From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 425591BF333 for ; Tue, 1 Oct 2024 11:15:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727781353; cv=none; b=LazCuERjav0onUbqLtwrknRR5bvfq1cf40W6BtMRhyzxk+Q5KvKCPlAXHS2+IxviP6NQrhc6Ry+fvSGPqzZyP+89Fb8oy7j0+L65DPCtQRfkBU13RxY5xNfkglY00bF+DNoUn99vFQXvQVgRrgmTMNOAqIYvaEnxnQFCcNsva1Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727781353; c=relaxed/simple; bh=75htphhgA085Ed8d9ndrShWFVyE9Crb9bXv3CKbhqHY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PV6IFa4j5j7ZUfgdOiJ0XaBCWkVMq8VPBCLSO3cEkJzEUaPPJEhQKrOx0MUPCcll01GxYlHJ5UMBtmk3nh9YcEeMUbQjPmwz8Mp5j1p9LsTQfo0GVncxmHDEB6WJElyx7wOwlA1ID/N2Mox6ZbKYWfO4DdWd1G7pZW06QyWGqJE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=WPTQA4Xw; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WPTQA4Xw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1727781351; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=NIVZImqQH49iyAAF5H9hztBo3T/3c+Ny3Vzoq1Av9pM=; b=WPTQA4XwWPEGEn0T4upx7KKZDgkjIAwUTajD0DAId9AS9VMZDohfaXOmkqGqjOBfEI82q9 6dPBv58FdIv7nYHTbJIwugnxCRpecP3j5TLO32kuImS4VjvbM33FKcduXuDiJPxO2S6oPr b/xJEwqwE5g0QHqjvAthtvrvTZAZMmM= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-584-gpYJf8bhNRKEkSMww0yRxw-1; Tue, 01 Oct 2024 07:15:45 -0400 X-MC-Unique: gpYJf8bhNRKEkSMww0yRxw-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (unknown [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 68422194511F; Tue, 1 Oct 2024 11:15:43 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.225.88]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id D20FF1944B21; Tue, 1 Oct 2024 11:15:31 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Tue, 1 Oct 2024 13:15:29 +0200 (CEST) Date: Tue, 1 Oct 2024 13:15:17 +0200 From: Oleg Nesterov To: Stas Sergeev Cc: linux-kernel@vger.kernel.org, Alexander Viro , Christian Brauner , Jan Kara , Jens Axboe , Andrew Morton , Catalin Marinas , Florent Revest , Kees Cook , Palmer Dabbelt , Charlie Jenkins , Benjamin Gray , Helge Deller , Zev Weiss , Samuel Holland , linux-fsdevel@vger.kernel.org, Eric Biederman , Andy Lutomirski , Josh Triplett Subject: Re: [PATCH v3] add group restriction bitmap Message-ID: <20241001111516.GA23907@redhat.com> References: <20240930195958.389922-1-stsp2@yandex.ru> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240930195958.389922-1-stsp2@yandex.ru> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 I can't comment the intent, just some nits about implementation. On 09/30, Stas Sergeev wrote: > > struct group_info { > refcount_t usage; > + unsigned int restrict_bitmap; Why not unsigned long? > int groups_search(const struct group_info *group_info, kgid_t grp) > { > unsigned int left, right; > @@ -105,7 +108,7 @@ int groups_search(const struct group_info *group_info, kgid_t grp) > else if (gid_lt(grp, group_info->gid[mid])) > right = mid; > else > - return 1; > + return mid + 1; Suppose we change groups_search() --- a/kernel/groups.c +++ b/kernel/groups.c @@ -104,8 +104,11 @@ int groups_search(const struct group_info *group_info, kgid_t grp) left = mid + 1; else if (gid_lt(grp, group_info->gid[mid])) right = mid; - else - return 1; + else { + bool r = mid < BITS_PER_LONG && + test_bit(mid, &group_info->restrict_bitmap); + return r ? -1 : 1; + } } return 0; } so that it returns, say, -1 if the found grp is restricted. Then everything else can be greatly simplified, afaics... Oleg.