X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;ds=sidebyside;f=scripts%2Flttng-modules%2Fparam-build.sh;h=fd13877184758d43f835bc0fc8c21c678ec72c7f;hb=ad23f63b8f220bce0eda8769ca18d84fd6c57530;hp=7f965b47b712a2ea9b2f46648cd44e217e36d6cb;hpb=5a1968040cbe0ce9024228933a7a6e5fac0d7295;p=lttng-ci.git

diff --git a/scripts/lttng-modules/param-build.sh b/scripts/lttng-modules/param-build.sh
index 7f965b4..fd13877 100644
--- a/scripts/lttng-modules/param-build.sh
+++ b/scripts/lttng-modules/param-build.sh
@@ -1,6 +1,6 @@
-#!/bin/bash -exu
+#!/bin/bash
 #
-# Copyright (C) 2016-2018 - Michael Jeanson <mjeanson@efficios.com>
+# Copyright (C) 2016-2019 Michael Jeanson <mjeanson@efficios.com>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -15,14 +15,29 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+set -exu
+
 # Parameters
-arch=${arch:-}
+platforms=${platforms:-}
+# Derive arch from label if it isn't set
+if [ -z "${arch:-}" ] ; then
+    # Labels may be platform specific, eg. jammy-amd64, deb12-armhf
+    regex='[[:alnum:]]+-([[:alnum:]]+)'
+    if [[ "${platforms}" =~ ${regex} ]] ; then
+        arch="${BASH_REMATCH[1]}"
+    else
+        arch="${platforms:-}"
+    fi
+fi
+
 cross_arch=${cross_arch:-}
 ktag=${ktag:-}
 kgitrepo=${kgitrepo:-}
 mversion=${mversion:-}
 mgitrepo=${mgitrepo:-}
+make_args=()
 
+DEBUG=${DEBUG:-}
 
 ## FUNCTIONS ##
 
@@ -32,6 +47,7 @@ verlte() {
 }
 
 verlt() {
+    # shellcheck disable=SC2015
     [ "$1" = "$2" ] && return 1 || verlte "$1" "$2"
 }
 
@@ -40,13 +56,21 @@ vergte() {
 }
 
 vergt() {
+    # shellcheck disable=SC2015
     [ "$1" = "$2" ] && return 1 || vergte "$1" "$2"
 }
 
-
 git_clone_modules_sources() {
     mkdir -p "$MODULES_GIT_DIR"
-    git clone --depth=1 -b "${mversion}" "${mgitrepo}" "$MODULES_GIT_DIR"
+
+    # If the version starts with "refs/", checkout the specific git ref, otherwise treat it
+    # as a branch name.
+    if [ "${mversion:0:5}" = "refs/" ]; then
+        git clone --no-tags --depth=1 "${mgitrepo}" "$MODULES_GIT_DIR"
+        (cd "$MODULES_GIT_DIR" && git fetch origin "${mversion}" && git checkout FETCH_HEAD)
+    else
+        git clone --no-tags --depth=1 -b "${mversion}" "${mgitrepo}" "$MODULES_GIT_DIR"
+    fi
 }
 
 # Checkout a shallow kernel tree of the specified tag
@@ -71,7 +95,7 @@ upload_archive_obj() {
 
 
 extract_archive_obj() {
-    tar -xf "$WORKSPACE/$obj_name" -C "$LINUX_OBJ_DIR"
+    tar -xf "$WORKSPACE/$obj_name" -C "$LINUX_OBJ_DIR" -I pbzip2
     rm -f "$WORKSPACE/$obj_name"
 }
 
@@ -82,6 +106,16 @@ tar_archive_obj() {
     cd -
 }
 
+list_gccs() {
+    local gccs
+    gccs=()
+    IFS=: read -r -a path_array <<< "$PATH"
+    while read -r gcc ; do
+        gccs+=("$gcc")
+    done < <(find "${path_array[@]}" -maxdepth 1 -regex '.*/gcc-[0-9\.]+$' -printf '%f\n' | sort -t- -k2 -V -r)
+    echo "${gccs[@]}"
+}
+
 # Find the most recent GCC version supported by the kernel sources
 select_compiler() {
     local selected_cc
@@ -92,8 +126,17 @@ select_compiler() {
 
     set +e
 
-    for cc in gcc-7 gcc-5 gcc-4.9; do
-      if "${CROSS_COMPILE:-}${cc}" -I include/ -D__LINUX_COMPILER_H -D__LINUX_COMPILER_TYPES_H -E include/linux/compiler-gcc.h; then
+    for cc in $(list_gccs) ; do
+        if "${CROSS_COMPILE:-}${cc}" -I include/ -D__LINUX_COMPILER_H -D__LINUX_COMPILER_TYPES_H -E include/linux/compiler-gcc.h; then
+            cc_version=$(echo "${cc}" | cut -d'-' -f2)
+            if { verlt "${kversion}" "5.17"; } && { vergt "${cc_version}" "11"; } ; then
+                # Using gcc-12+ with '-Wuse-after-free' breaks the build of older
+                # kernels (in particular, objtool). Some releases on LTS
+                # branches between 4.x and 5.15 can be built with gcc-12.
+                # @see https://lore.kernel.org/lkml/20494.1643237814@turing-police/
+                # @see https://gitlab.com/linux-kernel/stable/-/commit/52a9dab6d892763b2a8334a568bd4e2c1a6fde66
+                continue
+            fi
         selected_cc="$cc"
         break
       fi
@@ -101,36 +144,107 @@ select_compiler() {
 
     set -e
 
+    # Force gcc-4.8 for kernels before 4.4
+    if { verlt "$kversion" "4.4"; }; then
+        selected_cc='gcc-4.8'
+    fi
+
     if [ "x$selected_cc" = "x" ]; then
       echo "Found no suitable compiler."
       exit 1
     fi
 
