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2022-10-21efi: runtime: Don't assume virtual mappings are missing if VA == PA == 0Ard Biesheuvel1-4/+4
The generic EFI stub can be instructed to avoid SetVirtualAddressMap(), and simply run with the firmware's 1:1 mapping. In this case, it populates the virtual address fields of the runtime regions in the memory map with the physical address of each region, so that the mapping code has to be none the wiser. Only if SetVirtualAddressMap() fails, the virtual addresses are wiped and the kernel code knows that the regions cannot be mapped. However, wiping amounts to setting it to zero, and if a runtime region happens to live at physical address 0, its valid 1:1 mapped virtual address could be mistaken for a wiped field, resulting on loss of access to the EFI services at runtime. So let's only assume that VA == 0 means 'no runtime services' if the region in question does not live at PA 0x0. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-27efi: libstub: remove DT dependency from generic stubArd Biesheuvel1-4/+57
Refactor the generic EFI stub entry code so that all the dependencies on device tree are abstracted and hidden behind a generic efi_boot_kernel() routine that can also be implemented in other ways. This allows users of the generic stub to avoid using FDT for passing information to the core kernel. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-27efi: libstub: unify initrd loading between architecturesArd Biesheuvel1-31/+10
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>
2022-09-26efi: libstub: simplify efi_get_memory_map() and struct efi_boot_memmapArd Biesheuvel1-21/+16
Currently, struct efi_boot_memmap is a struct that is passed around between callers of efi_get_memory_map() and the users of the resulting data, and which carries pointers to various variables whose values are provided by the EFI GetMemoryMap() boot service. This is overly complex, and it is much easier to carry these values in the struct itself. So turn the struct into one that carries these data items directly, including a flex array for the variable number of EFI memory descriptors that the boot service may return. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-26efi: libstub: avoid efi_get_memory_map() for allocating the virt mapArd Biesheuvel1-22/+14
The virt map is a set of efi_memory_desc_t descriptors that are passed to SetVirtualAddressMap() to inform the firmware about the desired virtual mapping of the regions marked as EFI_MEMORY_RUNTIME. The only reason we currently call the efi_get_memory_map() helper is that it gives us an allocation that is guaranteed to be of sufficient size. However, efi_get_memory_map() has grown some additional complexity over the years, and today, we're actually better off calling the EFI boot service directly with a zero size, which tells us how much memory should be enough for the virt map. While at it, avoid creating the VA map allocation if we will not be using it anyway, i.e., if efi_novamap is true. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-20efi: libstub: drop pointless get_memory_map() callArd Biesheuvel1-8/+0
Currently, the non-x86 stub code calls get_memory_map() redundantly, given that the data it returns is never used anywhere. So drop the call. Cc: <stable@vger.kernel.org> # v4.14+ Fixes: 24d7c494ce46 ("efi/arm-stub: Round up FDT allocation to mapping size") Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-10-05efi/libstub: Simplify "Exiting bootservices" messageHeinrich Schuchardt1-1/+1
The message "Exiting boot services and installing virtual address map...\n" is even shown if we have efi=novamap on the command line or the firmware does not provide EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP. To avoid confusion just print "Exiting boot services...\n" Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-12-09efi: stub: get rid of efi_get_max_fdt_addr()Ard Biesheuvel1-2/+1
Now that ARM started following the example of arm64 and RISC-V, and no longer imposes any restrictions on the placement of the FDT in memory at boot, we no longer need per-arch implementations of efi_get_max_fdt_addr() to factor out the differences. So get rid of it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Atish Patra <atish.patra@wdc.com> Link: https://lore.kernel.org/r/20201029134901.9773-1-ardb@kernel.org
2020-09-29efi/arm64: libstub: Deal gracefully with EFI_RNG_PROTOCOL failureArd Biesheuvel1-3/+1
Currently, on arm64, we abort on any failure from efi_get_random_bytes() other than EFI_NOT_FOUND when it comes to setting the physical seed for KASLR, but ignore such failures when obtaining the seed for virtual KASLR or for early seeding of the kernel's entropy pool via the config table. This is inconsistent, and may lead to unexpected boot failures. So let's permit any failure for the physical seed, and simply report the error code if it does not equal EFI_NOT_FOUND. Cc: <stable@vger.kernel.org> # v5.8+ Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-01efi/libstub: Move pr_efi/pr_efi_err into efi namespaceArvind Sankar1-8/+8
