2 files changed, 61 insertions, 114 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 07c86f51d225..41c0a0a500f7 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -712,23 +712,6 @@ const struct file_operations proc_tid_smaps_operations = {
         .release        = proc_map_release,
 };
 
-/*
- * We do not want to have constant page-shift bits sitting in
- * pagemap entries and are about to reuse them some time soon.
- *
- * Here's the "migration strategy":
- * 1. when the system boots these bits remain what they are,
- *    but a warning about future change is printed in log;
- * 2. once anyone clears soft-dirty bits via clear_refs file,
- *    these flag is set to denote, that user is aware of the
- *    new API and those page-shift bits change their meaning.
- *    The respective warning is printed in dmesg;
- * 3. In a couple of releases we will remove all the mentions
- *    of page-shift in pagemap entries.
- */
-
-static bool soft_dirty_cleared __read_mostly;
-
 enum clear_refs_types {
         CLEAR_REFS_ALL = 1,
         CLEAR_REFS_ANON,
@@ -889,13 +872,6 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
         if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
                 return -EINVAL;
 
-        if (type == CLEAR_REFS_SOFT_DIRTY) {
-                soft_dirty_cleared = true;
-                pr_warn_once("The pagemap bits 55-60 has changed their meaning!"
-                             " See the linux/Documentation/vm/pagemap.txt for "
-                             "details.\n");
-        }
-
         task = get_proc_task(file_inode(file));
         if (!task)
                 return -ESRCH;
@@ -963,36 +939,24 @@ typedef struct {
 struct pagemapread {
         int pos, len;           /* units: PM_ENTRY_BYTES, not bytes */
         pagemap_entry_t *buffer;
-        bool v2;
 };
 
 #define PAGEMAP_WALK_SIZE       (PMD_SIZE)
 #define PAGEMAP_WALK_MASK       (PMD_MASK)
 
-#define PM_ENTRY_BYTES      sizeof(pagemap_entry_t)
-#define PM_STATUS_BITS      3
-#define PM_STATUS_OFFSET    (64 - PM_STATUS_BITS)
-#define PM_STATUS_MASK      (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
-#define PM_STATUS(nr)       (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
-#define PM_PSHIFT_BITS      6
-#define PM_PSHIFT_OFFSET    (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
-#define PM_PSHIFT_MASK      (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
-#define __PM_PSHIFT(x)      (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
-#define PM_PFRAME_MASK      ((1LL << PM_PSHIFT_OFFSET) - 1)
-#define PM_PFRAME(x)        ((x) & PM_PFRAME_MASK)
-/* in "new" pagemap pshift bits are occupied with more status bits */
-#define PM_STATUS2(v2, x)   (__PM_PSHIFT(v2 ? x : PAGE_SHIFT))
-
-#define __PM_SOFT_DIRTY      (1LL)
-#define PM_PRESENT          PM_STATUS(4LL)
-#define PM_SWAP             PM_STATUS(2LL)
-#define PM_FILE             PM_STATUS(1LL)
-#define PM_NOT_PRESENT(v2)  PM_STATUS2(v2, 0)
+#define PM_ENTRY_BYTES          sizeof(pagemap_entry_t)
+#define PM_PFRAME_BITS          55
+#define PM_PFRAME_MASK          GENMASK_ULL(PM_PFRAME_BITS - 1, 0)
+#define PM_SOFT_DIRTY           BIT_ULL(55)
+#define PM_FILE                 BIT_ULL(61)
+#define PM_SWAP                 BIT_ULL(62)
+#define PM_PRESENT              BIT_ULL(63)
+
 #define PM_END_OF_BUFFER    1
 
-static inline pagemap_entry_t make_pme(u64 val)
+static inline pagemap_entry_t make_pme(u64 frame, u64 flags)
 {
-        return (pagemap_entry_t) { .pme = val };
+        return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags };
 }
 
 static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
@@ -1013,7 +977,7 @@ static int pagemap_pte_hole(unsigned long start, unsigned long end,
 
         while (addr < end) {
                 struct vm_area_struct *vma = find_vma(walk->mm, addr);
-                pagemap_entry_t pme = make_pme(PM_NOT_PRESENT(pm->v2));
+                pagemap_entry_t pme = make_pme(0, 0);
                 /* End of address space hole, which we mark as non-present. */
                 unsigned long hole_end;
 
@@ -1033,7 +997,7 @@ static int pagemap_pte_hole(unsigned long start, unsigned long end,
 