-    # Force gcc-4 for buggy kernel branches
-    if { vergte "$kversion" "3.2" && verlt "$kversion" "3.3"; } || \
-       { vergte "$kversion" "3.4" && verlt "$kversion" "3.5"; } || \
-       { vergte "$kversion" "3.17" && verlt "$kversion" "3.18"; }; then
-      selected_cc=gcc-4.9
+    _KAFLAGS=()
+    _KCFLAGS=()
+    _KCPPFLAGS=()
+    _HOSTCFLAGS=()
+    if [ "$selected_cc" != "gcc-4.8" ]; then
+        # Older kernel Makefiles do not expect the compiler to default to PIE
+        _KAFLAGS+=(-fno-pie)
+        _KCFLAGS+=(
+            -fno-pie
+            -no-pie
+            -fno-stack-protector
+        )
+        _KCPPFLAGS+=(-fno-pie)
     fi
 
-    case "$ktag" in
-      Ubuntu*)
-        if { vergte "$kversion" "3.13" && verlt "$kversion" "3.14"; }; then
-          selected_cc=gcc-4.9
+    selected_cc_version="$(echo "${selected_cc}" | cut -d'-' -f2)"
+    if { vergte "${selected_cc_version}" "10"; } && { verlt "${kversion}" "5.10"; } ; then
+        # gcc-10 changed the default from '-fcommon' to '-fno-common', which
+        # causes a linker failure. '-fcommon' can be set on the HOSTCFLAGS
+        # to avoid the issue.
+        # @see https://gitlab.com/linux-kernel/stable/-/commit/e33a814e772cdc36436c8c188d8c42d019fda639
+        _HOSTCFLAGS+=(-fcommon)
+    fi
+
+    if [ "${cross_arch:-}" == "armhf" ] ; then
+        if { verlt "${kversion}" "5.14"; } ; then
+            # Work-around for producing instructions that aren't valid for the
+            # default architectures.
+            # Eg. Error: selected processor does not support `cpsid i' in ARM mode
+            _KCFLAGS+=(-march=armv7-a -mfpu=vfpv3-d16)
+            _KCPPFLAGS+=(-march=armv7-a -mfpu=vfpv3-d16)
         fi
-      ;;
-    esac
+    fi
 
-    export CC="${CROSS_COMPILE:-}${selected_cc}"
+    if { vergt "${selected_cc_version}" "8"; } && { vergte "${kversion}" "4.15"; } && { verlt "${kversion}" "4.17"; } ; then
+        # This was added to -Wall in gcc 9 but some kernels do not include the fixes
+        # @see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88583
+        _KCFLAGS+=(-Wno-error=packed-not-aligned)
+    fi
 
+    export KAFLAGS="${_KAFLAGS[*]}"
+    export KCFLAGS="${_KCFLAGS[*]}"
+    export KCPPFLAGS="${_KCPPFLAGS[*]}"
+    export HOSTCFLAGS="${_HOSTCFLAGS[*]}"
+    export CC="${CROSS_COMPILE:-}${selected_cc}"
+    export HOSTCC="${selected_cc}"
+
+    make_args=(
+        CC="${CC}"
+        HOSTCC="${HOSTCC}"
+        HOSTCFLAGS="${HOSTCFLAGS:-}"
+    )
+    if [ -n "${DEBUG}" ] ; then
+        make_args+=(
+            V=1
+        )
+    fi
     cd -
 }
 
+patch_linux_kernel() {
+    local commit_hash
+    commit_hash="$1"
+    set +e
+    git -C "${LINUX_GIT_REF_REPO_DIR}" format-patch -n1 --stdout "${commit_hash}" | patch -p1
+    set -e
+    if [ "$?" -gt 1 ] ; then
+        echo "Serious issue patching"
+        exit 1
+    fi
+}
 
 build_linux_kernel() {
     cd "$LINUX_SRCOBJ_DIR"
 
-    kversion=$(make -s kernelversion)
+    kversion=$(make -s kernelversion "${make_args[@]}")
+    pahole_version="$(pahole --version | tr -d 'v')"
+
+    if { verlt "${kversion}" "3.3"; } && [ "${vanilla_config}" = "imx_v6_v7_defconfig" ] ; then
+        # imx_v6_v7 didn't exist before 06965c39b4c63933fa0a1cde2237ef85477c5655
+        if { verlt "${kversion}" "3.2"; } ; then
+            vanilla_config='mx5_defconfig'
+        else
+            vanilla_config='mx51_defconfig'
+        fi
+    fi
+
+    if { verlt "${kversion}" "3.13"; } && [ "${vanilla_config}" = "pseries_le_defconfig" ] ; then
+        # pseries_le_deconfig was introduced in f53e462e907cbaed29c49c0f10f5b8f614e1bf1d
+        vanilla_config='pseries_defconfig'
+    fi
 
