[RFT PATCH v2 02/23] x86/boot: Disregard __supported_pte_mask in __startup_64()

Ard Biesheuvel
2025-05-04T09:53:09Z

From: Ard Biesheuvel <ardb@kernel.org>

__supported_pte_mask is statically initialized to U64_MAX and never
assigned until long after the startup code executes that creates the
initial page tables. So applying the mask is unnecessary, and can be
avoided.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/x86/boot/startup/map_kernel.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/x86/boot/startup/map_kernel.c b/arch/x86/boot/startup/map_kernel.c
index 0eac3f17dbd3..099ae2559336 100644
--- a/arch/x86/boot/startup/map_kernel.c
+++ b/arch/x86/boot/startup/map_kernel.c
@@ -179,8 +179,6 @@ unsigned long __head __startup_64(unsigned long p2v_offset,
pud[(i + 1) % PTRS_PER_PUD] = (pudval_t)pmd + pgtable_flags;

pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL;
- /* Filter out unsupported __PAGE_KERNEL_* bits: */
- pmd_entry &= __supported_pte_mask;
pmd_entry += sme_get_me_mask();
pmd_entry += physaddr;

--
2.49.0.906.g1f30a19c02-goog