Rename pr_efi to efi_info and pr_efi_err to efi_err to make it more obvious that they are part of the EFI stub and not generic printk infra. Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200430182843.2510180-4-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-24efi/libstub: Drop __pure getters for EFI stub optionsArd Biesheuvel1-1/+1
The practice of using __pure getter functions to access global variables in the EFI stub dates back to the time when we had to carefully prevent GOT entries from being emitted, because we could not rely on the toolchain to do this for us. Today, we use the hidden visibility pragma for all EFI stub source files, which now all live in the same subdirectory, and we apply a sanity check on the objects, so we can get rid of these getter functions and simply refer to global data objects directly. So switch over the remaining boolean variables carrying options set on the kernel command line. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-24efi/libstub: Drop __pure getter for efi_system_tableArd Biesheuvel1-3/+3
The practice of using __pure getter functions to access global variables in the EFI stub dates back to the time when we had to carefully prevent GOT entries from being emitted, because we could not rely on the toolchain to do this for us. Today, we use the hidden visibility pragma for all EFI stub source files, which now all live in the same subdirectory, and we apply a sanity check on the objects, so we can get rid of these getter functions and simply refer to global data objects directly. Start with efi_system_table(), and convert it into a global variable. While at it, make it a pointer-to-const, because we can. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Simplify efi_high_alloc() and rename to efi_allocate_pages()Ard Biesheuvel1-2/+1
The implementation of efi_high_alloc() uses a complicated way of traversing the memory map to find an available region that is located as close as possible to the provided upper limit, and calls AllocatePages subsequently to create the allocation at that exact address. This is precisely what the EFI_ALLOCATE_MAX_ADDRESS allocation type argument to AllocatePages() does, and considering that EFI_ALLOC_ALIGN only exceeds EFI_PAGE_SIZE on arm64, let's use AllocatePages() directly and implement the alignment using code that the compiler can remove if it does not exceed EFI_PAGE_SIZE. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub/arm: Relax FDT alignment requirementArd Biesheuvel1-5/+1
The arm64 kernel no longer requires the FDT blob to fit inside a naturally aligned 2 MB memory block, so remove the code that aligns the allocation to 2 MB. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2019-12-25efi/libstub: Remove 'sys_table_arg' from all function prototypesArd Biesheuvel1-20/+17
We have a helper efi_system_table() that gives us the address of the EFI system table in memory, so there is no longer point in passing it around from each function to the next. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-20-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-12-25efi/libstub: Drop sys_table_arg from printk routinesArd Biesheuvel1-8/+8
As a first step towards getting rid of the need to pass around a function parameter 'sys_table_arg' pointing to the EFI system table, remove the references to it in the printing code, which is represents the majority of the use cases. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: James Morse <james.morse@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224151025.32482-19-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-24Abstract out support for locating an EFI config tableMatthew Garrett1-18/+9
We want to grab a pointer to the TPM final events table, so abstract out the existing code for finding an FDT table and make it generic. Signed-off-by: Matthew Garrett <mjg59@google.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> 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>
2019-02-04efi/arm/arm64: Allow SetVirtualAddressMap() to be omittedArd Biesheuvel1-0/+3
The UEFI spec revision 2.7 errata A section 8.4 has the following to say about the virtual memory runtime services: "This section contains function definitions for the virtual memory support that may be optionally used by an operating system at runtime. If an operating system chooses to make EFI runtime service calls in a virtual addressing mode instead of the flat physical mode, then the operating system must use the services in this section to switch the EFI runtime services from flat physical addressing to virtual addressing." So it is pretty clear that calling SetVirtualAddressMap() is entirely optional, and so there is no point in doing so unless it achieves anything useful for us. This is not the case for 64-bit ARM. The identity mapping used by the firmware is arbitrarily converted into another permutation of userland addresses (i.e., bits [63:48] cleared), and the runtime code could easily deal with the original layout in exactly the same way as it deals with the converted layout. However, due to constraints related to page size