I'm trying to debug a 32-bit executable on a 64-bit Ubuntu system. It runs just fine by itself from the command line, but when I try to use gdb, it hangs in ld-linux.so.2. Also, gdb works for the 64-bit version of the executable. Does anyone have a clue as to what I should try?
I just re-imaged a machine to Ubuntu 18.04.3, and I installed the multilib versions of gcc and g++.
Thanks in advance.
gdb <executable>
GNU gdb ...
This GDB was configured as "x86_64-linux-gnu"
...
Reading symbols from <executable>...done.
(gdb) show archi
The target architecture is set automatically (currently i386)
(gdb) break main
Breakpoint 1 at ...
(gdb) run
Starting program...
warning: Breakpoint address adjusted from 0xf7fd9be0 to 0xfffffffff7fd9be0.
...
(7 of these)
[hangs...]
[In another terminal, ran 'kill -CONT <pid>']
Program received signal SIGCONT, Continued.
0xf7fd9be0 in ?? () from /lib/ld-linux.so.2
(gdb) cont
[hangs again...]
Probably this gdb bug: https://sourceware.org/bugzilla/show_bug.cgi?id=23210
Try upgrading to the current GDB version (8.3.1). If Ubuntu doesn't offer a package for that, you can try compiling it yourself.
@EmployedRussian suggested in his edit to the question:
By downgrading from gdb=8.1-0ubuntu3.1 to gdb=8.1-0ubuntu3 the debugger started working again for me.
This also worked for me on Ubuntu 18.04.3. You should issue these commands:
sudo apt install gdb=8.1-0ubuntu3 # downgrade GDB to the working version
sudo apt-mark hold gdb # prevent upgrading (until the repository version is fixed)
I created a bug report for Ubuntu: https://bugs.launchpad.net/ubuntu/+source/gdb/+bug/1848200
You can click Does this bug affect you? if you have an Ubuntu account to get it fixed sooner.
来源：https://stackoverflow.com/questions/58225562/how-to-fix-hang-in-gdb-in-ld-linux-so-2-when-running-a-32-bit-executable-on-a-64