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 E2949C7EE37 for ; Tue, 6 Jun 2023 21:02:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239452AbjFFVCy (ORCPT ); Tue, 6 Jun 2023 17:02:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60422 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234369AbjFFVCw (ORCPT ); Tue, 6 Jun 2023 17:02:52 -0400 Received: from mail-ot1-x32d.google.com (mail-ot1-x32d.google.com [IPv6:2607:f8b0:4864:20::32d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D81BD1721 for ; Tue, 6 Jun 2023 14:02:50 -0700 (PDT) Received: by mail-ot1-x32d.google.com with SMTP id 46e09a7af769-6b29c972e00so582972a34.1 for ; Tue, 06 Jun 2023 14:02:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1686085370; x=1688677370; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=uq9Pr6DWUVzSXGxbV7e8ZoB8v64gECVHajz2KbgU84M=; b=nk0kQfUOYGxbA0ifjF5QUVXaAIW1vfVdix4AA/DsDLhQGISIr3M35kVaT8owahipaR 3m9J2cqxnwxTh9FUa8hsSrnl3w/TbwfUh+mRJyBGbzLyeAYff7NlkA8KwTK8Klz9xWt6 bNhZCW188kLCU7KIQK44G91iqHSL9TNfyCXMWbmZjS9csnXbTG25MLQ2mGtqxEozkY86 xbbBHG2t/JEnYl7K7gyQbij+7mbujoSf98exF9Mckp0YUoHK6OtKX7iBupMuijEt6Q+f 4IBYc9+Dqzh+n0oDt8ypG/W8nwu2afenNgRK+ACJnQ5yf7q/6NEmbCpz9rsqEA7DUh2a W3Tg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686085370; x=1688677370; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=uq9Pr6DWUVzSXGxbV7e8ZoB8v64gECVHajz2KbgU84M=; b=RFdu20CVylJvLjZyyXQDCanKhO8Xw7TCdvv84mD3r948k2kBLNHovNYkSVbfCviM5J 9az9TLYS/z3SLLdqc0lBgwYxrFxGj3kNUARAwevDAxfrZRzLTE0E2T8+ahqB7Mk1/hqY omLaoSuWpg5rBZeHEpYEzxIhKFcrgwwOnf2ykL2vTNvCbFcA930YXsZU3egnz0bsw+Y7 kvN9vpR/x22e2/PE3rIprubh0fAtPqV9/gZQwpLdoJSfPyR1z5kNw+n7Ov25bzyLBpwK u4BmGI9aWzzVk6Y0cLrVzJ3ZWGpJLqMUPolXMgvk8gbMn+RPjq76Vp2dpsKGwpM/Ayv1 RP/Q== X-Gm-Message-State: AC+VfDwPtwDLBoJTJzD9xHK5onYyV0BMjtLuxkSCSH4o5Nr/hKwtPYfs +nVh9CG7+LfBfihqXIRHwgbfcQ== X-Google-Smtp-Source: ACHHUZ7LYh5dG7aPOBJuFRUuEBk0WqeuseveTYM2K8wIaYAbGmx3y0eFWA1FPUJnp32LJJKABJh6Qw== X-Received: by 2002:a05:6358:c014:b0:129:b9f4:6d43 with SMTP id ez20-20020a056358c01400b00129b9f46d43mr773502rwb.30.1686085369822; Tue, 06 Jun 2023 14:02:49 -0700 (PDT) Received: from google.com ([2620:15c:2d1:203:e8d0:a79a:be71:c670]) by smtp.gmail.com with ESMTPSA id m4-20020a17090a71c400b0025671de4606sm2918pjs.4.2023.06.06.14.02.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Jun 2023 14:02:49 -0700 (PDT) Date: Tue, 6 Jun 2023 14:02:44 -0700 From: Nick Desaulniers To: Alexander Lobakin Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Maciej Fijalkowski , Song Liu , Kumar Kartikeya Dwivedi , bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, tpgxyz@gmail.com Subject: Re: [PATCH v2 bpf 03/11] bpftool: use a local bpf_perf_event_value to fix accessing its fields Message-ID: References: <20220421003152.339542-1-alobakin@pm.me> <20220421003152.339542-4-alobakin@pm.me> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220421003152.339542-4-alobakin@pm.me> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 21, 2022 at 12:39:04AM +0000, Alexander Lobakin wrote: > Fix the following error when building bpftool: > > CLANG profiler.bpf.o > CLANG pid_iter.bpf.o > skeleton/profiler.bpf.c:18:21: error: invalid application of 'sizeof' to an incomplete type 'struct bpf_perf_event_value' > __uint(value_size, sizeof(struct bpf_perf_event_value)); > ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_helpers.h:13:39: note: expanded from macro '__uint' > tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_helper_defs.h:7:8: note: forward declaration of 'struct bpf_perf_event_value' > struct bpf_perf_event_value; > ^ > > struct bpf_perf_event_value is being used in the kernel only when > CONFIG_BPF_EVENTS is enabled, so it misses a BTF entry then. > Define struct bpf_perf_event_value___local with the > `preserve_access_index` attribute inside the pid_iter BPF prog to > allow compiling on any configs. It is a full mirror of a UAPI > structure, so is compatible