     # Generate kernel configuration
     case "$ktag" in
@@ -141,30 +255,53 @@ build_linux_kernel() {
             exit 0
           fi
         fi
-        fakeroot debian/rules clean
-        fakeroot debian/rules genconfigs
+
+        # Disable riscv64 config generation, we don't have a toolchain on bionic
+        sed -i 's/riscv64 //' debian.master/etc/kernelconfig
+
+        fakeroot debian/rules clean KW_DEFCONFIG_DIR=.
+
+        # Hack for kernel Ubuntu-hwe-5.8
+        # The debian/control file is produced by the clean target above, so this
+        # check needs to happen afterwards.
+        if [ ! -f "debian/compat" ] && ! grep -q debhelper-compat debian/control; then
+            echo "10" > "debian/compat"
+        fi
+
+        # genconfigs check can fail in certain cases, eg. when a more recent
+        # compiler exposes kernel configuration flags which aren't set in the
+        # Ubuntu annotations.
+        # In any case, the configuration will be updated with any missing values
+        # later in our build script.
+        fakeroot debian/rules genconfigs KW_DEFCONFIG_DIR=. do_skip_checks=true
         cp CONFIGS/"${ubuntu_config}" .config
         ;;
+
       *)
-        # Force 32bit build on x86-32, default is 64bit
-        if [ "$arch" = "x86-32" ]; then
+        # Force 32bit build on i386, default is 64bit
+        if [ "$arch" = "i386" ]; then
             export ARCH="i386"
         fi
 
-        # allyesconfig is mostly broken for kernels of the 2.6 series
-        if verlt "$kversion" "3.0"; then
-            vanilla_config="defconfig"
-        fi
-
-        make "${vanilla_config}"
+        make "${vanilla_config}" "${make_args[@]}"
         ;;
     esac
 
-    # silentoldconfig was renamed in 4.19
+    if [ "${vanilla_config}" = "pseries_defconfig" ] && [ "${cross_arch}" = "ppc64el" ] ; then
+        # @see diff <(git show v3.13:arch/powerpc/configs/pseries_defconfig) <(git show v3.13:arch/powerpc/configs/pseries_le_defconfig)
+        scripts/config --enable CONFIG_CPU_LITTLE_ENDIAN
+        scripts/config --enable CONFIG_CMA
+        scripts/config --disable CONFIG_XMON_DEFAULT
+        # scripts/config --disable CONFIG_VIRTUALIZATION
+        # scripts/config --disable CONFIG_KVM_BOOK3S_64
+        scripts/config --disable CONFIG_KVM_BOOK3S_64_HV
+    fi
+
+    # oldnoconfig was renamed in 4.19
     if vergte "$kversion" "4.19"; then
-        update_conf_target="syncconfig"
+        update_conf_target="olddefconfig"
     else
-        update_conf_target="silentoldconfig"
+        update_conf_target="oldnoconfig"
     fi
 
     # Fix 'defined(@array)' was removed from recent perl
@@ -173,7 +310,7 @@ build_linux_kernel() {
     fi
 
     # Fix syntax of inline assembly which is confused with C++11 raw strings on gcc >= 5
-    if [ "$CC" != "gcc-4.9" ]; then
+    if [ "$HOSTCC" != "gcc-4.8" ]; then
       if [ -f "arch/x86/kvm/svm.c" ]; then
         sed -i 's/ R"/ R "/g; s/"R"/" R "/g' arch/x86/kvm/svm.c
       fi
@@ -183,11 +320,151 @@ build_linux_kernel() {
       fi
     fi
 
