466 Commits

Author SHA1 Message Date
Ard Biesheuvel
0b1d9debe3 efi/libstub: randomalloc: Return EFI_OUT_OF_RESOURCES on failure
The logic in efi_random_alloc() will iterate over the memory map twice,
once to count the number of candidate slots, and another time to locate
the chosen slot after randomization.

If there is insufficient memory to do the allocation, the second loop
will run to completion without actually having located a slot, but we
currently return EFI_SUCCESS in this case, as we fail to initialize
status to the appropriate error value of EFI_OUT_OF_RESOURCES.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-03-23 15:15:45 +01:00
Ard Biesheuvel
fc3608aaa5 efi/libstub: Use relocated version of kernel's struct screen_info
In some cases, we expose the kernel's struct screen_info to the EFI stub
directly, so it gets populated before even entering the kernel.  This
means the early console is available as soon as the early param parsing
happens, which is nice. It also means we need two different ways to pass
this information, as this trick only works if the EFI stub is baked into
the core kernel image, which is not always the case.

Huacai reports that the preparatory refactoring that was needed to
implement this alternative method for zboot resulted in a non-functional
efifb earlycon for other cases as well, due to the reordering of the
kernel image relocation with the population of the screen_info struct,
and the latter now takes place after copying the image to its new
location, which means we copy the old, uninitialized state.

So let's ensure that the same-image version of alloc_screen_info()
produces the correct screen_info pointer, by taking the displacement of
the loaded image into account.

Reported-by: Huacai Chen <chenhuacai@loongson.cn>
Tested-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://lore.kernel.org/linux-efi/20230310021749.921041-1-chenhuacai@loongson.cn/
Fixes: 42c8ea3dca094ab8 ("efi: libstub: Factor out EFI stub entrypoint into separate file")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-03-23 12:27:18 +01:00
Ard Biesheuvel
97fd768e50 efi/libstub: zboot: Add compressed image to make targets
Avoid needlessly rebuilding the compressed image by adding the file
'vmlinuz' to the 'targets' Kbuild make variable.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-03-21 15:20:56 +01:00
Ard Biesheuvel
f59a7ec1e6 efi/libstub: smbios: Drop unused 'recsize' parameter
We no longer use the recsize argument for locating the string table in
an SMBIOS record, so we can drop it from the internal API.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-03-18 11:44:57 +01:00
Ard Biesheuvel
eb684408f3 arm64: efi: Use SMBIOS processor version to key off Ampere quirk
Instead of using the SMBIOS type 1 record 'family' field, which is often
modified by OEMs, use the type 4 'processor ID' and 'processor version'
fields, which are set to a small set of probe-able values on all known
Ampere EFI systems in the field.

Fixes: 550b33cfd4452968 ("arm64: efi: Force the use of ...")
Tested-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-03-18 11:44:56 +01:00
Ard Biesheuvel
34343eb06a efi/libstub: smbios: Use length member instead of record struct size
The type 1 SMBIOS record happens to always be the same size, but there
are other record types which have been augmented over time, and so we
should really use the length field in the header to decide where the
string table starts.

Fixes: 550b33cfd4452968 ("arm64: efi: Force the use of ...")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-03-18 11:37:56 +01:00
Ard Biesheuvel
3c60f67b4b efi/libstub: arm64: Remap relocated image with strict permissions
After relocating the executable image, use the EFI memory attributes
protocol to remap the code and data regions with the appropriate
permissions.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-03-10 14:11:39 +01:00
Ard Biesheuvel
c7d9e628b8 efi/libstub: zboot: Mark zboot EFI application as NX compatible
Now that the zboot loader will invoke the EFI memory attributes protocol
to remap the decompressed code and rodata as read-only/executable, we
can set the PE/COFF header flag that indicates to the firmware that the
application does not rely on writable memory being executable at the
same time.

Cc: <stable@vger.kernel.org> # v6.2+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-03-10 14:11:39 +01:00
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.
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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
Linus Torvalds
8bf1a529cd arm64 updates for 6.3:
- Support for arm64 SME 2 and 2.1. SME2 introduces a new 512-bit
   architectural register (ZT0, for the look-up table feature) that Linux
   needs to save/restore.
 
 - Include TPIDR2 in the signal context and add the corresponding
   kselftests.
 
 - Perf updates: Arm SPEv1.2 support, HiSilicon uncore PMU updates, ACPI
   support to the Marvell DDR and TAD PMU drivers, reset DTM_PMU_CONFIG
   (ARM CMN) at probe time.
 
 - Support for DYNAMIC_FTRACE_WITH_CALL_OPS on arm64.
 
 - Permit EFI boot with MMU and caches on. Instead of cleaning the entire
   loaded kernel image to the PoC and disabling the MMU and caches before
   branching to the kernel bare metal entry point, leave the MMU and
   caches enabled and rely on EFI's cacheable 1:1 mapping of all of
   system RAM to populate the initial page tables.
 
 - Expose the AArch32 (compat) ELF_HWCAP features to user in an arm64
   kernel (the arm32 kernel only defines the values).
 
 - Harden the arm64 shadow call stack pointer handling: stash the shadow
   stack pointer in the task struct on interrupt, load it directly from
   this structure.
 
 - Signal handling cleanups to remove redundant validation of size
   information and avoid reading the same data from userspace twice.
 
 - Refactor the hwcap macros to make use of the automatically generated
   ID registers. It should make new hwcaps writing less error prone.
 
 - Further arm64 sysreg conversion and some fixes.
 
 - arm64 kselftest fixes and improvements.
 
