How to run gdb with LD_PRELOAD?

gdb, qemu

Solution

`GDB` does not invoke your executable directly. Instead, it does

bash -c '/nfs_home/chenwj/tools/bin/qemu-i386  -U LD_PRELOAD bzip2_base.i386-m32-gcc44-annotated input.source 1'

This is done so that bash takes care of I/O redirection (which you are not using).

My guess is that `/bin/bash` doesn't work when LD_PRELOAD=libdbo.so is in effect, though I don't understand the exact nature of failure.

One way to work around this problem is to create a wrapper executable, implementing `C` equivalent of this:

export LD_PRELOAD=/nfs_home/chenwj/tools/lib/libdbo.so
exec /nfs_home/chenwj/tools/bin/qemu-i386 "$@"

and debug that executable (without setting `LD_PRELOAD`). You'll see an extra `SIGTRAP` when the wrapper `execve()`s the wrapped `qemu-i386`, which you should ignore and `continue`.

Problem

Original source