Currently, the initrd= command line option to the EFI stub only supports
loading files that reside on the same volume as the loaded image, which
is not workable for loaders like GRUB that don't even implement the
volume abstraction (EFI_SIMPLE_FILE_SYSTEM_PROTOCOL), and load the
kernel from an anonymous buffer in memory. For this reason, another
method was devised that relies on the LoadFile2 protocol.
However, the command line loader is rather useful when using the UEFI
shell or other generic loaders that have no awareness of Linux specific
protocols so let's make it a bit more flexible, by permitting textual
device paths to be provided to initrd= as well, provided that they refer
to a file hosted on a EFI_SIMPLE_FILE_SYSTEM_PROTOCOL volume. E.g.,
initrd=PciRoot(0x0)/Pci(0x3,0x0)/HD(1,MBR,0xBE1AFDFA,0x3F,0xFBFC1)/rootfs.cpio.gz
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ampere Altra machines are reported to misbehave when the SetTime() EFI
runtime service is called after ExitBootServices() but before calling
SetVirtualAddressMap(). Given that the latter is horrid, pointless and
explicitly documented as optional by the EFI spec, we no longer invoke
it at boot if the configured size of the VA space guarantees that the
EFI runtime memory regions can remain mapped 1:1 like they are at boot
time.
On Ampere Altra machines, this results in SetTime() calls issued by the
rtc-efi driver triggering synchronous exceptions during boot. We can
now recover from those without bringing down the system entirely, due to
commit 23715a26c8 ("arm64: efi: Recover from synchronous
exceptions occurring in firmware"). However, it would be better to avoid
the issue entirely, given that the firmware appears to remain in a funny
state after this.
So attempt to identify these machines based on the 'family' field in the
type #1 SMBIOS record, and call SetVirtualAddressMap() unconditionally
in that case.
Tested-by: Alexandru Elisei <alexandru.elisei@gmail.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Even though our EFI zboot decompressor is pedantically spec compliant
and idiomatic for EFI image loaders, calling LoadImage() and
StartImage() for the nested image is a bit of a burden. Not only does it
create workflow issues for the distros (as both the inner and outer
PE/COFF images need to be signed for secure boot), it also copies the
image around in memory numerous times:
- first, the image is decompressed into a buffer;
- the buffer is consumed by LoadImage(), which copies the sections into
a newly allocated memory region to hold the executable image;
- once the EFI stub is invoked by StartImage(), it will also move the
image in memory in case of KASLR, mirrored memory or if the image must
execute from a certain a priori defined address.
There are only two EFI spec compliant ways to load code into memory and
execute it:
- use LoadImage() and StartImage(),
- call ExitBootServices() and take ownership of the entire system, after
which anything goes.
Given that the EFI zboot decompressor always invokes the EFI stub, and
given that both are built from the same set of objects, let's merge the
two, so that we can avoid LoadImage()/StartImage but still load our
image into memory without breaking the above rules.
This also means we can decompress the image directly into its final
location, which could be randomized or meet other platform specific
constraints that LoadImage() does not know how to adhere to. It also
means that, even if the encapsulated image still has the EFI stub
incorporated as well, it does not need to be signed for secure boot when
wrapping it in the EFI zboot decompressor.
In the future, we might decide to retire the EFI stub attached to the
decompressed image, but for the time being, they can happily coexist.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Currently, arm64, RISC-V and LoongArch rely on the fact that struct
screen_info can be accessed directly, due to the fact that the EFI stub
and the core kernel are part of the same image. This will change after a
future patch, so let's ensure that the screen_info handling is able to
deal with this, by adopting the arm32 approach of passing it as a
configuration table. While at it, switch to ACPI reclaim memory to hold
the screen_info data, which is more appropriate for this kind of
allocation.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
We no longer need at least 64 bytes of random seed to permit the early
crng init to complete. The RNG is now based on Blake2s, so reduce the
EFI seed size to the Blake2s hash size, which is sufficient for our
purposes.
While at it, drop the READ_ONCE(), which was supposed to prevent size
from being evaluated after seed was unmapped. However, this cannot
actually happen, so READ_ONCE() is unnecessary here.
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Commit bbc6d2c6ef ("efi: vars: Switch to new wrapper layer")
refactored the efivars layer so that the 'business logic' related to
which UEFI variables affect the boot flow in which way could be moved
out of it, and into the efivarfs driver.
This inadvertently broke setting variables on firmware implementations
that lack the QueryVariableInfo() boot service, because we no longer
tolerate a EFI_UNSUPPORTED result from check_var_size() when calling
efivar_entry_set_get_size(), which now ends up calling check_var_size()
a second time inadvertently.
If QueryVariableInfo() is missing, we support writes of up to 64k -
let's move that logic into check_var_size(), and drop the redundant
call.
Cc: <stable@vger.kernel.org> # v6.0
Fixes: bbc6d2c6ef ("efi: vars: Switch to new wrapper layer")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
LoadImage() is supposed to install an instance of the protocol
EFI_LOADED_IMAGE_DEVICE_PATH_PROTOCOL onto the loaded image's handle so
that the program can figure out where it was loaded from. The reference
implementation even does this (with a NULL protocol pointer) if the call
to LoadImage() used the source buffer and size arguments, and passed
NULL for the image device path. Hand rolled implementations of LoadImage
may behave differently, though, and so it is better to tolerate
situations where the protocol is missing. And actually, concatenating an
Offset() node to a NULL device path (as we do currently) is not great
either.
So in cases where the protocol is absent, or when it points to NULL,
construct a MemoryMapped() device node as the base node that describes
the parent image's footprint in memory.
Cc: Daan De Meyer <daandemeyer@fb.com>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
This is necessary because the EFI libstub refactoring patches are mostly
directed at enabling LoongArch to wire up generic EFI boot support
without being forced to consume DT properties that conflict with
information that EFI also provides, e.g., memory map and reservations,
etc.
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Merge tag 'efi-loongarch-for-v6.1-2' into HEAD
Second shared stable tag between EFI and LoongArch trees
This is necessary because the EFI libstub refactoring patches are mostly
directed at enabling LoongArch to wire up generic EFI boot support
without being forced to consume DT properties that conflict with
information that EFI also provides, e.g., memory map and reservations,
etc.
Expose the EFI boot time memory map to the kernel via a configuration
table. This is arch agnostic and enables future changes that remove the
dependency on DT on architectures that don't otherwise rely on it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Use a EFI configuration table to pass the initrd to the core kernel,
instead of per-arch methods. This cleans up the code considerably, and
should make it easier for architectures to get rid of their reliance on
DT for doing EFI boot in the future.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Currently, struct efi_boot_memmap is a struct that is passed around
between callers of efi_get_memory_map() and the users of the resulting
data, and which carries pointers to various variables whose values are
provided by the EFI GetMemoryMap() boot service.
