genbtf.sh

#!/bin/bash

# SPDX-License-Identifier: Apache-2.0
# Copyright (c) 2024 Elastic NV

Script=${0##*/}

function usage
{
   echo "usage: $Script path-to-btfhub-archive" 1>&2
   exit 1
}

function die {
	printf "%s: %s\n" "$Script" "$1" 1>&2
	exit 1
}

if [ $# -ne 1 ]; then
   usage
fi

Btfhub_path="$1"

Srcs_amd64="
amzn/2/x86_64
amzn/2018/x86_64
centos/7/x86_64
centos/8/x86_64
debian/bullseye/x86_64
debian/9/x86_64
debian/10/x86_64
fedora/24/x86_64
fedora/25/x86_64
fedora/26/x86_64
fedora/27/x86_64
fedora/28/x86_64
fedora/29/x86_64
fedora/30/x86_64
fedora/31/x86_64
ol/7/x86_64
ol/8/x86_64
rhel/7/x86_64
rhel/8/x86_64
sles/12.3
sles/12.5
sles/15.3
ubuntu/16.04/x86_64
ubuntu/18.04/x86_64
ubuntu/20.04/x86_64
"

Srcs_arm64="
amzn/2/arm64
centos/7/arm64
centos/8/arm64
debian/bullseye/arm64
debian/9/arm64
debian/10/arm64
fedora/28/arm64
fedora/29/arm64
fedora/30/arm64
fedora/31/arm64
ol/7/arm64
ol/8/arm64
rhel/7/arm64
rhel/8/arm64
ubuntu/16.04/arm64
ubuntu/18.04/arm64
ubuntu/20.04/arm64
"

# Table of all successfull kernels, so we can create all_btfs[]
typeset -a Good_amd64
typeset -a Good_arm64
typeset -i Total=0

Commit=$(cd "$Btfhub_path" && git rev-parse HEAD)
if [ -z "$Commit" ]; then
	exit 1
fi

cat <<EOF
// SPDX-License-Identifier: Apache-2.0
/* Copyright (c) 2024 Elastic NV */

#include "quark.h"

/*
 * THIS FILE IS AUTOGENERATED! Resist all urges to ruin its spirit manually!
 *
 * You can happily generate this through:
 * $ make btfhub BTFHUB_ARCHIVE_PATH=/my/path/to/a/btfhub-archive
 *
 * Grab a beer as this takes some time. It's 3000 files for amd64 only.
 */

EOF

printf "const char *btfhub_archive_commit=\"%s\";\n\n" "$Commit"

function do_arch
{
	if [ "$1" = amd64 ]; then
		arch=amd64
		srcs="$Srcs_amd64"
	elif [ "$1" = arm64 ]; then
		arch=aarch64
		srcs="$Srcs_arm64"
	else
		die "bad arch"
	fi

	printf "#ifdef __%s__\n\n" $arch

	for s in $srcs; do
		distro=${s%/*}
		s="$Btfhub_path/$s"
		while IFS= read -r -d '' k
		do
			btf=$(basename "${k%%.tar.xz}")
			version="${btf%%.btf}"
			tar xf "$k" || die "oh noes"
			name=${distro}_${version}
			name=$(echo "$name" | tr \\055\\056\\057 _)
			if ./quark-btf -g "$btf" "$distro" "$version" 2>/dev/null; then
				echo "$name OK" 1>&2
				if [ "$1" = amd64 ]; then
					Good_amd64+=("$name")
				elif [ "$1" = arm64 ]; then
					Good_arm64+=("$name")
				fi
			else
				echo "$name FAIL" 1>&2
			fi
			rm -f "$btf"
			Total=$((Total+1))
		done < <(find "$s" -name '*.tar.xz' -print0)
		# for k in $(find "$s" -name '*.tar.xz'); do
		# done
	done

	printf "#endif /* __%s__ */\n\n" $arch

}

do_arch amd64
do_arch arm64

cat <<EOF
struct quark_btf *all_btfs[] = {
EOF

	printf "\n#ifdef __amd64__\n"
	for name in "${Good_amd64[@]}"; do
		printf "\t&%s,\n" "$name"
	done
	printf "#endif /* __amd64__ */\n\n"

	printf "#ifdef __aarch64__\n"
	for name in "${Good_arm64[@]}"; do
		printf "\t&%s,\n" "$name"
	done
	printf "#endif /* __aarch64__ */\n\n"

cat <<EOF
	NULL
};

EOF

typeset -i Good_count
Good_count=$((${#Good_amd64[@]} + ${#Good_arm64[@]}))
printf "%d/%d succeeded\n" $Good_count $Total 1>&2