Search code examples
boostgdbembedded-linuxglibcyocto

Segmentation fault only during GDB debugging


I cross-compiled the app, that uses boost::asio library, and tested it on my target system. It works properly. But when I try to debug my app with gdb, I get this message in gdb-console:

Program received signal SIGSEGV, Segmentation fault.
_dl_debug_initialize (ldbase=4294967292, ns=1996288212) at dl-debug.c:55
55           if (r->r_map == NULL || ldbase != 0)

The result is the same for remote and native debugging, and for several other boost libraries (but not for all). After searching any information, that could be helpful, I found similar problem in this doc (p.63): http://support.garz-fricke.com/products/Santaro/Linux-Yocto/Releases/Yocto-jethro-5.1-r6859-0/GUF-Yocto-jethro-5.1-r6859-0-IMX6GUF-Manual.pdf As said in the document the problem can be caused by "Static instanciation in implicitly implemented C++ methods" and is connected to glibc. So I tried to reproduce this bug by this approach with code:

#include <iostream> 
using namespace std; 
class AClass 
{ 
public:   
  void foo()   
  {
    static int NmbOfInvokes = 0;
    NmbOfInvokes++;
    cout << NmbOfInvokes << endl;   
  } 
};
int main(void) 
{
  cout << "Hello World" << endl;

  AClass anInstance;
  anInstance.foo();
  anInstance.foo();
  return 0;
}

This program works properly, but in debugging fails with the same SIGSEGV error.

To fix it enough to rewrite class AClass in this way:

class AClass
{
public:
  void foo();
};

void AClass::foo()
{
  static int NmbOfInvokes = 0;
  NmbOfInvokes++;
  cout << NmbOfInvokes << endl;
}

The compilation flags:

arm-poky-linux-gnueabi-g++  -march=armv7-a -mfloat-abi=hard -mfpu=neon -mtune=cortex-a7 --sysroot=/opt/fsl-imx-x11/4.1.15-1.2.0/sysroots/cortexa7hf-vfp-neon-poky-linux-gnueabi -DHAVE_CONFIG_H -I. -I..   --sysroot=/opt/fsl-imx-x11/4.1.15-1.2.0/sysroots/cortexa7hf-vfp-neon-poky-linux-gnueabi  -g -O0  --sysroot=/opt/fsl-imx-x11/4.1.15-1.2.0/sysroots/cortexa7hf-vfp-neon-poky-linux-gnueabi -MT SegFault_Reproduce.o -MD -MP -MF .deps/SegFault_Reproduce.Tpo -c -o SegFault_Reproduce.o SegFault_Reproduce.cpp mv -f .deps/SegFault_Reproduce.Tpo .deps/SegFault_Reproduce.Po
../arm-poky-linux-gnueabi-libtool  --tag=CXX   --mode=link arm-poky-linux-gnueabi-g++  -march=armv7-a -mfloat-abi=hard -mfpu=neon -mtune=cortex-a7 --sysroot=/opt/fsl-imx-x11/4.1.15-1.2.0/sysroots/cortexa7hf-vfp-neon-poky-linux-gnueabi  -g -O0  --sysroot=/opt/fsl-imx-x11/4.1.15-1.2.0/sysroots/cortexa7hf-vfp-neon-poky-linux-gnueabi  --sysroot=/opt/fsl-imx-x11/4.1.15-1.2.0/sysroots/cortexa7hf-vfp-neon-poky-linux-gnueabi -o SegFault_Reproduce SegFault_Reproduce.o  
arm-poky-linux-gnueabi-libtool: link: arm-poky-linux-gnueabi-g++ -march=armv7-a -mfloat-abi=hard -mfpu=neon -mtune=cortex-a7 --sysroot=/opt/fsl-imx-x11/4.1.15-1.2.0/sysroots/cortexa7hf-vfp-neon-poky-linux-gnueabi -g -O0 --sysroot=/opt/fsl-imx-x11/4.1.15-1.2.0/sysroots/cortexa7hf-vfp-neon-poky-linux-gnueabi --sysroot=/opt/fsl-imx-x11/4.1.15-1.2.0/sysroots/cortexa7hf-vfp-neon-poky-linux-gnueabi -o SegFault_Reproduce SegFault_Reproduce.o

I suppose that in some boost libraries are used similar static instanciation, because the symptoms are exactly the same.

What can I do to receive the possibility of debugging boost applications?

The versions of packages that I used: yocto 2.0.1, gcc 5.2.0, gdb 7.9.1, boost 1.58.


Solution

  • But when I try to debug my app with gdb, I get this message

    This suggests a bug in GDB. Your version: 7.9.1 is almost 2 years old. Your first step should be to try a more recent GDB release.

    One difference between "under GDB" and "native" execution is that GDB disables ASLR.

    You can try (gdb) set disable-randomization off before running the program. But given the symptoms you described, I doubt that has anything to do with the problem.