+    if { verlt "${kversion}" "5.11"; } && { vergte "${kversion}" "4.10"; } ; then
+        # Binutils > 2.35 strips empty symbol tables, causing obltool to fail
+        # in certain cases when files are empty.
+        # @see https://gitlab.com/linux-kernel/stable/-/commit/1d489151e9f9d1647110277ff77282fe4d96d09b
+        #
+        # There doesn't seem to be any LD/AS/AR flags to control this behaviour,
+        # therefore patching tools/objtool/elf.c is attempted.
+        patch_linux_kernel 1d489151e9f9d1647110277ff77282fe4d96d09b
+        if { verlt "${kversion}" "4.18"; } ; then
+            patch_linux_kernel e81e0724432542af8d8c702c31e9d82f57b1ff31
+        fi
+    fi
+
+    if { vergt "${selected_cc_version}" "7"; } && { vergte "${kversion}" "4.15"; } && { verlt "${kversion}" "4.17"; } ; then
+        # Builds fail due to -Werror=restrict in pager.o and str_error_r.o
+        if { verlt "${kversion}" "4.16"; } ; then
+            # This is patched since objtool's Makefile doesn't respect HOSTCFLAGS
+            # @see https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ad343a98e74e85aa91d844310e797f96fee6983b
+            patch_linux_kernel ad343a98e74e85aa91d844310e797f96fee6983b
+        fi
+        if { verlt "${kversion}" "4.17"; } ; then
+            # This is patched since objtool's Makefile doesn't respect HOSTCFLAGS
+            # @see https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=854e55ad289ef8888e7991f0ada85d5846f5afb9
+            patch_linux_kernel 854e55ad289ef8888e7991f0ada85d5846f5afb9
+        fi
+
+    fi
+
+    if { vergt "${selected_cc_version}" "9"; } && { verlt "${kversion}" "5.6"; } ; then
+        # Duplicate decalarations of __force_order
+        # @see https://gitlab.com/linux-kernel/stable/-/commit/df6d4f9db79c1a5d6f48b59db35ccd1e9ff9adfc
+        patch_linux_kernel df6d4f9db79c1a5d6f48b59db35ccd1e9ff9adfc
+        # However, kaslr_64.c doesn't exit in 4.15, 4.16, it's named pagetable.c
+        if [ -f arch/x86/boot/compressed/pagetable.c ] ; then
+            sed -i '/^unsigned long __force_order;$/d' arch/x86/boot/compressed/pagetable.c
+        fi
+    fi
+
+    if { vergte "${kversion}" "4.15"; } && { verlt "${kversion}" "4.18"; } ; then
+        # Some old kernels fail to build when make is too new
+        # @see https://gitlab.com/linux-kernel/stable/-/commit/9feeb638cde083c737e295c0547f1b4f28e99583
+        patch_linux_kernel 9564a8cf422d7b58f6e857e3546d346fa970191e
+        # @see https://gitlab.com/linux-kernel/stable/-/commit/9feeb638cde083c737e295c0547f1b4f28e99583
+        patch_linux_kernel 9feeb638cde083c737e295c0547f1b4f28e99583
+    fi
+
+    if { vergte "${kversion}" "4.12"; } && { verlt "${kversion}" "4.19"; } ; then
+        # Old kernels can fail to build while on newer host kernels with errors
+        # such as:
+        #   In file included from scripts/selinux/genheaders/genheaders.c:19:
+        #   ./security/selinux/include/classmap.h:249:2: error: #error New address family defined, please update secclass_map.
+        # @see https://gitlab.com/linux-kernel/stable/-/commit/dfbd199a7cfe3e3cd8531e1353cdbd7175bfbc5e
+        #
+        patch_linux_kernel dfbd199a7cfe3e3cd8531e1353cdbd7175bfbc5e
+    fi
+
+    if { vergte "${kversion}" "3.18"; } && { verlt "${kversion}" "4.4"; } ; then
+        # Compatibility with binutils >= ~ 2.31
+        patch_linux_kernel b21ebf2fb4cde1618915a97cc773e287ff49173e
+    fi
+
+    # The above patch only partially applies linux 3.17, and has been, so a
+    # rebased version is used instead.
+    if { vergte "${kversion}" "3.17"; } && { verlt "${kversion}" "3.18"; } ; then
+        cat <<'EOF' | patch -p1
+diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
+index 48598105..0652c5b6 100644
+--- a/arch/x86/kernel/machine_kexec_64.c
++++ b/arch/x86/kernel/machine_kexec_64.c
+@@ -516,6 +516,7 @@ int arch_kexec_apply_relocations_add(const Elf64_Ehdr *ehdr,
+ 				goto overflow;
+ 			break;
+ 		case R_X86_64_PC32:
++		case R_X86_64_PLT32:
+ 			value -= (u64)address;
+ 			*(u32 *)location = value;
+ 			break;
+diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
+index e69f9882..7c6bc9fe 100644
+--- a/arch/x86/kernel/module.c
++++ b/arch/x86/kernel/module.c
+@@ -180,6 +180,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
+ 				goto overflow;
+ 			break;
+ 		case R_X86_64_PC32:
++		case R_X86_64_PLT32:
+ 			val -= (u64)loc;
+ 			*(u32 *)loc = val;
+ #if 0
+diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
+index bbb1d225..8deeacbc 100644
+--- a/arch/x86/tools/relocs.c
++++ b/arch/x86/tools/relocs.c
+@@ -763,6 +763,7 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
+ 	switch (r_type) {
+ 	case R_X86_64_NONE:
+ 	case R_X86_64_PC32:
++	case R_X86_64_PLT32:
+ 		/*
+ 		 * NONE can be ignored and PC relative relocations don't
+ 		 * need to be adjusted.
+EOF
+    fi
+
+    if ( { vergte "${kversion}" "3.15"; } && { verlt "${kversion}" "4.4"; } ) ||
+       ( { vergte "${kversion}" "4.15"; } && { verlt "${kversion}" "4.17"; } ); then
+        # While the original motivation of this patch is for fixing builds using
+        # clang, the same error occurs between linux >= 3.15 and < 4.4, and in
+        # 4.15, 4.16.
+        #
+        # This patch only partially applies due to changes in kernel/Makefile,
+        # so a supplementary patch is needed
+        #
+        # Without this patch, builds fail with
+        #   Cannot find symbol for section 2: .text.
+        #   kernel/elfcore.o: failed
+        #
+        # @see https://github.com/linuxppc/issues/issues/388
+        # @see https://lore.kernel.org/lkml/20201204165742.3815221-2-arnd@kernel.org/
+        #
+        patch_linux_kernel 6e7b64b9dd6d96537d816ea07ec26b7dedd397b9
+        if grep -q elfcore.o kernel/Makefile ; then
+            sed -i '/^.* += elfcore.o$/d' kernel/Makefile
+        fi
+    fi
+
+    # Newer binutils don't accept 3 operand 'cmp' instructions on ppc64
+    # Convert them to 'cmpw' which was previously done silently
+    if verlt "$kversion" "4.9"; then
+	    find arch/powerpc/ -name "*.S" -print0 | xargs -0 sed -i "s/\(cmp\)\(\s\+[a-zA-Z0-9]\+,\s*[a-zA-Z0-9]\+,\s*[a-zA-Z0-9]\+\)/cmpw\2/"
+	    find arch/powerpc/ -name "*.S" -print0 | xargs -0 sed -i "s/\(cmpli\)\(\s\+[a-zA-Z0-9]\+,\s*[a-zA-Z0-9]\+,\s*[a-zA-Z0-9]\+\)/cmplwi\2/"
+	    sed -i "s/\$pie \-o \"\$ofile\"/\$pie --no-dynamic-linker -o \"\$ofile\"/" arch/powerpc/boot/wrapper
+    fi
+
     # Fix a typo in v2.6.36.x
     if [ -f "arch/x86/kernel/entry_64.S" ]; then
       sed -i 's/END(do_hypervisor_callback)/END(xen_do_hypervisor_callback)/' arch/x86/kernel/entry_64.S
     fi
 
