From patchwork Thu Sep 5 07:56:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Philo Lu X-Patchwork-Id: 13791900 Received: from out30-97.freemail.mail.aliyun.com (out30-97.freemail.mail.aliyun.com [115.124.30.97]) (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 5EB58193422; Thu, 5 Sep 2024 07:56:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.97 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725522994; cv=none; b=FyNzgx3fAx6Q7qYJFzHiyITT2Nwf60Rgm9fjrpPad9swV3pNJkYdd5p6raHaTfLzX+ZmmIS3TB+Pw6DJYky+fYc0cKQfztLjsGiUI1WMxA54nL+Utjm6BNYtB0IKsYVxcv4jQaCfNNqC8U0seS/5IGAOjvnu0xeYXa6vtzvTE9o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725522994; c=relaxed/simple; bh=9nX5BEqo/bJuVUV4T906+zK42dyZFMxqoxbNcOlRtAU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=drijcX7jjSCbfnr+4yDm4RQDvphP0AFhmBXfXSHmlzYWv9tFADbu0NxvxRb4d2ZWCU//hG1ZqPXQsGU908Bkx2lrCRGn0NKg9GK9FQ/CewGKyldMnASu2o7FSjBBpoMfSp/5Xbvl4isgjl3U9gCsnpoZM8KrELuhQC2LcRbvp9Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=SM4dkg2w; arc=none smtp.client-ip=115.124.30.97 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="SM4dkg2w" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1725522990; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=heg5ujh9995FGb5Bxbbr9bVFNtt01S491isl+3eyVds=; b=SM4dkg2wDBVCtiM81sxkeUyOD1h+8jkHwb4OF48R0mRF7dCAjNGwFKrmb3MczM2S3eSBy5aQfCrx0Mc7peP4M1XcKd/N4lTFYHs5ULndurGNcY0/SNfNLbALwaCXCKe9BioxGXZ7yxHNU5SNwpuS2vUVnFfrLpNAK+aQ/uncZ44= Received: from localhost(mailfrom:lulie@linux.alibaba.com fp:SMTPD_---0WEKuTDv_1725522987) by smtp.aliyun-inc.com; Thu, 05 Sep 2024 15:56:28 +0800 From: Philo Lu To: bpf@vger.kernel.org Cc: edumazet@google.com, rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, martin.lau@linux.dev, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, mykolal@fb.com, shuah@kernel.org, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, thinker.li@gmail.com, juntong.deng@outlook.com, jrife@google.com, alan.maguire@oracle.com, davemarchevsky@fb.com, dxu@dxuuu.xyz, vmalik@redhat.com, cupertino.miranda@oracle.com, mattbobrowski@google.com, xuanzhuo@linux.alibaba.com, netdev@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH bpf-next v2 4/5] bpf: Allow bpf_dynptr_from_skb() for tp_btf Date: Thu, 5 Sep 2024 15:56:21 +0800 Message-Id: <20240905075622.66819-5-lulie@linux.alibaba.com> X-Mailer: git-send-email 2.32.0.3.g01195cf9f In-Reply-To: <20240905075622.66819-1-lulie@linux.alibaba.com> References: <20240905075622.66819-1-lulie@linux.alibaba.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Making tp_btf able to use bpf_dynptr_from_skb(), which is useful for skb parsing, especially for non-linear paged skb data. This is achieved by adding KF_TRUSTED_ARGS flag to bpf_dynptr_from_skb and registering it for TRACING progs. With KF_TRUSTED_ARGS, args from fentry/fexit are excluded, so that unsafe progs like fexit/__kfree_skb are not allowed. We also need the skb dynptr to be read-only in tp_btf. Because may_access_direct_pkt_data() returns false by default when checking bpf_dynptr_from_skb, there is no need to add BPF_PROG_TYPE_TRACING to it explicitly. Suggested-by: Martin KaFai Lau Signed-off-by: Philo Lu Acked-by: Martin KaFai Lau --- net/core/filter.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/core/filter.c b/net/core/filter.c index 6d4fa9198b652..4c01f4756ddb5 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -12074,7 +12074,7 @@ int bpf_dynptr_from_skb_rdonly(struct __sk_buff *skb, u64 flags, } BTF_KFUNCS_START(bpf_kfunc_check_set_skb) -BTF_ID_FLAGS(func, bpf_dynptr_from_skb) +BTF_ID_FLAGS(func, bpf_dynptr_from_skb, KF_TRUSTED_ARGS) BTF_KFUNCS_END(bpf_kfunc_check_set_skb) BTF_KFUNCS_START(bpf_kfunc_check_set_xdp) @@ -12123,6 +12123,7 @@ static int __init bpf_kfunc_init(void) ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_XMIT, &bpf_kfunc_set_skb); ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_SEG6LOCAL, &bpf_kfunc_set_skb); ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_NETFILTER, &bpf_kfunc_set_skb); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &bpf_kfunc_set_skb); ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &bpf_kfunc_set_xdp); ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SOCK_ADDR, &bpf_kfunc_set_sock_addr);