From patchwork Mon Oct 25 08:33:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 12580995 X-Patchwork-Delegate: bpf@iogearbox.net 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F1B9C433EF for ; Mon, 25 Oct 2021 08:34:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 793B560EE9 for ; Mon, 25 Oct 2021 08:34:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232664AbhJYIhP (ORCPT ); Mon, 25 Oct 2021 04:37:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232541AbhJYIgc (ORCPT ); Mon, 25 Oct 2021 04:36:32 -0400 Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 19D38C06118D; Mon, 25 Oct 2021 01:34:06 -0700 (PDT) Received: by mail-pj1-x102b.google.com with SMTP id gn3so7715906pjb.0; Mon, 25 Oct 2021 01:34:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=FimO42wHtyfBgzya/uAaxmcTkfbAGy9rm+wuLjXRCpM=; b=CMzBBLZvEjXS7erkK4gC8zgIdfsYiNz7dGUg+d49ScAYY+q/TShlcX2Ju9kusSxdEb a01pYcPiTgrVOP16z1WWCDbus2MLMoqyEtRZsKF/7I+556oB8thmUiWvwLCCpaKcQafk Q90z1GqDhsyVHwTvOPZwkwT2UGNiLDen6CuNr1/umo5xRLQ0dY8i6HLK+wtn+TAosQfr Gx9CNRh8KkLCvQ8YsPpvVqpNHjwYP40LzSyOVqHsNeZe1Gq2hOhsXNidrxl2ApprLLfy +sgZXnWrt+SqR2w8WyrxCCvutwz8aEMBZtUCHn0oVbuzBtSXFuPLQphqjh15nH9ExfPA M8FQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=FimO42wHtyfBgzya/uAaxmcTkfbAGy9rm+wuLjXRCpM=; b=LHzJCXNPTUUn9d2DPLnw+oNJ6bBmtMCpkxp1Bo83EDtimHesMe7zOVpgeC3XIFUgaH icqDuVN0odDyF5BJxnc/7cCxODyh9HlTAGZQhunnu23akoLUYPpNEDA1T6850BC3ooH1 1TcFKP8Cc0c1wtJLLBQr4LFL7m10NOCUcchJHzjUMdOnebZLuU8jegqcPVLwZ2IG5+La qUk1qZbm6WQabvUYfLy2dfgWJr1AoAhSAwy6eBNCeLqUfHrdNUw226r7Vid1FDz95z9U /Sy4M8GSxF5ZMnvT6nfh7dWcJAggLsTgNWQfRXnk/vdQGuBrxgAOy1/I5wbgj91JDxrd Y7aA== X-Gm-Message-State: AOAM532/+4JV/EFegz+6JRrLrQoBGoOfqalcBogiKqLrL5q28UI5eh/Y dl/tjM/nV6aNWsxOLXo3IYQ= X-Google-Smtp-Source: ABdhPJz2AlsUyCzUZMxKu+M0vjHOcLRcbjq0i+wwmiMJBlPaI9iPLMs9CncCZefQOcgo7EXDtDLr1Q== X-Received: by 2002:a17:90a:62c9:: with SMTP id k9mr21015248pjs.52.1635150845679; Mon, 25 Oct 2021 01:34:05 -0700 (PDT) Received: from localhost.localdomain ([140.82.17.67]) by smtp.gmail.com with ESMTPSA id p13sm2495694pfo.102.2021.10.25.01.34.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Oct 2021 01:34:05 -0700 (PDT) From: Yafang Shao To: akpm@linux-foundation.org, keescook@chromium.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, arnaldo.melo@gmail.com, pmladek@suse.com, peterz@infradead.org, viro@zeniv.linux.org.uk, valentin.schneider@arm.com, qiang.zhang@windriver.com, robdclark@chromium.org, christian@brauner.io, dietmar.eggemann@arm.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, davem@davemloft.net, kuba@kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, dennis.dalessandro@cornelisnetworks.com, mike.marciniszyn@cornelisnetworks.com, dledford@redhat.com, jgg@ziepe.ca Cc: linux-rdma@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, oliver.sang@intel.com, lkp@intel.com, Yafang Shao , Andrii Nakryiko Subject: [PATCH v6 10/12] tools/testing/selftests/bpf: make it adopt to task comm size change Date: Mon, 25 Oct 2021 08:33:13 +0000 Message-Id: <20211025083315.4752-11-laoar.shao@gmail.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20211025083315.4752-1-laoar.shao@gmail.com> References: <20211025083315.4752-1-laoar.shao@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net The hard-coded 16 is used in various bpf progs. These progs get task comm either via bpf_get_current_comm() or prctl() or bpf_core_read_str(), all of which can work well even if the task comm size is changed. In these BPF programs, one thing to be improved is the sched:sched_switch tracepoint args. As the tracepoint args are derived from the kernel, we'd better make it same with the kernel. So the macro TASK_COMM_LEN is converted to type enum, then all the BPF programs can get it through BTF. Signed-off-by: Yafang Shao Cc: Mathieu Desnoyers Cc: Arnaldo Carvalho de Melo Cc: Andrii Nakryiko Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Al Viro Cc: Kees Cook Cc: Petr Mladek --- include/linux/sched.h | 9 +++++++-- tools/testing/selftests/bpf/progs/test_stacktrace_map.c | 6 +++--- tools/testing/selftests/bpf/progs/test_tracepoint.c | 6 +++--- 3 files changed, 13 insertions(+), 8 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index c1a927ddec64..124538db792c 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -274,8 +274,13 @@ struct task_group; #define get_current_state() READ_ONCE(current->__state) -/* Task command name length: */ -#define TASK_COMM_LEN 16 +/* + * Define the task command name length as enum, then it can be visible to + * BPF programs. + */ +enum { + TASK_COMM_LEN = 16, +}; extern void scheduler_tick(void); diff --git a/tools/testing/selftests/bpf/progs/test_stacktrace_map.c b/tools/testing/selftests/bpf/progs/test_stacktrace_map.c index 00ed48672620..e9b602a6dc1b 100644 --- a/tools/testing/selftests/bpf/progs/test_stacktrace_map.c +++ b/tools/testing/selftests/bpf/progs/test_stacktrace_map.c @@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2018 Facebook -#include +#include #include #ifndef PERF_MAX_STACK_DEPTH @@ -41,11 +41,11 @@ struct { /* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */ struct sched_switch_args { unsigned long long pad; - char prev_comm[16]; + char prev_comm[TASK_COMM_LEN]; int prev_pid; int prev_prio; long long prev_state; - char next_comm[16]; + char next_comm[TASK_COMM_LEN]; int next_pid; int next_prio; }; diff --git a/tools/testing/selftests/bpf/progs/test_tracepoint.c b/tools/testing/selftests/bpf/progs/test_tracepoint.c index 4b825ee122cf..f21982681e28 100644 --- a/tools/testing/selftests/bpf/progs/test_tracepoint.c +++ b/tools/testing/selftests/bpf/progs/test_tracepoint.c @@ -1,17 +1,17 @@ // SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2017 Facebook -#include +#include #include /* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */ struct sched_switch_args { unsigned long long pad; - char prev_comm[16]; + char prev_comm[TASK_COMM_LEN]; int prev_pid; int prev_prio; long long prev_state; - char next_comm[16]; + char next_comm[TASK_COMM_LEN]; int next_pid; int next_prio; };