From mboxrd@z Thu Jan 1 00:00:00 1970 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 C001E330B1B; Fri, 17 Oct 2025 15:46:13 +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=1760715973; cv=none; b=GKYPudhjMrHg8LMSK8tNKFf8VZhqWEcZakw48kL/ItwWfbNhC6e+pLZKrD3UgWz2ij8yGSTGI7jxdAR8Ui5PpRMNKjmVb5cP4CKGIZu6X9ErfOfE1pp6/z1FirYAxGxY5C8jOyjeXnhojPngj6vMWNIOxYF5uUqGU49xU8AcxpE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760715973; c=relaxed/simple; bh=rntNi5MerU1VNUz5Dp54ibXFiZQTt1r54WxOG/WgcnU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cYFyrjb948Fw/IWe+04r6bVohzinbwPBbaofJhdSjxWNgE1SJSEmk3LCFYRS56mfKsvWKZajGlHidJ78uBr70NDi3QKiQ/tklLYA8H5rLS9OBjqUXueDxH/7acwGAqSBeFbutDj28CfkO5ETXa760/J90oXeyDDLAtdJxrQf1kg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XqkA3dcS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="XqkA3dcS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A26EC4CEE7; Fri, 17 Oct 2025 15:46:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760715973; bh=rntNi5MerU1VNUz5Dp54ibXFiZQTt1r54WxOG/WgcnU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XqkA3dcSiMasqgkWWrWaKFd1SXyMkYPqBc+ZT8/C+PQhZDwFISexEjmclWRmVAXu9 FShBTJaquhAskCKw0UFdsrc0HcPJ6r0j2WCu4GhRa+hQg1GQgZ6VJKNCz+DWWM/j5h opco6xq3HeMh6OXlzZ+mAyXot5KxuhyIrsfpgedQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yureka Lilian , Andrii Nakryiko , Sasha Levin Subject: [PATCH 5.15 029/276] libbpf: Fix reuse of DEVMAP Date: Fri, 17 Oct 2025 16:52:02 +0200 Message-ID: <20251017145143.467458345@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251017145142.382145055@linuxfoundation.org> References: <20251017145142.382145055@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yureka Lilian [ Upstream commit 6c6b4146deb12d20f42490d5013f2043df942161 ] Previously, re-using pinned DEVMAP maps would always fail, because get_map_info on a DEVMAP always returns flags with BPF_F_RDONLY_PROG set, but BPF_F_RDONLY_PROG being set on a map during creation is invalid. Thus, ignore the BPF_F_RDONLY_PROG flag in the flags returned from get_map_info when checking for compatibility with an existing DEVMAP. The same problem is handled in a third-party ebpf library: - https://github.com/cilium/ebpf/issues/925 - https://github.com/cilium/ebpf/pull/930 Fixes: 0cdbb4b09a06 ("devmap: Allow map lookups from eBPF") Signed-off-by: Yureka Lilian Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250814180113.1245565-3-yuka@yuka.dev Signed-off-by: Sasha Levin --- tools/lib/bpf/libbpf.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 13dea519e59f2..d9589c92e05d2 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4485,6 +4485,16 @@ static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd) return false; } + /* + * bpf_get_map_info_by_fd() for DEVMAP will always return flags with + * BPF_F_RDONLY_PROG set, but it generally is not set at map creation time. + * Thus, ignore the BPF_F_RDONLY_PROG flag in the flags returned from + * bpf_get_map_info_by_fd() when checking for compatibility with an + * existing DEVMAP. + */ + if (map->def.type == BPF_MAP_TYPE_DEVMAP || map->def.type == BPF_MAP_TYPE_DEVMAP_HASH) + map_info.map_flags &= ~BPF_F_RDONLY_PROG; + return (map_info.type == map->def.type && map_info.key_size == map->def.key_size && map_info.value_size == map->def.value_size && -- 2.51.0