From patchwork Wed Jan 24 02:21:18 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 13528393 X-Patchwork-Delegate: paul@paul-moore.com Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D050B1774E; Wed, 24 Jan 2024 02:22:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706062968; cv=none; b=lEIwWWNaLsJ9cu1mqelO/XZWiv9tFLD/CIkn+jw7Z2EMSYmUL2xIK06pGQQ8yiJzIdRN9QaAAWAOzf20E1YvrJoHNzoOMtCYL2TUsjmbtpl/P56a7xl6FzEQBYsCRw5Md3vQNSud0JhyB0KQmTC+rm8xg6vo58nqHLTZyrbZgGU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706062968; c=relaxed/simple; bh=y3pUuQBVW98ypG/drn9fCLTGqekiYVpWE5d/7A4fYyg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=BskKqnTY5uFfHGlS9KXJxEbjJR34Gu+WFc4n9VVD8eSg9fIrawEqZ4RU+pkdFbNwvU4JGR++6NQYPPsMzZ9PU/jQ6oeWVyJvA396n1znP2q69yD2PX+4Nlnzd/fpITG6a4CtiKRl6znfOQyhuVTkA/69XisPca796bEJS7ybZ/8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eXpXM8E5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eXpXM8E5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BBBDC433F1; Wed, 24 Jan 2024 02:22:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706062968; bh=y3pUuQBVW98ypG/drn9fCLTGqekiYVpWE5d/7A4fYyg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eXpXM8E5E/LG7Zg8jsW8mKpMW3o/ag97+ZGjAUw/WR/LdpdWaVKnw4eWd78lRWUqQ sbsOVip+10hvpLYDl36dpsUWqiDlmlSbkT9CPdbigSVTqtkwbDl0vI5f4QH4Xo1JPG uXq+K/9hg16t1l3PzTZJOikz3YEaEi33xCXlt5eWVFp/SBmgPynTb3K3P0Nl/lGhCj AA/fiHW4DLYBNElbTUcynAQ95eZCnKl+247ThlvNTpEHNwQ3tUjXPscB+heiZ7+qpC p5CtziMZyQoIonAHqx6EQebx+wWX8/XXd005xwHLT9Zz1zOOUgXdI2fYkBRYKeH2/X LpP3MZ2LWWiGQ== From: Andrii Nakryiko 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 Message-Id: <20240124022127.2379740-22-andrii@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240124022127.2379740-1-andrii@kernel.org> References: <20240124022127.2379740-1-andrii@kernel.org> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 Signed-off-by: Andrii Nakryiko --- 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)