<cmetcalf@xxxxxxxxxxxx>,"Paul E . McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>,Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>,Christopher Li <sparse@xxxxxxxxxxx>,Dou Liyang <douly.fnst@xxxxxxxxxxxxxx>,Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>,Daniel Borkmann <daniel@xxxxxxxxxxxxx>,Markus Trippelsdorf <markus@xxxxxxxxxxxxxxx>,Peter Foley <pefoley2@xxxxxxxxxxx>,Steven Rostedt <rostedt@xxxxxxxxxxx>,Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>,Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>,Catalin Marinas <catalin.marinas@xxxxxxx>,Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>,Michal Hocko <mhocko@xxxxxxxx>,Rob Landley <rob@xxxxxxxxxxx>,Jiri Kosina <jkosina@xxxxxxx>,"H . J . Lu" <hjl.tools@xxxxxxxxx>,Paul Bolle <pebolle@xxxxxxxxxx>,Baoquan He <bhe@xxxxxxxxxx>,Daniel Micay <danielmicay@xxxxxxxxx>,the arch/x86 maintainers <x86@xxxxxxxxxx>,linux-crypto@xxxxxxxxxxxxxxx,LKML <linux-kernel@xxxxxxxxxxxxxxx>,xen-devel@xxxxxxxxxxxxxxxxxxxx,kvm list <kvm@xxxxxxxxxxxxxxx>,Linux PM list <linux-pm@xxxxxxxxxxxxxxx>,linux-arch <linux-arch@xxxxxxxxxxxxxxx>,linux-sparse@xxxxxxxxxxxxxxx,Kernel Hardening <kernel-hardening@xxxxxxxxxxxxxxxxxx> From: hpa@xxxxxxxxx Message-ID: <0EF6FAAA-A99C-4F0D-9E4A-AD25E93957FB@xxxxxxxxx> On July 19, 2017 4:25:56 PM PDT, Thomas Garnier <thgarnie@xxxxxxxxxx> wrote: >On Wed, Jul 19, 2017 at 4:08 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote: >> On 07/19/17 15:47, Thomas Garnier wrote: >>> On Wed, Jul 19, 2017 at 3:33 PM, H. Peter Anvin <hpa@xxxxxxxxx> >wrote: >>>> On 07/18/17 15:33, Thomas Garnier wrote: >>>>> The x86 relocation tool generates a list of 32-bit signed >integers. There >>>>> was no need to use 64-bit integers because all addresses where >above the 2G >>>>> top of the memory. >>>>> >>>>> This change add a large-reloc option to generate 64-bit unsigned >integers. >>>>> It can be used when the kernel plan to go below the top 2G and >32-bit >>>>> integers are not enough. >>>> >>>> Why on Earth? This would only be necessary if the *kernel itself* >was >>>> more than 2G, which isn't going to happen for the forseeable >future. >>> >>> Because the relocation integer is an absolute address, not an offset >>> in the binary. Next iteration, I can try using a 32-bit offset for >>> everyone. >> >> It is an absolute address *as the kernel was originally linked*, for >> obvious reasons. > >Sure when the kernel was just above 0xffffffff80000000, it doesn't >work when it goes down to 0xffffffff00000000. That's why using an >offset might make more sense in general. > >> >> -hpa >> What is the motivation for changing the pre linked address at all? -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