differences if the OS is not running with 4k pages, and related to systems that may expose the individual sections of PE/COFF runtime modules as different memory regions, creating the virtual layout is a bit fiddly, and requires us to sort the memory map and reason about adjacent regions with identical memory types etc etc. So the obvious fix is to stop calling SetVirtualAddressMap() altogether on arm64 systems. However, to avoid surprises, which are notoriously hard to diagnose when it comes to OS<->firmware interactions, let's start by making it an opt-out feature, and implement support for the 'efi=novamap' kernel command line parameter on ARM and arm64 systems. ( Note that 32-bit ARM generally does require SetVirtualAddressMap() to be used, given that the physical memory map and the kernel virtual address map are not guaranteed to be non-overlapping like on arm64. However, having support for efi=novamap,noruntime on 32-bit ARM, combined with the recently proposed support for earlycon=efifb, is likely to be useful to diagnose boot issues on such systems if they have no accessible serial port. ) Tested-by: Jeffrey Hugo <jhugo@codeaurora.org> Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org> Tested-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Alexander Graf <agraf@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> 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/20190202094119.13230-8-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-04efi: Replace GPL license boilerplate with SPDX headersArd Biesheuvel1-4/+1
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/fdt: Apply more cleanupsIngo Molnar1-56/+51
Apply a number of cleanups: - Introduce fdt_setprop_*var() helper macros to simplify and shorten repetitive sequences - this also makes it less likely that the wrong variable size is passed in. This change makes a lot of the property-setting calls single-line and easier to read. - Harmonize comment style: capitalization, punctuation, whitespaces, etc. - Fix some whitespace noise in the libstub Makefile which I happened to notice. - Use the standard tabular initialization style: - map.map = &runtime_map; - map.map_size = &map_size; - map.desc_size = &desc_size; - map.desc_ver = &desc_ver; - map.key_ptr = &mmap_key; - map.buff_size = &buff_size; + map.map = &runtime_map; + map.map_size = &map_size; + map.desc_size = &desc_size; + map.desc_ver = &desc_ver; + map.key_ptr = &mmap_key; + map.buff_size = &buff_size; - Use tabular structure definition for better readability. - Make all pr*() lines single-line, even if they marginally exceed 80 cols - this makes them visually less intrusive. - Unbreak line breaks into single lines when the length exceeds 80 cols only marginally, for better readability. - Move assignment closer to the actual usage site. - Plus some other smaller cleanups, spelling fixes, etc. No change in functionality intended. [ ardb: move changes to upstream libfdt into local header. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> 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/20190202094119.13230-6-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-30efi/fdt: Simplify the get_fdt() flowJulien Thierry1-12/+13
Reorganize the get_fdt() lookup loop, clearly showing that: - Nothing is done for table entries that do not have fdt_guid - Once an entry with fdt_guid is found, break out of the loop No functional changes. Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Julien Thierry <julien.thierry@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: Jon Hunter <jonathanh@nvidia.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marc Zyngier <marc.zyngier@arm.com> 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/20181129171230.18699-4-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-30efi/fdt: Indentation fixJulien Thierry1-2/+3
Closing bracket seems to end a for statement when it is actually ending the contained if. Add some brackets to have clear delimitation of each scope. No functional change/fix, just fix the indentation. Signed-off-by: Julien Thierry <julien.thierry@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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marc Zyngier <marc.zyngier@arm.com> 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/20181129171230.18699-3-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-15efi/arm/libstub: Pack FDT after populating itArd Biesheuvel1-0/+4
Commit: 24d7c494ce46 ("efi/arm-stub: Round up FDT allocation to mapping size") increased the allocation size for the FDT image created by the stub to a fixed value of 2 MB, to simplify the former code that made several attempts with increasing values for the size. This is reasonable given that the allocation is of type EFI_LOADER_DATA, which is released to the kernel unless it is explicitly memblock_reserve()d by the early boot code. However, this allocation size leaked into the 'size' field of the FDT header metadata, and so the entire allocation remains occupied by the device tree binary, even if most of it is not used to store device tree information. So call fdt_pack() to shrink the FDT data structure to its minimum size after populating all the fields, so that the remaining memory is no longer wasted. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: <stable@vger.kernel.org> # v4.12+ 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: 24d7c494ce46 ("efi/arm-stub: Round up FDT allocation to mapping size") Link: http://lkml.kernel.org/r/20181114175544.12860-4-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-05Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxLinus Torvalds1-2/+26
