From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-182.mta1.migadu.com (out-182.mta1.migadu.com [95.215.58.182]) (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 3921410F2 for ; Thu, 5 Feb 2026 03:45:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770263143; cv=none; b=Px8PP4s7sD+/6wiHvhaNUkmwwOJ90ndVxl/b2e+8IKb2eOrsNwsjDxVhtT/8czH6maLX74ScU/My6Y9HOrfClad5+8FnI4KOVv6AFjyIq1DeKSucfOLK35iKayItWX7yxWu8t/fMbvOyfTULduHLVb0LM+s5o5KqEnteUyhuWRM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770263143; c=relaxed/simple; bh=WJ/jeHkIfNNujYEUHSpYWtmxLO6yVMycMG1TYHXvJ/s=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ESWHXZLzNbP89xLsYF02fLU1iRspfi053ydS75Zjbxcjh0mOIfqqk5eAKficVtJfz/pllySzyQ0LY55x3Ic4wAoPBwupjYd6bwqFEuRUdjFKX4ZyP0cAz4kWEButJApSwa1/d2W9olN89Z/rzZPQVsayqeUoX10JdCkWaC9YCsw= 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=P2N0/gsD; arc=none smtp.client-ip=95.215.58.182 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="P2N0/gsD" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1770263131; 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=ikkVCtqFFnuGi3PCNZVDX6A6swIGnFYJIrnmzPcH2b4=; b=P2N0/gsD+bqwC6ZgFow5sgOtkoDtUELLLhFP/R4AemtFYv4ne/e0HWcKQZSAgRI0g0n6u+ OluPkCP/SWLydIxuWA9jKWAesBekbg+JyIV2iN3pYJm1GHcjuV6iRY24lR8cS1uT40ZIy7 rooxv3GMniRBsv4ZERBF5+vAaXsQslw= Date: Thu, 5 Feb 2026 11:45:14 +0800 Precedence: bulk X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next v9 8/9] libbpf: Add syscall common attributes support for map_create Content-Language: en-US To: Andrii Nakryiko Cc: bpf@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Shuah Khan , Christian Brauner , Seth Forshee , Yuichiro Tsuji , Andrey Albershteyn , Willem de Bruijn , Jason Xing , Tao Chen , Mykyta Yatsenko , Kumar Kartikeya Dwivedi , Anton Protopopov , Amery Hung , Rong Tao , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-kselftest@vger.kernel.org, kernel-patches-bot@fb.com References: <20260202144046.30651-1-leon.hwang@linux.dev> <20260202144046.30651-9-leon.hwang@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Leon Hwang In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 5/2/26 03:48, Andrii Nakryiko wrote: > On Mon, Feb 2, 2026 at 6:43 AM Leon Hwang wrote: >> >> With the previous commit adding common attribute support for >> BPF_MAP_CREATE, users can now retrieve detailed error messages when map >> creation fails via the log_buf field. >> >> Introduce struct bpf_log_opts with the following fields: >> log_buf, log_size, log_level, and log_true_size. >> >> Extend bpf_map_create_opts with a new field log_opts, allowing users to >> capture and inspect log messages on map creation failures. >> >> Signed-off-by: Leon Hwang >> --- >> tools/lib/bpf/bpf.c | 16 +++++++++++++++- >> tools/lib/bpf/bpf.h | 17 ++++++++++++++++- >> 2 files changed, 31 insertions(+), 2 deletions(-) >> > > LGTM > > Acked-by: Andrii Nakryiko > Thanks for your review. >> diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c >> index 9d8740761b7a..0c3e40844d80 100644 >> --- a/tools/lib/bpf/bpf.c >> +++ b/tools/lib/bpf/bpf.c >> @@ -209,6 +209,9 @@ int bpf_map_create(enum bpf_map_type map_type, >> const struct bpf_map_create_opts *opts) >> { >> const size_t attr_sz = offsetofend(union bpf_attr, excl_prog_hash_size); >> + const size_t attr_common_sz = sizeof(struct bpf_common_attr); >> + struct bpf_common_attr attr_common; >> + struct bpf_log_opts *log_opts; >> union bpf_attr attr; >> int fd; >> >> @@ -242,7 +245,18 @@ int bpf_map_create(enum bpf_map_type map_type, >> attr.excl_prog_hash = ptr_to_u64(OPTS_GET(opts, excl_prog_hash, NULL)); >> attr.excl_prog_hash_size = OPTS_GET(opts, excl_prog_hash_size, 0); >> >> - fd = sys_bpf_fd(BPF_MAP_CREATE, &attr, attr_sz); >> + log_opts = OPTS_GET(opts, log_opts, NULL); >> + if (log_opts && feat_supported(NULL, FEAT_BPF_SYSCALL_COMMON_ATTRS)) { >> + memset(&attr_common, 0, attr_common_sz); >> + attr_common.log_buf = ptr_to_u64(OPTS_GET(log_opts, log_buf, NULL)); >> + attr_common.log_size = OPTS_GET(log_opts, log_size, 0); >> + attr_common.log_level = OPTS_GET(log_opts, log_level, 0); >> + fd = sys_bpf_ext_fd(BPF_MAP_CREATE, &attr, attr_sz, &attr_common, attr_common_sz); >> + OPTS_SET(log_opts, log_true_size, attr_common.log_true_size); >> + } else { >> + fd = sys_bpf_fd(BPF_MAP_CREATE, &attr, attr_sz); >> + OPTS_SET(log_opts, log_true_size, 0); >> + } >> return libbpf_err_errno(fd); >> } >> >> diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h >> index 2c8e88ddb674..59673f094f86 100644 >> --- a/tools/lib/bpf/bpf.h >> +++ b/tools/lib/bpf/bpf.h >> @@ -37,6 +37,18 @@ extern "C" { >> >> LIBBPF_API int libbpf_set_memlock_rlim(size_t memlock_bytes); >> >> +struct bpf_log_opts { >> + size_t sz; /* size of this struct for forward/backward compatibility */ >> + >> + char *log_buf; >> + __u32 log_size; >> + __u32 log_level; >> + __u32 log_true_size; > > please mention in the comment here that this is an out parameter set > by the kernel > Ack. I'll add a comment in the next revision. Thanks, Leon >> + >> + size_t :0; >> +}; >> +#define bpf_log_opts__last_field log_true_size >> + >> struct bpf_map_create_opts { >> size_t sz; /* size of this struct for forward/backward compatibility */ >> >> @@ -57,9 +69,12 @@ struct bpf_map_create_opts { >> >> const void *excl_prog_hash; >> __u32 excl_prog_hash_size; >> + >> + struct bpf_log_opts *log_opts; >> + >> size_t :0; >> }; >> -#define bpf_map_create_opts__last_field excl_prog_hash_size >> +#define bpf_map_create_opts__last_field log_opts >> >> LIBBPF_API int bpf_map_create(enum bpf_map_type map_type, >> const char *map_name, >> -- >> 2.52.0 >>