On Mon, Jun 13, 2016 at 01:23:29PM -0700, Kees Cook wrote: > On Wed, Jun 8, 2016 at 4:11 PM, Kees Cook <[email protected]> wrote: > > The _etext position is defined to be the end of the kernel text code, > > and should not include any part of the data segments. This interferes > > with things that might check memory ranges and expect executable code > > up to _etext. > > > > Signed-off-by: Kees Cook <[email protected]> > > Can someone give this an Ack? I'd like to land it as it is a > prerequisite to some usercopy hardening work I'm doing.
We use _etext to place the end of the "kernel code" resource in /proc/iomem, and init_mm.end_code. I don't think anything makes use of init_mm.end_code, but I'm more worried about the resource. Currently, because of where _etext is placed, "kernel code" covers the read-only data and other read-only sections as well - I don't know whether we need to preserve that, but this change has a side effect of changing that. Maybe we also need a "kernel rodata" resource? -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.