This is overly complex, and it is much easier to carry these values in
the struct itself. So turn the struct into one that carries these data
items directly, including a flex array for the variable number of EFI
memory descriptors that the boot service may return.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Implement a minimal EFI app that decompresses the real kernel image and
launches it using the firmware's LoadImage and StartImage boot services.
This removes the need for any arch-specific hacks.
Note that on systems that have UEFI secure boot policies enabled,
LoadImage/StartImage require images to be signed, or their hashes known
a priori, in order to be permitted to boot.
There are various possible strategies to work around this requirement,
but they all rely either on overriding internal PI/DXE protocols (which
are not part of the EFI spec) or omitting the firmware provided
LoadImage() and StartImage() boot services, which is also undesirable,
given that they encapsulate platform specific policies related to secure
boot and measured boot, but also related to memory permissions (whether
or not and which types of heap allocations have both write and execute
permissions.)
The only generic and truly portable way around this is to simply sign
both the inner and the outer image with the same key/cert pair, so this
is what is implemented here.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Define the correct prototypes for the load_image, start_image and
unload_image boot service pointers so we can call them from the EFI
zboot code.
Also add some prototypes related to installation and deinstallation of
protocols in to the EFI protocol database, including some definitions
related to device paths.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Remove the obsolete 'efivars' sysfs based interface to the EFI variable
store, now that all users have moved to the efivarfs pseudo file system,
which was created ~10 years ago to address some fundamental shortcomings
in the sysfs based driver.
Move the 'business logic' related to which EFI variables are important
and may affect the boot flow from the efivars support layer into the
efivarfs pseudo file system, so it is no longer exposed to other parts
of the kernel.
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Merge tag 'efi-efivars-removal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull efivars sysfs interface removal from Ard Biesheuvel:
"Remove the obsolete 'efivars' sysfs based interface to the EFI
variable store, now that all users have moved to the efivarfs pseudo
file system, which was created ~10 years ago to address some
fundamental shortcomings in the sysfs based driver.
Move the 'business logic' related to which EFI variables are important
and may affect the boot flow from the efivars support layer into the
efivarfs pseudo file system, so it is no longer exposed to other parts
of the kernel"
* tag 'efi-efivars-removal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efi: vars: Move efivar caching layer into efivarfs
efi: vars: Switch to new wrapper layer
efi: vars: Remove deprecated 'efivars' sysfs interface
Currently, the arch_efi_call_virt() assumes all users of it will have
defined a type 'efi_##f##_t' to make use of it.
Simplify the arch_efi_call_virt() macro by eliminating the explicit
need for efi_##f##_t type for every user of this macro.
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
[ardb: apply Sudeep's ARM fix to i686, Loongarch and RISC-V too]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Move the fiddly bits of the efivar layer into its only remaining user,
efivarfs, and confine its use to that particular module. All other uses
of the EFI variable store have no need for this additional layer of
complexity, given that they either only read variables, or read and
write variables into a separate GUIDed namespace, and cannot be used to
manipulate EFI variables that are covered by the EFI spec and/or affect
the boot flow.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
__efivar_entry_iter() uses a list iterator in a dubious way, i.e., it
assumes that the iteration variable always points to an object of the
appropriate type, even if the list traversal exhausts the list
completely, in which case it will point somewhere in the vicinity of the
list's anchor instead.
Fortunately, we no longer use this function so we can just get rid of it
entirely.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Both efivars and efivarfs uses __efivar_entry_iter() to go over the
linked list that shadows the list of EFI variables held by the firmware,
but fail to call the begin/end helpers that are documented as a
prerequisite.
So switch to the proper version, which is efivar_entry_iter(). Given
that in both cases, efivar_entry_remove() is invoked with the lock held
already, don't take the lock there anymore.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Commit 5d9db88376 ("efi: Add support for a UEFI variable filesystem")
dated Oct 5, 2012, introduced a new efivarfs pseudo-filesystem to
replace the efivars sysfs interface that was used up to that point to
expose EFI variables to user space.
The main problem with the sysfs interface was that it only supported up
to 1024 bytes of payload per file, whereas the underlying variables
themselves are only bounded by a platform specific per-variable and
global limit that is typically much higher than 1024 bytes.
The deprecated sysfs interface is only enabled on x86 and Itanium, other
EFI enabled architectures only support the efivarfs pseudo-filesystem.
So let's finally rip off the band aid, and drop the old interface
entirely. This will make it easier to refactor and clean up the
underlying infrastructure that is shared between efivars, efivarfs and
efi-pstore, and is long overdue for a makeover.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Avoid the efivars layer and simply call the newly introduced EFI
varstore helpers instead. This simplifies the code substantially, and
also allows us to remove some hacks in the shared efivars layer that
were added for efi-pstore specifically.
In order to be able to delete the EFI variable associated with a record,
store the UTF-16 name of the variable in the pstore record's priv field.
That way, we don't have to make guesses regarding which variable the
record may have been loaded from.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The current efivars layer is a jumble of list iterators, shadow data
structures and safe variable manipulation helpers that really belong in
the efivarfs pseudo file system once the obsolete sysfs access method to
EFI variables is removed.
So split off a minimal efivar get/set variable API that reuses the
existing efivars_lock semaphore to mediate access to the various runtime
services, primarily to ensure that performing a SetVariable() on one CPU
while another is calling GetNextVariable() in a loop to enumerate the
contents of the EFI variable store does not result in surprises.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Even though the efivars_lock lock is documented as protecting the
efivars->ops pointer (among other things), efivar_init() happily
releases and reacquires the lock for every EFI variable that it
enumerates. This used to be needed because the lock was originally a
spinlock, which prevented the callback that is invoked for every
variable from being able to sleep. However, releasing the lock could
potentially invalidate the ops pointer, but more importantly, it might
allow a SetVariable() runtime service call to take place concurrently,
and the UEFI spec does not define how this affects an enumeration that
is running in parallel using the GetNextVariable() runtime service,
which is what efivar_init() uses.
In the meantime, the lock has been converted into a semaphore, and the
only reason we need to drop the lock is because the efivarfs pseudo
filesystem driver will otherwise deadlock when it invokes the efivars
API from the callback to create the efivar_entry items and insert them
into the linked list. (EFI pstore is affected in a similar way)
So let's switch to helpers that can be used while the lock is already
taken. This way, we can hold on to the lock throughout the enumeration.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Commit b05b9f5f9d ("x86, mirror: x86 enabling - find mirrored memory
ranges") introduce the efi_find_mirror() function on x86. In order to reuse
the API we make it public.
Arm64 can support mirrored memory too, so function efi_find_mirror() is added to
efi_init() to this support for arm64.