 - Pointer authentication cleanups: don't sign leaf functions, unify
   asm-arch manipulation.
 
 - Pseudo-NMI code generation optimisations.
 
 - Minor fixes for SME and TPIDR2 handling.
 
 - Miscellaneous updates: ARCH_FORCE_MAX_ORDER is now selectable, replace
   strtobool() to kstrtobool() in the cpufeature.c code, apply dynamic
   shadow call stack in two passes, intercept pfn changes in set_pte_at()
   without the required break-before-make sequence, attempt to dump all
   instructions on unhandled kernel faults.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - Support for arm64 SME 2 and 2.1. SME2 introduces a new 512-bit
   architectural register (ZT0, for the look-up table feature) that
   Linux needs to save/restore

 - Include TPIDR2 in the signal context and add the corresponding
   kselftests

 - Perf updates: Arm SPEv1.2 support, HiSilicon uncore PMU updates, ACPI
   support to the Marvell DDR and TAD PMU drivers, reset DTM_PMU_CONFIG
   (ARM CMN) at probe time

 - Support for DYNAMIC_FTRACE_WITH_CALL_OPS on arm64

 - Permit EFI boot with MMU and caches on. Instead of cleaning the
   entire loaded kernel image to the PoC and disabling the MMU and
   caches before branching to the kernel bare metal entry point, leave
   the MMU and caches enabled and rely on EFI's cacheable 1:1 mapping of
   all of system RAM to populate the initial page tables

 - Expose the AArch32 (compat) ELF_HWCAP features to user in an arm64
   kernel (the arm32 kernel only defines the values)

 - Harden the arm64 shadow call stack pointer handling: stash the shadow
   stack pointer in the task struct on interrupt, load it directly from
   this structure

 - Signal handling cleanups to remove redundant validation of size
   information and avoid reading the same data from userspace twice

 - Refactor the hwcap macros to make use of the automatically generated
   ID registers. It should make new hwcaps writing less error prone

 - Further arm64 sysreg conversion and some fixes

 - arm64 kselftest fixes and improvements

 - Pointer authentication cleanups: don't sign leaf functions, unify
   asm-arch manipulation

 - Pseudo-NMI code generation optimisations

 - Minor fixes for SME and TPIDR2 handling

 - Miscellaneous updates: ARCH_FORCE_MAX_ORDER is now selectable,
   replace strtobool() to kstrtobool() in the cpufeature.c code, apply
   dynamic shadow call stack in two passes, intercept pfn changes in
   set_pte_at() without the required break-before-make sequence, attempt
   to dump all instructions on unhandled kernel faults

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (130 commits)
  arm64: fix .idmap.text assertion for large kernels
  kselftest/arm64: Don't require FA64 for streaming SVE+ZA tests
  kselftest/arm64: Copy whole EXTRA context
  arm64: kprobes: Drop ID map text from kprobes blacklist
  perf: arm_spe: Print the version of SPE detected
  perf: arm_spe: Add support for SPEv1.2 inverted event filtering
  perf: Add perf_event_attr::config3
  arm64/sme: Fix __finalise_el2 SMEver check
  drivers/perf: fsl_imx8_ddr_perf: Remove set-but-not-used variable
  arm64/signal: Only read new data when parsing the ZT context
  arm64/signal: Only read new data when parsing the ZA context
  arm64/signal: Only read new data when parsing the SVE context
  arm64/signal: Avoid rereading context frame sizes
  arm64/signal: Make interface for restore_fpsimd_context() consistent
  arm64/signal: Remove redundant size validation from parse_user_sigframe()
  arm64/signal: Don't redundantly verify FPSIMD magic
  arm64/cpufeature: Use helper macros to specify hwcaps
  arm64/cpufeature: Always use symbolic name for feature value in hwcaps
  arm64/sysreg: Initial unsigned annotations for ID registers
  arm64/sysreg: Initial annotation of signed ID registers
  ...
2023-02-21 15:27:48 -08:00
Darren Hart
190233164c arm64: efi: Force the use of SetVirtualAddressMap() on eMAG and Altra Max machines
Commit 550b33cfd445 ("arm64: efi: Force the use of SetVirtualAddressMap()
on Altra machines") identifies the Altra family via the family field in
the type#1 SMBIOS record. eMAG and Altra Max machines are similarly
affected but not detected with the strict strcmp test.

The type1_family smbios string is not an entirely reliable means of
identifying systems with this issue as OEMs can, and do, use their own
strings for these fields. However, until we have a better solution,
capture the bulk of these systems by adding strcmp matching for "eMAG"
and "Altra Max".

Fixes: 550b33cfd445 ("arm64: efi: Force the use of SetVirtualAddressMap() on Altra machines")
Cc: <stable@vger.kernel.org> # 6.1.x
Cc: Alexandru Elisei <alexandru.elisei@gmail.com>
Signed-off-by: Darren Hart <darren@os.amperecomputing.com>
Tested-by: Justin He <justin.he@arm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-02-09 12:38:35 +01:00
Ard Biesheuvel
ace013a543 efi: zboot: Use EFI protocol to remap code/data with the right attributes
Use the recently introduced EFI_MEMORY_ATTRIBUTES_PROTOCOL in the zboot
implementation to set the right attributes for the code and data
sections of the decompressed image, i.e., EFI_MEMORY_RO for code and
EFI_MEMORY_XP for data.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-02-03 16:39:22 +01:00
Evgeniy Baskov
79729f26b0 efi/libstub: Add memory attribute protocol definitions
EFI_MEMORY_ATTRIBUTE_PROTOCOL servers as a better alternative to
DXE services for setting memory attributes in EFI Boot Services
environment. This protocol is better since it is a part of UEFI
specification itself and not UEFI PI specification like DXE
services.

