From mboxrd@z Thu Jan 1 00:00:00 1970 From: fche@redhat.com (Frank Ch. Eigler) Subject: Re: linux-next: add utrace tree Date: Tue, 26 Jan 2010 19:38:45 -0500 Message-ID: References: <20100121013822.28781960.sfr@canb.auug.org.au> <20100122005147.GD22003@redhat.com> <20100121170541.7425ff10.akpm@linux-foundation.org> <20100122182827.GA13185@redhat.com> <20100122200129.GG22003@redhat.com> <20100122221348.GA4263@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: (Tom Tromey's message of "Tue, 26 Jan 2010 16:20:22 -0700") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: utrace-devel-bounces@redhat.com Errors-To: utrace-devel-bounces@redhat.com To: Tom Tromey Cc: Stephen Rothwell , Kyle Moffett , Peter Zijlstra , Peter Zijlstra , Fr??d??ric Weisbecker , Oleg Nesterov , Steven Rostedt , LKML , Arnaldo Carvalho de Melo , linux-next@vger.kernel.org, "H. Peter Anvin" , utrace-devel@redhat.com, Thomas Gleixner , Linus Torvalds List-Id: linux-next.vger.kernel.org tromey wrote: > [...] > In non-stop mode (where you can stop one thread but leave the others > running), gdb wants to have the breakpoints always inserted. So, > something must emulate the displaced instruction. This sounds like the sort of thing that kernel kprobes do, which the uprobes patch does for userspace. The gdbstub prototype can use uprobes for such "displaced" breakpoints, and single-step-out-of-line to execute them on a few platforms like x86-*. This is already prototyped / working. (gdbstub currently restricts itself to single-threaded programs only, but that's another todo.) - FChE