This IOCTL, PAGEMAP_SCAN on pagemap file can be used to get and/or clear the info about page table entries. The following operations are supported in this ioctl: - Get the information if the pages have been written-to (PAGE_IS_WRITTEN), file mapped (PAGE_IS_FILE), present (PAGE_IS_PRESENT), swapped (PAGE_IS_SWAPPED) or page has pfn zero (PAGE_IS_PFNZERO). - Find pages which have been written-to and/or write protect the pages (atomic PM_SCAN_OP_GET + PM_SCAN_OP_WP)
This IOCTL can be extended to get information about more PTE bits. The entire address range passed by user [start, end) is scanned until either the user provided buffer is full or max_pages have been found.
Signed-off-by: Muhammad Usama Anjum usama.anjum@collabora.com --- Changes in v22: - Interface change to return walk ending address to user: - Replace [start start + len) with [start, end) - Return the ending address of the address walk in start
Changes in v21: - Abort walk instead of returning error if WP is to be performed on partial hugetlb - Changed the data types of some variables in pagemap_scan_private to long
Changes in v20: - Correct PAGE_IS_FILE and add PAGE_IS_PFNZERO
Changes in v19: - Interface changes such as renaming, return mask and WP can be used with any flags specified in masks - Internal code changes
Changes in v18: - Rebased on top of next-20230613 - ptep_get() updates - remove pmd_trans_unstable() and add ACTION_AGAIN - Review updates (Micheal)
Changes in v17: - Rebased on next-20230606 - Made make_uffd_wp_*_pte() better and minor changes
Changes in v16: - Fixed a corner case where kernel writes beyond user buffer by one element - Bring back exclusive PM_SCAN_OP_WP - Cosmetic changes
Changes in v15: - Build fix: - Use generic tlb flush function in pagemap_scan_pmd_entry() instead of using x86 specific flush function in do_pagemap_scan() - Remove #ifdef from pagemap_scan_hugetlb_entry() - Use mm instead of undefined vma->vm_mm
Changes in v14: - Fix build error caused by #ifdef added at last minute in some configs
Changes in v13: - Review updates - mmap_read_lock_killable() instead of mmap_read_lock() - Replace uffd_wp_range() with helpers which increases performance drastically for OP_WP operations by reducing the number of tlb flushing etc - Add MMU_NOTIFY_PROTECTION_VMA notification for the memory range
Changes in v12: - Add hugetlb support to cover all memory types - Merge "userfaultfd: Define dummy uffd_wp_range()" with this patch - Review updates to the code
Changes in v11: - Find written pages in a better way - Fix a corner case (thanks Paul) - Improve the code/comments - remove ENGAGE_WP + ! GET operation - shorten the commit message in favour of moving documentation to pagemap.rst
Changes in v10: - move changes in tools/include/uapi/linux/fs.h to separate patch - update commit message
Change in v8: - Correct is_pte_uffd_wp() - Improve readability and error checks - Remove some un-needed code
Changes in v7: - Rebase on top of latest next - Fix some corner cases - Base soft-dirty on the uffd wp async - Update the terminologies - Optimize the memory usage inside the ioctl --- fs/proc/task_mmu.c | 565 ++++++++++++++++++++++++++++++++++++++++ include/linux/hugetlb.h | 1 + include/uapi/linux/fs.h | 55 ++++ mm/hugetlb.c | 2 +- 4 files changed, 622 insertions(+), 1 deletion(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 507cd4e59d07..be747fb89827 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -19,6 +19,7 @@ #include <linux/shmem_fs.h> #include <linux/uaccess.h> #include <linux/pkeys.h> +#include <linux/minmax.h>
