Error: Program received signal SIGSEGV, Segmentation fault

[sheperson]

Hi,
I have compiled ns-2 on Ubuntu 9.10. Now when I try to run a simulation, I get segmentation fault error.
I tried gdb with ns (without debug enabled), and got this:


Program received signal SIGSEGV, Segmentation fault.
_IO_fread (buf=0xbfffd582, size=10, count=1, fp=0x0) at iofread.c:43
43 iofread.c: No such file or directory.
in iofread.c
I tried to enable debugging options in ns-2, using
./configure --enable-debug
but I get many errors, so I have to compile ns-2 without debug enabled.

Does anyone have any idea what is going on?

Thanks.

[dwhitney67]

The file pointer being passed to an fread() or similar function is null.

How to fix this? Who knows? I don't know what part of the code is causing it, but for such a simple error, I would suspect that...

1. You are using/running the application incorrectly;
2. The original coders of the application are somewhat incompetent (ie they didn't write defensive code to protect against null-pointers);
3. You built the application incorrectly.

As for item 3, is this application not available in the ubuntu application repository?

[sheperson]

The file pointer being passed to an fread() or similar function is null.

How to fix this? Who knows? I don't know what part of the code is causing it, but for such a simple error, I would suspect that...

1. You are using/running the application incorrectly;
2. The original coders of the application are somewhat incompetent (ie they didn't write defensive code to protect against null-pointers);
3. You built the application incorrectly.

As for item 3, is this application not available in the ubuntu application repository?

Hi,
Thanks for the tip. You are right, there was a null pointer passed to fread().
I found the piece of code causing the error, using gdb and backtrace.

Thanks again for your help.