Pull arm64 updates from Catalin Marinas: - kdump support, including two necessary memblock additions: memblock_clear_nomap() and memblock_cap_memory_range() - ARMv8.3 HWCAP bits for JavaScript conversion instructions, complex numbers and weaker release consistency - arm64 ACPI platform MSI support - arm perf updates: ACPI PMU support, L3 cache PMU in some Qualcomm SoCs, Cortex-A53 L2 cache events and DTLB refills, MAINTAINERS update for DT perf bindings - architected timer errata framework (the arch/arm64 changes only) - support for DMA_ATTR_FORCE_CONTIGUOUS in the arm64 iommu DMA API - arm64 KVM refactoring to use common system register definitions - remove support for ASID-tagged VIVT I-cache (no ARMv8 implementation using it and deprecated in the architecture) together with some I-cache handling clean-up - PE/COFF EFI header clean-up/hardening - define BUG() instruction without CONFIG_BUG * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits) arm64: Fix the DMA mmap and get_sgtable API with DMA_ATTR_FORCE_CONTIGUOUS arm64: Print DT machine model in setup_machine_fdt() arm64: pmu: Wire-up Cortex A53 L2 cache events and DTLB refills arm64: module: split core and init PLT sections arm64: pmuv3: handle pmuv3+ arm64: Add CNTFRQ_EL0 trap handler arm64: Silence spurious kbuild warning on menuconfig arm64: pmuv3: use arm_pmu ACPI framework arm64: pmuv3: handle !PMUv3 when probing drivers/perf: arm_pmu: add ACPI framework arm64: add function to get a cpu's MADT GICC table drivers/perf: arm_pmu: split out platform device probe logic drivers/perf: arm_pmu: move irq request/free into probe drivers/perf: arm_pmu: split cpu-local irq request/free drivers/perf: arm_pmu: rename irq request/free functions drivers/perf: arm_pmu: handle no platform_device drivers/perf: arm_pmu: simplify cpu_pmu_request_irqs() drivers/perf: arm_pmu: factor out pmu registration drivers/perf: arm_pmu: fold init into alloc drivers/perf: arm_pmu: define armpmu_init_fn ...
2017-04-05efi/libstub/arm*: Set default address and size cells values for an empty dtbSameer Goel1-2/+26
In cases where a device tree is not provided (ie ACPI based system), an empty fdt is generated by efistub. #address-cells and #size-cells are not set in the empty fdt, so they default to 1 (4 byte wide). This can be an issue on 64-bit systems where values representing addresses, etc may be 8 bytes wide as the default value does not align with the general requirements for an empty DTB, and is fragile when passed to other agents as extra care is required to read the entire width of a value. This issue is observed on Qualcomm Technologies QDF24XX platforms when kexec-tools inserts 64-bit addresses into the "linux,elfcorehdr" and "linux,usable-memory-range" properties of the fdt. When the values are later consumed, they are truncated to 32-bit. Setting #address-cells and #size-cells to 2 at creation of the empty fdt resolves the observed issue, and makes the fdt less fragile. Signed-off-by: Sameer Goel <sgoel@codeaurora.org> Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-04-05efi/arm-stub: Round up FDT allocation to mapping sizeArd Biesheuvel1-33/+24
The FDT is mapped via a fixmap entry that is at least 2 MB in size and 2 MB aligned on 4 KB page size kernels. On UEFI systems, the FDT allocation may share this 2 MB mapping with a reserved region (or another memory region that we should never map), unless we account for this in the size of the allocation (the alignment is already 2 MB) So instead of taking guesses at the needed space, simply allocate 2 MB immediately. The allocation will be recorded as EFI_LOADER_DATA, and the kernel only memblock_reserve()'s the actual size of the FDT, so the unused space will be released back to the kernel. Reviewed-By: Jeffrey Hugo <jhugo@codeaurora.org> Tested-by: Richard Ruigrok <rruigrok@codeaurora.org> 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/20170404160245.27812-6-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-01efi/fdt: Avoid FDT manipulation after ExitBootServices()Ard Biesheuvel1-11/+3
