recipes-kernel: add kpatch dynamic kernel patching infrastructure

kpatch is a Linux dynamic kernel patching infrastructure
which allows you to patch a running kernel without
rebooting or restarting any processes

Currently it is enabled and tested on x86-64 systems,
although can be extended to PPC64 as well.

Signed-off-by: Ruslan Bilovol <rbilovol@cisco.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

4 files changed, 225 insertions, 0 deletions

diff --git a/meta-oe/recipes-kernel/kpatch/kpatch.inc b/meta-oe/recipes-kernel/kpatch/kpatch.inc
new file mode 100644
index 000000000..b1e73e954
--- /dev/null
+++ b/meta-oe/recipes-kernel/kpatch/kpatch.inc
@@ -0,0 +1,49 @@
+SUMMARY = "Linux dynamic kernel patching infrastructure"
+DESCRIPTION = "kpatch is a Linux dynamic kernel patching infrastructure which allows you to patch a running kernel without rebooting or restarting any processes."
+LICENSE = "GPLv2 & LGPLv2"
+DEPENDS = "elfutils bash"
+
+SRC_URI = "git://github.com/dynup/kpatch.git;protocol=https \
+        file://0001-kpatch-build-add-cross-compilation-support.patch \
+        file://0002-kpatch-build-allow-overriding-of-distro-name.patch \
+        "
+
+EXTRA_OEMAKE = " \
+        PREFIX=${prefix} \
+        BINDIR=${D}${bindir} \
+        SBINDIR=${D}${sbindir} \
+        LIBDIR=${D}${libdir} \
+        MANDIR=${D}${mandir}/man1 \
+        SYSTEMDDIR=${D}${systemd_system_unitdir} \
+        DESTDIR=${D} \
+        BUILDMOD=no \
+        CC='${CC}' \
+        "
+
+S = "${WORKDIR}/git"
+
+do_install () {
+        oe_runmake install
+}
+
+PACKAGES =+ "kpatch-build"
+PROVIDES += "kpatch-build"
+
+COMPATIBLE_HOST = "(x86_64).*-linux"
+
+RDEPENDS_${PN} = "bash binutils"
+RDEPENDS_kpatch-build = "bash glibc-utils"
+
+FILES_${PN} = " \
+        ${sbindir}/kpatch \
+        ${systemd_system_unitdir}/kpatch.service \
+        ${mandir}/man1/kpatch.1.gz \
+        "
+FILES_kpatch-build = " \
+        ${bindir}/kpatch-build \
+        ${libexecdir}/* \
+        ${datadir}/kpatch \
+        ${mandir}/man1/kpatch-build.1.gz \
+        "
+
+SYSTEMD_SERVICE_${PN} = "kpatch.service"
diff --git a/meta-oe/recipes-kernel/kpatch/kpatch/0001-kpatch-build-add-cross-compilation-support.patch b/meta-oe/recipes-kernel/kpatch/kpatch/0001-kpatch-build-add-cross-compilation-support.patch
new file mode 100644
index 000000000..459fb2197
--- /dev/null
+++ b/meta-oe/recipes-kernel/kpatch/kpatch/0001-kpatch-build-add-cross-compilation-support.patch
@@ -0,0 +1,103 @@
+From a9a80a1f4df65892a0269295ce8a64b06f2ff61d Mon Sep 17 00:00:00 2001
+From: Ruslan Bilovol <rbilovol@cisco.com>
+Date: Tue, 19 Dec 2017 15:59:04 +0200
+Subject: [PATCH] kpatch-build: add cross-compilation support
+
+This patch introduces new option for kpatch-build
+script "--cross-compile" which can be used for
+specifying cross-complier prefix.
+It allows to build live patches not only on
+target system, but also on hosts for a target other
+than the one on which the compiler is running
+
+Also removed quotes in exec lines, so it is
+possible to pass multy-component strings like
+"ccache x86_64-xelinux-linux-" as cross-compiler
+
+Upstream-Status: Pending
+
+Signed-off-by: Ruslan Bilovol <rbilovol@cisco.com>
+---
+ kpatch-build/kpatch-build | 13 +++++++++++--
+ kpatch-build/kpatch-gcc   |  4 ++--
+ 2 files changed, 13 insertions(+), 4 deletions(-)
+
+diff --git a/kpatch-build/kpatch-build b/kpatch-build/kpatch-build
+index 166ecbd..af24cc4 100755
+--- a/kpatch-build/kpatch-build
++++ b/kpatch-build/kpatch-build
+@@ -195,7 +195,7 @@ gcc_version_check() {
+        # gcc --version varies between distributions therefore extract version
+        # by compiling a test file and compare it to vmlinux's version.
+        echo 'void main(void) {}' > "$c"
+-       out="$(gcc -c -pg -ffunction-sections -o "$o" "$c" 2>&1)"
++       out="$(${KPATCH_CROSS_COMPILE}gcc -c -pg -ffunction-sections -o "$o" "$c" 2>&1)"
+        gccver="$(gcc_version_from_file "$o")"
+        kgccver="$(gcc_version_from_file "$VMLINUX")"
+        rm -f "$c" "$o"
+@@ -381,12 +381,14 @@ usage() {
+        echo "          -d, --debug        Enable 'xtrace' and keep scratch files" >&2
+        echo "                             in <CACHEDIR>/tmp" >&2
+        echo "                             (can be specified multiple times)" >&2
++       echo "          --cross-compile    Specify the prefix used for all executables" >&2
++       echo "                             used during compilation" >&2
+        echo "          --skip-cleanup     Skip post-build cleanup" >&2
+        echo "          --skip-gcc-check   Skip gcc version matching check" >&2
+        echo "                             (not recommended)" >&2
+ }
+ 
+-options="$(getopt -o ha:r:s:c:v:j:t:n:o:d -l "help,archversion:,sourcerpm:,sourcedir:,config:,vmlinux:,jobs:,target:,name:,output:,debug,skip-gcc-check,skip-cleanup" -- "$@")" || die "getopt failed"
++options="$(getopt -o ha:r:s:c:v:j:t:n:o:d -l "help,archversion:,sourcerpm:,sourcedir:,config:,vmlinux:,jobs:,target:,name:,output:,debug,cross-compile:,skip-gcc-check,skip-cleanup" -- "$@")" || die "getopt failed"
+ 
+ eval set -- "$options"
+ 
+@@ -444,6 +446,10 @@ while [[ $# -gt 0 ]]; do
+                        echo "DEBUG mode enabled"
+                fi
+                ;;
++       --cross-compile)
++               KPATCH_CROSS_COMPILE="$2"
++               shift
++               ;;
+        --skip-cleanup)
+                echo "Skipping cleanup"
+                SKIPCLEANUP=1
+@@ -691,6 +697,8 @@ if [[ $DEBUG -ge 4 ]]; then
+        export KPATCH_GCC_DEBUG=1
+ fi
+ 
++export KPATCH_CROSS_COMPILE
++
+ echo "Building original kernel"
+ ./scripts/setlocalversion --save-scmversion || die
+ make mrproper 2>&1 | logger || die
+@@ -840,6 +848,7 @@ cd "$TEMPDIR/patch" || die
+ KPATCH_BUILD="$SRCDIR" KPATCH_NAME="$MODNAME" \
+ KBUILD_EXTRA_SYMBOLS="$KBUILD_EXTRA_SYMBOLS" \
+ KPATCH_LDFLAGS="$KPATCH_LDFLAGS" \
++CROSS_COMPILE="$KPATCH_CROSS_COMPILE" \
+        make 2>&1 | logger || die
+ 
+ if ! "$KPATCH_MODULE"; then
+diff --git a/kpatch-build/kpatch-gcc b/kpatch-build/kpatch-gcc
+index 6ba133c..3937948 100755
+--- a/kpatch-build/kpatch-gcc
++++ b/kpatch-build/kpatch-gcc
+@@ -8,7 +8,7 @@ TOOLCHAINCMD="$1"
+ shift
+ 
+ if [[ -z "$KPATCH_GCC_TEMPDIR" ]]; then
+-       exec "$TOOLCHAINCMD" "$@"
++       exec ${KPATCH_CROSS_COMPILE}${TOOLCHAINCMD} "$@"
+ fi
+ 
+ declare -a args=("$@")
+@@ -80,4 +80,4 @@ elif [[ "$TOOLCHAINCMD" = "ld" ]] ; then
+        done
+ fi
+ 
+-exec "$TOOLCHAINCMD" "${args[@]}"
++exec ${KPATCH_CROSS_COMPILE}${TOOLCHAINCMD} "${args[@]}"
+-- 
+1.9.1
+
diff --git a/meta-oe/recipes-kernel/kpatch/kpatch/0002-kpatch-build-allow-overriding-of-distro-name.patch b/meta-oe/recipes-kernel/kpatch/kpatch/0002-kpatch-build-allow-overriding-of-distro-name.patch
new file mode 100644
index 000000000..a9d8a7f2c
--- /dev/null
+++ b/meta-oe/recipes-kernel/kpatch/kpatch/0002-kpatch-build-allow-overriding-of-distro-name.patch
@@ -0,0 +1,62 @@
+From d418d716dae1e2a05131dfb42a19a4da2fc8a85d Mon Sep 17 00:00:00 2001
+From: Ruslan Bilovol <rbilovol@cisco.com>
+Date: Tue, 2 Jan 2018 14:50:03 +0200
+Subject: [PATCH] kpatch-build: allow overriding of distro name
+
+It is sometimes useful to have ability to override
+distro name, for example during cross-compilation
+build when livepatch modules will be ran on the
+target which differs from host.
+
+This patch adds a new --distro option which
+implements all needed functionality
+
+Upstream-Status: Pending
+
+Signed-off-by: Ruslan Bilovol <rbilovol@cisco.com>
+---
+ kpatch-build/kpatch-build | 9 +++++++--
+ 1 file changed, 7 insertions(+), 2 deletions(-)
+
+diff --git a/kpatch-build/kpatch-build b/kpatch-build/kpatch-build
+index af24cc4..4f9f78d 100755
+--- a/kpatch-build/kpatch-build
++++ b/kpatch-build/kpatch-build
+@@ -383,12 +383,13 @@ usage() {
+        echo "                             (can be specified multiple times)" >&2
+        echo "          --cross-compile    Specify the prefix used for all executables" >&2
+        echo "                             used during compilation" >&2
++       echo "          --distro           Override distro name" >&2
+        echo "          --skip-cleanup     Skip post-build cleanup" >&2
+        echo "          --skip-gcc-check   Skip gcc version matching check" >&2
+        echo "                             (not recommended)" >&2
+ }
+ 
+-options="$(getopt -o ha:r:s:c:v:j:t:n:o:d -l "help,archversion:,sourcerpm:,sourcedir:,config:,vmlinux:,jobs:,target:,name:,output:,debug,cross-compile:,skip-gcc-check,skip-cleanup" -- "$@")" || die "getopt failed"
++options="$(getopt -o ha:r:s:c:v:j:t:n:o:d -l "help,archversion:,sourcerpm:,sourcedir:,config:,vmlinux:,jobs:,target:,name:,output:,debug,cross-compile:,distro:,skip-gcc-check,skip-cleanup" -- "$@")" || die "getopt failed"
+ 
+ eval set -- "$options"
+ 
+@@ -450,6 +451,10 @@ while [[ $# -gt 0 ]]; do
+                KPATCH_CROSS_COMPILE="$2"
+                shift
+                ;;
++       --distro)
++               DISTRO="$2"
++               shift
++               ;;
+        --skip-cleanup)
+                echo "Skipping cleanup"
+                SKIPCLEANUP=1
+@@ -526,7 +531,7 @@ fi
+ # Don't check external file.
+ # shellcheck disable=SC1091
+ source /etc/os-release
+-DISTRO="$ID"
++DISTRO="${DISTRO:-${ID}}"
+ if [[ "$DISTRO" = fedora ]] || [[ "$DISTRO" = rhel ]] || [[ "$DISTRO" = ol ]] || [[ "$DISTRO" = centos ]]; then
+        [[ -z "$VMLINUX" ]] && VMLINUX="/usr/lib/debug/lib/modules/$ARCHVERSION/vmlinux"
+        [[ -e "$VMLINUX" ]] || die "kernel-debuginfo-$ARCHVERSION not installed"
+-- 
+1.9.1
+
diff --git a/meta-oe/recipes-kernel/kpatch/kpatch_git.bb b/meta-oe/recipes-kernel/kpatch/kpatch_git.bb
new file mode 100644
index 000000000..e495e2882
--- /dev/null
+++ b/meta-oe/recipes-kernel/kpatch/kpatch_git.bb
@@ -0,0 +1,11 @@
+require kpatch.inc
+
+LIC_FILES_CHKSUM = "file://COPYING;md5=b234ee4d69f5fce4486a80fdaf4a4263"
+
+SRCREV = "db6efbb8c7e90d2b761272cf563047119072768f"
+
+PV = "0.5.0+git${SRCPV}"
+
+S = "${WORKDIR}/git"
+
+BBCLASSEXTEND = "native nativesdk"