From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-186.mta0.migadu.com (out-186.mta0.migadu.com [91.218.175.186]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ABAF01F8755 for ; Wed, 8 Jul 2026 03:23:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.186 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783480990; cv=none; b=oY0lyci80HMaKjBEmOGSDLEKu5vhlisA32PiLl/GEf9Sdbz2VXqt2VhdUzedWT+FVpBQj+AaDZkTrInKx+CdLybkrAgNmQQ8lKgKQtKN7OV+b8cR3ChQ1jqdNX9fyBhFHKfFbD+srZXCRUxFWM+aODjCP0xYoPdvIYS76FpSQEM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783480990; c=relaxed/simple; bh=LR8ZkF3VK3DQ+1b3NahwIArIM/D2QpLWCJHiyLBsbcA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=HfjDoQccUY8Lc+NI4QwyTzDOQMpUsG6LZeaY0d3MsVR5ECo2IUUayeXUXBe2bBJYJKd7YFXiuMPfYZ+roTEcPLh2bkvER4fGAeWN8iwH3d6MmN6T5/v7Sn3WfSbPckO9w4cA/KkO0h1qBLXQLEbeW/dYixM6kA72O0euGgIHhw4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=lOC67acm; arc=none smtp.client-ip=91.218.175.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="lOC67acm" Message-ID: <2ea29553-b0bd-4d12-9ff9-9b6f99267fc0@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1783480976; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=y1a2UG4qiDNeOYHH404Fpdk2UN9XF1jE5+XaJZ48Ojg=; b=lOC67acmeaf3tcUhfAAiGGXM1A7NuahPyQs2Iqpm2I9o709r5Bl+5AZJILRy7VASo9jNQy nyBP76d6/n3pXWbVAXKatcYwgjSGewR+JmrUKwd0R7iKokj12CJUrnQHJht7Ijm98t6fTi TWpMHY8r43iaQweeu8Ho5Gb8XNUDr5Q= Date: Wed, 8 Jul 2026 11:22:44 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf 2/2] selftests/bpf: Add XDP dispatcher FineIBT regression test Content-Language: en-US To: David Windsor , bpf@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , "David S . Miller" , Jakub Kicinski , Jesper Dangaard Brouer , John Fastabend , Stanislav Fomichev , Shuah Khan , Peter Zijlstra , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org References: X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Leon Hwang In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 8/7/26 10:57, David Windsor wrote: > 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 > --- > .../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 > +#include > +#include > +#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 > +#include > + > +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"; Instead of creating xdp_dispatcher_fineibt.c, better to reuse xdp_dummy.c. Then, in xdp_dispatcher_fineibt.c, you can create two xdp_dummy skels, one for attaching, one for running. And, add the test to xdp_attach.c instead of new file prog_tests/xdp_dispatcher_fineibt.c? Thanks, Leon