From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 128713 invoked by alias); 24 Nov 2015 16:34:45 -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 128694 invoked by uid 89); 24 Nov 2015 16:34:45 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.1 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_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; Tue, 24 Nov 2015 16:34:44 +0000 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (Postfix) with ESMTPS id 3E0DA2DC379; Tue, 24 Nov 2015 16:34:43 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id tAOGYfeV028709; Tue, 24 Nov 2015 11:34:42 -0500 Message-ID: <565491A1.8020408@redhat.com> Date: Tue, 24 Nov 2015 16:34:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Yao Qi CC: gdb-patches@sourceware.org Subject: Re: [PATCH 04/18] gdbserver crash running gdb.threads/non-ldr-exc-1.exp References: <1444836486-25679-1-git-send-email-palves@redhat.com> <1444836486-25679-5-git-send-email-palves@redhat.com> <86mvv52920.fsf@gmail.com> In-Reply-To: <86mvv52920.fsf@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-SW-Source: 2015-11/txt/msg00505.txt.bz2 On 10/26/2015 10:55 AM, Yao Qi wrote: > I do something similar in AArch64 GDBserver backend to fix the crash. > Could you include this patch in your series if it is OK to you? My > patch depends on your patch 04/18. > Note that I didn't add "set_general_process" as you suggested, because I > am not 100% sure the rules of switching current_thread. > Hmm, using one of the new Aarch64 machines on the GCC compile farm, I see that the crash comes from here: (gdb) bt #0 0x0000000000408074 in inferior_regcache_data (inferior=0x0) at ../../../src/gdb/gdbserver/inferiors.c:281 #1 0x000000000040840c in get_thread_regcache (thread=0x0, fetch=0) at ../../../src/gdb/gdbserver/regcache.c:31 #2 0x000000000042fb14 in is_64bit_tdesc () at ../../../src/gdb/gdbserver/linux-aarch64-low.c:84 #3 0x0000000000430098 in aarch64_supports_z_point_type (z_type=48 '0') at ../../../src/gdb/gdbserver/linux-aarch64-low.c:264 #4 0x00000000004422cc in linux_supports_z_point_type (z_type=48 '0') at ../../../src/gdb/gdbserver/linux-low.c:5629 #5 0x000000000041a0e8 in z_type_supported (z_type=48 '0') at ../../../src/gdb/gdbserver/mem-break.c:930 #6 0x000000000041a234 in check_gdb_bp_preconditions (z_type=48 '0', err=0x7fc1dcccb8) at ../../../src/gdb/gdbserver/mem-break.c:1021 #7 0x000000000041a380 in delete_gdb_breakpoint (z_type=48 '0', addr=4196520, kind=4) at ../../../src/gdb/gdbserver/mem-break.c:1093 #8 0x000000000041650c in process_serial_event () at ../../../src/gdb/gdbserver/server.c:4193 #9 0x000000000041690c in handle_serial_event (err=0, client_data=0x0) at ../../../src/gdb/gdbserver/server.c:4323 #10 0x000000000041e74c in handle_file_event (event_file_desc=4) at ../../../src/gdb/gdbserver/event-loop.c:428 #11 0x000000000041dbf8 in process_event () at ../../../src/gdb/gdbserver/event-loop.c:184 #12 0x000000000041eb64 in start_event_loop () at ../../../src/gdb/gdbserver/event-loop.c:547 #13 0x0000000000415204 in captured_main (argc=4, argv=0x7fc1dcd0e8) at ../../../src/gdb/gdbserver/server.c:3688 #14 0x0000000000415434 in main (argc=4, argv=0x7fc1dcd0e8) at ../../../src/gdb/gdbserver/server.c:3773 And that is_64bit_tdesc call was added by 6085d6f6: --- a/gdb/gdbserver/linux-aarch64-low.c +++ b/gdb/gdbserver/linux-aarch64-low.c @@ -364,6 +364,22 @@ aarch64_supports_z_point_type (char z_type) switch (z_type) { case Z_PACKET_SW_BP: + { + if (!extended_protocol && is_64bit_tdesc ()) + { + /* Only enable Z0 packet in non-multi-arch debugging. If + extended protocol is used, don't enable Z0 packet because + GDBserver may attach to 32-bit process. */ + return 1; + } + else + { + /* Disable Z0 packet so that GDBserver doesn't have to handle + different breakpoint instructions (aarch64, arm, thumb etc) + in multi-arch debugging. */ + return 0; + } + } Now that Antoine's series that teaches gdbserver about different breakpoint kinds is in, perhaps we could just revert 6085d6f6 now? Thanks, Pedro Alves