From patchwork Mon Apr 3 11:20:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florent Revest X-Patchwork-Id: 13198069 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 8D3D6C761A6 for ; Mon, 3 Apr 2023 11:21:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231655AbjDCLVb (ORCPT ); Mon, 3 Apr 2023 07:21:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50402 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232348AbjDCLVa (ORCPT ); Mon, 3 Apr 2023 07:21:30 -0400 Received: from mail-wr1-x433.google.com (mail-wr1-x433.google.com [IPv6:2a00:1450:4864:20::433]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 532231117E for ; Mon, 3 Apr 2023 04:21:23 -0700 (PDT) Received: by mail-wr1-x433.google.com with SMTP id y14so28974535wrq.4 for ; Mon, 03 Apr 2023 04:21:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1680520882; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=yfXbK+ehjb3x3tftRCKApX1xRkjQHv0ANTDTDP3NxOc=; b=LP5ajRRnzT235CHmQ0lWGzS01yRL1tgN2As0C6a9k+8kESyhDzgjyXI8/BDjLJaUTJ WsvByzsfaG8Sorgy//fxlbYOVC0mNesRhPJwZdh9m0lkowm6Q44RL+WC5zrfnawtMqAp spVLCXyWFMFo1ZXSL+bQvrMPVbziP+EyTRhcA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680520882; 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=yfXbK+ehjb3x3tftRCKApX1xRkjQHv0ANTDTDP3NxOc=; b=stVqYXa2MUZDXtwjAq8tZL89oFCjwvk4wkIfeQhx2RDCqagB9eaehJbZgy1KbnKzYR i7+AlS/ufaCxzNn1WAg1UcHMRJ5KISutwvA8lcQ3a/7xJkX+gULQO4joBEc4MTgYiRqz 2rL13t/8+XruWIvpGoDMo+rJm/z++Hqds1SRoCYwmm6uWyc6qODxxYfiN//rthaKUZzs wAVfkKRmOUjGgoxiFXhZ+8BbLN5P3c0fazAyX2tTanT6ISRUaVPz00hHBsYcJl06GUAU fQeUdVHtAfq73C4ZA9M48leN390H3l+68xE/y4wcYp/75RgTIkr/Px4MQEUXRCDmVm0o 0sJg== X-Gm-Message-State: AAQBX9cLiVpJEEdJOgB47oJBDD/UB2qGMECQKITLXV2w2Zkp+cd3ItEW sSDMQAXLfbEJs0KzKovawFyvNw== X-Google-Smtp-Source: AKy350YH8mOD0Si3cDk+4jVUPMTXC/FAXN6Jt/A0MkgFu+t8zSiQuC5DogJ94PDR//YD6KjdIBX/GQ== X-Received: by 2002:adf:e90c:0:b0:2cf:eeae:88c3 with SMTP id f12-20020adfe90c000000b002cfeeae88c3mr28245477wrm.32.1680520881678; Mon, 03 Apr 2023 04:21:21 -0700 (PDT) Received: from revest.zrh.corp.google.com ([2a00:79e0:9d:6:b5a2:4ffd:8524:ac1]) by smtp.gmail.com with ESMTPSA id u13-20020adfeb4d000000b002daeb108304sm9510031wrn.33.2023.04.03.04.21.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Apr 2023 04:21:21 -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 v4 0/4] Add ftrace direct call for arm64 Date: Mon, 3 Apr 2023 13:20:55 +0200 Message-Id: <20230403112059.2749695-1-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: linux-trace-kernel@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 v3 [3]: - Added "BTI C" instructions at the beginning of each ftrace direct call sample - Added Mark Rutland's Acked-by to patch 2 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/20230324171451.2752302-1-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 | 32 +++++++ samples/ftrace/ftrace-direct-multi-modify.c | 36 ++++++++ samples/ftrace/ftrace-direct-multi.c | 22 +++++ samples/ftrace/ftrace-direct-too.c | 25 ++++++ samples/ftrace/ftrace-direct.c | 23 +++++ tools/testing/selftests/bpf/DENYLIST.aarch64 | 82 ++---------------- 11 files changed, 288 insertions(+), 102 deletions(-)