Merge tag 'filelock-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton...

[platform/kernel/linux-starfive.git] / mm / ksm.c

diff --git a/mm/ksm.c b/mm/ksm.c
index ba26635..d7b5b95 100644 (file)
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -455,6 +455,12 @@ static int break_ksm_pmd_entry(pmd_t *pmd, unsigned long addr, unsigned long nex
 
 static const struct mm_walk_ops break_ksm_ops = {
        .pmd_entry = break_ksm_pmd_entry,
+       .walk_lock = PGWALK_RDLOCK,
+};
+
+static const struct mm_walk_ops break_ksm_lock_vma_ops = {
+       .pmd_entry = break_ksm_pmd_entry,
+       .walk_lock = PGWALK_WRLOCK,
 };
 
 /*
@@ -470,16 +476,17 @@ static const struct mm_walk_ops break_ksm_ops = {
  * of the process that owns 'vma'.  We also do not want to enforce
  * protection keys here anyway.
  */
-static int break_ksm(struct vm_area_struct *vma, unsigned long addr)
+static int break_ksm(struct vm_area_struct *vma, unsigned long addr, bool lock_vma)
 {
        vm_fault_t ret = 0;
+       const struct mm_walk_ops *ops = lock_vma ?
+                               &break_ksm_lock_vma_ops : &break_ksm_ops;
 
        do {
                int ksm_page;
 
                cond_resched();
-               ksm_page = walk_page_range_vma(vma, addr, addr + 1,
-                                              &break_ksm_ops, NULL);
+               ksm_page = walk_page_range_vma(vma, addr, addr + 1, ops, NULL);
                if (WARN_ON_ONCE(ksm_page < 0))
                        return ksm_page;
                if (!ksm_page)
@@ -565,7 +572,7 @@ static void break_cow(struct ksm_rmap_item *rmap_item)
        mmap_read_lock(mm);
        vma = find_mergeable_vma(mm, addr);
        if (vma)
-               break_ksm(vma, addr);
+               break_ksm(vma, addr, false);
        mmap_read_unlock(mm);
 }
 
@@ -871,7 +878,7 @@ static void remove_trailing_rmap_items(struct ksm_rmap_item **rmap_list)
  * in cmp_and_merge_page on one of the rmap_items we would be removing.
  */
 static int unmerge_ksm_pages(struct vm_area_struct *vma,
-                            unsigned long start, unsigned long end)
+                            unsigned long start, unsigned long end, bool lock_vma)
 {
        unsigned long addr;
        int err = 0;
@@ -882,7 +889,7 @@ static int unmerge_ksm_pages(struct vm_area_struct *vma,
                if (signal_pending(current))
                        err = -ERESTARTSYS;
                else
-                       err = break_ksm(vma, addr);
+                       err = break_ksm(vma, addr, lock_vma);
        }
        return err;
 }
@@ -1029,7 +1036,7 @@ static int unmerge_and_remove_all_rmap_items(void)
                        if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
                                continue;
                        err = unmerge_ksm_pages(vma,
-                                               vma->vm_start, vma->vm_end);
+                                               vma->vm_start, vma->vm_end, false);
                        if (err)
                                goto error;
                }
@@ -2530,7 +2537,7 @@ static int __ksm_del_vma(struct vm_area_struct *vma)
                return 0;
 
        if (vma->anon_vma) {
-               err = unmerge_ksm_pages(vma, vma->vm_start, vma->vm_end);
+               err = unmerge_ksm_pages(vma, vma->vm_start, vma->vm_end, true);
                if (err)
                        return err;
        }
@@ -2668,7 +2675,7 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
                        return 0;               /* just ignore the advice */
 
                if (vma->anon_vma) {
-                       err = unmerge_ksm_pages(vma, start, end);
+                       err = unmerge_ksm_pages(vma, start, end, true);
                        if (err)
                                return err;
                }
@@ -2784,6 +2791,8 @@ struct page *ksm_might_need_to_copy(struct page *page,
                        anon_vma->root == vma->anon_vma->root) {
                return page;            /* still no need to copy it */
        }
+       if (PageHWPoison(page))
+               return ERR_PTR(-EHWPOISON);
        if (!PageUptodate(page))
                return page;            /* let do_swap_page report the error */