- 27 6月, 2016 1 次提交
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由 Alex Thorlton 提交于
This commit makes a few slight modifications to the efi_call_virt() macro to get it to work with function pointers that are stored in locations other than efi.systab->runtime, and renames the macro to efi_call_virt_pointer(). The majority of the changes here are to pull these macros up into header files so that they can be accessed from outside of drivers/firmware/efi/runtime-wrappers.c. The most significant change not directly related to the code move is to add an extra "p" argument into the appropriate efi_call macros, and use that new argument in place of the, formerly hard-coded, efi.systab->runtime pointer. The last piece of the puzzle was to add an efi_call_virt() macro back into drivers/firmware/efi/runtime-wrappers.c to wrap around the new efi_call_virt_pointer() macro - this was mainly to keep the code from looking too cluttered by adding a bunch of extra references to efi.systab->runtime everywhere. Note that I also broke up the code in the efi_call_virt_pointer() macro a bit in the process of moving it. Signed-off-by: NAlex Thorlton <athorlton@sgi.com> Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roy Franz <roy.franz@linaro.org> Cc: Russ Anderson <rja@sgi.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1466839230-12781-5-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 28 4月, 2016 4 次提交
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由 Mark Rutland 提交于
Now that arm, arm64, and x86 all provide ARCH_EFI_IRQ_FLAGS_MASK, we can get rid of the trivial and now unused implementation of efi_call_virt_check_flags(). Signed-off-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> 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/1461614832-17633-41-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Mark Rutland 提交于
The UEFI spec allows runtime services to be called with interrupts masked or unmasked, and if a runtime service function needs to mask interrupts, it must restore the mask to its original state before returning (i.e. from the PoV of the OS, this does not change across a call). Firmware should never unmask exceptions, as these may then be taken by the OS unexpectedly. Unfortunately, some firmware has been seen to unmask IRQs (and potentially other maskable exceptions) across runtime services calls, leaving IRQ flags corrupted after returning from a runtime services function call. This may be detected by the IRQ tracing code, but often goes unnoticed, leaving a potentially disastrous bug hidden. This patch detects when the IRQ flags are corrupted by an EFI runtime services call, logging the call and specific corruption to the console. While restoring the expected value of the flags is insufficient to avoid problems, we do so to avoid redundant warnings from elsewhere (e.g. IRQ tracing). The set of bits in flags which we want to check is architecture-specific (e.g. we want to check FIQ on arm64, but not the zero flag on x86), so each arch must provide ARCH_EFI_IRQ_FLAGS_MASK to describe those. In the absence of this mask, the check is a no-op, and we redundantly save the flags twice, but that will be short-lived as subsequent patches will implement this and remove the scaffolding. Signed-off-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Russell King <linux@arm.linux.org.uk> 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/1461614832-17633-37-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Mark Rutland 提交于
Now that all users of the EFI runtime wrappers (arm,arm64,x86) have been migrated to the new setup/teardown macros, we don't need to support overridden {__,}efi_call_virt() implementations. This patch removes the unnecessary #ifdefs. Signed-off-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> 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/1461614832-17633-36-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Mark Rutland 提交于
Currently each architecture must implement two macros, efi_call_virt() and __efi_call_virt(), which only differ by the presence or absence of a return type. Otherwise, the logic surrounding the call is identical. As each architecture must define the entire body of each, we can't place any generic manipulation (e.g. irq flag validation) in the middle. This patch adds template implementations of these macros. With these, arch code can implement three template macros, avoiding reptition for the void/non-void return cases: * arch_efi_call_virt_setup() Sets up the environment for the call (e.g. switching page tables, allowing kernel-mode use of floating point, if required). * arch_efi_call_virt() Performs the call. The last expression in the macro must be the call itself, allowing the logic to be shared by the void and non-void cases. * arch_efi_call_virt_teardown() Restores the usual kernel environment once the call has returned. While the savings from repition are minimal, we additionally gain the ability to add common code around the call with the call environment set up. This can be used to detect common firmware issues (e.g. bad irq mask management). Signed-off-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk> Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> 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/1461614832-17633-32-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 22 2月, 2016 1 次提交
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由 Ard Biesheuvel 提交于
