From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 124575 invoked by alias); 16 May 2016 22:06:17 -0000 Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org Received: (qmail 124555 invoked by uid 89); 16 May 2016 22:06:16 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.1 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.2 spammy=kyle, H*Ad:D*mozilla.org, replay, Hx-languages-length:1278 X-HELO: mail-oi0-f45.google.com Received: from mail-oi0-f45.google.com (HELO mail-oi0-f45.google.com) (209.85.218.45) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Mon, 16 May 2016 22:06:06 +0000 Received: by mail-oi0-f45.google.com with SMTP id k142so290724157oib.1 for ; Mon, 16 May 2016 15:06:06 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:date:message-id:subject:from:to:cc; bh=4N29194PXMEKIqhPCC38u7wu5pSDBI/zKdXQjTGD0ec=; b=Qhzw9gojXuTwQrC+B55bpWwP+zhmDuZEwKHfoTyA4SjvWF6K3uxnH8ZB//OMdKGJFO 3cgiC36KeZbIaE8ApzBcNTU4ltxBJHj6RclR07dd8bnBuNOn4tRo7a4OcYmjBVEVGqCw RP9eCZDENJHvzZnecTtkgn0AMdWEgMfrc7y0xUeL2uYQ+/tXKuZ/MbOJqAbfoTey7F9N miyWMBSVH0PDNOycOV+cXXSjF43ZL9VFEizT/hb7+yfpuCI7SjDljbYbset483LEfZ/I Ar42rMYioJYg6iBsPUlFUc1lmQKdvdDIIuTR+86KXXag4WZJXlUfjCkdZ7F3u8o689mi /KgA== X-Gm-Message-State: AOPr4FXcv2nEGnE4KE2nwzXCLfdwhZJT1znscBgkDgYatHvY/clWqojcM/j4m96cSuSZ7l9kqNR4b0fPbIIrkA== MIME-Version: 1.0 X-Received: by 10.157.14.15 with SMTP id c15mr3400997otc.77.1463436364891; Mon, 16 May 2016 15:06:04 -0700 (PDT) Received: by 10.202.89.213 with HTTP; Mon, 16 May 2016 15:06:04 -0700 (PDT) Date: Mon, 16 May 2016 22:06:00 -0000 Message-ID: Subject: [regression] gdb 7.11 breaks rr From: Kyle Huey To: gdb@sourceware.org Cc: rr-dev , Pedro Alves Content-Type: text/plain; charset=UTF-8 X-SW-Source: 2016-05/txt/msg00004.txt.bz2 (Resending because the gdb list rejects HTML mail, sorry for duplicates) Steps to reproduce: 1. Clone rr from https://github.com/mozilla/rr.git 2. Build rr rev 8566e3038892 3. ./bin/rr record ./bin/reverse_continue_process_signal 4. ./bin/rr replay -d /path/to/gdb-7.11 5. c 6. Once, the program has reached the SIGKILL, b 22 7. rc Instead of reversing to the fork on line 22, rr will stop again at the SIGKILL. Beginning with [0] gdb seems to forget which direction execution is heading in when a signal is reported by the gdb server. When gdb resumes execution after deciding to ignore the signal it sends a vCont instead of a bc to the gdb server, causing rr to execute forwards again. This was fixed after the release of gdb 7.11 by [1]. I verified that cherry-picking this commit on top of the gdb-7.11-release tag also fixes rr. Could we get this commit backported for a 7.11.1? rr's reverse execution features are largely unusable with complex programs (e.g. Firefox) because of this bug. Thanks, - Kyle [0] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=0b333c5e7d6c3fc65d37ffa11bd21ba52c4adb25 [1] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=3a00c80277a54abe0b286a6e8babc8fe50120205