why signed kernels call update-grub?

[Dimitri John Ledkov]

Looking at the postrm of linux-signed-image-* it looks very different from linux-image-* ones

$ cat linux-signed-image-3.16.0-20-generic.postrm
#!/bin/sh -e

kernel='vmlinuz-3.16.0-20-generic'

case "$0-$1" in
*.postinst-configure)
 rm -f /boot/$kernel.efi.signed
 cp /boot/$kernel /boot/$kernel.efi.signed
 sbattach --attach /usr/lib/linux/$kernel.efi.signature /boot/$kernel.efi.signed

 if which update-grub >/dev/null 2>&1; then
  update-grub || true
 fi
 ;;
*.postrm-remove)
 rm -f /boot/$kernel.efi.signed

 if which update-grub >/dev/null 2>&1; then
  update-grub || true
 fi
 ;;
esac

Why does it call update-grub direct instead of calling into /etc/kernel like the normal kernel packages do?

In essence on amd64 the amount of calls to update-grub is duplicated on both installation and removal of kernel packages, since -signed version is installed by default. Why can't we just install signed version and make it modify kernel image in-place?

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: linux-signed-generic 3.16.0.25.26
ProcVersionSignature: Ubuntu 3.16.0-25.33-generic 3.16.7
Uname: Linux 3.16.0-25-generic x86_64
ApportVersion: 2.14.7-0ubuntu8
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: xnox 4525 F.... pulseaudio
CurrentDesktop: Unity
Date: Tue Nov 25 23:08:41 2014
HibernationDevice: RESUME=UUID=2bf263f1-753f-4b2e-92a6-b00381515e0c
InstallationDate: Installed on 2012-01-12 (1048 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130318)
MachineType: Gigabyte Technology Co., Ltd. To be filled by O.E.M.
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.16.0-25-generic.efi.signed root=UUID=6669d411-80c3-41cc-a629-ad84e1ee6854 ro quiet splash nomdmonddf nomdmonisw crashkernel=384M-:128M nomdmonddf nomdmonisw crashkernel=384M-:128M nomdmonddf nomdmonisw crashkernel=384M-:128M nomdmonddf nomdmonisw crashkernel=384M-:128M nomdmonddf nomdmonisw crashkernel=384M-:128M nomdmonddf nomdmonisw crashkernel=384M-:128M nomdmonddf nomdmonisw crashkernel=384M-:128M nomdmonddf nomdmonisw crashkernel=384M-:128M vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.16.0-25-generic N/A
 linux-backports-modules-3.16.0-25-generic N/A
 linux-firmware 1.138
RfKill:

SourcePackage: linux
SystemImageInfo:
 current build number: 0
 device name: ?
 channel: daily
 last update: Unknown
UpgradeStatus: No upgrade log present (probably fresh install)
WifiSyslog:

dmi.bios.date: 08/13/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: F18g
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: Z77X-D3H
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF18g:bd08/13/2013:svnGigabyteTechnologyCo.,Ltd.:pnTobefilledbyO.E.M.:pvrTobefilledbyO.E.M.:rvnGigabyteTechnologyCo.,Ltd.:rnZ77X-D3H:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.name: To be filled by O.E.M.
dmi.product.version: To be filled by O.E.M.
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

[Brad Figg (brad-figg)]

This change was made by a bot.

[Andy Whitcroft (apw)]

We cannot modify the kernel in place because that is a file belonging to another package. We need to re-run grub because it is going to update the filename in the grub configuration. We are avoiding the whole of /etc/kernel/* to avoid rebuilding the initramfs yet again after install. Much of this "doing things over and over" will be resolved when the fixes to use triggers in grub2 and initramfs-tools are in, but those are stuck waiting on a console-setup update.

[Andy Whitcroft (apw)]

As we have separate work items to switch to using triggers, this one can be closed out as Won't Fix.