Use bazel to build ebpf parts

bazel/rules/ebpf.bzl

@@ -0,0 +1,264 @@
+"""Bazel rules for compiling eBPF programs (.c -> .bc -> .o)."""
+
+load("@linux_headers//:defs.bzl", "KERNEL_ARCH", "KERNEL_HEADER_DIRS")
+load("@rules_cc//cc/common:cc_info.bzl", "CcInfo")
+
+_TOOLCHAIN_TYPE = "@@//bazel/toolchains/llvm_bpf:llvm_bpf_toolchain_type"
+
+_ARCH_DEFINES = {
+    "x86_64": ["-D__TARGET_ARCH_x86", "-D__x86_64__"],
+    "aarch64": ["-D__TARGET_ARCH_arm64", "-D__aarch64__"],
+}
+
+_COMMON_FLAGS = [
+    "-D__KERNEL__",
+    "-D__BPF_TRACING__",
+    '-DKBUILD_MODNAME="ddsysprobe"',
+    "-Wno-unused-value",
+    "-Wno-pointer-sign",
+    "-Wno-compare-distinct-pointer-types",
+    "-Wunused",
+    "-Wall",
+    "-Werror",
+    "-O2",
+    "-fno-stack-protector",
+    "-fno-color-diagnostics",
+    "-fno-unwind-tables",
+    "-fno-asynchronous-unwind-tables",
+    "-fno-jump-tables",
+    "-fmerge-all-constants",
+]
+
+_PREBUILT_FLAGS = [
+    "-DCONFIG_64BIT",
+    "-DCOMPILE_PREBUILT",
+]
+
+_CORE_FLAGS = [
+    "-DCOMPILE_CORE",
+    "-g",
+]
+
+def _get_arch_flags(target_arch):
+    """Get architecture-specific defines."""
+    if target_arch:
+        return _ARCH_DEFINES.get(target_arch, [])
+
+    # Default from detected kernel arch
+    if KERNEL_ARCH == "arm64":
+        return _ARCH_DEFINES.get("aarch64", [])
+    return _ARCH_DEFINES.get("x86_64", [])
+
+def _collect_includes(deps):
+    """Collect include directories from cc_library dependencies."""
+    dirs = []
+    for dep in deps:
+        if CcInfo in dep:
+            cc_info = dep[CcInfo]
+            for inc in cc_info.compilation_context.includes.to_list():
+                dirs.append(inc)
+            for inc in cc_info.compilation_context.system_includes.to_list():
+                dirs.append(inc)
+            for inc in cc_info.compilation_context.quote_includes.to_list():
+                dirs.append(inc)
+    return dirs
+
+def _collect_headers(deps):
+    """Collect header files from cc_library dependencies."""
+    hdrs = []
+    for dep in deps:
+        if CcInfo in dep:
+            cc_info = dep[CcInfo]
+            hdrs.append(cc_info.compilation_context.headers)
+    return depset(transitive = hdrs)
+
+def _ebpf_prog_impl(ctx):
+    tc = ctx.toolchains[_TOOLCHAIN_TYPE].llvm_bpf
+    if not tc.valid:
+        fail("LLVM BPF toolchain is not available")
+
+    src = ctx.file.src
+    include_dirs = _collect_includes(ctx.attr.deps)
+    header_files = _collect_headers(ctx.attr.deps)
+
+    # Build flags
+    flags = list(_COMMON_FLAGS)
+
+    if ctx.attr.core:
+        flags.extend(_CORE_FLAGS)
+    else:
+        flags.extend(_PREBUILT_FLAGS)
+        flags.extend(["-include", "pkg/ebpf/c/asm_goto_workaround.h"])
+
+    # Architecture defines
+    flags.extend(_get_arch_flags(ctx.attr.target_arch))
+
+    if ctx.attr.debug:
+        flags.append("-DDEBUG=1")
+
+    flags.extend(ctx.attr.extra_flags)
+
+    # --- Step 1: .c -> .bc (clang) ---
+    bc_file = ctx.actions.declare_file(ctx.label.name + ".bc")
+
+    clang_args = ctx.actions.args()
+    if ctx.attr.core:
+        clang_args.add("-target", "bpf")
+    clang_args.add("-emit-llvm")
+    clang_args.add_all(flags)
+
+    # Include directories from deps
+    for d in include_dirs:
+        clang_args.add("-I", d)
+
+    # Kernel headers for prebuilt programs
+    kernel_header_inputs = []
+    if not ctx.attr.core and KERNEL_HEADER_DIRS:
+        kernel_header_files = ctx.files._linux_headers
+        kernel_header_inputs = kernel_header_files
+
+        # Resolve the external repo root from a file path.
+        # Files are at external/<repo>/kernel_N/include/..., we need
+        # the prefix up to (not including) "kernel_".
+        if kernel_header_files:
+            sample = kernel_header_files[0].path
+            idx = sample.find("/kernel_")
+            repo_root = sample[:idx] if idx >= 0 else sample.rsplit("/", 1)[0]
+            for d in KERNEL_HEADER_DIRS:
+                clang_args.add("-isystem", repo_root + "/" + d)
+
+    clang_args.add("-c", src)
+    clang_args.add("-o", bc_file)
+
+    ctx.actions.run(
+        inputs = depset(
+            [src] + kernel_header_inputs,
+            transitive = [header_files],
