[Solved] vboxsf don't compile on 32bit linux kernel-5.2.21

[biotec]

Hi!

VirtualBox Guest additions (at least 6.0.12 and 6.0.14) fail to fully compile on a 32-bit Linux with kernel 5.2.20 or 5.2.21. The same compile ok on a 64-bit Linux (same version numbers).

Under the 32-bit kernel, vboxguest module compiles ok, but compilation fails when atempting to build the vboxsf module:

Code: Select all

=== Building 'vboxguest' module ===
make[1]: Entering directory '/opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxguest'
make V= CONFIG_MODULE_SIG= -C /lib/modules/5.2.21-porteus/build M=/opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxguest SRCROOT=/opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxguest -j1 modules
make[2]: Entering directory '/usr/src/linux-5.2.21'
  Building modules, stage 2.
  MODPOST 1 modules
make[2]: Leaving directory '/usr/src/linux-5.2.21'
make[1]: Leaving directory '/opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxguest'

=== Building 'vboxsf' module ===
make[1]: Entering directory '/opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxsf'
make V= CONFIG_MODULE_SIG= -C /lib/modules/5.2.21-porteus/build M=/opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxsf SRCROOT=/opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxsf -j1 modules
make[2]: Entering directory '/usr/src/linux-5.2.21'
  CC [M]  /opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxsf/regops.o
/opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxsf/regops.c: In function 'vbsf_lock_kernel_pages':
/opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxsf/regops.c:1388:1: error: unsupported size for integer register
 1388 | }
      | ^
make[3]: *** [scripts/Makefile.build:279: /opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxsf/regops.o] Error 1
make[2]: *** [Makefile:1597: _module_/opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxsf] Error 2
make[2]: Leaving directory '/usr/src/linux-5.2.21'
make[1]: *** [/opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxsf/Makefile-footer.gmk:111: vboxsf] Error 2
make[1]: Leaving directory '/opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/vboxsf'
make: *** [Makefile:48: vboxsf] Error 1

(vboxvideo module can be built successfully with 'make vboxvideo' too, from /opt/VBoxGuestAdditions-6.0.14/src/vboxguest-6.0.14/).

Any idea what is wrong?

[biotec]

Found the solution myself.
You need to add

Code: Select all

VBOXMOD_CFLAGS += -O2

to the Makefile in the vboxsf source directory. Not required to compile on a 64-bit guest.
It would be nice if this could be fixed upstream. Apparently it is not a new problem.

[socratis]

'biotec', this is interesting, because AFAIK, the "O" flag is just a different optimization level. Can you give some context about your setup? What's the guest for example? I don't remember the GAs compiling giving such an output as in your original message, could you explain that?

I'm going to mark this thread as [Solved] in any event, and I'll notify the devs as well. Thank you for the feedback and the solution!