Some AArch64 UEFI implementations disable the MMU in ExitBootServices(), after which unaligned accesses to RAM are no longer supported. Commit: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") fixed an issue in the memory map handling of the stub FDT code, but inadvertently created an issue with such firmware, by moving some of the FDT manipulation to after the invocation of ExitBootServices(). Given that the stub's libfdt implementation uses the ordinary, accelerated string functions, which rely on hardware handling of unaligned accesses, manipulating the FDT with the MMU off may result in alignment faults. So fix the situation by moving the update_fdt_memmap() call into the callback function invoked by efi_exit_boot_services() right before it calls the ExitBootServices() UEFI service (which is arguably a better place for it anyway) Note that disabling the MMU in ExitBootServices() is not compliant with the UEFI spec, and carries great risk due to the fact that switching from cached to uncached memory accesses halfway through compiler generated code (i.e., involving a stack) can never be done in a way that is architecturally safe. Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Riku Voipio <riku.voipio@linaro.org> Cc: <stable@vger.kernel.org> Cc: mark.rutland@arm.com Cc: linux-efi@vger.kernel.org Cc: matt@codeblueprint.co.uk Cc: leif.lindholm@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-28efi/libstub/arm*: Pass latest memory map to the kernelArd Biesheuvel1-31/+56
As reported by James Morse, the current libstub code involving the annotated memory map only works somewhat correctly by accident, due to the fact that a pool allocation happens to be reused immediately, retaining its former contents on most implementations of the UEFI boot services. Instead of juggling memory maps, which makes the code more complex than it needs to be, simply put placeholder values into the FDT for the memory map parameters, and only write the actual values after ExitBootServices() has been called. Reported-by: James Morse <james.morse@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: <stable@vger.kernel.org> Cc: Jeffrey Hugo <jhugo@codeaurora.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-arm-kernel@lists.infradead.org Cc: linux-efi@vger.kernel.org Fixes: ed9cc156c42f ("efi/libstub: Use efi_exit_boot_services() in FDT") Link: http://lkml.kernel.org/r/1482587963-20183-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-05efi/libstub: Use efi_exit_boot_services() in FDTJeffrey Hugo1-10/+27
The FDT code directly calls ExitBootServices. This is inadvisable as the UEFI spec details a complex set of errors, race conditions, and API interactions that the caller of ExitBootServices must get correct. The FDT code does not handle EFI_INVALID_PARAMETER as required by the spec, which causes intermittent boot failures on the Qualcomm Technologies QDF2432. Call the efi_exit_boot_services() helper intead, which handles the EFI_INVALID_PARAMETER scenario properly. Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-05efi/libstub: Allocate headspace in efi_get_memory_map()Jeffrey Hugo1-5/+12
efi_get_memory_map() allocates a buffer to store the memory map that it retrieves. This buffer may need to be reused by the client after ExitBootServices() is called, at which point allocations are not longer permitted. To support this usecase, provide the allocated buffer size back to the client, and allocate some additional headroom to account for any reasonable growth in the map that is likely to happen between the call to efi_get_memory_map() and the client reusing the buffer. Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-04-15efi: ARM/arm64: ignore DT memory nodes instead of removing themArd Biesheuvel1-23/+1
There are two problems with the UEFI stub DT memory node removal routine: - it deletes nodes as it traverses the tree, which happens to work but is not supported, as deletion invalidates the node iterator; - deleting memory nodes entirely may discard annotations in the form of additional properties on the nodes. Since the discovery of DT memory nodes occurs strictly before the UEFI init sequence, we can simply clear the memblock memory table before parsing the UEFI memory map. This way, it is no longer necessary to remove the nodes, so we can remove that logic from the stub as well. Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-24arm64: efi: invoke EFI_RNG_PROTOCOL to supply KASLR randomnessArd Biesheuvel1-0/+14
Since arm64 does not use a decompressor that supplies an execution environment where it is feasible to some extent to provide a source of randomness, the arm64 KASLR kernel depends on the bootloader to supply some random bits in the /chosen/kaslr-seed DT property upon kernel entry. On UEFI systems, we can use the EFI_RNG_PROTOCOL, if supplied, to obtain some random bits. At the same time, use it to randomize the offset of the kernel Image in physical memory. Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-12-08treewide: Fix typos in printkMasanari Iida1-1/+1
This patch fix multiple spelling typos found in various part of kernel. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-10-12arm64/efi: remove /chosen/linux, uefi-stub-kern-ver DT propertyArd Biesheuvel1-9/+0
With the stub to kernel interface being promoted to a proper interface so that other agents than the stub can boot the kernel proper in EFI mode, we can remove the linux,uefi-stub-kern-ver field, considering that its original purpose was to prevent this from happening in the first place. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-04-01efi/libstub: Retrieve FDT size when loaded from UEFI config tableArd Biesheuvel1-1/+6