Add EFI_MEMORY_ATTRIBUTE_PROTOCOL definitions.
Support mixed mode properly for its calls.

Tested-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Evgeniy Baskov <baskov@ispras.ru>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-30 13:11:34 +01:00
Ard Biesheuvel
6178617038 efi: arm64: enter with MMU and caches enabled
Instead of cleaning the entire loaded kernel image to the PoC and
disabling the MMU and caches before branching to the kernel's bare metal
entry point, we can leave the MMU and caches enabled, and rely on EFI's
cacheable 1:1 mapping of all of system RAM (which is mandated by the
spec) to populate the initial page tables.

This removes the need for managing coherency in software, which is
tedious and error prone.

Note that we still need to clean the executable region of the image to
the PoU if this is required for I/D coherency, but only if we actually
decided to move the image in memory, as otherwise, this will have been
taken care of by the loader.

This change affects both the builtin EFI stub as well as the zboot
decompressor, which now carries the entire EFI stub along with the
decompression code and the compressed image.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20230111102236.1430401-7-ardb@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-01-24 11:51:08 +00:00
Linus Torvalds
4eb77fa102 - Do some spring cleaning to the compressed boot code by moving the
EFI mixed-mode code to a separate compilation unit, the AMD memory
 encryption early code where it belongs and fixing up build dependencies.
 Make the deprecated EFI handover protocol optional with the goal of
 removing it at some point (Ard Biesheuvel)
 
 - Skip realmode init code on Xen PV guests as it is not needed there
 
 - Remove an old 32-bit PIC code compiler workaround
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Merge tag 'x86_boot_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 boot updates from Borislav Petkov:
 "A  of early boot cleanups and fixes.

   - Do some spring cleaning to the compressed boot code by moving the
     EFI mixed-mode code to a separate compilation unit, the AMD memory
     encryption early code where it belongs and fixing up build
     dependencies. Make the deprecated EFI handover protocol optional
     with the goal of removing it at some point (Ard Biesheuvel)

   - Skip realmode init code on Xen PV guests as it is not needed there

   - Remove an old 32-bit PIC code compiler workaround"

* tag 'x86_boot_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Remove x86_32 PIC using %ebx workaround
  x86/boot: Skip realmode init code when running as Xen PV guest
  x86/efi: Make the deprecated EFI handover protocol optional
  x86/boot/compressed: Only build mem_encrypt.S if AMD_MEM_ENCRYPT=y
  x86/boot/compressed: Adhere to calling convention in get_sev_encryption_bit()
  x86/boot/compressed: Move startup32_check_sev_cbit() out of head_64.S
  x86/boot/compressed: Move startup32_check_sev_cbit() into .text
  x86/boot/compressed: Move startup32_load_idt() out of head_64.S
  x86/boot/compressed: Move startup32_load_idt() into .text section
  x86/boot/compressed: Pull global variable reference into startup32_load_idt()
  x86/boot/compressed: Avoid touching ECX in startup32_set_idt_entry()
  x86/boot/compressed: Simplify IDT/GDT preserve/restore in the EFI thunk
  x86/boot/compressed, efi: Merge multiple definitions of image_offset into one
  x86/boot/compressed: Move efi32_pe_entry() out of head_64.S
  x86/boot/compressed: Move efi32_entry out of head_64.S
  x86/boot/compressed: Move efi32_pe_entry into .text section
  x86/boot/compressed: Move bootargs parsing out of 32-bit startup code
  x86/boot/compressed: Move 32-bit entrypoint code into .text section
  x86/boot/compressed: Rename efi_thunk_64.S to efi-mixed.S
2022-12-13 14:45:29 -08:00
Linus Torvalds
fc4c9f4504 EFI updates for v6.2:
- Refactor the zboot code so that it incorporates all the EFI stub
   logic, rather than calling the decompressed kernel as a EFI app.
 - Add support for initrd= command line option to x86 mixed mode.
 - Allow initrd= to be used with arbitrary EFI accessible file systems
   instead of just the one the kernel itself was loaded from.
 - Move some x86-only handling and manipulation of the EFI memory map
   into arch/x86, as it is not used anywhere else.
 - More flexible handling of any random seeds provided by the boot
   environment (i.e., systemd-boot) so that it becomes available much
   earlier during the boot.
 - Allow improved arch-agnostic EFI support in loaders, by setting a
   uniform baseline of supported features, and adding a generic magic
   number to the DOS/PE header. This should allow loaders such as GRUB or
   systemd-boot to reduce the amount of arch-specific handling
   substantially.
 - (arm64) Run EFI runtime services from a dedicated stack, and use it to
   recover from synchronous exceptions that might occur in the firmware
   code.
 - (arm64) Ensure that we don't allocate memory outside of the 48-bit
   addressable physical range.
 - Make EFI pstore record size configurable
 - Add support for decoding CXL specific CPER records
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Merge tag 'efi-next-for-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:
 "Another fairly sizable pull request, by EFI subsystem standards.

  Most of the work was done by me, some of it in collaboration with the
  distro and bootloader folks (GRUB, systemd-boot), where the main focus
  has been on removing pointless per-arch differences in the way EFI
  boots a Linux kernel.

   - Refactor the zboot code so that it incorporates all the EFI stub
     logic, rather than calling the decompressed kernel as a EFI app.

