update 2026-10-27 11:22:48

vmlinux-btf/.github/workflows/build.yml

@@ -0,0 +1,252 @@
+name: Build packages
+
+on:
+  workflow_dispatch:
+    inputs:
+      openwrt_majors:
+        description: 'OpenWrt major versions (space-separated, e.g. 24 25)'
+        required: false
+        default: '24 25'
+        type: string
+  push:
+    branches:
+      - master
+
+permissions:
+  contents: write
+  actions: write
+
+env:
+  OPENWRT_MAJORS: '24 25'
+
+jobs:
+  prepare:
+    name: Prepare version and matrix
+    runs-on: ubuntu-latest
+    outputs:
+      release_tag: ${{ steps.matrix.outputs.release_tag }}
+      release_name: ${{ steps.matrix.outputs.release_name }}
+      sdks: ${{ steps.matrix.outputs.sdks }}
+    steps:
+      - name: Checkout source
+        uses: actions/checkout@v6
+
+      - name: Resolve latest SDK releases and metadata
+        id: matrix
+        shell: bash
+        run: |
+          set -euo pipefail
+
+          raw_majors="${{ inputs.openwrt_majors }}"
+          majors=$(echo "${raw_majors:-$OPENWRT_MAJORS}" | tr ',' ' ')
+          echo "Target major versions: ${majors}"
+
+          tags=""
+          for i in {1..3}; do
+            tags=$(git ls-remote --tags --refs https://github.com/openwrt/openwrt.git 2>/dev/null | awk -F'/' '{print $NF}' | sed 's/^v//' || true)
+            [ -n "$tags" ] && break
+            sleep 2
+          done
+
+          if [ -z "$tags" ]; then
+            echo "::error::Failed to fetch tags from https://github.com/openwrt/openwrt.git"
+            exit 1
+          fi
+
+          sdks=()
+          for major in $majors; do
+            latest=$(echo "$tags" | grep -E "^${major}\.[0-9.]+$" | sort -V | tail -n 1 || true)
+            [ -z "$latest" ] && latest=$(echo "$tags" | grep -E "^${major}\." | sort -V | tail -n 1 || true)
+
+            if [ -n "$latest" ]; then
+              echo "OpenWrt ${major} -> ${latest}"
+              sdks+=("$latest")
+            else
+              echo "::error::No OpenWrt release tag found for major: ${major}"
+              exit 1
+            fi
+          done
+
+          echo "sdks=$(jq -nc --args '$ARGS.positional' -- "${sdks[@]}")" >> "$GITHUB_OUTPUT"
+
+          pkg_release=$(grep '^PKG_RELEASE:=' Makefile | head -n 1 | cut -d= -f2 | tr -d '[:space:]')
+          date_tag=$(date +'%Y%m%d')
+          short_sha=$(git rev-parse --short HEAD)
+
+          target_vers=$(IFS=, ; echo "${sdks[*]}")
+          target_vers_tag=$(IFS=_ ; echo "${sdks[*]}")
+
+          release_name="vmlinux-btf r${pkg_release} for OpenWrt ${target_vers} (${date_tag})"
+          release_tag="vmlinux-btf_r${pkg_release}_openwrt-${target_vers_tag}_${date_tag}_${short_sha}"
+
+          echo "release_name=${release_name}" >> "$GITHUB_OUTPUT"
+          echo "release_tag=${release_tag}" >> "$GITHUB_OUTPUT"
+
+          echo "Release name: ${release_name}"
+          echo "Release tag: ${release_tag}"
+
+  build:
+    name: Build ${{ matrix.arch }}-openwrt-${{ matrix.sdk }}
+    runs-on: ubuntu-latest
+    needs: prepare
+    strategy:
+      fail-fast: false
+      matrix:
+        arch:
+          - aarch64_generic
+          - aarch64_cortex-a53
+          - aarch64_cortex-a72
+          - aarch64_cortex-a76
+          - x86_64
+        sdk: ${{ fromJson(needs.prepare.outputs.sdks) }}
+
+    steps:
+      - name: Checkout source
+        uses: actions/checkout@v6
+
+      - name: Build packages with OpenWrt SDK
+        shell: bash
+        run: |
+          set -euo pipefail
+          mkdir -p artifacts feed/vmlinux-btf
+          cp -a Makefile src feed/vmlinux-btf/
+          [ ! -f README.md ] || cp -a README.md feed/vmlinux-btf/
+
+          image="docker.io/openwrt/sdk:${{ matrix.arch }}-${{ matrix.sdk }}"
+          echo "Pulling SDK image ${image}..."
+          docker pull "${image}"
+
+          docker run --rm \
+            --user root \
+            -v "${{ github.workspace }}/feed:/feed:ro" \
+            -v "${{ github.workspace }}/artifacts:/artifacts" \
+            "${image}" \
+            bash -c '
+              set -e
+              # Install host dwarves/pahole (Bullseye has dwarves; Bookworm/Alpine have dwarves/pahole)
+              if command -v apt-get >/dev/null 2>&1; then
+                if [ -f /etc/debian_version ] && grep -q '^11' /etc/debian_version; then
+                  printf "deb [check-valid-until=no trusted=yes] http://archive.debian.org/debian/ bullseye main\ndeb [check-valid-until=no trusted=yes] http://archive.debian.org/debian-security/ bullseye-security main\n" > /etc/apt/sources.list
+                  rm -rf /etc/apt/sources.list.d/*
+                fi
