The patch titled Subject: um/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE has been added to the -mm mm-unstable branch. Its filename is um-mm-support-__have_arch_pte_swp_exclusive.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/um-mm-support-__have_arch_pte_swp_exclusive.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: David Hildenbrand <david@xxxxxxxxxx> Subject: um/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE Date: Fri, 13 Jan 2023 18:10:23 +0100 Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by using bit 10, which is yet unused for swap PTEs. The pte_mkuptodate() is a bit weird in __pte_to_swp_entry() for a swap PTE ... but it only messes with bit 1 and 2 and there is a comment in set_pte(), so leave these bits alone. While at it, mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-24-david@xxxxxxxxxx Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Richard Weinberger <richard@xxxxxx> Cc: Anton Ivanov <anton.ivanov@xxxxxxxxxxxxxxxxxx> Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- --- a/arch/um/include/asm/pgtable.h~um-mm-support-__have_arch_pte_swp_exclusive +++ a/arch/um/include/asm/pgtable.h @@ -21,6 +21,9 @@ #define _PAGE_PROTNONE 0x010 /* if the user mapped it with PROT_NONE; pte_present gives true */ +/* We borrow bit 10 to store the exclusive marker in swap PTEs. */ +#define _PAGE_SWP_EXCLUSIVE 0x400 + #ifdef CONFIG_3_LEVEL_PGTABLES #include <asm/pgtable-3level.h> #else @@ -288,16 +291,46 @@ extern pte_t *virt_to_pte(struct mm_stru #define update_mmu_cache(vma,address,ptep) do {} while (0) -/* Encode and de-code a swap entry */ +/* + * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that + * are !pte_none() && !pte_present(). + * + * Format of swap PTEs: + * + * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 + * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 + * <--------------- offset ----------------> E < type -> 0 0 0 1 0 + * + * E is the exclusive marker that is not stored in swap entries. + * _PAGE_NEWPAGE (bit 1) is always set to 1 in set_pte(). + */ #define __swp_type(x) (((x).val >> 5) & 0x1f) #define __swp_offset(x) ((x).val >> 11) #define __swp_entry(type, offset) \ - ((swp_entry_t) { ((type) << 5) | ((offset) << 11) }) + ((swp_entry_t) { (((type) & 0x1f) << 5) | ((offset) << 11) }) #define __pte_to_swp_entry(pte) \ ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) +#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE +static inline int pte_swp_exclusive(pte_t pte) +{ + return pte_get_bits(pte, _PAGE_SWP_EXCLUSIVE); +} + +static inline pte_t pte_swp_mkexclusive(pte_t pte) +{ + pte_set_bits(pte, _PAGE_SWP_EXCLUSIVE); + return pte; +} + +static inline pte_t pte_swp_clear_exclusive(pte_t pte) +{ + pte_clear_bits(pte, _PAGE_SWP_EXCLUSIVE); + return pte; +} + /* Clear a kernel PTE and flush it from the TLB */ #define kpte_clear_flush(ptep, vaddr) \ do { \ _ Patches currently in -mm which might be from david@xxxxxxxxxx are mm-userfaultfd-rely-on-vma-vm_page_prot-in-uffd_wp_range.patch mm-userfaultfd-rely-on-vma-vm_page_prot-in-uffd_wp_range-fix.patch mm-mprotect-drop-pgprot_t-parameter-from-change_protection.patch mm-mprotect-drop-pgprot_t-parameter-from-change_protection-fix.patch selftests-vm-cow-add-cow-tests-for-collapsing-of-pte-mapped-anon-thp.patch mm-nommu-factor-out-check-for-nommu-shared-mappings-into-is_nommu_shared_mapping.patch mm-nommu-dont-use-vm_mayshare-for-map_private-mappings.patch drivers-misc-open-dice-dont-touch-vm_mayshare.patch selftests-mm-define-madv_pageout-to-fix-compilation-issues.patch mm-debug_vm_pgtable-more-pte_swp_exclusive-sanity-checks.patch alpha-mm-support-__have_arch_pte_swp_exclusive.patch arc-mm-support-__have_arch_pte_swp_exclusive.patch arm-mm-support-__have_arch_pte_swp_exclusive.patch csky-mm-support-__have_arch_pte_swp_exclusive.patch hexagon-mm-support-__have_arch_pte_swp_exclusive.patch ia64-mm-support-__have_arch_pte_swp_exclusive.patch loongarch-mm-support-__have_arch_pte_swp_exclusive.patch m68k-mm-remove-dummy-__swp-definitions-for-nommu.patch m68k-mm-support-__have_arch_pte_swp_exclusive.patch microblaze-mm-support-__have_arch_pte_swp_exclusive.patch mips-mm-support-__have_arch_pte_swp_exclusive.patch nios2-mm-refactor-swap-pte-layout.patch nios2-mm-support-__have_arch_pte_swp_exclusive.patch openrisc-mm-support-__have_arch_pte_swp_exclusive.patch parisc-mm-support-__have_arch_pte_swp_exclusive.patch powerpc-mm-support-__have_arch_pte_swp_exclusive-on-32bit-book3s.patch powerpc-nohash-mm-support-__have_arch_pte_swp_exclusive.patch riscv-mm-support-__have_arch_pte_swp_exclusive.patch sh-mm-support-__have_arch_pte_swp_exclusive.patch sparc-mm-support-__have_arch_pte_swp_exclusive-on-32bit.patch sparc-mm-support-__have_arch_pte_swp_exclusive-on-64bit.patch um-mm-support-__have_arch_pte_swp_exclusive.patch x86-mm-support-__have_arch_pte_swp_exclusive-also-on-32bit.patch xtensa-mm-support-__have_arch_pte_swp_exclusive.patch mm-remove-__have_arch_pte_swp_exclusive.patch