kernel: Add support for the 4.19 kernel

The kernel configs were constructed by running the 4.18.x config
through the 4.19 oldconfig process.

The 4.19.x has a new option, RANDOM_TRUST_CPU, which indicates
if the CPUs random instruction is to be trusted. It defaults to
"no" and this default was accepted.

Most of the defaults were accepted, except for:
BLK_CGROUP_IOLATENCY=y
NFT_TUNNEL=y
NFT_OSF=y
NFT_TPROXY=y
NETFILTER_XT_MATCH_SOCKET=y
NET_VENDOR_CADENCE=n
NET_VENDOR_NETERION=n
NET_VENDOR_PACKET_ENGINES=n

We also disallow CIFS for insecure legacy servers:
CIFS_ALLOW_INSECURE_LEGACY=n

For arm64, the following changes were made to the default:
SENSORS_RASPBERRYPI_HWMON=y
CRYPTO_DEV_QCOM_RNG=m
CRYPTO_DEV_HISI_SEC=m

For s390x, the additional changes were made to the default:
KERNEL_BZIP2 (default is gzip)
GCC_PLUGINS=y
GCC_PLUGIN_STRUCTLEAK=y
GCC_PLUGIN_STRUCTLEAK_BYREF_ALL=y
GCC_PLUGIN_RANDSTRUCT=y
GCC_PLUGIN_RANDSTRUCT_PERFORMANCE=y

Running the 4.18 and 4.19 kernel config through
./scripts/kconfig-split.py yields the following 4.19.x
only config options for x86_64:

The x86_64 kernel difference to 4.18 for

CONFIG_ARCH_SUPPORTS_ACPI=y
CONFIG_BLK_CGROUP_IOLATENCY=y
CONFIG_BNXT_HWMON=y
CONFIG_BUILD_SALT=""
CONFIG_CONSOLE_LOGLEVEL_QUIET=4
CONFIG_CRASH_CORE=y
CONFIG_HAVE_ARCH_PREL32_RELOCATIONS=y
CONFIG_HAVE_RELIABLE_STACKTRACE=y
CONFIG_MEMCG_KMEM=y
CONFIG_MLX5_EN_ARFS=y
CONFIG_MLX5_EN_RXNFC=y
CONFIG_NETFILTER_NETLINK_OSF=y
CONFIG_NETFILTER_XT_MATCH_SOCKET=y
CONFIG_NFT_OSF=y
CONFIG_NFT_TPROXY=y
CONFIG_NFT_TUNNEL=y
CONFIG_NF_SOCKET_IPV4=y
CONFIG_NF_SOCKET_IPV6=y
CONFIG_XEN_SCRUB_PAGES_DEFAULT=y

Signed-off-by: Rolf Neugebauer <rn@rneugeba.io>

kernel/Makefile

@@ -259,6 +259,7 @@ endef
 # Debug targets only for latest stable and LTS stable
 #
 ifeq ($(ARCH),x86_64)
+$(eval $(call kernel,4.19,4.19.x,$(EXTRA),$(DEBUG)))
 $(eval $(call kernel,4.18.16,4.18.x,$(EXTRA),$(DEBUG)))
 $(eval $(call kernel,4.14.78,4.14.x,$(EXTRA),$(DEBUG)))
 $(eval $(call kernel,4.14.78,4.14.x,,-dbg))
@@ -267,11 +268,13 @@ $(eval $(call kernel,4.9.135,4.9.x,$(EXTRA),$(DEBUG)))
 $(eval $(call kernel,4.4.162,4.4.x,$(EXTRA),$(DEBUG)))
 
 else ifeq ($(ARCH),aarch64)
+$(eval $(call kernel,4.19,4.19.x,$(EXTRA),$(DEBUG)))
 $(eval $(call kernel,4.18.16,4.18.x,$(EXTRA),$(DEBUG)))
 $(eval $(call kernel,4.14.78,4.14.x,$(EXTRA),$(DEBUG)))
 $(eval $(call kernel,4.14.71,4.14.x,-rt,))
 
 else ifeq ($(ARCH),s390x)
+$(eval $(call kernel,4.19,4.19.x,$(EXTRA),$(DEBUG)))
 $(eval $(call kernel,4.18.16,4.18.x,$(EXTRA),$(DEBUG)))
 $(eval $(call kernel,4.14.78,4.14.x,$(EXTRA),$(DEBUG)))
 endif