From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26733 invoked by alias); 21 Oct 2008 00:56:49 -0000 Received: (qmail 26714 invoked by uid 22791); 21 Oct 2008 00:56:48 -0000 X-Spam-Check-By: sourceware.org Received: from ti-out-0910.google.com (HELO ti-out-0910.google.com) (209.85.142.186) by sourceware.org (qpsmtpd/0.31) with ESMTP; Tue, 21 Oct 2008 00:56:10 +0000 Received: by ti-out-0910.google.com with SMTP id d10so1049665tib.12 for ; Mon, 20 Oct 2008 17:56:07 -0700 (PDT) Received: by 10.110.40.8 with SMTP id n8mr5414659tin.50.1224550567346; Mon, 20 Oct 2008 17:56:07 -0700 (PDT) Received: by 10.110.42.9 with HTTP; Mon, 20 Oct 2008 17:56:07 -0700 (PDT) Message-ID: Date: Tue, 21 Oct 2008 00:56:00 -0000 From: teawater To: "Pedro Alves" Subject: Re: [reverse/record] adjust_pc_after_break in reverse execution mode? Cc: "Michael Snyder" , "gdb-patches@sourceware.org" In-Reply-To: <200810210121.07914.pedro@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200810180210.16346.pedro@codesourcery.com> <48FCC413.3040506@vmware.com> <200810210121.07914.pedro@codesourcery.com> X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2008-10/txt/msg00500.txt.bz2 In replay mode, it can't change value of register. So I just can check if some address have breakpoint and stop execute in this address. On Tue, Oct 21, 2008 at 08:21, Pedro Alves wrote: > On Tuesday 21 October 2008 00:36:12, teawater wrote: >> I think your mean is check breakpoint in address >> read_pc()+gdbarch_decr_pc_after_break (gdbarch) in record_wait, right? > > Taking x86 as an example, when you're doing normal debugging and you > hit a breakpoint (SIGTRAP), the first read_pc GDB does to check where > what breakpoint was hit, will read back `breakpoint_PC + 1' --- GDB takes care > getting rid of that `+ 1' offset in infrun.c:adjust_pc_after_break. The > idea is for you to do the same as the kernel/hardware would --- still > check for breakpoints at read_pc, but increment PC by 1 before reporting the > breakpoint to GDB's core. E.g., see the `pc += gdbarch...' line from > the patch I posted previously, something like: > > record.c:record_wait () > { > ... > + /* Check for breakpoint hits in forward execution. */ > + pc = read_pc (); > + if (execution_direction == EXEC_FORWARD > + && regular_breakpoint_inserted_here_p (pc) > + /* && !single-stepping */) > + { > + status->kind = TARGET_WAITKIND_STOPPED; > + status->value.sig = TARGET_SIGNAL_TRAP; > + if (software_breakpoint_inserted_here_p (pc)) > + { > + pc += gdbarch_decr_pc_after_break (gdbarch); > + write_pc (pc); > + } > + > > -- > Pedro Alves >