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From: Andrii Nakryiko <andrii@kernel.org>
To: bpf@vger.kernel.org, netdev@vger.kernel.org, paul@paul-moore.com,
	brauner@kernel.org
Cc: torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org,
	linux-security-module@vger.kernel.org, kernel-team@meta.com
Subject: [PATCH v2 bpf-next 21/30] libbpf: split feature detectors definitions from cached results
Date: Tue, 23 Jan 2024 18:21:18 -0800	[thread overview]
Message-ID: <20240124022127.2379740-22-andrii@kernel.org> (raw)
In-Reply-To: <20240124022127.2379740-1-andrii@kernel.org>

Split a list of supported feature detectors with their corresponding
callbacks from actual cached supported/missing values. This will allow
to have more flexible per-token or per-object feature detectors in
subsequent refactorings.

Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 tools/lib/bpf/libbpf.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index b8b00da62907..4fc9dfd28f61 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -4944,12 +4944,17 @@ enum kern_feature_result {
 	FEAT_MISSING = 2,
 };
 
+struct kern_feature_cache {
+	enum kern_feature_result res[__FEAT_CNT];
+};
+
 typedef int (*feature_probe_fn)(void);
 
+static struct kern_feature_cache feature_cache;
+
 static struct kern_feature_desc {
 	const char *desc;
 	feature_probe_fn probe;
-	enum kern_feature_result res;
 } feature_probes[__FEAT_CNT] = {
 	[FEAT_PROG_NAME] = {
 		"BPF program name", probe_kern_prog_name,
@@ -5017,6 +5022,7 @@ static struct kern_feature_desc {
 bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id)
 {
 	struct kern_feature_desc *feat = &feature_probes[feat_id];
+	struct kern_feature_cache *cache = &feature_cache;
 	int ret;
 
 	if (obj && obj->gen_loader)
@@ -5025,19 +5031,19 @@ bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id)
 		 */
 		return true;
 
-	if (READ_ONCE(feat->res) == FEAT_UNKNOWN) {
+	if (READ_ONCE(cache->res[feat_id]) == FEAT_UNKNOWN) {
 		ret = feat->probe();
 		if (ret > 0) {
-			WRITE_ONCE(feat->res, FEAT_SUPPORTED);
+			WRITE_ONCE(cache->res[feat_id], FEAT_SUPPORTED);
 		} else if (ret == 0) {
-			WRITE_ONCE(feat->res, FEAT_MISSING);
+			WRITE_ONCE(cache->res[feat_id], FEAT_MISSING);
 		} else {
 			pr_warn("Detection of kernel %s support failed: %d\n", feat->desc, ret);
-			WRITE_ONCE(feat->res, FEAT_MISSING);
+			WRITE_ONCE(cache->res[feat_id], FEAT_MISSING);
 		}
 	}
 
-	return READ_ONCE(feat->res) == FEAT_SUPPORTED;
+	return READ_ONCE(cache->res[feat_id]) == FEAT_SUPPORTED;
 }
 
 static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd)
-- 
2.34.1


  parent reply	other threads:[~2024-01-24  2:22 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-24  2:20 [PATCH v2 bpf-next 00/30] BPF token Andrii Nakryiko
2024-01-24  2:20 ` [PATCH v2 bpf-next 01/30] bpf: align CAP_NET_ADMIN checks with bpf_capable() approach Andrii Nakryiko
2024-01-24  2:20 ` [PATCH v2 bpf-next 02/30] bpf: add BPF token delegation mount options to BPF FS Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 03/30] bpf: introduce BPF token object Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 04/30] bpf: add BPF token support to BPF_MAP_CREATE command Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 05/30] bpf: add BPF token support to BPF_BTF_LOAD command Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 06/30] bpf: add BPF token support to BPF_PROG_LOAD command Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 07/30] bpf: take into account BPF token when fetching helper protos Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 08/30] bpf: consistently use BPF token throughout BPF verifier logic Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 09/30] bpf,lsm: refactor bpf_prog_alloc/bpf_prog_free LSM hooks Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 10/30] bpf,lsm: refactor bpf_map_alloc/bpf_map_free " Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 11/30] bpf,lsm: add BPF token " Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 12/30] libbpf: add bpf_token_create() API Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 13/30] libbpf: add BPF token support to bpf_map_create() API Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 14/30] libbpf: add BPF token support to bpf_btf_load() API Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 15/30] libbpf: add BPF token support to bpf_prog_load() API Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 16/30] selftests/bpf: add BPF token-enabled tests Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 17/30] bpf,selinux: allocate bpf_security_struct per BPF token Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 18/30] bpf: fail BPF_TOKEN_CREATE if no delegation option was set on BPF FS Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 19/30] bpf: support symbolic BPF FS delegation mount options Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 20/30] selftests/bpf: utilize string values for delegate_xxx " Andrii Nakryiko
2024-01-24  2:21 ` Andrii Nakryiko [this message]
2024-01-24  2:21 ` [PATCH v2 bpf-next 22/30] libbpf: further decouple feature checking logic from bpf_object Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 23/30] libbpf: move feature detection code into its own file Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 24/30] libbpf: wire up token_fd into feature probing logic Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 25/30] libbpf: wire up BPF token support at BPF object level Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 26/30] selftests/bpf: add BPF object loading tests with explicit token passing Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 27/30] selftests/bpf: add tests for BPF object load with implicit token Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 28/30] libbpf: support BPF token path setting through LIBBPF_BPF_TOKEN_PATH envvar Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 29/30] selftests/bpf: add tests for " Andrii Nakryiko
2024-01-24  2:21 ` [PATCH v2 bpf-next 30/30] selftests/bpf: incorporate LSM policy to token-based tests Andrii Nakryiko
2024-01-25  0:10 ` [PATCH v2 bpf-next 00/30] BPF token patchwork-bot+netdevbpf

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