   - Add support for initrd= command line option to x86 mixed mode.

   - Allow initrd= to be used with arbitrary EFI accessible file systems
     instead of just the one the kernel itself was loaded from.

   - Move some x86-only handling and manipulation of the EFI memory map
     into arch/x86, as it is not used anywhere else.

   - More flexible handling of any random seeds provided by the boot
     environment (i.e., systemd-boot) so that it becomes available much
     earlier during the boot.

   - Allow improved arch-agnostic EFI support in loaders, by setting a
     uniform baseline of supported features, and adding a generic magic
     number to the DOS/PE header. This should allow loaders such as GRUB
     or systemd-boot to reduce the amount of arch-specific handling
     substantially.

   - (arm64) Run EFI runtime services from a dedicated stack, and use it
     to recover from synchronous exceptions that might occur in the
     firmware code.

   - (arm64) Ensure that we don't allocate memory outside of the 48-bit
     addressable physical range.

   - Make EFI pstore record size configurable

   - Add support for decoding CXL specific CPER records"

* tag 'efi-next-for-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (43 commits)
  arm64: efi: Recover from synchronous exceptions occurring in firmware
  arm64: efi: Execute runtime services from a dedicated stack
  arm64: efi: Limit allocations to 48-bit addressable physical region
  efi: Put Linux specific magic number in the DOS header
  efi: libstub: Always enable initrd command line loader and bump version
  efi: stub: use random seed from EFI variable
  efi: vars: prohibit reading random seed variables
  efi: random: combine bootloader provided RNG seed with RNG protocol output
  efi/cper, cxl: Decode CXL Error Log
  efi/cper, cxl: Decode CXL Protocol Error Section
  efi: libstub: fix efi_load_initrd_dev_path() kernel-doc comment
  efi: x86: Move EFI runtime map sysfs code to arch/x86
  efi: runtime-maps: Clarify purpose and enable by default for kexec
  efi: pstore: Add module parameter for setting the record size
  efi: xen: Set EFI_PARAVIRT for Xen dom0 boot on all architectures
  efi: memmap: Move manipulation routines into x86 arch tree
  efi: memmap: Move EFI fake memmap support into x86 arch tree
  efi: libstub: Undeprecate the command line initrd loader
  efi: libstub: Add mixed mode support to command line initrd loader
  efi: libstub: Permit mixed mode return types other than efi_status_t
  ...
2022-12-13 14:31:47 -08:00
Linus Torvalds
06cff4a58e arm64 updates for 6.2
ACPI:
 	* Enable FPDT support for boot-time profiling
 	* Fix CPU PMU probing to work better with PREEMPT_RT
 	* Update SMMUv3 MSI DeviceID parsing to latest IORT spec
 	* APMT support for probing Arm CoreSight PMU devices
 
 CPU features:
 	* Advertise new SVE instructions (v2.1)
 	* Advertise range prefetch instruction
 	* Advertise CSSC ("Common Short Sequence Compression") scalar
 	  instructions, adding things like min, max, abs, popcount
 	* Enable DIT (Data Independent Timing) when running in the kernel
 	* More conversion of system register fields over to the generated
 	  header
 
 CPU misfeatures:
 	* Workaround for Cortex-A715 erratum #2645198
 
 Dynamic SCS:
 	* Support for dynamic shadow call stacks to allow switching at
 	  runtime between Clang's SCS implementation and the CPU's
 	  pointer authentication feature when it is supported (complete
 	  with scary DWARF parser!)
 
 Tracing and debug:
 	* Remove static ftrace in favour of, err, dynamic ftrace!
 	* Seperate 'struct ftrace_regs' from 'struct pt_regs' in core
 	  ftrace and existing arch code
 	* Introduce and implement FTRACE_WITH_ARGS on arm64 to replace
 	  the old FTRACE_WITH_REGS
 	* Extend 'crashkernel=' parameter with default value and fallback
 	  to placement above 4G physical if initial (low) allocation
 	  fails
 
 SVE:
 	* Optimisation to avoid disabling SVE unconditionally on syscall
 	  entry and just zeroing the non-shared state on return instead
 
 Exceptions:
 	* Rework of undefined instruction handling to avoid serialisation
 	  on global lock (this includes emulation of user accesses to the
 	  ID registers)
 
 Perf and PMU:
 	* Support for TLP filters in Hisilicon's PCIe PMU device
 	* Support for the DDR PMU present in Amlogic Meson G12 SoCs
 	* Support for the terribly-named "CoreSight PMU" architecture
 	  from Arm (and Nvidia's implementation of said architecture)
 
 Misc:
 	* Tighten up our boot protocol for systems with memory above
           52 bits physical
 	* Const-ify static keys to satisty jump label asm constraints
 	* Trivial FFA driver cleanups in preparation for v1.1 support
 	* Export the kernel_neon_* APIs as GPL symbols
 	* Harden our instruction generation routines against
 	  instrumentation
 	* A bunch of robustness improvements to our arch-specific selftests
 	* Minor cleanups and fixes all over (kbuild, kprobes, kfence, PMU, ...)
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "The highlights this time are support for dynamically enabling and
  disabling Clang's Shadow Call Stack at boot and a long-awaited
  optimisation to the way in which we handle the SVE register state on
  system call entry to avoid taking unnecessary traps from userspace.

