From nobody Mon Oct 6 06:39:55 2025 Received: from out-182.mta0.migadu.com (out-182.mta0.migadu.com [91.218.175.182]) (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 BE2222E9ECA for ; Thu, 24 Jul 2025 15:15:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753370123; cv=none; b=PkwlKTsfL0gbldOrf6t3dUsjP6OvcWcfsASK9Y2yQMg8As+QLLFMjbcrSSEYh9l+4Ebt5CjpQjL0q6zrluX+uQfuANE4GSxUdm5ZsW+2LwUbh+YXoSDlaKOQnIZmdmj6OHGQt0rCDYIYJr3GdkHwiyX0OP+QvT9wyahFZC27oL8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753370123; c=relaxed/simple; bh=EOcAPAX1vQ4XIk2/UrVWTxL9MCVWE5oN9MT9W2II56I=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JF1N1ECE8IsPHheTthWvxRzMz8YZxn/6cYqDUhfy183PGA3wqA+oq7x4ZpHwO0GsfZDLLRIeES/6Xcr/PYiIxzmrjMyNIzXXcxlXAz61RYJCh67FZ96dgFpBr6QvonEJBdIF9LByeXojSm2uw2VA6NY/ixPt/dpM9R1LsMxzwIM= 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=A4798Up0; arc=none smtp.client-ip=91.218.175.182 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="A4798Up0" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1753370118; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ElR9Dd4bdnPHpZLYz3QLh/uZus9GLW0mgy218VPlreM=; b=A4798Up0BsBRUIgT7YPu1ixF9//13jLsBK4Y5pNRMwPKvbMj7qRSx8FNQ+w4Z4G/eb8LqQ sigTBLrPYKGJ4/VOkhEl7oJJucqgYPaDuP96d3utXvj1PcnkvrgtrmL2ppaqlkUQIkRBz9 iZWZNTfmDzOmtOsh60GS7n7OzlPm1OQ= From: KaFai Wan To: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, mykolal@fb.com, shuah@kernel.org, kafai.wan@linux.dev, laoar.shao@gmail.com, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, leon.hwang@linux.dev Subject: [PATCH bpf-next v4 1/4] bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions Date: Thu, 24 Jul 2025 23:14:51 +0800 Message-ID: <20250724151454.499040-2-kafai.wan@linux.dev> In-Reply-To: <20250724151454.499040-1-kafai.wan@linux.dev> References: <20250724151454.499040-1-kafai.wan@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" With this change, we know the precise rejected function name when attaching fexit/fmod_ret to __noreturn functions from log. $ ./fexit libbpf: prog 'fexit': BPF program load failed: -EINVAL libbpf: prog 'fexit': -- BEGIN PROG LOAD LOG -- Attaching fexit/fmod_ret to __noreturn function 'do_exit' is rejected. Suggested-by: Leon Hwang Signed-off-by: KaFai Wan Acked-by: Yafang Shao Acked-by: Yonghong Song --- kernel/bpf/verifier.c | 3 ++- tools/testing/selftests/bpf/progs/fexit_noreturns.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index e2fcea860755..00d287814f12 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -23946,7 +23946,8 @@ static int check_attach_btf_id(struct bpf_verifier_= env *env) } else if ((prog->expected_attach_type =3D=3D BPF_TRACE_FEXIT || prog->expected_attach_type =3D=3D BPF_MODIFY_RETURN) && btf_id_set_contains(&noreturn_deny, btf_id)) { - verbose(env, "Attaching fexit/fmod_ret to __noreturn functions is reject= ed.\n"); + verbose(env, "Attaching fexit/fmod_ret to __noreturn function '%s' is re= jected.\n", + tgt_info.tgt_name); return -EINVAL; } =20 diff --git a/tools/testing/selftests/bpf/progs/fexit_noreturns.c b/tools/te= sting/selftests/bpf/progs/fexit_noreturns.c index 54654539f550..b1c33d958ae2 100644 --- a/tools/testing/selftests/bpf/progs/fexit_noreturns.c +++ b/tools/testing/selftests/bpf/progs/fexit_noreturns.c @@ -8,7 +8,7 @@ char _license[] SEC("license") =3D "GPL"; =20 SEC("fexit/do_exit") -__failure __msg("Attaching fexit/fmod_ret to __noreturn functions is rejec= ted.") +__failure __msg("Attaching fexit/fmod_ret to __noreturn function 'do_exit'= is rejected.") int BPF_PROG(noreturns) { return 0; --=20 2.43.0