                 /* Addresses in the VMA. */
                 if (vma->vm_flags & VM_SOFTDIRTY)
-                        pme.pme |= PM_STATUS2(pm->v2, __PM_SOFT_DIRTY);
+                        pme = make_pme(0, PM_SOFT_DIRTY);
                 for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
                         err = add_to_pagemap(addr, &pme, pm);
                         if (err)
@@ -1044,63 +1008,61 @@ out:
         return err;
 }
 
-static void pte_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
+static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
                 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
 {
-        u64 frame, flags;
+        u64 frame = 0, flags = 0;
         struct page *page = NULL;
-        int flags2 = 0;
 
         if (pte_present(pte)) {
                 frame = pte_pfn(pte);
-                flags = PM_PRESENT;
+                flags |= PM_PRESENT;
                 page = vm_normal_page(vma, addr, pte);
                 if (pte_soft_dirty(pte))
-                        flags2 |= __PM_SOFT_DIRTY;
+                        flags |= PM_SOFT_DIRTY;
         } else if (is_swap_pte(pte)) {
                 swp_entry_t entry;
                 if (pte_swp_soft_dirty(pte))
-                        flags2 |= __PM_SOFT_DIRTY;
+                        flags |= PM_SOFT_DIRTY;
                 entry = pte_to_swp_entry(pte);
                 frame = swp_type(entry) |
                         (swp_offset(entry) << MAX_SWAPFILES_SHIFT);
-                flags = PM_SWAP;
+                flags |= PM_SWAP;
                 if (is_migration_entry(entry))
                         page = migration_entry_to_page(entry);
-        } else {
-                if (vma->vm_flags & VM_SOFTDIRTY)
-                        flags2 |= __PM_SOFT_DIRTY;
-                *pme = make_pme(PM_NOT_PRESENT(pm->v2) | PM_STATUS2(pm->v2, flags2));
-                return;
         }
 
         if (page && !PageAnon(page))
                 flags |= PM_FILE;
-        if ((vma->vm_flags & VM_SOFTDIRTY))
-                flags2 |= __PM_SOFT_DIRTY;
+        if (vma->vm_flags & VM_SOFTDIRTY)
+                flags |= PM_SOFT_DIRTY;
 
-        *pme = make_pme(PM_PFRAME(frame) | PM_STATUS2(pm->v2, flags2) | flags);
+        return make_pme(frame, flags);
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
-                pmd_t pmd, int offset, int pmd_flags2)
+static pagemap_entry_t thp_pmd_to_pagemap_entry(struct pagemapread *pm,
+                pmd_t pmd, int offset, u64 flags)
 {
+        u64 frame = 0;
+
         /*
          * Currently pmd for thp is always present because thp can not be
          * swapped-out, migrated, or HWPOISONed (split in such cases instead.)
          * This if-check is just to prepare for future implementation.
          */
-        if (pmd_present(pmd))
-                *pme = make_pme(PM_PFRAME(pmd_pfn(pmd) + offset)
-                                | PM_STATUS2(pm->v2, pmd_flags2) | PM_PRESENT);
-        else
-                *pme = make_pme(PM_NOT_PRESENT(pm->v2) | PM_STATUS2(pm->v2, pmd_flags2));
+        if (pmd_present(pmd)) {
+                frame = pmd_pfn(pmd) + offset;
+                flags |= PM_PRESENT;
+        }
+
+        return make_pme(frame, flags);
 }
 #else
-static inline void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
-                pmd_t pmd, int offset, int pmd_flags2)
+static pagemap_entry_t thp_pmd_to_pagemap_entry(struct pagemapread *pm,
+                pmd_t pmd, int offset, u64 flags)
 {
+        return make_pme(0, 0);
 }
 #endif
 
@@ -1114,12 +1076,10 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
         int err = 0;
 
         if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
-                int pmd_flags2;
+                u64 flags = 0;
 
                 if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(*pmd))
-                        pmd_flags2 = __PM_SOFT_DIRTY;
-                else
-                        pmd_flags2 = 0;
+                        flags |= PM_SOFT_DIRTY;
 
                 for (; addr != end; addr += PAGE_SIZE) {
                         unsigned long offset;
@@ -1127,7 +1087,7 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 
                         offset = (addr & ~PAGEMAP_WALK_MASK) >>
                                         PAGE_SHIFT;
-                        thp_pmd_to_pagemap_entry(&pme, pm, *pmd, offset, pmd_flags2);
+                        pme = thp_pmd_to_pagemap_entry(pm, *pmd, offset, flags);
                         err = add_to_pagemap(addr, &pme, pm);
                         if (err)
                                 break;
@@ -1147,7 +1107,7 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
         for (; addr < end; pte++, addr += PAGE_SIZE) {
                 pagemap_entry_t pme;
 
