MTL-2454 kdump 1.9 fixes

[rustydb]

Summary and Scope

• Fixes: MTL-2454
• Relates to: MTL-2451

Issue Type

• RFE Pull Request

My testing used the following KDUMP_SAVEDIR:

ncn-w003:~ # grep KDUMP_SAVEDIR /etc/sysconfig/kdump
KDUMP_SAVEDIR="file:///run/initramfs/overlayfs/var/crash"

A booted system with the correct links:

ncn-w003:~ # ls -l /run/initramfs/overlayfs/
total 4
drwxr-xr-x 4 root root  82 Oct  7 22:01 1.6.0-alpha.67
-rw-r--r-- 1 root root 297 Oct  7 22:01 README.txt
lrwxrwxrwx 1 root root  75 Oct  7 22:01 boot -> ./1.6.0-alpha.67/overlay-SQFSRAID-ca2d1e34-91ad-4ac5-ac45-323302769957/boot
drwxr-xr-x 2 root root  19 Oct  7 22:01 var
ncn-w003:~ # ls -l /run/initramfs/overlayfs/var/crash
lrwxrwxrwx 1 root root 81 Oct  7 22:01 /run/initramfs/overlayfs/var/crash -> ../1.6.0-alpha.67/overlay-SQFSRAID-ca2d1e34-91ad-4ac5-ac45-323302769957/var/crash

Triggered crash (observes MTL-2494 but continues due to KDUMP_CONTINUE_ON_ERROR="true")

ncn-w003:~ # echo c >/proc/sysrq-trigger
[  492.519254][T19050] sysrq: Trigger a crash
[  492.523388][T19050] Kernel panic - not syncing: sysrq triggered crash
[  492.529839][T19050] CPU: 36 PID: 19050 Comm: bash Kdump: loaded Tainted: G           OE        6.4.0-150600.23.17-default #1 SLE15-SP6 5eff937aa9559314e63d74eec60fba157a5dbfd6
[  492.545480][T19050] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0016.C0001.032120230338 03/21/2023
[  492.557125][T19050] Call Trace:
[  492.560277][T19050]  <TASK>
[  492.563079][T19050]  dump_stack_lvl+0x57/0x80
[  492.567452][T19050]  panic+0x109/0x2c0
[  492.571211][T19050]  ? _printk+0x52/0x80
[  492.575138][T19050]  sysrq_handle_crash+0x16/0x20
[  492.579852][T19050]  __handle_sysrq+0x9c/0x170
[  492.584299][T19050]  write_sysrq_trigger+0x2b/0x40
[  492.589089][T19050]  proc_reg_write+0x53/0x80
[  492.593459][T19050]  vfs_write+0xc2/0x380
[  492.597479][T19050]  ? __handle_mm_fault+0xa98/0xba0
[  492.602456][T19050]  ksys_write+0xa5/0xe0
[  492.606474][T19050]  do_syscall_64+0x58/0x80
[  492.610765][T19050]  ? handle_mm_fault+0x196/0x2f0
[  492.615557][T19050]  ? do_user_addr_fault+0x267/0x890
[  492.620619][T19050]  ? exc_page_fault+0x69/0x150
[  492.625244][T19050]  entry_SYSCALL_64_after_hwframe+0x7c/0xe6
[  492.631001][T19050] RIP: 0033:0x7feb08d0c770
[  492.635314][T19050] Code: 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 80 3d b9 c2 0e 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
[  492.654755][T19050] RSP: 002b:00007ffe9c8f38e8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[  492.663020][T19050] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007feb08d0c770
[  492.670846][T19050] RDX: 0000000000000002 RSI: 000056033f4addd0 RDI: 0000000000000001
[  492.678669][T19050] RBP: 000056033f4addd0 R08: 0000000000000000 R09: 0000000000000000
[  492.686494][T19050] R10: 00007feb08bfbf08 R11: 0000000000000202 R12: 0000000000000002
[  492.694320][T19050] R13: 00007feb08deb5c0 R14: 00007feb08de8f60 R15: 000056033f667420
[  492.702149][T19050]  </TASK>
[    0.137853][    T1] [Firmware Bug]: the BIOS has corrupted hw-PMU resources (MSR 38d is b0)
[    5.468765] dracut-cmdline[198]: Warning: Network interface 'mgmt0' does not exist
[    5.484071] dracut-cmdline[198]: Warning: Network interface 'mgmt1' does not exist
[    6.876643][  T502] Module qed is blacklisted
[    6.897257][  T498] Module xhci_hcd is blacklisted
[    7.211103][  T496] Module qed is blacklisted
[    7.212386][  T501] Out of memory: Killed process 501 ((udev-worker)) total-vm:33180kB, anon-rss:5276kB, file-rss:4480kB, shmem-rss:0kB, UID:0 pgtables:84kB oom_score_adj:0
Saved temporary README.txt
Saved dmesg
Copying data                                      : [100.0 %] -           eta: 0s

The dumpfile is saved to STDOUT.

makedumpfile Completed.
Saved vmcore
Saved final README.txt
umount: /kdump/mnt/run/initramfs/overlayfs: not mounted.
umount: /sys/fs/cgroup: target is busy.
umount: /run: target is busy.
umount: /dev: target is busy.
umount: /: not mounted.
Rebooting.
[   64.255613][  T761] reboot: Restarting system

Dump was available at the expected location.

ncn-w003:/var/crash # ll
total 0
drwxr-xr-x 2 root root 51 Oct  7 22:09 2024-10-07-22-09
ncn-w003:/var/crash # cd 2024-10-07-22-09/
ncn-w003:/var/crash/2024-10-07-22-09 # ll
total 972220
-rw-r--r-- 1 root root       313 Oct  7 22:10 README.txt
-rw-r--r-- 1 root root    133722 Oct  7 22:09 dmesg
-rw-r--r-- 1 root root 995413584 Oct  7 22:10 vmcore

Prerequisites

• I have included documentation in my PR (or it is not required)
• I tested this on internal system (if yes, please include results or a description of the test)
• I tested this on a vshasta system (if yes, please include results or a description of the test)

Idempotency

Risks and Mitigations

Backwards compatible with kdump<1.9.