  Summary:

  ACPI:
   - Enable FPDT support for boot-time profiling
   - Fix CPU PMU probing to work better with PREEMPT_RT
   - Update SMMUv3 MSI DeviceID parsing to latest IORT spec
   - APMT support for probing Arm CoreSight PMU devices

  CPU features:
   - Advertise new SVE instructions (v2.1)
   - Advertise range prefetch instruction
   - Advertise CSSC ("Common Short Sequence Compression") scalar
     instructions, adding things like min, max, abs, popcount
   - Enable DIT (Data Independent Timing) when running in the kernel
   - More conversion of system register fields over to the generated
     header

  CPU misfeatures:
   - Workaround for Cortex-A715 erratum #2645198

  Dynamic SCS:
   - Support for dynamic shadow call stacks to allow switching at
     runtime between Clang's SCS implementation and the CPU's pointer
     authentication feature when it is supported (complete with scary
     DWARF parser!)

  Tracing and debug:
   - Remove static ftrace in favour of, err, dynamic ftrace!
   - Seperate 'struct ftrace_regs' from 'struct pt_regs' in core ftrace
     and existing arch code
   - Introduce and implement FTRACE_WITH_ARGS on arm64 to replace the
     old FTRACE_WITH_REGS
   - Extend 'crashkernel=' parameter with default value and fallback to
     placement above 4G physical if initial (low) allocation fails

  SVE:
   - Optimisation to avoid disabling SVE unconditionally on syscall
     entry and just zeroing the non-shared state on return instead

  Exceptions:
   - Rework of undefined instruction handling to avoid serialisation on
     global lock (this includes emulation of user accesses to the ID
     registers)

  Perf and PMU:
   - Support for TLP filters in Hisilicon's PCIe PMU device
   - Support for the DDR PMU present in Amlogic Meson G12 SoCs
   - Support for the terribly-named "CoreSight PMU" architecture from
     Arm (and Nvidia's implementation of said architecture)

  Misc:
   - Tighten up our boot protocol for systems with memory above 52 bits
     physical
   - Const-ify static keys to satisty jump label asm constraints
   - Trivial FFA driver cleanups in preparation for v1.1 support
   - Export the kernel_neon_* APIs as GPL symbols
   - Harden our instruction generation routines against instrumentation
   - A bunch of robustness improvements to our arch-specific selftests
   - Minor cleanups and fixes all over (kbuild, kprobes, kfence, PMU, ...)"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (151 commits)
  arm64: kprobes: Return DBG_HOOK_ERROR if kprobes can not handle a BRK
  arm64: kprobes: Let arch do_page_fault() fix up page fault in user handler
  arm64: Prohibit instrumentation on arch_stack_walk()
  arm64:uprobe fix the uprobe SWBP_INSN in big-endian
  arm64: alternatives: add __init/__initconst to some functions/variables
  arm_pmu: Drop redundant armpmu->map_event() in armpmu_event_init()
  kselftest/arm64: Allow epoll_wait() to return more than one result
  kselftest/arm64: Don't drain output while spawning children
  kselftest/arm64: Hold fp-stress children until they're all spawned
  arm64/sysreg: Remove duplicate definitions from asm/sysreg.h
  arm64/sysreg: Convert ID_DFR1_EL1 to automatic generation
  arm64/sysreg: Convert ID_DFR0_EL1 to automatic generation
  arm64/sysreg: Convert ID_AFR0_EL1 to automatic generation
  arm64/sysreg: Convert ID_MMFR5_EL1 to automatic generation
  arm64/sysreg: Convert MVFR2_EL1 to automatic generation
  arm64/sysreg: Convert MVFR1_EL1 to automatic generation
  arm64/sysreg: Convert MVFR0_EL1 to automatic generation
  arm64/sysreg: Convert ID_PFR2_EL1 to automatic generation
  arm64/sysreg: Convert ID_PFR1_EL1 to automatic generation
  arm64/sysreg: Convert ID_PFR0_EL1 to automatic generation
  ...
2022-12-12 09:50:05 -08:00
Ard Biesheuvel
a37dac5c5d arm64: efi: Limit allocations to 48-bit addressable physical region
The UEFI spec does not mention or reason about the configured size of
the virtual address space at all, but it does mention that all memory
should be identity mapped using a page size of 4 KiB.

This means that a LPA2 capable system that has any system memory outside
of the 48-bit addressable physical range and follows the spec to the
letter may serve page allocation requests from regions of memory that
the kernel cannot access unless it was built with LPA2 support and
enables it at runtime.

So let's ensure that all page allocations are limited to the 48-bit
range.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-12-07 19:50:44 +01:00
Ard Biesheuvel
29636a5ce8 efi: Put Linux specific magic number in the DOS header
GRUB currently relies on the magic number in the image header of ARM and
arm64 EFI kernel images to decide whether or not the image in question
is a bootable kernel.

However, the purpose of the magic number is to identify the image as one
that implements the bare metal boot protocol, and so GRUB, which only
does EFI boot, is limited unnecessarily to booting images that could
potentially be booted in a non-EFI manner as well.

This is problematic for the new zboot decompressor image format, as it
can only boot in EFI mode, and must therefore not use the bare metal
boot magic number in its header.

For this reason, the strict magic number was dropped from GRUB, to
permit essentially any kind of EFI executable to be booted via the
'linux' command, blurring the line between the linux loader and the
chainloader.

So let's use the same field in the DOS header that RISC-V and arm64
already use for their 'bare metal' magic numbers to store a 'generic
Linux kernel' magic number, which can be used to identify bootable
kernel images in PE format which don't necessarily implement a bare
metal boot protocol in the same binary. Note that, in the context of
EFI, the MS-DOS header is only described in terms of the fields that it
shares with the hybrid PE/COFF image format, (i.e., the MS-DOS EXE magic
number at offset #0 and the PE header offset at byte offset #0x3c).
Since we aim for compatibility with EFI only, and not with MS-DOS or
MS-Windows, we can use the remaining space in the MS-DOS header however
we want.

