Reproducer for iovisor/bcc#4890

bisect.sh

#!/bin/bash
set -eEuxo pipefail

export PATH="$HOME/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
export LD_LIBRARY_PATH="$HOME/.local/lib64"

trap 'exit -1' ERR

pushd "$HOME/llvm-project"
rm -r ./build || true
if ! grep -e 'include <cstdint>' 'llvm/include/llvm/Support/Signals.h'; then
	git cherry-pick \
		--no-commit \
		--keep-redundant-commits \
		ff1681ddb303223973653f7f5f3f3435b48a1983
fi
if ! grep -e 'include <limits>' 'llvm/utils/benchmark/src/benchmark_register.h'; then
	git cherry-pick \
		--no-commit \
		--keep-redundant-commits \
		b498303066a63a203d24f739b2d2e0e56dca70d1
fi
if ! grep -e 'include <cstdint>' 'llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h'; then
	git cherry-pick \
		--no-commit \
		--keep-redundant-commits \
		b288d90b39f4b905c02092a9bfcfd6d78f99b191
fi
cmake -S llvm -B build -G Ninja -Wno-dev \
	-DCMAKE_BUILD_TYPE=Release \
	-DLLVM_ENABLE_ASSERTIONS=OFF \
	-DLLVM_OPTIMIZED_TABLEGEN=ON \
	-DCMAKE_INSTALL_PREFIX="$HOME/.local" \
	-DLLVM_LIBDIR_SUFFIX=64 \
	-DLLVM_CCACHE_BUILD=ON \
	-DLLVM_CCACHE_MAXSIZE=60G \
	-DLLVM_BUILD_LLVM_DYLIB=ON \
	-DLLVM_LINK_LLVM_DYLIB=ON \
	-DBUILD_SHARED_LIBS=OFF \
	-DLLVM_ENABLE_PROJECTS=clang \
	-DLLVM_TARGETS_TO_BUILD='BPF' \
	-DLLVM_PARALLEL_LINK_JOBS=2
time ninja -C build
rm -r \
	~/.local/lib64/libLLVM* \
	~/.local/lib64/libclang* \
	~/.local/lib64/clang \
	~/.local/lib64/libLTO* || true
ninja -C build install
git reset --hard HEAD
popd

pushd "$HOME/bcc"
rm -r ./build || true
git submodule update
if ! grep -e 'collections.abc' 'src/python/bcc/table.py'; then
	git cherry-pick \
		--no-commit \
		--keep-redundant-commits \
		--rerere-autoupdate \
		48946d2f31afbfb7b4bc7c62a9d3d6f1d2ffc330
fi
LLVM_ROOT='/home/user/.local/bin/llvm-' cmake -B build -Wno-dev \
	-DCMAKE_MODULE_PATH='/home/user/.local/lib64/cmake' \
	-DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
	-DCMAKE_C_COMPILER_LAUNCHER=ccache \
	-DLLVM_LIBRARY_DIRS='/home/user/.local/lib64' \
	-DREVISION="$(git describe --tags HEAD | sed 's/^v//' | sed 's/-.*$//')" \
	-DPYTHON_CMD=python3 \
	-DCMAKE_INSTALL_PREFIX="$HOME/.local" \
	-DENABLE_LLVM_SHARED=1 \
	-DLUAJIT_INCLUDE_DIR=`pkg-config --variable=includedir luajit` \
	-DLUAJIT_LIBRARY=/usr/lib64/lib`pkg-config --variable=libname luajit`.so \
	-DENABLE_NO_PIE=OFF \
	-DRUN_LUA_TESTS=OFF \
	-DENABLE_TESTS=OFF \
	-DENABLE_USDT=ON
time make -C build -j$(nproc)
rm -r \
	~/.local/lib64/libbcc* \
	~/.local/lib/python3.11/site-packages/bcc* || true
make -C build install
git reset --hard HEAD
popd

pushd "$HOME"
if (~/bitfield_test.py 2>&1 || true) | grep -e ' = 32'; then
	echo "Has bug"
	exit 1
else
	echo "NO bug"
	exit 0
fi
popd

bitfield_test.py

#!/usr/bin/env python3

import bcc
from bcc import BPF
import sys

bpf_text = """

#include <uapi/linux/ptrace.h>

struct event_t {
    long offset1;
    long offset2;
};
BPF_PERF_OUTPUT(events);


struct sk_buff;

struct my_struct
{
    long: 64;
    long: 64;
    long: 64;
    void* ptr;
};

int kprobe__netif_rx(struct pt_regs *ctx)
{
    struct event_t event = {};
    void* p1 = (void*)ctx->di;
    void* p2 = NULL;

    event.offset1 = ((long)&((struct my_struct*)p1)->ptr) - (long)p1;
    event.offset2 = ((long)&((struct my_struct*)p2)->ptr) - (long)p2;
    events.perf_submit(ctx, &event, sizeof(event));
    return 0;
}
"""

def print_event(cpu, data, size):
    event = b["events"].event(data)
    print(f"offset1: {event.offset1}")
    print(f"offset2: {event.offset2}")
    sys.exit(0)

b = BPF(text=bpf_text, debug=bcc.DEBUG_SOURCE | bcc.DEBUG_LLVM_IR | bcc.DEBUG_BTF | bcc.DEBUG_PREPROCESSOR)
b["events"].open_perf_buffer(print_event)

while 1:
    try:
        b.perf_buffer_poll()
    except KeyboardInterrupt:
        exit()