net/mlx5: Fix some error handling paths in 'mlx5e_tc_add_fdb_flow()'

[mirror_ubuntu-jammy-kernel.git] / fs / proc / task_mmu.c

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index cf25be3e0321206b5a45f66ae2cfc2084e7f947c..3d3067c8d868260d160dc77ead9320306272f079 100644 (file)
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -280,7 +280,10 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
        const char *name = NULL;
 
        if (file) {
-               struct inode *inode = file_inode(vma->vm_file);
+               struct inode *inode;
+
+               file = vma_pr_or_file(vma);
+               inode = file_inode(file);
                dev = inode->i_sb->s_dev;
                ino = inode->i_ino;
                pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT;
@@ -430,7 +433,8 @@ static void smaps_page_accumulate(struct mem_size_stats *mss,
 }
 
 static void smaps_account(struct mem_size_stats *mss, struct page *page,
-               bool compound, bool young, bool dirty, bool locked)
+               bool compound, bool young, bool dirty, bool locked,
+               bool migration)
 {
        int i, nr = compound ? compound_nr(page) : 1;
        unsigned long size = nr * PAGE_SIZE;
@@ -457,8 +461,15 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
         * page_count(page) == 1 guarantees the page is mapped exactly once.
         * If any subpage of the compound page mapped with PTE it would elevate
         * page_count().
+        *
+        * The page_mapcount() is called to get a snapshot of the mapcount.
+        * Without holding the page lock this snapshot can be slightly wrong as
+        * we cannot always read the mapcount atomically.  It is not safe to
+        * call page_mapcount() even with PTL held if the page is not mapped,
+        * especially for migration entries.  Treat regular migration entries
+        * as mapcount == 1.
         */
-       if (page_count(page) == 1) {
+       if ((page_count(page) == 1) || migration) {
                smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
                        locked, true);
                return;
@@ -495,6 +506,7 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
        struct vm_area_struct *vma = walk->vma;
        bool locked = !!(vma->vm_flags & VM_LOCKED);
        struct page *page = NULL;
+       bool migration = false;
 
        if (pte_present(*pte)) {
                page = vm_normal_page(vma, addr, *pte);
@@ -514,8 +526,11 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
                        } else {
                                mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT;
                        }
-               } else if (is_pfn_swap_entry(swpent))
+               } else if (is_pfn_swap_entry(swpent)) {
+                       if (is_migration_entry(swpent))
+                               migration = true;
                        page = pfn_swap_entry_to_page(swpent);
+               }
        } else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
                                                        && pte_none(*pte))) {
                page = xa_load(&vma->vm_file->f_mapping->i_pages,
@@ -528,7 +543,8 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
        if (!page)
                return;
 
-       smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte), locked);
+       smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte),
+                     locked, migration);
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -539,6 +555,7 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
        struct vm_area_struct *vma = walk->vma;
        bool locked = !!(vma->vm_flags & VM_LOCKED);
        struct page *page = NULL;
+       bool migration = false;
 
        if (pmd_present(*pmd)) {
                /* FOLL_DUMP will return -EFAULT on huge zero page */
@@ -546,8 +563,10 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
        } else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
                swp_entry_t entry = pmd_to_swp_entry(*pmd);
 
-               if (is_migration_entry(entry))
+               if (is_migration_entry(entry)) {
+                       migration = true;
                        page = pfn_swap_entry_to_page(entry);
+               }
        }
        if (IS_ERR_OR_NULL(page))
                return;
@@ -559,7 +578,9 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
                /* pass */;
        else
                mss->file_thp += HPAGE_PMD_SIZE;
-       smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), locked);
+
+       smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
+                     locked, migration);
 }
 #else
 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
@@ -1363,6 +1384,7 @@ static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
 {
        u64 frame = 0, flags = 0;
        struct page *page = NULL;
+       bool migration = false;
 
        if (pte_present(pte)) {
                if (pm->show_pfn)
@@ -1384,13 +1406,14 @@ static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
                        frame = swp_type(entry) |
                                (swp_offset(entry) << MAX_SWAPFILES_SHIFT);
                flags |= PM_SWAP;
+               migration = is_migration_entry(entry);
                if (is_pfn_swap_entry(entry))
                        page = pfn_swap_entry_to_page(entry);
        }
 
        if (page && !PageAnon(page))
                flags |= PM_FILE;
-       if (page && page_mapcount(page) == 1)
+       if (page && !migration && page_mapcount(page) == 1)
                flags |= PM_MMAP_EXCLUSIVE;
        if (vma->vm_flags & VM_SOFTDIRTY)
                flags |= PM_SOFT_DIRTY;
@@ -1406,8 +1429,9 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
        spinlock_t *ptl;
        pte_t *pte, *orig_pte;
        int err = 0;
-
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
+       bool migration = false;
+
        ptl = pmd_trans_huge_lock(pmdp, vma);
        if (ptl) {
                u64 flags = 0, frame = 0;
@@ -1446,11 +1470,12 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
                        if (pmd_swp_uffd_wp(pmd))
                                flags |= PM_UFFD_WP;
                        VM_BUG_ON(!is_pmd_migration_entry(pmd));
+                       migration = is_migration_entry(entry);
                        page = pfn_swap_entry_to_page(entry);
                }
 #endif
 
-               if (page && page_mapcount(page) == 1)
+               if (page && !migration && page_mapcount(page) == 1)
                        flags |= PM_MMAP_EXCLUSIVE;
 
                for (; addr != end; addr += PAGE_SIZE) {
@@ -1560,7 +1585,8 @@ static const struct mm_walk_ops pagemap_ops = {
  * Bits 5-54  swap offset if swapped
  * Bit  55    pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst)
  * Bit  56    page exclusively mapped
- * Bits 57-60 zero
+ * Bit  57    pte is uffd-wp write-protected
+ * Bits 58-60 zero
  * Bit  61    page is file-page or shared-anon
  * Bit  62    page swapped
  * Bit  63    page present
@@ -1865,7 +1891,7 @@ static int show_numa_map(struct seq_file *m, void *v)
        struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
        struct vm_area_struct *vma = v;
        struct numa_maps *md = &numa_priv->md;
-       struct file *file = vma->vm_file;
+       struct file *file = vma_pr_or_file(vma);
        struct mm_struct *mm = vma->vm_mm;
        struct mempolicy *pol;
        char buffer[64];