From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 81209 invoked by alias); 26 Nov 2019 17:07:53 -0000 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 Received: (qmail 81201 invoked by uid 89); 26 Nov 2019 17:07:53 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-9.0 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.3.1 spammy= X-HELO: mx1.osci.io Received: from polly.osci.io (HELO mx1.osci.io) (8.43.85.229) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 26 Nov 2019 17:07:52 +0000 Received: by mx1.osci.io (Postfix, from userid 994) id A341C20387; Tue, 26 Nov 2019 12:07:48 -0500 (EST) Received: from gnutoolchain-gerrit.osci.io (gnutoolchain-gerrit.osci.io [8.43.85.239]) by mx1.osci.io (Postfix) with ESMTP id 6F6BC201F1; Tue, 26 Nov 2019 12:07:47 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by gnutoolchain-gerrit.osci.io (Postfix) with ESMTP id 4533420AF6; Tue, 26 Nov 2019 12:07:47 -0500 (EST) X-Gerrit-PatchSet: 2 Date: Tue, 26 Nov 2019 17:07:00 -0000 From: "Mihails Strasuns (Code Review)" To: gdb-patches@sourceware.org Cc: Simon Marchi Auto-Submitted: auto-generated X-Gerrit-MessageType: comment Subject: [review v2] jit: remove bp locations when unregistering jit code X-Gerrit-Change-Id: Id9133540d67fa0c4619ac88324b0349b89e4b2b1 X-Gerrit-Change-Number: 704 X-Gerrit-ChangeURL: X-Gerrit-Commit: 232c479ef55b074173b1547b2072916bba6904c2 In-Reply-To: References: X-Gerrit-Comment-Date: Tue, 26 Nov 2019 12:07:46 -0500 Reply-To: gnutoolchain-gerrit@osci.io MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Disposition: inline User-Agent: Gerrit/3.0.3-79-g83ff7f88f1 Content-Type: text/plain; charset=UTF-8 Message-Id: <20191126170747.4533420AF6@gnutoolchain-gerrit.osci.io> X-SW-Source: 2019-11/txt/msg00872.txt.bz2 Mihails Strasuns has posted comments on this change. Change URL: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/704 ...................................................................... Patch Set 2: > So to unregister a jit region and register a new one (that would happen to have the exact same code at the exact same address as the previous one), the process would need to call __jit_debug_register_code twice, executing between the two events. Correct. > After unregistration, when the execution resumes, shouldn't there be something that deletes the breakpoint locations related to that objfile that was removed? And then when __jit_debug_register_code for registering the new object, we would re-create brand new breakpoint locations? To be honest I hoped someone here will be able to explain this to me :) But no, this is not how gdb works right now - removal of object files does not cause existing breakpoint locations to be removed, it only clears matching symtab reference (see `breakpoint_free_objfile`). Normally it doesn't cause any problems because next time the same object file appears again, a new breakpoint location gets created/inserted with the new address. The only possible explanation I could think of is that it is somehow possible for objfile instance to be deleted with the matching instruction memory still being accessible - and that such breakpoint location is still expected to hit. But some sort of historical quirk is always possible of course. -- Gerrit-Project: binutils-gdb Gerrit-Branch: master Gerrit-Change-Id: Id9133540d67fa0c4619ac88324b0349b89e4b2b1 Gerrit-Change-Number: 704 Gerrit-PatchSet: 2 Gerrit-Owner: Mihails Strasuns Gerrit-Reviewer: Mihails Strasuns Gerrit-CC: Simon Marchi Gerrit-Comment-Date: Tue, 26 Nov 2019 17:07:46 +0000 Gerrit-HasComments: No Gerrit-Has-Labels: No Gerrit-MessageType: comment