+                apt-get update -o Acquire::Check-Valid-Until=false || apt-get update
+                apt-get install -y --no-install-recommends dwarves llvm || apt-get install -y dwarves llvm || apt-get install -y pahole
+                rm -rf /var/lib/apt/lists/*
+              elif command -v apk >/dev/null 2>&1; then
+                apk add --no-cache dwarves
+              fi
+
+              # Verify pahole binary exists and is executable
+              pahole_bin="$(command -v pahole || which pahole || true)"
+              if [ -z "$pahole_bin" ] || [ ! -x "$pahole_bin" ]; then
+                echo "::error::pahole binary not found after package installation"
+                exit 1
+              fi
+              echo "Using pahole binary: $pahole_bin ($("$pahole_bin" --version))"
+
+              # Ensure pahole is accessible within OpenWrt staging_dir host tools
+              mkdir -p /builder/staging_dir/host/bin
+              ln -sf "$pahole_bin" /builder/staging_dir/host/bin/pahole
+
+              # Ensure real llvm-objcopy is accessible within OpenWrt staging_dir host tools
+              llvm_objcopy_bin="$(command -v llvm-objcopy || find /usr/bin -name 'llvm-objcopy*' 2>/dev/null | head -n 1 || true)"
+              if [ -n "$llvm_objcopy_bin" ]; then
+                ln -sf "$llvm_objcopy_bin" /builder/staging_dir/host/bin/llvm-objcopy
+                echo "Using llvm-objcopy: $llvm_objcopy_bin"
+              fi
+
+              # Fix permissions and compile as buildbot user
+              chown -R 1000:1000 /builder /artifacts
+              su -s /bin/bash buildbot -c '\''
+                set -e
+                [ ! -f setup.sh ] || bash setup.sh
+                echo "src-link packages_ci /feed" > feeds.conf
+                ./scripts/feeds update packages_ci
+                ./scripts/feeds install -p packages_ci vmlinux-btf
+                echo "CONFIG_PACKAGE_vmlinux-btf=m" >> .config
+                make defconfig
+                make package/vmlinux-btf/compile V=s
+                mkdir -p /artifacts/bin
+                cp -a bin/* /artifacts/bin/ 2>/dev/null || true
+              '\''
+            '
+
+          sudo chown -R "$USER:$USER" "${{ github.workspace }}/artifacts"
+
+      - name: Show built files
+        shell: bash
+        run: |
+          echo "=== Built package files ==="
+          find artifacts -type f \( -name "vmlinux-btf*.ipk" -o -name "vmlinux-btf*.apk" \) || true
+          echo "==========================="
+
+      - name: Prepare renamed artifacts
+        shell: bash
+        run: |
+          set -euo pipefail
+          mkdir -p dist
+          found=0
+          while IFS= read -r f; do
+            [ -n "$f" ] || continue
+            found=1
+            base="$(basename "$f")"
+            ext="${base##*.}"
+            name="${base%.*}"
+
+            if [[ "$name" == *"${{ matrix.arch }}"* ]] || [[ "$name" == *"all"* ]]; then
+              new_name="${name}-openwrt-${{ matrix.sdk }}.${ext}"
+            else
+              new_name="${name}-${{ matrix.arch }}-openwrt-${{ matrix.sdk }}.${ext}"
+            fi
+
+            cp "$f" "dist/${new_name}"
+          done < <(find artifacts -type f \( -name "vmlinux-btf*.ipk" -o -name "vmlinux-btf*.apk" \) 2>/dev/null)
+
+          if [ "$found" -eq 0 ]; then
+            echo "::error::No package files found in artifacts"
+            exit 1
+          fi
+
+          ls -lah dist
+
+      - name: Upload build artifacts
+        uses: actions/upload-artifact@v7
+        with:
+          name: ${{ matrix.arch }}-openwrt-${{ matrix.sdk }}
+          path: dist/*
+          if-no-files-found: error
+          compression-level: 0
+          retention-days: 3
+
+  release:
+    name: Publish release
+    runs-on: ubuntu-latest
+    needs:
+      - prepare
+      - build
+    steps:
+      - name: Download all build artifacts
+        uses: actions/download-artifact@v8
+        with:
+          path: release-dist
+          merge-multiple: true
+
+      - name: Create or update GitHub release
+        uses: softprops/action-gh-release@v3
+        with:
+          tag_name: ${{ needs.prepare.outputs.release_tag }}
+          name: ${{ needs.prepare.outputs.release_name }}
+          files: release-dist/*
+          generate_release_notes: true
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Delete Old Releases
+        uses: ophub/delete-releases-workflows@main
+        with:
+          delete_releases: true
+          releases_keep_latest: 3
+          delete_tags: true
+          delete_workflows: true
+          workflows_keep_day: 3
+          gh_token: ${{ secrets.GITHUB_TOKEN }}
+        continue-on-error: true

