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path: root/drivers/firmware/efi/memattr.c
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2023-02-23Merge tag 'efi-next-for-v6.3' of ↵Linus Torvalds
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 ...
2023-02-04efi: Discover BTI support in runtime services regionsArd Biesheuvel
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>
2023-02-02efi: Accept version 2 of memory attributes tableArd Biesheuvel
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>
2021-05-22efi: Allow EFI_MEMORY_XP and EFI_MEMORY_RO both to be clearedHeiner Kallweit
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: 10f0d2f577053 ("efi: Implement generic support for the Memory Attributes table") Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi: Move mem_attr_table out of struct efiArd Biesheuvel
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>
2019-02-04efi: Replace GPL license boilerplate with SPDX headersArd Biesheuvel
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>
2019-02-04efi/memattr: Don't bail on zero VA if it equals the region's PAArd Biesheuvel
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: 10f0d2f577053 ("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>
2017-02-01x86/efi: Add support for EFI_MEMORY_ATTRIBUTES_TABLESai Praneeth
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>
2017-02-01efi: Introduce the EFI_MEM_ATTR bit and set it from the memory attributes tableSai Praneeth
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>
2016-04-28efi: Implement generic support for the Memory Attributes tableArd Biesheuvel
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>