Since efi_init() is shared by ARM, arm64 and riscv, this patch will bring
mirror memory support for these architectures, but this support is only tested
in arm64.
Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Link: https://lore.kernel.org/r/20220614092156.1972846-2-mawupeng1@huawei.com
[ardb: fix subject to better reflect the payload]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Add to confidential guests the necessary memory integrity protection
against malicious hypervisor-based attacks like data replay, memory
remapping and others, thus achieving a stronger isolation from the
hypervisor.
At the core of the functionality is a new structure called a reverse
map table (RMP) with which the guest has a say in which pages get
assigned to it and gets notified when a page which it owns, gets
accessed/modified under the covers so that the guest can take an
appropriate action.
In addition, add support for the whole machinery needed to launch a SNP
guest, details of which is properly explained in each patch.
And last but not least, the series refactors and improves parts of the
previous SEV support so that the new code is accomodated properly and
not just bolted on.
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Merge tag 'x86_sev_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull AMD SEV-SNP support from Borislav Petkov:
"The third AMD confidential computing feature called Secure Nested
Paging.
Add to confidential guests the necessary memory integrity protection
against malicious hypervisor-based attacks like data replay, memory
remapping and others, thus achieving a stronger isolation from the
hypervisor.
At the core of the functionality is a new structure called a reverse
map table (RMP) with which the guest has a say in which pages get
assigned to it and gets notified when a page which it owns, gets
accessed/modified under the covers so that the guest can take an
appropriate action.
In addition, add support for the whole machinery needed to launch a
SNP guest, details of which is properly explained in each patch.
And last but not least, the series refactors and improves parts of the
previous SEV support so that the new code is accomodated properly and
not just bolted on"
* tag 'x86_sev_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
x86/entry: Fixup objtool/ibt validation
x86/sev: Mark the code returning to user space as syscall gap
x86/sev: Annotate stack change in the #VC handler
x86/sev: Remove duplicated assignment to variable info
x86/sev: Fix address space sparse warning
x86/sev: Get the AP jump table address from secrets page
x86/sev: Add missing __init annotations to SEV init routines
virt: sevguest: Rename the sevguest dir and files to sev-guest
virt: sevguest: Change driver name to reflect generic SEV support
x86/boot: Put globals that are accessed early into the .data section
x86/boot: Add an efi.h header for the decompressor
virt: sevguest: Fix bool function returning negative value
virt: sevguest: Fix return value check in alloc_shared_pages()
x86/sev-es: Replace open-coded hlt-loop with sev_es_terminate()
virt: sevguest: Add documentation for SEV-SNP CPUID Enforcement
virt: sevguest: Add support to get extended report
virt: sevguest: Add support to derive key
virt: Add SEV-SNP guest driver
x86/sev: Register SEV-SNP guest request platform device
x86/sev: Provide support for SNP guest request NAEs
...
Add support for getting the boot hart ID from the Linux EFI stub using
RISCV_EFI_BOOT_PROTOCOL. This method is preferred over the existing DT
based approach since it works irrespective of DT or ACPI.
The specification of the protocol is hosted at:
https://github.com/riscv-non-isa/riscv-uefi
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Link: https://lore.kernel.org/r/20220519051512.136724-2-sunilvl@ventanamicro.com
[ardb: minor tweaks for coding style and whitespace]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
If the loader has already placed the EFI kernel image randomly in
physical memory, and indicates having done so by installing the 'fixed
placement' protocol onto the image handle, don't bother randomizing the
placement again in the EFI stub.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
UEFI DXE services are not yet used in kernel code
but are required to manipulate page table memory
protection flags.
Add required declarations to use DXE services functions.
Signed-off-by: Baskov Evgeniy <baskov@ispras.ru>
Link: https://lore.kernel.org/r/20220303142120.1975-2-baskov@ispras.ru
[ardb: ignore absent DXE table but warn if the signature check fails]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Confidential computing (coco) hardware such as AMD SEV (Secure Encrypted
Virtualization) allows a guest owner to inject secrets into the VMs
memory without the host/hypervisor being able to read them.
Firmware support for secret injection is available in OVMF, which
reserves a memory area for secret injection and includes a pointer to it
the in EFI config table entry LINUX_EFI_COCO_SECRET_TABLE_GUID.
If EFI exposes such a table entry, uefi_init() will keep a pointer to
the EFI config table entry in efi.coco_secret, so it can be used later
by the kernel (specifically drivers/virt/coco/efi_secret). It will also
appear in the kernel log as "CocoSecret=ADDRESS"; for example:
[ 0.000000] efi: EFI v2.70 by EDK II
[ 0.000000] efi: CocoSecret=0x7f22e680 SMBIOS=0x7f541000 ACPI=0x7f77e000 ACPI 2.0=0x7f77e014 MEMATTR=0x7ea0c018
The new functionality can be enabled with CONFIG_EFI_COCO_SECRET=y.
Signed-off-by: Dov Murik <dovmurik@linux.ibm.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://lore.kernel.org/r/20220412212127.154182-2-dovmurik@linux.ibm.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
While launching encrypted guests, the hypervisor may need to provide
some additional information during the guest boot. When booting under an
EFI-based BIOS, the EFI configuration table contains an entry for the
confidential computing blob that contains the required information.
To support booting encrypted guests on non-EFI VMs, the hypervisor
needs to pass this additional information to the guest kernel using a
different method.
For this purpose, introduce SETUP_CC_BLOB type in setup_data to hold
the physical address of the confidential computing blob location. The
boot loader or hypervisor may choose to use this method instead of an
EFI configuration table. The CC blob location scanning should give
preference to a setup_data blob over an EFI configuration table.
In AMD SEV-SNP, the CC blob contains the address of the secrets and
CPUID pages. The secrets page includes information such as a VM to PSP
communication key and the CPUID page contains PSP-filtered CPUID values.
Define the AMD SEV confidential computing blob structure.
While at it, define the EFI GUID for the confidential computing blob.
[ bp: Massage commit message, mark struct __packed. ]
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220307213356.2797205-30-brijesh.singh@amd.com
- Add support for the the Platform Firmware Runtime Update and
Telemetry (PFRUT) interface based on ACPI to allow certain pieces
of the platform firmware to be updated without restarting the
system and to provide a mechanism for collecting platform firmware
telemetry data (Chen Yu, Dan Carpenter, Yang Yingliang).
- Ignore E820 reservations covering PCI host bridge windows on
sufficiently recent x86 systems to avoid issues with allocating
PCI BARs on systems where the E820 reservations cover the entire
PCI host bridge memory window returned by the _CRS object in the
system's ACPI tables (Hans de Goede).
- Fix and clean up acpi_scan_init() (Rafael Wysocki).
