attaching to android native app with gdb closes app on device - android

I am attempting to debug my native app compiled with ndk-r6. When I attempt to run ndk-gdb to attach the debugger to the process, the app quits on the device. I am stumped. Can anyone shed some light on this for me please?
Here is a log of a run of the gdb process: http://pastebin.com/qTCR7mF2
This is all I get out of logcat:
I/ActivityManager(10006): Process com.gmail.whittock.tom.clockwork (pid 11460) has died.
I/WindowManager(10006): WIN DEATH: Window{4083aa18 com.gmail.whittock.tom.clockwork/com.gmail.whittock.tom.Util.NativeActivity paused=false}
I/WindowManager(10006): WIN DEATH: Window{4085d8d0 SurfaceView paused=false}
I/WindowManager(10006): Setting rotation to 0, animFlags=1
I/ActivityManager(10006): Config changed: { scale=1.0 imsi=234/10 loc=en_GB touch=3 keys=1/1/2 nav=1/1 orien=1 layout=34 uiMode=17 seq=31 themeResource=null}
EDIT:
and this is my gdb.setup file:
$ cat libs/armeabi-v7a/gdb.setup
set solib-search-path C:/Users/Tom/dev/android/Clockwork/obj/local/armeabi-v7a
directory C:/Users/Tom/dev/android/ANDROI~2/platforms/android-5/arch-arm/usr/include C:/Users/Tom/dev/android/ANDROI~2/sources/cxx-stl/stlport/stlport C:/Users/Tom/dev/android/ANDROI~2/sources/cxx-stl/system/include C:/Users/Tom/dev/android/modules/box2d C:/Users/Tom/dev/android/Clockwork/jni
all paths in there look correct to me, but perhaps it's the use of the dos-compatibility versions of filenames that's causing the issue?!
EDIT2: This is the other gdb.setup file:
$ cat obj/local/armeabi-v7a/gdb.setup
file C:/Users/Tom/dev/android/Clockwork/obj/local/armeabi-v7a/app_process
target remote :5039
file C:/Users/Tom/dev/android/Clockwork/obj/local/armeabi-v7a/app_process
target remote :5039
file C:/Users/Tom/dev/android/Clockwork/obj/local/armeabi-v7a/app_process
target remote :5039

I finally found the issue.
ndk-gdb HAS HAS HAS to have NDK_DEBUG=1 environment variable set, otherwise the NDK_APP_GDBSETUP variable gets set to blank due to make believing that the app isn't debuggable (being too damn smart for its own good)
This then causes the gdb.setup file to get corrupted, because a copy command fails and we start appending to the end of anything that is already there. This is why the same command pair is repeated 3 times in obj/local.../gdb.setup.
You have no idea how much pain this has caused me. Hopefully someone else will have an easier time if they read this.

Step by step instructions to setting up GDB on eclipse Your GDB configuration is probably borked. Rather than trying to diagnose the problem, try following those steps and see if that fixes your problem.

Related

Android Port bootloop due to non updatable apex or boringssl checks

I am building LineageOS 18.1 for tecno kd7. I have system, system_ext, product & vendor paritions. The rom port I built is having a boot loop.
Here is the last_kmsg
What is causing the boot loop?
I am suspecting these lines
[ 1.802608] (0)[354:apexd]apexd: This device does not support updatable APEX. Exiting
[ 2.352523] (0)[1:init]reboot: Restarting system with command 'boringssl-self-check-failed'
I just need direction on what I need to what is causing the phone to bootloop
I also faced the same issue. The boringssl-self-test binary is using incorrect libcrypto.so library.
You can run the boringssl-self-test with strace and check for the issue.
In file : external/boringssl/selftest/boringssl_self_test.rc
service boringssl_self_test64_vendor /system/bin/strace -tt /vendor/bin/boringssl_self_test64
setenv BORINGSSL_SELF_TEST_CREATE_FLAG true # Any nonempty value counts as true
#reboot_on_failure reboot,boringssl-self-check-failed
stdio_to_kmsg
seclabel u:r:vendor_boringssl_self_test:s0

