Commit 1dbf30fd authored by Juergen Gross's avatar Juergen Gross Committed by Peter Zijlstra
Browse files

x86/mm/pat: don't collapse pages without PSE set 



Collapsing pages to a leaf PMD or PUD should be done only if
X86_FEATURE_PSE is available, which is not the case when running e.g.
as a Xen PV guest.

Fixes: 41d88484 ("x86/mm/pat: restore large ROX pages after fragmentation")
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Signed-off-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250528123557.12847-3-jgross@suse.com
parent 0b3bc018

arch/x86/mm/pat/set_memory.c

+3 −0
Original line number Diff line number Diff line
@@ -1257,6 +1257,9 @@ static int collapse_pmd_page(pmd_t *pmd, unsigned long addr, 
	pgprot_t pgprot;

	int i = 0;



	if (!cpu_feature_enabled(X86_FEATURE_PSE))

		return 0;



	addr &= PMD_MASK;

	pte = pte_offset_kernel(pmd, addr);

	first = *pte;