When allocating memory for the copy of the FDT that the stub modifies and passes to the kernel, it uses the current size as an estimate of how much memory to allocate, and increases it page by page if it turns out to be too small. However, when loading the FDT from a UEFI configuration table, the estimated size is left at its default value of zero, and the allocation loop runs starting from zero all the way up to the allocation size that finally fits the updated FDT. Instead, retrieve the size of the FDT from the FDT header when loading it from the UEFI config table. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Roy Franz <roy.franz@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-01-12arm64/efi: move SetVirtualAddressMap() to UEFI stubArd Biesheuvel1-3/+59
In order to support kexec, the kernel needs to be able to deal with the state of the UEFI firmware after SetVirtualAddressMap() has been called. To avoid having separate code paths for non-kexec and kexec, let's move the call to SetVirtualAddressMap() to the stub: this will guarantee us that it will only be called once (since the stub is not executed during kexec), and ensures that the UEFI state is identical between kexec and normal boot. This implies that the layout of the virtual mapping needs to be created by the stub as well. All regions are rounded up to a naturally aligned multiple of 64 KB (for compatibility with 64k pages kernels) and recorded in the UEFI memory map. The kernel proper reads those values and installs the mappings in a dedicated set of page tables that are swapped in during UEFI Runtime Services calls. Acked-by: Leif Lindholm <leif.lindholm@linaro.org> 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>
2014-09-09efi/arm64: Fix fdt-related memory reservationMark Salter1-1/+9
Commit 86c8b27a01cf: "arm64: ignore DT memreserve entries when booting in UEFI mode prevents early_init_fdt_scan_reserved_mem() from being called for arm64 kernels booting via UEFI. This was done because the kernel will use the UEFI memory map to determine reserved memory regions. That approach has problems in that early_init_fdt_scan_reserved_mem() also reserves the FDT itself and any node-specific reserved memory. By chance of some kernel configs, the FDT may be overwritten before it can be unflattened and the kernel will fail to boot. More subtle problems will result if the FDT has node specific reserved memory which is not really reserved. This patch has the UEFI stub remove the memory reserve map entries from the FDT as it does with the memory nodes. This allows early_init_fdt_scan_reserved_mem() to be called unconditionally so that the other needed reservations are made. Signed-off-by: Mark Salter <msalter@redhat.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-08-04Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+279
Pull EFI changes from Ingo Molnar: "Main changes in this cycle are: - arm64 efi stub fixes, preservation of FP/SIMD registers across firmware calls, and conversion of the EFI stub code into a static library - Ard Biesheuvel - Xen EFI support - Daniel Kiper - Support for autoloading the efivars driver - Lee, Chun-Yi - Use the PE/COFF headers in the x86 EFI boot stub to request that the stub be loaded with CONFIG_PHYSICAL_ALIGN alignment - Michael Brown - Consolidate all the x86 EFI quirks into one file - Saurabh Tangri - Additional error logging in x86 EFI boot stub - Ulf Winkelvos - Support loading initrd above 4G in EFI boot stub - Yinghai Lu - EFI reboot patches for ACPI hardware reduced platforms" * 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) efi/arm64: Handle missing virtual mapping for UEFI System Table arch/x86/xen: Silence compiler warnings xen: Silence compiler warnings x86/efi: Request desired alignment via the PE/COFF headers x86/efi: Add better error logging to EFI boot stub efi: Autoload efivars efi: Update stale locking comment for struct efivars arch/x86: Remove efi_set_rtc_mmss() arch/x86: Replace plain strings with constants xen: Put EFI machinery in place xen: Define EFI related stuff arch/x86: Remove redundant set_bit(EFI_MEMMAP) call arch/x86: Remove redundant set_bit(EFI_SYSTEM_TABLES) call efi: Introduce EFI_PARAVIRT flag arch/x86: Do not access EFI memory map if it is not available efi: Use early_mem*() instead of early_io*() arch/ia64: Define early_memunmap() x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag efi/reboot: Allow powering off machines using EFI efi/reboot: Add generic wrapper around EfiResetSystem() ...
2014-07-18efi: efistub: Convert into static libraryArd Biesheuvel1-0/+279
This patch changes both x86 and arm64 efistub implementations from #including shared .c files under drivers/firmware/efi to building shared code as a static library. The x86 code uses a stub built into the boot executable which uncompresses the kernel at boot time. In this case, the library is linked into the decompressor. In the arm64 case, the stub is part of the kernel proper so the library is linked into the kernel proper as well. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>