Ard Biesheuvel c8f325a59c efi/fdt: Avoid FDT manipulation after ExitBootServices() ... Some AArch64 UEFI implementations disable the MMU in ExitBootServices(), after which unaligned accesses to RAM are no longer supported. Commit: abfb7b686a ("efi/libstub/arm*: Pass latest memory map to the kernel") fixed an issue in the memory map handling of the stub FDT code, but inadvertently created an issue with such firmware, by moving some of the FDT manipulation to after the invocation of ExitBootServices(). Given that the stub's libfdt implementation uses the ordinary, accelerated string functions, which rely on hardware handling of unaligned accesses, manipulating the FDT with the MMU off may result in alignment faults. So fix the situation by moving the update_fdt_memmap() call into the callback function invoked by efi_exit_boot_services() right before it calls the ExitBootServices() UEFI service (which is arguably a better place for it anyway) Note that disabling the MMU in ExitBootServices() is not compliant with the UEFI spec, and carries great risk due to the fact that switching from cached to uncached memory accesses halfway through compiler generated code (i.e., involving a stack) can never be done in a way that is architecturally safe. Fixes: abfb7b686a ("efi/libstub/arm*: Pass latest memory map to the kernel") Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Riku Voipio <riku.voipio@linaro.org> Cc: <stable@vger.kernel.org> Cc: mark.rutland@arm.com Cc: linux-efi@vger.kernel.org Cc: matt@codeblueprint.co.uk Cc: leif.lindholm@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>		2017-02-01 21:17:49 +01:00
..
libstub	efi/fdt: Avoid FDT manipulation after ExitBootServices()	2017-02-01 21:17:49 +01:00
test	efi/efi_test: Use memdup_user() as a cleanup	2016-10-18 17:11:19 +02:00
apple-properties.c	x86/efi: Retrieve and assign Apple device properties	2016-11-13 08:23:16 +01:00
arm-init.c	efi/arm*: Fix efi_init() error handling	2016-10-18 17:11:17 +02:00
arm-runtime.c	arm64: dump: Make ptdump debugfs a separate option	2016-11-07 18:15:04 +00:00
capsule-loader.c
capsule.c
cper.c
dev-path-parser.c	efi: Add device path parser	2016-11-13 08:23:15 +01:00
efi-pstore.c	Fix bug in module unloading.	2016-10-06 15:16:16 -07:00
efi.c	efi: Add support for seeding the RNG from a UEFI config table	2016-11-13 08:23:14 +01:00
efibc.c
efivars.c	efi: Don't use spinlocks for efi vars	2016-09-09 16:08:42 +01:00
esrt.c	efi/esrt: Use memremap not ioremap to access ESRT table in memory	2016-09-09 16:08:39 +01:00
fake_mem.c	x86/efi: Don't allocate memmap through memblock after mm_init()	2017-01-07 08:58:07 +01:00
Kconfig	x86/efi: Retrieve and assign Apple device properties	2016-11-13 08:23:16 +01:00
Makefile	x86/efi: Retrieve and assign Apple device properties	2016-11-13 08:23:16 +01:00
memattr.c
memmap.c	x86/efi: Don't allocate memmap through memblock after mm_init()	2017-01-07 08:58:07 +01:00
reboot.c
runtime-map.c
runtime-wrappers.c	efi: Replace runtime services spinlock with semaphore	2016-09-09 16:08:43 +01:00
vars.c	efi: Don't use spinlocks for efi vars	2016-09-09 16:08:42 +01:00