Let's set the generic magic number for x86 images as well: existing
bootloaders already have their own methods to identify x86 Linux images
that can be booted in a non-EFI manner, and having the magic number in
place there will ease any future transitions in loader implementations
to merge the x86 and non-x86 EFI boot paths.

Note that 32-bit ARM already uses the same location in the header for a
different purpose, but the ARM support is already widely implemented and
the EFI zboot decompressor is not available on ARM anyway, so we just
disregard it here.

Acked-by: Leif Lindholm <quic_llindhol@quicinc.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-12-05 09:31:46 +01:00
Ard Biesheuvel
e346bebbd3 efi: libstub: Always enable initrd command line loader and bump version
In preparation for setting a cross-architecture baseline for EFI boot
support, remove the Kconfig option that permits the command line initrd
loader to be disabled. Also, bump the minor version so that any image
built with the new version can be identified as supporting this.

Acked-by: Leif Lindholm <quic_llindhol@quicinc.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-12-01 16:08:18 +01:00
Jason A. Donenfeld
a89474aaf7 efi: stub: use random seed from EFI variable
EFI has a rather unique benefit that it has access to some limited
non-volatile storage, where the kernel can store a random seed. Read
that seed in EFISTUB and concatenate it with other seeds we wind up
passing onward to the kernel in the configuration table. This is
complementary to the current other two sources - previous bootloaders,
and the EFI RNG protocol.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
[ardb: check for non-NULL RNG protocol pointer, call GetVariable()
       without buffer first to obtain the size]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-12-01 09:51:21 +01:00
Ard Biesheuvel
4b52016247 x86/boot/compressed, efi: Merge multiple definitions of image_offset into one
There is no need for head_32.S and head_64.S both declaring a copy of
the global 'image_offset' variable, so drop those and make the extern C
declaration the definition.

When image_offset is moved to the .c file, it needs to be placed
particularly in the .data section because it lands by default in the
.bss section which is cleared too late, in .Lrelocated, before the first
access to it and thus garbage gets read, leading to SEV guests exploding
in early boot.

This happens only when the SEV guest kernel is loaded through grub. If
supplied with qemu's -kernel command line option, that memory is always
cleared upfront by qemu and all is fine there.

  [ bp: Expand commit message with SEV aspect. ]

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20221122161017.2426828-8-ardb@kernel.org
2022-11-24 08:55:55 +01:00
Ard Biesheuvel
196dff2712 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>
2022-11-18 10:19:55 +01:00
Jialin Zhang
d981a88c16 efi: libstub: fix efi_load_initrd_dev_path() kernel-doc comment
commit f4dc7fffa987 ("efi: libstub: unify initrd loading between
architectures") merge the first and the second parameters into a
struct without updating the kernel-doc. Let's fix it.

Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-18 09:14:09 +01:00
Ard Biesheuvel
f8a31244d7 efi: libstub: Add mixed mode support to command line initrd loader
Now that we have support for calling protocols that need additional
marshalling for mixed mode, wire up the initrd command line loader.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-18 09:14:08 +01:00
Ard Biesheuvel
a61962d8e7 efi: libstub: Permit mixed mode return types other than efi_status_t
Rework the EFI stub macro wrappers around protocol method calls and
other indirect calls in order to allow return types other than
efi_status_t. This means the widening should be conditional on whether
or not the return type is efi_status_t, and should be omitted otherwise.

Also, switch to _Generic() to implement the type based compile time
conditionals, which is more concise, and distinguishes between
efi_status_t and u64 properly.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-18 09:14:08 +01:00
Ard Biesheuvel
7091298554 efi: libstub: Implement devicepath support for initrd commandline loader
Currently, the initrd= command line option to the EFI stub only supports
loading files that reside on the same volume as the loaded image, which
is not workable for loaders like GRUB that don't even implement the
volume abstraction (EFI_SIMPLE_FILE_SYSTEM_PROTOCOL), and load the
kernel from an anonymous buffer in memory. For this reason, another
method was devised that relies on the LoadFile2 protocol.

However, the command line loader is rather useful when using the UEFI
shell or other generic loaders that have no awareness of Linux specific
protocols so let's make it a bit more flexible, by permitting textual
device paths to be provided to initrd= as well, provided that they refer
to a file hosted on a EFI_SIMPLE_FILE_SYSTEM_PROTOCOL volume. E.g.,

  initrd=PciRoot(0x0)/Pci(0x3,0x0)/HD(1,MBR,0xBE1AFDFA,0x3F,0xFBFC1)/rootfs.cpio.gz

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-18 09:14:08 +01:00
Ard Biesheuvel
9cf42bca30 efi: libstub: use EFI_LOADER_CODE region when moving the kernel in memory
The EFI spec is not very clear about which permissions are being given
when allocating pages of a certain type. However, it is quite obvious
that EFI_LOADER_CODE is more likely to permit execution than
EFI_LOADER_DATA, which becomes relevant once we permit booting the
kernel proper with the firmware's 1:1 mapping still active.