#include <asm/elf.h> #include <asm/tlb.h> @@ -1765,11 +1766,575 @@ static int pagemap_release(struct inode *inode, struct file *file) return 0; }
+#define PM_SCAN_REQUIRE_UFFD (1ULL << 63) + +#define PM_SCAN_FOUND_MAX_PAGES (1) +#define PM_SCAN_END_WALK (-256) + +#define PM_SCAN_BITS_ALL (PAGE_IS_WRITTEN | PAGE_IS_FILE | \ + PAGE_IS_PRESENT | PAGE_IS_SWAPPED | \ + PAGE_IS_PFNZERO) +#define PM_SCAN_OPS (PM_SCAN_OP_GET | PM_SCAN_OP_WP) +#define IS_PM_SCAN_GET(flags) (flags & PM_SCAN_OP_GET) +#define IS_PM_SCAN_WP(flags) (flags & PM_SCAN_OP_WP) + +#define PM_SCAN_FLAGS(wt, file, present, swap, pfnzero) \ + ((wt) | ((file) << 1) | ((present) << 2) | \ + ((swap) << 3) | ((pfnzero) << 4)) + +struct pagemap_scan_private { + struct page_region *vec_buf, cur_buf; + unsigned long vec_buf_len, vec_buf_index, max_pages, found_pages; + unsigned long long flags, required_mask, anyof_mask, excluded_mask, return_mask; +}; + +static inline bool is_pte_uffd_wp(pte_t pte) +{ + return (pte_present(pte) && pte_uffd_wp(pte)) || + pte_swp_uffd_wp_any(pte); +} + +static inline void make_uffd_wp_pte(struct vm_area_struct *vma, + unsigned long addr, pte_t *pte) +{ + pte_t ptent = ptep_get(pte); + + if (pte_present(ptent)) { + pte_t old_pte; + + old_pte = ptep_modify_prot_start(vma, addr, pte); + ptent = pte_mkuffd_wp(ptent); + ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); + } else if (is_swap_pte(ptent)) { + ptent = pte_swp_mkuffd_wp(ptent); + set_pte_at(vma->vm_mm, addr, pte, ptent); + } else { + set_pte_at(vma->vm_mm, addr, pte, + make_pte_marker(PTE_MARKER_UFFD_WP)); + } +} + +static inline bool pagemap_scan_is_file(struct vm_area_struct *vma, pte_t ptent, + unsigned long addr) +{ + struct page *page = NULL; + swp_entry_t entry; + + if (pte_present(ptent)) { + page = vm_normal_page(vma, addr, ptent); + } else { + entry = pte_to_swp_entry(ptent); + if (is_pfn_swap_entry(entry)) + page = pfn_swap_entry_to_page(entry); + } + + if (page && !PageAnon(page)) + return true; + + return false; +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline bool is_pmd_uffd_wp(pmd_t pmd) +{ + return (pmd_present(pmd) && pmd_uffd_wp(pmd)) || + (is_swap_pmd(pmd) && pmd_swp_uffd_wp(pmd)); +} + +static inline void make_uffd_wp_pmd(struct vm_area_struct *vma, + unsigned long addr, pmd_t *pmdp) +{ + pmd_t old, pmd = *pmdp; + + if (pmd_present(pmd)) { + old = pmdp_invalidate_ad(vma, addr, pmdp); + pmd = pmd_mkuffd_wp(old); + set_pmd_at(vma->vm_mm, addr, pmdp, pmd); + } else if (is_migration_entry(pmd_to_swp_entry(pmd))) { + pmd = pmd_swp_mkuffd_wp(pmd); + set_pmd_at(vma->vm_mm, addr, pmdp, pmd); + } +} +#endif + +#ifdef CONFIG_HUGETLB_PAGE +static inline bool is_huge_pte_uffd_wp(pte_t pte) +{ + return (pte_present(pte) && huge_pte_uffd_wp(pte)) || + pte_swp_uffd_wp_any(pte); +} + +static inline void make_uffd_wp_huge_pte(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep, + pte_t ptent) +{ + if (is_hugetlb_entry_hwpoisoned(ptent) || is_pte_marker(ptent)) + return; + + if (is_hugetlb_entry_migration(ptent)) + set_huge_pte_at(vma->vm_mm, addr, ptep, + pte_swp_mkuffd_wp(ptent)); + else if (!huge_pte_none(ptent)) + huge_ptep_modify_prot_commit(vma, addr, ptep, ptent, + huge_pte_mkuffd_wp(ptent)); + else + set_huge_pte_at(vma->vm_mm, addr, ptep, + make_pte_marker(PTE_MARKER_UFFD_WP)); +} + +static inline bool pagemap_scan_is_huge_file(pte_t pte) +{ + if (pte_present(pte) && (!PageAnon(pte_page(pte)))) + return true; + + return false; +} +#endif + +static int pagemap_scan_test_walk(unsigned