From mboxrd@z Thu Jan  1 00:00:00 1970
From: Heiko Carstens <hca@linux.ibm.com>
Date: Tue, 18 Oct 2022 07:59:14 +0000
Subject: Re: [PATCH] mm: remove kern_addr_valid() completely
Message-Id: <Y05d5ii/2OqYLqa0@osiris>
List-Id: <linux-ia64.vger.kernel.org>
References: <20221018074014.185687-1-wangkefeng.wang@huawei.com>
In-Reply-To: <20221018074014.185687-1-wangkefeng.wang@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, linux-fsdevel@vger.kernel.org, Richard Henderson <richard.henderson@linaro.org>, Ivan Kokshaysky <ink@jurassic.park.msu.ru>, Matt Turner <mattst88@gmail.com>, Vineet Gupta <vgupta@kernel.org>, Russell King <linux@armlinux.org.uk>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Guo Ren <guoren@kernel.org>, Huacai Chen <chenhuacai@kernel.org>, WANG Xuerui <kernel@xen0n.name>, Geert Uytterhoeven <geert@linux-m68k.org>, Greg Ungerer <gerg@linux-m68k.org>, Michal Simek <monstr@monstr.eu>, Thomas Bogendoerfer <tsbogend@alpha.franken.de>, Dinh Nguyen <dinguyen@kernel.org>, Jonas Bonn <jonas@southpole.se>, Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>, Stafford Horne <shorne@gmail.com>, "James E . J . Bottomley" <James.Bottomley@hansenpartnership.com>, Helge Deller <deller@gmx.de>, Michael Ellerman <mpe@ellerman.id.au>, Nicholas Piggin <npiggin@gmail.com>, Christophe Leroy <christophe.leroy@csgroup.eu>, Paul Walmsley <paul.walmsley@sifive.com>, Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>, Vasily Gorbik <gor@linux.ibm.com>, Alexander Gordeev <agordeev@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, Sven Schnelle <svens@linux.ibm.com>, Yoshinori Sato <ysato@users.sourceforge.jp>, Rich Felker <dalias@libc.org>, "David S . Miller" <davem@davemloft.net>, Richard Weinberger <richard@nod.at>, Anton Ivanov <anton.ivanov@cambridgegreys.com>, Johannes Berg <johannes@sipsolutions.net>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>, Andy Lutomirski <luto@kernel.org>, Peter Zijlstra <peterz@infradead.org>, Chris Zankel <chris@zankel.net>, Max Filippov <jcmvbkbc@gmail.com>

On Tue, Oct 18, 2022 at 03:40:14PM +0800, Kefeng Wang wrote:
> Most architectures(except arm64/x86/sparc) simply return 1 for
> kern_addr_valid(), which is only used in read_kcore(), and it
> calls copy_from_kernel_nofault() which could check whether the
> address is a valid kernel address, so no need kern_addr_valid(),
> let's remove unneeded kern_addr_valid() completely.
> 
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
...
>  arch/s390/include/asm/pgtable.h           |  2 -

For s390:
Acked-by: Heiko Carstens <hca@linux.ibm.com>