kernel/drivers/firmware/efi/runtime-wrappers.c, branch linux-6.5.y

Change DEFINE_SEMAPHORE() to take a number argument

2023-04-18T18:15:24Z

Fundamentally semaphores are a counted primitive, but DEFINE_SEMAPHORE() does not expose this and explicitly creates a binary semaphore. Change DEFINE_SEMAPHORE() to take a number argument and use that in the few places that open-coded it using __SEMAPHORE_INITIALIZER(). Signed-off-by: Peter Zijlstra (Intel) [mcgrof: add some tribal knowledge about why some folks prefer binary sempahores over mutexes] Reviewed-by: Sergey Senozhatsky Reviewed-by: Davidlohr Bueso Signed-off-by: Luis Chamberlain

efi: fix userspace infinite retry read efivars after EFI runtime services page fault

2023-01-03T09:52:16Z

After [1][2], if we catch exceptions due to EFI runtime service, we will clear EFI_RUNTIME_SERVICES bit to disable EFI runtime service, then the subsequent routine which invoke the EFI runtime service should fail. But the userspace cat efivars through /sys/firmware/efi/efivars/ will stuck and infinite loop calling read() due to efivarfs_file_read() return -EINTR. The -EINTR is converted from EFI_ABORTED by efi_status_to_err(), and is an improper return value in this situation, so let virt_efi_xxx() return EFI_DEVICE_ERROR and converted to -EIO to invoker. Cc: Fixes: 3425d934fc03 ("efi/x86: Handle page faults occurring while running EFI runtime services") Fixes: 23715a26c8d8 ("arm64: efi: Recover from synchronous exceptions occurring in firmware") Signed-off-by: Ding Hui Signed-off-by: Ard Biesheuvel

arm64: efi: Recover from synchronous exceptions occurring in firmware

2022-12-08T17:33:34Z

Unlike x86, which has machinery to deal with page faults that occur during the execution of EFI runtime services, arm64 has nothing like that, and a synchronous exception raised by firmware code brings down the whole system. With more EFI based systems appearing that were not built to run Linux (such as the Windows-on-ARM laptops based on Qualcomm SOCs), as well as the introduction of PRM (platform specific firmware routines that are callable just like EFI runtime services), we are more likely to run into issues of this sort, and it is much more likely that we can identify and work around such issues if they don't bring down the system entirely. Since we already use a EFI runtime services call wrapper in assembler, we can quite easily add some code that captures the execution state at the point where the call is made, allowing us to revert to this state and proceed execution if the call triggered a synchronous exception. Given that the kernel and the firmware don't share any data structures that could end up in an indeterminate state, we can happily continue running, as long as we mark the EFI runtime services as unavailable from that point on. Signed-off-by: Ard Biesheuvel Acked-by: Catalin Marinas

efi: Change down_interruptible() in virt_efi_reset_system() to down_trylock()

2021-10-05T11:07:01Z

While reboot the system by sysrq, the following bug will be occur. BUG: sleeping function called from invalid context at kernel/locking/semaphore.c:90 in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 10052, name: rc.shutdown CPU: 3 PID: 10052 Comm: rc.shutdown Tainted: G W O 5.10.0 #1 Call trace: dump_backtrace+0x0/0x1c8 show_stack+0x18/0x28 dump_stack+0xd0/0x110 ___might_sleep+0x14c/0x160 __might_sleep+0x74/0x88 down_interruptible+0x40/0x118 virt_efi_reset_system+0x3c/0xd0 efi_reboot+0xd4/0x11c machine_restart+0x60/0x9c emergency_restart+0x1c/0x2c sysrq_handle_reboot+0x1c/0x2c __handle_sysrq+0xd0/0x194 write_sysrq_trigger+0xbc/0xe4 proc_reg_write+0xd4/0xf0 vfs_write+0xa8/0x148 ksys_write+0x6c/0xd8 __arm64_sys_write+0x18/0x28 el0_svc_common.constprop.3+0xe4/0x16c do_el0_svc+0x1c/0x2c el0_svc+0x20/0x30 el0_sync_handler+0x80/0x17c el0_sync+0x158/0x180 The reason for this problem is that irq has been disabled in machine_restart() and then it calls down_interruptible() in virt_efi_reset_system(), which would occur sleep in irq context, it is dangerous! Commit 99409b935c9a("locking/semaphore: Add might_sleep() to down_*() family") add might_sleep() in down_interruptible(), so the bug info is here. down_trylock() can solve this problem, cause there is no might_sleep. -------- Cc: Signed-off-by: Zhang Jianhua Signed-off-by: Ard Biesheuvel

efi: Add 'runtime' pointer to struct efi

2020-02-23T20:59:42Z

Instead of going through the EFI system table each time, just copy the runtime services table pointer into struct efi directly. This is the last use of the system table pointer in struct efi, allowing us to drop it in a future patch, along with a fair amount of quirky handling of the translated address. Note that usually, the runtime services pointer changes value during the call to SetVirtualAddressMap(), so grab the updated value as soon as that call returns. (Mixed mode uses a 1:1 mapping, and kexec boot enters with the updated address in the system table, so in those cases, we don't need to do anything here) Tested-by: Tony Luck # arch/ia64 Signed-off-by: Ard Biesheuvel

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428

2019-06-05T15:37:16Z

Based on 1 normalized pattern(s): this file is released under the gplv2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 68 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Armijn Hemel Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de Signed-off-by: Greg Kroah-Hartman

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