[meta-oe][PATCH v2] vboxguestdrivers: fix vboxvideo build on kernels lacking drm_fb_helper_alloc_info
Khem Raj <[email protected]>
| Newsgroups | org.openembedded.lists.openembedded-devel |
|---|---|
| Message-ID | <[email protected]> |
Now that KERN_MAJ reflects the target kernel instead of the build host's
uname -r, vboxvideo is actually built for kernels older than 7.x -- and it
does not compile against 6.18.44:
vbox_fb.c:336:16: error: implicit declaration of function 'drm_fb_helper_alloc_info'; did you mean 'drm_fb_helper_fill_info'? [-Wimplicit-function-declaration]
vbox_fb.c:336:14: error: assignment to 'struct fb_info *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
Linux commit 63c971af4036 ("drm/fb-helper: Allocate and release fb_info in a
single place") moved the struct fb_info allocation out of the drivers and into
the DRM core, and made drm_fb_helper_alloc_info() static; drivers now find the
instance ready to use in fb_helper->info by the time their .fbdev_probe
callback runs. vbox_fb.c guards its call with RTLNX_VER_MIN(6,19,0), which is
where the change landed in mainline.
Bumping that version check is not a fix. The commit was pulled into stable as
a Stable-dep-of and therefore appears in the *middle* of several series --
v6.6.151, v6.12.103 and v6.18.44 have all dropped the declaration that
v6.6.150, v6.12.102 and v6.18.43 still carry. No LINUX_VERSION_CODE
comparison can express that, and guessing wrong the other way is worse than a
build failure: on a 6.18.0..6.18.43 kernel fb_helper->info is still NULL when
.fbdev_probe runs, so the driver would dereference NULL at runtime.
So add an escape hatch to vbox_fb.c and let the build system decide. do_compile
greps the kernel headers we are actually compiling against and passes
-DVBOX_NO_DRM_FB_HELPER_ALLOC_INFO through KCFLAGS when the declaration is
gone. KCFLAGS rather than EXTRA_CFLAGS/VBOXMOD_CFLAGS because a command-line
assignment of the latter two would clobber the include paths they carry, while
KCFLAGS is untouched by VirtualBox's makefiles and propagates cleanly into the
nested $(MAKE) -C $(KERN_DIR). Leaving the macro undefined keeps the previous
behaviour, so nothing changes for kernels that still export the function, and
7.x is unaffected -- VBOX_VIDEO_MODULE is empty there and the in-tree
drivers/gpu/drm/vboxvideo driver is used instead.
Verified on qemux86-64 against linux-yocto 6.18.44, from cleansstate:
vboxguest.ko, vboxsf.ko and vboxvideo.ko all build with no modpost warnings,
the -D reaches the vbox_fb.o compile line, kernel-module-vboxvideo ships the
module, and `nm -u vboxvideo.ko` no longer references
drm_fb_helper_alloc_info -- all 155 remaining undefined symbols are exported
by the kernel's Module.symvers.
Signed-off-by: Khem Raj <[email protected]>
---
...-build-decide-if-drm_fb_helper_alloc.patch | 54 +++++++++++++++++++
.../vboxguestdrivers_7.2.14.bb | 45 +++++++++++-----
2 files changed, 87 insertions(+), 12 deletions(-)
create mode 100644 meta-oe/recipes-support/vboxguestdrivers/vboxguestdrivers/0001-vboxvideo-let-the-build-decide-if-drm_fb_helper_alloc.patch
diff --git a/meta-oe/recipes-support/vboxguestdrivers/vboxguestdrivers/0001-vboxvideo-let-the-build-decide-if-drm_fb_helper_alloc.patch b/meta-oe/recipes-support/vboxguestdrivers/vboxguestdrivers/0001-vboxvideo-let-the-build-decide-if-drm_fb_helper_alloc.patch
new file mode 100644
index 0000000000..cf94ce49b9
--- /dev/null
+++ b/meta-oe/recipes-support/vboxguestdrivers/vboxguestdrivers/0001-vboxvideo-let-the-build-decide-if-drm_fb_helper_alloc.patch
@@ -0,0 +1,54 @@
+From: Khem Raj <[email protected]>
+Date: Sat, 23 Aug 2026 00:00:00 -0700
+Subject: [PATCH] vboxvideo: let the build decide if drm_fb_helper_alloc_info()
+ exists
+
+Linux commit 63c971af4036 ("drm/fb-helper: Allocate and release fb_info in
+a single place") moved the struct fb_info allocation out of the drivers and
+into the DRM core, and turned drm_fb_helper_alloc_info() into a static
+function. Drivers now find the instance ready to use in fb_helper->info by
+the time their .fbdev_probe callback runs.
+
+vbox_fb.c guards its drm_fb_helper_alloc_info() call with RTLNX_VER_MIN(6,19,0),
+which is where the change landed in mainline. That is not sufficient: the
+commit was also picked up as a Stable-dep-of and so appeared in the middle of
+several stable series - v6.6.151, v6.12.103 and v6.18.44 all dropped the
+declaration while v6.6.150, v6.12.102 and v6.18.43 still have it. Building
+vboxvideo against any of those kernels fails with
+
+ vbox_fb.c:336:16: error: implicit declaration of function 'drm_fb_helper_alloc_info'; did you mean 'drm_fb_helper_fill_info'? [-Wimplicit-function-declaration]
+ vbox_fb.c:336:14: error: assignment to 'struct fb_info *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
+
+Since LINUX_VERSION_CODE cannot express "somewhere inside 6.6.y/6.12.y/6.18.y",
+add an escape hatch the build system can set once it has looked at the kernel
+headers it is actually compiling against. Leaving
+VBOX_NO_DRM_FB_HELPER_ALLOC_INFO undefined keeps the previous behaviour, so
+this is a no-op for anyone building the way VirtualBox intends.
+
+Upstream-Status: Pending
+
+Signed-off-by: Khem Raj <[email protected]>
+---
+ vboxvideo/vbox_fb.c | 9 ++++++++-
+ 1 file changed, 8 insertions(+), 1 deletion(-)
+
+diff --git a/vboxvideo/vbox_fb.c b/vboxvideo/vbox_fb.c
+index 063be63..7163780 100644
+--- a/vboxvideo/vbox_fb.c
++++ b/vboxvideo/vbox_fb.c
+@@ -330,7 +330,14 @@ int vboxfb_create(struct drm_fb_helper *helper,
+ return ret;
+ }
+
+-#if RTLNX_VER_MIN(6,19,0) || RTLNX_RHEL_RANGE(9,9, 9,99)
++ /*
++ * Since Linux 6.19 the DRM core allocates the struct fb_info instance
++ * before it calls into this callback, and drm_fb_helper_alloc_info() is
++ * no longer available to drivers. A version check alone cannot express
++ * that, because the change was backported into the middle of the 6.6,
++ * 6.12 and 6.18 stable series, so let the build system tell us as well.
++ */
++#if RTLNX_VER_MIN(6,19,0) || RTLNX_RHEL_RANGE(9,9, 9,99) || defined(VBOX_NO_DRM_FB_HELPER_ALLOC_INFO)
+ info = helper->info;
+ #elif RTLNX_VER_MIN(6,2,0) || RTLNX_RHEL_RANGE(8,9, 8,99) || RTLNX_RHEL_RANGE(9,3, 9,99)
+ info = drm_fb_helper_alloc_info(helper);
diff --git a/meta-oe/recipes-support/vboxguestdrivers/vboxguestdrivers_7.2.14.bb b/meta-oe/recipes-support/vboxguestdrivers/vboxguestdrivers_7.2.14.bb
index 45f3f22481..952eca1a06 100644
--- a/meta-oe/recipes-support/vboxguestdrivers/vboxguestdrivers_7.2.14.bb
+++ b/meta-oe/recipes-support/vboxguestdrivers/vboxguestdrivers_7.2.14.bb
@@ -22,6 +22,7 @@ VBOX_NAME = "VirtualBox-${PV}"
SRC_URI = "http://download.virtualbox.org/virtualbox/${PV}/${VBOX_NAME}.tar.bz2 \
file://Makefile.utils \
+ file://0001-vboxvideo-let-the-build-decide-if-drm_fb_helper_alloc.patch \
"
SRC_URI[sha256sum] = "384f293184c52fd51bc941c17d753b4019446f53a6b07c828adfb3e61fe0a500"
@@ -32,7 +33,18 @@ S:task-patch = "${UNPACKDIR}/${BP}"
export VBOX_KBUILD_TARGET_ARCH = "${ARCH}"
export VBOX_KBUILD_TARGET_ARCH:x86-64 = "amd64"
-EXTRA_OEMAKE += "KERN_DIR='${WORKDIR}/${KERNEL_VERSION}/build' KERN_MAJ='${@(oe.kernel.get_version_file('${STAGING_KERNEL_BUILDDIR}') or '').split('.')[0]}' KBUILD_VERBOSE=1 CC='${CC} ${DEBUG_PREFIX_MAP} -ffile-prefix-map=${STAGING_KERNEL_DIR}=${KERNEL_SRC_PATH} -ffile-prefix-map=${STAGING_KERNEL_BUILDDIR}=${KERNEL_SRC_PATH}'"
+# The Makefile uses KERN_MAJ to decide whether vboxvideo is built. It defaults to
+# the *host* kernel version (uname -r), so pass the target one instead.
