[mainline]kdump fails to save vmcore when crash is manually triggered
Venkat Rao Bagalkote
venkat88 at linux.ibm.com
Thu Apr 23 21:59:10 AEST 2026
Hello!!
IBM CI has reported vmcore save failures when kdump is tested by
triggering a kernel crash via sysrq.
Below are the kernel and tool details:
Upstream kernel version: 7.0.0+
Upstream kernel commit-id: 2e68039281932e6dc37718a1ea7cbb8e2cda42e6
kexec-tools 2.0.32.git
makedumpfile: version 1.7.9 (released on 20 Apr 2026)
Error:
While booting to crash kernel, I see below continous prints in console logs:
[ 0.037177] vmcore: Warning: Zero PT_NOTE entries found
[ 0.037181] vmcore: Warning: Zero PT_NOTE entries found
[ 0.037184] vmcore: Warning: Zero PT_NOTE entries found
[ 0.037186] vmcore: Warning: Zero PT_NOTE entries found
And During vmcore collection, I see below error.
[ 9.948432] systemd[1]: Starting kdump-capture.service - Kdump Vmcore
Save Service...
Starting [0;1;39mkdump-capture.service[0m - Kdump Vmcore
Save Service...
[ 9.992306] kdump[408]: [0;1;38:5:185mKdump is using the default log
level(3).[0m
[ 10.158555] kdump[526]: saving to
/sysroot/var/crash/127.0.0.1-2026-04-23-06:06:27/
[ 10.164060] kdump[531]: saving vmcore-dmesg.txt to
/sysroot/var/crash/127.0.0.1-2026-04-23-06:06:27/
[ 10.198598] kdump[537]: saving vmcore-dmesg.txt complete
[ 10.200376] kdump[539]: saving vmcore
Checking for memory holes : [ 0.0 %] /
Checking for memory holes : [100.0 %] |
Excluding unnecessary pages : [ 6.3 %] \
WARNING: Invalid free page order: pfn=5a45fc, order=64424509439,
max order=12
WARNING: Invalid free page order: pfn=621a02, order=2166518513861132288,
max order=12
WARNING: Invalid free page order: pfn=6697b3, order=6706141453275365419,
max order=12
WARNING: Invalid free page order: pfn=669b5d, order=69335804542976, max
order=12
WARNING: Invalid free page order: pfn=66c5a8,
order=14125543804861677568, max order=12
WARNING: Invalid free page order: pfn=66c661, order=845524441759747, max
order=12
WARNING: Invalid free page order: pfn=67dadc,
order=17224182427472101376, max order=12
WARNING: Invalid free page order: pfn=682b38, order=3103260797896228864,
max order=12
WARNING: Invalid free page order: pfn=682efa,
order=14269216714183933953, max order=12
WARNING: Invalid free page order: pfn=682efe, order=134217728, max order=12
WARNING: Invalid free page order: pfn=68c0a0, order=3031209642551148544,
max order=12
WARNING: Invalid free page order: pfn=69709d,
order=17296239995740225536, max order=12
WARNING: Invalid free page order: pfn=6aa909, order=2166511968028983296,
max order=12
WARNING: Invalid free page order: pfn=6ae921, order=6273236509957029888,
max order=12
WARNING: Invalid free page order: pfn=6c1456,
order=17296239987150290944, max order=12
WARNING: Invalid free page order: pfn=6c35a4,
order=14197601399000268800, max order=12
WARNING: Invalid free page order: pfn=6c5de2, order=2166511933669244928,
max order=12
WARNING: Invalid free page order: pfn=6d58da,
order=17296239987150290944, max order=12
WARNING: Invalid free page order: pfn=6d7987,
order=14557325072076374016, max order=12
WARNING: Invalid free page order: pfn=6dbb95,
order=17944838645085110272, max order=12
WARNING: Invalid free page order: pfn=709d7d, order=6273234623090655232,
max order=12
WARNING: Invalid free page order: pfn=709e11, order=3031203148023726080,
max order=12
WARNING: Invalid free page order: pfn=70c02f, order=6705580187335000064,
max order=12
WARNING: Invalid free page order: pfn=715384,
order=14990794317172375552, max order=12
WARNING: Invalid free page order: pfn=715aef, order=5048255524311662592,
max order=12
