From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4371 invoked by alias); 24 Mar 2019 14:25:18 -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 4110 invoked by uid 89); 24 Mar 2019 14:25:18 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-24.0 required=5.0 tests=AWL,BAYES_00,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,KAM_SHORT,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.1 spammy=prove, quit, stopped, resume X-HELO: mailsec106.isp.belgacom.be Received: from mailsec106.isp.belgacom.be (HELO mailsec106.isp.belgacom.be) (195.238.20.102) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Sun, 24 Mar 2019 14:25:14 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=skynet.be; i=@skynet.be; q=dns/txt; s=securemail; t=1553437514; x=1584973514; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=8+8AI2b17SFw56syltC7WsNHOEl6CJJintSXM2E0Rpc=; b=qhWuCPxB63i66jkddIo6seiT+S0F84VumY3XQFV7VrHvWLOZD6w+hUw0 HmWd7OXWtGSYV4Fqjb9q1HA+6wF9wA==; Received: from unknown (HELO md.home) ([109.130.122.147]) by relay.skynet.be with ESMTP/TLS/DHE-RSA-AES128-GCM-SHA256; 24 Mar 2019 15:25:12 +0100 From: Philippe Waroquiers To: gdb-patches@sourceware.org Cc: Philippe Waroquiers Subject: [RFA] Fix internal error with 'set debug infrun 1' under high load Date: Sun, 24 Mar 2019 14:25:00 -0000 Message-Id: <20190324142505.27486-1-philippe.waroquiers@skynet.be> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-IsSubscribed: yes X-SW-Source: 2019-03/txt/msg00516.txt.bz2 The test gdb.threads/watchthreads-reorder.exp verifies that the 'set debug infrun 1' debug output does not crash GDB. Under high load, the test can still cause a GDB internal error (see details below). This patch checks that ptid differs from null_ptid to call pid_to_str so that it does not crash. The change also outputs event_ptid. (top-gdb) bt #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51 #1 0x00007f3d54a0642a in __GI_abort () at abort.c:89 #2 0x0000555c24c60e66 in dump_core () at ../../fixleaks/gdb/utils.c:201 #3 0x0000555c24c63d49 in internal_vproblem(internal_problem *, const char *, int, const char *, typedef __va_list_tag __va_list_tag *) (problem=problem@entry=0x555c25338d40 , file=, line=287, fmt=, ap=) at ../../fixleaks/gdb/utils.c:411 #4 0x0000555c24c63eab in internal_verror (file=, line=, fmt=, ap=) at ../../fixleaks/gdb/utils.c:436 #5 0x0000555c249e8c22 in internal_error (file=file@entry=0x555c24e0f2ad "../../fixleaks/gdb/inferior.c", line=line@entry=287, fmt=) at ../../fixleaks/gdb/common/errors.c:55 #6 0x0000555c247d3f5c in find_inferior_pid (pid=) at ../../fixleaks/gdb/inferior.c:287 #7 0x0000555c24ad2248 in find_inferior_pid (pid=) at ../../fixleaks/gdb/inferior.c:302 #8 find_inferior_ptid (ptid=...) at ../../fixleaks/gdb/inferior.c:301 #9 0x0000555c24c35f25 in find_thread_ptid (ptid=...) at ../../fixleaks/gdb/thread.c:522 #10 0x0000555c24b0ab4d in thread_db_target::pid_to_str[abi:cxx11](ptid_t) ( this=0x555c2532e3e0 , ptid=...) at ../../fixleaks/gdb/linux-thread-db.c:1637 #11 0x0000555c24c2f420 in target_pid_to_str[abi:cxx11](ptid_t) (ptid=...) at ../../fixleaks/gdb/target.c:2083 #12 0x0000555c24ad9cab in stop_all_threads () at ../../fixleaks/gdb/infrun.c:4373 #13 0x0000555c24ada00f in stop_waiting (ecs=) at ../../fixleaks/gdb/infrun.c:7464 #14 0x0000555c24adc401 in process_event_stop_test (ecs=ecs@entry=0x7ffc9402d9d0) at ../../fixleaks/gdb/infrun.c:6181 ... (top-gdb) fr 12 #12 0x0000555c24ad9cab in stop_all_threads () at ../../fixleaks/gdb/infrun.c:4373 (top-gdb) p event_ptid $5 = {m_pid = 25419, m_lwp = 25427, m_tid = 0} (top-gdb) p ptid $6 = {m_pid = 0, m_lwp = 0, m_tid = 0} (top-gdb) p