+    # Fix compiler switch in vdso Makefile for 2.6.36 to 2.6.36.2
+    if { vergte "$kversion" "2.6.36" && verlte "$kversion" "2.6.36.3"; }; then
+      sed -i 's/-m elf_x86_64/-m64/' arch/x86/vdso/Makefile
+      sed -i 's/-m elf_i386/-m32/' arch/x86/vdso/Makefile
+    fi
+
     # Fix kernel < 3.0 with gcc >= 4.7
     if verlt "$kversion" "3.0"; then
       sed -i '/linux\/compiler.h/a #include <linux\/linkage.h> \/* For asmregparm *\/' arch/x86/include/asm/ptrace.h
@@ -196,44 +473,127 @@ build_linux_kernel() {
       echo "header-y += linkage.h" >> include/linux/Kbuild
     fi
 
+    if [ "${cross_arch}" = "powerpc" ] ; then
+        if { vergte "${kversion}" "4.15"; } && { verlt "${kversion}" "4.16"; } ; then
+            # Avoid register errors such as
+            # aes_generic.c:(.text+0x4e0): undefined reference to `_restgpr_31_x'
+            # @see https://gitlab.com/linux-kernel/stable/-/commit/148b974deea927f5dbb6c468af2707b488bfa2de
+            make_args+=(
+                CFLAGS_aes_generic.o=''
+            )
+        fi
+    fi
+
+    if [ "$(scripts/config --state CONFIG_DEBUG_INFO_BTF)" == "y" ] &&
+           { vergte "${pahole_version}" "1.24"; } &&
+           { vergte "${kversion}" "5.10"; } && { verlt "${kversion}" "6.0"; } ;then
+        # Some kernels Eg. Ubuntu-hwe-5.13-5.13.0-52.59_20.04.1
+        # fail with the following error:
+        #   BTFIDS  vmlinux
+        #   FAILED: load BTF from vmlinux: Invalid argument
+        #
+        # When CONFIG_DEBUG_INFO_BTF is set, certain versions of pahole require
+        # `--skip_encoding_btf_enum64` to be passed as the kernel doesn't define
+        # BTF_KIND_ENUM64.
+        #
+        # Introduced in 341dfcf8d78eaa3a2dc96dea06f0392eb2978364 (~v5.10)
+        # @see https://lore.kernel.org/bpf/20220825171620.cioobudss6ovyrkc@altlinux.org/t/
+        #
+        if [ -f "scripts/pahole-flags.sh" ] ; then
+            sed -i 's/ -J ${PAHOLE_FLAGS} / -J ${PAHOLE_FLAGS} --skip_encoding_btf_enum64 /' scripts/link-vmlinux.sh
+        else
+            sed -i 's/ -J ${extra_paholeopt} / -J ${extra_paholeopt} --skip_encoding_btf_enum64 /' scripts/link-vmlinux.sh
+        fi
+    fi
+
     # GCC 4.8
-    sed -i "s/CONFIG_CC_STACKPROTECTOR_STRONG=y/# CONFIG_CC_STACKPROTECTOR_STRONG is not set/g" .config
+    if [ "$HOSTCC" == "gcc-4.8" ]; then
+        scripts/config --disable CONFIG_CC_STACKPROTECTOR_STRONG
+        scripts/config --disable CONFIG_PPC_OF_BOOT_TRAMPOLINE
+    fi
 
