[21.04 FEAT] Add kernel debug infos for decompressor stage to kernel-debug package

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In order to be able to debug kernel crashes during the early decompressing phase, it would be useful to add the vmlinux file from the decompressor stage to the kernel-debug deb package.
The file is located in arch/s390/boot/compressed/vmlinux.
There are plans to make the kernel relocatable and move more things to the decompressor stage, which would be easier to debug in case of a problem if we have this file in the debug info package.

Business Case:
Increase problem determination / serviceability.

[Frank Heimes (fheimes)]

Would you please share more information about the patches and (at least the plan) when they will be available upstream?

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2021-02-19 08:08 EDT-------
There are no patches required upstream - that feature is just about adding arch/s390/boot/compressed/vmlinux to the kernel debug package. So i think only the rules file of that package needs to be modified. Maybe a diff explains it better:

--- ./debian/rules.d/2-binary-arch.mk.ori 2021-02-19 13:09:46.466852048 +0000
+++ ./debian/rules.d/2-binary-arch.mk 2021-02-19 12:54:32.056342686 +0000
@@ -279,6 +279,10 @@
# Debug image is simple
install -m644 -D $(builddir)/build-$*/vmlinux \
$(dbgpkgdir)/usr/lib/debug/boot/vmlinux-$(abi_release)-$*
+ifeq ($(arch),s390x)
+ install -m644 -D $(builddir)/build-$*/arch/s390/boot/compressed/vmlinux \
+ $(dbgpkgdir)/usr/lib/debug/boot/vmlinux-$(abi_release)-$*.decompressor
+endif
$(build_cd) $(kmake) $(build_O) modules_install $(vdso) \
INSTALL_MOD_PATH=$(dbgpkgdir)/usr/lib/debug
# Add .gnu_debuglink sections only after all/DKMS modules are built.

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------- Comment From <email address hidden> 2021-02-23 06:23 EDT-------
@Canonical, anything missing here, from your point of view, for integration?

[Frank Heimes (fheimes)]

An initial look at this tells me that it should be fine.
But I have to hand over to the kernel team for a final decision.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 5.11.0-14.15

---------------
linux (5.11.0-14.15) hirsute; urgency=medium

  * hirsute/linux: 5.11.0-14.15 -proposed tracker (LP: #1923103)

  * Packaging resync (LP: #1786013)
    - update dkms package versions

  * Include Infiniband Peer Memory interface (LP: #1923104)
    - SAUCE: RDMA/core: Introduce peer memory interface

  * Hirsute update: v5.11.12 upstream stable release (LP: #1923069)
    - arm64: mm: correct the inside linear map range during hotplug check
    - virtiofs: Fail dax mount if device does not support it
    - ext4: shrink race window in ext4_should_retry_alloc()
    - ext4: fix bh ref count on error paths
    - fs: nfsd: fix kconfig dependency warning for NFSD_V4
    - rpc: fix NULL dereference on kmalloc failure
    - iomap: Fix negative assignment to unsigned sis->pages in
      iomap_swapfile_activate
    - ASoC: rt1015: fix i2c communication error
    - ASoC: rt5640: Fix dac- and adc- vol-tlv values being off by a factor of 10
    - ASoC: rt5651: Fix dac- and adc- vol-tlv values being off by a factor of 10
    - ASoC: sgtl5000: set DAP_AVC_CTRL register to correct default value on probe
    - ASoC: es8316: Simplify adc_pga_gain_tlv table
    - ASoC: soc-core: Prevent warning if no DMI table is present
    - ASoC: cs42l42: Fix Bitclock polarity inversion
    - ASoC: cs42l42: Fix channel width support
    - ASoC: cs42l42: Fix mixer volume control
    - ASoC: cs42l42: Always wait at least 3ms after reset
    - NFSD: fix error handling in NFSv4.0 callbacks
    - ASoC: mediatek: mt8192: fix tdm out data is valid on rising edge
    - kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing
    - vhost: Fix vhost_vq_reset()
    - io_uring: fix ->flags races by linked timeouts
    - io_uring: halt SQO submission on ctx exit
    - scsi: st: Fix a use after free in st_open()
    - scsi: qla2xxx: Fix broken #endif placement
    - staging: comedi: cb_pcidas: fix request_irq() warn
    - staging: comedi: cb_pcidas64: fix request_irq() warn
    - ASoC: rt5659: Update MCLK rate in set_sysclk()
    - ASoC: rt711: add snd_soc_component remove callback
    - thermal/core: Add NULL pointer check before using cooling device stats
    - locking/ww_mutex: Simplify use_ww_ctx & ww_ctx handling
    - locking/ww_mutex: Fix acquire/release imbalance in
      ww_acquire_init()/ww_acquire_fini()
    - nvmet-tcp: fix kmap leak when data digest in use
    - io_uring: imply MSG_NOSIGNAL for send[msg]()/recv[msg]() calls
    - Revert "PM: ACPI: reboot: Use S5 for reboot"
    - nouveau: Skip unvailable ttm page entries
    - static_call: Align static_call_is_init() patching condition
    - ext4: do not iput inode under running transaction in ext4_rename()
    - io_uring: call req_set_fail_links() on short send[msg]()/recv[msg]() with
      MSG_WAITALL
    - net: mvpp2: fix interrupt mask/unmask skip condition
    - mptcp: deliver ssk errors to msk
    - mptcp: fix poll after shutdown
    - mptcp: init mptcp request socket earlier
    - mptcp: add a missing retransmission timer scheduling
    - flow_dissector: fix TTL and TOS dissection on IPv4 fragments
    - mptcp: fix DATA_FIN processing f...

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------- Comment From <email address hidden> 2021-04-14 02:14 EDT-------
IBM Bugzilla status->closed, Fix Released with hirsuite