efi: fix panic in kdump kernel

Check if get_next_variable() is actually valid pointer before
calling it. In kdump kernel this method is set to NULL that causes
panic during the kexec-ed kernel boot.

Tested with QEMU and OVMF firmware.

Fixes: bad267f9e18f ("efi: verify that variable services are supported")
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi/libstub: Add get_event_log() support for CC platforms

To allow event log info access after boot, EFI boot stub extracts
the event log information and installs it in an EFI configuration
table. Currently, EFI boot stub only supports installation of event
log only for TPM 1.2 and TPM 2.0 protocols. Extend the same support
for CC protocol. Since CC platform also uses TCG2 format, reuse TPM2
support code as much as possible.

Link: https://uefi.org/specs/UEFI/2.10/38_Confidential_Computing.html#efi-cc-measurement-protocol [1]
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://lkml.kernel.org/r/0229a87e-fb19-4dad-99fc-4afd7ed4099a%40collabora.com
[ardb: Split out final events table handling to avoid version confusion]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi/tpm: Use symbolic GUID name from spec for final events table

The LINUX_EFI_ GUID identifiers are only intended to be used to refer to
GUIDs that are part of the Linux implementation, and are not considered
external ABI. (Famous last words).

GUIDs that already have a symbolic name in the spec should use that
name, to avoid confusion between firmware components. So use the
official name EFI_TCG2_FINAL_EVENTS_TABLE_GUID for the TCG2 'final
events' configuration table.

Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efivarfs: automatically update super block flag

efivar operation is updated when the tee_stmm_efi module is probed.
tee_stmm_efi module supports SetVariable runtime service, but user needs
to manually remount the efivarfs as RW to enable the write access if the
previous efivar operation does not support SetVariable and efivarfs is
mounted as read-only.

This commit notifies the update of efivar operation to efivarfs
subsystem, then drops SB_RDONLY flag if the efivar operation supports
SetVariable.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
[ardb: use per-superblock instance of the notifier block]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: expose efivar generic ops register function

This is a preparation for supporting efivar operations provided by other
than efi subsystem. Both register and unregister functions are exposed
so that non-efi subsystem can revert the efi generic operation.

Acked-by: Sumit Garg <sumit.garg@linaro.org>
Co-developed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

arch: Remove Itanium (IA-64) architecture

The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS based. The use of Linux on Itanium appears to be limited to
enthusiasts that occasionally boot a fresh Linux kernel to see whether
things are still working as intended, and perhaps to churn out some
distro packages that are rarely used in practice.

None of the original companies behind Itanium still produce or support
any hardware or software for the architecture, and it is listed as
'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers
that contributed on behalf of those companies (nor anyone else, for that
matter) have been willing to support or maintain the architecture
upstream or even be responsible for applying the odd fix. The Intel
firmware team removed all IA-64 support from the Tianocore/EDK2
reference implementation of EFI in 2018. (Itanium is the original
architecture for which EFI was developed, and the way Linux supports it
deviates significantly from other architectures.) Some distros, such as
Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have
dropped support years ago.

While the argument is being made [1] that there is a 'for the common
good' angle to being able to build and run existing projects such as the
Grid Community Toolkit [2] on Itanium for interoperability testing, the
fact remains that none of those projects are known to be deployed on
Linux/ia64, and very few people actually have access to such a system in
the first place. Even if there were ways imaginable in which Linux/ia64
could be put to good use today, what matters is whether anyone is
actually doing that, and this does not appear to be the case.

There are no emulators widely available, and so boot testing Itanium is
generally infeasible for ordinary contributors. GCC still supports IA-64
but its compile farm [3] no longer has any IA-64 machines. GLIBC would
like to get rid of IA-64 [4] too because it would permit some overdue
code cleanups. In summary, the benefits to the ecosystem of having IA-64
be part of it are mostly theoretical, whereas the maintenance overhead
of keeping it supported is real.

So let's rip off the band aid, and remove the IA-64 arch code entirely.
This follows the timeline proposed by the Debian/ia64 maintainer [5],
which removes support in a controlled manner, leaving IA-64 in a known
good state in the most recent LTS release. Other projects will follow
once the kernel support is removed.

[0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/
[1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/
[2] https://gridcf.org/gct-docs/latest/index.html
[3] https://cfarm.tetaneutral.net/machines/list/
[4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/
[5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/

Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: fix memory leak in krealloc failure handling

In the previous code, there was a memory leak issue where the
previously allocated memory was not freed upon a failed krealloc
operation. This patch addresses the problem by releasing the old memory
before setting the pointer to NULL in case of a krealloc failure. This
ensures that memory is properly managed and avoids potential memory
leaks.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi/unaccepted: Make sure unaccepted table is mapped

Unaccepted table is now allocated from EFI_ACPI_RECLAIM_MEMORY. It
translates into E820_TYPE_ACPI, which is not added to memblock and
therefore not mapped in the direct mapping.

This causes a crash on the first touch of the table.

Use memblock_add() to make sure that the table is mapped in direct
mapping.

Align the range to the nearest page borders. Ranges smaller than page
size are not mapped.

Fixes: e7761d827e99 ("efi/unaccepted: Use ACPI reclaim memory for unaccepted memory table")
Reported-by: Hongyu Ning <hongyu.ning@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efivarfs: expose used and total size

When writing EFI variables, one might get errors with no other message
on why it fails. Being able to see how much is used by EFI variables
helps analyzing such issues.

Since this is not a conventional filesystem, block size is intentionally
set to 1 instead of PAGE_SIZE.

x86 quirks of reserved size are taken into account; so that available
and free size can be different, further helping debugging space issues.

With this patch, one can see the remaining space in EFI variable storage
via efivarfs, like this:

$ df -h /sys/firmware/efi/efivars/
Filesystem Size Used Avail Use% Mounted on
efivarfs 176K 106K 66K 62% /sys/firmware/efi/efivars

Signed-off-by: Anisse Astier <an.astier@criteo.com>
[ardb: - rename efi_reserved_space() to efivar_reserved_space()
- whitespace/coding style tweaks]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Revert "efi: random: refresh non-volatile random seed when RNG is initialized"

This reverts commit e7b813b32a42a3a6281a4fd9ae7700a0257c1d50 (and the
subsequent fix for it: 41a15855c1ee "efi: random: fix NULL-deref when
refreshing seed").

It turns otu to cause non-deterministic boot stalls on at least a HP
6730b laptop.

Reported-and-bisected-by: Sami Korkalainen <sami.korkalainen@proton.me>
Link: https://lore.kernel.org/all/GQUnKz2al3yke5mB2i1kp3SzNHjK8vi6KJEh7rnLrOQ24OrlljeCyeWveLW9pICEmB9Qc8PKdNt3w1t_g3-Uvxq1l8Wj67PpoMeWDoH8PKk=@proton.me/
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

efi: Add unaccepted memory support

efi_config_parse_tables() reserves memory that holds unaccepted memory
configuration table so it won't be reused by page allocator.

Core-mm requires few helpers to support unaccepted memory:

- accept_memory() checks the range of addresses against the bitmap and
accept memory if needed.

- range_contains_unaccepted_memory() checks if anything within the
range requires acceptance.

Architectural code has to provide efi_get_unaccepted_table() that
returns pointer to the unaccepted memory configuration table.

arch_accept_memory() handles arch-specific part of memory acceptance.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20230606142637.5171-6-kirill.shutemov@linux.intel.com

efi/libstub: Implement support for unaccepted memory

UEFI Specification version 2.9 introduces the concept of memory
acceptance: Some Virtual Machine platforms, such as Intel TDX or AMD
SEV-SNP, requiring memory to be accepted before it can be used by the
guest. Accepting happens via a protocol specific for the Virtual
Machine platform.

Accepting memory is costly and it makes VMM allocate memory for the
accepted guest physical address range. It's better to postpone memory
acceptance until memory is needed. It lowers boot time and reduces
memory overhead.

The kernel needs to know what memory has been accepted. Firmware
communicates this information via memory map: a new memory type --
EFI_UNACCEPTED_MEMORY -- indicates such memory.

Range-based tracking works fine for firmware, but it gets bulky for
the kernel: e820 (or whatever the arch uses) has to be modified on every
page acceptance. It leads to table fragmentation and there's a limited
number of entries in the e820 table.

Another option is to mark such memory as usable in e820 and track if the
range has been accepted in a bitmap. One bit in the bitmap represents a
naturally aligned power-2-sized region of address space -- unit.

For x86, unit size is 2MiB: 4k of the bitmap is enough to track 64GiB or
physical address space.

In the worst-case scenario -- a huge hole in the middle of the
address space -- It needs 256MiB to handle 4PiB of the address
space.

Any unaccepted memory that is not aligned to unit_size gets accepted
upfront.

The bitmap is allocated and constructed in the EFI stub and passed down
to the kernel via EFI configuration table. allocate_e820() allocates the
bitmap if unaccepted memory is present, according to the size of
unaccepted region.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20230606142637.5171-4-kirill.shutemov@linux.intel.com

efi: Use standard format for printing the EFI revision

The UEFI spec section 4.2.1 describes the way the human readable EFI
revision should be constructed from the 32-bit revision field in the
system table:

The upper 16 bits of this field contain the major revision value,
and the lower 16 bits contain the minor revision value. The minor
revision values are binary coded decimals and are limited to the
range of 00..99.

When printed or displayed UEFI spec revision is referred as (Major
revision).(Minor revision upper decimal).(Minor revision lower
decimal) or (Major revision).(Minor revision upper decimal) in case
Minor revision lower decimal is set to 0.

Let's adhere to this when logging the EFI revision to the kernel log.

Note that the bit about binary coded decimals is bogus, and the minor
revision lower decimal is simply the minor revision modulo 10, given the
symbolic definitions provided by the spec itself:

#define EFI_2_40_SYSTEM_TABLE_REVISION ((2<<16) | (40))
#define EFI_2_31_SYSTEM_TABLE_REVISION ((2<<16) | (31))
#define EFI_2_30_SYSTEM_TABLE_REVISION ((2<<16) | (30))

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: Drop minimum EFI version check at boot

We currently pass a minimum major version to the generic EFI helper that
checks the system table magic and version, and refuse to boot if the
value is lower.

The motivation for this check is unknown, and even the code that uses
major version 2 as the minimum (ARM, arm64 and RISC-V) should make it
past this check without problems, and boot to a point where we have
access to a console or some other means to inform the user that the
firmware's major revision number made us unhappy. (Revision 2.0 of the
UEFI specification was released in January 2006, whereas ARM, arm64 and
RISC-V support where added in 2009, 2013 and 2017, respectively, so
checking for major version 2 or higher is completely arbitrary)

So just drop the check.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: verify that variable services are supported

Current Qualcomm UEFI firmware does not implement the variable services
but not all revisions clear the corresponding bits in the RT_PROP table
services mask and instead the corresponding calls return
EFI_UNSUPPORTED.

This leads to efi core registering the generic efivar ops even when the
variable services are not supported or when they are accessed through
some other interface (e.g. Google SMI or the upcoming Qualcomm SCM
implementation).

Instead of playing games with init call levels to make sure that the
custom implementations are registered after the generic one, make sure
that get_next_variable() is actually supported before registering the
generic ops.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: Warn if trying to reserve memory under Xen

Doing so cannot work and should never happen.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: Apply allowlist to EFI configuration tables when running under Xen

As it turns out, Xen does not guarantee that EFI boot services data
regions in memory are preserved, which means that EFI configuration
tables pointing into such memory regions may be corrupted before the
dom0 OS has had a chance to inspect them.

This is causing problems for Qubes OS when it attempts to perform system
firmware updates, which requires that the contents of the EFI System
Resource Table are valid when the fwupd userspace program runs.

However, other configuration tables such as the memory attributes table
or the runtime properties table are equally affected, and so we need a
comprehensive workaround that works for any table type.