- Add more sanity checking to ACPI SPCR tables parsing (Mark
Langsdorf).
- Fix up ACPI APD (AMD Soc) driver initialization (Jiasheng Jiang).
- Drop unnecessary "static" from the ACPI PCC address space handling
driver added recently (kernel test robot).
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Merge tag 'acpi-5.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more ACPI updates from Rafael Wysocki:
"The most significant item here is the Platform Firmware Runtime Update
and Telemetry (PFRUT) support designed to allow certain pieces of the
platform firmware to be updated on the fly, among other things.
Also important is the e820 handling change on x86 that should work
around PCI BAR allocation issues on some systems shipping since 2019.
The rest is just a handful of assorted fixes and cleanups on top of
the ACPI material merged previously.
Specifics:
- Add support for the the Platform Firmware Runtime Update and
Telemetry (PFRUT) interface based on ACPI to allow certain pieces
of the platform firmware to be updated without restarting the
system and to provide a mechanism for collecting platform firmware
telemetry data (Chen Yu, Dan Carpenter, Yang Yingliang).
- Ignore E820 reservations covering PCI host bridge windows on
sufficiently recent x86 systems to avoid issues with allocating PCI
BARs on systems where the E820 reservations cover the entire PCI
host bridge memory window returned by the _CRS object in the
system's ACPI tables (Hans de Goede).
- Fix and clean up acpi_scan_init() (Rafael Wysocki).
- Add more sanity checking to ACPI SPCR tables parsing (Mark
Langsdorf).
- Fix up ACPI APD (AMD Soc) driver initialization (Jiasheng Jiang).
- Drop unnecessary "static" from the ACPI PCC address space handling
driver added recently (kernel test robot)"
* tag 'acpi-5.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI: PCC: pcc_ctx can be static
ACPI: scan: Rename label in acpi_scan_init()
ACPI: scan: Simplify initialization of power and sleep buttons
ACPI: scan: Change acpi_scan_init() return value type to void
ACPI: SPCR: check if table->serial_port.access_width is too wide
ACPI: APD: Check for NULL pointer after calling devm_ioremap()
x86/PCI: Ignore E820 reservations for bridge windows on newer systems
ACPI: pfr_telemetry: Fix info leak in pfrt_log_ioctl()
ACPI: pfr_update: Fix return value check in pfru_write()
ACPI: tools: Introduce utility for firmware updates/telemetry
ACPI: Introduce Platform Firmware Runtime Telemetry driver
ACPI: Introduce Platform Firmware Runtime Update device driver
efi: Introduce EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER and corresponding structures
Merge support for the Platform Firmware Runtime Update and Telemetry
interface based on ACPI.
The interface provided here allows updating certain pieces of the
platform firmware without restarting the system and collecting
platform firmware telemetry data.
This also includes a utility for accesing the new interface from user
space.
* acpi-pfrut:
ACPI: pfr_telemetry: Fix info leak in pfrt_log_ioctl()
ACPI: pfr_update: Fix return value check in pfru_write()
ACPI: tools: Introduce utility for firmware updates/telemetry
ACPI: Introduce Platform Firmware Runtime Telemetry driver
ACPI: Introduce Platform Firmware Runtime Update device driver
efi: Introduce EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER and corresponding structures
- support taking the measurement of the initrd when loaded via the
LoadFile2 protocol
- kobject API cleanup from Greg
- some header file whitespace fixes
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Merge tag 'efi-next-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull EFI updates from Ard Biesheuvel:
- support taking the measurement of the initrd when loaded via the
LoadFile2 protocol
- kobject API cleanup from Greg
- some header file whitespace fixes
* tag 'efi-next-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efi: use default_groups in kobj_type
efi/libstub: measure loaded initrd info into the TPM
efi/libstub: consolidate initrd handling across architectures
efi/libstub: x86/mixed: increase supported argument count
efi/libstub: add prototype of efi_tcg2_protocol::hash_log_extend_event()
include/linux/efi.h: Remove unneeded whitespaces before tabs
Platform Firmware Runtime Update image starts with UEFI headers, and the
headers are defined in UEFI specification, but some of them have not been
defined in the kernel yet.
For example, the header layout of a capsule file looks like this:
EFI_CAPSULE_HEADER
EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER
EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER
EFI_FIRMWARE_IMAGE_AUTHENTICATION
These structures would be used by the Platform Firmware Runtime Update
driver to parse the format of capsule file to verify if the corresponding
version number is valid. In this way, if the user provides an invalid
capsule image, the kernel could be used as a guard to reject it, without
switching to the Management Mode (which might be costly).
EFI_CAPSULE_HEADER has been defined in the kernel, but the other
structures have not been defined yet, so do that. Besides,
EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER and
EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER are required to be packed
in the uefi specification. For this reason, use the __packed attribute
to indicate to the compiler that the entire structure can appear
misaligned in memory (as suggested by Ard) in case one of them follows
the other directly in a capsule header.
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit 8633ef82f1 ("drivers/firmware: consolidate EFI framebuffer setup
for all arches") made the Generic System Framebuffers (sysfb) driver able
to be built on non-x86 architectures.
But it left the efifb_setup_from_dmi() function prototype declaration in
the architecture specific headers. This could lead to the following
compiler warning as reported by the kernel test robot:
drivers/firmware/efi/sysfb_efi.c:70:6: warning: no previous prototype for function 'efifb_setup_from_dmi' [-Wmissing-prototypes]
void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
^
drivers/firmware/efi/sysfb_efi.c:70:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
Fixes: 8633ef82f1 ("drivers/firmware: consolidate EFI framebuffer setup for all arches")
Reported-by: kernel test robot <lkp@intel.com>
Cc: <stable@vger.kernel.org> # 5.15.x
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20211126001333.555514-1-javierm@redhat.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Introduce a new AMD Memory Encryption GUID which is currently
used for defining a new UEFI environment variable which indicates
UEFI/OVMF support for the SEV live migration feature. This variable
is setup when UEFI/OVMF detects host/hypervisor support for SEV
live migration and later this variable is read by the kernel using
EFI runtime services to verify if OVMF supports the live migration
feature.
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Message-Id: <1cea22976d2208f34d47e0c1ce0ecac816c13111.1629726117.git.ashish.kalra@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit 494c704f9a ("efi: Use 32-bit alignment for efi_guid_t") updated
the type definition of efi_guid_t to ensure that it always appears
sufficiently aligned (the UEFI spec is ambiguous about this, but given
the fact that its EFI_GUID type is defined in terms of a struct carrying
a uint32_t, the natural alignment is definitely >= 32 bits).
