From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 43355 invoked by alias); 14 Sep 2015 14:59:25 -0000 Mailing-List: contact gdb-testers-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-testers-owner@sourceware.org Received: (qmail 43340 invoked by uid 89); 14 Sep 2015 14:59:24 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=0.8 required=5.0 tests=AWL,BAYES_05,KAM_LAZY_DOMAIN_SECURITY autolearn=no version=3.3.2 X-HELO: kwanyin.sergiodj.net Received: from kwanyin.sergiodj.net (HELO kwanyin.sergiodj.net) (176.31.208.32) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-SHA encrypted) ESMTPS; Mon, 14 Sep 2015 14:59:23 +0000 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [binutils-gdb] Bail out of processing stop if hook-stop resumes target / changes context From: sergiodj+buildbot@redhat.com To: gdb-testers@sourceware.org Message-Id: <4c2f2a792a5971fcc7fe6511725eaf50d19d302b@gdb-build> Date: Mon, 14 Sep 2015 15:40:00 -0000 X-SW-Source: 2015-q3/txt/msg11387.txt.bz2 *** TEST RESULTS FOR COMMIT 4c2f2a792a5971fcc7fe6511725eaf50d19d302b *** Author: Pedro Alves Branch: master Commit: 4c2f2a792a5971fcc7fe6511725eaf50d19d302b Bail out of processing stop if hook-stop resumes target / changes context This patch, relative to a tree with https://sourceware.org/ml/gdb-patches/2015-08/msg00295.html, fixes issues/crashes that trigger if something unexpected happens during a hook-stop. E.g., if the inferior disappears while running the hook-stop, we hit failed assertions: (gdb) define hook-stop Type commands for definition of "hook-stop". End with a line saying just "end". >kill >end (gdb) si Kill the program being debugged? (y or n) [answered Y; input not from terminal] /home/pedro/gdb/mygit/build/../src/gdb/thread.c:88: internal-error: inferior_thread: Assertion `tp' failed. A problem internal to GDB has been detected, further debugging may prove unreliable. Quit this debugging session? (y or n) I noticed that if a hook-stop issues a synchronous execution command, we print the same stop event twice: (gdb) define hook-stop Type commands for definition of "hook-stop". End with a line saying just "end". >si >end (gdb) si 0x000000000040074a 42 args[i] = 1; /* Init value. */ <<<<<<< once 0x000000000040074a 42 args[i] = 1; /* Init value. */ <<<<<<< twice (gdb) In MI: *stopped,reason="end-stepping-range",frame={addr="0x000000000040074a",func="main",args=[],file="threads.c",fullname="/home/pedro/gdb/tests/threads.c",line="42"},thread-id="1",stopped-threads="all",core="0" *stopped,reason="end-stepping-range",frame={addr="0x000000000040074a",func="main",args=[],file="threads.c",fullname="/home/pedro/gdb/tests/threads.c",line="42"},thread-id="1",stopped-threads="all",core="0" (gdb) The fix has GDB stop processing the event if the context changed. I don't expect people to be doing crazy things from the hook-stop. E.g., it gives me headaches to try to come up a proper behavior for handling a thread change from a hook-stop... (E.g., imagine the hook-stop does thread N; step, with scheduler-locing on). I think the most important bit here is preventing crashes. The patch adds a new hook-stop.exp test that covers the above and also merges in the old hook-stop-continue.exp and hook-stop-frame.exp into the same framework. gdb/ChangeLog: 2015-09-14 Pedro Alves * infrun.c (current_stop_id): New global. (get_stop_id, new_stop_id): New functions. (fetch_inferior_event): Handle normal_stop proceeding the target. (struct stop_context): New. (save_stop_context, release_stop_context_cleanup) (stop_context_changed): New functions. (normal_stop): Return true if the hook-stop changes the stop context. * infrun.h (get_stop_id): Declare. (normal_stop): Now returns int. Add documentation. gdb/testsuite/ChangeLog: 2015-09-14 Pedro Alves * gdb.base/hook-stop-continue.c: Delete. * gdb.base/hook-stop-continue.exp: Delete. * gdb.base/hook-stop-frame.c: Delete. * gdb.base/hook-stop-frame.exp: Delete. * gdb.base/hook-stop.c: New file. * gdb.base/hook-stop.exp: New file.