[PATCHv7 07/16] x86/mm: Return correct level from lookup_address() if pte is none
From: Kirill A. Shutemov <hidden>
Date: 2024-02-12 10:45:06
Also in:
lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 mm · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
lookup_address() only returns correct page table level for the entry if the entry is not none. Make the helper to always return correct 'level'. It allows to implement iterator over kernel page tables using lookup_address(). Add one more entry into enum pg_level to indicate size of VA covered by one PGD entry in 5-level paging mode. Signed-off-by: Kirill A. Shutemov <redacted> Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com> --- arch/x86/include/asm/pgtable_types.h | 1 + arch/x86/mm/pat/set_memory.c | 8 ++++---- 2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 0b748ee16b3d..3f648ffdfbe5 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h@@ -548,6 +548,7 @@ enum pg_level { PG_LEVEL_2M, PG_LEVEL_1G, PG_LEVEL_512G, + PG_LEVEL_256T, PG_LEVEL_NUM };
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index f92da8c9a86d..3612e3167147 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c@@ -666,32 +666,32 @@ pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address, pud_t *pud; pmd_t *pmd; - *level = PG_LEVEL_NONE; + *level = PG_LEVEL_256T; if (pgd_none(*pgd)) return NULL; + *level = PG_LEVEL_512G; p4d = p4d_offset(pgd, address); if (p4d_none(*p4d)) return NULL; - *level = PG_LEVEL_512G; if (p4d_large(*p4d) || !p4d_present(*p4d)) return (pte_t *)p4d; + *level = PG_LEVEL_1G; pud = pud_offset(p4d, address); if (pud_none(*pud)) return NULL; - *level = PG_LEVEL_1G; if (pud_large(*pud) || !pud_present(*pud)) return (pte_t *)pud; + *level = PG_LEVEL_2M; pmd = pmd_offset(pud, address); if (pmd_none(*pmd)) return NULL; - *level = PG_LEVEL_2M; if (pmd_large(*pmd) || !pmd_present(*pmd)) return (pte_t *)pmd;
--
2.43.0