Ostensibly, recent systems such as the Surface Pro X grant executable
permissions to EFI_LOADER_CODE regions but not EFI_LOADER_DATA regions.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-18 09:14:08 +01:00
Ard Biesheuvel
977122898e Merge tag 'efi-zboot-direct-for-v6.2' into efi/next 2022-11-18 09:13:57 +01:00
Ard Biesheuvel
550b33cfd4 arm64: efi: Force the use of SetVirtualAddressMap() on Altra machines
Ampere Altra machines are reported to misbehave when the SetTime() EFI
runtime service is called after ExitBootServices() but before calling
SetVirtualAddressMap(). Given that the latter is horrid, pointless and
explicitly documented as optional by the EFI spec, we no longer invoke
it at boot if the configured size of the VA space guarantees that the
EFI runtime memory regions can remain mapped 1:1 like they are at boot
time.

On Ampere Altra machines, this results in SetTime() calls issued by the
rtc-efi driver triggering synchronous exceptions during boot.  We can
now recover from those without bringing down the system entirely, due to
commit 23715a26c8d81291 ("arm64: efi: Recover from synchronous
exceptions occurring in firmware"). However, it would be better to avoid
the issue entirely, given that the firmware appears to remain in a funny
state after this.

So attempt to identify these machines based on the 'family' field in the
type #1 SMBIOS record, and call SetVirtualAddressMap() unconditionally
in that case.

Tested-by: Alexandru Elisei <alexandru.elisei@gmail.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-10 23:14:14 +01:00
Ard Biesheuvel
68c76ad4a9 arm64: unwind: add asynchronous unwind tables to kernel and modules
Enable asynchronous unwind table generation for both the core kernel as
well as modules, and emit the resulting .eh_frame sections as init code
so we can use the unwind directives for code patching at boot or module
load time.

This will be used by dynamic shadow call stack support, which will rely
on code patching rather than compiler codegen to emit the shadow call
stack push and pop instructions.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20221027155908.1940624-2-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2022-11-09 18:06:35 +00:00
Ard Biesheuvel
c51e97e7f1 efi: libstub: Merge zboot decompressor with the ordinary stub
Even though our EFI zboot decompressor is pedantically spec compliant
and idiomatic for EFI image loaders, calling LoadImage() and
StartImage() for the nested image is a bit of a burden. Not only does it
create workflow issues for the distros (as both the inner and outer
PE/COFF images need to be signed for secure boot), it also copies the
image around in memory numerous times:
- first, the image is decompressed into a buffer;
- the buffer is consumed by LoadImage(), which copies the sections into
  a newly allocated memory region to hold the executable image;
- once the EFI stub is invoked by StartImage(), it will also move the
  image in memory in case of KASLR, mirrored memory or if the image must
  execute from a certain a priori defined address.

There are only two EFI spec compliant ways to load code into memory and
execute it:
- use LoadImage() and StartImage(),
- call ExitBootServices() and take ownership of the entire system, after
  which anything goes.

Given that the EFI zboot decompressor always invokes the EFI stub, and
given that both are built from the same set of objects, let's merge the
two, so that we can avoid LoadImage()/StartImage but still load our
image into memory without breaking the above rules.

This also means we can decompress the image directly into its final
location, which could be randomized or meet other platform specific
constraints that LoadImage() does not know how to adhere to. It also
means that, even if the encapsulated image still has the EFI stub
incorporated as well, it does not need to be signed for secure boot when
wrapping it in the EFI zboot decompressor.

In the future, we might decide to retire the EFI stub attached to the
decompressed image, but for the time being, they can happily coexist.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:04 +01:00
Ard Biesheuvel
d729b554e1 efi/loongarch: libstub: Split off kernel image relocation for builtin stub
The LoongArch build of the EFI stub is part of the core kernel image, and
therefore accesses section markers directly when it needs to figure out
the size of the various section.

The zboot decompressor does not have access to those symbols, but
doesn't really need that either. So let's move handle_kernel_image()
into a separate file (or rather, move everything else into a separate
file) so that the zboot build does not pull in unused code that links to
symbols that it does not define.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:03 +01:00
Ard Biesheuvel
0efb61c89f efi/loongarch: Don't jump to kernel entry via the old image
Currently, the EFI entry code for LoongArch is set up to copy the
executable image to the preferred offset, but instead of branching
directly into that image, it branches to the local copy of kernel_entry,
and relies on the logic in that function to switch to the link time
address instead.

This is a bit sloppy, and not something we can support once we merge the
EFI decompressor with the EFI stub. So let's clean this up a bit, by
adding a helper that computes the offset of kernel_entry from the start
of the image, and simply adding the result to VMLINUX_LOAD_ADDRESS.

And considering that we cannot execute from anywhere else anyway, let's
avoid efi_relocate_kernel() and just allocate the pages instead.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:03 +01:00
Ard Biesheuvel
d9ffe524a5 efi/arm64: libstub: Split off kernel image relocation for builtin stub
The arm64 build of the EFI stub is part of the core kernel image, and
therefore accesses section markers directly when it needs to figure out
the size of the various section.

The zboot decompressor does not have access to those symbols, but
doesn't really need that either. So let's move handle_kernel_image()
into a separate file (or rather, move everything else into a separate
file) so that the zboot build does not pull in unused code that links to
symbols that it does not define.

While at it, introduce a helper routine that the generic zboot loader
will need to invoke after decompressing the image but before invoking
it, to ensure that the I-side view of memory is consistent.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:03 +01:00
Ard Biesheuvel
f1a116c055 efi/riscv: libstub: Split off kernel image relocation for builtin stub
The RISC-V build of the EFI stub is part of the core kernel image, and
therefore accesses section markers directly when it needs to figure out
the size of the various section.