+        ),
+        outputs = [bc_file],
+        executable = tc.clang_bpf,
+        arguments = [clang_args],
+        mnemonic = "EbpfClang",
+        progress_message = "Compiling eBPF %{label} (.c -> .bc)",
+    )
+
+    # --- Step 2: .bc -> .o (llc) ---
+    obj_file = ctx.actions.declare_file(ctx.label.name + ".o")
+
+    llc_args = ctx.actions.args()
+    llc_args.add("-march=bpf")
+    llc_args.add("-filetype=obj")
+    llc_args.add("-o", obj_file)
+    llc_args.add(bc_file)
+
+    ctx.actions.run(
+        inputs = [bc_file],
+        outputs = [obj_file],
+        executable = tc.llc_bpf,
+        arguments = [llc_args],
+        mnemonic = "EbpfLlc",
+        progress_message = "Linking eBPF %{label} (.bc -> .o)",
+    )
+
+    return [DefaultInfo(files = depset([obj_file]))]
+
+_ebpf_prog = rule(
+    implementation = _ebpf_prog_impl,
+    attrs = {
+        "src": attr.label(
+            mandatory = True,
+            allow_single_file = [".c"],
+            doc = "The eBPF C source file.",
+        ),
+        "deps": attr.label_list(
+            providers = [CcInfo],
+            doc = "cc_library targets providing headers.",
+        ),
+        "core": attr.bool(
+            default = False,
+            doc = "CO-RE mode (no kernel headers, adds -DCOMPILE_CORE -g).",
+        ),
+        "debug": attr.bool(
+            default = False,
+            doc = "Include DEBUG=1 define.",
+        ),
+        "extra_flags": attr.string_list(
+            doc = "Additional compiler flags.",
+        ),
+        "target_arch": attr.string(
+            doc = "Target architecture: x86_64 or aarch64. Defaults to x86_64.",
+        ),
+        "_linux_headers": attr.label(
+            default = "@linux_headers//:all",
+            allow_files = True,
+        ),
+    },
+    toolchains = [_TOOLCHAIN_TYPE],
+)
+
+def _ebpf_prog_macro_impl(name, visibility, src, deps, core, debug, extra_flags, target_arch):
+    _ebpf_prog(
+        name = name,
+        visibility = visibility,
+        src = src,
+        deps = deps,
+        core = core,
+        debug = debug,
+        extra_flags = extra_flags,
+        target_arch = target_arch,
+        target_compatible_with = ["@platforms//os:linux"],
+    )
+
+ebpf_prog = macro(
+    doc = "Compile a single eBPF program (.c -> .o), Linux-only.",
+    attrs = {
+        "src": attr.label(mandatory = True, allow_single_file = [".c"], configurable = False),
+        "deps": attr.label_list(default = [], configurable = False),
+        "core": attr.bool(default = False, configurable = False),
+        "debug": attr.bool(default = False, configurable = False),
+        "extra_flags": attr.string_list(default = [], configurable = False),
+        "target_arch": attr.string(default = "", configurable = False),
+    },
+    implementation = _ebpf_prog_macro_impl,
+)
+
+def _ebpf_program_suite_impl(name, visibility, src, deps, core, extra_flags, target_arch):
+    _ebpf_prog(
+        name = name,
+        visibility = visibility,
+        src = src,
+        deps = deps,
+        core = core,
+        debug = False,
+        extra_flags = extra_flags,
+        target_arch = target_arch,
+        target_compatible_with = ["@platforms//os:linux"],
+    )
+    _ebpf_prog(
+        name = name + "-debug",
+        visibility = visibility,
+        src = src,
+        deps = deps,
+        core = core,
+        debug = True,
+        extra_flags = extra_flags,
+        target_arch = target_arch,
+        target_compatible_with = ["@platforms//os:linux"],
+    )
+
+ebpf_program_suite = macro(
+    doc = """Create both normal and debug variants of an eBPF program.
+
+    Generates:
+      - {name}: normal build
+      - {name}-debug: build with DEBUG=1
+    """,
+    attrs = {
+        "src": attr.label(mandatory = True, allow_single_file = [".c"], configurable = False),
+        "deps": attr.label_list(default = [], configurable = False),
+        "core": attr.bool(default = False, configurable = False),
+        "extra_flags": attr.string_list(default = [], configurable = False),
+        "target_arch": attr.string(default = "", configurable = False),
+    },
+    implementation = _ebpf_program_suite_impl,
+)

