Merge tag 'vfs-6.8.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

[linux.git] / fs / proc / task_mmu.c

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 5de0f70e52ff4c0ba8296edb7e5e2f95b7045a25..1801e409a061d174aeb2742425bed12222f71a53 100644 (file)
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1983,15 +1983,31 @@ static int pagemap_scan_test_walk(unsigned long start, unsigned long end,
        struct pagemap_scan_private *p = walk->private;
        struct vm_area_struct *vma = walk->vma;
        unsigned long vma_category = 0;
+       bool wp_allowed = userfaultfd_wp_async(vma) &&
+           userfaultfd_wp_use_markers(vma);
 
-       if (userfaultfd_wp_async(vma) && userfaultfd_wp_use_markers(vma))
-               vma_category |= PAGE_IS_WPALLOWED;
-       else if (p->arg.flags & PM_SCAN_CHECK_WPASYNC)
-               return -EPERM;
+       if (!wp_allowed) {
+               /* User requested explicit failure over wp-async capability */
+               if (p->arg.flags & PM_SCAN_CHECK_WPASYNC)
+                       return -EPERM;
+               /*
+                * User requires wr-protect, and allows silently skipping
+                * unsupported vmas.
+                */
+               if (p->arg.flags & PM_SCAN_WP_MATCHING)
+                       return 1;
+               /*
+                * Then the request doesn't involve wr-protects at all,
+                * fall through to the rest checks, and allow vma walk.
+                */
+       }
 
        if (vma->vm_flags & VM_PFNMAP)
                return 1;
 
+       if (wp_allowed)
+               vma_category |= PAGE_IS_WPALLOWED;
+
        if (!pagemap_scan_is_interesting_vma(vma_category, p))
                return 1;
 
@@ -2141,7 +2157,7 @@ static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start,
                return 0;
        }
 
-       if (!p->vec_out) {
+       if ((p->arg.flags & PM_SCAN_WP_MATCHING) && !p->vec_out) {
                /* Fast path for performing exclusive WP */
                for (addr = start; addr != end; pte++, addr += PAGE_SIZE) {
                        if (pte_uffd_wp(ptep_get(pte)))