page_vma_mapped.c | Explore in Territory

// SPDX-License-Identifier: GPL-2.0
#include <linux/mm.h>
#include <linux/rmap.h>
#include <linux/hugetlb.h>
#include <linux/swap.h>
#include <linux/swapops.h>

#include "internal.h"

static inline bool not_found(struct page_vma_mapped_walk *pvmw)
{ … }

static bool map_pte(struct page_vma_mapped_walk *pvmw, spinlock_t **ptlp)
{ … }

/**
 * check_pte - check if [pvmw->pfn, @pvmw->pfn + @pvmw->nr_pages) is
 * mapped at the @pvmw->pte
 * @pvmw: page_vma_mapped_walk struct, includes a pair pte and pfn range
 * for checking
 *
 * page_vma_mapped_walk() found a place where pfn range is *potentially*
 * mapped. check_pte() has to validate this.
 *
 * pvmw->pte may point to empty PTE, swap PTE or PTE pointing to
 * arbitrary page.
 *
 * If PVMW_MIGRATION flag is set, returns true if @pvmw->pte contains migration
 * entry that points to [pvmw->pfn, @pvmw->pfn + @pvmw->nr_pages)
 *
 * If PVMW_MIGRATION flag is not set, returns true if pvmw->pte points to
 * [pvmw->pfn, @pvmw->pfn + @pvmw->nr_pages)
 *
 * Otherwise, return false.
 *
 */
static bool check_pte(struct page_vma_mapped_walk *pvmw)
{ … }

/* Returns true if the two ranges overlap.  Careful to not overflow. */
static bool check_pmd(unsigned long pfn, struct page_vma_mapped_walk *pvmw)
{ … }

static void step_forward(struct page_vma_mapped_walk *pvmw, unsigned long size)
{ … }

/**
 * page_vma_mapped_walk - check if @pvmw->pfn is mapped in @pvmw->vma at
 * @pvmw->address
 * @pvmw: pointer to struct page_vma_mapped_walk. page, vma, address and flags
 * must be set. pmd, pte and ptl must be NULL.
 *
 * Returns true if the page is mapped in the vma. @pvmw->pmd and @pvmw->pte point
 * to relevant page table entries. @pvmw->ptl is locked. @pvmw->address is
 * adjusted if needed (for PTE-mapped THPs).
 *
 * If @pvmw->pmd is set but @pvmw->pte is not, you have found PMD-mapped page
 * (usually THP). For PTE-mapped THP, you should run page_vma_mapped_walk() in
 * a loop to find all PTEs that map the THP.
 *
 * For HugeTLB pages, @pvmw->pte is set to the relevant page table entry
 * regardless of which page table level the page is mapped at. @pvmw->pmd is
 * NULL.
 *
 * Returns false if there are no more page table entries for the page in
 * the vma. @pvmw->ptl is unlocked and @pvmw->pte is unmapped.
 *
 * If you need to stop the walk before page_vma_mapped_walk() returned false,
 * use page_vma_mapped_walk_done(). It will do the housekeeping.
 */
bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
{ … }

#ifdef CONFIG_MEMORY_FAILURE
/**
 * page_mapped_in_vma - check whether a page is really mapped in a VMA
 * @page: the page to test
 * @vma: the VMA to test
 *
 * Return: The address the page is mapped at if the page is in the range
 * covered by the VMA and present in the page table.  If the page is
 * outside the VMA or not present, returns -EFAULT.
 * Only valid for normal file or anonymous VMAs.
 */
unsigned long page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
{ … }
#endif
linux/mm/page_vma_mapped.c
