segmentation fault
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Hello,
I make a qt application for Embedded Custom Board and when i run the Application it gives segmentation fault.
The application give segmentation fault due to following line.
mosq->subscribe(mosq->getMID(), topic.data(), 1);where mosq is define and declare as follow.
class MainWindow : public QMainWindow { Q_OBJECT public: explicit MainWindow(QWidget *parent = 0); ~MainWindow(); private: qtmosq* mosq = NULL; QStringList subed; QString currentTopic; Ui::MainWindow *ui; -------- -------- -------- };where qtmosq is define as follow..
#include "QObject" #include "mosquittopp.h" using namespace mosqpp; class qtmosq : public QObject, public mosquittopp { Q_OBJECT public: qtmosq(const char *id = NULL, bool clean_session = true) : mosquittopp (id, clean_session) {MID = 0;} ~qtmosq() {} void on_connect(int result) { if (!result) { //subscribe(NULL, "$SYS/#", 2); emit connected(); } else emit connectEnable(); } void on_publish(int id) { MID++; emit messageSent(true); } void on_subscribe(int mid, int qos_count, const int *granted_qos) { if (MID != 0) emit subscribed(); MID++; } .......... .......... .......... signals: void connected(); void messageSent(bool); void messageReceived(QString); void connectEnable(); void subscribed(); };so what is the reason behind for this fault.
The same application are successfully run on Host Linux PC.
I have use same mosquitto library in both the test.
please help me to sort out this problem.
I have send the reference link at where i used above program.
Link :- Ref. Link
Thank you
Milav Soniwrote on 15 Oct 2019, 16:51 last edited by@Milav said in segmentation fault:
Link :- Ref. Link
Could it be possible that you run such example AS IS, I mean just download/clone the code and try such example without any change.
If you manage to make it work, then you'll have the foundation to start adapting it to whatever you need/desire.In addition, is there any compelling reason not to use the Qt MQTT module?
Have you try any of the Qt MQTT examples? -
@Milav said in segmentation fault:
Link :- Ref. Link
Could it be possible that you run such example AS IS, I mean just download/clone the code and try such example without any change.
If you manage to make it work, then you'll have the foundation to start adapting it to whatever you need/desire.In addition, is there any compelling reason not to use the Qt MQTT module?
Have you try any of the Qt MQTT examples?wrote on 16 Oct 2019, 04:59 last edited by@Pablo-J-Rogina said in segmentation fault:
In addition, is there any compelling reason not to use the Qt MQTT module?
Have you try any of the Qt MQTT examples?I use actually qt4.8.7 source for development so QMqtt is not build for this qt version, so that i do not use qmqtt class.
if you have any idea how to run QMqtt in qt 4.8.7 source than please tell me it is so helpful to me.
@Pablo-J-Rogina said in segmentation fault:
Could it be possible that you run such example AS IS, I mean just download/clone the code and try such example without any change.
If you manage to make it work, then you'll have the foundation to start adapting it to whatever you need/desire.i actually tried same as is code for pc development and that is work fine.
but when i cross compiling the code for embedded target board than it gives segmentation error,
the difference between host pc and Embedded target board is only QT source.
Host pc => qmake (qt version 5.4.0 )
Embedded target => qmake (qt version 4.8.7)hope you got my point.
if you have any query please tell me.
and please guys help me to sort out the problem.
i am also try another code for the same , but in that i have also suffer same problem.
Another code link :- link text
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@Pablo-J-Rogina said in segmentation fault:
In addition, is there any compelling reason not to use the Qt MQTT module?
Have you try any of the Qt MQTT examples?I use actually qt4.8.7 source for development so QMqtt is not build for this qt version, so that i do not use qmqtt class.
if you have any idea how to run QMqtt in qt 4.8.7 source than please tell me it is so helpful to me.
@Pablo-J-Rogina said in segmentation fault:
Could it be possible that you run such example AS IS, I mean just download/clone the code and try such example without any change.
If you manage to make it work, then you'll have the foundation to start adapting it to whatever you need/desire.i actually tried same as is code for pc development and that is work fine.
but when i cross compiling the code for embedded target board than it gives segmentation error,
the difference between host pc and Embedded target board is only QT source.