The zboot decompressor does not have access to those symbols, but
doesn't really need that either. So let's move handle_kernel_image()
into a separate file (or rather, move everything else into a separate
file) so that the zboot build does not pull in unused code that links to
symbols that it does not define.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:03 +01:00
Ard Biesheuvel
895bc3a135 efi: libstub: Factor out min alignment and preferred kernel load address
Factor out the expressions that describe the preferred placement of the
loaded image as well as the minimum alignment so we can reuse them in
the decompressor.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:03 +01:00
Ard Biesheuvel
1f1ba325a2 efi: libstub: Add image code and data size to the zimage metadata
In order to be able to switch from LoadImage() [which treats the
supplied PE/COFF image as file input only, and reconstructs the memory
image based on the section descriptors] to a mode where we allocate the
memory directly, and invoke the image in place, we need to now how much
memory to allocate beyond the end of the image. So copy this information
from the payload's PE/COFF header to the end of the compressed version
of the payload, so that the decompressor app can access it before
performing the decompression itself.

We'll also need to size of the code region once we switch arm64 to
jumping to the kernel proper with MMU and caches enabled, so let's
capture that information as well. Note that SizeOfCode does not account
for the header, so we need SizeOfHeaders as well.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:03 +01:00
Ard Biesheuvel
42c8ea3dca efi: libstub: Factor out EFI stub entrypoint into separate file
In preparation for allowing the EFI zboot decompressor to reuse most of
the EFI stub machinery, factor out the actual EFI PE/COFF entrypoint
into a separate file.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:03 +01:00
Ard Biesheuvel
da8dd0c75b efi: libstub: Provide local implementations of strrchr() and memchr()
Clone the implementations of strrchr() and memchr() in lib/string.c so
we can use them in the standalone zboot decompressor app. These routines
are used by the FDT handling code.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:02 +01:00
Ard Biesheuvel
732ea9db9d 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>
2022-11-09 12:42:02 +01:00
Ard Biesheuvel
2e6fa86f2d efi: libstub: Enable efi_printk() in zboot decompressor
Split the efi_printk() routine into its own source file, and provide
local implementations of strlen() and strnlen() so that the standalone
zboot app can efi_err and efi_info etc.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:02 +01:00
Ard Biesheuvel
52dce39cd2 efi: libstub: Clone memcmp() into the stub
We will no longer be able to call into the kernel image once we merge
the decompressor with the EFI stub, so we need our own implementation of
memcmp(). Let's add the one from lib/string.c and simplify it.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:02 +01:00
Ard Biesheuvel
fa882a1389 efi: libstub: Use local strncmp() implementation unconditionally
In preparation for moving the EFI stub functionality into the zboot
decompressor, switch to the stub's implementation of strncmp()
unconditionally.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:02 +01:00
Ard Biesheuvel
4ef806096b arm64: efi: Move efi-entry.S into the libstub source directory
We will be sharing efi-entry.S with the zboot decompressor build, which
does not link against vmlinux directly. So move it into the libstub
source directory so we can include in the libstub static library.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2022-11-09 12:42:01 +01:00
Ard Biesheuvel
aaeb3fc614 arm64: efi: Move dcache cleaning of loaded image out of efi_enter_kernel()
The efi_enter_kernel() routine will be shared between the existing EFI
stub and the zboot decompressor, and the version of
dcache_clean_to_poc() that the core kernel exports to the stub will not
be available in the latter case.

So move the handling into the .c file which will remain part of the stub
build that integrates directly with the kernel proper.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2022-11-09 12:42:01 +01:00
Ard Biesheuvel
0d60ffeec5 efi: libstub: Deduplicate ftrace command line argument filtering
No need for the same pattern to be used four times for each architecture
individually if we can just apply it once later.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:01 +01:00
Ard Biesheuvel
48b9491cfe efi: libstub: Drop handling of EFI properties table
The EFI properties table was a short lived experiment that never saw the
light of day on non-x86 (if at all) so let's drop the handling of it.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:01 +01:00
Ard Biesheuvel
085e2ff9ae efi: libstub: Drop randomization of runtime memory map
Randomizing the UEFI runtime memory map requires the use of the
SetVirtualAddressMap() EFI boot service, which we prefer to avoid. So
let's drop randomization, which was already problematic in combination
with hibernation, which means that distro kernels never enabled it in
the first place.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09 12:42:01 +01:00
Ard Biesheuvel
7d866e38c7 efi: random: Use 'ACPI reclaim' memory for random seed
EFI runtime services data is guaranteed to be preserved by the OS,
making it a suitable candidate for the EFI random seed table, which may
be passed to kexec kernels as well (after refreshing the seed), and so
we need to ensure that the memory is preserved without support from the
OS itself.

However, runtime services data is intended for allocations that are
relevant to the implementations of the runtime services themselves, and
so they are unmapped from the kernel linear map, and mapped into the EFI
page tables that are active while runtime service invocations are in
progress. None of this is needed for the RNG seed.

So let's switch to EFI 'ACPI reclaim' memory: in spite of the name,
there is nothing exclusively ACPI about it, it is simply a type of
allocation that carries firmware provided data which may or may not be
relevant to the OS, and it is left up to the OS to decide whether to
reclaim it after having consumed its contents.

Given that in Linux, we never reclaim these allocations, it is a good
choice for the EFI RNG seed, as the allocation is guaranteed to survive
kexec reboots.

One additional reason for changing this now is to align it with the
upcoming recommendation for EFI bootloader provided RNG seeds, which
must not use EFI runtime services code/data allocations.

Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2022-10-24 10:23:28 +02:00