From mboxrd@z Thu Jan 1 00:00:00 1970 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 20630C433F5 for ; Tue, 17 May 2022 15:55:02 +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:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=oeyMzhci7WNLXeSGheJhCMnX1OUaetQ6+Pc+g9Mt0Sc=; b=eJ6WndHIhmuAP8 zuzoaOGfFyRa96IazUx/I5re/mbgNVhpQUBfwrDyJmSjpKoLVahIObZeIYmZtnz7RcdX540KCh1o3 CBYDOOFLHCSYWWN8dCzpqvXaakQ/AcP+4d1cqHx0J/lsIpdZvAqOMYBQKVdaPFVBuT4/PQHsJ8qIq az8+KTnp2AoC/74sJpFgiLAs5dy2IACuNCvWMB/BEapdP+p29ZbxUirNMMt1cCgvtk6PZgBZUHUlA z9XMbC42ge6s4XdnrgLVcHyD8Z0Sgt6TiWoYLDhmqYSw8B4HrB1k65o3/ErPVQbILpn8VV84wyw0t +YLXXGaE3hpalqzaO6oA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nqzWJ-00Em5d-5I; Tue, 17 May 2022 15:53:59 +0000 Received: from mail-pg1-x52c.google.com ([2607:f8b0:4864:20::52c]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nqzWG-00Em4k-6N for linux-arm-kernel@lists.infradead.org; Tue, 17 May 2022 15:53:57 +0000 Received: by mail-pg1-x52c.google.com with SMTP id s68so766488pgb.13 for ; Tue, 17 May 2022 08:53:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=rmBZXjHGe6pjrZrcbSckkH/iPjlINFANkKf9gszWPYU=; b=mCL2WZQfUMWu4xy6yy7X1+ebSif5rAu/jKymgNsJYYzZFnA9ugCrwiihsPYjvzThIU DFn5Lk91C0tZGoeUNkgplThRXBMayt2xcmaeF/kI+0KvGVR+kIISN5RmRdDJqe7Oadm+ ApJfECbPyywghswoV+jBSpOdkrBps9EXktTRVf3Url5a8fO/0L7wfegdHmd2rnO/VKqr 5aIFJRbhhBTCl8CG9Fz4O9HHJKwwrK9Rxg2vuvpaHSd9SFQ95LPDBKs/Xs2D02Uy/oXT ZFn7YQQsYYxadnuLDDRi0dvdKAfQu/UzUbSJrsKeXA9Nrm8fbp9Bp3m1fdX1C87JU/JQ FXxw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=rmBZXjHGe6pjrZrcbSckkH/iPjlINFANkKf9gszWPYU=; b=glTnb/UV2Qxo3TGovjwkG8fGLWzrlUaFGpvy4FjBVVPFR0HcwR6KbmNpGXdh8hwLki B3RbLK0hNqRwi+ZFOPhFX/ceomIdxJH4a3FW4aruUGMlcSRm37SuW00qKoc3xAqh6j4Y lDD1+1jiZyEWE8CVc3xU69TjHwvMi/rvbbJXCO4x55WbRo/jmKyG/3GXH9MNFtiO+g9T CM2wWIBtLRvGChddvFPU6wbGZj/LMdC2AglF8TZfRhad6CyINoqIjOLPTrkuWAgmMWpi HfvIDKmeAodbOBK5avk7y4WxQB0H9ouLJ/8cncgT3H9/Ak8LjYnoS74Gkr51g8CWmYC6 XLEA== X-Gm-Message-State: AOAM532MvPNBrgjnfTlz+TZwzsYfO78Hp/C2sDZqoJUk5/AfKjijSs87 IBhDpm3OReEW6c5rOkZuGo0= X-Google-Smtp-Source: ABdhPJxrXCSmhatJuzbkg3Oy+emIhom0t5nAYkNpvRG00a6Wimvdurd952Xq+8TaFxwV35QJJRu07A== X-Received: by 2002:a63:8442:0:b0:3c6:4271:cad with SMTP id k63-20020a638442000000b003c642710cadmr20242021pgd.275.1652802834212; Tue, 17 May 2022 08:53:54 -0700 (PDT) Received: from MacBook-Pro.local ([2620:10d:c090:500::2:c22a]) by smtp.gmail.com with ESMTPSA id d14-20020a62f80e000000b0050dc76281fdsm6932pfh.215.2022.05.17.08.53.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 May 2022 08:53:53 -0700 (PDT) Date: Tue, 17 May 2022 08:53:49 -0700 From: Alexei Starovoitov To: Xu Kuohai Cc: bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, 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 , x86@kernel.org, hpa@zytor.com, 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: Re: [PATCH bpf-next v4 3/6] bpf: Move is_valid_bpf_tramp_flags() to the public trampoline code Message-ID: <20220517155349.4jk5oymnjvrasw2p@MacBook-Pro.local> References: <20220517071838.3366093-1-xukuohai@huawei.com> <20220517071838.3366093-4-xukuohai@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220517071838.3366093-4-xukuohai@huawei.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220517_085356_274551_20EFB9F5 X-CRM114-Status: GOOD ( 16.44 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, May 17, 2022 at 03:18:35AM -0400, Xu Kuohai wrote: > > +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; > +} > + > +int bpf_prepare_trampoline(struct bpf_tramp_image *tr, void *image, > + void *image_end, const struct btf_func_model *m, > + u32 flags, struct bpf_tramp_links *tlinks, > + void *orig_call) > +{ > + if (!is_valid_bpf_tramp_flags(flags)) > + return -EINVAL; > + > + return arch_prepare_bpf_trampoline(tr, image, image_end, m, flags, > + tlinks, orig_call); > +} It's an overkill to introduce a new helper function just to validate flags that almost compile time constants. The flags are not user supplied. Please move /* BPF_TRAMP_F_RET_FENTRY_RET is only used by bpf_struct_ops ... */ comment to bpf_struct_ops.c right before it calls arch_prepare_bpf_trampoline() And add a comment to trampoline.c saying that BPF_TRAMP_F_RESTORE_REGS and BPF_TRAMP_F_SKIP_FRAME should not be set together. We could add a warn_on there or in arch code, but feels like overkill. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel