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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2014-08-04 18:16:00 +0200 |
|---|---|---|
| committer | Matt Fleming <matt.fleming@intel.com> | 2014-10-03 19:40:57 +0200 |
| commit | 161485e8273001e56b2f20755ad9b6217b601fb3 (patch) | |
| tree | 3e99e9f4a6515c0382c7ccb3e7a3888382f4c3b3 /arch/x86 | |
| parent | Linux 3.17-rc1 (diff) | |
| download | linux-161485e8273001e56b2f20755ad9b6217b601fb3.tar.xz linux-161485e8273001e56b2f20755ad9b6217b601fb3.zip | |
efi: Implement mandatory locking for UEFI Runtime Services
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: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/efi.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 044a2fd3c5fe..b39ee5f2c02d 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -86,6 +86,8 @@ extern void __iomem *efi_ioremap(unsigned long addr, unsigned long size, #endif /* CONFIG_X86_32 */ +#define efi_in_nmi() in_nmi() + extern int add_efi_memmap; extern struct efi_scratch efi_scratch; extern void efi_set_executable(efi_memory_desc_t *md, bool executable); |