report 2000 (shell) and put this library to LD_PRELOAD in dalvikvm starting script.

@licy183 @truboxl should we create a wrapper script for dalvikvm for overriding W^X behaviour or we should just close the issue?

https://github.com/termux/termux-tools/blob/57c4adf65069cf17567330d7c00adc5b98e15419/scripts/dalvikvm.in#L13

Oh, so we should just create a library for that and add it to LD_PRELOAD, right?
@sylirre @Grimler91 @2096779623 pinging you because you commited to the repo.