long start, unsigned long end, + struct mm_walk *walk) +{ + struct pagemap_scan_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + + if ((p->flags & PM_SCAN_REQUIRE_UFFD) && (!userfaultfd_wp_async(vma) || + !userfaultfd_wp_use_markers(vma))) + return -EPERM; + + if (vma->vm_flags & VM_PFNMAP) + return 1; + + return 0; +} + +static int pagemap_scan_output(unsigned long bitmap, + struct pagemap_scan_private *p, + unsigned long addr, unsigned int n_pages) +{ + struct page_region *cur_buf = &p->cur_buf; + + if (!n_pages) + return -EINVAL; + + bitmap &= p->return_mask; + + if (cur_buf->flags == bitmap && + cur_buf->start + cur_buf->len * PAGE_SIZE == addr) { + cur_buf->len += n_pages; + p->found_pages += n_pages; + } else { + if (cur_buf->len) { + if (p->vec_buf_index >= p->vec_buf_len) + return PM_SCAN_END_WALK; + + memcpy(&p->vec_buf[p->vec_buf_index], cur_buf, + sizeof(*p->vec_buf)); + p->vec_buf_index++; + } + + cur_buf->start = addr; + cur_buf->len = n_pages; + cur_buf->flags = bitmap; + p->found_pages += n_pages; + } + + if (p->found_pages == p->max_pages) + return PM_SCAN_FOUND_MAX_PAGES; + + return 0; +} + +static bool pagemap_scan_is_interesting_page(unsigned long bitmap, + struct pagemap_scan_private *p) +{ + if ((p->required_mask & bitmap) != p->required_mask) + return false; + if (p->anyof_mask && !(p->anyof_mask & bitmap)) + return false; + if (p->excluded_mask & bitmap) + return false; + + return true; +} + +static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start, + unsigned long end, struct mm_walk *walk) +{ + bool is_written, flush = false, interesting = true; + struct pagemap_scan_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + unsigned long bitmap, addr = end; + pte_t *pte, *orig_pte, ptent; + spinlock_t *ptl; + int ret = 0; + + arch_enter_lazy_mmu_mode(); + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + ptl = pmd_trans_huge_lock(pmd, vma); + if (ptl) { + unsigned long n_pages = (end - start)/PAGE_SIZE; + + if (n_pages > p->max_pages - p->found_pages) + n_pages = p->max_pages - p->found_pages; + + is_written = !is_pmd_uffd_wp(*pmd); + + bitmap = PM_SCAN_FLAGS(is_written, false, + pmd_present(*pmd), is_swap_pmd(*pmd), + pmd_present(*pmd) && is_zero_pfn(pmd_pfn(*pmd))); + + if (IS_PM_SCAN_GET(p->flags)) + interesting = pagemap_scan_is_interesting_page(bitmap, p); + + if (interesting) { + /* + * Break huge page into small pages if the WP operation + * need to be performed is on a portion of the huge page. + */ + if (is_written && IS_PM_SCAN_WP(p->flags) && + n_pages < HPAGE_SIZE/PAGE_SIZE) { + spin_unlock(ptl); + + split_huge_pmd(vma, pmd, start); + goto process_smaller_pages; + } + + if (IS_PM_SCAN_GET(p->flags)) + ret = pagemap_scan_output(bitmap, p, start, n_pages); + + if (IS_PM_SCAN_WP(p->flags) && is_written && ret >= 0) { + make_uffd_wp_pmd(vma, start, pmd); + flush_tlb_range(vma, start, end); + } + } + + spin_unlock(ptl); + arch_leave_lazy_mmu_mode(); + + return ret; + } + +process_smaller_pages: +#endif + + orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); + if (!pte) { + walk->action = ACTION_AGAIN; + return 0; + } + + for (addr = start; addr < end && !ret; pte++, addr += PAGE_SIZE) { + ptent = ptep_get(pte); + is_written = !is_pte_uffd_wp(ptent); + + bitmap = PM_SCAN_FLAGS(is_written, pagemap_scan_is_file(vma, ptent, addr), + pte_present(ptent), is_swap_pte(ptent), + pte_present(ptent) && is_zero_pfn(pte_pfn(ptent))); + + if (IS_PM_SCAN_GET(p->flags)) { + interesting = pagemap_scan_is_interesting_page(bitmap, p); + if (interesting) + ret = pagemap_scan_output(bitmap, p, addr, 1); + } + + if (IS_PM_SCAN_WP(p->flags) && is_written && interesting && + ret >= 0) { + make_uffd_wp_pte(vma, addr, pte); + flush = true; + } + } + + if (flush) + flush_tlb_range(vma, start, addr); + + pte_unmap_unlock(orig_pte, ptl); + arch_leave_lazy_mmu_mode(); + + cond_resched(); + return ret; +} + +#ifdef CONFIG_HUGETLB_PAGE +static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask, + unsigned long start, unsigned long end, + struct mm_walk *walk) +{ + unsigned long n_pages = (end - start)/PAGE_SIZE; + struct pagemap_scan_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + bool is_written, interesting = true; + struct hstate *h = hstate_vma(vma); + unsigned long bitmap; + spinlock_t *ptl; + int ret = 0; + pte_t ptent; + + if (IS_PM_SCAN_WP(p->flags) && n_pages < HPAGE_SIZE/PAGE_SIZE) + return -EINVAL; + + if (n_pages > p->max_pages - p->found_pages) + n_pages = p->max_pages - p->found_pages; + + if (IS_PM_SCAN_WP(p->flags)) { + i_mmap_lock_write(vma->vm_file->f_mapping); + ptl = huge_pte_lock(h, vma->vm_mm, ptep); + } + + ptent = huge_ptep_get(ptep); + is_written = !is_huge_pte_uffd_wp(ptent); + + bitmap = PM_SCAN_FLAGS(is_written, pagemap_scan_is_huge_file(ptent), + pte_present(ptent), is_swap_pte(ptent), + pte_present(ptent) && is_zero_pfn(pte_pfn(ptent))); + + if (IS_PM_SCAN_GET(p->flags)) + interesting = pagemap_scan_is_interesting_page(bitmap, p); + + if (interesting) { + /* + * Partial hugetlb page clear isn't supported + */ + if (is_written && IS_PM_SCAN_WP(p->flags) && + n_pages < HPAGE_SIZE/PAGE_SIZE) { + ret = PM_SCAN_END_WALK; + goto unlock_and_return; + } + + if (IS_PM_SCAN_GET(p->flags)) + ret = pagemap_scan_output(bitmap, p, start, n_pages); + + if (IS_PM_SCAN_WP(p->flags) && is_written && ret >= 0) { + make_uffd_wp_huge_pte(vma, start, ptep, ptent); + flush_hugetlb_tlb_range(vma, start, end); + } + } + +unlock_and_return: + if (IS_PM_SCAN_WP(p->flags)) { + spin_unlock(ptl); + i_mmap_unlock_write(vma->vm_file->f_mapping); + } + + return ret; +} +#else +#define pagemap_scan_hugetlb_entry NULL +#endif + +static int pagemap_scan_pte_hole(unsigned long addr, unsigned long end, + int depth, struct mm_walk *walk) +{ + unsigned long n_pages = (end - addr)/PAGE_SIZE; + struct pagemap_scan_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + int ret = 0; + + if (!vma || !IS_PM_SCAN_GET(p->flags)) + return 0; + + if (n_pages > p->max_pages - p->found_pages) + n_pages = p->max_pages - p->found_pages; + + ret = pagemap_scan_output(PM_SCAN_FLAGS(false, false, false, false, false), + p, addr, n_pages); + + return ret; +} + +static const struct mm_walk_ops pagemap_scan_ops = { + .test_walk = pagemap_scan_test_walk, + .pmd_entry = pagemap_scan_pmd_entry, + .pte_hole = pagemap_scan_pte_hole, + .hugetlb_entry = pagemap_scan_hugetlb_entry, +}; + +static int pagemap_scan_args_valid(struct pm_scan_arg *arg, unsigned long start, + unsigned long end, struct page_region __user *vec) +{ + /* Detect illegal size, flags, len and masks */ + if (arg->size != sizeof(struct pm_scan_arg)) + return -EINVAL; + if (!arg->flags) + return -EINVAL; + if (arg->flags & ~PM_SCAN_OPS) + return -EINVAL; + if (!