However, we missed the EFI_GUID() macro which is used to instantiate
efi_guid_t literals: that macro is still based on the guid_t type,
which does not have a minimum alignment at all. This results in warnings
such as
In file included from drivers/firmware/efi/mokvar-table.c:35:
include/linux/efi.h:1093:34: warning: passing 1-byte aligned argument to
4-byte aligned parameter 2 of 'get_var' may result in an unaligned pointer
access [-Walign-mismatch]
status = get_var(L"SecureBoot", &EFI_GLOBAL_VARIABLE_GUID, NULL, &size,
^
include/linux/efi.h:1101:24: warning: passing 1-byte aligned argument to
4-byte aligned parameter 2 of 'get_var' may result in an unaligned pointer
access [-Walign-mismatch]
get_var(L"SetupMode", &EFI_GLOBAL_VARIABLE_GUID, NULL, &size, &setupmode);
The distinction only matters on CPUs that do not support misaligned loads
fully, but 32-bit ARM's load-multiple instructions fall into that category,
and these are likely to be emitted by the compiler that built the firmware
for loading word-aligned 128-bit GUIDs from memory
So re-implement the initializer in terms of our own efi_guid_t type, so that
the alignment becomes a property of the literal's type.
Fixes: 494c704f9a ("efi: Use 32-bit alignment for efi_guid_t")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/1327
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Move TPM related definitions that are only used in the EFI stub into
efistub.h, which is a local header.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Move some EFI related declarations that are only referenced on IA64 to
a new asm/efi.h arch header.
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
EFI capsule loading is a feature that was introduced into EFI long after
its initial introduction on Itanium, and it is highly unlikely that IA64
systems are receiving firmware updates in the first place, let alone
using EFI capsules.
So let's disable capsule support altogether on IA64. This fixes a build
error on IA64 due to a recent change that added an unconditional
include of asm/efi.h, which IA64 does not provide.
While at it, tweak the make rules a bit so that the EFI capsule
component that is always builtin (even if the EFI capsule loader itself
is built as a module) is omitted for all architectures if the module is
not enabled in the build.
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/linux-efi/20201214152200.38353-1-ardb@kernel.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Generalize the efi_get_secureboot() function so not only efistub but also
other subsystems can use it.
Note that the MokSbState handling is not factored out: the variable is
boot time only, and so it cannot be parameterized as easily. Also, the
IMA code will switch to this version in a future patch, and it does not
incorporate the MokSbState exception in the first place.
Note that the new efi_get_secureboot_mode() helper treats any failures
to read SetupMode as setup mode being disabled.
Co-developed-by: Chester Lin <clin@suse.com>
Signed-off-by: Chester Lin <clin@suse.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
efivars_sysfs_init() is only used locally in the source file that
defines it, so make it static and unexport it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The worker thread that gets kicked off to sync the state of the
EFI variable list is only used by the EFI pstore implementation,
and is defined in its source file. So let's move its scheduling
there as well. Since our efivar_init() scan will bail on duplicate
entries, there is no need to disable the workqueue like we did
before, so we can run it unconditionally.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The EFI pstore implementation relies on the 'efivars' abstraction,
which encapsulates the EFI variable store in a way that can be
overridden by other backing stores, like the Google SMI one.
On top of that, the EFI pstore implementation also relies on the
efivars.ko module, which is a separate layer built on top of the
'efivars' abstraction that exposes the [deprecated] sysfs entries
for each variable that exists in the backing store.
Since the efivars.ko module is deprecated, and all users appear to
have moved to the efivarfs file system instead, let's prepare for
its removal, by removing EFI pstore's dependency on it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Incorporate the definition of EFI_MEMORY_CPU_CRYPTO from the UEFI
specification v2.8, and wire it into our memory map dumping routine
as well.
To make a bit of space in the output buffer, which is provided by
the various callers, shorten the descriptive names of the memory
types.
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Because of system-specific EFI firmware limitations, EFI volatile
variables may not be capable of holding the required contents of
the Machine Owner Key (MOK) certificate store when the certificate
list grows above some size. Therefore, an EFI boot loader may pass
the MOK certs via a EFI configuration table created specifically for
this purpose to avoid this firmware limitation.
An EFI configuration table is a much more primitive mechanism
compared to EFI variables and is well suited for one-way passage
of static information from a pre-OS environment to the kernel.
This patch adds initial kernel support to recognize, parse,
and validate the EFI MOK configuration table, where named
entries contain the same data that would otherwise be provided
in similarly named EFI variables.
Additionally, this patch creates a sysfs binary file for each
EFI MOK configuration table entry found. These files are read-only
to root and are provided for use by user space utilities such as
mokutil.
A subsequent patch will load MOK certs into the trusted platform
key ring using this infrastructure.
Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com>
Link: https://lore.kernel.org/r/20200905013107.10457-2-lszubowi@redhat.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
When CONFIG_EFI is not enabled, we might get an undefined reference to
efi_enter_virtual_mode() error, if this efi_enabled() call isn't inlined
into start_kernel(). This happens in particular, if start_kernel() is
annodated with __no_sanitize_address.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Elena Petrova <lenaptr@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Walter Wu <walter-zh.wu@mediatek.com>
Link: http://lkml.kernel.org/r/6514652d3a32d3ed33d6eb5c91d0af63bf0d1a0c.1596544734.git.andreyknvl@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit
bf67fad19e ("efi: Use more granular check for availability for variable services")
introduced a check into the efivarfs, efi-pstore and other drivers that
aborts loading of the module if not all three variable runtime services
(GetVariable, SetVariable and GetNextVariable) are supported. However, this
results in efivarfs being unavailable entirely if only SetVariable support
is missing, which is only needed if you want to make any modifications.
Also, efi-pstore and the sysfs EFI variable interface could be backed by
another implementation of the 'efivars' abstraction, in which case it is
completely irrelevant which services are supported by the EFI firmware.
So make the generic 'efivars' abstraction dependent on the availibility of
the GetVariable and GetNextVariable EFI runtime services, and add a helper
'efivar_supports_writes()' to find out whether the currently active efivars
abstraction supports writes (and wire it up to the availability of
SetVariable for the generic one).
Then, use the efivar_supports_writes() helper to decide whether to permit
efivarfs to be mounted read-write, and whether to enable efi-pstore or the
sysfs EFI variable interface altogether.
Fixes: bf67fad19e ("efi: Use more granular check for availability for variable services")
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
On 32-bit ARM, we may boot at HYP mode, or with the MMU and caches off
(or both), even though the EFI spec does not actually support this.
While booting at HYP mode is something we might tolerate, fiddling
with the caches is a more serious issue, as disabling the caches is
tricky to do safely from C code, and running without the Dcache makes
it impossible to support unaligned memory accesses, which is another
explicit requirement imposed by the EFI spec.
