Hello all, I've upgraded my Centos 8 VM to the latest kernel (4.18.0-193.6.3.el8_2.x86_64). I have then installed the kernel-debug packages (and dependencies), as suggested below. Now, I have following kernels in /boot: - vmlinuz-4.18.0-193.6.3.el8_2.x86_64 - vmlinuz-4.18.0-193.6.3.el8_2.x86_64+debug

And a vmlinuz file in /lib/modules/4.18.0-193.6.3.el8_2.x86_64+debug Then, I reboot the VM on this latest kernel and extracted the vmlinux files with the extract-vmlinux script from a CentOS 4.18.0 kernel source tree. A last, the 'echo c > /proc/sysrq-trigger' creates the /var/crash/vmcore file. Exporting the vmcore, vmlinux-4.18.0-193.6.3.el8_2.x86_64+debug and vmlinux (from /lib/modules) on another CentOS machine and executing: /usr/bin/crash -d 15 vmlinux-4.18.0-193.6.3.el8_2.x86_64+debug vmcore returns: crash: vmlinux-4.18.0-193.6.3.el8_2.x86_64+debug: no .gnu_debuglink section Note: same result when using the exported vmlinux from /lib/modules directory. Still not driving me nut... but not far away... To be continued... Thanks. Best regards, Patrick -----Message d'origine----- De : crash-utility-bounces(a)redhat.com [mailto:crash-utility-bounces@redhat.com] De la part de Kazuhito Hagio Envoyé : jeudi 9 juillet 2020 07:00 À : Discussion list for crash utility usage, maintenance and development <crash-utility(a)redhat.com&gt; Objet : EXT: Re: [Crash-utility] EXT: Re: crash start in CentOS 8 ** External email - Please consider with caution ** Hi Patrick, > OSRELEASE=4.18.0-147.el8.x86_64 Hmm, I think you might boot the virtual machine with the original (unmodified) CentOS 8 kernel, because the address of init_uts_ns looks to be its one: > SYMBOL(init_uts_ns)=ffffffffb5a12540 > KERNELOFFSET=33800000 I happen to have a CentOS 8 machine.. # grep 'D init_uts_ns' /boot/System.map-4.18.0-147.el8.x86_64 ffffffff82212540 D init_uts_ns # printf "%16llx\n" $(( 0xffffffff82212540 + 0x33800000 )) ffffffffb5a12540 while your vmcore.debuginfo has the different address: > <readmem: ffffffffb7221d64, KVADDR, "init_uts_ns", 390, (ROE), > d71b7c> So, which kernel do you actually want to use on the virtual machine? (1) The original CentOS 8 kernel (2) The kernel you built If it's (1), you can just install the kernel-debuginfo package corresponding to the original CentOS 8 kernel into the machine on which you want to analyze vmcores and execute: # crash /usr/lib/debug/lib/modules/4.18.0-147.el8.x86_64/vmlinux vmcore If it's (2), you need to boot the VM with the kernel and make a crash. Could you check this first? Thanks, Kazu On Mon, Jul 6, 2020 at 10:03 PM Agrain Patrick <patrick.agrain(a)al-enterprise.com&gt; wrote: > > Hello all, > > Back on this topic: > I compiled a kernel with debuginfo on the Virtual Machine with CentOS8. > I made a crash on this same VM. > I transferred the vmcore and vmlinux.debuginfo files on another CentOS8 baremetal machine. > > The command '/usr/bin/crash -d 15 vmlinux.debuginfo vmcore' produces following logs, but still failing to get the crash> prompt. > Still KASLR ? > > Thanks in advance for any information. > Best regards, > Patrick Agrain > > -- Logs: > crash 7.2.6-2.el8 > Copyright (C) 2002-2019 Red Hat, Inc. > Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation Copyright (C) > 1999-2006 Hewlett-Packard Co Copyright (C) 2005, 2006, 2011, 2012 > Fujitsu Limited Copyright (C) 2006, 2007 VA Linux Systems Japan K.K. > Copyright (C) 2005, 2011 NEC Corporation Copyright (C) 1999, 2002, > 2007 Silicon