From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by sourceware.org (Postfix) with ESMTPS id AE598385C40B for ; Thu, 25 Nov 2021 14:17:19 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org AE598385C40B Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id C3D53212BB; Thu, 25 Nov 2021 14:17:18 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id AA57D13B70; Thu, 25 Nov 2021 14:17:18 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id KxtnKO6an2EZCQAAMHmgww (envelope-from ); Thu, 25 Nov 2021 14:17:18 +0000 Subject: Re: [PATCHv2 5/6] gdb: add assert in remote_target::wait relating to async being off To: Andrew Burgess Cc: Simon Marchi , gdb-patches@sourceware.org References: <87c0ccf934cb31c7c636dcf0198bf128f38f821f.1637756330.git.aburgess@redhat.com> <59090c91-2342-d338-ba2f-17d441e5c452@simark.ca> <20211125100458.GP2662946@redhat.com> <98256892-d0a7-1332-cefe-2704e702179b@suse.de> <20211125134627.GT2662946@redhat.com> From: Tom de Vries Message-ID: <52c4ded1-02f7-8c7f-d830-809fcd2559d0@suse.de> Date: Thu, 25 Nov 2021 15:17:18 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <20211125134627.GT2662946@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-14.7 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, NICE_REPLY_A, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 25 Nov 2021 14:17:21 -0000 On 11/25/21 2:46 PM, Andrew Burgess wrote: > * Tom de Vries [2021-11-25 12:36:07 +0100]: > >> On 11/25/21 11:04 AM, Andrew Burgess via Gdb-patches wrote: >>> * Simon Marchi [2021-11-24 16:23:30 -0500]: >>> >>>> On 2021-11-24 7:22 a.m., Andrew Burgess via Gdb-patches wrote: >>>>> While working on another patch I ended up in a situation where I had >>>>> async mode disabled (with 'maint set target-async off'), but the async >>>>> event token got marked anyway. >>>>> >>>>> In this situation GDB was continually calling into >>>>> remote_target::wait, however, the async token would never become >>>>> unmarked as the unmarking is guarded by target_is_async_p. >>>>> >>>>> We could just unconditionally unmark the token, but that would feel >>>>> like just ignoring a bug, so, instead, lets assert that if >>>>> !target_is_async_p, then the async token should not be marked. >>>>> >>>>> This assertion would have caught my earlier mistake. >>>>> >>>>> There should be no user visible changes with this commit. >>>>> --- >>>>> gdb/remote.c | 6 +++++- >>>>> 1 file changed, 5 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/gdb/remote.c b/gdb/remote.c >>>>> index 25a4d3cab6e..da8ed81ba78 100644 >>>>> --- a/gdb/remote.c >>>>> +++ b/gdb/remote.c >>>>> @@ -8309,9 +8309,13 @@ remote_target::wait (ptid_t ptid, struct target_waitstatus *status, >>>>> remote_state *rs = get_remote_state (); >>>>> >>>>> /* Start by clearing the flag that asks for our wait method to be called, >>>>> - we'll mark it again at the end if needed. */ >>>>> + we'll mark it again at the end if needed. If the target is not in >>>>> + async mode then the async token should not be marked. */ >>>>> if (target_is_async_p ()) >>>>> clear_async_event_handler (rs->remote_async_inferior_event_token); >>>>> + else >>>>> + gdb_assert (!async_event_handler_marked >>>>> + (rs->remote_async_inferior_event_token)); >>>>> >>>>> ptid_t event_ptid; >>>>> >>>>> -- >>>>> 2.25.4 >>>>> >>>> >>>> LGTM. >>>> >>>> I think the series can be merged at least up to here, I think these are >>>> good cleanups. >>> >>> Thanks, I made the change you suggested about one target_can_async_p >>> function calling the other, and pushed patches 1 to 5. >>> >> >> I'm running into the assert: >> https://sourceware.org/bugzilla/show_bug.cgi?id=28627 . > > Sorry about that. I've reverted this patch, and closed the bug. > Np :) Thanks for the quick fix. - Tom > The cause of the assert is fixed by patch #6 in this series, so I > guess I'll remerge this patch after patch #6 lands. > > Thanks, > Andrew >