Commit graph

10 commits

Author SHA1 Message Date
Linus Torvalds
06e1a81c48 A healthy mix of EFI contributions this time:
- Performance tweaks for efifb earlycon by Andy
 
 - Preparatory refactoring and cleanup work in the efivar layer by Johan,
   which is needed to accommodate the Snapdragon arm64 laptops that
   expose their EFI variable store via a TEE secure world API.
 
 - Enhancements to the EFI memory map handling so that Xen dom0 can
   safely access EFI configuration tables (Demi Marie)
 
 - Wire up the newly introduced IBT/BTI flag in the EFI memory attributes
   table, so that firmware that is generated with ENDBR/BTI landing pads
   will be mapped with enforcement enabled.
 
 - Clean up how we check and print the EFI revision exposed by the
   firmware.
 
 - Incorporate EFI memory attributes protocol definition contributed by
   Evgeniy and wire it up in the EFI zboot code. This ensures that these
   images can execute under new and stricter rules regarding the default
   memory permissions for EFI page allocations. (More work is in progress
   here)
 
 - CPER header cleanup by Dan Williams
 
 - Use a raw spinlock to protect the EFI runtime services stack on arm64
   to ensure the correct semantics under -rt. (Pierre)
 
 - EFI framebuffer quirk for Lenovo Ideapad by Darrell.
 -----BEGIN PGP SIGNATURE-----
 
 iQGzBAABCgAdFiEE+9lifEBpyUIVN1cpw08iOZLZjyQFAmPzuwsACgkQw08iOZLZ
 jyS7dwwAm95DlDxFIQi4FmTm2mqJws9PyDrkfaAK1CoyqCgeOLQT2FkVolgr8jne
 pwpwCTXtYP8y0BZvdQEIjpAq/BHKaD3GJSPfl7lo+pnUu68PpsFWaV6EdT33KKfj
 QeF0MnUvrqUeTFI77D+S0ZW2zxdo9eCcahF3TPA52/bEiiDHWBF8Qm9VHeQGklik
 zoXA15ft3mgITybgjEA0ncGrVZiBMZrYoMvbdkeoedfw02GN/eaQn8d2iHBtTDEh
 3XNlo7ONX0v50cjt0yvwFEA0AKo0o7R1cj+ziKH/bc4KjzIiCbINhy7blroSq+5K
 YMlnPHuj8Nhv3I+MBdmn/nxRCQeQsE4RfRru04hfNfdcqjAuqwcBvRXvVnjWKZHl
 CmUYs+p/oqxrQ4BjiHfw0JKbXRsgbFI6o3FeeLH9kzI9IDUPpqu3Ma814FVok9Ai
 zbOCrJf5tEtg5tIavcUESEMBuHjEafqzh8c7j7AAqbaNjlihsqosDy9aYoarEi5M
 f/tLec86
 =+pOz
 -----END PGP SIGNATURE-----

Merge tag 'efi-next-for-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:
 "A healthy mix of EFI contributions this time:

   - Performance tweaks for efifb earlycon (Andy)

   - Preparatory refactoring and cleanup work in the efivar layer, which
     is needed to accommodate the Snapdragon arm64 laptops that expose
     their EFI variable store via a TEE secure world API (Johan)

   - Enhancements to the EFI memory map handling so that Xen dom0 can
     safely access EFI configuration tables (Demi Marie)

   - Wire up the newly introduced IBT/BTI flag in the EFI memory
     attributes table, so that firmware that is generated with ENDBR/BTI
     landing pads will be mapped with enforcement enabled

   - Clean up how we check and print the EFI revision exposed by the
     firmware

   - Incorporate EFI memory attributes protocol definition and wire it
     up in the EFI zboot code (Evgeniy)

     This ensures that these images can execute under new and stricter
     rules regarding the default memory permissions for EFI page
     allocations (More work is in progress here)

   - CPER header cleanup (Dan Williams)

   - Use a raw spinlock to protect the EFI runtime services stack on
     arm64 to ensure the correct semantics under -rt (Pierre)

   - EFI framebuffer quirk for Lenovo Ideapad (Darrell)"

* tag 'efi-next-for-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits)
  firmware/efi sysfb_efi: Add quirk for Lenovo IdeaPad Duet 3
  arm64: efi: Make efi_rt_lock a raw_spinlock
  efi: Add mixed-mode thunk recipe for GetMemoryAttributes
  efi: x86: Wire up IBT annotation in memory attributes table
  efi: arm64: Wire up BTI annotation in memory attributes table
  efi: Discover BTI support in runtime services regions
  efi/cper, cxl: Remove cxl_err.h
  efi: Use standard format for printing the EFI revision
  efi: Drop minimum EFI version check at boot
  efi: zboot: Use EFI protocol to remap code/data with the right attributes
  efi/libstub: Add memory attribute protocol definitions
  efi: efivars: prevent double registration
  efi: verify that variable services are supported
  efivarfs: always register filesystem
  efi: efivars: add efivars printk prefix
  efi: Warn if trying to reserve memory under Xen
  efi: Actually enable the ESRT under Xen
  efi: Apply allowlist to EFI configuration tables when running under Xen
  efi: xen: Implement memory descriptor lookup based on hypercall
  efi: memmap: Disregard bogus entries instead of returning them
  ...
2023-02-23 14:41:48 -08:00
Ard Biesheuvel
cf1d2ffcc6 efi: Discover BTI support in runtime services regions
Add the generic plumbing to detect whether or not the runtime code
regions were constructed with BTI/IBT landing pads by the firmware,
permitting the OS to enable enforcement when mapping these regions into
the OS's address space.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
2023-02-04 09:19:02 +01:00
Ard Biesheuvel
636ab417a7 efi: Accept version 2 of memory attributes table
UEFI v2.10 introduces version 2 of the memory attributes table, which
turns the reserved field into a flags field, but is compatible with
version 1 in all other respects. So let's not complain about version 2
if we encounter it.

