linux/drivers/firmware/efi, branch v4.9

efi/arm: Fix absolute relocation detection for older toolchains

2016-10-19T12:49:44Z

When building the ARM kernel with CONFIG_EFI=y, the following build error may occur when using a less recent version of binutils (2.23 or older): STUBCPY drivers/firmware/efi/libstub/lib-sort.stub.o 00000000 R_ARM_ABS32 sort 00000004 R_ARM_ABS32 __ksymtab_strings drivers/firmware/efi/libstub/lib-sort.stub.o: absolute symbol references not allowed in the EFI stub (and when building with debug symbols, the list above is much longer, and contains all the internal references between the .debug sections and the actual code) This issue is caused by the fact that objcopy v2.23 or earlier does not support wildcards in its -R and -j options, which means the following line from the Makefile: STUBCOPY_FLAGS-y := -R .debug* -R *ksymtab* -R *kcrctab* fails to take effect, leaving harmless absolute relocations in the binary that are indistinguishable from relocations that may cause crashes at runtime due to the fact that these relocations are resolved at link time using the virtual address of the kernel, which is always different from the address at which the EFI firmware loads and invokes the stub. So, as a workaround, disable debug symbols explicitly when building the stub for ARM, and strip the ksymtab and kcrctab symbols for the only exported symbol we currently reuse in the stub, which is 'sort'. Tested-by: Jon Hunter Signed-off-by: Ard Biesheuvel Reviewed-by: Matt Fleming Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1476805991-7160-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar

Merge tag 'pstore-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2016-10-06T22:16:16Z

Pull pstore updates from Kees Cook: - Fix bug in module unloading - Switch to always using spinlock over cmpxchg - Explicitly define pstore backend's supported modes - Remove bounce buffer from pmsg - Switch to using memcpy_to/fromio() - Error checking improvements * tag 'pstore-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: ramoops: move spin_lock_init after kmalloc error checking pstore/ram: Use memcpy_fromio() to save old buffer pstore/ram: Use memcpy_toio instead of memcpy pstore/pmsg: drop bounce buffer pstore/ram: Set pstore flags dynamically pstore: Split pstore fragile flags pstore/core: drop cmpxchg based updates pstore/ramoops: fixup driver removal

x86/efi: Round EFI memmap reservations to EFI_PAGE_SIZE

2016-09-20T14:43:31Z

Mike Galbraith reported that his machine started rebooting during boot after, commit 8e80632fb23f ("efi/esrt: Use efi_mem_reserve() and avoid a kmalloc()") The ESRT table on his machine is 56 bytes and at no point in the efi_arch_mem_reserve() call path is that size rounded up to EFI_PAGE_SIZE, nor is the start address on an EFI_PAGE_SIZE boundary. Since the EFI memory map only deals with whole pages, inserting an EFI memory region with 56 bytes results in a new entry covering zero pages, and completely screws up the calculations for the old regions that were trimmed. Round all sizes upwards, and start addresses downwards, to the nearest EFI_PAGE_SIZE boundary. Additionally, efi_memmap_insert() expects the mem::range::end value to be one less than the end address for the region. Reported-by: Mike Galbraith Reported-by: Mike Krinkin Tested-by: Mike Krinkin Cc: Peter Jones Cc: Ard Biesheuvel Cc: Mark Rutland Cc: Taku Izumi Signed-off-by: Matt Fleming

Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into efi/core

2016-09-13T18:21:55Z

Pull EFI updates from Matt Fleming: "* Refactor the EFI memory map code into architecture neutral files and allow drivers to permanently reserve EFI boot services regions on x86, as well as ARM/arm64 - Matt Fleming * Add ARM support for the EFI esrt driver - Ard Biesheuvel * Make the EFI runtime services and efivar API interruptible by swapping spinlocks for semaphores - Sylvain Chouleur * Provide the EFI identity mapping for kexec which allows kexec to work on SGI/UV platforms with requiring the "noefi" kernel command line parameter - Alex Thorlton * Add debugfs node to dump EFI page tables on arm64 - Ard Biesheuvel * Merge the EFI test driver being carried out of tree until now in the FWTS project - Ivan Hu * Expand the list of flags for classifying EFI regions as "RAM" on arm64 so we align with the UEFI spec - Ard Biesheuvel * Optimise out the EFI mixed mode if it's unsupported (CONFIG_X86_32) or disabled (CONFIG_EFI_MIXED=n) and switch the early EFI boot services function table for direct calls, alleviating us from having to maintain the custom function table - Lukas Wunner * Miscellaneous cleanups and fixes" Signed-off-by: Ingo Molnar

