Re: ping: Re: PATCH : allow to set length of hw watchpoints (e.g. for Valgrind gdbserver)

Philippe Waroquiers
2011-05-30T05:34:20Z

> One new command "set remote hardware-watchpoint-length-limit"
> is added in the patch, which is only useful to gdbserver+valgrind.
> When gdb is talking with normal gdbserver, it may be wrong to set
> hardware-watchpoint-length-limit in gdb side. Users should be careful
> when using this command.
I think the command is also useful in other cases
(cfr my other post of yesterday http://sourceware.org/ml/gdb-patches/2011-05/msg00664.html).

But if you believe this should be aimed only (or mainly) at Valgrind gdbserver,
I can update the patch (e.g. the documentation + change length default value)
to make it more Valgrind gdbserver specific.

> The ideal solution, IMO, is remote side gives GDB the value of
> hardware-watchpoint-length-limit, however, I don't know it is easy or
> hard to do such thing.

An approach where the remote side would tell which hw watchpoints are ok is the best.
It was discussed in another thread, but that is not easy to do.
E.g. for the moment, which hw watchpoints are accepted depends
on the order in which gdb inserts the watchpoints.

Currently, depending of the order of watchpoint insertion, you will even
trigger a bug in x86/amd64 gdbserver (cfr http://sourceware.org/ml/gdb-patches/2011-05/msg00664.html).

Philippe