So take note of the CPU mode and MMU state in the EFI stub diagnostic
output so that we can easily diagnose any issues that may arise from
this. E.g.,
EFI stub: Entering in SVC mode with MMU enabled
Also, capture the CPSR and SCTLR system register values at EFI stub
entry, and after ExitBootServices() returns, and check whether the
MMU and Dcache were disabled at any point. If this is the case, a
diagnostic message like the following will be emitted:
efi: [Firmware Bug]: EFI stub was entered with MMU and Dcache disabled, please fix your firmware!
efi: CPSR at EFI stub entry : 0x600001d3
efi: SCTLR at EFI stub entry : 0x00c51838
efi: CPSR after ExitBootServices() : 0x600001d3
efi: SCTLR after ExitBootServices(): 0x00c50838
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Leif Lindholm <leif@nuviainc.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
Lastly, make use of the sizeof_field() helper instead of an open-coded
version.
This issue was found with the help of Coccinelle and audited _manually_.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200527171425.GA4053@embeddedor
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
- Rename pr_efi/pr_efi_err to efi_info/efi_err, and use them consistently
- Simplify and unify initrd loading
- Parse the builtin command line on x86 (if provided)
- Implement printk() support, including support for wide character strings
- Some fixes for issues introduced by the first batch of v5.8 changes
- Fix a missing prototypes warning
- Simplify GDT handling in early mixed mode thunking code
- Some other minor fixes and cleanups
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Merge tag 'efi-changes-for-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core
More EFI changes for v5.8:
- Rename pr_efi/pr_efi_err to efi_info/efi_err, and use them consistently
- Simplify and unify initrd loading
- Parse the builtin command line on x86 (if provided)
- Implement printk() support, including support for wide character strings
- Some fixes for issues introduced by the first batch of v5.8 changes
- Fix a missing prototypes warning
- Simplify GDT handling in early mixed mode thunking code
- Some other minor fixes and cleanups
Conflicts:
drivers/firmware/efi/libstub/efistub.h
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add the required typedefs etc for using con_in's simple text input
protocol, and for using the boottime event services.
Also add the prototype for the "stall" boot service.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-19-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Pull up arch-specific prototype efi_systab_show_arch() in order to
fix a -Wmissing-prototypes warning:
arch/x86/platform/efi/efi.c:957:7: warning: no previous prototype for
‘efi_systab_show_arch’ [-Wmissing-prototypes]
char *efi_systab_show_arch(char *str)
Signed-off-by: Benjamin Thiel <b.thiel@posteo.de>
Link: https://lore.kernel.org/r/20200516132647.14568-1-b.thiel@posteo.de
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Increase legibility by adding whitespace to the efi_config_table_type_t
arrays that describe which EFI config tables we look for when going over
the firmware provided list. While at it, replace the 'name' char pointer
with a char array, which is more space efficient on relocatable 64-bit
kernels, as it avoids a 8 byte pointer and the associated relocation
data (24 bytes when using RELA format)
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Pull x86 cleanups from Ingo Molnar:
"This topic tree contains more commits than usual:
- most of it are uaccess cleanups/reorganization by Al
- there's a bunch of prototype declaration (--Wmissing-prototypes)
cleanups
- misc other cleanups all around the map"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
x86/mm/set_memory: Fix -Wmissing-prototypes warnings
x86/efi: Add a prototype for efi_arch_mem_reserve()
x86/mm: Mark setup_emu2phys_nid() static
x86/jump_label: Move 'inline' keyword placement
x86/platform/uv: Add a missing prototype for uv_bau_message_interrupt()
kill uaccess_try()
x86: unsafe_put-style macro for sigmask
x86: x32_setup_rt_frame(): consolidate uaccess areas
x86: __setup_rt_frame(): consolidate uaccess areas
x86: __setup_frame(): consolidate uaccess areas
x86: setup_sigcontext(): list user_access_{begin,end}() into callers
x86: get rid of put_user_try in __setup_rt_frame() (both 32bit and 64bit)
x86: ia32_setup_rt_frame(): consolidate uaccess areas
x86: ia32_setup_frame(): consolidate uaccess areas
x86: ia32_setup_sigcontext(): lift user_access_{begin,end}() into the callers
x86/alternatives: Mark text_poke_loc_init() static
x86/cpu: Fix a -Wmissing-prototypes warning for init_ia32_feat_ctl()
x86/mm: Drop pud_mknotpresent()
x86: Replace setup_irq() by request_irq()
x86/configs: Slightly reduce defconfigs
...
... in order to fix a -Wmissing-ptototypes warning:
arch/x86/platform/efi/quirks.c:245:13: warning:
no previous prototype for ‘efi_arch_mem_reserve’ [-Wmissing-prototypes] \
void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
Signed-off-by: Benjamin Thiel <b.thiel@posteo.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200326135041.3264-1-b.thiel@posteo.de
More EFI updates for v5.7
- Incorporate a stable branch with the EFI pieces of Hans's work on
loading device firmware from EFI boot service memory regions
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Just like with PCI options ROMs, which we save in the setup_efi_pci*
functions from arch/x86/boot/compressed/eboot.c, the EFI code / ROM itself
sometimes may contain data which is useful/necessary for peripheral drivers
to have access to.
Specifically the EFI code may contain an embedded copy of firmware which
needs to be (re)loaded into the peripheral. Normally such firmware would be
part of linux-firmware, but in some cases this is not feasible, for 2
reasons:
1) The firmware is customized for a specific use-case of the chipset / use
with a specific hardware model, so we cannot have a single firmware file
for the chipset. E.g. touchscreen controller firmwares are compiled
specifically for the hardware model they are used with, as they are
calibrated for a specific model digitizer.
2) Despite repeated attempts we have failed to get permission to
redistribute the firmware. This is especially a problem with customized
firmwares, these get created by the chip vendor for a specific ODM and the
copyright may partially belong with the ODM, so the chip vendor cannot
give a blanket permission to distribute these.
This commit adds support for finding peripheral firmware embedded in the
EFI code and makes the found firmware available through the new
efi_get_embedded_fw() function.
Support for loading these firmwares through the standard firmware loading
mechanism is added in a follow-up commit in this patch-series.
Note we check the EFI_BOOT_SERVICES_CODE for embedded firmware near the end
of start_kernel(), just before calling rest_init(), this is on purpose
because the typical EFI_BOOT_SERVICES_CODE memory-segment is too large for
early_memremap(), so the check must be done after mm_init(). This relies
on EFI_BOOT_SERVICES_CODE not being free-ed until efi_free_boot_services()
is called, which means that this will only work on x86 for now.