vmlinux-btf/Makefile

@@ -0,0 +1,102 @@
+#
+# Copyright (C) 2015-2024 OpenWrt.org
+#
+# This is free software, licensed under the GNU General Public License v3.
+#
+
+VMLINUX_BTF_DIR := $(patsubst %/,%,$(dir $(lastword $(MAKEFILE_LIST))))
+
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/kernel.mk
+
+PKG_NAME:=vmlinux-btf
+PKG_VERSION:=$(LINUX_VERSION)
+PKG_RELEASE:=9
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/vmlinux-btf
+  SECTION:=kernel
+  CATEGORY:=Kernel
+  TITLE:=Kernel vmlinux.btf for CO-RE compatibility
+endef
+
+define Package/vmlinux-btf/description
+  Generates detached kernel BTF from target kernel headers and config,
+  enabling CO-RE eBPF programs on OpenWrt without rebuilding the kernel.
+endef
+
+define Package/vmlinux-btf/postinst
+#!/bin/sh
+[ -n "$${IPKG_INSTROOT}" ] || ln -sf vmlinux /usr/lib/debug/boot/vmlinux-$$(uname -r)
+endef
+
+define Package/vmlinux-btf/prerm
+#!/bin/sh
+[ -n "$${IPKG_INSTROOT}" ] || rm -f /usr/lib/debug/boot/vmlinux-$$(uname -r)
+endef
+
+BTF_CC ?= $(if $(TARGET_CC_NOCACHE),$(TARGET_CC_NOCACHE),$(TARGET_CROSS)gcc)
+BTF_PAHOLE ?= $(firstword \
+	$(wildcard $(STAGING_DIR_HOST)/bin/pahole /usr/bin/pahole /usr/local/bin/pahole) \
+	$(shell command -v pahole 2>/dev/null) \
+	pahole)
+KERNEL_RELEASE := $(if $(wildcard $(LINUX_DIR)/include/config/kernel.release),$(shell cat $(LINUX_DIR)/include/config/kernel.release),$(LINUX_VERSION))
+
+BTF_CFLAGS := \
+	-nostdinc \
+	-isystem $(shell $(BTF_CC) -print-file-name=include) \
+	-D__KERNEL__ \
+	-include $(LINUX_DIR)/include/linux/kconfig.h \
+	$(if $(wildcard $(LINUX_DIR)/include/linux/compiler-version.h),-include $(LINUX_DIR)/include/linux/compiler-version.h) \
+	$(if $(wildcard $(LINUX_DIR)/include/linux/compiler_types.h),-include $(LINUX_DIR)/include/linux/compiler_types.h) \
+	-I$(LINUX_DIR)/arch/$(LINUX_KARCH)/include \
+	-I$(LINUX_DIR)/arch/$(LINUX_KARCH)/include/generated \
+	-I$(LINUX_DIR)/include \
+	-I$(LINUX_DIR)/include/generated \
+	-I$(LINUX_DIR)/arch/$(LINUX_KARCH)/include/uapi \
