Merge tag 'mm-hotfixes-stable-2022-09-26' of git://git.kernel.org/pub/scm/linux/kerne...

[people/ms/linux.git] / mm / memory-failure.c

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 14439806b5efc40327aefa05777422bcfca50611..e7ac570dda75dd1d63a7380a095de4a2d25a0f5c 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -345,13 +345,17 @@ static unsigned long dev_pagemap_mapping_shift(struct vm_area_struct *vma,
  * not much we can do. We just print a message and ignore otherwise.
  */
 
+#define FSDAX_INVALID_PGOFF ULONG_MAX
+
 /*
  * Schedule a process for later kill.
  * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM.
  *
- * Notice: @fsdax_pgoff is used only when @p is a fsdax page.
- *   In other cases, such as anonymous and file-backend page, the address to be
- *   killed can be caculated by @p itself.
+ * Note: @fsdax_pgoff is used only when @p is a fsdax page and a
+ * filesystem with a memory failure handler has claimed the
+ * memory_failure event. In all other cases, page->index and
+ * page->mapping are sufficient for mapping the page back to its
+ * corresponding user virtual address.
  */
 static void add_to_kill(struct task_struct *tsk, struct page *p,
                        pgoff_t fsdax_pgoff, struct vm_area_struct *vma,
@@ -367,11 +371,7 @@ static void add_to_kill(struct task_struct *tsk, struct page *p,
 
        tk->addr = page_address_in_vma(p, vma);
        if (is_zone_device_page(p)) {
-               /*
-                * Since page->mapping is not used for fsdax, we need
-                * calculate the address based on the vma.
-                */
-               if (p->pgmap->type == MEMORY_DEVICE_FS_DAX)
+               if (fsdax_pgoff != FSDAX_INVALID_PGOFF)
                        tk->addr = vma_pgoff_address(fsdax_pgoff, 1, vma);
                tk->size_shift = dev_pagemap_mapping_shift(vma, tk->addr);
        } else
@@ -523,7 +523,8 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill,
                        if (!page_mapped_in_vma(page, vma))
                                continue;
                        if (vma->vm_mm == t->mm)
-                               add_to_kill(t, page, 0, vma, to_kill);
+                               add_to_kill(t, page, FSDAX_INVALID_PGOFF, vma,
+                                           to_kill);
                }
        }
        read_unlock(&tasklist_lock);
@@ -559,7 +560,8 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill,
                         * to be informed of all such data corruptions.
                         */
                        if (vma->vm_mm == t->mm)
-                               add_to_kill(t, page, 0, vma, to_kill);
+                               add_to_kill(t, page, FSDAX_INVALID_PGOFF, vma,
+                                           to_kill);
                }
        }
        read_unlock(&tasklist_lock);
@@ -743,6 +745,9 @@ static int kill_accessing_process(struct task_struct *p, unsigned long pfn,
        };
        priv.tk.tsk = p;
 
+       if (!p->mm)
+               return -EFAULT;
+
        mmap_read_lock(p->mm);
        ret = walk_page_range(p->mm, 0, TASK_SIZE, &hwp_walk_ops,
                              (void *)&priv);
@@ -1928,7 +1933,7 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
         * Call driver's implementation to handle the memory failure, otherwise
         * fall back to generic handler.
         */
-       if (pgmap->ops->memory_failure) {
+       if (pgmap_has_memory_failure(pgmap)) {
                rc = pgmap->ops->memory_failure(pgmap, pfn, 1, flags);
                /*
                 * Fall back to generic handler too if operation is not