ws $7 = {kind = TARGET_WAITKIND_THREAD_EXITED, value = {integer = 0, sig = GDB_SIGNAL_0, related_pid = {m_pid = 0, m_lwp = 0, m_tid = 0}, execd_pathname = 0x0, syscall_number = 0}} (top-gdb) The gdb.log corresponding to the above crash is: (gdb) PASS: gdb.threads/watchthreads-reorder.exp: reorder1: set debug infrun 1 continue Continuing. infrun: clear_proceed_status_thread (Thread 0x7ffff7fcfb40 (LWP 25419)) infrun: clear_proceed_status_thread (Thread 0x7ffff7310700 (LWP 25427)) infrun: clear_proceed_status_thread (Thread 0x7ffff6b0f700 (LWP 25428)) infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT) infrun: proceed: resuming Thread 0x7ffff7fcfb40 (LWP 25419) infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [Thread 0x7ffff7fcfb40 (LWP 25419)] at 0x7ffff7344317 infrun: infrun_async(1) infrun: prepare_to_wait infrun: proceed: resuming Thread 0x7ffff7310700 (LWP 25427) infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [Thread 0x7ffff7310700 (LWP 25427)] at 0x5555555553d7 infrun: prepare_to_wait infrun: proceed: resuming Thread 0x7ffff6b0f700 (LWP 25428) infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [Thread 0x7ffff6b0f700 (LWP 25428)] at 0x5555555554c8 infrun: prepare_to_wait infrun: target_wait (-1.0.0, status) = infrun: -1.0.0 [process -1], infrun: status->kind = ignore infrun: TARGET_WAITKIND_IGNORE infrun: prepare_to_wait Joining the threads. [Thread 0x7ffff6b0f700 (LWP 25428) exited] infrun: target_wait (-1.0.0, status) = infrun: -1.0.0 [process -1], infrun: status->kind = ignore infrun: TARGET_WAITKIND_IGNORE infrun: prepare_to_wait infrun: target_wait (-1.0.0, status) = infrun: 25419.25419.0 [Thread 0x7ffff7fcfb40 (LWP 25419)], infrun: status->kind = stopped, signal = GDB_SIGNAL_TRAP infrun: TARGET_WAITKIND_STOPPED infrun: stop_pc = 0x555555555e50 infrun: context switch infrun: Switching context from Thread 0x7ffff6b0f700 (LWP 25428) to Thread 0x7ffff7fcfb40 (LWP 25419) infrun: BPSTAT_WHAT_STOP_NOISY infrun: stop_waiting infrun: stop_all_threads infrun: stop_all_threads, pass=0, iterations=0 infrun: Thread 0x7ffff7fcfb40 (LWP 25419) not executing infrun: Thread 0x7ffff7310700 (LWP 25427) executing, need stop [Thread 0x7ffff7310700 (LWP 25427) exited] infrun: target_wait (-1.0.0, status) = infrun: 25419.25427.0 [LWP 25427], infrun: status->kind = thread exited, status = 0 infrun: infrun_async(0) ../../fixleaks/gdb/inferior.c:287: internal-error: inferior* find_inferior_pid(int): Assertion `pid != 0' failed. A problem internal to GDB has been detected, further debugging may prove unreliable. Quit this debugging session? (y or n) FAIL: gdb.threads/watchthreads-reorder.exp: reorder1: continue to breakpoint: break-at-exit (GDB internal error) Resyncing due to internal error. n infrun: infrun_async(1) This is a bug, please report it. For instructions, see: . infrun: infrun_async(0) ../../fixleaks/gdb/inferior.c:287: internal-error: inferior* find_inferior_pid(int): Assertion `pid != 0' failed. A problem internal to GDB has been detected, further debugging may prove unreliable. Create a core file of GDB? (y or n) y --- gdb/infrun.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/gdb/infrun.c b/gdb/infrun.c index ad7892105a..111879c318 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -4368,9 +4368,13 @@ stop_all_threads (void) ptid_t ptid = ptid_t (ws.value.integer); fprintf_unfiltered (gdb_stdlog, - "infrun: %s exited while " + "infrun: %s " + "(event_ptid %s) exited while " "stopping threads\n", - target_pid_to_str (ptid).c_str ()); + ptid == null_ptid + ? "" + : target_pid_to_str (ptid).c_str (), + target_pid_to_str (event_ptid).c_str ()); } } else -- 2.20.1