Commit 9c006972c3fe removes the pxd_present() checks because the caller checks pxd_present(). But, in case of vmap_try_huge_pud(), the caller only checks pud_present(); pud_free_pmd_page() recurses on each pmd through pmd_free_pte_page(), wherein the pmd may be none. Thus it is possible to hit a warning in the latter, since pmd_none => !pmd_table(). Thus, enforce these checks again through pxd_leaf(). This problem was found by code inspection. The patch is based on 6.15-rc6.
Fixes: 9c006972c3fe (arm64: mmu: drop pXd_present() checks from pXd_free_pYd_table()) Cc: stable@vger.kernel.org Reported-by: Ryan Roberts ryan.roberts@arm.com Signed-off-by: Dev Jain dev.jain@arm.com --- arch/arm64/mm/mmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index ea6695d53fb9..3d6789413a9b 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1255,7 +1255,7 @@ int pmd_free_pte_page(pmd_t *pmdp, unsigned long addr)
pmd = READ_ONCE(*pmdp);
- if (!pmd_table(pmd)) { + if (pmd_leaf(pmd)) { VM_WARN_ON(1); return 1; } @@ -1276,7 +1276,7 @@ int pud_free_pmd_page(pud_t *pudp, unsigned long addr)
pud = READ_ONCE(*pudp);
- if (!pud_table(pud)) { + if (pud_leaf(pud)) { VM_WARN_ON(1); return 1; }