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From: Roland McGrath <roland@redhat.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: archer@sourceware.org, utrace-devel@redhat.com
Subject: Re: gdbstub initial code, v16
Date: Tue, 16 Nov 2010 20:02:00 -0000	[thread overview]
Message-ID: <20101116200226.BDD7B40147@magilla.sf.frob.com> (raw)
In-Reply-To: Oleg Nesterov's message of  Monday, 15 November 2010 20:05:37 +0100 <20101115190537.GA15725@redhat.com>

> Well. I can't say this change is good. Because ugdb uses (unexported)
> arch_ptrace() to set debugregs in a very much x86-specific way. However,
> I do not see what else can I do.

That kludge is unworkable in several ways.  It is just not worth pursuing.
Just use hw_breakpoint on kernels that have it, and don't try to support
the feature on kernels that don't.

> Say, should I implement vRun? From the very beginnig, I hate the idea
> to exec the target from kernel space, but otoh I'm afraid this is
> important for gdb users.

We've also vaguely discussed doing some hybrid solution where gdb does
something different for "run".  If you can do a kludge to implement vRun
fairly quickly and it works OK--including that it remains possible for
ugdb to be a module--then go ahead.  If that is too ungainly, or is just
plain infeasible (which I think it might be), then don't bend over
backwards for it.  We may have reached the end of what it's possible to
get done at all sensibly without more active involvement from the GDB team.


Thanks,
Roland

  reply	other threads:[~2010-11-16 20:02 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-15 19:12 Oleg Nesterov
2010-11-16 20:02 ` Roland McGrath [this message]
     [not found] ` <20110215204148.GA17258@host1.dyn.jankratochvil.net>
     [not found]   ` <20110215215438.CBD0E1806E0@magilla.sf.frob.com>
     [not found]     ` <20110216214423.GA22228@redhat.com>
     [not found]       ` <20110216220541.55E701802A2@magilla.sf.frob.com>
     [not found]         ` <20110217211225.GA17768@redhat.com>
     [not found]           ` <20110221193927.122901814AE@magilla.sf.frob.com>
     [not found]             ` <20110222203834.GA6977@redhat.com>
2011-02-23 15:51               ` safe PTRACE_ATTACH Jan Kratochvil
2011-02-23 17:24                 ` Oleg Nesterov

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