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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10DECC433F5 for ; Sun, 6 Mar 2022 17:28:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233883AbiCFR3p (ORCPT ); Sun, 6 Mar 2022 12:29:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229445AbiCFR3o (ORCPT ); Sun, 6 Mar 2022 12:29:44 -0500 Received: from mail-wr1-x42b.google.com (mail-wr1-x42b.google.com [IPv6:2a00:1450:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 037CE2613C; Sun, 6 Mar 2022 09:28:52 -0800 (PST) Received: by mail-wr1-x42b.google.com with SMTP id i8so19909632wrr.8; Sun, 06 Mar 2022 09:28:51 -0800 (PST) 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=W4/OOhsYIUeVHmDM2SWsQOWi+B+oFhl/nI7c5RX4BKk=; b=k/G44Yt5DvmreJLgQI3GuAgC3wsb0j+ZJByjP5drkWfERt+YNmstc2W0TTfGm1HxVS 3G2VKahdAIEqjtFVK8rujNynCstafulKqH5XtTZLRa2c6jHvSy8v2dPBRKV6QQXkYQ3t HKbY5GdjOKvLFJVrFe6Efa+7pU/nGCOYrS7KHCVzgfmswKjplqS6URV2g8GGrcLa9zpj R7IQevo1KkJxzjSkaeFTWrL3zhA4t4U08BGo4Gc6FJ0b7JMOQaFifVg2IloQy25BDbNa 40z9Fq8Ra6Lwt3zV74EBEpiLTaDUjePKwn647y5A4ALQb/qSEJxVN1/E7tOCd2ZcgRPC GJfQ== 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=W4/OOhsYIUeVHmDM2SWsQOWi+B+oFhl/nI7c5RX4BKk=; b=pj0MLWLtI54fvuJ6xwrH1x86zH3Rc2ikwlve36eTh8H1dCNfRRZt9bSH1jQlZBC5pu 39ptICXuOu0PCcskP88zzO+ib2mCKlHnV2K8UnlAtr/8lT9cj88mARKAbbNtdLMlRSFM iUM9G4p9olUOBLT5S9by7snOeIEFrbxS9Na2LYPQRz8pRozhpCi/kexSoVA82rkkZODI QuxW4ZcFgNmwwuZZm+RvmNcYPGQg7BL/5SyKv+FvqrN1tr0SK0GNPVKJ0cNlWxZsHo/V sKmXRYASmOXx0tvpCj1Fc7x76KN2mGwMwV7yiyPz4VJk8FBRbZ6cUSwTZUhOnptlUZEb HPBQ== X-Gm-Message-State: AOAM533P2h4T3ZOCKW3B4UBEiq4H743RfIrIBt9YDZcLzEYHcZSZtlws 8ksB33O5nLuZb18XCE1aN7o= X-Google-Smtp-Source: ABdhPJy6IOIefZKEVLH85QOwAx1WyN/ui30/FZc13mqplCcQ42ZblD13664bXrW0hVvc2oia4b/ALg== X-Received: by 2002:a5d:648f:0:b0:1f0:567b:5619 with SMTP id o15-20020a5d648f000000b001f0567b5619mr5581201wri.66.1646587730449; Sun, 06 Mar 2022 09:28:50 -0800 (PST) Received: from krava ([193.85.244.190]) by smtp.gmail.com with ESMTPSA id l5-20020a5d6745000000b001f1e4e40e42sm3504346wrw.77.2022.03.06.09.28.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 06 Mar 2022 09:28:50 -0800 (PST) Date: Sun, 6 Mar 2022 18:28:47 +0100 From: Jiri Olsa To: Andrii Nakryiko Cc: Jiri Olsa , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Masami Hiramatsu , Networking , bpf , lkml , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Steven Rostedt Subject: Re: [PATCH 02/10] bpf: Add multi kprobe link Message-ID: References: <20220222170600.611515-1-jolsa@kernel.org> <20220222170600.611515-3-jolsa@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Mar 04, 2022 at 03:11:01PM -0800, Andrii Nakryiko wrote: SNIP > > +static int > > +kprobe_multi_resolve_syms(const void *usyms, u32 cnt, > > + unsigned long *addrs) > > +{ > > + unsigned long addr, size; > > + const char **syms; > > + int err = -ENOMEM; > > + unsigned int i; > > + char *func; > > + > > + size = cnt * sizeof(*syms); > > + syms = kvzalloc(size, GFP_KERNEL); > > + if (!syms) > > + return -ENOMEM; > > + > > + func = kmalloc(KSYM_NAME_LEN, GFP_KERNEL); > > + if (!func) > > + goto error; > > + > > + if (copy_from_user(syms, usyms, size)) { > > + err = -EFAULT; > > + goto error; > > + } > > + > > + for (i = 0; i < cnt; i++) { > > + err = strncpy_from_user(func, syms[i], KSYM_NAME_LEN); > > + if (err == KSYM_NAME_LEN) > > + err = -E2BIG; > > + if (err < 0) > > + goto error; > > + > > + err = -EINVAL; > > + if (func[0] == '\0') > > + goto error; > > wouldn't empty string be handled by kallsyms_lookup_name? it would scan and compare all symbols with empty string, so it's better to test for it jirka > > > + addr = kallsyms_lookup_name(func); > > + if (!addr) > > + goto error; > > + if (!kallsyms_lookup_size_offset(addr, &size, NULL)) > > + size = MCOUNT_INSN_SIZE; > > + addr = ftrace_location_range(addr, addr + size - 1); > > + if (!addr) > > + goto error; > > + addrs[i] = addr; > > + } > > + > > + err = 0; > > +error: > > + kvfree(syms); > > + kfree(func); > > + return err; > > +} > > + > > [...]