From b2203a9bf53237368a7c7fc976c9616b5562af8e Mon Sep 17 00:00:00 2001 From: "Vishal Moola (Oracle)" Date: Tue, 3 Mar 2026 11:48:26 -0800 Subject: [PATCH] x86/mm/pat: Convert populate_pgd() to use page table apis Use the ptdesc APIs for all page table allocation and free sites to allow their separate allocation from struct page in the future. Convert the remaining get_zeroed_page() calls to the generic page table APIs, as they already use ptdescs. Pass through init_mm since these are kernel page tables, as both functions require it to identify kernel page tables. Because the generic implementations do not use the second argument, pass a placeholder to avoid reimplementing them or risking breakage on other architectures. It is not obvious whether these pages are freed. Regardless, convert the remaining free paths as needed, noting that the only other possible free paths have already been converted and that a frozen page table test kernel has not reported any issues. Signed-off-by: Vishal Moola (Oracle) Signed-off-by: Dave Hansen Acked-by: Mike Rapoport (Microsoft) Link: https://patch.msgid.link/20260303194828.1406905-4-vishal.moola@gmail.com --- arch/x86/mm/pat/set_memory.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index 72a260007996..17c1c28e3491 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -1747,7 +1747,11 @@ static int populate_pgd(struct cpa_data *cpa, unsigned long addr) pgd_entry = cpa->pgd + pgd_index(addr); if (pgd_none(*pgd_entry)) { - p4d = (p4d_t *)get_zeroed_page(GFP_KERNEL); + /* + * Pass 0 as a placeholder for the second argument, since the + * generic implementation of p4d_alloc_one() does not use it. + */ + p4d = p4d_alloc_one(&init_mm, 0); if (!p4d) return -1; @@ -1759,7 +1763,11 @@ static int populate_pgd(struct cpa_data *cpa, unsigned long addr) */ p4d = p4d_offset(pgd_entry, addr); if (p4d_none(*p4d)) { - pud = (pud_t *)get_zeroed_page(GFP_KERNEL); + /* + * Pass 0 as a placeholder for the second argument, since the + * generic implementation of pud_alloc_one() does not use it. + */ + pud = pud_alloc_one(&init_mm, 0); if (!pud) return -1;