Add a regression test for the x86 BPF dispatcher's indirect-jump fallback under FineIBT.
This test can crash the kernel on an unfixed FineIBT build and so should be run in a VM. Signed-off-by: David Windsor <[email protected]> --- .../bpf/prog_tests/xdp_dispatcher_fineibt.c | 47 +++++++++++++++++++ .../bpf/progs/xdp_dispatcher_fineibt.c | 18 +++++++ 2 files changed, 65 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_dispatcher_fineibt.c create mode 100644 tools/testing/selftests/bpf/progs/xdp_dispatcher_fineibt.c diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_dispatcher_fineibt.c b/tools/testing/selftests/bpf/prog_tests/xdp_dispatcher_fineibt.c new file mode 100644 index 000000000000..2d3fc4034eb9 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/xdp_dispatcher_fineibt.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2026 David Windsor */ + +/* + * Regression test for the x86 BPF dispatcher's indirect-jump fallback + * under FineIBT. + * + * WARNING + * ------- + * This test can crash the kernel, thus should be run in a VM. + */ +#include <uapi/linux/if_link.h> +#include <test_progs.h> +#include <network_helpers.h> +#include "xdp_dispatcher_fineibt.skel.h" + +#define IFINDEX_LO 1 + +void test_xdp_dispatcher_fineibt(void) +{ + struct xdp_dispatcher_fineibt *skel; + int err, attached_fd, unattached_fd; + + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + ); + + skel = xdp_dispatcher_fineibt__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open_and_load")) + return; + + attached_fd = bpf_program__fd(skel->progs.xdp_dispatcher_attached); + unattached_fd = bpf_program__fd(skel->progs.xdp_dispatcher_unattached); + + err = bpf_xdp_attach(IFINDEX_LO, attached_fd, XDP_FLAGS_SKB_MODE, NULL); + if (!ASSERT_OK(err, "attach_prog")) + goto out; + + err = bpf_prog_test_run_opts(unattached_fd, &topts); + ASSERT_OK(err, "unattached_test_run"); + ASSERT_EQ(topts.retval, XDP_PASS, "unattached_retval"); + + bpf_xdp_detach(IFINDEX_LO, XDP_FLAGS_SKB_MODE, NULL); +out: + xdp_dispatcher_fineibt__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/xdp_dispatcher_fineibt.c b/tools/testing/selftests/bpf/progs/xdp_dispatcher_fineibt.c new file mode 100644 index 000000000000..b49b84f01c8e --- /dev/null +++ b/tools/testing/selftests/bpf/progs/xdp_dispatcher_fineibt.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2026 David Windsor */ +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> + +SEC("xdp") +int xdp_dispatcher_attached(struct xdp_md *ctx) +{ + return XDP_PASS; +} + +SEC("xdp") +int xdp_dispatcher_unattached(struct xdp_md *ctx) +{ + return XDP_PASS; +} + +char _license[] SEC("license") = "GPL"; -- 2.53.0
