Re: [PATCH] powerpc/mm: Use pte_advance_pfn() in set_huge_pte_at()
From: Andrew Donnellan <hidden>
Date: 2026-01-12 04:23:50
On Thu, 2025-12-18 at 19:29 +0100, Christophe Leroy (CS GROUP) wrote:
quoted
for (i = 0; i < sz / pdsize; i++, ptep++, addr += pdsize) { __set_pte_at(mm, addr, ptep, pte, 0); - pte = __pte(pte_val(pte) + ((unsigned long long)pdsize / PAGE_SIZE << PFN_PTE_SHIFT)); + pte = pte_advance_pfn(pte, pdsize / PAGE_SIZE);How can this work ? pdsize is 4M, PAGE_SIZE is 4k so pdsize/PAGE_SIZE is 0x400. PFN_PTE_SHIFT is 24. 0x400 << 24 is more than what an unsigned long can contain in pte_advance_pfn()
Ah, in spite of the explicit unsigned long long cast that should've reminded me otherwise, I forgot that a long isn't 64 bits on 32 bit machines.
-- Andrew Donnellan OzLabs, ADL Canberra ajd@linux.ibm.com IBM Australia Limited