(end - start)) + return -EINVAL; + if ((arg->required_mask | arg->anyof_mask | arg->excluded_mask | + arg->return_mask) & ~PM_SCAN_BITS_ALL) + return -EINVAL; + if (!arg->required_mask && !arg->anyof_mask && + !arg->excluded_mask) + return -EINVAL; + if (!arg->return_mask) + return -EINVAL; + + /* Validate memory range */ + if (!IS_ALIGNED(start, PAGE_SIZE)) + return -EINVAL; + if (!access_ok((void __user *)start, end - start)) + return -EFAULT; + + if (IS_PM_SCAN_GET(arg->flags)) { + if (arg->vec_len == 0) + return -EINVAL; + if (!vec) + return -EINVAL; + if (!access_ok((void __user *)vec, + arg->vec_len * sizeof(struct page_region))) + return -EFAULT; + } + + if (IS_PM_SCAN_WP(arg->flags) && !IS_PM_SCAN_GET(arg->flags) && + arg->max_pages) + return -EINVAL; + + return 0; +} + +static long do_pagemap_scan(struct mm_struct *mm, unsigned long __arg) +{ + struct pm_scan_arg __user *uarg = (struct pm_scan_arg __user *)__arg; + unsigned long long start, end, walk_start, walk_end; + unsigned long empty_slots, vec_index = 0; + struct mmu_notifier_range range; + struct page_region __user *vec; + struct pagemap_scan_private p; + struct pm_scan_arg arg; + int ret = 0; + + if (copy_from_user(&arg, uarg, sizeof(arg))) + return -EFAULT; + + start = untagged_addr((unsigned long)arg.start); + end = untagged_addr((unsigned long)arg.end); + vec = (struct page_region __user *)untagged_addr((unsigned long)arg.vec); + + ret = pagemap_scan_args_valid(&arg, start, end, vec); + if (ret) + return ret; + + p.max_pages = (arg.max_pages) ? arg.max_pages : ULONG_MAX; + p.found_pages = 0; + p.required_mask = arg.required_mask; + p.anyof_mask = arg.anyof_mask; + p.excluded_mask = arg.excluded_mask; + p.return_mask = arg.return_mask; + p.flags = arg.flags; + p.flags |= ((p.required_mask | p.anyof_mask | p.excluded_mask) & + PAGE_IS_WRITTEN) ? PM_SCAN_REQUIRE_UFFD : 0; + p.cur_buf.start = p.cur_buf.len = p.cur_buf.flags = 0; + p.vec_buf = NULL; + p.vec_buf_len = PAGEMAP_WALK_SIZE >> PAGE_SHIFT; + + /* + * Allocate smaller buffer to get output from inside the page walk + * functions and walk page range in PAGEMAP_WALK_SIZE size chunks. As + * we want to return output to user in compact form where no two + * consecutive regions should be continuous and have the same flags. + * So store the latest element in p.cur_buf between different walks and + * store the p.cur_buf at the end of the walk to the user buffer. + */ + if (IS_PM_SCAN_GET(p.flags)) { + p.vec_buf = kmalloc_array(p.vec_buf_len, sizeof(*p.vec_buf), + GFP_KERNEL); + if (!p.vec_buf) + return -ENOMEM; + } + + if (IS_PM_SCAN_WP(p.flags)) { + mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 0, + mm, start, end); + mmu_notifier_invalidate_range_start(&range); + } + + walk_start = walk_end = start; + while (walk_end < end && !ret) { + if (IS_PM_SCAN_GET(p.flags)) { + p.vec_buf_index = 0; + + /* + * All data is copied to cur_buf first. When more data + * is found, we push cur_buf to vec_buf and copy new + * data to cur_buf. Subtract 1 from length as the + * index of cur_buf isn't counted in length. + */ + empty_slots = arg.vec_len - vec_index; + p.vec_buf_len = min(p.vec_buf_len, empty_slots - 1); + } + + ret = mmap_read_lock_killable(mm); + if (ret) + goto return_status; + + walk_end = min((walk_start + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK, end); + + ret = walk_page_range(mm, walk_start, walk_end, + &pagemap_scan_ops, &p); + mmap_read_unlock(mm); + + if (ret && ret != PM_SCAN_FOUND_MAX_PAGES && + ret != PM_SCAN_END_WALK) + goto return_status; + + walk_start = walk_end; + if (IS_PM_SCAN_GET(p.flags) && p.vec_buf_index) { + if (copy_to_user(&vec[vec_index], p.vec_buf, + p.vec_buf_index * sizeof(*p.vec_buf))) { + /* + * Return error even though the OP succeeded + */ + ret = -EFAULT; + goto return_status; + } + vec_index += p.vec_buf_index; + } + } + + if (p.cur_buf.len) { + if (copy_to_user(&vec[vec_index], &p.cur_buf, sizeof(p.cur_buf))) { + ret = -EFAULT; + goto return_status; + } + vec_index++; + } + + ret = vec_index; + +return_status: + arg.start = (unsigned long)walk_end; + if (copy_to_user(&uarg->start, &arg.start, sizeof(arg.start))) + ret = -EFAULT; + + if (IS_PM_SCAN_WP(p.flags)) + mmu_notifier_invalidate_range_end(&range); + + kfree(p.vec_buf); + return ret; +} + +static long do_pagemap_cmd(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct mm_struct *mm = file->private_data; + + switch (cmd) { + case PAGEMAP_SCAN: + return do_pagemap_scan(mm, arg); + + default: + return -EINVAL; + } +} + const struct file_operations proc_pagemap_operations = { .llseek = mem_lseek, /* borrow this */ .read = pagemap_read, .open = pagemap_open, .release = pagemap_release, + .unlocked_ioctl = do_pagemap_cmd, + .compat_ioctl = do_pagemap_cmd, }; #endif /* CONFIG_PROC_PAGE_MONITOR */
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index beb7c63d2871..a6e773c3e2b4 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -261,6 +261,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma, unsigned long cp_flags);
bool is_hugetlb_entry_migration(pte_t pte); +bool is_hugetlb_entry_hwpoisoned(pte_t pte); void hugetlb_unshare_all_pmds(struct vm_area_struct *vma);
#else /* !CONFIG_HUGETLB_PAGE */ diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index b7b56871029c..ac684d99e68f 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -305,4 +305,59 @@ typedef int __bitwise __kernel_rwf_t; #define RWF_SUPPORTED (RWF_HIPRI | RWF_DSYNC | RWF_SYNC | RWF_NOWAIT |\ RWF_APPEND)
+/* Pagemap ioctl */ +#define PAGEMAP_SCAN _IOWR('f', 16, struct pm_scan_arg) + +/* Bits are set in flags of the page_region and masks in pm_scan_args */ +#define PAGE_IS_WRITTEN (1 << 0) +#define PAGE_IS_FILE (1 << 1) +#define PAGE_IS_PRESENT (1 << 2) +#define PAGE_IS_SWAPPED (1 << 3) +#define PAGE_IS_PFNZERO (1 << 4) + +/* + * struct page_region - Page region with flags + * @start: Start of the region + * @len: Length of the region in pages + * @bitmap: Bits sets for the region + */ +struct page_region { + __u64 start; + __u64 len; + __u64 flags; +}; + +/* + * struct pm_scan_arg - Pagemap ioctl argument + * @size: Size of the structure + * @flags: Flags for the IOCTL + * @start: Starting address of the region + * (Ending address of the walk is also returned in it) + * @end: Ending address of the region + * @vec: Address of page_region struct array for output + * @vec_len: Length of the page_region struct array + * @max_pages: Optional max return pages + * @required_mask: Required mask - All of these bits have to be set in the PTE + * @anyof_mask: Any mask - Any of these bits are set in the PTE + * @excluded_mask: Exclude mask - None of these bits are set in the PTE + * @return_mask: Bits that are to be reported in page_region + */ +struct pm_scan_arg { + __u64 size; + __u64 flags; + __u64 start; + __u64 end; + __u64 vec; + __u64 vec_len; + __u64 max_pages; + __u64 required_mask; + __u64 anyof_mask; + __u64 excluded_mask; + __u64 return_mask; +}; + +/* Supported flags */ +#define PM_SCAN_OP_GET (1 << 0) +#define PM_SCAN_OP_WP (1 << 1) + #endif /* _UAPI_LINUX_FS_H */ diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 0db13167b1ee..7e60f0f3fd03 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4980,7 +4980,7 @@ bool is_hugetlb_entry_migration(pte_t pte) return false; }
-static bool is_hugetlb_entry_hwpoisoned(pte_t pte) +bool is_hugetlb_entry_hwpoisoned(pte_t pte) { swp_entry_t swp;