WARNING: Invalid free page order: pfn=71a51e, order=6199767839173706752,
max order=12
WARNING: Invalid free page order: pfn=71aab5, order=5048255524311662592,
max order=12
WARNING: Invalid free page order: pfn=732e19, order=28147502510048512,
max order=12
WARNING: Invalid free page order: pfn=739896,
order=17296239987150290944, max order=12
WARNING: Invalid free page order: pfn=73b956,
order=17296239991445258240, max order=12
WARNING: Invalid free page order: pfn=73e043, order=2166511933669244928,
max order=12
WARNING: Invalid free page order: pfn=740049, order=6705582074453032960,
max order=12
WARNING: Invalid free page order: pfn=760109, order=6345294104196284416,
max order=12
WARNING: Invalid free page order: pfn=760260, order=2166511968028983296,
max order=12
WARNING: Invalid free page order: pfn=774eb8, order=3103267236521967616,
max order=12
WARNING: Invalid free page order: pfn=77949f, order=3103260802191196160,
max order=12
WARNING: Invalid free page order: pfn=784ac6, order=1971974104455872,
max order=12
WARNING: Invalid free page order: pfn=785196, order=2166518513861132288,
max order=12
WARNING: Invalid free page order: pfn=790654,
order=14557325072177037312, max order=12
WARNING: Invalid free page order: pfn=792cbe,
order=13837309858646983424, max order=12
WARNING: Invalid free page order: pfn=792dbe,
order=13837309859722035968, max order=12
WARNING: Invalid free page order: pfn=793779,
order=15351363758810792960, max order=12
WARNING: Invalid free page order: pfn=7963af, order=2166511933669244928,
max order=12
WARNING: Invalid free page order: pfn=7bda8a,
order=13837313428760297472, max order=12
WARNING: Invalid free page order: pfn=7bfbfa,
order=14269094696377647104, max order=12
WARNING: Invalid free page order: pfn=7c8498,
order=18088873534452400128, max order=12
WARNING: Invalid free page order: pfn=7d4bf7, order=1441792, max order=12
WARNING: Invalid free page order: pfn=7db498,
order=18088873534452400128, max order=12
WARNING: Invalid free page order: pfn=7dba0d, order=6345292217329909760,
max order=12
WARNING: Invalid free page order: pfn=7dc618, order=3319440018652528640,
max order=12
WARNING: Invalid free page order: pfn=7e8788, order=1113619897082537567,
max order=12
readpage_elf: Attempt to read non-existent page at 0x20000000.
readmem: type_addr: 0, addr:c00c000020000000, size:32768
__exclude_unnecessary_pages: Can't read the buffer of struct page.
create_2nd_bitmap: Can't exclude unnecessary pages.
makedumpfile Failed.
[ 10.687238] kdump[542]: [0;1;31msaving vmcore failed, exitcode:1[0m
[ 10.689073] kdump[544]: [0;1;31msaving vmcore failed[0m
[ 10.699975] kdump[549]: saving the /run/initramfs/kexec-dmesg.log to
/sysroot/var/crash/127.0.0.1-2026-04-23-06:06:27///
[ 10.701749] systemd[1]: [0;1;39mkdump-capture.service: Main process
exited, code=exited, status=1/FAILURE[0m
[ 10.701933] systemd[1]: [0;1;38:5:185mkdump-capture.service: Failed
with result 'exit-code'.[0m
[[0;1;31mFAILED[0m] Failed to start [0;1;39mkdump-capture.service[0m
- Kdump Vmcore Save Service.
[ 10.702090] systemd[1]: [0;1;31mFailed to start
kdump-capture.service - Kdump Vmcore Save Service.[0m
See 'systemctl status kdump-capture.service' for details.
[ 10.702249] systemd[1]: Startup finished in 3.351s (kernel) + 0
(initrd) + 7.350s (userspace) = 10.702s.
[ 10.702388] systemd[1]: kdump-capture.service: Triggering OnFailure=
dependencies.
[ 10.703543] systemd[1]: Stopped target timers.target - Timer Units.
If you happen to fix, this please add below tag.
Reported-by: Venkat Rao Bagalkote <venkat88 at linux.ibm.com>
Regards,
Venkat.
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