     # Don't try to sign modules
-    sed -i "s/CONFIG_MODULE_SIG=y/# CONFIG_MODULE_SIG is not set/g" .config
+    scripts/config --disable CONFIG_MODULE_SIG
 
     # Disable kernel stack frame correctness validation, introduced in 4.6.0 and currently fails
-    sed -i "s/CONFIG_STACK_VALIDATION=y/# CONFIG_STACK_VALIDATION is not set/g" .config
+    scripts/config --disable CONFIG_STACK_VALIDATION
 
     # Cause problems with inline assembly on i386
-    sed -i "s/CONFIG_DEBUG_SECTION_MISMATCH=y/# CONFIG_DEBUG_SECTION_MISMATCH is not set/g" .config
+    scripts/config --disable CONFIG_DEBUG_SECTION_MISMATCH
+
+    # Don't build samples, they are broken on some kernel releases
+    scripts/config --disable CONFIG_SAMPLES
+    scripts/config --disable CONFIG_BUILD_DOCSRC
+
+    # Disable kcov
+    scripts/config --disable CONFIG_KCOV
+
+    # Broken on some RT kernels
+    scripts/config --disable CONFIG_HYPERV
+
+    # Broken drivers
+    scripts/config --disable CONFIG_RAPIDIO_TSI721
+    scripts/config --disable CONFIG_SGI_XP
+    scripts/config --disable CONFIG_MFD_WM8994
+    scripts/config --disable CONFIG_DRM_RADEON
+    scripts/config --disable CONFIG_SND_SOC_WM5100
+    # More recent compiler optimizations (from gcc 8 onwards )expose build errors
+    # with netronome on older kernels.
+    # Observed in 4.11-rt, 4.15-4.17, 5.0-rt - 5.16-rt
+    # It seems easier to disable the driver than to attempt patching.
+    # Eg.
+    #   In function ‘ur_load_imm_any’,
+    #   inlined from ‘jeq_imm’ at drivers/net/ethernet/netronome/nfp/bpf/jit.c:3146:13:
+    #   ./include/linux/compiler.h:350:45: error: call to ‘__compiletime_assert_1062’ declared with attribute error: FIELD_FIT: value too large for the field
+    #   350 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
+    #
+    scripts/config --disable CONFIG_NET_VENDOR_NETRONOME
+    # Eg.
+    #  In function ‘memcpy’,
+    #  inlined from ‘kszphy_get_strings’ at drivers/net/phy/micrel.c:664:3:
+    #  ./include/linux/string.h:305:25: error: call to ‘__read_overflow2’ declared with attribute error: detected read beyond size of object passed as 2nd parameter
+    #  305 |                         __read_overflow2();
+    #      |                         ^~~~~~~~~~~~~~~~~~
+    #  make[3]: *** [scripts/Makefile.build:308: drivers/net/phy/micrel.o] Error 1
+    #
+    scripts/config --disable CONFIG_MICREL_PHY
+
 
     # IGBVF won't build with recent gcc on 2.6.38.x
     if { vergte "$kversion" "2.6.37" && verlt "$kversion" "2.6.38"; }; then
-      sed -i "s/CONFIG_IGBVF=y/# CONFIG_IGBVF is not set/g" .config
+      scripts/config --disable CONFIG_IGBVF
     fi
 
-    # Set required options
-    {
-        echo "CONFIG_KPROBES=y";
-        echo "CONFIG_FTRACE=y";
-        echo "CONFIG_BLK_DEV_IO_TRACE=y";
-        echo "CONFIG_TRACEPOINTS=y";
-        echo "CONFIG_KALLSYMS_ALL=y";
-    } >> .config
+    # Don't fail the build on warnings
+    scripts/config --disable CONFIG_WERROR
+    scripts/config --enable CONFIG_PPC_DISABLE_WERROR
 
-    # Debug
-    #cat .config
+    # Set required options
+    scripts/config --enable CONFIG_TRACEPOINTS
+    scripts/config --enable CONFIG_KALLSYMS
+    scripts/config --enable CONFIG_HIGH_RES_TIMERS
+    scripts/config --enable CONFIG_KPROBES
+    scripts/config --enable CONFIG_FTRACE
+    scripts/config --enable CONFIG_BLK_DEV_IO_TRACE
+    scripts/config --enable CONFIG_KALLSYMS_ALL
+    scripts/config --enable CONFIG_HAVE_SYSCALL_TRACEPOINTS
+    scripts/config --enable CONFIG_PERF_EVENTS
+    scripts/config --enable CONFIG_EVENT_TRACING
+    scripts/config --enable CONFIG_KRETPROBES
+
+    if [ -n "${DEBUG}" ] ; then
+        cat .config
+    fi
 
-    make "$update_conf_target" CC="$CC"
-    make -j"$NPROC" CC="$CC"
+    make "$update_conf_target" "${make_args[@]}"
+    make -j"$NPROC" "${make_args[@]}"
 
-    krelease=$(make -s kernelrelease)
+    krelease=$(make -s kernelrelease "${make_args[@]}")
 
     # Save the kernel and modules
     mkdir -p "$LINUX_INSTOBJ_DIR/boot"
-    make INSTALL_MOD_PATH="$LINUX_INSTOBJ_DIR" INSTALL_MOD_STRIP=1 modules_install
-    make INSTALL_PATH="$LINUX_INSTOBJ_DIR/boot" install
+    make INSTALL_MOD_PATH="$LINUX_INSTOBJ_DIR" INSTALL_MOD_STRIP=1 modules_install "${make_args[@]}"
+    make INSTALL_MOD_PATH="$LINUX_INSTOBJ_DIR" INSTALL_PATH="$LINUX_INSTOBJ_DIR/boot" install "${make_args[@]}"
     rm -f "$LINUX_INSTOBJ_DIR/lib/modules/${krelease}/source" "$LINUX_INSTOBJ_DIR/lib/modules/${krelease}/build"
     ln -s ../../../../sources "$LINUX_INSTOBJ_DIR/lib/modules/${krelease}/source"
     ln -s ../../../../sources "$LINUX_INSTOBJ_DIR/lib/modules/${krelease}/source"
@@ -275,9 +635,13 @@ extract_distro_headers() {
     rm -f "${LINUX_HDROBJ_DIR}/scripts/*.o"
     rm -f "${LINUX_HDROBJ_DIR}/scripts/*/*.o"
 
-    # On powerpc this object is required to link modules
+    # On powerpc 32bits this object is required to link modules
     if [ "${karch}" = "powerpc" ]; then
-        cp -a --parents arch/powerpc/lib/crtsavres.[So] "${LINUX_HDROBJ_DIR}/"
+        if [ "x$(scripts/config -s CONFIG_PPC64)" = "xy" ] && vergte "${kversion}" "5.4"; then
+            :
+        else
+            cp -a --parents arch/powerpc/lib/crtsavres.[So] "${LINUX_HDROBJ_DIR}/"
+        fi
     fi
 
     # On arm64 between 4.13 and 1.15 this object is required to build with ftrace support
@@ -325,23 +689,29 @@ extract_distro_headers() {
     touch -r "${LINUX_HDROBJ_DIR}/.config" "${LINUX_HDROBJ_DIR}/include/generated/autoconf.h"
 
     # Copy .config to include/config/auto.conf so "make prepare" is unnecessary.
-    cp "${LINUX_HDROBJ_DIR}/.config" "${LINUX_HDROBJ_DIR}/include/config/auto.conf"
+    if [ ! -f "${LINUX_HDROBJ_DIR}/include/config/auto.conf" ]; then
+        cp "${LINUX_HDROBJ_DIR}/.config" "${LINUX_HDROBJ_DIR}/include/config/auto.conf"
+    fi
 
     # Finally clean the object files from the full source tree
     make clean
 
     # And regen the modules support files
-    make modules_prepare CC="$CC"
+    make modules_prepare "${make_args[@]}"
 
-    # On powerpc this object is required to link modules
+    # On powerpc 32bits this object is required to link modules
     if [ "${karch}" = "powerpc" ]; then
-        make arch/powerpc/lib/crtsavres.o CC="$CC"
+        if [ "x$(scripts/config -s CONFIG_PPC64)" = "xy" ] && vergte "${kversion}" "5.4"; then
+            :
+        else
+            make arch/powerpc/lib/crtsavres.o "${make_args[@]}"
+        fi
     fi
 
     # On arm64 between 4.13 and 4.15 this object is required to build with ftrace support
     if [ "${karch}" = "arm64" ]; then
         if [ -f "arch/arm64/kernel/ftrace-mod.S" ]; then
-            make arch/arm64/kernel/ftrace-mod.o CC="$CC"
+            make arch/arm64/kernel/ftrace-mod.o "${make_args[@]}"
         fi
     fi
 
@@ -365,6 +735,10 @@ build_modules() {
 
     kversion=$(make -C "$LINUX_HDROBJ_DIR" -s kernelversion)
 
+    # Try to catch some compatibility problems by turning some
+    # warnings into errors.
+    #export KCFLAGS="$KCFLAGS -Wall -Werror"
+
     # Enter lttng-modules source dir
     cd "${MODULES_GIT_DIR}"
 
@@ -376,12 +750,13 @@ build_modules() {
         set +e
 
         # Build modules
-        KERNELDIR="${kdir}" make -j"${NPROC}" V=1 CC="$CC"
+        KERNELDIR="${kdir}" make -j"${NPROC}" V=1 "${make_args[@]}"
+	ret=$?
 
         set -e
 
         # We expect this build to fail, if it doesn't, fail the job.
-        if [ "$?" -eq 0 ]; then
+        if [ "$ret" -eq 0 ]; then
             echo "This build should have failed."
             exit 1
         fi
@@ -389,14 +764,12 @@ build_modules() {
         # We have to publish at least one file or the build will fail
         echo "This kernel is broken, there is a deadlock in the timekeeping subsystem." > "${outdir}/BROKEN.txt.ko"
 
