From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-186.mta0.migadu.com (out-186.mta0.migadu.com [91.218.175.186]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E35271DC98B for ; Fri, 6 Jun 2025 05:52:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.186 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749189150; cv=none; b=Q33Y/BjE4plYnLKRUIYbAarM7tSd0pNRKJ6+DZAPArvcsxhUiWawkfzPX/RiVyYmVcclRr2xQgoKbpoNmkfHfOEwBoJbiJn1j/D3yGGHW2qIjUjENrHQfBAuLElFVP6trvUk4abEQ2gcQhAFw2L3eWPpUiBFD64XBXVdWxJofgQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749189150; c=relaxed/simple; bh=/OJ0cvQnW3DliJASGXCLBT9ojXKWMODlqOomjJdoKkQ=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=OqOKWHarMSsPEnHqn6Em0pRAhFzxTOCakzCXK8YLfT7RWcUvUFLADgcDRkxxAeWsbCGhLhBtETB8D9aTtwlOT7YIlYLzJPxZuQFn870XtXu4D+/TQTAOx7o0c9FJgmL/hGG9B6t590KhmfNulj3HHe19u0inJ2aJTMpa0YQqYDk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=v7K5wrqq; arc=none smtp.client-ip=91.218.175.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="v7K5wrqq" Message-ID: <22e00248-0b0a-457e-8516-d19d38ac15f9@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1749189142; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bclVK56KwBCGNf2eDoJOZMmHkl+n2Q92FeftMxTy+eg=; b=v7K5wrqqK4q3VzyaPy+zIJ5AHLcq9Ydj4rv3DKjsMEQT9hFHyT+5yibroVNxOqrey4zCYu lYi6DjC+Tx6EIciWuM65CDh3Py5KjogQc3EjqNcvqYIGZfRhso910Utl0zy79p9KMq0T/9 L8QgirsZ5ULxddWwzRqJm0LPoL864JY= Date: Thu, 5 Jun 2025 22:52:17 -0700 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next 4/4] selftests/bpf: Fix a user_ringbuf failure with arm64 64KB page size Content-Language: en-GB X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yonghong Song To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , kernel-team@fb.com, Martin KaFai Lau References: <20250606032309.444401-1-yonghong.song@linux.dev> <20250606032330.446016-1-yonghong.song@linux.dev> In-Reply-To: <20250606032330.446016-1-yonghong.song@linux.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 6/5/25 8:23 PM, Yonghong Song wrote: > The ringbuf max_entries must be PAGE_ALIGNED. See kernel function > ringbuf_map_alloc(). So for arm64 64KB page size, adjust max_entries > properly. > > Signed-off-by: Yonghong Song > --- > tools/testing/selftests/bpf/prog_tests/user_ringbuf.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c b/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c > index d424e7ecbd12..f50aa8e7f6c2 100644 > --- a/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c > +++ b/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c > @@ -21,8 +21,7 @@ > #include "../progs/test_user_ringbuf.h" > > static const long c_sample_size = sizeof(struct sample) + BPF_RINGBUF_HDR_SZ; > -static const long c_ringbuf_size = 1 << 12; /* 1 small page */ > -static const long c_max_entries = c_ringbuf_size / c_sample_size; > +static long c_ringbuf_size, c_max_entries; > > static void drain_current_samples(void) > { > @@ -686,6 +685,9 @@ void test_user_ringbuf(void) > { > int i; > > + c_ringbuf_size = getpagesize(); /* 1 page */ > + c_max_entries = c_ringbuf_size / c_sample_size; > + > for (i = 0; i < ARRAY_SIZE(success_tests); i++) { > if (!test__start_subtest(success_tests[i].test_name)) > continue; CI reports a build failure error: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c:426:2: error: call to '__compiletime_assert_0' declared with 'error' attribute: BUILD_BUG_ON failed: total_samples <= c_max_entries 426 | BUILD_BUG_ON(total_samples <= c_max_entries | /tmp/work/bpf/bpf/tools/include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON' 50 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) | ^ /tmp/work/bpf/bpf/tools/include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG' 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) | ^ /tmp/work/bpf/bpf/tools/include/linux/compiler.h:37:2: note: expanded from macro 'compiletime_assert' 37 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^ /tmp/work/bpf/bpf/tools/include/linux/compiler.h:25:2: note: expanded from macro '_compiletime_assert' 25 | __compiletime_assert(condition, msg, prefix, suffix) | ^ /tmp/work/bpf/bpf/tools/include/linux/compiler.h:18:4: note: expanded from macro '__compiletime_assert' 18 | prefix ## suffix(); \ | ^ :60:1: note: expanded from here 60 | __compiletime_assert_0 | ^ This happens for the release build (RELEASE=1 in build command line where -O2 is used in stead of -O0). Converting the BUILD_BUG_ON to ASSERT can fix the problem. diff --git a/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c b/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c index f50aa8e7f6c2..467b5b8beecc 100644 --- a/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c +++ b/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c @@ -423,7 +423,9 @@ static void test_user_ringbuf_loop(void) uint32_t remaining_samples = total_samples; int err; - BUILD_BUG_ON(total_samples <= c_max_entries); + if (!ASSERT_LE(total_samples, c_max_entries, "compare_c_max_entries")) + return; + err = load_skel_create_user_ringbuf(&skel, &ringbuf); I will wait for some further comments before posting v2.