+	-I$(LINUX_DIR)/arch/$(LINUX_KARCH)/include/generated/uapi \
+	-I$(LINUX_DIR)/include/uapi \
+	-I$(LINUX_DIR)/include/generated/uapi \
+	-I$(LINUX_DIR) \
+	$(filter -m% -march=% -mcpu=% -mtune=% -EB -EL,$(TARGET_CFLAGS)) \
+	-std=gnu11 -funsigned-char -fshort-wchar -fno-common -fno-PIE \
+	-O2 -g -gdwarf-4 -fno-eliminate-unused-debug-types \
+	-Wno-error -Wno-unused-function -Wno-unused-variable
+
+define Build/Prepare
+	mkdir -p $(PKG_BUILD_DIR)
+	$(CP) $(VMLINUX_BTF_DIR)/src/* $(PKG_BUILD_DIR)/
+endef
+
+define Build/Compile
+	@if [ ! -f "$(LINUX_DIR)/include/generated/autoconf.h" ]; then \
+		echo "vmlinux-btf: kernel headers not found in $(LINUX_DIR)"; \
+		exit 1; \
+	fi
+	@if [ -z "$(BTF_PAHOLE)" ] || ! $(BTF_PAHOLE) --version >/dev/null 2>&1; then \
+		echo "vmlinux-btf: pahole not found or not working (install dwarves/pahole on host)"; \
+		exit 1; \
+	fi
+
+	$(BTF_CC) $(BTF_CFLAGS) -c $(PKG_BUILD_DIR)/shadow_btf_core.c -o $(PKG_BUILD_DIR)/shadow_btf_core.o
+	-$(BTF_CC) $(BTF_CFLAGS) -c $(PKG_BUILD_DIR)/shadow_btf_modules.c -o $(PKG_BUILD_DIR)/shadow_btf_modules.o 2>/dev/null
+	-$(BTF_CC) $(BTF_CFLAGS) -c $(PKG_BUILD_DIR)/shadow_btf_private.c -o $(PKG_BUILD_DIR)/shadow_btf_private.o 2>/dev/null
+	$(TARGET_CROSS)ld -r -o $(PKG_BUILD_DIR)/shadow_btf.o $(PKG_BUILD_DIR)/shadow_btf_*.o
+	if $(BTF_PAHOLE) --help 2>&1 | grep -q -- '--btf_encode_detached'; then \
+		$(BTF_PAHOLE) --btf_encode_detached=$(PKG_BUILD_DIR)/vmlinux-btf $(PKG_BUILD_DIR)/shadow_btf.o; \
+	else \
+		$(BTF_PAHOLE) -J $(PKG_BUILD_DIR)/shadow_btf.o && \
+		$(TARGET_CROSS)objcopy --dump-section .BTF=$(PKG_BUILD_DIR)/vmlinux-btf $(PKG_BUILD_DIR)/shadow_btf.o; \
+	fi
+	test -s $(PKG_BUILD_DIR)/vmlinux-btf
+	$(BTF_PAHOLE) -C sk_buff $(PKG_BUILD_DIR)/shadow_btf.o >/dev/null
+endef
+
+define Package/vmlinux-btf/install
+	$(INSTALL_DIR) $(1)/usr/lib/debug/boot
+	$(INSTALL_DATA) $(PKG_BUILD_DIR)/vmlinux-btf $(1)/usr/lib/debug/boot/vmlinux
+	$(LN) vmlinux $(1)/usr/lib/debug/boot/vmlinux-$(KERNEL_RELEASE)
+endef
+
+$(eval $(call BuildPackage,vmlinux-btf))