Graphics, Inc. > Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc. > This program is free software, covered by the GNU General Public > License, and you are welcome to change it and/or distribute copies of > it under certain conditions. Enter "help copying" to see the conditions. > This program has absolutely no warranty. Enter "help warranty" for details. > > compressed kdump: header->utsname.machine: x86_64 compressed kdump: > memory bitmap offset: 2000 > diskdump_data: > filename: vmcore > flags: 6 (KDUMP_CMPRS_LOCAL|ERROR_EXCLUDED) > dfd: 3 > ofp: 0 > machine_type: 62 (EM_X86_64) > > header: 212b5d0 > signature: "KDUMP " > header_version: 6 > utsname: > sysname: Linux > nodename: localhost.localdomain > release: 4.18.0-147.el8.x86_64 > version: #1 SMP Wed Dec 4 21:51:45 UTC 2019 > machine: x86_64 > domainname: (none) > timestamp: > tv_sec: 5ee72d23 > tv_usec: 0 > status: 2 (DUMP_DH_COMPRESSED_LZO) > block_size: 4096 > sub_hdr_size: 1 > bitmap_blocks: 32 > max_mapnr: 524288 > total_ram_blocks: 0 > device_blocks: 0 > written_blocks: 0 > current_cpu: 0 > nr_cpus: 1 > tasks[nr_cpus]: 0 > > sub_header: 0 (n/a) > > sub_header_kdump: 212c5e0 > phys_base: 7c00000 > dump_level: 31 (0x1f) (DUMP_EXCLUDE_ZERO|DUMP_EXCLUDE_CACHE|DUMP_EXCLUDE_CACHE_PRI|DUMP_EXCLUDE_USER_DATA|DUMP_EXCLUDE_FREE) > split: 0 > start_pfn: (unused) > end_pfn: (unused) > offset_vmcoreinfo: 4580 (0x11e4) > size_vmcoreinfo: 2025 (0x7e9) > OSRELEASE=4.18.0-147.el8.x86_64 > PAGESIZE=4096 > SYMBOL(init_uts_ns)=ffffffffb5a12540 > SYMBOL(node_online_map)=ffffffffb5c06d60 > SYMBOL(swapper_pg_dir)=ffffffffb5a0a000 > SYMBOL(_stext)=ffffffffb4800000 > SYMBOL(vmap_area_list)=ffffffffb5ad2a90 > SYMBOL(mem_section)=ffff89df7ffd2000 > LENGTH(mem_section)=2048 > SIZE(mem_section)=16 > OFFSET(mem_section.section_mem_map)=0 > SIZE(page)=64 > SIZE(pglist_data)=171968 > SIZE(zone)=1472 > SIZE(free_area)=88 > SIZE(list_head)=16 > SIZE(nodemask_t)=128 > OFFSET(page.flags)=0 > OFFSET(page._refcount)=52 > OFFSET(page.mapping)=24 > OFFSET(page.lru)=8 > OFFSET(page._mapcount)=48 > OFFSET(page.private)=40 > OFFSET(page.compound_dtor)=16 > OFFSET(page.compound_order)=17 > OFFSET(page.compound_head)=8 > OFFSET(pglist_data.node_zones)=0 > OFFSET(pglist_data.nr_zones)=171232 > OFFSET(pglist_data.node_start_pfn)=171240 > OFFSET(pglist_data.node_spanned_pages)=171256 > OFFSET(pglist_data.node_id)=171264 > OFFSET(zone.free_area)=192 > OFFSET(zone.vm_stat)=1296 > OFFSET(zone.spanned_pages)=112 > OFFSET(free_area.free_list)=0 > OFFSET(list_head.next)=0 > OFFSET(list_head.prev)=8 > OFFSET(vmap_area.va_start)=0 > OFFSET(vmap_area.list)=48 > LENGTH(zone.free_area)=11 > SYMBOL(log_buf)=ffffffffb5a5a280 > SYMBOL(log_buf_len)=ffffffffb5a5a27c > SYMBOL(log_first_idx)=ffffffffb633a770 > SYMBOL(clear_idx)=ffffffffb633a744 > SYMBOL(log_next_idx)=ffffffffb633a760 > SIZE(printk_log)=16 > OFFSET(printk_log.ts_nsec)=0 > OFFSET(printk_log.len)=8 > OFFSET(printk_log.text_len)=10 > OFFSET(printk_log.dict_len)=12 > LENGTH(free_area.free_list)=5 > NUMBER(NR_FREE_PAGES)=0 > NUMBER(PG_lru)=5 > NUMBER(PG_private)=12 > NUMBER(PG_swapcache)=9 > NUMBER(PG_swapbacked)=18 > NUMBER(PG_slab)=8 > NUMBER(PG_hwpoison)=22 > NUMBER(PG_head_mask)=32768 > NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE)=-129 > NUMBER(HUGETLB_PAGE_DTOR)=2 > NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE)=-257 > NUMBER(phys_base)=130023424 > SYMBOL(init_top_pgt)=ffffffffb5a0a000 > NUMBER(pgtable_l5_enabled)=0 > SYMBOL(node_data)=ffffffffb5c02580 > LENGTH(node_data)=1024 > KERNELOFFSET=33800000 > NUMBER(KERNEL_IMAGE_SIZE)=1073741824 > NUMBER(sme_mask)=0 > CRASHTIME=1592208675 > offset_note: 4200 (0x1068) > size_note: 2408 (0x968) > notes_buf: 2129460 > num_vmcoredd_notes: 0 > num_prstatus_notes: 1 > notes[0]: 2129460 (NT_PRSTATUS) > si.signo: 0 si.code: 0 si.errno: 0 > cursig: 0 sigpend: 0 sighold: 0 > pid: 2846 ppid: 0 pgrp: 0 sid:0 > utime: 0.000000 stime: 0.000000 > cutime: 0.000000 cstime: 0.000000 > ORIG_RAX: ffffffffffffffff fpvalid: 0 > R15: 0000000000000000 R14: 00005616bb1208f0 > R13: ffffffffb5b36fc0 R12: 0000000000000000 > RBP: 0000000000000004 RBX: 0000000000000063 > R11: 6873617263206120 R10: 7265676769725420 > R9: 54203a2071527379 R8: 000000000000056a > RAX: ffffffffb4d12d10 RCX: 0000000000000006 > RDX: 0000000000000000 RSI: 0000000000000086 > RDI: 0000000000000063 RIP: ffffffffb4d12d22 > RFLAGS: 0000000000010246 RSP: ffffb03903147e80 > FS_BASE: 00007f5d6e06f740 > GS_BASE: 0000000000000000 > CS: 0010 SS: 0018 DS: 0000 > ES: 0000 FS: 0000 GS: 0000 > snapshot_task: 0 > num_qemu_notes: 0 > NOTE offsets: 1068 (NT_PRSTATUS) > offset_eraseinfo: 0 (0x0) > size_eraseinfo: 0 (0x0) > start_pfn_64: (unused) > end_pfn_64: (unused) > max_mapnr_64: 524288 (0x80000) > > data_offset: 22000 > block_size: 4096 > block_shift: 12 > bitmap: 212f190 > bitmap_len: 131072 > max_mapnr: 524288 (0x80000) > dumpable_bitmap: 7f937ad93010 > byte: 0 > bit: 0 > compressed_page: 212d5f0 > curbufptr: 0 > > page_cache_hdr[0]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 217f1d0 > pg_hit_count: 0 > page_cache_hdr[1]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 21801d0 > pg_hit_count: 0 > page_cache_hdr[2]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 21811d0 > pg_hit_count: 0 > page_cache_hdr[3]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 21821d0 > pg_hit_count: 0 > page_cache_hdr[4]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 21831d0 > pg_hit_count: 0 > page_cache_hdr[5]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 21841d0 > pg_hit_count: 0 > page_cache_hdr[6]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 21851d0 > pg_hit_count: 0 > page_cache_hdr[7]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 21861d0 > pg_hit_count: 0 > page_cache_hdr[8]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 21871d0 > pg_hit_count: 0 > page_cache_hdr[9]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 21881d0 > pg_hit_count: 0 > page_cache_hdr[10]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 21891d0 > pg_hit_count: 0 > page_cache_hdr[11]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 218a1d0 > pg_hit_count: 0 > page_cache_hdr[12]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 218b1d0 > pg_hit_count: 0 > page_cache_hdr[13]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 218c1d0 > pg_hit_count: 0 > page_cache_hdr[14]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 218d1d0 > pg_hit_count: 0 > page_cache_hdr[15]: > pg_flags: 0 () > pg_addr: 0 > pg_bufptr: 218e1d0 > pg_hit_count: 0 > > page_cache_buf: 217f1d0 > evict_index: 0 > evictions: 0 > accesses: 0 > cached_reads: 0 > valid_pages: 212a3b0 > readmem: read_diskdump() > KASLR: > _stext from vmlinux.debuginfo: ffffffff81000000 > _stext from vmcoreinfo: ffffffffb4800000 > relocate: 33800000 (824MB) > crash: pv_init_ops exists: ARCH_PVOPS > VMCOREINFO: NUMBER(phys_base): 130023424 -> 7c00000 gdb > vmlinux.debuginfo GNU gdb (GDB) 7.6 Copyright (C) 2013 Free Software > Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later > <http://gnu.org/licenses/gpl.html> > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. Type "show copying" > and "show warranty" for details. > This GDB was configured as "x86_64-unknown-linux-gnu"... > GETBUF(328 -> 0) > GETBUF(1500 -> 1) > > WARNING: kernel relocated [824MB]: patching 109676 gdb minimal_symbol > values > > FREEBUF(1) > FREEBUF(0) > <readmem: ffffffffb70df958, KVADDR, "page_offset_base", 8, (FOE|Q), > d8b948> > <read_diskdump: addr: ffffffffb70df958 paddr: 3ecdf958 cnt: 8> > read_diskdump: paddr/pfn: 3ecdf958/3ecdf -> cache physical page: > 3ecdf000 > GETBUF(328 -> 0) > FREEBUF(0) > GETBUF(1024 -> 0) > <readmem: ffffffffb7f0c5e0, KVADDR, "possible", 1024, (ROE), fcd120> > <read_diskdump: addr: ffffffffb7f0c5e0 paddr: 3fb0c5e0 cnt: 1024> > read_diskdump: PAGE_EXCLUDED: paddr/pfn: 3fb0c5e0/3fb0c > crash: page excluded: kernel virtual address: ffffffffb7f0c5e0 type: "possible" > WARNING: cannot read cpu_possible_map > <readmem: ffffffffb7f0bde0, KVADDR, "present", 1024, (ROE), fcd120> > <read_diskdump: addr: ffffffffb7f0bde0 paddr: 3fb0bde0 cnt: 544> > read_diskdump: PAGE_EXCLUDED: paddr/pfn: 3fb0bde0/3fb0b > crash: page excluded: kernel virtual address: ffffffffb7f0bde0 type: "present" > WARNING: cannot read cpu_present_map > <readmem: ffffffffb7f0c1e0, KVADDR, "online", 1024, (ROE), fcd120> > <read_diskdump: addr: ffffffffb7f0c1e0 paddr: 3fb0c1e0 cnt: 1024> > read_diskdump: PAGE_EXCLUDED: paddr/pfn: 3fb0c1e0/3fb0c > crash: page excluded: kernel virtual address: ffffffffb7f0c1e0 type: "online" > WARNING: cannot read cpu_online_map > <readmem: ffffffffb7f0b9e0, KVADDR, "active", 1024, (ROE), fcd120> > <read_diskdump: addr: ffffffffb7f0b9e0 paddr: 3fb0b9e0 cnt: 1024> > read_diskdump: PAGE_EXCLUDED: paddr/pfn: 3fb0b9e0/3fb0b > crash: page excluded: kernel virtual address: ffffffffb7f0b9e0 type: "active" > WARNING: cannot read cpu_active_map > FREEBUF(0) > <readmem: ffffffffb731a5b0, KVADDR, "pv_init_ops", 8, (ROE), > 7ffd3655d640> > <read_diskdump: addr: ffffffffb731a5b0 paddr: 3ef1a5b0 cnt: 8> > read_diskdump: paddr/pfn: 3ef1a5b0/3ef1a -> cache physical page: > 3ef1a000 > GETBUF(328 -> 0) > FREEBUF(0) > GETBUF(328 -> 0) > FREEBUF(0) > <readmem: ffffffffb9bad1d0, KVADDR, "shadow_timekeeper xtime_sec", 8, > (ROE), 7ffd3655d5f0> > <read_diskdump: addr: ffffffffb9bad1d0 paddr: 417ad1d0 cnt: 8> > read_diskdump: PAGE_EXCLUDED: paddr/pfn: 417ad1d0/417ad > crash: page excluded: kernel virtual address: ffffffffb9bad1d0 type: "shadow_timekeeper xtime_sec" > xtime timespec.tv_sec: 900f27: Mon Apr 20 07:31:03 1970 > <readmem: ffffffffb7221d64, KVADDR, "init_uts_ns", 390, (ROE), > d71b7c> > <read_diskdump: addr: ffffffffb7221d64 paddr: 3ee21d64 cnt: 390> > read_diskdump: paddr/pfn: 3ee21d64/3ee21 -> cache physical page: > 3ee21000 > utsname: > sysname: > nodename: > release: > version: > machine: > domainname: > base kernel version: 0.0.0 > <readmem: ffffffffb6a016c0, KVADDR, "accessible check", 8, (ROE|Q), > 7ffd3655af30> > <read_diskdump: addr: ffffffffb6a016c0 paddr: 3e6016c0 cnt: 8> > read_diskdump: PAGE_EXCLUDED: paddr/pfn: 3e6016c0/3e601 > crash: page excluded: kernel virtual address: ffffffffb6a016c0 type: "accessible check" > crash: vmlinux.debuginfo and vmcore do not match! > > Usage: > > crash [OPTION]... NAMELIST MEMORY-IMAGE[@ADDRESS] (dumpfile form) > crash [OPTION]... [NAMELIST] (live system form) > > Enter "crash -h" for details. > -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility