From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 9 May 2018 01:04:38 +0000 From: "Luis R. Rodriguez" To: Matthew Wilcox , Tony Luck Cc: "Luis R. Rodriguez" , arnd@arndb.de, gregkh@linuxfoundation.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Fenghua Yu , linux-ia64@vger.kernel.org Subject: Re: [PATCH] mm: provide a fallback for PAGE_KERNEL_RO for architectures Message-ID: <20180509010438.GM27853@wotan.suse.de> References: <20180428001526.22475-1-mcgrof@kernel.org> <20180428031810.GA14566@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180428031810.GA14566@bombadil.infradead.org> Sender: owner-linux-mm@kvack.org List-ID: On Fri, Apr 27, 2018 at 08:18:10PM -0700, Matthew Wilcox wrote: > On Fri, Apr 27, 2018 at 05:15:26PM -0700, Luis R. Rodriguez wrote: > > Some architectures do not define PAGE_KERNEL_RO, best we can do > > for them is to provide a fallback onto PAGE_KERNEL. Remove the > > hack from the firmware loader and move it onto the asm-generic > > header, and document while at it the affected architectures > > which do not have a PAGE_KERNEL_RO: > > > > o alpha > > o ia64 > > o m68k > > o mips > > o sparc64 > > o sparc > > ia64 doesn't have it? > > *fx: riffles through architecture book* > > That seems like an oversight of the Linux port. Tony, Fenghua, any thoughts? Poke *Tony, Fenghua* ? > (also, Luis, maybe move the PAGE_KERNEL_EXEC fallback the same way you > moved the PAGE_KERNEL_RO fallback?) Done. Will queue in the generic PAGE_KERNEL_EXEC patch to my series. > --- >8 --- > > ia64: Add PAGE_KERNEL_RO and PAGE_KERNEL_EXEC > > The rest of the kernel was falling back to simple PAGE_KERNEL pages; using > PAGE_KERNEL_RO and PAGE_KERNEL_EXEC provide better protection against > unintended writes. > > Signed-off-by: Matthew Wilcox Nice, should I queue this into my series as well? Luis