Re: [PATCH v3 3/9] efi/libstub: Remove .note.gnu.property
From: Ard Biesheuvel <ardb@kernel.org>
Date: 2020-06-24 15:48:56
Also in:
linux-arch, linux-efi, lkml
On Wed, 24 Jun 2020 at 17:45, Kees Cook [off-list ref] wrote:
On Wed, Jun 24, 2020 at 05:31:06PM +0200, Ard Biesheuvel wrote:quoted
On Wed, 24 Jun 2020 at 17:21, Kees Cook [off-list ref] wrote:quoted
On Wed, Jun 24, 2020 at 12:46:32PM +0200, Ard Biesheuvel wrote:quoted
I'm not sure if there is a point to having PAC and/or BTI in the EFI stub, given that it runs under the control of the firmware, with its memory mappings and PAC configuration etc.Is BTI being ignored when the firmware runs?Given that it requires the 'guarded' attribute to be set in the page tables, and the fact that the UEFI spec does not require it for executables that it invokes, nor describes any means of annotating such executables as having been built with BTI annotations, I think we can safely assume that the EFI stub will execute with BTI disabled in the foreseeable future.yaaaaaay. *sigh* How long until EFI catches up? That said, BTI shouldn't _hurt_, right? If EFI ever decides to enable it, we'll be ready?
Sure. Although I anticipate that we'll need to set some flag in the PE/COFF header to enable it, and so any BTI opcodes we emit without that will never take effect in practice. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel