On 3/21/25 00:04, Peter Xu wrote: > Keith Busch observed some incorrect macros defined in arm64 code [1]. > > It turns out the two lines should never be needed and won't be exposed to > anyone, because aarch64 doesn't select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD, > hence ARCH_SUPPORTS_PUD_PFNMAP is always N. The only archs that support > THP PUDs so far are x86 and powerpc. Correct. > > Instead of fixing the lines (with no way to test it..), remove the two > lines that are in reality dead code, to avoid confusing readers. Agreed. Because ARCH_SUPPORTS_PUD_PFNMAP is always N and hence these lines are never reachable. So removing these lines will be preferred than fixing. > > Fixes tag is attached to reflect where the wrong macros were introduced, > but explicitly not copying stable, because there's no real issue to be > fixed. So it's only about removing the dead code so far. Makes sense. > > [1] https://lore.kernel.org/all/Z9tDjOk-JdV_fCY4@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/#t > > Cc: Alex Williamson <alex.williamson@xxxxxxxxxx> > Cc: Donald Dutile <ddutile@xxxxxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Will Deacon <will@xxxxxxxxxx> > Fixes: 3e509c9b03f9 ("mm/arm64: support large pfn mappings") The commit ID checks out. > Reported-by: Keith Busch <kbusch@xxxxxxxxxx> > Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> > --- > arch/arm64/include/asm/pgtable.h | 5 ----- > 1 file changed, 5 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 0b2a2ad1b9e8..15211f74b035 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -620,11 +620,6 @@ static inline pmd_t pmd_mkspecial(pmd_t pmd) > #define pud_pfn(pud) ((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT) > #define pfn_pud(pfn,prot) __pud(__phys_to_pud_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)) > > -#ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP > -#define pud_special(pte) pte_special(pud_pte(pud)) > -#define pud_mkspecial(pte) pte_pud(pte_mkspecial(pud_pte(pud))) > -#endif > - > #define pmd_pgprot pmd_pgprot > static inline pgprot_t pmd_pgprot(pmd_t pmd) > { LGTM Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