So when running under Xen, check the EFI memory descriptor covering the
start of the table, and disregard the table if it does not reside in
memory that is preserved by Xen.

Co-developed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: xen: Implement memory descriptor lookup based on hypercall

Xen on x86 boots dom0 in EFI mode but without providing a memory map.
This means that some consistency checks we would like to perform on
configuration tables or other data structures in memory are not
currently possible. Xen does, however, expose EFI memory descriptor
info via a Xen hypercall, so let's wire that up instead. It turns out
that the returned information is not identical to what Linux's
efi_mem_desc_lookup would return: the address returned is the address
passed to the hypercall, and the size returned is the number of bytes
remaining in the configuration table. However, none of the callers of
efi_mem_desc_lookup() currently care about this. In the future, Xen may
gain a hypercall that returns the actual start address, which can be
used instead.

Co-developed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: memmap: Disregard bogus entries instead of returning them

The ESRT code currently contains two consistency checks on the memory
descriptor it obtains, but one of them is both incomplete and can only
trigger on invalid descriptors.

So let's drop these checks, and instead disregard descriptors entirely
if the start address is misaligned, or if the number of pages reaches
to or beyond the end of the address space. Note that the memory map as
a whole could still be inconsistent: multiple entries might cover the
same area, or the address could be outside of the addressable PA space,
but validating that goes beyond the scope of these helpers. Also note
that since the physical address space is never 64-bits wide, a
descriptor that includes the last page of memory is not valid. This is
fortunate, since it means that a valid physical address will never be an
error pointer and that the length of a memory descriptor in bytes will
fit in a 64-bit unsigned integer.

Co-developed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: efivars: drop kobject from efivars_register()

Since commit 0f5b2c69a4cb ("efi: vars: Remove deprecated 'efivars' sysfs
interface") and the removal of the sysfs interface there are no users of
the efivars kobject.

Drop the kobject argument from efivars_register() and add a new
efivar_is_available() helper in favour of the old efivars_kobject().

Note that the new helper uses the prefix 'efivar' (i.e. without an 's')
for consistency with efivar_supports_writes() and the rest of the
interface (except the registration functions).

For the benefit of drivers with optional EFI support, also provide a
dummy implementation of efivar_is_available().

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: fix potential NULL deref in efi_mem_reserve_persistent

When iterating on a linked list, a result of memremap is dereferenced
without checking it for NULL.

This patch adds a check that falls back on allocating a new page in
case memremap doesn't succeed.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 18df7577adae ("efi/memreserve: deal with memreserve entries in unmapped memory")
Signed-off-by: Anton Gusev <aagusev@ispras.ru>
[ardb: return -ENOMEM instead of breaking out of the loop]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: fix NULL-deref in init error path

In cases where runtime services are not supported or have been disabled,
the runtime services workqueue will never have been allocated.

Do not try to destroy the workqueue unconditionally in the unlikely
event that EFI initialisation fails to avoid dereferencing a NULL
pointer.

Fixes: 98086df8b70c ("efi: add missed destroy_workqueue when efisubsys_init fails")
Cc: stable@vger.kernel.org
Cc: Li Heng <liheng40@huawei.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: random: fix NULL-deref when refreshing seed

Do not try to refresh the RNG seed in case the firmware does not support
setting variables.

This is specifically needed to prevent a NULL-pointer dereference on the
Lenovo X13s with some firmware revisions, or more generally, whenever
the runtime services have been disabled (e.g. efi=noruntime or with
PREEMPT_RT).

Fixes: e7b813b32a42 ("efi: random: refresh non-volatile random seed when RNG is initialized")
Reported-by: Steev Klimaszewski <steev@kali.org>
Reported-by: Bjorn Andersson <andersson@kernel.org>
Tested-by: Steev Klimaszewski <steev@kali.org>
Tested-by: Andrew Halaney <ahalaney@redhat.com> # sc8280xp-lenovo-thinkpad-x13s
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

efi: random: refresh non-volatile random seed when RNG is initialized

EFI has a rather unique benefit that it has access to some limited
non-volatile storage, where the kernel can store a random seed. Register
a notification for when the RNG is initialized, and at that point, store
a new random seed.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

efi: random: combine bootloader provided RNG seed with RNG protocol output

Instead of blindly creating the EFI random seed configuration table if
the RNG protocol is implemented and works, check whether such a EFI
configuration table was provided by an earlier boot stage and if so,
concatenate the existing and the new seeds, leaving it up to the core
code to mix it in and credit it the way it sees fit.

This can be used for, e.g., systemd-boot, to pass an additional seed to
Linux in a way that can be consumed by the kernel very early. In that
case, the following definitions should be used to pass the seed to the
EFI stub:

struct linux_efi_random_seed {
u32 size; // of the 'seed' array in bytes
u8 seed[];
};

The memory for the struct must be allocated as EFI_ACPI_RECLAIM_MEMORY
pool memory, and the address of the struct in memory should be installed
as a EFI configuration table using the following GUID:

LINUX_EFI_RANDOM_SEED_TABLE_GUID 1ce1e5bc-7ceb-42f2-81e5-8aadf180f57b

Note that doing so is safe even on kernels that were built without this
patch applied, but the seed will simply be overwritten with a seed
derived from the EFI RNG protocol, if available. The recommended seed
size is 32 bytes, and seeds larger than 512 bytes are considered
corrupted and ignored entirely.

In order to preserve forward secrecy, seeds from previous bootloaders
are memzero'd out, and in order to preserve memory, those older seeds
are also freed from memory. Freeing from memory without first memzeroing
is not safe to do, as it's possible that nothing else will ever
overwrite those pages used by EFI.

Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
[ardb: incorporate Jason's followup changes to extend the maximum seed
size on the consumer end, memzero() it and drop a needless printk]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: x86: Move EFI runtime map sysfs code to arch/x86

The EFI runtime map code is only wired up on x86, which is the only
architecture that has a need for it in its implementation of kexec.

So let's move this code under arch/x86 and drop all references to it
from generic code. To ensure that the efi_runtime_map_init() is invoked
at the appropriate time use a 'sync' subsys_initcall() that will be
called right after the EFI initcall made from generic code where the
original invocation of efi_runtime_map_init() resided.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Dave Young <dyoung@redhat.com>

efi: libstub: Move screen_info handling to common code

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>

efi: random: reduce seed size to 32 bytes

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>

efi: ssdt: Don't free memory if ACPI table was loaded successfully

Amadeusz reports KASAN use-after-free errors introduced by commit
3881ee0b1edc ("efi: avoid efivars layer when loading SSDTs from
variables"). The problem appears to be that the memory that holds the
new ACPI table is now freed unconditionally, instead of only when the
ACPI core reported a failure to load the table.

So let's fix this, by omitting the kfree() on success.

Cc: <stable@vger.kernel.org> # v6.0
Link: https://lore.kernel.org/all/a101a10a-4fbb-5fae-2e3c-76cf96ed8fbd@linux.intel.com/
Fixes: 3881ee0b1edc ("efi: avoid efivars layer when loading SSDTs from variables")
Reported-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: libstub: unify initrd loading between architectures

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>

mm: remove rb tree.

Remove the RB tree and start using the maple tree for vm_area_struct
tracking.

Drop validate_mm() calls in expand_upwards() and expand_downwards() as the
lock is not held.

Link: https://lkml.kernel.org/r/20220906194824.2110408-18-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: start tracking VMAs with maple tree

Start tracking the VMAs with the new maple tree structure in parallel with
the rb_tree. Add debug and trace events for maple tree operations and
duplicate the rb_tree that is created on forks into the maple tree.

The maple tree is added to the mm_struct including the mm_init struct,
added support in required mm/mmap functions, added tracking in kernel/fork
for process forking, and used to find the unmapped_area and checked
against what the rbtree finds.

This also moves the mmap_lock() in exit_mmap() since the oom reaper call
does walk the VMAs. Otherwise lockdep will be unhappy if oom happens.

When splitting a vma fails due to allocations of the maple tree nodes,
the error path in __split_vma() calls new->vm_ops->close(new). The page
accounting for hugetlb is actually in the close() operation, so it
accounts for the removal of 1/2 of the VMA which was not adjusted. This
results in a negative exit value. To avoid the negative charge, set
vm_start = vm_end and vm_pgoff = 0.

There is also a potential accounting issue in special mappings from
insert_vm_struct() failing to allocate, so reverse the charge there in
the failure scenario.

Link: https://lkml.kernel.org/r/20220906194824.2110408-9-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

efi: vars: Move efivar caching layer into efivarfs

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>

efi: avoid efivars layer when loading SSDTs from variables

The efivars intermediate variable access layer provides an abstraction
that permits the EFI variable store to be replaced by something else
that implements a compatible interface, and caches all variables in the
variable store for fast access via the efivarfs pseudo-filesystem.

The SSDT override feature does not take advantage of either feature, as
it is only used when the generic EFI implementation of efivars is used,
and it traverses all variables only once to find the ones it is
interested in, and frees all data structures that the efivars layer
keeps right after.

So in this case, let's just call EFI's code directly, using the function
pointers in struct efi.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: Make code to find mirrored memory ranges generic

Commit b05b9f5f9dcf ("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>

efi: Register efi_secret platform device if EFI secret area is declared

During efi initialization, check if coco_secret is defined in the EFI
configuration table; in such case, register platform device
"efi_secret". This allows udev to automatically load the efi_secret
module (platform driver), which in turn will populate the
<securityfs>/secrets/coco directory in guests into which secrets were
injected.

Note that a declared address of an EFI secret area doesn't mean that
secrets where indeed injected to that area; if the secret area is not
populated, the driver will not load (but the platform device will still
be registered).

Signed-off-by: Dov Murik <dovmurik@linux.ibm.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://lore.kernel.org/r/20220412212127.154182-4-dovmurik@linux.ibm.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: Save location of EFI confidential computing area

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>

efi: Allow to enable EFI runtime services by default on RT

Commit d9f283ae71af ("efi: Disable runtime services on RT") disabled EFI
runtime services by default when the CONFIG_PREEMPT_RT option is enabled.

The rationale for that commit is that some EFI calls could take too much
time, leading to large latencies which is an issue for Real-Time kernels.

But a side effect of that change was that now is not possible anymore to
enable the EFI runtime services by default when CONFIG_PREEMPT_RT is set,
without passing an efi=runtime command line parameter to the kernel.

Instead, let's add a new EFI_DISABLE_RUNTIME boolean Kconfig option, that
would be set to n by default but to y if CONFIG_PREEMPT_RT is enabled.

That way, the current behaviour is preserved but gives users a mechanism
to enable the EFI runtimes services in their kernels if that is required.
For example, if the firmware could guarantee bounded time for EFI calls.

Also, having a separate boolean config could allow users to disable the
EFI runtime services by default even when CONFIG_PREEMPT_RT is not set.

Reported-by: Alexander Larsson <alexl@redhat.com>
Fixes: d9f283ae71af ("efi: Disable runtime services on RT")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20220331151654.184433-1-javierm@redhat.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: fix return value of __setup handlers

When "dump_apple_properties" is used on the kernel boot command line,
it causes an Unknown parameter message and the string is added to init's
argument strings:

Unknown kernel command line parameters "dump_apple_properties
BOOT_IMAGE=/boot/bzImage-517rc6 efivar_ssdt=newcpu_ssdt", will be
passed to user space.

Run /sbin/init as init process
with arguments:
/sbin/init
dump_apple_properties
with environment:
HOME=/
TERM=linux
BOOT_IMAGE=/boot/bzImage-517rc6
efivar_ssdt=newcpu_ssdt

Similarly when "efivar_ssdt=somestring" is used, it is added to the
Unknown parameter message and to init's environment strings, polluting
them (see examples above).