Reported-by: Dave Olsthoorn <dave@bewaar.me>
Suggested-by: Peter Jones <pjones@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200115163554.101315-3-hdegoede@redhat.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Sometimes it is useful to be able to dump the efi boot-services code and
data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
but only if efi=debug is passed on the kernel-commandline as this requires
not freeing those memory-regions, which costs 20+ MB of RAM.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200115163554.101315-2-hdegoede@redhat.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Take the newly introduced EFI_RT_PROPERTIES_TABLE configuration table
into account, which carries a mask of which EFI runtime services are
still functional after ExitBootServices() has been called by the OS.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Revision 2.8 of the UEFI spec introduces provisions for firmware to
advertise lack of support for certain runtime services at OS runtime.
Let's store this mask in struct efi for easy access.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Push the FDT params specific types and definition into fdtparams.c,
and instead, pass a reference to the memory map data structure and
populate it directly, and return the system table address as the
return value.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The systab member in struct efi has outlived its usefulness, now that
we have better ways to access the only piece of information we are
interested in after init, which is the EFI runtime services table
address. So instead of instantiating a doctored copy at early boot
with lots of mangled values, and switching the pointer when switching
into virtual mode, let's grab the values we need directly, and get
rid of the systab pointer entirely.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Instead of going through the EFI system table each time, just copy the
runtime services table pointer into struct efi directly. This is the
last use of the system table pointer in struct efi, allowing us to
drop it in a future patch, along with a fair amount of quirky handling
of the translated address.
Note that usually, the runtime services pointer changes value during
the call to SetVirtualAddressMap(), so grab the updated value as soon
as that call returns. (Mixed mode uses a 1:1 mapping, and kexec boot
enters with the updated address in the system table, so in those cases,
we don't need to do anything here)
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
There is some code that exposes physical addresses of certain parts of
the EFI firmware implementation via sysfs nodes. These nodes are only
used on x86, and are of dubious value to begin with, so let's move
their handling into the x86 arch code.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
config_parse_tables() is a jumble of pointer arithmetic, due to the
fact that on x86, we may be dealing with firmware whose native word
size differs from the kernel's.
This is not a concern on other architectures, and doesn't quite
justify the state of the code, so let's clean it up by adding a
non-x86 code path, constifying statically allocated tables and
replacing preprocessor conditionals with IS_ENABLED() checks.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The efi_config_init() routine is no longer shared with ia64 so let's
move it into the x86 arch code before making further x86 specific
changes to it.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
We have three different versions of the code that checks the EFI system
table revision and copies the firmware vendor string, and they are
mostly equivalent, with the exception of the use of early_memremap_ro
vs. __va() and the lowest major revision to warn about. Let's move this
into common code and factor out the commonalities.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
There is no need for struct efi to carry the address of the memreserve
table and share it with the world. So move it out and make it
__initdata as well.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The memory attributes table is only used at init time by the core EFI
code, so there is no need to carry its address in struct efi that is
shared with the world. So move it out, and make it __ro_after_init as
well, considering that the value is set during early boot.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Move the rng_seed table address from struct efi into a static global
variable in efi.c, which is the only place we ever refer to it anyway.
This reduces the footprint of struct efi, which is a r/w data structure
that is shared with the world.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The UGA table is x86 specific (its handling was introduced when the
EFI support code was modified to accommodate IA32), so there is no
need to handle it in generic code.
The EFI properties table is not strictly x86 specific, but it was
deprecated almost immediately after having been introduced, due to
implementation difficulties. Only x86 takes it into account today,
and this is not going to change, so make this table x86 only as well.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The HCDP and MPS tables are Itanium specific EFI config tables, so
move their handling to ia64 arch code.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Some plumbing exists to handle a UEFI configuration table of type
BOOT_INFO but since we never match it to a GUID anywhere, we never
actually register such a table, or access it, for that matter. So
simply drop all mentions of it.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
There are currently two ways to specify the initrd to be passed to the
Linux kernel when booting via the EFI stub:
- it can be passed as a initrd= command line option when doing a pure PE
boot (as opposed to the EFI handover protocol that exists for x86)
- otherwise, the bootloader or firmware can load the initrd into memory,
and pass the address and size via the bootparams struct (x86) or
device tree (ARM)
In the first case, we are limited to loading from the same file system
that the kernel was loaded from, and it is also problematic in a trusted
boot context, given that we cannot easily protect the command line from
tampering without either adding complicated white/blacklisting of boot
arguments or locking down the command line altogether.
In the second case, we force the bootloader to duplicate knowledge about
the boot protocol which is already encoded in the stub, and which may be
subject to change over time, e.g., bootparams struct definitions, memory
allocation/alignment requirements for the placement of the initrd etc etc.
In the ARM case, it also requires the bootloader to modify the hardware
description provided by the firmware, as it is passed in the same file.
On systems where the initrd is measured after loading, it creates a time
window where the initrd contents might be manipulated in memory before
handing over to the kernel.
Address these concerns by adding support for loading the initrd into
memory by invoking the EFI LoadFile2 protocol installed on a vendor
GUIDed device path that specifically designates a Linux initrd.
This addresses the above concerns, by putting the EFI stub in charge of
placement in memory and of passing the base and size to the kernel proper
(via whatever means it desires) while still leaving it up to the firmware
or bootloader to obtain the file contents, potentially from other file
systems than the one the kernel itself was loaded from. On platforms that
implement measured boot, it permits the firmware to take the measurement
right before the kernel actually consumes the contents.
Acked-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
In preparation of adding support for loading the initrd via a special
device path, add the struct definition of a vendor GUIDed device path
node to efi.h.
Since we will be producing these data structures rather than just
consumsing the ones instantiated by the firmware, refactor the various
device path node definitions so we can take the size of each node using
sizeof() rather than having to resort to opaque arithmetic in the static
initializers.
While at it, drop the #if IS_ENABLED() check for the declaration of
efi_get_device_by_path(), which is unnecessary, and constify its first
argument as well.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Add the protocol definitions, GUIDs and mixed mode glue so that
the EFI loadfile protocol can be used from the stub. This will
be used in a future patch to load the initrd.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Move all the declarations that are only used in stub code from
linux/efi.h to efistub.h which is only included locally.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Align the naming of efi_file_io_interface_t and efi_file_handle_t with
the UEFI spec, and call them efi_simple_file_system_protocol_t and
efi_file_protocol_t, respectively, using the same convention we use
for all other type definitions that originate in the UEFI spec.
While at it, move the definitions to efistub.h, so they are only seen
by code that needs them.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The implementation of efi_high_alloc() uses a complicated way of
traversing the memory map to find an available region that is located
as close as possible to the provided upper limit, and calls AllocatePages
subsequently to create the allocation at that exact address.
