summaryrefslogtreecommitdiffstats
path: root/drivers/firmware/efi/libstub/arm-stub.c
AgeCommit message (Collapse)AuthorFilesLines
2017-02-07efi: Get and store the secure boot statusDavid Howells1-57/+6
Get the firmware's secure-boot status in the kernel boot wrapper and stash it somewhere that the main kernel image can find. The efi_get_secureboot() function is extracted from the ARM stub and (a) generalised so that it can be called from x86 and (b) made to use efi_call_runtime() so that it can be run in mixed-mode. For x86, it is stored in boot_params and can be overridden by the boot loader or kexec. This allows secure-boot mode to be passed on to a new kernel. Suggested-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1486380166-31868-5-git-send-email-ard.biesheuvel@linaro.org [ Small readability edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-01efi: Deduplicate efi_file_size() / _read() / _close()Lukas Wunner1-69/+0
There's one ARM, one x86_32 and one x86_64 version which can be folded into a single shared version by masking their differences with the shiny new efi_call_proto() macro. No functional change intended. Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1485868902-20401-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-13efi/arm*/libstub: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG tableArd Biesheuvel1-0/+2
Invoke the EFI_RNG_PROTOCOL protocol in the context of the stub and install the Linux-specific RNG seed UEFI config table. This will be picked up by the EFI routines in the core kernel to seed the kernel entropy pool. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20161112213237.8804-6-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28efi/arm*/libstub: Wire up GOP protocol to 'struct screen_info'Ard Biesheuvel1-0/+23
This adds the code to the ARM and arm64 versions of the UEFI stub to populate struct screen_info based on the information received from the firmware via the GOP protocol. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-23-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28efi/arm64: Check SetupMode when determining Secure Boot statusLinn Crosetto1-7/+25
According to the UEFI specification (version 2.5 Errata A, page 87): The platform firmware is operating in secure boot mode if the value of the SetupMode variable is 0 and the SecureBoot variable is set to 1. A platform cannot operate in secure boot mode if the SetupMode variable is set to 1. Check the value of the SetupMode variable when determining the state of Secure Boot. Plus also do minor cleanup, change sizeof() use to match kernel style guidelines. Signed-off-by: Linn Crosetto <linn@hpe.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roy Franz <roy.franz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-6-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28efi/arm64: Report unexpected errors when determining Secure Boot statusLinn Crosetto1-4/+18
Certain code in the boot path may require the ability to determine whether UEFI Secure Boot is definitely enabled, for example printing status to the console. Other code may need to know when UEFI Secure Boot is definitely disabled, for example restricting use of kernel parameters. If an unexpected error is returned from GetVariable() when querying the status of UEFI Secure Boot, return an error to the caller. This allows the caller to determine the definite state, and to take appropriate action if an expected error is returned. Signed-off-by: Linn Crosetto <linn@hpe.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roy Franz <roy.franz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-5-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-20Merge branch 'efi-core-for-linus' of ↵Linus Torvalds1-0/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI updates from Ingo Molnar: "The main changes are: - Use separate EFI page tables when executing EFI firmware code. This isolates the EFI context from the rest of the kernel, which has security and general robustness advantages. (Matt Fleming) - Run regular UEFI firmware with interrupts enabled. This is already the status quo under other OSs. (Ard Biesheuvel) - Various x86 EFI enhancements, such as the use of non-executable attributes for EFI memory mappings. (Sai Praneeth Prakhya) - Various arm64 UEFI enhancements. (Ard Biesheuvel) - ... various fixes and cleanups. The separate EFI page tables feature got delayed twice already, because it's an intrusive change and we didn't feel confident about it - third time's the charm we hope!" * 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) x86/mm/pat: Fix boot crash when 1GB pages are not supported by the CPU x86/efi: Only map kernel text for EFI mixed mode x86/efi: Map EFI_MEMORY_{XP,RO} memory region bits to EFI page tables x86/mm/pat: Don't implicitly allow _PAGE_RW in kernel_map_pages_in_pgd() efi/arm*: Perform hardware compatibility check efi/arm64: Check for h/w support before booting a >4 KB granular kernel efi/arm: Check for LPAE support before booting a LPAE kernel efi/arm-init: Use read-only early mappings efi/efistub: Prevent __init annotations from being used arm64/vmlinux.lds.S: Handle .init.rodata.xxx and .init.bss sections efi/arm64: Drop __init annotation from handle_kernel_image() x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings efi/runtime-wrappers: Run UEFI Runtime Services with interrupts enabled efi: Reformat GUID tables to follow the format in UEFI spec efi: Add Persistent Memory type name efi: Add NV memory attribute x86/efi: Show actual ending addresses in efi_print_memmap x86/efi/bgrt: Don't ignore the BGRT if the 'valid' bit is 0 efivars: Use to_efivar_entry efi: Runtime-wrapper: Get rid of the rtc_lock spinlock ...
