Custom gdb 7.4.1 for Android: cannot access memory - android

I've built the gdb 7.4.1 for Android (applied Android patches from ndk-r8 and configured it for arm-linux-androideabi). It works fine on some devices, but on some other it refuses to set breakpoints reporting "cannot access memory".
I used the original gdbserver from the NDK assuming that the protocol is compatible.
Has anyone run into similar problems? Do I need to build the gdbserver from 7.4.1 sources as well? Or am I missing some external patches?

Just solved it. Apparently, the gdbserver provided with Android NDK r8 is not fully compatible with gdb 7.4.1. Building gdbserver from sources and replacing the NDK one solves the problem completely.

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How to get libssl.so and libcrypto.so from apk

So i am try to build openSSL into my qt android app. and to all my efforts from using precompiled binary to installing ubuntu 18 and still failing i am getting desperate.
I have read from this thread:
QT + OpenSSL + Android
that i can get them from ANY existing apk, so how do i extract it from the apk? Because i do not find it in the android ndk and sdk. if its only selected apk, what program do i use indor for me to see it.
im using Qt 5.11 on windows, but i have linux OS too if needed :) Thank you!
I've built OpenSSL for android a few months ago, with zero issues. Just follow this guide for Linux:
export ANDROID_NDK_ROOT="/home/dev/android-ndk-r12b"
SR="$ANDROID_NDK_ROOT/platforms/android-16/arch-arm"
BR="$ANDROID_NDK_ROOT/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi-"
RANLIB="$BR"ranlib CC="$BR"gcc ./Configure android-armeabi --prefix=$SR/usr --sysroot=$SR
ANDROID_DEV=$SR/usr make
make install
Obviously, you will have to replace the paths with your own depending on where and what NDK version you install, and you will already have downloaded and extracted the OpenSSL source. Also, keep in mind that Qt doesn't seem to work with the latest and "greatest" android toolchains. In fact, android has already switched to llvm, but for Qt you will need to use the older gcc toolchains.
You can use this script to build libcrypto.
There are many prebuilt binaries you can get online, without having to rummage about in apk files, for example this repo has openssl libcrypto for a bunch of platforms, including android.
Don't know where you got the idea that you could get the libs from any apk file, obviously, it has to be a package from an application that incorporates those libraries for dynamic linking.
Last but not least, if you still plan on getting pre-compiled binaries, keep in mind they have to be built with a version that is compatible with your compiler. Which is why it is best to build the libs yourself, with the same toolchain you are using for your application. There is also the danger of getting "bad" libs from an unknown source, they might be outdated or tampered with.
You can open them by simply changing their extension to ".zip" :) will update if i can find apps that has these files.
PS: No all apk has libcrypto.so and libssl.so.

Installing NDK (arm-linux-androideabi-gcc) on Android (Remix OS)

I'm trying to install some python packages (pillow) for QPython on Remix however I get the error that arm-linux-androideabi-gcc does not exist.
I googled and I think I need NDK, however looking at the website (https://developer.android.com/ndk/downloads/index.html) I couldn't find a way to do this on android.
Any help is much appreciated, thank you!
Installing the NDK on Android? As in running the NDK compilers on an Android device? We don't support Android as a host OS for the NDK.
Check out AIDE android ide from the Google playstore
Despite Dan's answer, which I respect. It's not entirely accurate. The Android ndk build system doesn't allow for for host to be set to the $TARGET_ARCH, but building it manually in much the same way you would for any custom toolchain is entirely possible.
I should note that I have only done this for gcc, and have not attempted to do so with clang.
From Googles ndk toolchain repo just take the essentials needed, gcc, binutils, gmp, mpfr, etc and set your host and target to the ndk toolchain gcc. Use the ndk sysroot as build-sysroot, and then just add your compiler flags and with a little fiddling you should get it.
Id be happy to post more, it's been a project of mine to build Android on Android, also i highly recommend adding static versions of the ndk libs, as the android system doesn't have a c++ lib, and a few others. You may have to build some manually using aosp build system
I built it with stage-one flags so that the binaries would be static, as you never know when android might remove a lib that your toolchain depends on.
I encourage you to try, as an added benefit you will then he able to build many useful android native binaries that usually aren't available without editing the aosp source. Also having the ability to build binaries on the fly is very useful

elf32-littlearm symbol format unrecognized debugging Native Android code

I'm trying to debug some native Android code built through the NDK. Unfortunately, when I launch the process under the debugger from Eclipse I get an error
I'm sorry, Dave, I can't do that. Symbol format `elf32-littlearm' unknown.
The code is compiled for ARM thumb so the symbol format makes sense. However, using Google's bundled ADT for Eclipse should work? Do I need to specify a specific version of GDB to use?
To note, the code runs fine without trying to debug.
I'm running on Windows 7 64 bit with NDK release 10.
After some searching it looks like it is a bug with the GDB shipped with the NDK r10 toolchain. See https://code.google.com/p/android/issues/detail?id=74371. The download linked from that bug seems to work for me.

Android NDK with Qt not able to locate header files

I am trying to deploy a Qt app to an Android device, though I receive the error about missing stdlib.h. I found out that this library is actually inside sub directory tr1 of includes. I modified the include<stdlib.h> to include<tr1/stdlib.h>. After this I encountered the error for locale.h. This files doesn't seem to be present anywhere in the NDK.
The app works fine if build for Desktop as the Linux GCC has all files in proper hierarchy.
Any fixes?
Finally, I resolved the issue. It was just the wrong Android NDK build I downloaded. My system architecture is x86_64 and the Android architecture is x86. The build I downloaded was that x86_64 Android. Make sure when downloading the target platform is your Android architecture.
Also, one might find several solutions recommending to create stand-alone build using make-standalone-toolchain.sh script and setting CXX home to this build and as well as set "sysroot". Please do not do it. It's not at all required. Just set the NDK path from Android option from Qt itself. That shall be enough.

gdb command 'info sharedlibrary' stucks on android

So I compiled a gdb from source using target=arm-elf-linux and a gdbserver using host=arm-linux-androideabi. Everything works fine with debugging native code on android except that if I type 'info sharedlibrary', it's stuck.
I tried different sets of versions of gdb+gdbserver, including the ones from the latest google NDK, they appears to have the same problem sticking on searching all libraries currently loaded in memory. So I assume this is not the fault of me choosing wrong versions of gdb but the android system on phone.
Is it right? What can I do to make it work?

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