kernel/drivers/firmware/efi/runtime-wrappers.c, branch linux-5.1.y

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2019-03-10T17:17:23Z

Pull arm64 updates from Catalin Marinas: - Pseudo NMI support for arm64 using GICv3 interrupt priorities - uaccess macros clean-up (unsafe user accessors also merged but reverted, waiting for objtool support on arm64) - ptrace regsets for Pointer Authentication (ARMv8.3) key management - inX() ordering w.r.t. delay() on arm64 and riscv (acks in place by the riscv maintainers) - arm64/perf updates: PMU bindings converted to json-schema, unused variable and misleading comment removed - arm64/debug fixes to ensure checking of the triggering exception level and to avoid the propagation of the UNKNOWN FAR value into the si_code for debug signals - Workaround for Fujitsu A64FX erratum 010001 - lib/raid6 ARM NEON optimisations - NR_CPUS now defaults to 256 on arm64 - Minor clean-ups (documentation/comments, Kconfig warning, unused asm-offsets, clang warnings) - MAINTAINERS update for list information to the ARM64 ACPI entry * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (54 commits) arm64: mmu: drop paging_init comments arm64: debug: Ensure debug handlers check triggering exception level arm64: debug: Don't propagate UNKNOWN FAR into si_code for debug signals Revert "arm64: uaccess: Implement unsafe accessors" arm64: avoid clang warning about self-assignment arm64: Kconfig.platforms: fix warning unmet direct dependencies lib/raid6: arm: optimize away a mask operation in NEON recovery routine lib/raid6: use vdupq_n_u8 to avoid endianness warnings arm64: io: Hook up __io_par() for inX() ordering riscv: io: Update __io_[p]ar() macros to take an argument asm-generic/io: Pass result of I/O accessor to __io_[p]ar() arm64: Add workaround for Fujitsu A64FX erratum 010001 arm64: Rename get_thread_info() arm64: Remove documentation about TIF_USEDFPU arm64: irqflags: Fix clang build warnings arm64: Enable the support of pseudo-NMIs arm64: Skip irqflags tracing for NMI in IRQs disabled context arm64: Skip preemption when exiting an NMI arm64: Handle serror in NMI context irqchip/gic-v3: Allow interrupts to be set as pseudo-NMI ...

Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-03-06T15:13:56Z

Pull EFI updates from Ingo Molnar: "The main EFI changes in this cycle were: - Use 32-bit alignment for efi_guid_t - Allow the SetVirtualAddressMap() call to be omitted - Implement earlycon=efifb based on existing earlyprintk code - Various minor fixes and code cleanups from Sai, Ard and me" * 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: Fix build error due to enum collision between efi.h and ima.h efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation x86: Make ARCH_USE_MEMREMAP_PROT a generic Kconfig symbol efi/arm/arm64: Allow SetVirtualAddressMap() to be omitted efi: Replace GPL license boilerplate with SPDX headers efi/fdt: Apply more cleanups efi: Use 32-bit alignment for efi_guid_t efi/memattr: Don't bail on zero VA if it equals the region's PA x86/efi: Mark can_free_region() as an __init function

efi: Fix build error due to enum collision between efi.h and ima.h

2019-02-16T11:18:55Z

The following commit: a893ea15d764 ("tpm: move tpm_chip definition to include/linux/tpm.h") introduced a build error when both IMA and EFI are enabled: In file included from ../security/integrity/ima/ima_fs.c:30: ../security/integrity/ima/ima.h:176:7: error: redeclaration of enumerator "NONE" What happens is that both headers (ima.h and efi.h) defines the same 'NONE' constant, and it broke when they started getting included from the same file: Rework to prefix the EFI enum with 'EFI_*'. Signed-off-by: Anders Roxell Signed-off-by: Ard Biesheuvel Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20190215165551.12220-2-ard.biesheuvel@linaro.org [ Cleaned up the changelog a bit. ] Signed-off-by: Ingo Molnar

x86/platform/UV: Use efi_runtime_lock to serialise BIOS calls

2019-02-15T14:19:56Z

Calls into UV firmware must be protected against concurrency, expose the efi_runtime_lock to the UV platform, and use it to serialise UV BIOS calls. Signed-off-by: Hedi Berriche Signed-off-by: Borislav Petkov Reviewed-by: Ard Biesheuvel Reviewed-by: Russ Anderson Reviewed-by: Dimitri Sivanich Reviewed-by: Mike Travis Cc: Andy Shevchenko Cc: Bhupesh Sharma Cc: Darren Hart Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: linux-efi Cc: platform-driver-x86@vger.kernel.org Cc: stable@vger.kernel.org # v4.9+ Cc: Steve Wahl Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20190213193413.25560-5-hedi.berriche@hpe.com

efi: Let architectures decide the flags that should be saved/restored

2019-02-06T10:05:19Z

Currently, irqflags are saved before calling runtime services and checked for mismatch on return. Provide a pair of overridable macros to save and restore (if needed) the state that need to be preserved on return from a runtime service. This allows to check for flags that are not necesarly related to irqflags. Signed-off-by: Julien Thierry Acked-by: Catalin Marinas Acked-by: Ard Biesheuvel Acked-by: Marc Zyngier Cc: Ard Biesheuvel Cc: linux-efi@vger.kernel.org Signed-off-by: Catalin Marinas

efi: Fix debugobjects warning on 'efi_rts_work'

