<div dir="ltr"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> On 7/28/21, 11:14 AM, "<a href="mailto:crash-utility-bounces@redhat.com" target="_blank">crash-utility-bounces@redhat.com</a> on behalf of David Wysochanski" <<a href="mailto:crash-utility-bounces@redhat.com" target="_blank">crash-utility-bounces@redhat.com</a> on behalf of <a href="mailto:dwysocha@redhat.com" target="_blank">dwysocha@redhat.com</a>> wrote:<br> <br> On Wed, Apr 28, 2021 at 8:54 AM lijiang <<a href="mailto:lijiang@redhat.com" target="_blank">lijiang@redhat.com</a>> wrote:<br> ><br> > ? 2021?04?26? 19:17, <a href="mailto:crash-utility-request@redhat.com" target="_blank">crash-utility-request@redhat.com</a> ??:<br> > > Message: 3<br> > > Date: Mon, 26 Apr 2021 11:27:40 +0300<br> > > From: Vasily Averin <<a href="mailto:vvs@virtuozzo.com" target="_blank">vvs@virtuozzo.com</a>><br> > > To: <a href="mailto:crash-utility@redhat.com" target="_blank">crash-utility@redhat.com</a><br> > > Subject: [Crash-utility] crash does not work with last fedora kernels?<br> > > Message-ID: <<a href="mailto:8f8782a9-3da6-5d3c-c509-8b8ec8a30957@virtuozzo.com" target="_blank">8f8782a9-3da6-5d3c-c509-8b8ec8a30957@virtuozzo.com</a>><br> > > Content-Type: text/plain; charset=utf-8<br> > ><br> > > It looks like Fedora kernels uses gcc11 and generates debuginfo in DWARF 5 format.<br> > ><br> > > [root@localhost ~]# rpm -q crash<br> > > crash-7.2.9-5.fc35.x86_64<br> > > [root@localhost ~]# uname -a<br> > > Linux localhost.localdomain 5.11.12-300.fc34.x86_64 #1 SMP Wed Apr 7 16:31:13 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux<br> > ><br> > ><br> > > [root@localhost ~]# crash -1<br> > > Dwarf Error: wrong version in compilation unit header (is 5, should be 2, 3, or 4) [in module /usr/lib/debug/usr/lib/modules/5.11.12-300.fc34.x86_64/vmlinux]<br> > > crash: gdb_session_init: pulling in debug data by accessing init_mm.mmap<br> > > Dwarf Error: wrong version in compilation unit header (is 5, should be 2, 3, or 4) [in module /usr/lib/debug/usr/lib/modules/5.11.12-300.fc34.x86_64/vmlinux]<br> > ><br> > > crash: /usr/lib/debug/lib/modules/5.11.12-300.fc34.x86_64/vmlinux: no debugging data available<br> > ><br> > > [root@localhost ~]# ls -al /usr/lib/debug/lib/modules/5.11.12-300.fc34.x86_64/vmlinux<br> > > -rwxr-xr-x. 1 root root 679679112 Apr 7 20:14 /usr/lib/debug/lib/modules/5.11.12-300.fc34.x86_64/vmlinux<br> > > [root@localhost ~]# rpm -qf /usr/lib/debug/lib/modules/5.11.12-300.fc34.x86_64/vmlinux<br> > > kernel-debuginfo-5.11.12-300.fc34.x86_64<br> > ><br> > > NB: last fc35 does not work too.<br> > ><br> ><br> > Thank you for reporting this issue, Vasily.<br> ><br> > The DWARF-5 caused this failure. I will have a look and try to handle this issue later.<br> ><br> > Thanks.<br> > Lianbo<br> ><br> <br> What's the status of this issue? Is this due to needing updated<br> embedded gdb or something else?<br></blockquote><div><br></div><div>Hi, David</div><div>Thank you for the attention.</div><div>Currently, Fedora kernel has been forced to generate the DWARF4 debuginfo <span style="color:rgb(33,37,41);font-family:"Open Sans";font-size:14px">via the</span></div><span style="color:rgb(33,37,41);font-family:"Open Sans";font-size:14px">CONFIG_DEBUG_INFO_DWARF4 kernel option, see jforbes' comment:</span><div><a href="https://src.fedoraproject.org/rpms/kernel/pull-request/48" target="_blank">https://src.fedoraproject.org/rpms/kernel/pull-request/48</a> </div><div><br></div><div>Once crash gdb is upgraded, the DWARF5 could be enabled again in Fedora kernel.</div><div><br></div><div>BTW: that is a temporary branch, still under tests and it has not been announced yet.</div><div><br></div><div>Thanks.</div><div>Lianbo</div></div></div>