From mboxrd@z Thu Jan  1 00:00:00 1970
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 18 Feb 2022 01:50:36 +0000
Subject: Re: [PATCH v2 00/18] clean up asm/uaccess.h, kill set_fs for good
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 <00496df2-f9f2-2547-3ca3-7989e4713d6b@csgroup.eu>
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To: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Arnd Bergmann <arnd@kernel.org>, Linus Torvalds <torvalds@linux-foundation.org>, Christoph Hellwig <hch@lst.de>, "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>, "linux-mm@kvack.org" <linux-mm@kvack.org>, "linux-api@vger.kernel.org" <linux-api@vger.kernel.org>, "arnd@arndb.de" <arnd@arndb.de>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "mark.rutland@arm.com" <mark.rutland@arm.com>, "dalias@libc.org" <dalias@libc.org>, "linux-ia64@vger.kernel.org" <linux-ia64@vger.kernel.org>, "linux-sh@vger.kernel.org" <linux-sh@vger.kernel.org>, "peterz@infradead.org" <peterz@infradead.org>, "jcmvbkbc@gmail.com" <jcmvbkbc@gmail.com>, "guoren@kernel.org" <guoren@kernel.org>, "sparclinux@vger.kernel.org" <sparclinux@vger.kernel.org>, "linux-hexagon@vger.kernel.org" <linux-hexagon@vger.kernel.org>, "linux-riscv@lists.infradead.org" <linux-riscv@lists.infradead.org>, "will@kernel.org" <will@kernel.org>, "ardb@kernel.org" <ardb@kernel.org>, "linux-s390@vger.kernel.org" <linux-s390@vger.kernel.org>, "bcain@codeaurora.org" <bcain@codeaurora.org>, "deller@gmx.de" <deller@gmx.de>, "x86@kernel.org" <x86@kernel.org>, "linux@armlinux.org.uk" <linux@armlinux.org.uk>, "linux-csky@vger.kernel.org" <linux-csky@vger.kernel.org>, "mingo@redhat.com" <mingo@redhat.com>, "geert@linux-m68k.org" <geert@linux-m68k.org>, "linux-snps-arc@lists.infradead.org" <linux-snps-arc@lists.infradead.org>, "linux-xtensa@linux-xtensa.org" <linux-xtensa@linux-xtensa.org>, "hca@linux.ibm.com" <hca@linux.ibm.com>, "linux-alpha@vger.kernel.org" <linux-alpha@vger.kernel.org>, "linux-um@lists.infradead.org" <linux-um@lists.infradead.org>, "linux-m68k@lists.linux-m68k.org" <linux-m68k@lists.linux-m68k.org>, "openrisc@lists.librecores.org" <openrisc@lists.librecores.org>, "green.hu@gmail.com" <green.hu@gmail.com>, "shorne@gmail.com" <shorne@gmail.com>, "monstr@monstr.eu" <monstr@monstr.eu>, "tsbogend@alpha.franken.de" <tsbogend@alpha.franken.de>, "linux-parisc@vger.kernel.org" <linux-parisc@vger.kernel.org>, "nickhu@andestech.com" <nickhu@andestech.com>, "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>, "dinguyen@kernel.org" <dinguyen@kernel.org>, "ebiederm@xmission.com" <ebiederm@xmission.com>, "richard@nod.at" <richard@nod.at>, "akpm@linux-foundation.org" <akpm@linux-foundation.org>, "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>, "davem@davemloft.net" <davem@davemloft.net>

On Thu, Feb 17, 2022 at 07:20:11AM +0000, Christophe Leroy wrote:

> And we have also 
> user_access_begin()/user_read_access_begin()/user_write_access_begin() 
> which call access_ok() then do the real work. Could be made generic with 
> call to some arch specific __user_access_begin() and friends after the 
> access_ok() and eventually the might_fault().

Not a good idea, considering the fact that we do not want to invite
uses of "faster" variants...