From mboxrd@z Thu Jan 1 00:00:00 1970 From: gregkh@linuxfoundation.org (gregkh at linuxfoundation.org) Date: Mon, 17 Jul 2017 16:18:40 +0200 Subject: [PATCH v3] drivers/char: kmem: disable on arm64 In-Reply-To: References: <1497941940-2699-1-git-send-email-ard.biesheuvel@linaro.org> Message-ID: <20170717141840.GA16198@kroah.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Jun 20, 2017 at 01:20:49PM +0200, Ard Biesheuvel wrote: > On 20 June 2017 at 08:59, Ard Biesheuvel wrote: > > As it turns out, arm64 deviates from other architectures in the way it > > maps the VMALLOC region: on most (all?) other architectures, it resides > > strictly above the kernel's direct mapping of DRAM, but on arm64, this > > is the other way around. For instance, for a 48-bit VA configuration, > > we have > > > > modules : 0xffff000000000000 - 0xffff000008000000 ( 128 MB) > > vmalloc : 0xffff000008000000 - 0xffff7dffbfff0000 (129022 GB) > > ... > > vmemmap : 0xffff7e0000000000 - 0xffff800000000000 ( 2048 GB maximum) > > 0xffff7e0000000000 - 0xffff7e0003ff0000 ( 63 MB actual) > > memory : 0xffff800000000000 - 0xffff8000ffc00000 ( 4092 MB) > > > > This has mostly gone unnoticed until now, but it does appear that it > > breaks an assumption in the kcore > > s/kcore/kmem/ v4? :)