gdbstub initial code, v4

[Oleg Nesterov]

Changes:

Only internal cleanups. I was busy with utrace fixes
and testing.

With utrace patches I sent, I do not see any problems so far.
But utrace definitely needs more changes.

Next step: handle exit correctly and report W/S. I misunderstood
what gdbserver does when the main thread exits, it is not stupid
as I wrongly thought.

Note the second attachment, GDBCAT. It is just the simple perl
script which connects /proc/ugdb to tcp port. It can be used for
remote debugging via tcp, or with (unpatched) gdb which can't do
select() on /proc/ugdb. Actually, it is more convenient to use
it in any case, at least for logging purposes.

Oleg.

[Roland McGrath]

Post by Oleg Nesterov
Note the second attachment, GDBCAT. It is just the simple perl
script which connects /proc/ugdb to tcp port. It can be used for
remote debugging via tcp, or with (unpatched) gdb which can't do
select() on /proc/ugdb.

bash$ nc -l 2000 <> /proc/ugdb &

Post by Oleg Nesterov
Actually, it is more convenient to use
it in any case, at least for logging purposes.

(gdb) set remote debug 1


Thanks,
Roland

[Oleg Nesterov]

Post by Roland McGrath

Post by Oleg Nesterov
Note the second attachment, GDBCAT. It is just the simple perl
script which connects /proc/ugdb to tcp port. It can be used for
remote debugging via tcp, or with (unpatched) gdb which can't do
select() on /proc/ugdb.

bash$ nc -l 2000 <> /proc/ugdb &

Yes, this works,

Post by Roland McGrath

Post by Oleg Nesterov
Actually, it is more convenient to use
it in any case, at least for logging purposes.

(gdb) set remote debug 1

set debug remote 1. Yes, I tried this. Very, very inconvenient.
In this case the debugging output is mixed with the normal output,

Also: you can't save to file, can't filter packets, can't add
the packet for debugging (not implemented yet).

But yes, it is not strictly necessary, nc should work too.

Oleg.

[Daniel Jacobowitz]

Post by Oleg Nesterov

Post by Roland McGrath
(gdb) set remote debug 1

set debug remote 1. Yes, I tried this. Very, very inconvenient.
In this case the debugging output is mixed with the normal output,
Also: you can't save to file, can't filter packets, can't add
the packet for debugging (not implemented yet).

set remotelogfile filename addresses those first two. I don't know
what you mean by the last thing, but if it's useful, gdb can perhaps grow a
way to do it.