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 41D3830F814; Mon, 13 Oct 2025 15:21:18 +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=1760368879; cv=none; b=a6hPAvf83mfZIXIIN7vVvami0LDx/ZER84KDdLOqPEN3SBctWrVSt5TF4zToF8VHYsAfaHE5E9QsjkOTPQMO3AqnJdS5Xi+P8nMo2RVIKptgtWLOgiZlWPYQE8dRxE9iVJfyadIaX+gtfGOkQ+8hbg7KIi24Av0s2+1S52LJEnc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760368879; c=relaxed/simple; bh=BHtwnrP4GXEJbgsRepWwY0n2Z0P0DqGml6RaDxf1HVY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Vu2Aby2kszD/PFUv5gdo6S/Gd8JISihfZ0ki6++QkMds7Q3MJhPoaiEci8gdp1NeRGxYeu5SRoCAXsGco5+ceSoC0hlrSJTZ/Fuvb25bDbtG2CVJyaktqsFBmundk2TRF1+6ORdFiOl5/+wDxW+313YJ/AKTYV+ZlvgDocY2yKc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=RJOKketb; 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="RJOKketb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F489C116B1; Mon, 13 Oct 2025 15:21:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760368878; bh=BHtwnrP4GXEJbgsRepWwY0n2Z0P0DqGml6RaDxf1HVY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RJOKketbDlDsV76zzgyxAC8khonFe7opcvg81E04FtsU9bjQfnAGsr5msg/8+iM2H 7AAixwj4EXEVFT2CQOFpwANqiUw8myl4T0TTYmZaTbV+dW9rnI4FmrKC2yyuUPYex0 fOoQ+w+aor1302xXSmpG5Ydl51gM5iKWhqhEFgQs= 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 6.17 049/563] libbpf: Fix reuse of DEVMAP Date: Mon, 13 Oct 2025 16:38:30 +0200 Message-ID: <20251013144413.070335437@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251013144411.274874080@linuxfoundation.org> References: <20251013144411.274874080@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 6.17-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 8f5a81b672e1b..fe4fc5438678c 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -5093,6 +5093,16 @@ 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