If either the eXecute Disable (XD) bit is set to disabled in uEFI
firmware or noexec=off option is given as kernel boot parameter, the
system comes up with the error message
Error ident-mapping new memmap (0x13b0ac000)!
and EFI runtime service is unavailable.
This is because kernel_map_pages_in_pgd() checks __supported_pte_mask
and returns an error if _PAGE_NX is not available. As a result,
efi_setup_page_tables() prints the error message and
__efi_enter_virtual_mode() clears the EFI_RUNTIME_SERVICES bit in
efi.flags.
This patch changes kernel_map_pages_in_pgd() to set up the pte without
_PAGE_NX if the nx capability is unavailable instead of returning an
error.
Signed-off-by: Kosuke Tatsukawa <[email protected]>
---
arch/x86/mm/pageattr.c | 6 +-----
1 files changed, 1 insertions(+), 5 deletions(-)
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index a3137a4..3417c26 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -1951,10 +1951,7 @@ int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address,
.flags = 0,
};
- if (!(__supported_pte_mask & _PAGE_NX))
- goto out;
-
- if (!(page_flags & _PAGE_NX))
+ if ((__supported_pte_mask & _PAGE_NX) && !(page_flags & _PAGE_NX))
cpa.mask_clr = __pgprot(_PAGE_NX);
cpa.mask_set = __pgprot(_PAGE_PRESENT | page_flags);
@@ -1962,7 +1959,6 @@ int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address,
retval = __change_page_attr_set_clr(&cpa, 0);
__flush_tlb_all();
-out:
return retval;
}