In order to be able to read from and write to model-specific registers,
two new modules are added. They are i386 specific, as the cpuid module.
rdmsr module registers the command rdmsr that allows reading from a MSR.
wrmsr module registers the command wrmsr that allows writing to a MSR.
wrmsr module is disabled if UEFI secure boot is enabled.
Please note that on SMP systems, interacting with a MSR that has a scope
per hardware thread, implies that the value only applies to the
particular cpu/core/thread that ran the command.
Also, if you specify a reserved or unimplemented MSR address, it will
cause a general protection exception (which is not currently being
handled) and the system will reboot.
Signed-off-by: Jesús Diéguez Fernández <jesusdf@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
We now have signature check logic in grub which allows us to treat
files differently depending on their file type.
Treat a loaded device tree like an overlayed ACPI table.
Both describe hardware, so I suppose their threat level is the same.
Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
The value of tpm_handle changes between successive calls to grub_tpm_handle_find(),
as instead of simply copying the stored pointer we end up taking the address of
said pointer when using the cached value of grub_tpm_handle.
This causes grub_efi_open_protocol() to return a nullptr in grub_tpm2_execute()
and grub_tpm2_log_event(). Said nullptr goes unchecked and
efi_call_5(tpm->hash_log_extend_event,...) ends up jumping to 0x0, Qemu crashes
once video ROM is reached at 0xb0000.
This patch seems to do the trick of fixing that bug, but we should also ensure
that all calls to grub_efi_open_protocol() are checked so that we don't start
executing low memory.
Signed-off-by: Max Tottenham <mtottenh@akamai.com>
Reviewed-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Add support for performing basic TPM measurements. Right now this only
supports extending PCRs statically and only on UEFI. In future we might
want to have some sort of mechanism for choosing which events get logged
to which PCRs, but this seems like a good default policy and we can wait
to see whether anyone has a use case before adding more complexity.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This module provides shim lock verification for various kernels
if UEFI secure boot is enabled on a machine.
It is recommended to put this module into GRUB2 standalone image
(avoid putting iorw and memrw modules into it; they are disallowed
if UEFI secure boot is enabled). However, it is also possible to use
it as a normal module. Though such configurations are more fragile
and less secure due to various limitations.
If the module is loaded and UEFI secure boot is enabled then:
- module itself cannot be unloaded (persistent module),
- the iorw and memrw modules cannot be loaded,
- if the iorw and memrw modules are loaded then
machine boot is disabled,
- GRUB2 defers modules and ACPI tables verification to
other verifiers.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Let's provide file type info to the I/O layer. This way verifiers
framework and its users will be able to differentiate files and verify
only required ones.
This is preparatory patch.
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
when protocols_per_handle returns error, we can't use the pointers we
passed to it, and that includes trusting num_protocols.
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The getenv code was mishandling the conversion of binary to hex. Grub's
sprintf() doesn't seem to support the full set of format conversions, so
fix this in the nasty way.
PIT isn't available on some of new hardware including Hyper-V. So
use pmtimer for calibration. Moreover pmtimer calibration is faster, so
use it on coreboor where booting time is important.
Based on patch by Michael Chang.
* grub-core/commands/efi/efifwsetup.c: New file.
* grub-core/kern/efi/efi.c (grub_efi_set_variable): New function
* include/grub/efi/api.h (GRUB_EFI_OS_INDICATIONS_BOOT_TO_FW_UI):
New define.
* include/grub/efi/efi.h (grub_efi_set_variable): New proto.
* grub-core/Makefile.core.def (lsefimmap): New module.
* include/grub/efi/api.h (PRIxGRUB_EFI_UINTN_T): New definition.
Also-By: Robert Millan <rmh.grub@aybabtu.com>
Also-By: Vladimir Serbinenko <phcoder@gmail.com>
* grub-core/Makefile.core.def (lsefimmap): New module.
* include/grub/efi/api.h (PRIxGRUB_EFI_UINTN_T): New definition.
Also-By: Robert Millan <rmh.grub@aybabtu.com>
Also-By: Vladimir Serbinenko <phcoder@gmail.com>