Change the return value of the __setup functions to 1 to indicate
that the __setup options have been handled.

Fixes: 58c5475aba67 ("x86/efi: Retrieve and assign Apple device properties")
Fixes: 475fb4e8b2f4 ("efi / ACPI: load SSTDs from EFI variables")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Octavian Purdila <octavian.purdila@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Link: https://lore.kernel.org/r/20220301041851.12459-1-rdunlap@infradead.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: runtime: avoid EFIv2 runtime services on Apple x86 machines

Aditya reports [0] that his recent MacbookPro crashes in the firmware
when using the variable services at runtime. The culprit appears to be a
call to QueryVariableInfo(), which we did not use to call on Apple x86
machines in the past as they only upgraded from EFI v1.10 to EFI v2.40
firmware fairly recently, and QueryVariableInfo() (along with
UpdateCapsule() et al) was added in EFI v2.00.

The only runtime service introduced in EFI v2.00 that we actually use in
Linux is QueryVariableInfo(), as the capsule based ones are optional,
generally not used at runtime (all the LVFS/fwupd firmware update
infrastructure uses helper EFI programs that invoke capsule update at
boot time, not runtime), and not implemented by Apple machines in the
first place. QueryVariableInfo() is used to 'safely' set variables,
i.e., only when there is enough space. This prevents machines with buggy
firmwares from corrupting their NVRAMs when they run out of space.

Given that Apple machines have been using EFI v1.10 services only for
the longest time (the EFI v2.0 spec was released in 2006, and Linux
support for the newly introduced runtime services was added in 2011, but
the MacbookPro12,1 released in 2015 still claims to be EFI v1.10 only),
let's avoid the EFI v2.0 ones on all Apple x86 machines.

[0] https://lore.kernel.org/all/6D757C75-65B1-468B-842D-10410081A8E4@live.com/

Cc: <stable@vger.kernel.org>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Reported-by: Aditya Garg <gargaditya08@live.com>
Tested-by: Orlando Chamberlain <redecorating@protonmail.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Aditya Garg <gargaditya08@live.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215277

efi: Allow efi=runtime

In case the command line option "efi=noruntime" is default at built-time, the user
could overwrite its state by `efi=runtime' and allow it again.

This is useful on PREEMPT_RT where "efi=noruntime" is default and the
user might need to alter the boot order for instance.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: Disable runtime services on RT

Based on measurements the EFI functions get_variable /
get_next_variable take up to 2us which looks okay.
The functions get_time, set_time take around 10ms. These 10ms are too
much. Even one ms would be too much.
Ard mentioned that SetVariable might even trigger larger latencies if
the firmware will erase flash blocks on NOR.

The time-functions are used by efi-rtc and can be triggered during
run-time (either via explicit read/write or ntp sync).

The variable write could be used by pstore.
These functions can be disabled without much of a loss. The poweroff /
reboot hooks may be provided by PSCI.

Disable EFI's runtime wrappers on PREEMPT_RT.

This was observed on "EFI v2.60 by SoftIron Overdrive 1000".

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

firmware/efi: Tell memblock about EFI iomem reservations

kexec_load_file() relies on the memblock infrastructure to avoid
stamping over regions of memory that are essential to the survival
of the system.

However, nobody seems to agree how to flag these regions as reserved,
and (for example) EFI only publishes its reservations in /proc/iomem
for the benefit of the traditional, userspace based kexec tool.

On arm64 platforms with GICv3, this can result in the payload being
placed at the location of the LPI tables. Shock, horror!

Let's augment the EFI reservation code with a memblock_reserve() call,
protecting our dear tables from the secondary kernel invasion.

Reported-by: Moritz Fischer <mdf@kernel.org>
Tested-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

firmware/efi: Fix a use after bug in efi_mem_reserve_persistent

In the for loop in efi_mem_reserve_persistent(), prsv = rsv->next
use the unmapped rsv. Use the unmapped pages will cause segment
fault.

Fixes: 18df7577adae6 ("efi/memreserve: deal with memreserve entries in unmapped memory")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

mm/gup: prevent gup_fast from racing with COW during fork

Since commit 70e806e4e645 ("mm: Do early cow for pinned pages during
fork() for ptes") pages under a FOLL_PIN will not be write protected
during COW for fork. This means that pages returned from
pin_user_pages(FOLL_WRITE) should not become write protected while the pin
is active.

However, there is a small race where get_user_pages_fast(FOLL_PIN) can
establish a FOLL_PIN at the same time copy_present_page() is write
protecting it:

CPU 0 CPU 1
get_user_pages_fast()
internal_get_user_pages_fast()
copy_page_range()
pte_alloc_map_lock()
copy_present_page()
atomic_read(has_pinned) == 0
page_maybe_dma_pinned() == false
atomic_set(has_pinned, 1);
gup_pgd_range()
gup_pte_range()
pte_t pte = gup_get_pte(ptep)
pte_access_permitted(pte)
try_grab_compound_head()
pte = pte_wrprotect(pte)
set_pte_at();
pte_unmap_unlock()
// GUP now returns with a write protected page

The first attempt to resolve this by using the write protect caused
problems (and was missing a barrrier), see commit f3c64eda3e50 ("mm: avoid
early COW write protect games during fork()")

Instead wrap copy_p4d_range() with the write side of a seqcount and check
the read side around gup_pgd_range(). If there is a collision then
get_user_pages_fast() fails and falls back to slow GUP.

Slow GUP is safe against this race because copy_page_range() is only
called while holding the exclusive side of the mmap_lock on the src
mm_struct.

[akpm@linux-foundation.org: coding style fixes]
Link: https://lore.kernel.org/r/CAHk-=wi=iCnYCARbPGjkVJu9eyYeZ13N64tZYLdOB8CP5Q_PLw@mail.gmail.com

Link: https://lkml.kernel.org/r/2-v4-908497cf359a+4782-gup_fork_jgg@nvidia.com
Fixes: f3c64eda3e50 ("mm: avoid early COW write protect games during fork()")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: "Ahmed S. Darwish" <a.darwish@linutronix.de> [seqcount_t parts]
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

efi/efivars: Set generic ops before loading SSDT

Efivars allows for overriding of SSDT tables, however starting with
commit

bf67fad19e493b ("efi: Use more granular check for availability for variable services")

this use case is broken. When loading SSDT generic ops should be set
first, however mentioned commit reversed order of operations. Fix this
by restoring original order of operations.

Fixes: bf67fad19e493b ("efi: Use more granular check for availability for variable services")
Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Link: https://lore.kernel.org/r/20201123172817.124146-1-amadeuszx.slawinski@linux.intel.com
Tested-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: Add definition of EFI_MEMORY_CPU_CRYPTO and ability to report it

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>

efi: Support for MOK variable config table

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>

efi: add missed destroy_workqueue when efisubsys_init fails

destroy_workqueue() should be called to destroy efi_rts_wq
when efisubsys_init() init resources fails.

Cc: <stable@vger.kernel.org>
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Li Heng <liheng40@huawei.com>
Link: https://lore.kernel.org/r/1595229738-10087-1-git-send-email-liheng40@huawei.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi/efivars: Expose RT service availability via efivars abstraction

Commit

bf67fad19e493b ("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: bf67fad19e493b ("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>

efi: Make it possible to disable efivar_ssdt entirely

In most cases, such as CONFIG_ACPI_CUSTOM_DSDT and
CONFIG_ACPI_TABLE_UPGRADE, boot-time modifications to firmware tables
are tied to specific Kconfig options. Currently this is not the case
for modifying the ACPI SSDT via the efivar_ssdt kernel command line
option and associated EFI variable.

This patch adds CONFIG_EFI_CUSTOM_SSDT_OVERLAYS, which defaults
disabled, in order to allow enabling or disabling that feature during
the build.

Cc: <stable@vger.kernel.org>
Signed-off-by: Peter Jones <pjones@redhat.com>
Link: https://lore.kernel.org/r/20200615202408.2242614-1-pjones@redhat.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: Replace zero-length array and use struct_size() helper

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 76497732932f ("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>

mmap locking API: add MMAP_LOCK_INITIALIZER

Define a new initializer for the mmap locking api. Initially this just
evaluates to __RWSEM_INITIALIZER as the API is defined as wrappers around
rwsem.

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-9-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

efi: Pull up arch-specific prototype efi_systab_show_arch()

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>

efi: Move arch_tables check to caller

Instead of making match_config_table() test its table_types pointer for
NULL-ness, omit the call entirely if no arch_tables pointer was provided
to efi_config_parse_tables().

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: Clean up config table description arrays

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>

efi/x86: Ignore the memory attributes table on i386

Commit:

3a6b6c6fb23667fa ("efi: Make EFI_MEMORY_ATTRIBUTES_TABLE initialization common across all architectures")

moved the call to efi_memattr_init() from ARM specific to the generic
EFI init code, in order to be able to apply the restricted permissions
described in that table on x86 as well.

We never enabled this feature fully on i386, and so mapping and
reserving this table is pointless. However, due to the early call to
memblock_reserve(), the memory bookkeeping gets confused to the point
where it produces the splat below when we try to map the memory later
on:

------------[ cut here ]------------
ioremap on RAM at 0x3f251000 - 0x3fa1afff
WARNING: CPU: 0 PID: 0 at arch/x86/mm/ioremap.c:166 __ioremap_caller ...
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.20.0 #48
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
EIP: __ioremap_caller.constprop.0+0x249/0x260
Code: 90 0f b7 05 4e 38 40 de 09 45 e0 e9 09 ff ff ff 90 8d 45 ec c6 05 ...
EAX: 00000029 EBX: 00000000 ECX: de59c228 EDX: 00000001
ESI: 3f250fff EDI: 00000000 EBP: de3edf20 ESP: de3edee0
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00200296
CR0: 80050033 CR2: ffd17000 CR3: 1e58c000 CR4: 00040690
Call Trace:
ioremap_cache+0xd/0x10
? old_map_region+0x72/0x9d
old_map_region+0x72/0x9d
efi_map_region+0x8/0xa
efi_enter_virtual_mode+0x260/0x43b
start_kernel+0x329/0x3aa
i386_start_kernel+0xa7/0xab
startup_32_smp+0x164/0x168
---[ end trace e15ccf6b9f356833 ]---

Let's work around this by disregarding the memory attributes table
altogether on i386, which does not result in a loss of functionality
or protection, given that we never consumed the contents.

Fixes: 3a6b6c6fb23667fa ("efi: Make EFI_MEMORY_ATTRIBUTES_TABLE ... ")
Tested-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200304165917.5893-1-ardb@kernel.org
Link: https://lore.kernel.org/r/20200308080859.21568-21-ardb@kernel.org

efi: Export boot-services code and data as debugfs-blobs

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>

efi: Mark all EFI runtime services as unsupported on non-EFI boot

Recent changes to the way we deal with EFI runtime services that
are marked as unsupported by the firmware resulted in a regression
for non-EFI boot. The problem is that all EFI runtime services are
marked as available by default, and any non-NULL checks on the EFI
service function pointers (which will be non-NULL even for runtime
services that are unsupported on an EFI boot) were replaced with
checks against the mask stored in efi.runtime_supported_mask.

When doing a non-EFI boot, this check against the mask will return
a false positive, given the fact that all runtime services are
marked as enabled by default. Since we dropped the non-NULL check
of the runtime service function pointer in favor of the mask check,
we will now unconditionally dereference the function pointer, even
if it is NULL, and go boom.

So let's ensure that the mask reflects reality on a non-EFI boot,
which is that all EFI runtime services are unsupported.

Reported-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-efi@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20200228121408.9075-7-ardb@kernel.org

efi: Don't shadow 'i' in efi_config_parse_tables()

Shadowing variables is generally frowned upon.

