From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 06D893857025; Mon, 30 May 2022 16:18:50 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 06D893857025 From: "thiago.bauermann at linaro dot org" To: gdb-prs@sourceware.org Subject: [Bug testsuite/28561] [gdb/testsuite] Error due to not reading \r\n at end of mi prompt Date: Mon, 30 May 2022 16:18:49 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gdb X-Bugzilla-Component: testsuite X-Bugzilla-Version: 11.1 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: thiago.bauermann at linaro dot org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gdb-prs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-prs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 30 May 2022 16:18:50 -0000 https://sourceware.org/bugzilla/show_bug.cgi?id=3D28561 Thiago Jung Bauermann changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |thiago.bauermann at linaro= dot org --- Comment #7 from Thiago Jung Bauermann --- This bug isn't so easy to reproduce. I've been trying for the past few days on aarch64 machines, and I was able to observe it on these systems: 1. KVM guest running openSUSE Leap 15.3 2. Container with Ubuntu 20.04 userspace inside KVM guest with openSUSE Leap 15.3 3. Container with Ubuntu 22.04 userspace inside KVM guest with openSUSE Leap 15.3 I was not able to reproduce the problem on these systems: 4. KVM guest running Ubuntu 20.04 5. KVM guest running Ubuntu 22.04 6. KVM guest running Debian 10 (buster) 7. Bare metal Ubuntu 20.04 8. Container with Ubuntu 22.04 userspace on bare metal Ubuntu 20.04 9. Container with openSUSE Leap 15.3 userspace on bare metal Ubuntu 22.04 To me, this indicates that it's a kernel issue since there were three kernels tested and only one of them reproduced the problem. And of the three userspaces tested, they all reproduced the problem when used with the problematic kernel, and not when used with the other two kernels. Kernel I tested where the bug happens: - openSUSE Leap 15.3 5.3.18-150300.59.68-default Kernels I tested where the bug doesn't happen: - Ubuntu 20.04 5.4.0-110-generic - Ubuntu 22.04 5.15.0-30-generic - Debian 10 5.10.0-0.bpo.12-arm64 My hypothesis is that there was some kernel patch fixing the bug that was backported to the Ubuntu and Debian kernels but not to the openSUSE Leap kernel. I will try testing some upstream kernels to see if I can test the hypothesis and narrow down upstream kernel versions. The bug reproduces only after running the affected testcases for hundreds of iterations. It was easiest to hit with gdb.mi/user-selected-context-sync.ex= p. I also saw the problem happen with gdb.mi/mi-break.exp a couple of times. I did see gdb.gdb/unittest.exp (which is the test that fails in the GNU Toolchain buildbot) fail on an Ubuntu 22.04 KVM guest, so perhaps my =E2=80= =9Cit's the kernel=E2=80=9D theory is wrong. But this failure is an outlier in the = general pattern I'm seeing since it's much rarer to see this testcase fail (it fails once every several thousands of iterations rather than several hundreds), so I'll keep pursuing the kernel route before digging deeper into what's going on with gdb.gdb/unittest.exp. --=20 You are receiving this mail because: You are on the CC list for the bug.=