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 7BC81C433EF for ; Mon, 18 Jul 2022 16:26:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233838AbiGRQZm (ORCPT ); Mon, 18 Jul 2022 12:25:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56802 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235852AbiGRQZc (ORCPT ); Mon, 18 Jul 2022 12:25:32 -0400 Received: from mail-yw1-x1133.google.com (mail-yw1-x1133.google.com [IPv6:2607:f8b0:4864:20::1133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 111282AC55 for ; Mon, 18 Jul 2022 09:25:30 -0700 (PDT) Received: by mail-yw1-x1133.google.com with SMTP id 00721157ae682-2ef5380669cso112952707b3.9 for ; Mon, 18 Jul 2022 09:25:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=mime-version:from:date:message-id:subject:to:cc; bh=VpWGg1Z0ItsY17Q4CdwHYBm/NTXahJiG/W0stWad/2Q=; b=n5EUgG9sYycF9rx9k+w17mzIJ3Pj6DrYXTIL5aEPlPpTtjjOdf1l8Igp1lz1jIDJ5u cA2DPALvySRgupdWKOc0onDRiwTQpFXEKgqJDhyTwzaVpWAXlAfpjVEueUBZTNKFyJy4 6Nf1q/swRCZ7WE6Z5w3uLnq41J/Q8eviEAMCc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=VpWGg1Z0ItsY17Q4CdwHYBm/NTXahJiG/W0stWad/2Q=; b=vBqrUIH8kb5xMzQjJPdDfdXBX3lQelL9VX+gmQj9thS0/ut26SRLxbLqKDyBAyC7Dh UHfg+B2TmSxNZZnw3T/nEKHiNWbLPeCTkUqSZY6R5QID20gdJ3busY3D13EBS6k8JQFn G4Pkpu3MX6wmIN6sRsj4OhxlqZSD2KMCgOw2wYpQDT+Xevz0bAeqp2SE76khRD+2IqFI r5vHiQj7bplFHhlcTnz+RlUCMsv7IrDCk0/A85wez4OxiNDB9nYj2NhH6uBoPny8EqiV lcDHn25qNJiHzbDLeIyYR5AOv3RCUMkW2yzILt393PpxkPY4emXUxOwyQRPkV9icpB2J oVmg== X-Gm-Message-State: AJIora9JsacTvMHOggQ1JM/+x8KdOlKYuwGagbbrTxNu7/SyfEEKXYlV ArfBiJizcNdLEgjwJjxDbBNLtkbHu9n3ahDv7hLonA== X-Google-Smtp-Source: AGRyM1vuHM0SfTPb0F/nlCzubE/m1n8j9K1rxYega5fLB3kYc9RJ9h5UWn69E2l7QS82ZzuOj6oMP6Brl3rTdOaLqQM= X-Received: by 2002:a81:1b15:0:b0:31d:f87f:7ab5 with SMTP id b21-20020a811b15000000b0031df87f7ab5mr17976514ywb.104.1658161529300; Mon, 18 Jul 2022 09:25:29 -0700 (PDT) MIME-Version: 1.0 From: Ivan Babrou Date: Mon, 18 Jul 2022 09:25:18 -0700 Message-ID: Subject: Removal of 128MB limit for BPF JIT programs broke perf symbolication on aarch64 To: Russell King Cc: Ard Biesheuvel , Daniel Borkmann , Alan Maguire , kernel-team , bpf , linux-perf-users@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Hello, We noticed that perf symbolication is broken on aarch64: ivan@vm:~$ sudo perf_5.10 record -e cpu-clock --cpu 3 -g --call-graph dwarf -F 11 -- sleep 0.1 ivan@vm:~$ sudo perf_5.10 script swapper 0 [003] 75.516009: 90909090 cpu-clock: ffffffe7fe311808 [unknown] ([unknown]) ffffffe7fdaf0a60 [unknown] ([unknown]) ffffffe7fdaf0bdc [unknown] ([unknown]) ffffffe7fda29538 [unknown] ([unknown]) ffffffe7fe3253b8 [unknown] ([unknown]) On Linux 5.15 I was able to bisect this to 5.15.18, where this commit was responsible (b89ddf4cca43 upstream): * 9c82ce593626 arm64/bpf: Remove 128MB limit for BPF JIT programs Reverting this commit in 5.15.18 resolves the issue. The issue is also present in 5.19-rc6. In addition to that, I noticed that on my personal kernel build this doesn't happen on any kernel version. After many attempts at config reconciliation, I narrowed it down to CONFIG_PROC_KCORE. When the option is enabled and the commit b89ddf4cca43 is present, the stacks have no kernel symbols. This seems like a regression.