[PATCH 5.15 004/244] x86/mm: Use proper mask when setting PUD mapping

Greg Kroah-Hartman
2022-08-23T10:12:28Z

From: Aaron Lu <aaron.lu@intel.com>

commit 88e0a74902f894fbbc55ad3ad2cb23b4bfba555c upstream.

Commit c164fbb40c43f("x86/mm: thread pgprot_t through
init_memory_mapping()") mistakenly used __pgprot() which doesn't respect
__default_kernel_pte_mask when setting PUD mapping.

Fix it by only setting the one bit we actually need (PSE) and leaving
the other bits (that have been properly masked) alone.

Fixes: c164fbb40c43 ("x86/mm: thread pgprot_t through init_memory_mapping()")
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/mm/init_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -646,7 +646,7 @@ phys_pud_init(pud_t *pud_page, unsigned
pages++;
spin_lock(&init_mm.page_table_lock);

- prot = __pgprot(pgprot_val(prot) | __PAGE_KERNEL_LARGE);
+ prot = __pgprot(pgprot_val(prot) | _PAGE_PSE);

set_pte_init((pte_t *)pud,
pfn_pte((paddr & PUD_MASK) >> PAGE_SHIFT,