Cc: <stable@vger.kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-02-02 18:32:25 +01:00
Heiner Kallweit
45add3cc99 efi: Allow EFI_MEMORY_XP and EFI_MEMORY_RO both to be cleared
UEFI spec 2.9, p.108, table 4-1 lists the scenario that both attributes
are cleared with the description "No memory access protection is
possible for Entry". So we can have valid entries where both attributes
are cleared, so remove the check.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Fixes: 10f0d2f577 ("efi: Implement generic support for the Memory Attributes table")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-05-22 14:05:13 +02:00
Ard Biesheuvel
a17e809ea5 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>
2020-02-23 21:59:42 +01:00
Ard Biesheuvel
4febfb8dd0 efi: Replace GPL license boilerplate with SPDX headers
Replace all GPL license blurbs with an equivalent SPDX header (most
files are GPLv2, some are GPLv2+). While at it, drop some outdated
header changelogs as well.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Alexander Graf <agraf@suse.de>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Jeffrey Hugo <jhugo@codeaurora.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
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: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190202094119.13230-7-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-04 08:27:25 +01:00
Ard Biesheuvel
5de0fef023 efi/memattr: Don't bail on zero VA if it equals the region's PA
The EFI memory attributes code cross-references the EFI memory map with
the more granular EFI memory attributes table to ensure that they are in
sync before applying the strict permissions to the regions it describes.

Since we always install virtual mappings for the EFI runtime regions to
which these strict permissions apply, we currently perform a sanity check
on the EFI memory descriptor, and ensure that the EFI_MEMORY_RUNTIME bit
is set, and that the virtual address has been assigned.

However, in cases where a runtime region exists at physical address 0x0,
and the virtual mapping equals the physical mapping, e.g., when running
in mixed mode on x86, we encounter a memory descriptor with the runtime
attribute and virtual address 0x0, and incorrectly draw the conclusion
that a runtime region exists for which no virtual mapping was installed,
and give up altogether. The consequence of this is that firmware mappings
retain their read-write-execute permissions, making the system more
vulnerable to attacks.

So let's only bail if the virtual address of 0x0 has been assigned to a
physical region that does not reside at address 0x0.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Alexander Graf <agraf@suse.de>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Jeffrey Hugo <jhugo@codeaurora.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 10f0d2f577 ("efi: Implement generic support for the Memory ...")
Link: http://lkml.kernel.org/r/20190202094119.13230-4-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-04 08:26:34 +01:00
Sai Praneeth
18141e89a7 x86/efi: Add support for EFI_MEMORY_ATTRIBUTES_TABLE
UEFI v2.6 introduces EFI_MEMORY_ATTRIBUTES_TABLE which describes memory
protections that may be applied to the EFI Runtime code and data regions by
the kernel. This enables the kernel to map these regions more strictly thereby
increasing security.

Presently, the only valid bits for the attribute field of a memory descriptor
are EFI_MEMORY_RO and EFI_MEMORY_XP, hence use these bits to update the
mappings in efi_pgd.

The UEFI specification recommends to use this feature instead of
EFI_PROPERTIES_TABLE and hence while updating EFI mappings we first
check for EFI_MEMORY_ATTRIBUTES_TABLE and if it's present we update
the mappings according to this table and hence disregarding
EFI_PROPERTIES_TABLE even if it's published by the firmware. We consider
EFI_PROPERTIES_TABLE only when EFI_MEMORY_ATTRIBUTES_TABLE is absent.

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>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Lee, Chun-Yi <jlee@suse.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/1485868902-20401-6-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-01 08:45:44 +01:00
Sai Praneeth
a19ebf59e2 efi: Introduce the EFI_MEM_ATTR bit and set it from the memory attributes table
UEFI v2.6 introduces a configuration table called
EFI_MEMORY_ATTRIBUTES_TABLE which provides additional information about
EFI runtime regions. Currently this table describes memory protections
that may be applied to the EFI Runtime code and data regions by the kernel.

Allocate a EFI_XXX bit to keep track of whether this feature is
published by firmware or not.

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/1485868902-20401-5-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-01 08:45:44 +01:00
Ard Biesheuvel
10f0d2f577 efi: Implement generic support for the Memory Attributes table
This implements shared support for discovering the presence of the
Memory Attributes table, and for parsing and validating its contents.

The table is validated against the construction rules in the UEFI spec.
Since this is a new table, it makes sense to complain if we encounter
a table that does not follow those rules.

The parsing and validation routine takes a callback that can be specified
per architecture, that gets passed each unique validated region, with the
virtual address retrieved from the ordinary memory map.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[ Trim pr_*() strings to 80 cols and use EFI consistently. ]
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/1461614832-17633-14-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28 11:33:54 +02:00