+KERN_MAJ = "${@(oe.kernel.get_version_file(d.getVar('STAGING_KERNEL_BUILDDIR')) or '').split('.')[0]}"
+
+# VirtualBox only ships the out-of-tree vboxvideo DRM module for kernels older
+# than 7.x - from 7.x on the in-tree drivers/gpu/drm/vboxvideo driver is used
+# instead. Mirror that decision so the compile check, the install step and the
+# packaging stay in sync with what "make all" actually produced.
+VBOX_VIDEO_MODULE = "${@'vboxvideo' if (d.getVar('KERN_MAJ') or '').isdigit() and int(d.getVar('KERN_MAJ')) < 7 else ''}"
+VBOX_MODULES = "vboxguest vboxsf ${VBOX_VIDEO_MODULE}"
+
+EXTRA_OEMAKE += "KERN_DIR='${WORKDIR}/${KERNEL_VERSION}/build' KERN_MAJ='${KERN_MAJ}' KBUILD_VERBOSE=1 CC='${CC} ${DEBUG_PREFIX_MAP} -ffile-prefix-map=${STAGING_KERNEL_DIR}=${KERNEL_SRC_PATH} -ffile-prefix-map=${STAGING_KERNEL_BUILDDIR}=${KERNEL_SRC_PATH}'"
# otherwise 5.2.22 builds just vboxguest
MAKE_TARGETS = "all"
@@ -70,20 +82,28 @@ do_configure:prepend() {
# compile and install mount utility
do_compile() {
- oe_runmake all
- oe_runmake 'LD=${CC}' 'EXTRA_CFLAGS=-I${STAGING_KERNEL_BUILDDIR}/include/' 'LDFLAGS=${LDFLAGS}' -C ${S}/utils
- if ! [ -e vboxguest.ko -a -e vboxsf.ko -a -e vboxvideo.ko ] ; then
- echo "ERROR: One of vbox*.ko modules wasn't built"
- exit 1
+ vbox_kcflags=""
+ if [ -e "${STAGING_KERNEL_DIR}/include/drm/drm_fb_helper.h" ] &&
+ ! grep -q drm_fb_helper_alloc_info "${STAGING_KERNEL_DIR}/include/drm/drm_fb_helper.h"; then
+ vbox_kcflags="-DVBOX_NO_DRM_FB_HELPER_ALLOC_INFO"
fi
+
+ oe_runmake all KCFLAGS="$vbox_kcflags"
+ oe_runmake 'LD=${CC}' 'EXTRA_CFLAGS=-I${STAGING_KERNEL_BUILDDIR}/include/' 'LDFLAGS=${LDFLAGS}' -C ${S}/utils
+ for m in ${VBOX_MODULES} ; do
+ if ! [ -e $m.ko ] ; then
+ echo "ERROR: kernel module $m.ko wasn't built"
+ exit 1
+ fi
+ done
}
module_do_install() {
MODULE_DIR=${D}${nonarch_base_libdir}/modules/${KERNEL_VERSION}/kernel/misc
install -d $MODULE_DIR
- install -m 644 vboxguest.ko $MODULE_DIR
- install -m 644 vboxsf.ko $MODULE_DIR
- install -m 644 vboxvideo.ko $MODULE_DIR
+ for m in ${VBOX_MODULES} ; do
+ install -m 644 $m.ko $MODULE_DIR
+ done
}
do_install:append() {
@@ -91,10 +111,11 @@ do_install:append() {
install -m 755 ${S}/utils/mount.vboxsf ${D}${base_sbindir}
}
-PACKAGES += "kernel-module-vboxguest kernel-module-vboxsf kernel-module-vboxvideo"
-RRECOMMENDS:${PN} += "kernel-module-vboxguest kernel-module-vboxsf kernel-module-vboxvideo"
+VBOX_MODULE_PACKAGES = "${@' '.join('kernel-module-' + m for m in d.getVar('VBOX_MODULES').split())}"
+PACKAGES += "${VBOX_MODULE_PACKAGES}"
+RRECOMMENDS:${PN} += "${VBOX_MODULE_PACKAGES}"
FILES:${PN} = "${base_sbindir}"
# autoload if installed
-KERNEL_MODULE_AUTOLOAD += "vboxguest vboxsf vboxvideo"
+KERNEL_MODULE_AUTOLOAD += "${VBOX_MODULES}"