On Sun, Apr 22, 2018 at 09:37:52PM -0400, Simon Marchi wrote:
On 2018-04-09 10:08 PM, Stefan Hajnoczi wrote:
I wonder what the point of select-frame is then...
I have CCed the GDB mailing list. Maybe someone can help us. Context:
QEMU implements coroutines using jmpbuf. We'd like to print coroutine
call stacks in GDB and have a script that works when a process is being
debugged (it sets the registers).
Now we'd like to extend the script to work on core dumps where it's not
possible to set registers (since there is no process being debugged).
Is there a way to backtrace an arbitrary call stack in a core dump?
Not that I know of. The "frame <stack-addr> <pc-addr>" form of the frame
command sounds like it should be usable to achieve that, but it doesn't
seem to work in that way. I really wonder if it's working as it was
intended initially. I guess using that form of the frame command should
override/mask the real current values of $sp and $pc?
Yes, that is what I was expecting.
Vladimir has a script to copy the coredump file and manipulate the
registers on disk, but it would be nicer to do stack-switching inside
the GDB session without needing to create another coredump file.
Vladimir: Would you like to write a GDB patch? If GDB is fixed then
workaround won't be necessary.