cmd/system-probe/subcommands/ebpf/testdata/BUILD.bazel

@@ -0,0 +1,12 @@
+load("//bazel/rules:ebpf.bzl", "ebpf_prog")
+
+ebpf_prog(
+    name = "btf_test",
+    src = "btf_test.c",
+    core = True,
+    extra_flags = [
+        "-g",
+        "-DDEBUG=1",
+    ],
+    deps = ["//pkg/ebpf/c:ebpf_c_headers"],
+)

pkg/collector/corechecks/ebpf/c/runtime/BUILD.bazel

@@ -0,0 +1,48 @@
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+load("//bazel/rules:ebpf.bzl", "ebpf_program_suite")
+
+cc_library(
+    name = "corecheck_ebpf_headers",
+    hdrs = glob(["*.h"]),
+    includes = ["."],
+)
+
+ebpf_program_suite(
+    name = "oom-kill",
+    src = "oom-kill-kern.c",
+    core = True,
+    deps = [
+        ":corecheck_ebpf_headers",
+        "//pkg/ebpf/c:ebpf_c_headers",
+    ],
+)
+
+ebpf_program_suite(
+    name = "tcp-queue-length",
+    src = "tcp-queue-length-kern.c",
+    core = True,
+    deps = [
+        ":corecheck_ebpf_headers",
+        "//pkg/ebpf/c:ebpf_c_headers",
+    ],
+)
+
+ebpf_program_suite(
+    name = "ebpf",
+    src = "ebpf-kern.c",
+    core = True,
+    deps = [
+        ":corecheck_ebpf_headers",
+        "//pkg/ebpf/c:ebpf_c_headers",
+    ],
+)
+
+ebpf_program_suite(
+    name = "noisy-neighbor",
+    src = "noisy-neighbor-kern.c",
+    core = True,
+    deps = [
+        ":corecheck_ebpf_headers",
+        "//pkg/ebpf/c:ebpf_c_headers",
+    ],
+)

pkg/dyninst/ebpf/BUILD.bazel

@@ -0,0 +1,35 @@
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+load("//bazel/rules:ebpf.bzl", "ebpf_prog")
+
+cc_library(
+    name = "dyninst_ebpf_headers",
+    hdrs = glob(["*.h"]),
+    includes = ["."],
+    visibility = ["//visibility:public"],
+)
+
+ebpf_prog(
+    name = "dyninst_event",
+    src = "event.c",
+    core = True,
+    extra_flags = ["-Ipkg/dyninst/ebpf"],
+    deps = [
+        ":dyninst_ebpf_headers",
+        "//pkg/ebpf/c:ebpf_c_headers",
+    ],
+)
+
+ebpf_prog(
+    name = "dyninst_event-debug",
+    src = "event.c",
+    core = True,
+    debug = True,
+    extra_flags = [
+        "-Ipkg/dyninst/ebpf",
+        "-DDYNINST_DEBUG=1",
+    ],
+    deps = [
+        ":dyninst_ebpf_headers",
+        "//pkg/ebpf/c:ebpf_c_headers",
+    ],
+)

pkg/ebpf/c/BUILD.bazel

@@ -0,0 +1,23 @@
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+load("//bazel/rules:ebpf.bzl", "ebpf_prog")
+
+cc_library(
+    name = "ebpf_c_headers",
+    hdrs = glob(["*.h"]),
+    includes = ["."],
+    visibility = ["//visibility:public"],
+)
+
+ebpf_prog(
+    name = "lock_contention",
+    src = "lock_contention.c",
+    core = True,
+    deps = [":ebpf_c_headers"],
+)
+
+ebpf_prog(
+    name = "ksyms_iter",
+    src = "ksyms_iter.c",
+    core = True,
+    deps = [":ebpf_c_headers"],
+)