From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3AF902F546D for ; Wed, 15 Jul 2026 13:44:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784123076; cv=none; b=gr64FC0yX3QcK4/6NUVlyxC5hrJmqqqJfMi8IcuNieW6507eUqHTbFmrjdukhboeRbqx5E3c7wNl+SPmg0GU2WZ9Fn/8FvLC/HkLjJs5vI30e8G3ZC3kANaANGVxz3BP9g7gT75UdbHpS5lpe872jBFklbrbq88Wgl6OBs/iq6A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784123076; c=relaxed/simple; bh=vshyrowR56fkQy5Oson6JIhpctTXrAQw8QCv0lr+oNk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=LtaFqFyBmIN3AwJe4VY2LKyjMy1JGHHBR0yx4I7Na7VjXZPAfC7A7djjbIjxLuhJVgl5aH1svzZZK7WQ6DgnLSSLvkVtufWWgZv+60hVaxC9jxcpxDU1dYYNf+muTRP6+48XzUIjfxMENVwM3U2FxL17NRkeq6yBFWglMEDtj+E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AxyFpBfK; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AxyFpBfK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 318791F000E9; Wed, 15 Jul 2026 13:44:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784123074; bh=9NxeIMCQLUALFB3p9cZLEOe/ZyRxY6DXqkHXVUWxObw=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=AxyFpBfKq5QOyikTyDSfvnH6Lvyt7riHpVkft1Wf5lTr1Omc9BJjA3kSwGI5RLKoU ehCwOZjqLog2K13vsrhH0E/+d5D6ai59yo72ODnyXor0lGMl9gNx8Z0u1G9Hb+LsJe yJNZ2sbm13kY7qkdAepORJyOpMC0rsG5v7VL4Az7YDbsg3M1rcbX3F47FcZ6ZCzK70 XXLAeoiJnCPqwxn0Vk0A7RrvpO6YmYF4DiCC9UZTJ2g8kuBreFke3CuK3RFsJpuF8i IfHx9DcCEXpu4KX9lR5fs+4tzVAp9YCr09yFH0LtlO+1aNSm7LBQL8+n5qlfsmL8bR 3JVKmyhAjPp+w== Date: Wed, 15 Jul 2026 16:44:28 +0300 From: Mike Rapoport To: "David Hildenbrand (Arm)" Cc: Brendan Jackman , Andrew Morton , Brendan Jackman , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/secretmem: disable under HIGHMEM Message-ID: References: <20260703-secretmem-highmem-v1-1-30d5ff944664@google.com> <20260704192603.40aa80cf9242b77aa75e8d8d@linux-foundation.org> <503aee9e-97fc-4889-a379-3c0a5d140554@kernel.org> <7e7f20de-c43d-40f7-82d3-8d05ceb3656b@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@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: <7e7f20de-c43d-40f7-82d3-8d05ceb3656b@kernel.org> On Wed, Jul 15, 2026 at 02:31:08PM +0200, David Hildenbrand (Arm) wrote: > On 7/15/26 13:33, Mike Rapoport wrote: > > On Wed, Jul 15, 2026 at 11:22:33AM +0000, Brendan Jackman wrote: > >> On Mon Jul 6, 2026 at 8:42 AM UTC, David Hildenbrand (Arm) wrote: > >>> > >>> Right. > >>> > >>> > >>> We could even limit it to 64BIT ;) > >> > >> I fear this in limbo, we have quite a wide range of opinions from "fix > >> the broken configuration" all the way to "disable secretmem completely on > >> 32bit". I'm not passionately committed to any one answer but I do think > >> we need to pick something. > >> > >> Mike's position seems to be roughly "in the middle" of the spectrum, and > > > > Right :) > > Supporting 32-bit without HIGHMEM is easy, so I don't think we should limit > > it to 64BIT at this point. > > You mean > > diff --git a/mm/secretmem.c b/mm/secretmem.c > index 4877c262cb1f6..d29865075b6ea 100644 > --- a/mm/secretmem.c > +++ b/mm/secretmem.c > @@ -202,7 +202,7 @@ static struct file *secretmem_file_create(unsigned long flags) > if (IS_ERR(file)) > goto err_free_inode; > > - mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER); > + mapping_set_gfp_mask(inode->i_mapping, GFP_USER); > mapping_set_unevictable(inode->i_mapping); > > inode->i_op = &secretmem_iops; > > > then? No, I mean what Brendan's patch did: config SECRETMEM default y bool "Enable memfd_secret() system call" if EXPERT - depends on ARCH_HAS_SET_DIRECT_MAP + depends on ARCH_HAS_SET_DIRECT_MAP && !HIGHMEM We can change gfp_mask as well for the sake of pedancy > -- > Cheers, > > David -- Sincerely yours, Mike.