Let's simply reuse the existing loop counter 'i' instead of shadowing it.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-efi@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20200223221324.156086-1-xypron.glpk@gmx.de
Link: https://lore.kernel.org/r/20200228121408.9075-4-ardb@kernel.org

efi/x86: Add RNG seed EFI table to unencrypted mapping check

When booting with SME active, EFI tables must be mapped unencrypted since
they were built by UEFI in unencrypted memory. Update the list of tables
to be checked during early_memremap() processing to account for the EFI
RNG seed table.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-efi@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Link: https://lore.kernel.org/r/b64385fc13e5d7ad4b459216524f138e7879234f.1582662842.git.thomas.lendacky@amd.com
Link: https://lore.kernel.org/r/20200228121408.9075-3-ardb@kernel.org

efi: READ_ONCE rng seed size before munmap

This function is consistent with using size instead of seed->size
(except for one place that this patch fixes), but it reads seed->size
without using READ_ONCE, which means the compiler might still do
something unwanted. So, this commit simply adds the READ_ONCE
wrapper.

Fixes: 636259880a7e ("efi: Add support for seeding the RNG from a UEFI ...")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-efi@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200217123354.21140-1-Jason@zx2c4.com
Link: https://lore.kernel.org/r/20200221084849.26878-5-ardb@kernel.org

efi: Register EFI rtc platform device only when available

Drop the separate driver that registers the EFI rtc on all EFI
systems that have runtime services available, and instead, move
the registration into the core EFI code, and make it conditional
on whether the actual time related services are available.

Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: Use more granular check for availability for variable services

The UEFI spec rev 2.8 permits firmware implementations to support only
a subset of EFI runtime services at OS runtime (i.e., after the call to
ExitBootServices()), so let's take this into account in the drivers that
rely specifically on the availability of the EFI variable services.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi: Add support for EFI_RT_PROPERTIES table

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>

efi: Store mask of supported runtime services in struct efi

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>

efi/arm: Move FDT param discovery code out of efi.c

On ARM systems, we discover the UEFI system table address and memory
map address from the /chosen node in the device tree, or in the Xen
case, from a similar node under /hypervisor.

Before making some functional changes to that code, move it into its
own file that only gets built if CONFIG_EFI_PARAMS_FROM_FDT=y.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

efi/x86: Make fw_vendor, config_table and runtime sysfs nodes x86 specific

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>

efi: Clean up config_parse_tables()

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>

efi: Make efi_config_init() x86 only

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>

efi: Merge EFI system table revision and vendor checks

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>

efi: Make memreserve table handling local to efi.c

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>

efi: Move mem_attr_table out of struct efi

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>

efi: Make rng_seed table handling local to efi.c

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>

efi: Move UGA and PROP table handling to x86 code

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>

efi/ia64: Move HCDP and MPS table handling into IA64 arch code

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>

efi: Drop handling of 'boot_info' configuration table

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>

efi: Fix comment for efi_mem_type() wrt absent physical addresses

A previous commit f99afd08a45f ("efi: Update efi_mem_type() to return an
error rather than 0") changed the return value from EFI_RESERVED_TYPE to
-EINVAL when the searched physical address is not present in any memory
descriptor. But the comment preceding the function never changed. Let's
change the comment now to reflect the new return value -EINVAL.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200113172245.27925-10-ardb@kernel.org

treewide: Use sizeof_field() macro

Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except
at places where these are defined. Later patches will remove the unused
definition of FIELD_SIZEOF().

This patch is generated using following script:

EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h"

git grep -l -e "\bFIELD_SIZEOF\b" | while read file;
do

if [[ "$file" =~ $EXCLUDE_FILES ]]; then
continue
fi
sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file;
done

Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: David Miller <davem@davemloft.net> # for net

efi/memreserve: Register reservations as 'reserved' in /proc/iomem

Memory regions that are reserved using efi_mem_reserve_persistent()
are recorded in a special EFI config table which survives kexec,
allowing the incoming kernel to honour them as well. However,
such reservations are not visible in /proc/iomem, and so the kexec
tools that load the incoming kernel and its initrd into memory may
overwrite these reserved regions before the incoming kernel has a
chance to reserve them from further use.

Address this problem by adding these reservations to /proc/iomem as
they are created. Note that reservations that are inherited from a
previous kernel are memblock_reserve()'d early on, so they are already
visible in /proc/iomem.

Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com>
Cc: <stable@vger.kernel.org> # v5.4+
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191206165542.31469-2-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Common enable/disable infrastructure for EFI soft reservation

UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the
interpretation of the EFI Memory Types as "reserved for a specific
purpose".

The proposed Linux behavior for specific purpose memory is that it is
reserved for direct-access (device-dax) by default and not available for
any kernel usage, not even as an OOM fallback. Later, through udev
scripts or another init mechanism, these device-dax claimed ranges can
be reconfigured and hot-added to the available System-RAM with a unique
node identifier. This device-dax management scheme implements "soft" in
the "soft reserved" designation by allowing some or all of the
reservation to be recovered as typical memory. This policy can be
disabled at compile-time with CONFIG_EFI_SOFT_RESERVE=n, or runtime with
efi=nosoftreserve.

As for this patch, define the common helpers to determine if the
EFI_MEMORY_SP attribute should be honored. The determination needs to be
made early to prevent the kernel from being loaded into soft-reserved
memory, or otherwise allowing early allocations to land there. Follow-on
changes are needed per architecture to leverage these helpers in their
respective mem-init paths.

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

efi: Enumerate EFI_MEMORY_SP

UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the
interpretation of the EFI Memory Types as "reserved for a specific
purpose". The intent of this bit is to allow the OS to identify precious
or scarce memory resources and optionally manage it separately from
EfiConventionalMemory. As defined older OSes that do not know about this
attribute are permitted to ignore it and the memory will be handled
according to the OS default policy for the given memory type.

In other words, this "specific purpose" hint is deliberately weaker than
EfiReservedMemoryType in that the system continues to operate if the OS
takes no action on the attribute. The risk of taking no action is
potentially unwanted / unmovable kernel allocations from the designated
resource that prevent the full realization of the "specific purpose".
For example, consider a system with a high-bandwidth memory pool. Older
kernels are permitted to boot and consume that memory as conventional
"System-RAM" newer kernels may arrange for that memory to be set aside
(soft reserved) by the system administrator for a dedicated
high-bandwidth memory aware application to consume.

Specifically, this mechanism allows for the elimination of scenarios
where platform firmware tries to game OS policy by lying about ACPI SLIT
values, i.e. claiming that a precious memory resource has a high
distance to trigger the OS to avoid it by default. This reservation hint
allows platform-firmware to instead tell the truth about performance
characteristics by indicate to OS memory management to put immovable
allocations elsewhere.

Implement simple detection of the bit for EFI memory table dumps and
save the kernel policy for a follow-on change.

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

efi/random: Treat EFI_RNG_PROTOCOL output as bootloader randomness

Commit 428826f5358c ("fdt: add support for rng-seed") introduced
add_bootloader_randomness(), permitting randomness provided by the
bootloader or firmware to be credited as entropy. However, the fact
that the UEFI support code was already wired into the RNG subsystem
via a call to add_device_randomness() was overlooked, and so it was
not converted at the same time.

Note that this UEFI (v2.4 or newer) feature is currently only
implemented for EFI stub booting on ARM, and further note that
CONFIG_RANDOM_TRUST_BOOTLOADER must be enabled, and this should be
done only if there indeed is sufficient trust in the bootloader
_and_ its source of randomness.

[ ardb: update commit log ]

Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191029173755.27149-4-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

ACPICA: make acpi_load_table() return table index

ACPICA commit d1716a829d19be23277d9157c575a03b9abb7457

For unloading an ACPI table, it is necessary to provide the index of
the table. The method intended for dynamically loading or hotplug
addition of tables, acpi_load_table(), should provide this information
via an optional pointer to the loaded table index.

This patch fixes the table unload function of acpi_configfs.

Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Fixes: d06c47e3dd07f ("ACPI: configfs: Resolve objects on host-directed table loads")
Link: https://github.com/acpica/acpica/commit/d1716a82
Signed-off-by: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de>
Signed-off-by: Erik Schmauss <erik.schmauss@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

efivar/ssdt: Don't iterate over EFI vars if no SSDT override was specified

The kernel command line option efivar_ssdt= allows the name to be
specified of an EFI variable containing an ACPI SSDT table that should
be loaded into memory by the OS, and treated as if it was provided by
the firmware.

Currently, that code will always iterate over the EFI variables and
compare each name with the provided name, even if the command line
option wasn't set to begin with.

So bail early when no variable name was provided. This works around a
boot regression on the 2012 Mac Pro, as reported by Scott.

Tested-by: Scott Talbert <swt@techie.net>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: <stable@vger.kernel.org> # v4.9+
Cc: Ben Dooks <ben.dooks@codethink.co.uk>
Cc: Dave Young <dyoung@redhat.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Jerry Snitselaar <jsnitsel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Matthew Garrett <mjg59@google.com>
Cc: Octavian Purdila <octavian.purdila@intel.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
Fixes: 475fb4e8b2f4 ("efi / ACPI: load SSTDs from EFI variables")
Link: https://lkml.kernel.org/r/20191002165904.8819-3-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Restrict efivar_ssdt_load when the kernel is locked down

efivar_ssdt_load allows the kernel to import arbitrary ACPI code from an
EFI variable, which gives arbitrary code execution in ring 0. Prevent
that when the kernel is locked down.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-efi@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>

efi: Export Runtime Configuration Interface table to sysfs

System firmware advertises the address of the 'Runtime
Configuration Interface table version 2 (RCI2)' via
an EFI Configuration Table entry. This code retrieves the RCI2
table from the address and exports it to sysfs as a binary
attribute 'rci2' under /sys/firmware/efi/tables directory.
The approach adopted is similar to the attribute 'DMI' under
/sys/firmware/dmi/tables.

RCI2 table contains BIOS HII in XML format and is used to populate
BIOS setup page in Dell EMC OpenManage Server Administrator tool.
The BIOS setup page contains BIOS tokens which can be configured.

Signed-off-by: Narendra K <Narendra.K@dell.com>
Reviewed-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

efi: ia64: move SAL systab handling out of generic EFI code

The SAL systab is an Itanium specific EFI configuration table, so
move its handling into arch/ia64 where it belongs.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

efi/x86: move UV_SYSTAB handling into arch/x86

The SGI UV UEFI machines are tightly coupled to the x86 architecture
so there is no need to keep any awareness of its existence in the
generic EFI layer, especially since we already have the infrastructure
to handle arch-specific configuration tables, and were even already
using it to some extent.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

efi: x86: move efi_is_table_address() into arch/x86

The function efi_is_table_address() and the associated array of table
pointers is specific to x86. Since we will be adding some more x86
specific tables, let's move this code out of the generic code first.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

tpm: Reserve the TPM final events table

UEFI systems provide a boot services protocol for obtaining the TPM
event log, but this is unusable after ExitBootServices() is called.
Unfortunately ExitBootServices() itself triggers additional TPM events
that then can't be obtained using this protocol. The platform provides a
mechanism for the OS to obtain these events by recording them to a
separate UEFI configuration table which the OS can then map.

Unfortunately this table isn't self describing in terms of providing its
length, so we need to parse the events inside it to figure out how long
it is. Since the table isn't mapped at this point, we need to extend the
length calculation function to be able to map the event as it goes
along.

(Fixes by Bartosz Szczepanek <bsz@semihalf.com>)

Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Bartosz Szczepanek <bsz@semihalf.com>
Tested-by: Bartosz Szczepanek <bsz@semihalf.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

efi/memreserve: deal with memreserve entries in unmapped memory

Ensure that the EFI memreserve entries can be accessed, even if they
are located in memory that the kernel (e.g., a crashkernel) omits from
the linear map.

