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 3A30219F48D; Mon, 27 Oct 2025 18:49:50 +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=1761590991; cv=none; b=nbnpe26kvZmefVNQVIc/NPe69EL4+i+zkq1t/OQRuLn3FYN+LAH7M8Fem55MwqEWfdXVoANlO6I1EvNofru18/KPVdK37i4R47z+KidlQMljksCs8+cU4U00P2ZdyOB9ciDhEfnKlBNTUI7H8d/Jr7KxH1QABBei8eLlehenN0c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761590991; c=relaxed/simple; bh=AeQaph7P9o29sBwaHrJJZpp3YDHCPS42MO38139VTag=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iGCzkI4OK87BWBjdFlDPQ4OSVspxr1CMevBADqmvh5OVla/gbFNseDof3LXTyiJhIVUFw3IScX87qsbUS63mgaf9+YsxFlHv9D2xfKG6DdpFK4eJJq/moI/YdO16qH9nrE7fkQSmydH9frwm8nGXvx2zCOmVO0b9ob0ueAF7uHc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=N5gPRZYJ; 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="N5gPRZYJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 230BCC4CEF1; Mon, 27 Oct 2025 18:49:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761590990; bh=AeQaph7P9o29sBwaHrJJZpp3YDHCPS42MO38139VTag=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N5gPRZYJsaNu1W5lpP0dMsViIjFo2a2ixK0M/Q/u2VY3jtdAIw/AOaqA87hQUO4T2 8oVmtQbQmlH2DaXg9W4Hv4Ubp+6eFIsNOZ1EZVQttfz/cf4uCAToFSUmyGTtOMrE2h C7+okncdLy1Roj32f8SSXH16FkFs5vpir+oZCW5c= 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 5.10 025/332] libbpf: Fix reuse of DEVMAP Date: Mon, 27 Oct 2025 19:31:18 +0100 Message-ID: <20251027183525.285977528@linuxfoundation.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251027183524.611456697@linuxfoundation.org> References: <20251027183524.611456697@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-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 f65e03e7cf944..4c6902c7bdff7 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4091,6 +4091,16 @@ 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