support to build an rhel8 kernel

Use:
docker build -f dockerfiles/kernel-images-rhel8 .

Requres: cilium/little-vm-helper#144

Signed-off-by: Lorenz Bauer <[email protected]>
Signed-off-by: Kornilios Kourtis <[email protected]>

_data/kernels.json

@@ -27,6 +27,16 @@
         {
             "name": "4.19",
             "url": "git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git?depth=1#linux-4.19.y"
+        },
+        {
+            "name": "rhel8",
+            "opts": [
+                 [ "--enable",  "CONFIG_EXT4_FS"],
+                 [ "--disable", "CONFIG_SECURITY_APPARMOR"],
+                 [ "--disable", "CONFIG_NF_CONNTRACK"],
+                 [ "--disable", "CONFIG_MODULE_SIG"],
+                 [ "--disable", "CONFIG_MODULE_SIG_ALL"]
+             ]
         }
     ],
     "common_opts": [

dockerfiles/kernel-images-rhel8

@@ -0,0 +1,49 @@
+# syntax=docker/dockerfile:1.3-labs
+# vim: set ft=dockerfile:
+
+FROM quay.io/lvh-images/lvh:latest AS lvh
+
+FROM rockylinux:8 AS builder
+
+COPY --from=lvh /usr/bin/lvh /usr/bin/lvh
+
+RUN dnf install -y 'dnf-command(builddep)' 'dnf-command(config-manager)'
+RUN dnf config-manager --set-enabled powertools
+RUN dnf builddep -y kernel
+
+FROM builder AS prepare
+
+WORKDIR /tmp
+RUN dnf download --source kernel && rpm -ivh kernel*.src.rpm
+
+WORKDIR /root/rpmbuild/SPECS
+RUN rpmbuild -bp kernel.spec --with baseonly
+
+RUN ln -s /root/rpmbuild/BUILD/kernel-*/linux-* /tmp/build
+WORKDIR /tmp/build
+
+RUN mkdir patches
+COPY patches/rhel8/*.patch patches/
+RUN for p in patches/*.patch; do echo "Applying $p"; patch -p1 < "$p" || exit 1; done
+
+# Emulate InitBuildVars() from kernel.spec
+RUN make -s mrproper
+RUN cp configs/kernel-*-$(uname -m)-debug.config .config
+
+# Remove all RHEL modules
+RUN sed --in-place -E -e 's/^(CONFIG_[^=]+)=m/# \1 is not set/' .config
+
+COPY _data /data
+
+RUN lvh kernels --dir /data raw_configure . rhel8 2>&1
+
+FROM prepare AS build
+
+RUN make -j $(nproc)
+RUN make tar-pkg
+
+COPY scripts/generate-btf.sh /tmp/
+RUN /tmp/generate-btf.sh /tmp/build/tar-install
+
+FROM busybox as kernel
+COPY --from=build /tmp/build/tar-install /data/kernels/rhel8

patches/rhel8/0001-fs-9p-vfs_file.c-use-new-return-type-vm_fault_t.patch

@@ -0,0 +1,38 @@
+From fe6340e2d1f5ef9ebb9a82665b053c362837cbd6 Mon Sep 17 00:00:00 2001
+From: Souptick Joarder <[email protected]>
+Date: Tue, 17 Jul 2018 19:14:35 -0700
+Subject: [PATCH] fs/9p/vfs_file.c: use new return type vm_fault_t
+
+Use new return type vm_fault_t for page_mkwrite handler.
+
+See 1c8f422059ae ("mm: change return type to vm_fault_t") for reference.
+
+Link: http://lkml.kernel.org/r/20180702154928.GA3964@jordon-HP-15-Notebook-PC
+Signed-off-by: Souptick Joarder <[email protected]>
+Reviewed-by: Matthew Wilcox <[email protected]>
+Acked-by: Jun Piao <[email protected]>
+Cc: Eric Van Hensbergen <[email protected]>
+Cc: Ron Minnich <[email protected]>
+Cc: Latchesar Ionkov <[email protected]>
+Signed-off-by: Andrew Morton <[email protected]>
+Signed-off-by: Dominique Martinet <[email protected]>
+---
+ fs/9p/vfs_file.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
+index 03c9e325bfbc..5f2e48d41d72 100644
+--- a/fs/9p/vfs_file.c
++++ b/fs/9p/vfs_file.c
+@@ -533,7 +533,7 @@ v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
+ 	return retval;
+ }
+
+-static int
++static vm_fault_t
+ v9fs_vm_page_mkwrite(struct vm_fault *vmf)
+ {
+ 	struct v9fs_inode *v9inode;
+-- 
+2.43.0
+