Fixes: 80424b02d42b ("efi: Reduce the amount of memblock reservations ...")
Cc: <stable@vger.kernel.org> # 5.0+
Reported-by: Jonathan Richardson <jonathan.richardson@broadcom.com>
Reviewed-by: Jonathan Richardson <jonathan.richardson@broadcom.com>
Tested-by: Jonathan Richardson <jonathan.richardson@broadcom.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428

Based on 1 normalized pattern(s):

this file is released under the gplv2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 68 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

efi: Allow the number of EFI configuration tables entries to be zero

Only try and access the EFI configuration tables if there there are any
reported. This allows EFI to be continued to used on systems where there
are no configuration table entries.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Gen Zhang <blackgod016574@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190525112559.7917-3-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi/arm: Revert "Defer persistent reservations until after paging_init()"

This reverts commit eff896288872d687d9662000ec9ae11b6d61766f, which
deferred the processing of persistent memory reservations to a point
where the memory may have already been allocated and overwritten,
defeating the purpose.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190215123333.21209-3-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Reduce the amount of memblock reservations for persistent allocations

The current implementation of efi_mem_reserve_persistent() is rather
naive, in the sense that for each invocation, it creates a separate
linked list entry to describe the reservation. Since the linked list
entries themselves need to persist across subsequent kexec reboots,
every reservation created this way results in two memblock_reserve()
calls at the next boot.

On arm64 systems with 100s of CPUs, this may result in a excessive
number of memblock reservations, and needless fragmentation.

So instead, make use of the newly updated struct linux_efi_memreserve
layout to put multiple reservations into a single linked list entry.
This should get rid of the numerous tiny memblock reservations, and
effectively cut the total number of reservations in half on arm64
systems with many CPUs.

[ mingo: build warning fix. ]

Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arend van Spriel <arend.vanspriel@broadcom.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Snowberg <eric.snowberg@oracle.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: YiFei Zhu <zhuyifei1999@gmail.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181129171230.18699-11-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Permit multiple entries in persistent memreserve data structure

In preparation of updating efi_mem_reserve_persistent() to cause less
fragmentation when dealing with many persistent reservations, update
the struct definition and the code that handles it currently so it
can describe an arbitrary number of reservations using a single linked
list entry. The actual optimization will be implemented in a subsequent
patch.

Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arend van Spriel <arend.vanspriel@broadcom.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Snowberg <eric.snowberg@oracle.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: YiFei Zhu <zhuyifei1999@gmail.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181129171230.18699-10-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Prevent GICv3 WARN() by mapping the memreserve table before first use

Mapping the MEMRESERVE EFI configuration table from an early initcall
is too late: the GICv3 ITS code that creates persistent reservations
for the boot CPU's LPI tables is invoked from init_IRQ(), which runs
much earlier than the handling of the initcalls. This results in a
WARN() splat because the LPI tables cannot be reserved persistently,
which will result in silent memory corruption after a kexec reboot.

So instead, invoke the initialization performed by the initcall from
efi_mem_reserve_persistent() itself as well, but keep the initcall so
that the init is guaranteed to have been called before SMP boot.

Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Jan Glauber <jglauber@cavium.com>
Tested-by: John Garry <john.garry@huawei.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 63eb322d89c8 ("efi: Permit calling efi_mem_reserve_persistent() ...")
Link: http://lkml.kernel.org/r/20181123215132.7951-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Permit calling efi_mem_reserve_persistent() from atomic context

Currently, efi_mem_reserve_persistent() may not be called from atomic
context, since both the kmalloc() call and the memremap() call may
sleep.

The kmalloc() call is easy enough to fix, but the memremap() call
needs to be moved into an init hook since we cannot control the
memory allocation behavior of memremap() at the call site.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181114175544.12860-6-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi/arm: Defer persistent reservations until after paging_init()

The new memory EFI reservation feature we introduced to allow memory
reservations to persist across kexec may trigger an unbounded number
of calls to memblock_reserve(). The memblock subsystem can deal with
this fine, but not before memblock resizing is enabled, which we can
only do after paging_init(), when the memory we reallocate the array
into is actually mapped.

So break out the memreserve table processing into a separate routine
and call it after paging_init() on arm64. On ARM, because of limited
reviewing bandwidth of the maintainer, we cannot currently fix this,
so instead, disable the EFI persistent memreserve entirely on ARM so
we can fix it later.

Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181114175544.12860-5-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: add API to reserve memory persistently across kexec reboot

Add kernel plumbing to reserve memory regions persistently on a EFI
system by adding entries to the MEMRESERVE linked list.

Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

efi: honour memory reservations passed via a linux specific config table

In order to allow the OS to reserve memory persistently across a
kexec, introduce a Linux-specific UEFI configuration table that
points to the head of a linked list in memory, allowing each kernel
to add list items describing memory regions that the next kernel
should treat as reserved.

This is useful, e.g., for GICv3 based ARM systems that cannot disable
DMA access to the LPI tables, forcing them to reuse the same memory
region again after a kexec reboot.

Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids

The mm_struct always contains a cpumask bitmap, regardless of
CONFIG_CPUMASK_OFFSTACK. That means the first step can be to
simplify things, and simply have one bitmask at the end of the
mm_struct for the mm_cpumask.

This does necessitate moving everything else in mm_struct into
an anonymous sub-structure, which can be randomized when struct
randomization is enabled.

The second step is to determine the correct size for the
mm_struct slab object from the size of the mm_struct
(excluding the CPU bitmap) and the size the cpumask.

For init_mm we can simply allocate the maximum size this
kernel is compiled for, since we only have one init_mm
in the system, anyway.

Pointer magic by Mike Galbraith, to evade -Wstringop-overflow
getting confused by the dynamically sized array.

Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-team@fb.com
Cc: luto@kernel.org
Link: http://lkml.kernel.org/r/20180716190337.26133-2-riel@surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Drop type and attribute checks in efi_mem_desc_lookup()

The current implementation of efi_mem_desc_lookup() includes the
following check on the memory descriptor it returns:

if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
md->type != EFI_BOOT_SERVICES_DATA &&
md->type != EFI_RUNTIME_SERVICES_DATA) {
continue;
}

This means that only EfiBootServicesData or EfiRuntimeServicesData
regions are considered, or any other region type provided that it
has the EFI_MEMORY_RUNTIME attribute set.

Given what the name of the function implies, and the fact that any
physical address can be described in the UEFI memory map only a single
time, it does not make sense to impose this condition in the body of the
loop, but instead, should be imposed by the caller depending on the value
that is returned to it.

Two such callers exist at the moment:

- The BGRT code when running on x86, via efi_mem_reserve() and
efi_arch_mem_reserve(). In this case, the region is already known to
be EfiBootServicesData, and so the check is redundant.

- The ESRT handling code which introduced this function, which calls it
both directly from efi_esrt_init() and again via efi_mem_reserve() and
efi_arch_mem_reserve() [on x86].

So let's move this check into the callers instead. This preserves the
current behavior both for BGRT and ESRT handling, and allows the lookup
routine to be reused by other [upcoming] users that don't have this
limitation.

In the ESRT case, keep the entire condition, so that platforms that
deviate from the UEFI spec and use something other than
EfiBootServicesData for the ESRT table will keep working as before.

For x86's efi_arch_mem_reserve() implementation, limit the type to
EfiBootServicesData, since it is the only type the reservation code
expects to operate on in the first place.

While we're at it, drop the __init annotation so that drivers can use it
as well.

Tested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180711094040.12506-8-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Use a work queue to invoke EFI Runtime Services

Presently, when a user process requests the kernel to execute any
UEFI runtime service, the kernel temporarily switches to a separate
set of page tables that describe the virtual mapping of the UEFI
runtime services regions in memory. Since UEFI runtime services are
typically invoked with interrupts enabled, any code that may be called
during this time, will have an incorrect view of the process's address
space. Although it is unusual for code running in interrupt context to
make assumptions about the process context it runs in, there are cases
(such as the perf subsystem taking samples) where this causes problems.

So let's set up a work queue for calling UEFI runtime services, so that
the actual calls are made when the work queue items are dispatched by a
work queue worker running in a separate kernel thread. Such threads are
not expected to have userland mappings in the first place, and so the
additional mappings created for the UEFI runtime services can never
clash with any.

The ResetSystem() runtime service is not covered by the work queue
handling, since it is not expected to return, and may be called at a
time when the kernel is torn down to the point where we cannot expect
work queues to still be operational.

The non-blocking variants of SetVariable() and QueryVariableInfo()
are also excluded: these are intended to be used from atomic context,
which obviously rules out waiting for a completion to be signalled by
another thread. Note that these variants are currently only used for
UEFI runtime services calls that occur very early in the boot, and
for ones that occur in critical conditions, e.g., to flush kernel logs
to UEFI variables via efi-pstore.

Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
[ardb: exclude ResetSystem() from the workqueue treatment
merge from 2 separate patches and rewrite commit log]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180711094040.12506-4-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Use efi_mm in x86 as well as ARM

Presently, only ARM uses mm_struct to manage EFI page tables and EFI
runtime region mappings. As this is the preferred approach, let's make
this data structure common across architectures. Specially, for x86,
using this data structure improves code maintainability and readability.

Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
[ardb: don't #include the world to get a declaration of struct mm_struct]
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Lee, Chun-Yi <jlee@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180312084500.10764-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Reorder pr_notice() with add_device_randomness() call

Currently, when we receive a random seed from the EFI stub, we call
add_device_randomness() to incorporate it into the entropy pool, and
issue a pr_notice() saying we are about to do that, e.g.,

[ 0.000000] efi: RNG=0x87ff92cf18
[ 0.000000] random: fast init done
[ 0.000000] efi: seeding entropy pool

Let's reorder those calls to make the output look less confusing:

[ 0.000000] efi: seeding entropy pool
[ 0.000000] efi: RNG=0x87ff92cf18
[ 0.000000] random: fast init done

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180308080020.22828-11-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: call get_event_log before ExitBootServices

With TPM 2.0 specification, the event logs may only be accessible by
calling an EFI Boot Service. Modify the EFI stub to copy the log area to
a new Linux-specific EFI configuration table so it remains accessible
once booted.

When calling this service, it is possible to specify the expected format
of the logs: TPM 1.2 (SHA1) or TPM 2.0 ("Crypto Agile"). For now, only the
first format is retrieved.

Signed-off-by: Thiebaud Weksteen <tweek@google.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

efi: Use PTR_ERR_OR_ZERO()

Fix ptr_ret.cocci warnings:

drivers/firmware/efi/efi.c:610:8-14: WARNING: PTR_ERR_OR_ZERO can be used

Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci

Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arvind Yadav <arvind.yadav.cs@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tyler Baicar <tbaicar@codeaurora.org>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180102181042.19074-4-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Add comment to avoid future expanding of sysfs systab

/sys/firmware/efi/systab shows several different values, it breaks sysfs
one file one value design. But since there are already userspace tools
depend on it eg. kexec-tools so add code comment to alert future expanding
of this file.

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20171206095010.24170-4-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Move some sysfs files to be read-only by root

Thanks to the scripts/leaking_addresses.pl script, it was found that
some EFI values should not be readable by non-root users.