2016-02-24arm64: efi: invoke EFI_RNG_PROTOCOL to supply KASLR randomnessArd Biesheuvel1-13/+27
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>
2016-02-22efi/arm*: Perform hardware compatibility checkArd Biesheuvel1-0/+4
Before proceeding with relocating the kernel and parsing the command line, insert a call to check_platform_features() to allow an arch specific check to be performed whether the current kernel can execute on the current hardware. Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Jeremy Linton <jeremy.linton@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1455712566-16727-11-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-14ARM: add UEFI stub supportRoy Franz1-1/+3
This patch adds EFI stub support for the ARM Linux kernel. The EFI stub operates similarly to the x86 and arm64 stubs: it is a shim between the EFI firmware and the normal zImage entry point, and sets up the environment that the zImage is expecting. This includes optionally loading the initrd and device tree from the system partition based on the kernel command line. Signed-off-by: Roy Franz <roy.franz@linaro.org> Tested-by: Ryan Harkin <ryan.harkin@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2015-10-01arm64/efi: Fix boot crash by not padding between EFI_MEMORY_RUNTIME regionsArd Biesheuvel1-15/+73
The new Properties Table feature introduced in UEFIv2.5 may split memory regions that cover PE/COFF memory images into separate code and data regions. Since these regions only differ in the type (runtime code vs runtime data) and the permission bits, but not in the memory type attributes (UC/WC/WT/WB), the spec does not require them to be aligned to 64 KB. Since the relative offset of PE/COFF .text and .data segments cannot be changed on the fly, this means that we can no longer pad out those regions to be mappable using 64 KB pages. Unfortunately, there is no annotation in the UEFI memory map that identifies data regions that were split off from a code region, so we must apply this logic to all adjacent runtime regions whose attributes only differ in the permission bits. So instead of rounding each memory region to 64 KB alignment at both ends, only round down regions that are not directly preceded by another runtime region with the same type attributes. Since the UEFI spec does not mandate that the memory map be sorted, this means we also need to sort it first. Note that this change will result in all EFI_MEMORY_RUNTIME regions whose start addresses are not aligned to the OS page size to be mapped with executable permissions (i.e., on kernels compiled with 64 KB pages). However, since these mappings are only active during the time that UEFI Runtime Services are being invoked, the window for abuse is rather small. Tested-by: Mark Salter <msalter@redhat.com> Tested-by: Mark Rutland <mark.rutland@arm.com> [UEFI 2.4 only] Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Reviewed-by: Mark Salter <msalter@redhat.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: <stable@vger.kernel.org> # v4.0+ Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443218539-7610-3-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01efi/libstub: Retrieve FDT size when loaded from UEFI config tableArd Biesheuvel1-4/+3
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>
2015-02-11Merge tag 'arm64-upstream' of ↵Linus Torvalds1-0/+59
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "arm64 updates for 3.20: - reimplementation of the virtual remapping of UEFI Runtime Services in a way that is stable across kexec - emulation of the "setend" instruction for 32-bit tasks (user endianness switching trapped in the kernel, SCTLR_EL1.E0E bit set accordingly) - compat_sys_call_table implemented in C (from asm) and made it a constant array together with sys_call_table - export CPU cache information via /sys (like other architectures) - DMA API implementation clean-up in preparation for IOMMU support - macros clean-up for KVM - dropped some unnecessary cache+tlb maintenance - CONFIG_ARM64_CPU_SUSPEND clean-up - defconfig update (CPU_IDLE) The EFI changes going via the arm64 tree have been acked by Matt Fleming. There is also a patch adding sys_*stat64 prototypes to include/linux/syscalls.h, acked by Andrew Morton" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (47 commits) arm64: compat: Remove incorrect comment in compat_siginfo arm64: Fix section mismatch on alloc_init_p[mu]d() arm64: Avoid breakage caused by .altmacro in fpsimd save/restore macros arm64: mm: use *_sect to check for section maps arm64: drop unnecessary cache+tlb maintenance arm64:mm: free the useless initial page table arm64: Enable CPU_IDLE in defconfig arm64: kernel: remove ARM64_CPU_SUSPEND config option arm64: make sys_call_table const arm64: Remove asm/syscalls.h arm64: Implement the compat_sys_call_table in C syscalls: Declare sys_*stat64 prototypes if __ARCH_WANT_(COMPAT_)STAT64 compat: Declare compat_sys_sigpending and compat_sys_sigprocmask prototypes arm64: uapi: expose our struct ucontext to the uapi headers smp, ARM64: Kill SMP single function call interrupt arm64: Emulate SETEND for AArch32 tasks arm64: Consolidate hotplug notifier for instruction emulation arm64: Track system support for mixed endian EL0 arm64: implement generic IOMMU configuration arm64: Combine coherent and non-coherent swiotlb dma_ops ...