2018-11-15T09:04:45Z

The following commit: 9dbbedaa6171 ("efi: Make efi_rts_work accessible to efi page fault handler") converted 'efi_rts_work' from an auto variable to a global variable. However, when submitting the work, INIT_WORK_ONSTACK() was still used, causing the following complaint from debugobjects: ODEBUG: object 00000000ed27b500 is NOT on stack 00000000c7d38760, but annotated. Change the macro to just INIT_WORK() to eliminate the warning. Signed-off-by: Waiman Long Signed-off-by: Ard Biesheuvel Acked-by: Sai Praneeth Prakhya Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Fixes: 9dbbedaa6171 ("efi: Make efi_rts_work accessible to efi page fault handler") Link: http://lkml.kernel.org/r/20181114175544.12860-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar

efi/x86: Handle page faults occurring while running EFI runtime services

2018-09-26T10:14:55Z

Memory accesses performed by UEFI runtime services should be limited to: - reading/executing from EFI_RUNTIME_SERVICES_CODE memory regions - reading/writing from/to EFI_RUNTIME_SERVICES_DATA memory regions - reading/writing by-ref arguments - reading/writing from/to the stack. Accesses outside these regions may cause the kernel to hang because the memory region requested by the firmware isn't mapped in efi_pgd, which causes a page fault in ring 0 and the kernel fails to handle it, leading to die(). To save kernel from hanging, add an EFI specific page fault handler which recovers from such faults by 1. If the efi runtime service is efi_reset_system(), reboot the machine through BIOS. 2. If the efi runtime service is _not_ efi_reset_system(), then freeze efi_rts_wq and schedule a new process. The EFI page fault handler offers us two advantages: 1. Avoid potential hangs caused by buggy firmware. 2. Shout loud that the firmware is buggy and hence is not a kernel bug. Tested-by: Bhupesh Sharma Suggested-by: Matt Fleming Based-on-code-from: Ricardo Neri Signed-off-by: Sai Praneeth Prakhya Reviewed-by: Thomas Gleixner [ardb: clarify commit log] Signed-off-by: Ard Biesheuvel

efi: Make efi_rts_work accessible to efi page fault handler

2018-09-26T10:14:50Z

After the kernel has booted, if any accesses by firmware causes a page fault, the efi page fault handler would freeze efi_rts_wq and schedules a new process. To do this, the efi page fault handler needs efi_rts_work. Hence, make it accessible. There will be no race conditions in accessing this structure, because all the calls to efi runtime services are already serialized. Tested-by: Bhupesh Sharma Suggested-by: Matt Fleming Based-on-code-from: Ricardo Neri Signed-off-by: Sai Praneeth Prakhya Signed-off-by: Ard Biesheuvel

efi: Use a work queue to invoke EFI Runtime Services

2018-07-15T22:43:12Z

Presently, when a user process requests the kernel to execute any UEFI runtime service, the kernel temporarily switches to a separate set of page tables that describe the virtual mapping of the UEFI runtime services regions in memory. Since UEFI runtime services are typically invoked with interrupts enabled, any code that may be called during this time, will have an incorrect view of the process's address space. Although it is unusual for code running in interrupt context to make assumptions about the process context it runs in, there are cases (such as the perf subsystem taking samples) where this causes problems. So let's set up a work queue for calling UEFI runtime services, so that the actual calls are made when the work queue items are dispatched by a work queue worker running in a separate kernel thread. Such threads are not expected to have userland mappings in the first place, and so the additional mappings created for the UEFI runtime services can never clash with any. The ResetSystem() runtime service is not covered by the work queue handling, since it is not expected to return, and may be called at a time when the kernel is torn down to the point where we cannot expect work queues to still be operational. The non-blocking variants of SetVariable() and QueryVariableInfo() are also excluded: these are intended to be used from atomic context, which obviously rules out waiting for a completion to be signalled by another thread. Note that these variants are currently only used for UEFI runtime services calls that occur very early in the boot, and for ones that occur in critical conditions, e.g., to flush kernel logs to UEFI variables via efi-pstore. Suggested-by: Andy Lutomirski Signed-off-by: Sai Praneeth Prakhya [ardb: exclude ResetSystem() from the workqueue treatment merge from 2 separate patches and rewrite commit log] Signed-off-by: Ard Biesheuvel Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180711094040.12506-4-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar

efi: Replace runtime services spinlock with semaphore

2016-09-09T15:08:43Z

The purpose of the efi_runtime_lock is to prevent concurrent calls into the firmware. There is no need to use spinlocks here, as long as we ensure that runtime service invocations from an atomic context (i.e., EFI pstore) cannot block. So use a semaphore instead, and use down_trylock() in the nonblocking case. We don't use a mutex here because the mutex_trylock() function must not be called from interrupt context, whereas the down_trylock() can. Signed-off-by: Ard Biesheuvel Cc: Leif Lindholm Cc: Mark Rutland Cc: Sylvain Chouleur Signed-off-by: Matt Fleming