vmlinux-btf/README.md

@@ -0,0 +1,42 @@
+# vmlinux-btf
+
+OpenWrt package that generates a detached BTF (`vmlinux`) file from kernel headers and `.config`, enabling CO-RE (Compile Once – Run Everywhere) eBPF programs on OpenWrt without rebuilding or replacing the running kernel.
+
+## Overview
+
+Official OpenWrt release kernels typically omit `CONFIG_DEBUG_INFO_BTF=y`. Without kernel BTF, modern eBPF tools that rely on CO-RE (such as `libbpf`-based loaders) cannot resolve kernel type layouts.
+
+Rather than recompiling the entire kernel tree, this package compiles lightweight stub sources (`src/shadow_btf_*.c`) against the prepared target kernel headers (`$(LINUX_DIR)`) using the target configuration and toolchain. `pahole` then extracts the detached BTF blob from the linked object.
+
+## Requirements
+
+- OpenWrt buildroot or SDK environment.
+- Host `pahole` >= 1.22 (from the `dwarves` package).
+
+## Building
+
+### In OpenWrt SDK
+
+```bash
+git clone https://github.com/QiuSimons/vmlinux-btf.git package/vmlinux-btf
+make package/vmlinux-btf/compile V=s
+```
+
+### In OpenWrt Buildroot
+
+Select `vmlinux-btf` under `Kernel` in `make menuconfig`, then build:
+
+```bash
+make package/vmlinux-btf/compile V=s
+```
+
+## Installed Files
+
+- `/usr/lib/debug/boot/vmlinux`: Detached BTF file.
+- `/usr/lib/debug/boot/vmlinux-<release>`: Symlink targeting `vmlinux` (linked to `uname -r` on target installation).
+
+Standard loaders such as `libbpf` look for BTF at `/usr/lib/debug/boot/vmlinux-$(uname -r)` and `/usr/lib/debug/boot/vmlinux` by default.
+
+## License
+
+GPL-3.0-or-later

vmlinux-btf/src/shadow_btf_core.c

@@ -0,0 +1,76 @@
+#include <linux/kconfig.h>
+
+#ifndef KBUILD_MODNAME
+#define KBUILD_MODNAME "shadow_btf_core"
+#endif
+#ifndef KBUILD_BASENAME
+#define KBUILD_BASENAME "shadow_btf_core"
+#endif
+
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/sched.h>
+#include <linux/mm_types.h>
+#include <linux/fs.h>
+#include <linux/dcache.h>
+#include <linux/cred.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/icmp.h>
+#include <linux/bpf.h>
+#include <linux/bpf_perf_event.h>
+#include <net/sock.h>
+#include <net/inet_sock.h>
+#include <net/inet_connection_sock.h>
+#include <net/net_namespace.h>
+#include <net/dst.h>
+#include <net/neighbour.h>
+#include <net/xdp.h>
+#include <net/ip.h>
+
+#if __has_include(<net/netdev_rx_queue.h>)
+#include <net/netdev_rx_queue.h>
+#endif
+
+#if __has_include(<linux/bpf_iter.h>)
+#include <linux/bpf_iter.h>
+#endif
+
+#if IS_ENABLED(CONFIG_CGROUPS)
+#include <linux/cgroup.h>
+#endif
+
+#define BTF_KEEP(name, type) \
+	static type * __attribute__((used, section(".discard.btf_keep"))) \
+		__btf_keep_##name
+
+BTF_KEEP(pt_regs, struct pt_regs);
+BTF_KEEP(task_struct, struct task_struct);
+BTF_KEEP(mm_struct, struct mm_struct);
+BTF_KEEP(file, struct file);
+BTF_KEEP(dentry, struct dentry);
+BTF_KEEP(inode, struct inode);
+BTF_KEEP(cred, struct cred);
+BTF_KEEP(module, struct module);
+BTF_KEEP(sk_buff, struct sk_buff);
+BTF_KEEP(net_device, struct net_device);
+BTF_KEEP(netdev_queue, struct netdev_queue);
+BTF_KEEP(netdev_rx_queue, struct netdev_rx_queue);
+BTF_KEEP(sock, struct sock);
+BTF_KEEP(inet_sock, struct inet_sock);
+BTF_KEEP(inet_connection_sock, struct inet_connection_sock);
+BTF_KEEP(tcp_sock, struct tcp_sock);
+BTF_KEEP(udp_sock, struct udp_sock);
+BTF_KEEP(net, struct net);
+BTF_KEEP(dst_entry, struct dst_entry);
+BTF_KEEP(neighbour, struct neighbour);
+BTF_KEEP(xdp_buff, struct xdp_buff);
+BTF_KEEP(bpf_perf_event_data, struct bpf_perf_event_data);
+#if IS_ENABLED(CONFIG_CGROUPS)
+BTF_KEEP(cgroup, struct cgroup);
+#endif