So make them root-only, and to do that, add a __ATTR_RO_MODE() macro to
make this easier, and use it in other places at the same time.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Cc: stable <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20171206095010.24170-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Move efi_mem_type() to common code

This follows efi_mem_attributes(), as it's similarly generic. Drop
__weak from that one though (and don't introduce it for efi_mem_type()
in the first place) to make clear that other overrides to these
functions are really not intended.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170825155019.6740-5-ard.biesheuvel@linaro.org
[ Resolved conflict with: f99afd08a45f: (efi: Update efi_mem_type() to return an error rather than 0) ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi/random: Increase size of firmware supplied randomness

The crng code requires at least 64 bytes (2 * CHACHA20_BLOCK_SIZE)
to complete the fast boot-time init, so provide that many bytes
when invoking UEFI protocols to seed the entropy pool. Also, add
a notice so we can tell from the boot log when the seeding actually
took place.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170825155019.6740-3-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

firmware/efi: Constify attribute_group structures

attribute_group are not supposed to change at runtime. All functions
working with attribute_group provided by <linux/sysfs.h> work with
const attribute_group. So mark the non-const structs as const.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170818194947.19347-14-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Add an EFI table address match function

Add a function that will determine if a supplied physical address matches
the address of an EFI table.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/e1e06441d80f44776df391e0e4cb485b345b7518.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Process the MEMATTR table only if EFI_MEMMAP is enabled

Otherwise e.g. Xen dom0 on x86_64 EFI platforms crashes.

In theory we can check EFI_PARAVIRT too, however,
EFI_MEMMAP looks more targeted and covers more cases.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrew.cooper3@citrix.com
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: linux-efi@vger.kernel.org
Cc: matt@codeblueprint.co.uk
Cc: stable@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1498128697-12943-2-git-send-email-daniel.kiper@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi/esrt: Cleanup bad memory map log messages

The Intel Compute Stick STCK1A8LFC and Weibu F3C platforms both
log 2 error messages during boot:

efi: requested map not found.
esrt: ESRT header is not in the memory map.

Searching the web, this seems to affect many other platforms too.
Since these messages are logged as errors, they appear on-screen during
the boot process even when using the "quiet" boot parameter used by
distros.

Demote the ESRT error to a warning so that it does not appear on-screen,
and delete the error logging from efi_mem_desc_lookup; both callsites
of that function log more specific messages upon failure.

Out of curiosity I looked closer at the Weibu F3C. There is no entry in
the UEFI-provided memory map which corresponds to the ESRT pointer, but
hacking the code to map it anyway, the ESRT does appear to be valid with
2 entries.

Signed-off-by: Daniel Drake <drake@endlessm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Acked-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

efi: Make EFI_MEMORY_ATTRIBUTES_TABLE initialization common across all architectures

Since EFI_PROPERTIES_TABLE and EFI_MEMORY_ATTRIBUTES_TABLE deal with
updating memory region attributes, it makes sense to call
EFI_MEMORY_ATTRIBUTES_TABLE initialization function from the same place
as EFI_PROPERTIES_TABLE. This also moves the EFI_MEMORY_ATTRIBUTES_TABLE
initialization code to a more generic efi initialization path rather
than ARM specific efi initialization. This is important because
EFI_MEMORY_ATTRIBUTES_TABLE will be supported by x86 as well.

Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Lee, Chun-Yi <jlee@suse.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1485868902-20401-4-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Add support for seeding the RNG from a UEFI config table

Specify a Linux specific UEFI configuration table that carries some
random bits, and use the contents during early boot to seed the kernel's
random number generator. This allows much strong random numbers to be
generated early on.

The entropy is fed to the kernel using add_device_randomness(), which is
documented as being appropriate for being called very early.

Since UEFI configuration tables may also be consumed by kexec'd kernels,
register a reboot notifier that updates the seed in the table.

Note that the config table could be generated by the EFI stub or by any
other UEFI driver or application (e.g., GRUB), but the random seed table
GUID and the associated functionality should be considered an internal
kernel interface (unless it is promoted to ABI later on)

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20161112213237.8804-4-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi/efivar_ssdt_load: Don't return success on allocation failure

We should return -ENOMEM here, instead of success.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 475fb4e8b2f4 ("efi / ACPI: load SSTDs from EFI variables")
Link: http://lkml.kernel.org/r/20161018143318.15673-9-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Replace runtime services spinlock with semaphore

The purpose of the efi_runtime_lock is to prevent concurrent calls into
the firmware. There is no need to use spinlocks here, as long as we ensure
that runtime service invocations from an atomic context (i.e., EFI pstore)
cannot block.

So use a semaphore instead, and use down_trylock() in the nonblocking case.
We don't use a mutex here because the mutex_trylock() function must not
be called from interrupt context, whereas the down_trylock() can.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

efi: Allow drivers to reserve boot services forever

Today, it is not possible for drivers to reserve EFI boot services for
access after efi_free_boot_services() has been called on x86. For
ARM/arm64 it can be done simply by calling memblock_reserve().

Having this ability for all three architectures is desirable for a
couple of reasons,

1) It saves drivers copying data out of those regions
2) kexec reboot can now make use of things like ESRT

Instead of using the standard memblock_reserve() which is insufficient
to reserve the region on x86 (see efi_reserve_boot_services()), a new
API is introduced in this patch; efi_mem_reserve().

efi.memmap now always represents which EFI memory regions are
available. On x86 the EFI boot services regions that have not been
reserved via efi_mem_reserve() will be removed from efi.memmap during
efi_free_boot_services().

This has implications for kexec, since it is not possible for a newly
kexec'd kernel to access the same boot services regions that the
initial boot kernel had access to unless they are reserved by every
kexec kernel in the chain.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

efi: Split out EFI memory map functions into new file

Also move the functions from the EFI fake mem driver since future
patches will require access to the memmap insertion code even if
CONFIG_EFI_FAKE_MEM isn't enabled.

This will be useful when we need to build custom EFI memory maps to
allow drivers to mark regions as reserved.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

efi: Add efi_memmap_init_late() for permanent EFI memmap

Drivers need a way to access the EFI memory map at runtime. ARM and
arm64 currently provide this by remapping the EFI memory map into the
vmalloc space before setting up the EFI virtual mappings.

x86 does not provide this functionality which has resulted in the code
in efi_mem_desc_lookup() where it will manually map individual EFI
memmap entries if the memmap has already been torn down on x86,

/*
* If a driver calls this after efi_free_boot_services,
* ->map will be NULL, and the target may also not be mapped.
* So just always get our own virtual map on the CPU.
*
*/
md = early_memremap(p, sizeof (*md));

There isn't a good reason for not providing a permanent EFI memory map
for runtime queries, especially since the EFI regions are not mapped
into the standard kernel page tables.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

efi: Refactor efi_memmap_init_early() into arch-neutral code

Every EFI architecture apart from ia64 needs to setup the EFI memory
map at efi.memmap, and the code for doing that is essentially the same
across all implementations. Therefore, it makes sense to factor this
out into the common code under drivers/firmware/efi/.

The only slight variation is the data structure out of which we pull
the initial memory map information, such as physical address, memory
descriptor size and version, etc. We can address this by passing a
generic data structure (struct efi_memory_map_data) as the argument to
efi_memmap_init_early() which contains the minimum info required for
initialising the memory map.

In the process, this patch also fixes a few undesirable implementation
differences:

- ARM and arm64 were failing to clear the EFI_MEMMAP bit when
unmapping the early EFI memory map. EFI_MEMMAP indicates whether
the EFI memory map is mapped (not the regions contained within) and
can be traversed. It's more correct to set the bit as soon as we
memremap() the passed in EFI memmap.

- Rename efi_unmmap_memmap() to efi_memmap_unmap() to adhere to the
regular naming scheme.

This patch also uses a read-write mapping for the memory map instead
of the read-only mapping currently used on ARM and arm64. x86 needs
the ability to update the memory map in-place when assigning virtual
addresses to regions (efi_map_region()) and tagging regions when
reserving boot services (efi_reserve_boot_services()).

There's no way for the generic fake_mem code to know which mapping to
use without introducing some arch-specific constant/hook, so just use
read-write since read-only is of dubious value for the EFI memory map.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

efi: Fix handling error value in fdt_find_uefi_params

of_get_flat_dt_subnode_by_name can return negative value in case of error.
Assigning the result to unsigned variable and checking if the variable
is lesser than zero is incorrect and always false.
The patch fixes it by using signed variable to check the result.

The problem has been detected using semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Shawn Lin <shawn.lin@rock-chips.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

efi / ACPI: load SSTDs from EFI variables

This patch allows SSDTs to be loaded from EFI variables. It works by
specifying the EFI variable name containing the SSDT to be loaded. All
variables with the same name (regardless of the vendor GUID) will be
loaded.

Note that we can't use acpi_install_table and we must rely on the
dynamic ACPI table loading and bus re-scanning mechanisms. That is
because I2C/SPI controllers are initialized earlier then the EFI
subsystems and all I2C/SPI ACPI devices are enumerated when the
I2C/SPI controllers are initialized.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Xen: EFI: Parse DT parameters for Xen specific UEFI

The EFI DT parameters for bare metal are located under /chosen node,
while for Xen Dom0 they are located under /hyperviosr/uefi node. These
parameters under /chosen and /hyperviosr/uefi are not expected to appear
at the same time.

Parse these EFI parameters and initialize EFI like the way for bare
metal except the runtime services because the runtime services for Xen
Dom0 are available through hypercalls and they are always enabled. So it
sets the EFI_RUNTIME_SERVICES flag if it finds /hyperviosr/uefi node and
bails out in arm_enable_runtime_services() when EFI_RUNTIME_SERVICES
flag is set already.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

efi: Move efi_status_to_err() to drivers/firmware/efi/

Move efi_status_to_err() to the architecture independent code as it's
generally useful in all bits of EFI code where there is a need to
convert an efi_status_t to a kernel error value.

Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kweh Hock Leong <hock.leong.kweh@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: joeyli <jlee@suse.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-27-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi/arm/libstub: Make screen_info accessible to the UEFI stub

In order to hand over the framebuffer described by the GOP protocol and
discovered by the UEFI stub, make struct screen_info accessible by the
stub. This involves allocating a loader data buffer and passing it to the
kernel proper via a UEFI Configuration Table, since the UEFI stub executes
in the context of the decompressor, and cannot access the kernel's copy of
struct screen_info directly.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-22-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Add support for the EFI_MEMORY_ATTRIBUTES_TABLE config table

This declares the GUID and struct typedef for the new memory attributes
table which contains the permissions that can be used to apply stricter
permissions to UEFI Runtime Services memory regions.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-13-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Remove global 'memmap' EFI memory map

Abolish the poorly named EFI memory map, 'memmap'. It is shadowed by a
bunch of local definitions in various files and having two ways to
access the EFI memory map ('efi.memmap' vs. 'memmap') is rather
confusing.

Furthermore, IA64 doesn't even provide this global object, which has
caused issues when trying to write generic EFI memmap code.

Replace all occurrences with efi.memmap, and convert the remaining
iterator code to use for_each_efi_mem_desc().

Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Luck, Tony <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-8-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Iterate over efi.memmap in for_each_efi_memory_desc()

Most of the users of for_each_efi_memory_desc() are equally happy
iterating over the EFI memory map in efi.memmap instead of 'memmap',
since the former is usually a pointer to the latter.

For those users that want to specify an EFI memory map other than
efi.memmap, that can be done using for_each_efi_memory_desc_in_map().
One such example is in the libstub code where the firmware is queried
directly for the memory map, it gets iterated over, and then freed.

This change goes part of the way toward deleting the global 'memmap'
variable, which is not universally available on all architectures
(notably IA64) and is rather poorly named.

Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-7-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Add Persistent Memory type name

Add the "Persistent Memory" string for type 14 introduced in
UEFI 2.5. This is used when printing the UEFI memory map.

old:
efi: mem61: [type=14 | | | | | | | |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)

new:
efi: mem61: [Persistent Memory | | | | | | | |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)

Signed-off-by: Robert Elliott <elliott@hpe.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1454364428-494-14-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Add NV memory attribute

Add the NV memory attribute introduced in UEFI 2.5 and add a
column for it in the types and attributes string used when
printing the UEFI memory map.

old:
efi: mem61: [type=14 | | | | | | | |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)

new:
efi: mem61: [type=14 | | |NV| | | | | |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)

Signed-off-by: Robert Elliott <elliott@hpe.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1454364428-494-13-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Expose non-blocking set_variable() wrapper to efivars

Commit 6d80dba1c9fe ("efi: Provide a non-blocking SetVariable()
operation") implemented a non-blocking alternative for the UEFI
SetVariable() invocation performed by efivars, since it may
occur in atomic context. However, this version of the function
was never exposed via the efivars struct, so the non-blocking
versions was not actually callable. Fix that.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 6d80dba1c9fe ("efi: Provide a non-blocking SetVariable() operation")
Link: http://lkml.kernel.org/r/1454364428-494-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: include asm/early_ioremap.h not asm/efi.h to get early_memremap

The code in efi.c uses early_memremap(), but relies on a transitive
include rather than including asm/early_ioremap.h directly, since
this header did not exist on ia64.

