From patchwork Fri Oct 24 17:40:37 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pedro Alves X-Patchwork-Id: 3359 Received: (qmail 6664 invoked by alias); 24 Oct 2014 17:40:45 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 6645 invoked by uid 89); 24 Oct 2014 17:40:44 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.7 required=5.0 tests=AWL, BAYES_00, RP_MATCHES_RCVD, SPF_HELO_PASS, SPF_PASS autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Fri, 24 Oct 2014 17:40:43 +0000 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s9OHedZS005123 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 24 Oct 2014 13:40:40 -0400 Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s9OHebXp003073; Fri, 24 Oct 2014 13:40:38 -0400 Message-ID: <544A8F15.9000906@redhat.com> Date: Fri, 24 Oct 2014 18:40:37 +0100 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 MIME-Version: 1.0 To: Sandra Loosemore CC: gdb-patches@sourceware.org Subject: Re: Cannot execute this command without a live selected thread. References: <544A7648.6060102@codesourcery.com> <544A7930.4040909@redhat.com> <544A8741.9090705@codesourcery.com> <544A8B0C.5000509@redhat.com> In-Reply-To: <544A8B0C.5000509@redhat.com> On 10/24/2014 06:23 PM, Pedro Alves wrote: > On 10/24/2014 06:07 PM, Sandra Loosemore wrote: >> Sending packet: $?#3f...Packet received: S00 >> Sending packet: $qfThreadInfo#bb...Packet received: l > > Huh, I think this is the problem. > > So this target supports qfThreadInfo, but then it's returning > an empty thread list... remote_update_thread_list will delete > threads from GDB's list that are not found in the thread list that > the target reported. Why is the target reporting that empty list? > > See ab970af19746364a4f236bebc238ebb036adc898. > > We may be able add a workaround for this. :-/ Just in case, > can you confirm that the current thread's ptid (inferior_ptid) > is magic_null_ptid? Please give this a try. From 2062235a91a3c69e73c39b0f8a4f78f4ec396931 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Fri, 24 Oct 2014 18:27:14 +0100 Subject: [PATCH] gdb/ 2014-10-24 Pedro Alves * remote.c (remote_thread_alive): New, factored out from ... (remote_thread_alive): ... this. (remote_update_thread_list): Bail out before deleting threads if the target returned an empty list, and, the current thread has a magic/fake ptid. --- gdb/remote.c | 35 ++++++++++++++++++++++++++++++++--- 1 file changed, 32 insertions(+), 3 deletions(-) diff --git a/gdb/remote.c b/gdb/remote.c index 20f2988..affc7c2 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -1842,11 +1842,11 @@ set_general_process (void) } -/* Return nonzero if the thread PTID is still alive on the remote - system. */ +/* Return nonzero if this is the main thread that we made up ourselves + to model non-threaded targets as single-threaded. */ static int -remote_thread_alive (struct target_ops *ops, ptid_t ptid) +remote_thread_always_alive (struct target_ops *ops, ptid_t ptid) { struct remote_state *rs = get_remote_state (); char *p, *endp; @@ -1861,6 +1861,23 @@ remote_thread_alive (struct target_ops *ops, ptid_t ptid) multi-threading. */ return 1; + return 0; +} + +/* Return nonzero if the thread PTID is still alive on the remote + system. */ + +static int +remote_thread_alive (struct target_ops *ops, ptid_t ptid) +{ + struct remote_state *rs = get_remote_state (); + char *p, *endp; + + /* Check if this is a thread that we made up ourselves to model + non-threaded targets as single-threaded. */ + if (remote_thread_always_alive (ops, ptid)) + return 1; + p = rs->buf; endp = rs->buf + get_remote_packet_size (); @@ -2780,6 +2797,18 @@ remote_update_thread_list (struct target_ops *ops) got_list = 1; + if (VEC_empty (thread_item_t, context.items) + && remote_thread_always_alive (ops, inferior_ptid)) + { + /* Some targets don't really support threads, but still + reply an (empty) thread list in response to the thread + listing packets, instead of replying "packet not + supported". Exit early so we don't delete the main + thread. */ + do_cleanups (old_chain); + return; + } + /* CONTEXT now holds the current thread list on the remote target end. Delete GDB-side threads no longer found on the target. */