From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) (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 794E11DA44 for ; Wed, 3 Jan 2024 22:23:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=meta.com Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 403MFFq5001650 for ; Wed, 3 Jan 2024 14:23:43 -0800 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3vdg7401jh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 03 Jan 2024 14:23:42 -0800 Received: from twshared10507.42.prn1.facebook.com (2620:10d:c0a8:1b::30) by mail.thefacebook.com (2620:10d:c0a8:83::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.34; Wed, 3 Jan 2024 14:23:37 -0800 Received: by devbig019.vll3.facebook.com (Postfix, from userid 137359) id B9C493DF9EBA8; Wed, 3 Jan 2024 14:21:25 -0800 (PST) From: Andrii Nakryiko To: , , , , CC: , , Subject: [PATCH bpf-next 22/29] libbpf: further decouple feature checking logic from bpf_object Date: Wed, 3 Jan 2024 14:20:27 -0800 Message-ID: <20240103222034.2582628-23-andrii@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240103222034.2582628-1-andrii@kernel.org> References: <20240103222034.2582628-1-andrii@kernel.org> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-ORIG-GUID: z9i4_73ckrFmkfAgEZ05VZhrHHvujxA2 X-Proofpoint-GUID: z9i4_73ckrFmkfAgEZ05VZhrHHvujxA2 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2024-01-03_08,2024-01-03_01,2023-05-22_02 Add feat_supported() helper that accepts feature cache instead of bpf_object. This allows low-level code in bpf.c to not know or care about higher-level concept of bpf_object, yet it will be able to utilize custom feature checking in cases where BPF token might influence the outcome. Acked-by: John Fastabend Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/bpf.c | 6 +++--- tools/lib/bpf/libbpf.c | 22 +++++++++++++++------- tools/lib/bpf/libbpf_internal.h | 5 ++++- 3 files changed, 22 insertions(+), 11 deletions(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index d69137459abf..10bf11a758bf 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -146,7 +146,7 @@ int bump_rlimit_memlock(void) struct rlimit rlim; =20 /* if kernel supports memcg-based accounting, skip bumping RLIMIT_MEMLO= CK */ - if (memlock_bumped || kernel_supports(NULL, FEAT_MEMCG_ACCOUNT)) + if (memlock_bumped || feat_supported(NULL, FEAT_MEMCG_ACCOUNT)) return 0; =20 memlock_bumped =3D true; @@ -181,7 +181,7 @@ int bpf_map_create(enum bpf_map_type map_type, return libbpf_err(-EINVAL); =20 attr.map_type =3D map_type; - if (map_name && kernel_supports(NULL, FEAT_PROG_NAME)) + if (map_name && feat_supported(NULL, FEAT_PROG_NAME)) libbpf_strlcpy(attr.map_name, map_name, sizeof(attr.map_name)); attr.key_size =3D key_size; attr.value_size =3D value_size; @@ -265,7 +265,7 @@ int bpf_prog_load(enum bpf_prog_type prog_type, attr.kern_version =3D OPTS_GET(opts, kern_version, 0); attr.prog_token_fd =3D OPTS_GET(opts, token_fd, 0); =20 - if (prog_name && kernel_supports(NULL, FEAT_PROG_NAME)) + if (prog_name && feat_supported(NULL, FEAT_PROG_NAME)) libbpf_strlcpy(attr.prog_name, prog_name, sizeof(attr.prog_name)); attr.license =3D ptr_to_u64(license); =20 diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 95a7d459b842..aea40c42b90e 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -5076,17 +5076,14 @@ static struct kern_feature_desc { }, }; =20 -bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id = feat_id) +bool feat_supported(struct kern_feature_cache *cache, enum kern_feature_= id feat_id) { struct kern_feature_desc *feat =3D &feature_probes[feat_id]; - struct kern_feature_cache *cache =3D &feature_cache; int ret; =20 - if (obj && obj->gen_loader) - /* To generate loader program assume the latest kernel - * to avoid doing extra prog_load, map_create syscalls. - */ - return true; + /* assume global feature cache, unless custom one is provided */ + if (!cache) + cache =3D &feature_cache; =20 if (READ_ONCE(cache->res[feat_id]) =3D=3D FEAT_UNKNOWN) { ret =3D feat->probe(); @@ -5103,6 +5100,17 @@ bool kernel_supports(const struct bpf_object *obj,= enum kern_feature_id feat_id) return READ_ONCE(cache->res[feat_id]) =3D=3D FEAT_SUPPORTED; } =20 +bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id = feat_id) +{ + if (obj && obj->gen_loader) + /* To generate loader program assume the latest kernel + * to avoid doing extra prog_load, map_create syscalls. + */ + return true; + + return feat_supported(NULL, feat_id); +} + static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd) { struct bpf_map_info map_info; diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_inter= nal.h index b5d334754e5d..754a432335e4 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -360,8 +360,11 @@ enum kern_feature_id { __FEAT_CNT, }; =20 -int probe_memcg_account(void); +struct kern_feature_cache; +bool feat_supported(struct kern_feature_cache *cache, enum kern_feature_= id feat_id); bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id = feat_id); + +int probe_memcg_account(void); int bump_rlimit_memlock(void); =20 int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz); --=20 2.34.1