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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E7A1C433F5 for ; Mon, 29 Nov 2021 13:42:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A70946B0071; Mon, 29 Nov 2021 08:41:59 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A202F6B0072; Mon, 29 Nov 2021 08:41:59 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8E78C6B0073; Mon, 29 Nov 2021 08:41:59 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0022.hostedemail.com [216.40.44.22]) by kanga.kvack.org (Postfix) with ESMTP id 81ACE6B0071 for ; Mon, 29 Nov 2021 08:41:59 -0500 (EST) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 448B1180CB061 for ; Mon, 29 Nov 2021 13:41:49 +0000 (UTC) X-FDA: 78862080738.13.E7F52CD Received: from mail-qt1-f175.google.com (mail-qt1-f175.google.com [209.85.160.175]) by imf30.hostedemail.com (Postfix) with ESMTP id 8B217E00198C for ; Mon, 29 Nov 2021 13:41:38 +0000 (UTC) Received: by mail-qt1-f175.google.com with SMTP id o17so16563323qtk.1 for ; Mon, 29 Nov 2021 05:41:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=fhEsQAK98bM5StiE4nhRYixbgK7BmdEmPc2JUmkzNuE=; b=OPD4a0BbOCx/FwKr9ugrv/ROrF8AV8trJRIupc+DGvBkpArkblK6Vf7ThfjN45aaQx +4tY0VYjZJxl8P1vbJ++e/HVMPYxXgxG7oPThz/y4Eyks1pROtqYrnlq27waj1Jvwhxn O1n97pTLMFzxnBa4efTROYFYfSml95/Ip3O7RBzVZvGZYo6+ChdPL8s0o2JFx2gDz7oQ RSQp/sslhuaFaXPYGRHaRVNKgR3xBYeXrI+SvAsiJXQkWnzqqQL3yFqzQ3ebLgRwmLo6 ZJKNwzLsde6LoPB7PutSs3sH0wX6epaXkVO3m1jHVMV1yfypRsT1W5T5hQAJIvfPTIvN dN9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=fhEsQAK98bM5StiE4nhRYixbgK7BmdEmPc2JUmkzNuE=; b=vkeg8cgsJd+vSGs1pEkiQzf/HAFtUT2YXz6XPMkfqiz4dwLHBCRhvvPabsgGGYk28+ GZyiIMONJpPLJ6zj7yyj/60dnbI+nj6ry5bu536LiT56z19cJoXRIcvRvKejPYGcq4wS /hLOuo0lrobqpdVqvSJK48KqGN2Lg5AxOpkLOgmVhagb7SfaM51q5tTnhsmrTAszlrX3 2j1z7+OHGa9/mVL2fkDe5ZYwEIW5obYvNG0TLTfDGOTnux5/TU3w1Zona0Ki9S+ajqP5 mt5Aoy91U8vkzjyUMC+F2XhzaNgbmsK/payMvATCeXIi108oe79hWdE1yDSTb3FkXAHX c34A== X-Gm-Message-State: AOAM5333U9BeF9VkvpKaiGcKQCPOaWuEsRkTgPd+TKXe8LsoQ87gdu7M kXtbnmivlfPE1a4VDHHwKBxxQvrfwW8iDTzCcV8= X-Google-Smtp-Source: ABdhPJwtYuAs3Eyp35qBUS3u4YeJbSdbd0Fj/uaKBQS5Zkwii/UENBRf3c8ern+XfOlGXgg+DCkb17rNDqYBaO6+dq4= X-Received: by 2002:ac8:5894:: with SMTP id t20mr34675354qta.450.1638193308018; Mon, 29 Nov 2021 05:41:48 -0800 (PST) MIME-Version: 1.0 References: <20211120112738.45980-1-laoar.shao@gmail.com> <20211120112738.45980-8-laoar.shao@gmail.com> In-Reply-To: From: Yafang Shao Date: Mon, 29 Nov 2021 21:41:11 +0800 Message-ID: Subject: Re: [PATCH v2 7/7] tools/testing/selftests/bpf: replace open-coded 16 with TASK_COMM_LEN To: Sven Schnelle Cc: Andrew Morton , netdev , bpf , "linux-perf-use." , linux-fsdevel@vger.kernel.org, Linux MM , LKML , kernel test robot , kbuild test robot , Andrii Nakryiko , David Hildenbrand , Mathieu Desnoyers , Arnaldo Carvalho de Melo , Andrii Nakryiko , Michal Miroslaw , Peter Zijlstra , Steven Rostedt , Matthew Wilcox , Al Viro , Kees Cook , Petr Mladek Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 8B217E00198C X-Stat-Signature: y97mfsroa3999cdchz8jyfxg46u3q1gz Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=OPD4a0Bb; spf=pass (imf30.hostedemail.com: domain of laoar.shao@gmail.com designates 209.85.160.175 as permitted sender) smtp.mailfrom=laoar.shao@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-HE-Tag: 1638193298-258090 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Nov 29, 2021 at 6:13 PM Sven Schnelle wrote: > > Hi, > > Yafang Shao writes: > > > As the sched:sched_switch 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. > > > > The BPF program which wants to use TASK_COMM_LEN should include the header > > vmlinux.h. Regarding the test_stacktrace_map and test_tracepoint, as the > > type defined in linux/bpf.h are also defined in vmlinux.h, so we don't > > need to include linux/bpf.h again. > > > > Signed-off-by: Yafang Shao > > Acked-by: Andrii Nakryiko > > Acked-by: David Hildenbrand > > Cc: Mathieu Desnoyers > > Cc: Arnaldo Carvalho de Melo > > Cc: Andrii Nakryiko > > Cc: Michal Miroslaw > > Cc: Peter Zijlstra > > Cc: Steven Rostedt > > Cc: Matthew Wilcox > > Cc: David Hildenbrand > > 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 78c351e35fec..cecd4806edc6 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, > > +}; > > This breaks the trigger-field-variable-support.tc from the ftrace test > suite at least on s390: > > echo 'hist:keys=next_comm:wakeup_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,sched.sched_waking.prio,next_comm) if next_comm=="ping"' > linux/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-field-variable-support.tc: line 15: echo: write error: Invalid argument > > I added a debugging line into check_synth_field(): > > [ 44.091037] field->size 16, hist_field->size 16, field->is_signed 1, hist_field->is_signed 0 > > Note the difference in the signed field. > Hi Sven, Thanks for the report and debugging! Seems we should explicitly define it as signed ? Could you pls. help verify it? diff --git a/include/linux/sched.h b/include/linux/sched.h index cecd4806edc6..44d36c6af3e1 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -278,7 +278,7 @@ struct task_group; * Define the task command name length as enum, then it can be visible to * BPF programs. */ -enum { +enum SignedEnum { TASK_COMM_LEN = 16, }; -- Thanks Yafang