Commit f7d924894265 ("arm64/efi: refactor EFI init and runtime code
for reuse by 32-bit ARM") attempted to work around this by including
asm/efi.h, which transitively includes asm/early_ioremap.h on most
architectures. However, since asm/efi.h does not exist on ia64 either,
this is not much of an improvement.

Now that we have created an asm/early_ioremap.h for ia64, we can just
include it directly.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

x86/efi-bgrt: Fix kernel panic when mapping BGRT data

Starting with this commit 35eb8b81edd4 ("x86/efi: Build our own page
table structures") efi regions have a separate page directory called
"efi_pgd". In order to access any efi region we have to first shift %cr3
to this page table. In the bgrt code we are trying to copy bgrt_header
and image, but these regions fall under "EFI_BOOT_SERVICES_DATA"
and to access these regions we have to shift %cr3 to efi_pgd and not
doing so will cause page fault as shown below.

[ 0.251599] Last level dTLB entries: 4KB 64, 2MB 0, 4MB 0, 1GB 4
[ 0.259126] Freeing SMP alternatives memory: 32K (ffffffff8230e000 - ffffffff82316000)
[ 0.271803] BUG: unable to handle kernel paging request at fffffffefce35002
[ 0.279740] IP: [<ffffffff821bca49>] efi_bgrt_init+0x144/0x1fd
[ 0.286383] PGD 300f067 PUD 0
[ 0.289879] Oops: 0000 [#1] SMP
[ 0.293566] Modules linked in:
[ 0.297039] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.0-rc1-eywa-eywa-built-in-47041+ #2
[ 0.306619] Hardware name: Intel Corporation Skylake Client platform/Skylake Y LPDDR3 RVP3, BIOS SKLSE2R1.R00.B104.B01.1511110114 11/11/2015
[ 0.320925] task: ffffffff820134c0 ti: ffffffff82000000 task.ti: ffffffff82000000
[ 0.329420] RIP: 0010:[<ffffffff821bca49>] [<ffffffff821bca49>] efi_bgrt_init+0x144/0x1fd
[ 0.338821] RSP: 0000:ffffffff82003f18 EFLAGS: 00010246
[ 0.344852] RAX: fffffffefce35000 RBX: fffffffefce35000 RCX: fffffffefce2b000
[ 0.352952] RDX: 000000008a82b000 RSI: ffffffff8235bb80 RDI: 000000008a835000
[ 0.361050] RBP: ffffffff82003f30 R08: 000000008a865000 R09: ffffffffff202850
[ 0.369149] R10: ffffffff811ad62f R11: 0000000000000000 R12: 0000000000000000
[ 0.377248] R13: ffff88016dbaea40 R14: ffffffff822622c0 R15: ffffffff82003fb0
[ 0.385348] FS: 0000000000000000(0000) GS:ffff88016d800000(0000) knlGS:0000000000000000
[ 0.394533] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.401054] CR2: fffffffefce35002 CR3: 000000000300c000 CR4: 00000000003406f0
[ 0.409153] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 0.417252] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 0.425350] Stack:
[ 0.427638] ffffffffffffffff ffffffff82256900 ffff88016dbaea40 ffffffff82003f40
[ 0.436086] ffffffff821bbce0 ffffffff82003f88 ffffffff8219c0c2 0000000000000000
[ 0.444533] ffffffff8219ba4a ffffffff822622c0 0000000000083000 00000000ffffffff
[ 0.452978] Call Trace:
[ 0.455763] [<ffffffff821bbce0>] efi_late_init+0x9/0xb
[ 0.461697] [<ffffffff8219c0c2>] start_kernel+0x463/0x47f
[ 0.467928] [<ffffffff8219ba4a>] ? set_init_arg+0x55/0x55
[ 0.474159] [<ffffffff8219b120>] ? early_idt_handler_array+0x120/0x120
[ 0.481669] [<ffffffff8219b5ee>] x86_64_start_reservations+0x2a/0x2c
[ 0.488982] [<ffffffff8219b72d>] x86_64_start_kernel+0x13d/0x14c
[ 0.495897] Code: 00 41 b4 01 48 8b 78 28 e8 09 36 01 00 48 85 c0 48 89 c3 75 13 48 c7 c7 f8 ac d3 81 31 c0 e8 d7 3b fb fe e9 b5 00 00 00 45 84 e4 <44> 8b 6b 02 74 0d be 06 00 00 00 48 89 df e8 ae 34 0$
[ 0.518151] RIP [<ffffffff821bca49>] efi_bgrt_init+0x144/0x1fd
[ 0.524888] RSP <ffffffff82003f18>
[ 0.528851] CR2: fffffffefce35002
[ 0.532615] ---[ end trace 7b06521e6ebf2aea ]---
[ 0.537852] Kernel panic - not syncing: Attempted to kill the idle task!

As said above one way to fix this bug is to shift %cr3 to efi_pgd but we
are not doing that way because it leaks inner details of how we switch
to EFI page tables into a new call site and it also adds duplicate code.
Instead, we remove the call to efi_lookup_mapped_addr() and always
perform early_mem*() instead of early_io*() because we want to remap RAM
regions and not I/O regions. We also delete efi_lookup_mapped_addr()
because we are no longer using it.

Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Reported-by: Wendy Wang <wendy.wang@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

arm64/efi: refactor EFI init and runtime code for reuse by 32-bit ARM

This refactors the EFI init and runtime code that will be shared
between arm64 and ARM so that it can be built for both archs.

Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

efi: Use correct type for struct efi_memory_map::phys_map

We have been getting away with using a void* for the physical
address of the UEFI memory map, since, even on 32-bit platforms
with 64-bit physical addresses, no truncation takes place if the
memory map has been allocated by the firmware (which only uses
1:1 virtually addressable memory), which is usually the case.

However, commit:

0f96a99dab36 ("efi: Add "efi_fake_mem" boot option")

adds code that clones and modifies the UEFI memory map, and the
clone may live above 4 GB on 32-bit platforms.

This means our use of void* for struct efi_memory_map::phys_map has
graduated from 'incorrect but working' to 'incorrect and
broken', and we need to fix it.

So redefine struct efi_memory_map::phys_map as phys_addr_t, and
get rid of a bunch of casts that are now unneeded.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: izumi.taku@jp.fujitsu.com
Cc: kamezawa.hiroyu@jp.fujitsu.com
Cc: linux-efi@vger.kernel.org
Cc: matt.fleming@intel.com
Link: http://lkml.kernel.org/r/1445593697-1342-1-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Introduce EFI_NX_PE_DATA bit and set it from properties table

UEFI v2.5 introduces a runtime memory protection feature that splits
PE/COFF runtime images into separate code and data regions. Since this
may require special handling by the OS, allocate a EFI_xxx bit to
keep track of whether this feature is currently active or not.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Add support for UEFIv2.5 Properties table

Version 2.5 of the UEFI spec introduces a new configuration table
called the 'EFI Properties table'. Currently, it is only used to
convey whether the Memory Protection feature is enabled, which splits
PE/COFF images into separate code and data memory regions.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Add EFI_MEMORY_MORE_RELIABLE support to efi_md_typeattr_format()

UEFI spec 2.5 introduces new Memory Attribute Definition named
EFI_MEMORY_MORE_RELIABLE. This patch adds this new attribute
support to efi_md_typeattr_format().

Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi/arm64: Clean up efi_get_fdt_params() interface

As we now have a common debug infrastructure between core and arm64 efi,
drop the bit of the interface passing verbose output flags around.

Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi/x86: Move efi=debug option parsing to core

fed6cefe3b6e ("x86/efi: Add a "debug" option to the efi= cmdline")
adds the DBG flag, but does so for x86 only. Move this early param
parsing to core code.

Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Use the generic efi.memmap instead of 'memmap'

Guenter reports that commit:

7bf793115dd9 ("efi, x86: Rearrange efi_mem_attributes()")

breaks the IA64 compilation with the following error:

drivers/built-in.o: In function `efi_mem_attributes': (.text+0xde962): undefined reference to `memmap'

Instead of using the (rather poorly named) global variable
'memmap' which doesn't exist on IA64, use efi.memmap which
points to the 'memmap' object on x86 and arm64 and which is NULL
for IA64.

The fact that efi.memmap is NULL for IA64 is OK because IA64
provides its own implementation of efi_mem_attributes().

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jonathan Zhang <zjzhang@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20151003222607.GA2682@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi, x86: Rearrange efi_mem_attributes()

x86 and ia64 implement efi_mem_attributes() differently. This
function needs to be available for other architectures
(such as arm64) as well, such as for the purpose of ACPI/APEI.

ia64 EFI does not set up a 'memmap' variable and does not set
the EFI_MEMMAP flag, so it needs to have its unique implementation
of efi_mem_attributes().

Move efi_mem_attributes() implementation from x86 to the core
EFI code, and declare it with __weak.

It is recommended that other architectures should not override
the default implementation.

Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Reviewed-by: Matt Fleming <matt.fleming@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438936621-5215-4-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Add support for EFI_MEMORY_RO attribute introduced by UEFIv2.5

The UEFI spec v2.5 introduces a new memory attribute
EFI_MEMORY_RO, which is now the preferred attribute to convey
that the nature of the contents of such a region allows it to be
mapped read-only (i.e., it contains .text and .rodata only).

The specification of the existing EFI_MEMORY_WP attribute has been
updated to align more closely with its common use as a
cacheability attribute rather than a permission attribute.

Add the #define and add the attribute to the memory map dumping
routine.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438936621-5215-1-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi: Check for NULL efi kernel parameters

Even though it is documented how to specifiy efi parameters, it is
possible to cause a kernel panic due to a dereference of a NULL pointer when
parsing such parameters if "efi" alone is given:

PANIC: early exception 0e rip 10:ffffffff812fb361 error 0 cr2 0
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.2.0-rc1+ #450
[ 0.000000] ffffffff81fe20a9 ffffffff81e03d50 ffffffff8184bb0f 00000000000003f8
[ 0.000000] 0000000000000000 ffffffff81e03e08 ffffffff81f371a1 64656c62616e6520
[ 0.000000] 0000000000000069 000000000000005f 0000000000000000 0000000000000000
[ 0.000000] Call Trace:
[ 0.000000] [<ffffffff8184bb0f>] dump_stack+0x45/0x57
[ 0.000000] [<ffffffff81f371a1>] early_idt_handler_common+0x81/0xae
[ 0.000000] [<ffffffff812fb361>] ? parse_option_str+0x11/0x90
[ 0.000000] [<ffffffff81f4dd69>] arch_parse_efi_cmdline+0x15/0x42
[ 0.000000] [<ffffffff81f376e1>] do_early_param+0x50/0x8a
[ 0.000000] [<ffffffff8106b1b3>] parse_args+0x1e3/0x400
[ 0.000000] [<ffffffff81f37a43>] parse_early_options+0x24/0x28
[ 0.000000] [<ffffffff81f37691>] ? loglevel+0x31/0x31
[ 0.000000] [<ffffffff81f37a78>] parse_early_param+0x31/0x3d
[ 0.000000] [<ffffffff81f3ae98>] setup_arch+0x2de/0xc08
[ 0.000000] [<ffffffff8109629a>] ? vprintk_default+0x1a/0x20
[ 0.000000] [<ffffffff81f37b20>] start_kernel+0x90/0x423
[ 0.000000] [<ffffffff81f37495>] x86_64_start_reservations+0x2a/0x2c
[ 0.000000] [<ffffffff81f37582>] x86_64_start_kernel+0xeb/0xef
[ 0.000000] RIP 0xffffffff81ba2efc

This panic is not reproducible with "efi=" as this will result in a non-NULL
zero-length string.