This is precisely what the EFI_ALLOCATE_MAX_ADDRESS allocation type
argument to AllocatePages() does, and considering that EFI_ALLOC_ALIGN
only exceeds EFI_PAGE_SIZE on arm64, let's use AllocatePages() directly
and implement the alignment using code that the compiler can remove if
it does not exceed EFI_PAGE_SIZE.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Dave noticed that when specifying multiple efi_fake_mem= entries only
the last entry was successfully being reflected in the efi memory map.
This is due to the fact that the efi_memmap_insert() is being called
multiple times, but on successive invocations the insertion should be
applied to the last new memmap rather than the original map at
efi_fake_memmap() entry.
Rework efi_fake_memmap() to install the new memory map after each
efi_fake_mem= entry is parsed.
This also fixes an issue in efi_fake_memmap() that caused it to litter
emtpy entries into the end of the efi memory map. An empty entry causes
efi_memmap_insert() to attempt more memmap splits / copies than
efi_memmap_split_count() accounted for when sizing the new map. When
that happens efi_memmap_insert() may overrun its allocation, and if you
are lucky will spill over to an unmapped page leading to crash
signature like the following rather than silent corruption:
BUG: unable to handle page fault for address: ffffffffff281000
[..]
RIP: 0010:efi_memmap_insert+0x11d/0x191
[..]
Call Trace:
? bgrt_init+0xbe/0xbe
? efi_arch_mem_reserve+0x1cb/0x228
? acpi_parse_bgrt+0xa/0xd
? acpi_table_parse+0x86/0xb8
? acpi_boot_init+0x494/0x4e3
? acpi_parse_x2apic+0x87/0x87
? setup_acpi_sci+0xa2/0xa2
? setup_arch+0x8db/0x9e1
? start_kernel+0x6a/0x547
? secondary_startup_64+0xb6/0xc0
Commit af16489848 "x86/efi: Update e820 with reserved EFI boot
services data to fix kexec breakage" introduced more occurrences where
efi_memmap_insert() is invoked after an efi_fake_mem= configuration has
been parsed. Previously the side effects of vestigial empty entries were
benign, but with commit af16489848 that follow-on efi_memmap_insert()
invocation triggers efi_memmap_insert() overruns.
Reported-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20191231014630.GA24942@dhcp-128-65.nay.redhat.com
Link: https://lore.kernel.org/r/20200113172245.27925-14-ardb@kernel.org
In preparation for fixing efi_memmap_alloc() leaks, add support for
recording whether the memmap was dynamically allocated from slab,
memblock, or is the original physical memmap provided by the platform.
Given this tracking is established in efi_memmap_alloc() and needs to be
carried to efi_memmap_install(), use 'struct efi_memory_map_data' to
convey the flags.
Some small cleanups result from this reorganization, specifically the
removal of local variables for 'phys' and 'size' that are already
tracked in @data.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200113172245.27925-12-ardb@kernel.org
In preparation for garbage collecting dynamically allocated EFI memory
maps, where the allocation method of memblock vs slab needs to be
recalled, convert the existing 'late' flag into a 'flags' bitmask.
Arrange for the flag to be passed via 'struct efi_memory_map_data'. This
structure grows additional flags in follow-on changes.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200113172245.27925-11-ardb@kernel.org
Add an option to disable the busmaster bit in the control register on
all PCI bridges before calling ExitBootServices() and passing control
to the runtime kernel. System firmware may configure the IOMMU to prevent
malicious PCI devices from being able to attack the OS via DMA. However,
since firmware can't guarantee that the OS is IOMMU-aware, it will tear
down IOMMU configuration when ExitBootServices() is called. This leaves
a window between where a hostile device could still cause damage before
Linux configures the IOMMU again.
If CONFIG_EFI_DISABLE_PCI_DMA is enabled or "efi=disable_early_pci_dma"
is passed on the command line, the EFI stub will clear the busmaster bit
on all PCI bridges before ExitBootServices() is called. This will
prevent any malicious PCI devices from being able to perform DMA until
the kernel reenables busmastering after configuring the IOMMU.
This option may cause failures with some poorly behaved hardware and
should not be enabled without testing. The kernel commandline options
"efi=disable_early_pci_dma" or "efi=no_disable_early_pci_dma" may be
used to override the default. Note that PCI devices downstream from PCI
bridges are disconnected from their drivers first, using the UEFI
driver model API, so that DMA can be disabled safely at the bridge
level.
[ardb: disconnect PCI I/O handles first, as suggested by Arvind]
Co-developed-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Matthew Garrett <matthewgarrett@google.com>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20200103113953.9571-18-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The routines efi_runtime_init32() and efi_runtime_init64() are
almost indistinguishable, and the only relevant difference is
the offset in the runtime struct from where to obtain the physical
address of the SetVirtualAddressMap() routine.
However, this address is only used once, when installing the virtual
address map that the OS will use to invoke EFI runtime services, and
at the time of the call, we will necessarily be running with a 1:1
mapping, and so there is no need to do the map/unmap dance here to
retrieve the address. In fact, in the preceding changes to these users,
we stopped using the address recorded here entirely.
So let's just get rid of all this code since it no longer serves a
purpose. While at it, tweak the logic so that we handle unsupported
and disable EFI runtime services in the same way, and unmap the EFI
memory map in both cases.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Matthew Garrett <mjg59@google.com>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20200103113953.9571-12-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
All EFI firmware call prototypes have been annotated as __efiapi,
permitting us to attach attributes regarding the calling convention
by overriding __efiapi to an architecture specific value.
On 32-bit x86, EFI firmware calls use the plain calling convention
where all arguments are passed via the stack, and cleaned up by the
caller. Let's add this to the __efiapi definition so we no longer
need to cast the function pointers before invoking them.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Matthew Garrett <mjg59@google.com>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20200103113953.9571-6-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We have a helper efi_system_table() that gives us the address of the
EFI system table in memory, so there is no longer point in passing
it around from each function to the next.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-20-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As a first step towards getting rid of the need to pass around a function
parameter 'sys_table_arg' pointing to the EFI system table, remove the
references to it in the printing code, which is represents the majority
of the use cases.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-19-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The EFI file I/O routines built on top of the file I/O firmware
services are incompatible with mixed mode, so there is no need
to obfuscate them by using protocol wrappers whose only purpose
is to hide the mixed mode handling. So let's switch to plain
indirect calls instead.
This also means we can drop the mixed_mode aliases from the various
types involved.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-15-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Annotate all the firmware routines (boot services, runtime services and
protocol methods) called in the boot context as __efiapi, and make
it expand to __attribute__((ms_abi)) on 64-bit x86. This allows us
to use the compiler to generate the calls into firmware that use the
MS calling convention instead of the SysV one.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-13-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We will soon remove another level of pointer casting, so let's make
sure all type handling involving firmware calls at boot time is correct.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-12-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Ard Biesheuvel