Android's Logcat spammed with selinux avc denials on tmpfs, type 1400 by kworker/kernel

I am getting my android's logcat spammed with these warnings.(rooted with magisk)
10-15 22:02:29.039 12944 12944 W kworker/0:4: type=1400 audit(0.0:87190): avc: denied { read write } for name="sde73" dev="tmpfs" ino=28978 scontext=u:r:kernel:s0 tcontext=u:object_r:oem_device:s0 tclass=blk_file permissive=0
I was looking into the following doc to see how could i fix this issue, but cannot figure it out.
https://source.android.com/security/selinux/device-policy
https://source.android.com/security/selinux/validate
https://source.android.com/security/selinux/concepts
https://source.android.com/security/selinux/implement
https://gist.github.com/msfjarvis/ec52b48eb2df1688b7cbe32bcd39ee5f
https://android.stackexchange.com/questions/207484/how-to-fix-selinux-avc-denied-errors-when-launching-dnscrypt-as-init-d-script
https://source.android.com/security/selinux/customize#android-o
https://android.stackexchange.com/questions/218911/how-to-add-selinux-policy-on-a-user-debug-rom-that-has-split-policy-scheme
https://android.stackexchange.com/questions/214839/how-to-run-an-android-init-service-with-superuser-selinux-context
https://topjohnwu.github.io/Magisk/tools.html#magiskpolicy
https://topjohnwu.github.io/Magisk/details.html#magisk-booting-process
https://topjohnwu.github.io/Magisk/guides.html#boot-scripts
I looked in /dev, but i do not have anything similar.
android# ls -l /dev/ | grep sd
#returns nothing
The inode resolves to this file:
find /sys -xdev -inum 28978
/sys/firmware/devicetree/base/__symbols__/sb_7_tx
However on next reboot resolves to other file but the errors are always related to one single inode.
I suppose i should add this rule in a .te file
allow kernel oem_device:blk_file {read write};
adb pull /sys/fs/selinux/policy
adb logcat -b all -d | audit2allow -p policy
#this confirms the rule
I found some related files to selinux in this dump:
https://git.rip/dumps/oneplus/oneplus7tpro/-/find_file/hotdog-user-10-QKQ1.190716.003-2009281542-release-keys
but i am not very sure where should i add the rule..possibly somewhere in /vendor/etc/selinux..
Does anyone know which are the steps to fix these warnings and maybe further dig into the investigation why they occur in the first place?
Thanks
The reason why it shows is straightforward from the error. kernel is trying to read/write a blk_file labeled with oem_device type.
At this point you have couple of options:
Add allow rule if you want to allow the access to happen.
Add dontaudit rule, if you want to just suppres the log. See
here
The rule should be added into kernel.te.
Usually these custom things go into device/XXXXXX, depending on the vendor. For example in my tree, for a rockchip device, I'd modify /device/rockchip/common/sepolicy/vendor/kernel.te
To rebuild policies you would:
source build/envsetup.sh
lunch-yourTarget
mmm system/sepolicy
And to flash them into the system ( if you're userdebug and can remount it ):
adb root
adb remount
adb push out/target/product/YOUR_DEVICE/vendor/etc/selinux /vendor/etc/
adb push out/target/product/YOUR_DEVICE/system/etc/selinux /system/etc/
adb shell sync
adb reboot
If you can't push them, you'll need to rebuild and flash the system
I managed to fix the warnings with this command:
magiskpolicy --live 'allow kernel oem_device blk_file {read write open}'
'open' right was also granted because another warning related to it would appear after allowing only read/write.
Still I cannot understand:
why is kernel trying to access this
what exactly is trying to access
shouldn't magisk take care of the selinux policies related to such low level grants such as kernel
not sure how can i make this fix permanent (to persist upon reboot). From my research it looks like i have to modify a certain file in boot.img, repack it and push it back to android.
On this page:
https://topjohnwu.github.io/Magisk/tools.html
it's specified a tool magiskboot which should be used for such patching but I do not have it.
A tool to unpack / repack boot images, parse / patch / extract cpio, patch dtb, hex patch binaries, and compress / decompress files with multiple algorithms.
I will come back with any findings..
UPDATE:
I managed to permanently add the fixes at boottime with a post-fs-data script that runs during booting process. It might not be 100% fix because, the boot image should be patched instead so that magiskinit loads the policies even before init is executed, but it still however fixes the warnings in logcat after the boot process ended
REF:
https://topjohnwu.github.io/Magisk/details.html#magisk-booting-process
https://topjohnwu.github.io/Magisk/guides.html#boot-scripts
su -
cd /data/adb/post-fs-data.d
touch fix_selinux.sh
chmod +x fix_selinux.sh
vi fix_selinux.sh #add this line (and any other rules you need):
/sbin/magiskpolicy --live 'allow kernel oem_device blk_file {read write open}'

recipe for target 'ninja_wrapper' failed / flex core dumps

First time android builder here. I used to do a lot of roll your own back on FreeBSD in the day. Getting back into geekdom with android.
I am trying to build android-7.0.0_r14 for the Nexus 6 NBD90Z to run under emulation. I plan to eventually build for my actual phone and this config is pretty close. I am building on ubuntu 18.04 LTS which is newer than what the docs recommend. Maybe that is a bit adventurous.
Here is what I get when I run make.
... snip
build/core/base_rules.mk:316: warning: ignoring old commands for target
out/target/product/shamu/system/lib/soundfx/libqcomvoiceprocessing.so'
Starting build with ninja
ninja: Entering directory.'
ninja: warning: multiple rules generate out/target/product/shamu/system/etc/gps.conf. builds involving this target will not be correct; continuing anyway [-w dupbuild=warn]
[ 0% 1/35600] Lex: libaidl-common <= system/tools/aidl/aidl_language_l.ll
FAILED: /bin/bash -c "prebuilts/misc/linux-x86/flex/flex-2.5.39 -oout/host/linux-x86/obj/STATIC_LIBRARIES/libaidl-common_intermediates/aidl_language_l.cpp system/tools/aidl/aidl_language_l.ll"
flex-2.5.39: loadlocale.c:130: _nl_intern_locale_data: Assertion `cnt < (sizeof (_nl_value_type_LC_TIME) / sizeof (_nl_value_type_LC_TIME[0]))' failed.
Aborted (core dumped)
ninja: build stopped: subcommand failed.
build/core/ninja.mk:148: recipe for target 'ninja_wrapper' failed
make: *** [ninja_wrapper] Error 1
A core dump for flex was not produced in spite of the error message given.
out/host/linux-x86/obj/STATIC_LIBRARIES/libaidl-common_intermediates/aidl_language_l.cpp does not exist. That entire folder is empty. It would seem that something is not downloading/copying the aidl_language_l.cpp.
Any ideas on what I might have messed up?
I am still a little confused at the complexity of git/repo/make/ninja/soong/lunch to conduct a build. It is likely that I missed something obvious.
Thanks,
Jason C. Wells
Just replace your make by export LC_ALL=C make or put the export in your .bashrc
After I looked at this a little closer I realized the prebuilt prebuilts/misc/linux-x86/flex/flex-2.5.39 would dump core with no arguments. I created a soft link to /usr/bin/flex. Compilation seems to be proceeding.
I haven't answered why the prebuilt was dumping. My goal is to compile android, not troubleshoot the tools.
I performed Snorky's steps. I deleted my output directory for libaidl-common_intermediates. I deleted my soft link and restored the android tree version of flex. I re-ran make at the top of the local repo. The build proceeded past the error above and stopped at a new error. It appears that Snorky's answer worked.
Doh! I'm new so S.O. didn't give credit for my upvote.

