linux_dsm_epyc7002/arch/x86/platform/efi
Ard Biesheuvel ca0e30dcaa efi: Add nonblocking option to efi_query_variable_store()
The function efi_query_variable_store() may be invoked by
efivar_entry_set_nonblocking(), which itself takes care to only
call a non-blocking version of the SetVariable() runtime
wrapper. However, efi_query_variable_store() may call the
SetVariable() wrapper directly, as well as the wrapper for
QueryVariableInfo(), both of which could deadlock in the same
way we are trying to prevent by calling
efivar_entry_set_nonblocking() in the first place.

So instead, modify efi_query_variable_store() to use the
non-blocking variants of QueryVariableInfo() (and give up rather
than free up space if the available space is below
EFI_MIN_RESERVE) if invoked with the 'nonblocking' argument set
to true.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt 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/1454364428-494-5-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-03 11:31:04 +01:00
..
early_printk.c x86/efi: earlyprintk=efi,keep fix 2014-05-03 06:39:06 +01:00
efi_32.c x86/efi: Build our own page table structures 2015-11-29 09:15:42 +01:00
efi_64.c * We don't need to carry our own formatting code in the esrt driver 2015-12-19 21:24:52 +01:00
efi_stub_32.S x86/efi: Mark initialization code as such 2014-10-03 18:41:03 +01:00
efi_stub_64.S x86/efi: Hoist page table switching code into efi_call_virt() 2015-11-29 09:15:42 +01:00
efi_thunk_64.S x86/efi: Avoid triple faults during EFI mixed mode calls 2015-02-13 15:42:56 +00:00
efi-bgrt.c x86/efi-bgrt: Replace early_memremap() with memremap() 2016-01-06 18:28:52 +01:00
efi.c x86/efi: Setup separate EFI page tables in kexec paths 2016-01-21 21:01:34 +01:00
Makefile x86/efi: Move all workarounds to a separate file quirks.c 2014-06-19 11:14:33 +01:00
quirks.c efi: Add nonblocking option to efi_query_variable_store() 2016-02-03 11:31:04 +01:00