How to get rid of libthread_db

Question

On an embedded file system, I would like to get rid of libthread_db. My understanding was that it was only necessary when debugging a program using pthread. However, here is my observation :

• If the libthread_db is not present at boot time (when the first pthread using programm is launched), launching such a program causes a segfault.

• Adding libthread_db later (ie after a pthread program has segfaulted) doesn't change anything. Every program that uses pthread will segfault on launch.

So it seems libthread_db is essential to run any sort of program using pthread.

Answer 1

you need to use target record

http://sources.redhat.com/ml/gdb/2010-07/msg00096.html

Answer 2

libthread_db is never used by a threaded program. It is only used by the debugger.

Your assertion that libthread_db is somehow required to run a program using pthreads is incorrect. If your pthread programs crash when libthread_db is removed from the system, something else is broken on your embedded target; removal of libthread_db merely triggers that something else.

You can trivially confirm this: build a pthread program on a regular Linux system. Run that program under strace, and observe that libthread_db does not appear in strace output. Now rename /lib/libthread_db.so.1 to something else, and observe that the test program continues to work just fine.