[vbox-dev] Guest additions kernel module compilation error on CentOS 8 Stream guest

[Frank Batschulat]

Thanks Mark, I'll look into that, follow up:

Ticket #19391 (assigned defect)
Guest additions kernel module compilation error on CentOS 8 Stream guest
https://www.virtualbox.org/ticket/19391

On Tue, 10 Mar 2020 10:05:27 +0100, Mark Thebridge  
<Mark.Thebridge at metaswitch.com> wrote:

> Hi,
>
> The latest version of the Guest Additions (both 6.1.4 and master) fail  
> to compile the kernel modules on a CentOS 8.1 guest using kernel  
> 4.18.0-177.el8.x86_64 - the latest kernel available through the  
> "Streams" release (which allows CentOS users to get early versions of  
> packages that will be in the next minor release).
>
> I've provided an initial patch that partly fixes this below (authored by  
> me, released under the MIT license).  With this patch the video module  
> compiles and works  - *but* I'm not sure exactly what the #include  
> guards ought to be.  We can't actually test for RHEL_81 being defined,  
> because then guest additions will stop compiling for anyone on the main  
> RHEL/CentOS 8.1 release.  Unfortunately there's no real way I can see to  
> tell if we are using at least  4.18.0-177.el8 (which needs these  
> changes) or an earlier 8.1 kernel.  The kernel release number is  
> available as the RHEL_RELEASE #define in the kernel tree, but that's a  
> string, not an integer, and the C pre-processor can't do string  
> comparisons.  I think we'd need some Makefile enhancements to pass in  
> extra #defines, but not sure exactly where in the Makefiles those should  
> live...
>
> Even if this isn't fixed for CentOS 8 Streams guests, this patch will  
> almost certainly be needed for RHEL/CentOS 8.2 when that comes out
>
> Thanks,
> Mark
>
> diff -uNr -w a/vbox_fb.c b/vbox_fb.c
> --- a/vbox_fb.c 2020-02-18 15:31:10.000000000 +0000
> +++ b/vbox_fb.c 2020-03-03 16:33:07.197239177 +0000
> @@ -335,14 +331,14 @@
>      info->apertures->ranges[0].base = pci_resource_start(dev->pdev, 0);
>      info->apertures->ranges[0].size = pci_resource_len(dev->pdev, 0);
>
> -#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 2, 0)
> +#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 2, 0) || defined(RHEL_81)
>      drm_fb_helper_fill_info(info, &fbdev->helper, sizes);
> #elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0) || defined(RHEL_75)
>      drm_fb_helper_fill_fix(info, fb->pitches[0], fb->format->depth);
> #else
>      drm_fb_helper_fill_fix(info, fb->pitches[0], fb->depth);
> #endif
> -#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 2, 0)
> +#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 2, 0) && !defined(RHEL_81)
>      drm_fb_helper_fill_var(info, &fbdev->helper, sizes->fb_width,
>                        sizes->fb_height);
> #endif
> diff -uNr -w a/vbox_ttm.c b/vbox_ttm.c
> --- a/vbox_ttm.c 2020-02-14 11:35:05.000000000 +0000
> +++ b/vbox_ttm.c 2020-03-03 16:33:07.199239341 +0000
> @@ -312,7 +308,7 @@
> #endif
> #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 5, 0)
>                                   dev->vma_offset_manager,
> -#elif LINUX_VERSION_CODE < KERNEL_VERSION(5, 2, 0)
> +#elif LINUX_VERSION_CODE < KERNEL_VERSION(5, 2, 0) && !defined(RHEL_81)
>                       DRM_FILE_PAGE_OFFSET,
> #endif
>                       true);


-- 
frankB

Oracle Virtualbox Development