2015-01-29Merge tag 'efi-next' of ↵Ingo Molnar1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/efi Pull EFI updates from Matt Fleming: " - Move efivarfs from the misc filesystem section to pseudo filesystem, since that's a more logical and accurate place - Leif Lindholm - Update efibootmgr URL in Kconfig help - Peter Jones - Improve accuracy of EFI guid function names - Borislav Petkov - Expose firmware platform size in sysfs for the benefit of EFI boot loader installers and other utilities - Steve McIntyre - Cleanup __init annotations for arm64/efi code - Ard Biesheuvel - Mark the UIE as unsupported for rtc-efi - Ard Biesheuvel - Fix memory leak in error code path of runtime map code - Dan Carpenter - Improve robustness of get_memory_map() by removing assumptions on the size of efi_memory_desc_t (which could change in future spec versions) and querying the firmware instead of guessing about the memmap size - Ard Biesheuvel - Remove superfluous guid unparse calls - Ivan Khoronzhuk - Delete unnecessary chosen@0 DT node FDT code since was duplicated from code in drivers/of and is entirely unnecessary - Leif Lindholm There's nothing super scary, mainly cleanups, and a merge from Ricardo who kindly picked up some patches from the linux-efi mailing list while I was out on annual leave in December. Perhaps the biggest risk is the get_memory_map() change from Ard, which changes the way that both the arm64 and x86 EFI boot stub build the early memory map. It would be good to have it bake in linux-next for a while. " Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-15arm64/efi: efistub: Apply __init annotationArd Biesheuvel1-4/+4
This ensures all stub component are freed when the kernel proper is done booting, by prefixing the names of all ELF sections that have the SHF_ALLOC attribute with ".init". This approach ensures that even implicitly emitted allocated data (like initializer values and string literals) are covered. At the same time, remove some __init annotations in the stub that have now become redundant, and add the __init annotation to handle_kernel_image which will now trigger a section mismatch warning without it. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-01-12arm64/efi: move SetVirtualAddressMap() to UEFI stubArd Biesheuvel1-0/+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>
2014-11-05efi: efi-stub: notify on DTB absenceMark Rutland1-1/+10
In the absence of a DTB configuration table, the EFI stub will happily continue attempting to boot a kernel, despite the fact that this kernel may not function without a description of the hardware. In this case, as with a typo'd "dtb=" option (e.g. "dbt=") or many other possible failures, the only output seen by the user will be the rather terse output from the EFI stub: EFI stub: Booting Linux Kernel... To aid those attempting to debug such failures, this patch adds a notice when no DTB is found, making the output more helpful: EFI stub: Booting Linux Kernel... EFI stub: Generating empty DTB Additionally, a positive acknowledgement is added when a user-specified DTB is in use: EFI stub: Booting Linux Kernel... EFI stub: Using DTB from command line Similarly, a positive acknowledgement is added when a DTB from a configuration table is in use: EFI stub: Booting Linux Kernel... EFI stub: Using DTB from configuration table Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Roy Franz <roy.franz@linaro.org> Acked-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-10-03efi: Add efi= parameter parsing to the EFI boot stubMatt Fleming1-0/+4
We need a way to customize the behaviour of the EFI boot stub, in particular, we need a way to disable the "chunking" workaround, used when reading files from the EFI System Partition. One of my machines doesn't cope well when reading files in 1MB chunks to a buffer above the 4GB mark - it appears that the "chunking" bug workaround triggers another firmware bug. This was only discovered with commit 4bf7111f5016 ("x86/efi: Support initrd loaded above 4G"), and that commit is perfectly valid. The symptom I observed was a corrupt initrd rather than any kind of crash. efi= is now used to specify EFI parameters in two very different execution environments, the EFI boot stub and during kernel boot. There is also a slight performance optimization by enabling efi=nochunk, but that's offset by the fact that you're more likely to run into firmware issues, at least on x86. This is the rationale behind leaving the workaround enabled by default. Also provide some documentation for EFI_READ_CHUNK_SIZE and why we're using the current value of 1MB. Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Roy Franz <roy.franz@linaro.org> Cc: Maarten Lankhorst <m.b.lankhorst@gmail.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-07-18efi: efistub: Convert into static libraryArd Biesheuvel1-0/+284
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>