v2018.1.x: kernel: collect module symvers for external modules

[ecsv]

Collect module symvers for all external modules to make them available
for modpost. This fixes dependencies for most external modules.

root@ffv-525400123456:/# modinfo batman-adv
module:         /lib/modules/4.4.153/batman-adv.ko
alias:          net-pf-16-proto-16-family-batadv
alias:          rtnl-link-batadv
version:        openwrt-2018.1-5
description:    B.A.T.M.A.N. advanced
author:         Marek Lindner <mareklindner@neomailbox.ch>, Simon Wunderlich <sw@simonwunderlich.de>
license:        GPL
depends:

After:

root@ffv-525400123456:/# modinfo batman-adv
module:         /lib/modules/4.4.153/batman-adv.ko
alias:          net-pf-16-proto-16-family-batadv
alias:          rtnl-link-batadv
version:        openwrt-2018.1-5
description:    B.A.T.M.A.N. advanced
author:         Marek Lindner <mareklindner@neomailbox.ch>, Simon Wunderlich <sw@simonwunderlich.de>
license:        GPL
depends:        libcrc32c,cfg80211

[rubo77]

When was this bug introduced?

[ecsv]

It was triggered by 0bb3742 (which moved the the openwrt-routing feed to a newer commit in the openwrt-18.06 branch). The first gluon release with these commit is v2018.1.2.

The underlying bug (missing dependencies in external kernel modules) is there since the beginning of external kernel modules in LEDE/OpenWrt. Kernel modules before OpenWrt 18.06 usually used workarounds to force loading other kernel modules in the correct order. This kind of WAR was dropped for batman-adv in the openwrt-18.06 branch and its kernel loading mechanism was switched to AutoProbe.

• openwrt/routing@1ba424a

The fix here is a backport of the required OpenWrt-18.06 commit to LEDE 17.01. It is required because gluon uses the openwrt-18.06 branch of openwrt-routing with LEDE 17.01.

[rotanid]

@collimas reported it as working, merging it.
there should be more testers thought, at least one, before we consider a new bugfix release

[heini66]

my er-x is working with this patch and i've got a bat0 interface