Re: [Crash-utility] crash: read error on type: "memory section root table"

Hello, Sorry to cross post on both ML, I'm not sure which one would be the most suitable. Issue on analysis with crash-7.3.1 on a Centos 8 machine: crash: read error: kernel virtual address: ffff8f4fff7fc000  type: "memory section root table" Crash machine has a Rocky Linux 8.5 based kernel with following config options: - CONFIG_RANDOMIZE_BASE=y - CONFIG_RANDOMIZE_MEMORY=y - CONFIG_SPARSEMEM_MANUAL=y - CONFIG_SPARSEMEM=y - CONFIG_SPARSEMEM_EXTREME=y - CONFIG_SPARSEMEM_VMEMMAP_ENABLE=y - CONFIG_KEXEC_CORE=y - CONFIG_KEXEC=y - CONFIG_KEXEC_FILE=y Kexec-tools package is from Centos Stream repo: kexec-tools-2.0.20-68.el8.2.5ale.x86_64 /proc/vmcore is packaged with : /sbin/makedumpfile -D -d 0 -c --message-level 15 /proc/vmcore /tmpd/crashdump-${linux_ver}-${date_time} At kernel panic, I get: Dumping memory to crash partition This may take a while, please wait... makedumpfile: version 1.7.0 (released on 8 Nov 2021) command line: /sbin/makedumpfile -D -d 0 -c --message-level 15 /proc/vmcore /tmpd/crashdump--20220329-1538 sadump: does not have partition header sadump: read dump device as unknown format sadump: unknown format                phys_start         phys_end       virt_start         virt_end LOAD[ 0]          8000000          9a2c000 ffffffff8a400000 ffffffff8be2c000 LOAD[ 1]           100000         3b000000 ffff8f4fc0100000 ffff8f4ffb000000 LOAD[ 2]         3d800000         3e341000 ffff8f4ffd800000 ffff8f4ffe341000 LOAD[ 3]         3ed7b000         3eee2000 ffff8f4ffed7b000 ffff8f4ffeee2000 LOAD[ 4]         3f63a000         3f800000 ffff8f4fff63a000 ffff8f4fff800000 Linux kdump VMCOREINFO   :   OSRELEASE=4.18.0-348.12.2.el8_5-ale   PAGESIZE=4096 page_size    : 4096   SYMBOL(init_uts_ns)=ffffffff8b653600   SYMBOL(node_online_map)=ffffffff8b7630a8   SYMBOL(swapper_pg_dir)=ffffffff8b64c000   SYMBOL(_stext)=ffffffff8a400000   SYMBOL(vmap_area_list)=ffffffff8b6a47a0   SYMBOL(mem_map)=ffffffff8bd25828   SYMBOL(contig_page_data)=ffffffff8b726600   SYMBOL(mem_section)=ffff8f4fff7fc000

  LENGTH(mem_section)=2048   SIZE(mem_section)=16   OFFSET(mem_section.section_mem_map)=0   SIZE(page)=64   SIZE(pglist_data)=5696   SIZE(zone)=1216   SIZE(free_area)=72   SIZE(list_head)=16   SIZE(nodemask_t)=8   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)=4944   OFFSET(pglist_data.node_start_pfn)=4952   OFFSET(pglist_data.node_spanned_pages)=4968   OFFSET(pglist_data.node_id)=4976   OFFSET(zone.free_area)=192   OFFSET(zone.vm_stat)=1104   OFFSET(zone.spanned_pages)=96   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)=40   LENGTH(zone.free_area)=11   SYMBOL(log_buf)=ffffffff8b67d3c0   SYMBOL(log_buf_len)=ffffffff8b67d3bc   SYMBOL(log_first_idx)=ffffffff8bd1a3d8   SYMBOL(clear_idx)=ffffffff8bd1a3a4   SYMBOL(log_next_idx)=ffffffff8bd1a3c8   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)=4  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_head_mask)=32768   NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE)=-129   NUMBER(HUGETLB_PAGE_DTOR)=2   NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE)=-257   SYMBOL(alcatel_dump_info)=ffffffff8b647000   NUMBER(phys_base)=-37748736   SYMBOL(init_top_pgt)=ffffffff8b64c000   NUMBER(pgtable_l5_enabled)=0   KERNELOFFSET=9400000   NUMBER(KERNEL_IMAGE_SIZE)=1073741824   NUMBER(sme_mask)=0   CRASHTIME=1648561077 phys_base    : fffffffffdc00000 (vmcoreinfo) max_mapnr    : 3f800 There is enough free memory to be done in one cycle. Buffer size for the cyclic mode: 65024 page_offset  : ffff8f4fc0000000 (pt_load) num of NODEs : 1 Memory type  : SPARSEMEM_EX                        mem_map        pfn_start          pfn_end mem_map[   0] ffff8f4ffa000000                0             8000 mem_map[   1] ffff8f4ffa200000             8000            10000 mem_map[   2] ffff8f4ffa400000            10000            18000 mem_map[   3] ffff8f4ffa600000            18000            20000 mem_map[   4] ffff8f4ffa800000            20000            28000 mem_map[   5] ffff8f4ffaa00000            28000            30000 mem_map[   6] ffff8f4ffac00000            30000            38000 mem_map[   7] ffff8f4ffae00000            38000            3f800 mmap() is available on the kernel. Copying data                                      : [100.0 %] |           eta: 0s Writing erase info... offset_eraseinfo: ca157f3, size_eraseinfo: 0 The dumpfile is saved to /tmpd/crashdump--20220329-1538. makedumpfile Completed. Rebooting the system... And latest logs from a 'crash -d 7' command are: <.> kernel NR_CPUS: 2 <readmem: ffffffff8bd25820, KVADDR, "high_memory", 8, (FOE), 55e05ecb3608> <read_diskdump: addr: ffffffff8bd25820 paddr: 9925820 cnt: 8> PAGESIZE=4096 mem_section_size = 16384 NR_SECTION_ROOTS = 2048 NR_MEM_SECTIONS = 524288 SECTIONS_PER_ROOT = 256 SECTION_ROOT_MASK = 0xff PAGES_PER_SECTION = 32768 <readmem: ffffffff8bd26db0, KVADDR, "mem_section", 8, (FOE), 7ffdbf96a440> <read_diskdump: addr: ffffffff8bd26db0 paddr: 9926db0 cnt: 8> <readmem: ffff8f4fff7fc000, KVADDR, "memory section root table", 16384, (FOE), 55e06391b840> <read_diskdump: addr: ffff8f4fff7fc000 paddr: 3f7fc000 cnt: 4096> crash: read error: kernel virtual address: ffff8f4fff7fc000  type: "memory section root table" The address (ffff8f4fff7fc000) seems to be inside the LOAD[4] range and is recorded as 'mem_section' with VMCOREINFO.