-        set -e
-
         KERNELDIR="${kdir}" make clean
 
     else # Regular build
 
         # Build modules against full kernel sources
-        KERNELDIR="${kdir}" make -j"${NPROC}" V=1 CC="$CC"
+        KERNELDIR="${kdir}" make -j"${NPROC}" V=1 "${make_args[@]}"
 
         # Install modules to build dir
         KERNELDIR="${kdir}" make INSTALL_MOD_PATH="${outdir}" modules_install
@@ -441,14 +814,14 @@ if [ "x${cross_arch}" != "x" ]; then
         "armhf")
             karch="arm"
             cross_compile="arm-linux-gnueabihf-"
-            vanilla_config="allyesconfig"
+            vanilla_config="imx_v6_v7_defconfig"
             ubuntu_config="armhf-config.flavour.generic"
             ;;
 
         "arm64")
             karch="arm64"
             cross_compile="aarch64-linux-gnu-"
-            vanilla_config="allyesconfig"
+            vanilla_config="defconfig"
             ubuntu_config="arm64-config.flavour.generic"
             ;;
 
@@ -480,39 +853,39 @@ if [ "x${cross_arch}" != "x" ]; then
 elif [ "x${arch}" != "x" ]; then
 
     case "$arch" in
-        "x86-32")
+        "i386")
             karch="x86"
-            vanilla_config="allyesconfig"
+            vanilla_config="allmodconfig"
             ubuntu_config="i386-config.flavour.generic"
             ;;
 
-        "x86-64")
+        "amd64")
             karch="x86"
-            vanilla_config="allyesconfig"
+            vanilla_config="allmodconfig"
             ubuntu_config="amd64-config.flavour.generic"
             ;;
 
         "armhf")
             karch="arm"
-            vanilla_config="allyesconfig"
+            vanilla_config="allmodconfig"
             ubuntu_config="armhf-config.flavour.generic"
             ;;
 
         "arm64")
             karch="arm64"
-            vanilla_config="allyesconfig"
+            vanilla_config="allmodconfig"
             ubuntu_config="arm64-config.flavour.generic"
             ;;
 
         "powerpc")
             karch="powerpc"
-            vanilla_config="allyesconfig"
+            vanilla_config="allmodconfig"
             ubuntu_config="powerpc-config.flavour.powerpc-smp"
             ;;
 
         "ppc64el")
             karch="powerpc"
-            vanilla_config="allyesconfig"
+            vanilla_config="allmodconfig"
             ubuntu_config="ppc64el-config.flavour.generic"
             ;;
 
@@ -522,7 +895,7 @@ elif [ "x${arch}" != "x" ]; then
             ;;
     esac
 else
-    echo "Not arch or cross_arch specified"
+    echo "No arch or cross_arch specified"
     exit 1
 fi
 
@@ -544,18 +917,28 @@ secret_key = echo123456
 # Enable S3 v4 signature APIs
 signature_v2 = False" > "$WORKSPACE/.s3cfg"
 
-url_hash="$(echo -n "$kgitrepo/$ktag/$arch/$cross_arch" | md5sum | awk '{ print $1 }')"
+url_hash="$(echo -n "$kgitrepo" | md5sum | awk '{ print $1 }')"
 obj_name="linux.tar.bz2"
-obj_url_prefix="$OBJ_STORE_URL/linux-build/$url_hash"
+
+if [ "x${cross_arch}" = "x" ]; then
+	obj_url_prefix="$OBJ_STORE_URL/linux-build/$url_hash/$ktag/platform-${platforms}/$arch/native"
+else
+	obj_url_prefix="$OBJ_STORE_URL/linux-build/$url_hash/$ktag/platform-${platforms}/${cross_arch}"
+fi
+
 obj_url="$obj_url_prefix/$obj_name"
 
 set +e
-s3cmd -c "$WORKSPACE/.s3cfg" get "$obj_url"
+# In s3cmd 2.3, the return code of get when an object does not exist (64)
+# is different than in 2.2 (12). The return codes of 's3cmd info' are
+# consistent between 2.2 and 2.3.
+s3cmd -c "$WORKSPACE/.s3cfg" info "$obj_url"
 ret=$?
 set -e
 
 case "$ret" in
     "0")
+      s3cmd -c "$WORKSPACE/.s3cfg" get "$obj_url"
       extract_archive_obj
       ;;
 
@@ -590,6 +973,14 @@ esac
 
 select_compiler
 
+selected_cc_version="$(echo "${selected_cc}" | cut -d'-' -f2)"
+# lttng-modules requires gcc >= 5.1 for aarch64
+# @see https://github.com/lttng/lttng-modules/commit/be06402dbdbea2f3394e60ec15c5d3356e2be416
+if { verlt "${selected_cc_version}" "5.1"; } && [ "${cross_arch}" = "arm64" ] ; then
+    echo "Building lltng-modules on aarch64 requires gcc >= 5.1"
+    exit 0
+fi
+
 ## BUILD modules
 # Either we downloaded a pre-build kernel or we built it and uploaded
 # the archive for future builds.