I' ve a cross-gdb configured with --host=i686-pc-linux-gnu --target=powerpc-e300c3-linux-gnu. i can correctly debug an application on a remote board with gdbserver but i get an error about a version mismatch between libthread_db and libpthread so i can't debug threads correctly (gdb recognizes only one thread instead of three threads). Maybe it's is due to a different version of libc: on host machine i've libc2.15 and on target machine lib2.5. I tried to rebuid libc2.5 for host in order to link gdb against to it but it's an hell. Before i get crazy to rebuild it, could someone confirm that it's a libc problem?
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1 Answer
I tried to rebuid libc2.5 for host in order to link gdb against to it
That's not what you need.
What you need, is for gdb to find and load libthread_db.so.1, that matches your target libpthread.so.0.
For this, you need to
- build
libc-2.5for host, and - set GDB's
libthread-db-search-pathsuch that it finds thelibthread_db.so.1built in step 1.
You don't actually need to build the entire libc in step 1. Something like this should suffice:
mkdir build && cd build
../configure --prefix=/usr
make -C ../nptl_db objdir=`pwd`
Update:
i have GDB 6.6 and there isn't libthread-db-search-path. What is another way to specify that path?
That GDB will just dlopen("libthread_db.so.1", ...). So to make it find the right libthread_db.so.1, you need to adjust LD_LIBRARY_PATH. Using bash:
LD_LIBRARY_PATH=/tmp/glibc-2.5/build/nptl_db gdb /path/to/target/a.out
6 Comments
MirkoBanchi
Thank you. I'll try to do that. However i have GDB 6.6 and there isn't libthread-db-search-path. What is another way to specify that path?
MirkoBanchi
libc by default doesn't allow to launch configure inside src root dir so i have a dir build and launch inside it ../configure --prefix=/usr but make -C ../nptl_db doesn't work due to path of config.make...any idea?
Employed Russian
@MirkoBanchi I've updated the answer for both of your comments.
MirkoBanchi
Thanks. However for now i can't rebuild ntpl_db
Employed Russian
@MirkoBanchi None of the versions of GDB I've seen do that. You can see what GDB is doing by also setting
LD_DEBUG=libs before invoking it. |