Add native service to aosp

I am trying to add a native service written in C++ to the AOSP build.
The first thing I did was to create a native service and client to the AOSP build.
This worked as expected. I could start the service within an adb shell and call it via binder on a adb shell.
The trouble started when I wanted to start my service with init.
I added a .rc file to my build
service myp /system/bin/myp_service
class main
This did the the trick so that init tried to start it but it failed because of SELinux policies.
So I added a file_contexts to my device tree and added:
/system/bin/myp_service u:object_r:myp_exec:s0
Next I added a myp.te file and added:
type myp, domain;
type myp_exec, exec_type, file_type;
type myp_service, service_manager_type;
init_daemon_domain(myp)
net_domain(myp)
binder_use(myp)
binder_service(myp)
add_service(myp, myp_service)
binder_call(myp, binderservicedomain)
binder_call(myp, appdomain)
allow myp myp_service:service_manager add;
And finally I added a service_contexts file with:
myp u:object_r:myp_service:s0
This finally made my service successfully start at boot time.
Unfortunalty I cannot use binder against this service. When I try to connect to the service with my client the call
defaultServiceManager()->getService(String16("Demo"))
returns a null pointer.
I cannot find any hints in the dmesg.
So I assume I am still missing something for the SElinux but I have no clue what I am missing.
If I shutdown the SELinux with setenforce and restart the service then it works fine.
Can anyone give me a hint what I am missing for SELinux or where I can get more information about which policy blocked something?
You could see the denials like this:
adb logcat | grep "SELinux : avc" > /tmp/logs
Get sepolicy current file. (Can be taken from device this way adb pull sepolicy.
Using audit2allow (located in AOSP source code: external/selinux/prebuilts/bin/audit2allow or in SDK tools. Do this: cat /tmp/logs | .external/selinux/prebuilts/bin/audit2allow -p sepolicy
The audit2allow tool will tell you what permission you are missing for the logcat extracted and the current sepolicy file, watch-out because you could need to do this several times since fixing some permissions will show the next ones required.
If you have a userdebug kind of build you could get setenforce 0, logcat with it and all the denials will be in logcat even if you will be permited to do the operation desired. This will leave the audit2allow iterations required in 1.
For anyone who came across this problem, please make sure your service_contexts file is successfully merged with stock service_contexts file. If you're building your service for Android O or later, please put this file inside a folder and refer to it in your Makefile by BOARD_PLAT_PRIVATE_SEPOLICY_DIR1. And you don't need to add allow myp default_android_service:service_manager add if the build system does pick up your service_contexts.
Also, about the domain.te violation problem, you probably want to attach one of the coredomain or appdomain attribute to your domain 2 with typeattribute <your_domain> <attribute>;.
Finally, please double check the following built files to make sure you don't leave any sepolicy configurations out in the final build:
$(AOSP_ROOT)/out/target/product//obj/ETC/file_contexts.bin_intermediates/file_contexts.*
$(AOSP_ROOT)/out/target/product/potter/obj/ETC/plat_service_contexts_intermediates/service_contexts.*
$(AOSP_ROOT)/out/target/product/potter/obj/ETC/sepolicy_neverallows_intermediates/policy.conf

Kernel Configuration - Nexus Platform join failed

I am doing kernel configuration for ICS. I needed to enable Posix message queue as it is required in one of our applications. But enabling this option resulted in error. The make was successfull. But the image could not be loaded. The dmesg was:-
disagrees about version of symbol module_layout.
init: untracked pid 2038 exited.
logcat :-
mknod : '/dev/nexus_proxy' failed
NEXUS_Platform_Join [CONSTRUCTOR] failed.
Looks like you rebuilt only the kernel.
You need to build any kernel-modules (*.ko files) and
update them onto the filesystem.
Here is a detailed discussion on the disagrees about version of symbol error.

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