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 A7779CCA47E for ; Tue, 14 Jun 2022 01:47:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347395AbiFNBrk (ORCPT ); Mon, 13 Jun 2022 21:47:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241377AbiFNBre (ORCPT ); Mon, 13 Jun 2022 21:47:34 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4236EF70 for ; Mon, 13 Jun 2022 18:47:28 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id a68-20020a25ca47000000b006605f788ff1so6378769ybg.16 for ; Mon, 13 Jun 2022 18:47:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=l4PjIvONm1IQKFepEMuDqPyve0EvuaStAKHleWOI5U4=; b=keMrD0lK99MmEmZqNHED9SqQIvx29ap+MgANfW658dwlfZvJrsoNWlI9FXDBxqa+za VARGdXXoJmn5KryQWZj+8ScXKK6VXqNwAmxBq3WrvJtTYqyF49pPQeabsvoQ33dd7Zm9 GUdC5cio7eBOfzPKl6VgquXY1jLeMHFBa0mblXnksXxjh9ZBheHBbS2YBLkmyB2cnv0z RODtwrbl065MJcM4aR2i0vB2oIgwB4RMKqps974SsAItXpR+hUM9whwp/5wZxzkdRDOz ZEJKu26kcTh5Mj7t2oGlCPJPuLSeewLtsuZoU0kfm6Fy8cQ92KsRwUtE31ZwuEw4o661 pfTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=l4PjIvONm1IQKFepEMuDqPyve0EvuaStAKHleWOI5U4=; b=JFOiZTMYRytOVrT7ANR0h0HlFzP0Y1OZjzoPSNFthlYWxO1zYhDCX5pMxZl9fQ84uf qdXbBJhwLxfbMPSY527dsFJLwi12UvrqVCAid849KbLar9KXNQwwYtN1x9DEtFwMsxuQ 7C0ChSx2M2nkICcWKz2wRBgrNEFyu8wgq97n/k+9477lHXfGjcKkqdTKFY4MzMiMkB6g WMfogIIHdi/xlCJQtzqbTF1K64ECM9L3+hQqNHn43rMrGitckLvrtsADPkidLvKQ7J/t PiQ8tCzB1JDIHnaP8215/HqLKDI5SJ4vWqIAVaTCoxYzxzc7UybOrbMcTZFXwGD5q3j/ 7VIw== X-Gm-Message-State: AJIora+TMiXBH6nUIdGznKhL7x66xdEkMILmljj5e35lbqGpv+DCN9JD RDQ6uTWSxuY09w36I8Afs+zQ1CP3nUnQ X-Google-Smtp-Source: AGRyM1subzJdwRtf+vAOstyD6tqNevSviIR17aL9d/daU5mnA6A1DY7dA9Gj0iqv9t7BAYwDQeVntF57tsLy X-Received: from irogers.svl.corp.google.com ([2620:15c:2cd:202:e4b4:1d0c:1c56:a7ed]) (user=irogers job=sendgmr) by 2002:a25:3c45:0:b0:664:cf75:c2d6 with SMTP id j66-20020a253c45000000b00664cf75c2d6mr2520288yba.446.1655171248020; Mon, 13 Jun 2022 18:47:28 -0700 (PDT) Date: Mon, 13 Jun 2022 18:47:14 -0700 Message-Id: <20220614014714.1407239-1-irogers@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.36.1.476.g0c4daa206d-goog Subject: [PATCH] perf bpf: 8 byte align bpil data From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Dave Marchevsky , Quentin Monnet , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org Cc: Stephane Eranian , Ian Rogers Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org bpil data is accessed assuming 64-bit alignment resulting in undefined behavior as the data is just byte aligned. With an -fsanitize=undefined build the following errors are observed: $ sudo perf record -a sleep 1 util/bpf-event.c:310:22: runtime error: load of misaligned address 0x55f61084520f for type '__u64', which requires 8 byte alignment 0x55f61084520f: note: pointer points here a8 fe ff ff 3c 51 d3 c0 ff ff ff ff 04 84 d3 c0 ff ff ff ff d8 aa d3 c0 ff ff ff ff a4 c0 d3 c0 ^ util/bpf-event.c:311:20: runtime error: load of misaligned address 0x55f61084522f for type '__u32', which requires 4 byte alignment 0x55f61084522f: note: pointer points here ff ff ff ff c7 17 00 00 f1 02 00 00 1f 04 00 00 58 04 00 00 00 00 00 00 0f 00 00 00 63 02 00 00 ^ util/bpf-event.c:198:33: runtime error: member access within misaligned address 0x55f61084523f for type 'const struct bpf_func_info', which requires 4 byte alignment 0x55f61084523f: note: pointer points here 58 04 00 00 00 00 00 00 0f 00 00 00 63 02 00 00 3b 00 00 00 ab 02 00 00 44 00 00 00 14 03 00 00 Correct this by rouding up the data sizes and aligning the pointers. Signed-off-by: Ian Rogers --- tools/perf/util/bpf-utils.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/bpf-utils.c b/tools/perf/util/bpf-utils.c index e271e05e51bc..80b1d2b3729b 100644 --- a/tools/perf/util/bpf-utils.c +++ b/tools/perf/util/bpf-utils.c @@ -149,11 +149,10 @@ get_bpf_prog_info_linear(int fd, __u64 arrays) count = bpf_prog_info_read_offset_u32(&info, desc->count_offset); size = bpf_prog_info_read_offset_u32(&info, desc->size_offset); - data_len += count * size; + data_len += roundup(count * size, sizeof(__u64)); } /* step 3: allocate continuous memory */ - data_len = roundup(data_len, sizeof(__u64)); info_linear = malloc(sizeof(struct perf_bpil) + data_len); if (!info_linear) return ERR_PTR(-ENOMEM); @@ -180,7 +179,7 @@ get_bpf_prog_info_linear(int fd, __u64 arrays) bpf_prog_info_set_offset_u64(&info_linear->info, desc->array_offset, ptr_to_u64(ptr)); - ptr += count * size; + ptr += roundup(count * size, sizeof(__u64)); } /* step 5: call syscall again to get required arrays */ -- 2.36.1.476.g0c4daa206d-goog