Thus, verify that the pointer to the parameter string is not NULL. This is
consistent with other parameter-parsing functions which check for NULL pointers.

Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

sysfs: Create mountpoints with sysfs_create_mount_point

This allows for better documentation in the code and
it allows for a simpler and fully correct version of
fs_fully_visible to be written.

The mount points converted and their filesystems are:
/sys/hypervisor/s390/ s390_hypfs
/sys/kernel/config/ configfs
/sys/kernel/debug/ debugfs
/sys/firmware/efi/efivars/ efivarfs
/sys/fs/fuse/connections/ fusectl
/sys/fs/pstore/ pstore
/sys/kernel/tracing/ tracefs
/sys/fs/cgroup/ cgroup
/sys/kernel/security/ securityfs
/sys/fs/selinux/ selinuxfs
/sys/fs/smackfs/ smackfs

Cc: stable@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

efi: dmi: List SMBIOS3 table before SMBIOS table

The SMBIOS3 table should appear before the SMBIOS table in
/sys/firmware/efi/systab. This allows user-space utilities which
support both to pick the SMBIOS3 table with a single pass on systems
where both are implemented. The SMBIOS3 entry point is more capable
than the SMBIOS entry point so it should be preferred.

This follows the same logic as the ACPI20 table being listed before
the ACPI table.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Add esrt support

Add sysfs files for the EFI System Resource Table (ESRT) under
/sys/firmware/efi/esrt and for each EFI System Resource Entry under
entries/ as a subdir.

The EFI System Resource Table (ESRT) provides a read-only catalog of
system components for which the system accepts firmware upgrades via
UEFI's "Capsule Update" feature. This module allows userland utilities
to evaluate what firmware updates can be applied to this system, and
potentially arrange for those updates to occur.

The ESRT is described as part of the UEFI specification, in version 2.5
which should be available from http://uefi.org/specifications in early
2015. If you're a member of the UEFI Forum, information about its
addition to the standard is available as UEFI Mantis 1090.

For some hardware platforms, additional restrictions may be found at
http://msdn.microsoft.com/en-us/library/windows/hardware/jj128256.aspx ,
and additional documentation may be found at
http://download.microsoft.com/download/5/F/5/5F5D16CD-2530-4289-8019-94C6A20BED3C/windows-uefi-firmware-update-platform.docx
.

Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Don't look for chosen@0 node on DT platforms

Due to some scary special case handling noticed in drivers/of, various
bits of the ARM* EFI support patches did duplicate looking for @0
variants of various nodes. Unless on an ancient PPC system, these are
not in fact required. Most instances have become refactored out along
the way, this removes the last one.

Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

firmware: efi: Remove unneeded guid unparse

There is no reason to translate guid number to string here.
So remove it in order to not do unneeded work.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Expose underlying UEFI firmware platform size to userland

In some cases (e.g. Intel Bay Trail machines), the kernel will happily
run in 64-bit even if the underlying UEFI firmware platform is
32-bit. That's great, but it's difficult for userland utilities like
grub-install to do the right thing in such a situation.

The kernel already knows about the size of the firmware via
efi_enabled(EFI_64BIT). Add an extra sysfs interface
/sys/firmware/efi/fw_platform_size to expose that information to
userland for low-level utilities to use.

Signed-off-by: Steve McIntyre <steve@einval.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: split off remapping code from efi_config_init()

Split of the remapping code from efi_config_init() so that the caller
can perform its own remapping. This is necessary to correctly handle
virtually remapped UEFI memory regions under kexec, as efi.systab will
have been updated to a virtual address.

Acked-by: Matt Fleming <matt.fleming@intel.com>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

efi: Rename efi_guid_unparse to efi_guid_to_str

Call it what it does - "unparse" is plain-misleading.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>

efi: dmi: add support for SMBIOS 3.0 UEFI configuration table

This adds support to the UEFI side for detecting the presence of
a SMBIOS 3.0 64-bit entry point. This allows the actual SMBIOS
structure table to reside at a physical offset over 4 GB, which
cannot be supported by the legacy SMBIOS 32-bit entry point.

Since the firmware can legally provide both entry points, store
the SMBIOS 3.0 entry point in a separate variable, and let the
DMI decoding layer decide which one will be used.

Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Acked-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

efi: Introduce efi_md_typeattr_format()

At the moment, there are three architectures debug-printing the EFI memory
map at initialization: x86, ia64, and arm64. They all use different format
strings, plus the EFI memory type and the EFI memory attributes are
similarly hard to decode for a human reader.

Introduce a helper __init function that formats the memory type and the
memory attributes in a unified way, to a user-provided character buffer.

The array "memory_type_name" is copied from the arm64 code, temporarily
duplicating it. The (otherwise optional) braces around each string literal
in the initializer list are dropped in order to match the kernel coding
style more closely. The element size is tightened from 32 to 20 bytes
(maximum actual string length + 1) so that we can derive the field width
from the element size.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[ Dropped useless 'register' keyword, which compiler will ignore ]
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Add kernel param efi=noruntime

noefi kernel param means actually disabling efi runtime, Per suggestion
from Leif Lindholm efi=noruntime should be better. But since noefi is
already used in X86 thus just adding another param efi=noruntime for
same purpose.

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Move noefi early param code out of x86 arch code

noefi param can be used for arches other than X86 later, thus move it
out of x86 platform code.

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Autoload efivars

The original patch is from Ben Hutchings's contribution to debian
kernel. Got Ben's permission to remove the code of efi-pstore.c and
send to linux-efi:
https://github.com/BlankOn/linux-debian/blob/master/debian/patches/features/all/efi-autoload-efivars.patch

efivars is generally useful to have on EFI systems, and in some cases
it may be impossible to load it after a kernel upgrade in order to
complete a boot loader update. At the same time we don't want to waste
memory on non-EFI systems by making them built-in.

Instead, give them module aliases as if they are platform drivers, and
register a corresponding platform device whenever EFI runtime services
are available. This should trigger udev to load them.

Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Introduce EFI_PARAVIRT flag

Introduce EFI_PARAVIRT flag. If it is set then kernel runs
on EFI platform but it has not direct control on EFI stuff
like EFI runtime, tables, structures, etc. If not this means
that Linux Kernel has direct access to EFI infrastructure
and everything runs as usual.

This functionality is used in Xen dom0 because hypervisor
has full control on EFI stuff and all calls from dom0 to
EFI must be requested via special hypercall which in turn
executes relevant EFI code in behalf of dom0.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Use early_mem*() instead of early_io*()

Use early_mem*() instead of early_io*() because all mapped EFI regions
are memory (usually RAM but they could also be ROM, EPROM, EEPROM, flash,
etc.) not I/O regions. Additionally, I/O family calls do not work correctly
under Xen in our case. early_ioremap() skips the PFN to MFN conversion
when building the PTE. Using it for memory will attempt to map the wrong
machine frame. However, all artificial EFI structures created under Xen
live in dom0 memory and should be mapped/unmapped using early_mem*() family
calls which map domain memory.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: fdt: Do not report an error during boot if UEFI is not available

Currently, fdt_find_uefi_params() reports an error if no EFI parameters
are found in the DT. This is however a valid case for non-UEFI kernel
booting. This patch checks changes the error reporting to a
pr_info("UEFI not found") when no EFI parameters are found in the DT.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Leif Lindholm <leif.lindholm@linaro.org>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Fix compiler warnings (unused, const, type)

This patch fixes a few compiler warning in the efi code for unused
variable, discarding const qualifier and wrong pointer type:

drivers/firmware/efi/fdt.c|66 col 22| warning: unused variable ‘name’ [-Wunused-variable]
drivers/firmware/efi/efi.c|368 col 3| warning: passing argument 3 of ‘of_get_flat_dt_prop’ from incompatible pointer type [enabled by default]
drivers/firmware/efi/efi.c|368 col 8| warning: assignment discards ‘const’ qualifier from pointer target type [enabled by default]

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: add helper function to get UEFI params from FDT

ARM and ARM64 architectures use the device tree to pass UEFI parameters
from stub to kernel. These parameters are things known to the stub but
not discoverable by the kernel after the stub calls ExitBootSerives().
There is a helper function in:

drivers/firmware/efi/fdt.c

which the stub uses to add the UEFI parameters to the device tree.
This patch adds a complimentary helper function which UEFI runtime
support may use to retrieve the parameters from the device tree.
If an architecture wants to use this helper, it should select
CONFIG_EFI_PARAMS_FROM_FDT.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Use NULL instead of 0 for pointer

Fix following sparse warnings:

drivers/firmware/efi/efivars.c:230:66: warning:
Using plain integer as NULL pointer
drivers/firmware/efi/efi.c:236:27: warning:
Using plain integer as NULL pointer

Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Set feature flags inside feature init functions

It makes more sense to set the feature flag in the success path of the
detection function than it does to rely on the caller doing it. Apart
from it being more logical to group the code and data together, it sets
a much better example for new EFI architectures.

Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Export EFI runtime memory mapping to sysfs

kexec kernel will need exactly same mapping for EFI runtime memory
ranges. Thus here export the runtime ranges mapping to sysfs,
kexec-tools will assemble them and pass to 2nd kernel via setup_data.

Introducing a new directory /sys/firmware/efi/runtime-map just like
/sys/firmware/memmap. Containing below attribute in each file of that
directory:

attribute num_pages phys_addr type virt_addr

Signed-off-by: Dave Young <dyoung@redhat.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: Export more EFI table variables to sysfs

Export fw_vendor, runtime and config table physical addresses to
/sys/firmware/efi/{fw_vendor,runtime,config_table} because kexec kernels
need them.

From EFI spec these 3 variables will be updated to virtual address after
entering virtual mode. But kernel startup code will need the physical
address.

Signed-off-by: Dave Young <dyoung@redhat.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: x86: make efi_lookup_mapped_addr() a common function

efi_lookup_mapped_addr() is a handy utility for other platforms than
x86. Move it from arch/x86 to drivers/firmware. Add memmap pointer
to global efi structure, and initialise it on x86.

Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: x86: ia64: provide a generic efi_config_init()

Common to (U)EFI support on all platforms is the global "efi" data
structure, and the code that parses the System Table to locate
addresses to populate that structure with.

This patch adds both of these to the global EFI driver code and
removes the local definition of the global "efi" data structure from
the x86 and ia64 code.

Squashed into one big patch to avoid breaking bisection.

Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi: split efisubsystem from efivars

This registers /sys/firmware/efi/{,systab,efivars/} whenever EFI is enabled
and the system is booted with EFI.

This allows
*) userspace to check for the existence of /sys/firmware/efi as a way
to determine whether or it is running on an EFI system.
*) 'mount -t efivarfs none /sys/firmware/efi/efivars' without manually
loading any modules.

[ Also, move the efivar API into vars.c and unconditionally compile it.
This allows us to move efivars.c, which now only contains the sysfs
variable code, into the firmware/efi directory. Note that the efivars.c
filename is kept to maintain backwards compatability with the old
efivars.ko module. With this patch it is now possible for efivarfs
to be built without CONFIG_EFI_VARS - Matt ]

Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Mike Waychison <mikew@google.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Chun-Yi Lee <jlee@suse.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Tobias Powalowski <tpowa@archlinux.org>
Signed-off-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>