From patchwork Mon Apr 3 11:35:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florent Revest X-Patchwork-Id: 13198088 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 1FEA5C76196 for ; Mon, 3 Apr 2023 11:36:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232020AbjDCLgE (ORCPT ); Mon, 3 Apr 2023 07:36:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232482AbjDCLgD (ORCPT ); Mon, 3 Apr 2023 07:36:03 -0400 Received: from mail-wm1-x330.google.com (mail-wm1-x330.google.com [IPv6:2a00:1450:4864:20::330]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D162911E9B for ; Mon, 3 Apr 2023 04:35:59 -0700 (PDT) Received: by mail-wm1-x330.google.com with SMTP id l10-20020a05600c1d0a00b003f04bd3691eso3014774wms.5 for ; Mon, 03 Apr 2023 04:35:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1680521758; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=i0HG+W1Nr/Zm5XRUMWQUndq8bum7JqRDYebIXh9Qbe0=; b=ADin8NDRYe5sQ0hrQPtqSRLSxBB8ihn7EpyAUhlsyrOcCkUj61zdV9iPRft+pFLa0x E09qWvv0++B5plr6iXhNTTdYGo23EMPXVy1xwh6WqY7AGjsf4MFmGNH4LhqH19kBPAP7 dVdDRTCTSY0MHjb/HLXDSl+4C4hbkxyfphfSE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680521758; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=i0HG+W1Nr/Zm5XRUMWQUndq8bum7JqRDYebIXh9Qbe0=; b=aQtLH1LXxhwwgthq1tHy57XUiyHoKsu4xZBl2oxc81ZdaLwASMgUgcLsyjVCfrr1+m aFiqoEs5cnSGNlGJ1E4KKfWom+YbS6iVX5GnH4v4wBiMNT4wbXIuA6sIVGP6EaMu6KPP W1wKNuYmH/kn46dXxXsxjWe7ITRpA+VQw8lBRIk/mRur0VIFiEoUAGqKPR1dvQbzaKK1 OeuAqPwK/0nqxSoJxr6UzFEYITIyBkuGIp3JoUwTbi2w9luDnKXy+7UlN7axHi86z4vI aOmrPxwLLZyggtN/9Tng93aDj8YLaL4jl6Y6RxRQMtljESfwSNI20rtt2ZlYJ8V1OuT7 lTVQ== X-Gm-Message-State: AO0yUKVVrurmEhVf8nRWYCNYrayGv6sAu1xXgo7FaSYEWVAZaKihbkkz ylz3SWYsl4ulWCUMsYxPdy7xjQ== X-Google-Smtp-Source: AK7set/4kJW+CgDqrDOz4wXVt98om3F+A+nmj93tUu871u1MurFxeTkkxPOfkG6PPH56agG15HqArw== X-Received: by 2002:a05:600c:2312:b0:3ee:b3bf:5f7c with SMTP id 18-20020a05600c231200b003eeb3bf5f7cmr27217057wmo.23.1680521758197; Mon, 03 Apr 2023 04:35:58 -0700 (PDT) Received: from revest.zrh.corp.google.com ([2a00:79e0:9d:6:b5a2:4ffd:8524:ac1]) by smtp.gmail.com with ESMTPSA id s15-20020a05600c45cf00b003eb2e33f327sm29841410wmo.2.2023.04.03.04.35.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Apr 2023 04:35:57 -0700 (PDT) From: Florent Revest To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org Cc: catalin.marinas@arm.com, will@kernel.org, rostedt@goodmis.org, mhiramat@kernel.org, mark.rutland@arm.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kpsingh@kernel.org, jolsa@kernel.org, xukuohai@huaweicloud.com, lihuafei1@huawei.com, Florent Revest Subject: [PATCH v5 0/4] Add ftrace direct call for arm64 Date: Mon, 3 Apr 2023 13:35:48 +0200 Message-Id: <20230403113552.2857693-1-revest@chromium.org> X-Mailer: git-send-email 2.40.0.423.gd6c402a77b-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This series adds ftrace direct call support to arm64. This makes BPF tracing programs (fentry/fexit/fmod_ret/lsm) work on arm64. It is meant to be taken by the arm64 tree but it depends on the trace-direct-v6.3-rc3 tag of the linux-trace tree: git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git That tag was created by Steven Rostedt so the arm64 tree can pull the prior work this depends on. [1] Thanks to the ftrace refactoring under that tag, an ftrace_ops backing a ftrace direct call will only ever point to *one* direct call. This means we can look up the direct called trampoline address stored in the ops from the ftrace_caller trampoline in the case when the destination would be out of reach of a BL instruction at the ftrace callsite. This fixes limitations of previous attempts such as [2]. This series has been tested on arm64 with: 1- CONFIG_FTRACE_SELFTEST 2- samples/ftrace/*.ko (cf: patch 3) 3- tools/testing/selftests/bpf/test_progs (cf: patch 4) Changes since v4 [3]: - *Actually* added "BTI C" instructions at the beginning of each ftrace direct call sample (v4 was supposed to do that but I forgot to git commit --amend...) 1: https://lore.kernel.org/all/ZB2Nl7fzpHoq5V20@FVFF77S0Q05N/ 2: https://lore.kernel.org/all/20220913162732.163631-1-xukuohai@huaweicloud.com/ 3: https://lore.kernel.org/bpf/20230403112059.2749695-1-revest@chromium.org/ Florent Revest (4): arm64: ftrace: Add direct call support arm64: ftrace: Simplify get_ftrace_plt arm64: ftrace: Add direct call trampoline samples support selftests/bpf: Update the tests deny list on aarch64 arch/arm64/Kconfig | 6 ++ arch/arm64/include/asm/ftrace.h | 22 +++++ arch/arm64/kernel/asm-offsets.c | 6 ++ arch/arm64/kernel/entry-ftrace.S | 90 ++++++++++++++++---- arch/arm64/kernel/ftrace.c | 46 +++++++--- samples/ftrace/ftrace-direct-modify.c | 34 ++++++++ samples/ftrace/ftrace-direct-multi-modify.c | 38 +++++++++ samples/ftrace/ftrace-direct-multi.c | 23 +++++ samples/ftrace/ftrace-direct-too.c | 26 ++++++ samples/ftrace/ftrace-direct.c | 24 ++++++ tools/testing/selftests/bpf/DENYLIST.aarch64 | 82 ++---------------- 11 files changed, 295 insertions(+), 102 deletions(-)