vmlinux-btf/src/shadow_btf_modules.c

@@ -0,0 +1,79 @@
+#include <linux/kconfig.h>
+
+#ifndef KBUILD_MODNAME
+#define KBUILD_MODNAME "shadow_btf_modules"
+#endif
+#ifndef KBUILD_BASENAME
+#define KBUILD_BASENAME "shadow_btf_modules"
+#endif
+
+#include <linux/types.h>
+
+#define BTF_KEEP(name, type) \
+	static type * __attribute__((used, section(".discard.btf_keep"))) \
+		__btf_keep_##name
+
+#if IS_ENABLED(CONFIG_INET)
+#include <net/route.h>
+#include <net/ip_fib.h>
+BTF_KEEP(rtable, struct rtable);
+#endif
+
+#if IS_ENABLED(CONFIG_IPV6)
+#include <net/ipv6.h>
+#include <net/if_inet6.h>
+BTF_KEEP(ipv6_pinfo, struct ipv6_pinfo);
+#endif
+
+#if IS_ENABLED(CONFIG_NETFILTER)
+#include <linux/netfilter.h>
+BTF_KEEP(nf_hook_state, struct nf_hook_state);
+#endif
+
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_tuple.h>
+BTF_KEEP(nf_conn, struct nf_conn);
+BTF_KEEP(nf_conntrack_tuple, struct nf_conntrack_tuple);
+#endif
+
+#if IS_ENABLED(CONFIG_NF_NAT) && __has_include(<net/netfilter/nf_nat.h>)
+#include <net/netfilter/nf_nat.h>
+BTF_KEEP(nf_conn_nat, struct nf_conn_nat);
+#endif
+
+#if IS_ENABLED(CONFIG_NF_TABLES) && __has_include(<net/netfilter/nf_tables.h>)
+#include <net/netfilter/nf_tables.h>
+BTF_KEEP(nft_pktinfo, struct nft_pktinfo);
+#endif
+
+#if IS_ENABLED(CONFIG_NF_FLOW_TABLE) && __has_include(<net/netfilter/nf_flow_table.h>)
+#include <net/netfilter/nf_flow_table.h>
+BTF_KEEP(flow_offload, struct flow_offload);
+#endif
+
+#if IS_ENABLED(CONFIG_NETFILTER_XTABLES)
+#include <linux/netfilter/x_tables.h>
+BTF_KEEP(xt_table, struct xt_table);
+BTF_KEEP(xt_action_param, struct xt_action_param);
+#endif
+
+#if IS_ENABLED(CONFIG_NET_SCHED)
+#include <net/sch_generic.h>
+#include <net/pkt_sched.h>
+BTF_KEEP(qdisc, struct Qdisc);
+#endif
+
+#if IS_ENABLED(CONFIG_NET_CLS) && __has_include(<net/pkt_cls.h>)
+#include <net/pkt_cls.h>
+BTF_KEEP(tcf_result, struct tcf_result);
+#endif
+
+#if IS_ENABLED(CONFIG_NET_CLS_ACT) && __has_include(<net/act_api.h>)
+#include <net/act_api.h>
+#endif
+
+#if IS_ENABLED(CONFIG_XDP_SOCKETS) && __has_include(<net/xdp_sock.h>)
+#include <net/xdp_sock.h>
+BTF_KEEP(xdp_sock, struct xdp_sock);
+#endif

vmlinux-btf/src/shadow_btf_private.c

@@ -0,0 +1,23 @@
+#include <linux/kconfig.h>
+
+#ifndef KBUILD_MODNAME
+#define KBUILD_MODNAME "shadow_btf_private"
+#endif
+#ifndef KBUILD_BASENAME
+#define KBUILD_BASENAME "shadow_btf_private"
+#endif
+
+#define BTF_KEEP(name, type) \
+	static type * __attribute__((used, section(".discard.btf_keep"))) \
+		__btf_keep_##name
+
+#if IS_ENABLED(CONFIG_BRIDGE) && __has_include("net/bridge/br_private.h")
+#include "net/bridge/br_private.h"
+BTF_KEEP(net_bridge, struct net_bridge);
+BTF_KEEP(net_bridge_port, struct net_bridge_port);
+#endif
+
+#if __has_include("fs/mount.h")
+#include "fs/mount.h"
+BTF_KEEP(mount, struct mount);
+#endif