From patchwork Wed May 18 13:16:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xu Kuohai X-Patchwork-Id: 12853710 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CD495C433EF for ; Wed, 18 May 2022 13:55:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=kiPd2ayp+2f6qTbVZLmdoUEsuKMiDnFdWEEhkcTemPI=; b=cijMlfgDs4K7eT HQXICZDf6uLH/NzOu1pfm2abgC7OeASpg+iGWjYBuAqsK1wlfWFoP61nujbceS6FdRU+yVvd4spz6 iXB5JPsV2Q6CLr3cTqjSDdO+igHO499hTiQ/zKfVnsyTu0XGNceyXRta/oNVLypj2cUWDm+4Kbfoa u4wcyIY74tPgANE9Z2TxH9jLvEo/txO7xoS5uqxvFZhADnN3/7YXrK9ynGIwzjY8Uuz77wCosiJTT Tr+uiQ7OH8Muu/Jn7x9FlA1+sFm4pYlhK+iFL4eNxCKuXfV+gaq6xoyA/ikAObo12+hUIlHtM3SG9 YImUIRZPb/X+Ufuivalw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nrK8X-002NlF-U0; Wed, 18 May 2022 13:54:50 +0000 Received: from szxga01-in.huawei.com ([45.249.212.187]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nrK7l-002NFT-5S for linux-arm-kernel@lists.infradead.org; Wed, 18 May 2022 13:54:03 +0000 Received: from kwepemi500013.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4L3DvQ22QxzgYBG; Wed, 18 May 2022 21:52:34 +0800 (CST) Received: from huawei.com (10.67.174.197) by kwepemi500013.china.huawei.com (7.221.188.120) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 18 May 2022 21:53:55 +0800 From: Xu Kuohai To: , , , , CC: Catalin Marinas , Will Deacon , Steven Rostedt , Ingo Molnar , Daniel Borkmann , Alexei Starovoitov , Zi Shen Lim , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , "David S . Miller" , Hideaki YOSHIFUJI , David Ahern , Thomas Gleixner , Borislav Petkov , Dave Hansen , , , Shuah Khan , Jakub Kicinski , Jesper Dangaard Brouer , Mark Rutland , Pasha Tatashin , Ard Biesheuvel , Daniel Kiss , Steven Price , Sudeep Holla , Marc Zyngier , Peter Collingbourne , Mark Brown , Delyan Kratunov , Kumar Kartikeya Dwivedi Subject: [PATCH bpf-next v5 3/6] bpf: Remove is_valid_bpf_tramp_flags() Date: Wed, 18 May 2022 09:16:35 -0400 Message-ID: <20220518131638.3401509-4-xukuohai@huawei.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220518131638.3401509-1-xukuohai@huawei.com> References: <20220518131638.3401509-1-xukuohai@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.197] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemi500013.china.huawei.com (7.221.188.120) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220518_065401_691364_9C193C30 X-CRM114-Status: GOOD ( 14.98 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org BPF_TRAM_F_XXX flags are not used by user code and are almost constant at compile time, so run time validation is a bit overkill. Remove is_valid_bpf_tramp_flags() and add some usage comments. Signed-off-by: Xu Kuohai Acked-by: Song Liu --- arch/x86/net/bpf_jit_comp.c | 20 -------------------- kernel/bpf/bpf_struct_ops.c | 3 +++ kernel/bpf/trampoline.c | 3 +++ 3 files changed, 6 insertions(+), 20 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index a2b6d197c226..7698ef3b4821 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1922,23 +1922,6 @@ static int invoke_bpf_mod_ret(const struct btf_func_model *m, u8 **pprog, return 0; } -static bool is_valid_bpf_tramp_flags(unsigned int flags) -{ - if ((flags & BPF_TRAMP_F_RESTORE_REGS) && - (flags & BPF_TRAMP_F_SKIP_FRAME)) - return false; - - /* - * BPF_TRAMP_F_RET_FENTRY_RET is only used by bpf_struct_ops, - * and it must be used alone. - */ - if ((flags & BPF_TRAMP_F_RET_FENTRY_RET) && - (flags & ~BPF_TRAMP_F_RET_FENTRY_RET)) - return false; - - return true; -} - /* Example: * __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev); * its 'struct btf_func_model' will be nr_args=2 @@ -2017,9 +2000,6 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i if (nr_args > 6) return -ENOTSUPP; - if (!is_valid_bpf_tramp_flags(flags)) - return -EINVAL; - /* Generated trampoline stack layout: * * RBP + 8 [ return address ] diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c index d9a3c9207240..0572cc5aeb28 100644 --- a/kernel/bpf/bpf_struct_ops.c +++ b/kernel/bpf/bpf_struct_ops.c @@ -341,6 +341,9 @@ int bpf_struct_ops_prepare_trampoline(struct bpf_tramp_links *tlinks, tlinks[BPF_TRAMP_FENTRY].links[0] = link; tlinks[BPF_TRAMP_FENTRY].nr_links = 1; + /* BPF_TRAMP_F_RET_FENTRY_RET is only used by bpf_struct_ops, + * and it must be used alone. + */ flags = model->ret_size > 0 ? BPF_TRAMP_F_RET_FENTRY_RET : 0; return arch_prepare_bpf_trampoline(NULL, image, image_end, model, flags, tlinks, NULL); diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 93c7675f0c9e..bd3f2e673874 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -358,6 +358,9 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr) if (tlinks[BPF_TRAMP_FEXIT].nr_links || tlinks[BPF_TRAMP_MODIFY_RETURN].nr_links) + /* NOTE: BPF_TRAMP_F_RESTORE_REGS and BPF_TRAMP_F_SKIP_FRAME + * should not be set together. + */ flags = BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_SKIP_FRAME; if (ip_arg)