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commit de53c3786a3ce162a1c815d0c04c766c23ec9c0a upstream. EFI_OLD_MEMMAP's efi_call_phys_prolog() calls set_pgd() with swapper PGD that has PAGE_USER set, which makes PTI set NX on it, and therefore EFI can't execute it's code. Fix that by forcefully clearing _PAGE_NX from the PGD (this can't be done by the pgprot API). _PAGE_NX will be automatically reintroduced in efi_call_phys_epilog(), as _set_pgd() will again notice that this is _PAGE_USER, and set _PAGE_NX on it. Tested-by: Dimitri Sivanich <sivanich@hpe.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/nycvar.YFH.7.76.1801052215460.11852@cbobk.fhfr.pm Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.