The UEFI spec allows Runtime Services to be invoked with interrupts enabled. The only reason we were disabling interrupts was to prevent recursive calls into the services on the same CPU, which will lead to deadlock. However, the only context where such invocations may occur legally is from efi-pstore via efivars, and that code has been updated to call a non-blocking alternative when invoked from a non-interruptible context. So instead, update the ordinary, blocking UEFI Runtime Services wrappers to execute with interrupts enabled. This aims to prevent excessive interrupt latencies on uniprocessor platforms with slow variable stores. Note that other OSes such as Windows call UEFI Runtime Services with interrupts enabled as well. Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> 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/1455712566-16727-3-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 03 2月, 2016 3 次提交
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由 Ard Biesheuvel 提交于
The rtc_lock spinlock aims to serialize access to the CMOS RTC between the UEFI firmware and the kernel drivers that use it directly. However, x86 is the only arch that performs such direct accesses, and that never uses the time related UEFI runtime services. Since no other UEFI enlightened architectures have a legcay CMOS RTC anyway, we can remove the rtc_lock spinlock entirely. Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.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/1454364428-494-7-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Ard Biesheuvel 提交于
This code is long gone, so remove the comment as well. Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.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/1454364428-494-6-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Ard Biesheuvel 提交于
This introduces a new runtime wrapper for the QueryVariableInfo() UEFI Runtime Service, which gives up immediately rather than spins on failure to grab the efi_runtime spinlock. This is required in the non-blocking path of the efi-pstore code. Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.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/1454364428-494-4-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 04 10月, 2014 3 次提交
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由 Matt Fleming 提交于
commit 5dc3826d9f08 ("efi: Implement mandatory locking for UEFI Runtime Services") implemented some conditional locking when accessing variable runtime services that Ingo described as "pretty disgusting". The intention with the !efi_in_nmi() checks was to avoid live-locks when trying to write pstore crash data into an EFI variable. Such lockless accesses are allowed according to the UEFI specification when we're in a "non-recoverable" state, but whether or not things are implemented correctly in actual firmware implementations remains an unanswered question, and so it would seem sensible to avoid doing any kind of unsynchronized variable accesses. Furthermore, the efi_in_nmi() tests are inadequate because they don't account for the case where we call EFI variable services from panic or oops callbacks and aren't executing in NMI context. In other words, live-locking is still possible. Let's just remove the conditional locking altogether. Now we've got the ->set_variable_nonblocking() EFI variable operation we can abort if the runtime lock is already held. Aborting is by far the safest option. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
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由 Matt Fleming 提交于
There are some circumstances that call for trying to write an EFI variable in a non-blocking way. One such scenario is when writing pstore data in efi_pstore_write() via the pstore_dump() kdump callback. Now that we have an EFI runtime spinlock we need a way of aborting if there is contention instead of spinning, since when writing pstore data from the kdump callback, the runtime lock may already be held by the CPU that's running the callback if we crashed in the middle of an EFI variable operation. The situation is sufficiently special that a new EFI variable operation is warranted. Introduce ->set_variable_nonblocking() for this use case. It is an optional EFI backend operation, and need only be implemented by those backends that usually acquire locks to serialize access to EFI variables, as is the case for virt_efi_set_variable() where we now grab the EFI runtime spinlock. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
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由 Ard Biesheuvel 提交于
According to section 7.1 of the UEFI spec, Runtime Services are not fully reentrant, and there are particular combinations of calls that need to be serialized. Use a spinlock to serialize all Runtime Services with respect to all others, even if this is more than strictly needed. We've managed to get away without requiring a runtime services lock until now because most of the interactions with EFI involve EFI variables, and those operations are already serialised with __efivars->lock. Some of the assumptions underlying the decision whether locks are needed or not (e.g., SetVariable() against ResetSystem()) may not apply universally to all [new] architectures that implement UEFI. Rather than try to reason our way out of this, let's just implement at least what the spec requires in terms of locking. Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
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- 08 7月, 2014 1 次提交
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由 Ard Biesheuvel 提交于
In order for other archs (such as arm64) to be able to reuse the virtual mode function call wrappers, move them to drivers/firmware/efi/runtime-wrappers.c. Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
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