efi/arm64: Treat regions with WT/WC set but WB cleared as memory

2016-09-09T15:08:54Z

Currently, memory regions are only recorded in the memblock memory table if they have the EFI_MEMORY_WB memory type attribute set. In case the region is of a reserved type, it is also marked as MEMBLOCK_NOMAP, which will leave it out of the linear mapping. However, memory regions may legally have the EFI_MEMORY_WT or EFI_MEMORY_WC attributes set, and the EFI_MEMORY_WB cleared, in which case the region in question is obviously backed by normal memory, but is not recorded in the memblock memory table at all. Since it would be useful to be able to identify any UEFI reported memory region using memblock_is_memory(), it makes sense to add all memory to the memblock memory table, and simply mark it as MEMBLOCK_NOMAP if it lacks the EFI_MEMORY_WB attribute. While implementing this, let's refactor the code slightly to make it easier to understand: replace is_normal_ram() with is_memory(), and make it return true for each region that has any of the WB|WT|WC bits set. (This follows the AArch64 bindings in the UEFI spec, which state that those are the attributes that map to normal memory) Also, replace is_reserve_region() with is_usable_memory(), and only invoke it if the region in question was identified as memory by is_memory() in the first place. The net result is the same (only reserved regions that are backed by memory end up in the memblock memory table with the MEMBLOCK_NOMAP flag set) but carried out in a more straightforward way. Finally, we remove the trailing asterisk in the EFI debug output. Keeping it clutters the code, and it serves no real purpose now that we no longer temporarily reserve BootServices code and data regions like we did in the early days of EFI support on arm64 Linux (which it inherited from the x86 implementation) Signed-off-by: Ard Biesheuvel Reviewed-by: Leif Lindholm Tested-by: James Morse Reviewed-by: James Morse Signed-off-by: Matt Fleming

efi: Add efi_test driver for exporting UEFI runtime service interfaces

2016-09-09T15:08:53Z

This driver is used by the Firmware Test Suite (FWTS) for testing the UEFI runtime interfaces readiness of the firmware. This driver exports UEFI runtime service interfaces into userspace, which allows to use and test UEFI runtime services provided by the firmware. This driver uses the efi. function pointers directly instead of going through the efivar API to allow for direct testing of the UEFI runtime service interfaces provided by the firmware. Details for FWTS are available from, Signed-off-by: Ivan Hu Cc: joeyli Cc: Ricardo Neri Cc: Ard Biesheuvel Signed-off-by: Matt Fleming

efi/arm64: Add debugfs node to dump UEFI runtime page tables

2016-09-09T15:08:51Z

Register the debugfs node 'efi_page_tables' to allow the UEFI runtime page tables to be inspected. Note that ARM does not have 'asm/ptdump.h' [yet] so for now, this is arm64 only. Signed-off-by: Ard Biesheuvel Acked-by: Mark Rutland Cc: Leif Lindholm Signed-off-by: Matt Fleming

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

efi: Don't use spinlocks for efi vars

2016-09-09T15:08:42Z

All efivars operations are protected by a spinlock which prevents interruptions and preemption. This is too restricted, we just need a lock preventing concurrency. The idea is to use a semaphore of count 1 and to have two ways of locking, depending on the context: - In interrupt context, we call down_trylock(), if it fails we return an error - In normal context, we call down_interruptible() 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: Sylvain Chouleur Signed-off-by: Ard Biesheuvel Cc: Leif Lindholm Cc: Mark Rutland Cc: Sylvain Chouleur Signed-off-by: Matt Fleming

efi: Use a file local lock for efivars

2016-09-09T15:08:41Z

This patch replaces the spinlock in the efivars struct with a single lock for the whole vars.c file. The goal of this lock is to protect concurrent calls to efi variable services, registering and unregistering. This allows us to register new efivars operations without having in-progress call. Signed-off-by: Sylvain Chouleur Signed-off-by: Ard Biesheuvel Cc: Leif Lindholm Cc: Mark Rutland Cc: Sylvain Chouleur Signed-off-by: Matt Fleming