both with and w/o CO-RE. > bpf_perf_event_read_value() requires a pointer of the original type, > so a cast is needed. > Hi Alexander, What's the status of this series? I wasn't able to find a v3 on lore. We received a report that OpenMandriva is carrying around this patch. https://github.com/ClangBuiltLinux/linux/issues/1805. + Tomasz Tomasz, do you have more info which particular configs can reproduce this issue? Is this patch still necessary? > Fixes: 47c09d6a9f67 ("bpftool: Introduce "prog profile" command") > Suggested-by: Andrii Nakryiko > Signed-off-by: Alexander Lobakin > --- > tools/bpf/bpftool/skeleton/profiler.bpf.c | 27 ++++++++++++++--------- > 1 file changed, 17 insertions(+), 10 deletions(-) > > diff --git a/tools/bpf/bpftool/skeleton/profiler.bpf.c b/tools/bpf/bpftool/skeleton/profiler.bpf.c > index ce5b65e07ab1..2f80edc682f1 100644 > --- a/tools/bpf/bpftool/skeleton/profiler.bpf.c > +++ b/tools/bpf/bpftool/skeleton/profiler.bpf.c > @@ -4,6 +4,12 @@ > #include > #include > > +struct bpf_perf_event_value___local { > + __u64 counter; > + __u64 enabled; > + __u64 running; > +} __attribute__((preserve_access_index)); > + > /* map of perf event fds, num_cpu * num_metric entries */ > struct { > __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY); > @@ -15,14 +21,14 @@ struct { > struct { > __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); > __uint(key_size, sizeof(u32)); > - __uint(value_size, sizeof(struct bpf_perf_event_value)); > + __uint(value_size, sizeof(struct bpf_perf_event_value___local)); > } fentry_readings SEC(".maps"); > > /* accumulated readings */ > struct { > __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); > __uint(key_size, sizeof(u32)); > - __uint(value_size, sizeof(struct bpf_perf_event_value)); > + __uint(value_size, sizeof(struct bpf_perf_event_value___local)); > } accum_readings SEC(".maps"); > > /* sample counts, one per cpu */ > @@ -39,7 +45,7 @@ const volatile __u32 num_metric = 1; > SEC("fentry/XXX") > int BPF_PROG(fentry_XXX) > { > - struct bpf_perf_event_value *ptrs[MAX_NUM_MATRICS]; > + struct bpf_perf_event_value___local *ptrs[MAX_NUM_MATRICS]; > u32 key = bpf_get_smp_processor_id(); > u32 i; > > @@ -53,10 +59,10 @@ int BPF_PROG(fentry_XXX) > } > > for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++) { > - struct bpf_perf_event_value reading; > + struct bpf_perf_event_value___local reading; > int err; > > - err = bpf_perf_event_read_value(&events, key, &reading, > + err = bpf_perf_event_read_value(&events, key, (void *)&reading, > sizeof(reading)); > if (err) > return 0; > @@ -68,14 +74,14 @@ int BPF_PROG(fentry_XXX) > } > > static inline void > -fexit_update_maps(u32 id, struct bpf_perf_event_value *after) > +fexit_update_maps(u32 id, struct bpf_perf_event_value___local *after) > { > - struct bpf_perf_event_value *before, diff; > + struct bpf_perf_event_value___local *before, diff; > > before = bpf_map_lookup_elem(&fentry_readings, &id); > /* only account samples with a valid fentry_reading */ > if (before && before->counter) { > - struct bpf_perf_event_value *accum; > + struct bpf_perf_event_value___local *accum; > > diff.counter = after->counter - before->counter; > diff.enabled = after->enabled - before->enabled; > @@ -93,7 +99,7 @@ fexit_update_maps(u32 id, struct bpf_perf_event_value *after) > SEC("fexit/XXX") > int BPF_PROG(fexit_XXX) > { > - struct bpf_perf_event_value readings[MAX_NUM_MATRICS]; > + struct bpf_perf_event_value___local readings[MAX_NUM_MATRICS]; > u32 cpu = bpf_get_smp_processor_id(); > u32 i, zero = 0; > int err; > @@ -102,7 +108,8 @@ int BPF_PROG(fexit_XXX) > /* read all events before updating the maps, to reduce error */ > for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++) { > err = bpf_perf_event_read_value(&events, cpu + i * num_cpu, > - readings + i, sizeof(*readings)); > + (void *)(readings + i), > + sizeof(*readings)); > if (err) > return 0; > } > -- > 2.36.0 > >