Host pc => qmake (qt version 5.4.0 )
Embedded target => qmake (qt version 4.8.7)hope you got my point.
if you have any query please tell me.
and please guys help me to sort out the problem.
i am also try another code for the same , but in that i have also suffer same problem.
Another code link :- link text
@Milav OK, maybe we should start from the beginning.
Do you cross compile from PC to device?
Does the app crash in same way on host with Qt5?
Is it possible that you're mixing Qt4 and Qt5 on your target device? You can check this using "ldd EXECUTABLE" on your target.
Please do this on your target (in a terminal):file /opt/milav/qt-mosquitto ldd /opt/milav/qt-mosquittoand post the output here.
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@Milav OK, maybe we should start from the beginning.
Do you cross compile from PC to device?
Does the app crash in same way on host with Qt5?
Is it possible that you're mixing Qt4 and Qt5 on your target device? You can check this using "ldd EXECUTABLE" on your target.
Please do this on your target (in a terminal):file /opt/milav/qt-mosquitto ldd /opt/milav/qt-mosquittoand post the output here.
wrote on 16 Oct 2019, 05:39 last edited by@jsulm said in segmentation fault:
OK, maybe we should start from the beginning.
Okay sure.
@jsulm said in segmentation fault:
Do you cross compile from PC to device?
Yes i cross compile the "qt-mosquitto" application for target (device) from qt creator (that is install on pc).
For cross compilng i have use qmake version 4.8.7.
and qt creator version is "Qt Creator 3.3.0 (opensource)"
and for v
@jsulm said in segmentation fault:
Does the app crash in same way on host with Qt5?
No, the application is not crash in PC.
In pc i have use same code but qmake vwersion is 5.4.0
@jsulm said in segmentation fault:
Is it possible that you're mixing Qt4 and Qt5 on your target device? You can check this using "ldd EXECUTABLE" on your target.
In target i have only qt 4 library and qmake are there.
i think there is no qt 5 component in target device.@jsulm said in segmentation fault:
Please do this on your target (in a terminal):
sorry for this, but i have not ldd command on target device.
if it is necessary than tell i have install and cross compile it for target device.sorry i dont know why this ldd cmd is not there in target device.
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@jsulm said in segmentation fault:
OK, maybe we should start from the beginning.
Okay sure.
@jsulm said in segmentation fault:
Do you cross compile from PC to device?
Yes i cross compile the "qt-mosquitto" application for target (device) from qt creator (that is install on pc).
For cross compilng i have use qmake version 4.8.7.
and qt creator version is "Qt Creator 3.3.0 (opensource)"
and for v
@jsulm said in segmentation fault:
Does the app crash in same way on host with Qt5?
No, the application is not crash in PC.
In pc i have use same code but qmake vwersion is 5.4.0
@jsulm said in segmentation fault:
Is it possible that you're mixing Qt4 and Qt5 on your target device? You can check this using "ldd EXECUTABLE" on your target.
In target i have only qt 4 library and qmake are there.
i think there is no qt 5 component in target device.@jsulm said in segmentation fault:
Please do this on your target (in a terminal):
sorry for this, but i have not ldd command on target device.
if it is necessary than tell i have install and cross compile it for target device.sorry i dont know why this ldd cmd is not there in target device.
@Milav said in segmentation fault:
sorry i dont know why this ldd cmd is not there in target device
This is not unusual. On limited devices manufacturers usually remove everything not needed when using the device.
Is "file" command there? -
@Milav said in segmentation fault:
sorry i dont know why this ldd cmd is not there in target device
This is not unusual. On limited devices manufacturers usually remove everything not needed when using the device.
Is "file" command there?wrote on 16 Oct 2019, 05:46 last edited by@jsulm said in segmentation fault:
This is not unusual. On limited devices manufacturers usually remove everything not needed when using the device.
Is "file" command there?Okay no problem.
actually "file" cmd also not in target device.
but in desktop pc i have "file" cmd so i execute file cmd with binary application file.
here i have show output of that .
tdp0009@tdp0009-desktop:~$ file qt-mosquitto qt-mosquitto: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-, for GNU/Linux 2.6.32, not strippedi think you got your answer from above result.
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@jsulm said in segmentation fault:
This is not unusual. On limited devices manufacturers usually remove everything not needed when using the device.
Is "file" command there?Okay no problem.
actually "file" cmd also not in target device.
but in desktop pc i have "file" cmd so i execute file cmd with binary application file.
here i have show output of that .
tdp0009@tdp0009-desktop:~$ file qt-mosquitto qt-mosquitto: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-, for GNU/Linux 2.6.32, not strippedi think you got your answer from above result.
@Milav said in segmentation fault:
32-bit LSB executable, ARM, EABI5
Looks good if that's what your target device CPU is
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@Milav said in segmentation fault:
32-bit LSB executable, ARM, EABI5
Looks good if that's what your target device CPU is
wrote on 16 Oct 2019, 05:52 last edited by@jsulm said in segmentation fault:
Looks good if that's what your target device CPU is
yes. it is ARM based 32-bit CPU.
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@Milav OK, maybe we should start from the beginning.
Do you cross compile from PC to device?
Does the app crash in same way on host with Qt5?
Is it possible that you're mixing Qt4 and Qt5 on your target device? You can check this using "ldd EXECUTABLE" on your target.
Please do this on your target (in a terminal):file /opt/milav/qt-mosquitto ldd /opt/milav/qt-mosquittoand post the output here.
wrote on 16 Oct 2019, 06:08 last edited by@jsulm said in segmentation fault:
ldd /opt/milav/qt-mosquitto
hello ,
i explore and find some of the cmd for ldd.
here i have show the output for ldd qt-mosquitto/
Shared library: [libmosquittopp.so.1] 0x00000001 (NEEDED) Shared library: [libmosquitto.so.1] 0x00000001 (NEEDED) Shared library: [libdl.so.2] 0x00000001 (NEEDED) Shared library: [librt.so.1] 0x00000001 (NEEDED) Shared library: [libpthread.so.0] 0x00000001 (NEEDED) Shared library: [libstdc++.so.6] 0x00000001 (NEEDED) Shared library: [libm.so.6] 0x00000001 (NEEDED) Shared library: [libgcc_s.so.1] 0x00000001 (NEEDED) Shared library: [libc.so.6] 0x00000001 (NEEDED) Shared library: [ld-linux-armhf.so.3]hope now you got your answer.
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@Milav said in segmentation fault:
32-bit LSB executable, ARM, EABI5
Looks good if that's what your target device CPU is
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@Milav Did you try to cross compile a simple application and run it on your device?
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@Milav Then I suggest to start with a minimal application and add mqtt functionality in small pieces to see when it starts to crash.
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@Pablo-J-Rogina said in segmentation fault:
In addition, is there any compelling reason not to use the Qt MQTT module?
Have you try any of the Qt MQTT examples?I use actually qt4.8.7 source for development so QMqtt is not build for this qt version, so that i do not use qmqtt class.
if you have any idea how to run QMqtt in qt 4.8.7 source than please tell me it is so helpful to me.
@Pablo-J-Rogina said in segmentation fault:
Could it be possible that you run such example AS IS, I mean just download/clone the code and try such example without any change.
If you manage to make it work, then you'll have the foundation to start adapting it to whatever you need/desire.i actually tried same as is code for pc development and that is work fine.
but when i cross compiling the code for embedded target board than it gives segmentation error,
the difference between host pc and Embedded target board is only QT source.
Host pc => qmake (qt version 5.4.0 )
Embedded target => qmake (qt version 4.8.7)hope you got my point.
if you have any query please tell me.
and please guys help me to sort out the problem.
i am also try another code for the same , but in that i have also suffer same problem.
Another code link :- link text
wrote on 16 Oct 2019, 12:35 last edited by@Milav said in segmentation fault:
the difference between host pc and Embedded target board is only QT source.
Host pc => qmake (qt version 5.4.0 )
Embedded target => qmake (qt version 4.8.7)You should have stated these settings from the very beginning... :-)
Anyway, could it be possible that you build Qt 4.8.7 for PC (host) and build your example again with that Qt version and run in PC to see what happens.
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