From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stafford Horne Date: Tue, 18 Jan 2022 20:48:17 +0900 Subject: [OpenRISC] architectures that still need to remove set_fs() In-Reply-To: <20220118074836.GA20994@lst.de> References: <20220118074836.GA20994@lst.de> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: openrisc@lists.librecores.org Hi, On Tue, Jan 18, 2022 at 08:48:36AM +0100, Christoph Hellwig wrote: > Hi all, > > you are in this list because your architecture still implements and > uses address space overrides using set_fs(), which are deprecated and > have been removed from all mainstream architecture ports. To help > cleanup the core kernel it would be great to make progress on removing > set_fs entirely. > > The following steps are required: > > (1) implement the __get_kernel_nofault and __put_kernel_nofault > helper to access kernel memory without page faults, replacing > the get/put_user under set_fs(KERNEL_DS) abuse. Mips has a good > example for a trivial implementation for architectures that use > a common address space in commit 04324f44cb69 Also see commit 08ee3a009f49a which is preparation for removing set_fs/get_fs this commit implements __get_kernel_nofault/__put_kernel_nofault for mips. > (2) remove any architecture specific use of such constructs. This > only affects ia64 and sh. > (3) stop selecting the SET_FS and remove all the set_fs-related > infrastructure. The above mips commit is a good guide once again. > > Thanks! I will look into this for OpenRISC. -Stafford