-                pte_to_pagemap_entry(&pme, pm, vma, addr, *pte);
+                pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
                 err = add_to_pagemap(addr, &pme, pm);
                 if (err)
                         break;
@@ -1160,16 +1120,17 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 }
 
 #ifdef CONFIG_HUGETLB_PAGE
-static void huge_pte_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
-                                        pte_t pte, int offset, int flags2)
+static pagemap_entry_t huge_pte_to_pagemap_entry(struct pagemapread *pm,
+                                        pte_t pte, int offset, u64 flags)
 {
-        if (pte_present(pte))
-                *pme = make_pme(PM_PFRAME(pte_pfn(pte) + offset)        |
-                                PM_STATUS2(pm->v2, flags2)              |
-                                PM_PRESENT);
-        else
-                *pme = make_pme(PM_NOT_PRESENT(pm->v2)                  |
-                                PM_STATUS2(pm->v2, flags2));
+        u64 frame = 0;
+
+        if (pte_present(pte)) {
+                frame = pte_pfn(pte) + offset;
+                flags |= PM_PRESENT;
+        }
+
+        return make_pme(frame, flags);
 }
 
 /* This function walks within one hugetlb entry in the single call */
@@ -1180,17 +1141,15 @@ static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,
         struct pagemapread *pm = walk->private;
         struct vm_area_struct *vma = walk->vma;
         int err = 0;
-        int flags2;
+        u64 flags = 0;
         pagemap_entry_t pme;
 
         if (vma->vm_flags & VM_SOFTDIRTY)
-                flags2 = __PM_SOFT_DIRTY;
-        else
-                flags2 = 0;
+                flags |= PM_SOFT_DIRTY;
 
         for (; addr != end; addr += PAGE_SIZE) {
                 int offset = (addr & ~hmask) >> PAGE_SHIFT;
-                huge_pte_to_pagemap_entry(&pme, pm, *pte, offset, flags2);
+                pme = huge_pte_to_pagemap_entry(pm, *pte, offset, flags);
                 err = add_to_pagemap(addr, &pme, pm);
                 if (err)
                         return err;
@@ -1211,7 +1170,8 @@ static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,
  * Bits 0-54  page frame number (PFN) if present
  * Bits 0-4   swap type if swapped
  * Bits 5-54  swap offset if swapped
- * Bits 55-60 page shift (page size = 1<<page shift)
+ * Bit  55    pte is soft-dirty (see Documentation/vm/soft-dirty.txt)
+ * Bits 56-60 zero
  * Bit  61    page is file-page or shared-anon
  * Bit  62    page swapped
  * Bit  63    page present
@@ -1250,7 +1210,6 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
         if (!count)
                 goto out_mm;
 
-        pm.v2 = soft_dirty_cleared;
         pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
         pm.buffer = kmalloc(pm.len * PM_ENTRY_BYTES, GFP_TEMPORARY);
         ret = -ENOMEM;
@@ -1323,9 +1282,6 @@ static int pagemap_open(struct inode *inode, struct file *file)
         /* do not disclose physical addresses: attack vector */
         if (!capable(CAP_SYS_ADMIN))
                 return -EPERM;
-        pr_warn_once("Bits 55-60 of /proc/PID/pagemap entries are about "
-                        "to stop being page-shift some time soon. See the "
-                        "linux/Documentation/vm/pagemap.txt for details.\n");
 
         mm = proc_mem_open(inode, PTRACE_MODE_READ);
         if (IS_ERR(mm))
diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c
index 8bdf16b8ba60..603ec916716b 100644
--- a/tools/vm/page-types.c
+++ b/tools/vm/page-types.c
@@ -57,23 +57,14 @@
  * pagemap kernel ABI bits
  */
 
-#define PM_ENTRY_BYTES      sizeof(uint64_t)
-#define PM_STATUS_BITS      3
-#define PM_STATUS_OFFSET    (64 - PM_STATUS_BITS)
-#define PM_STATUS_MASK      (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
-#define PM_STATUS(nr)       (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
-#define PM_PSHIFT_BITS      6
-#define PM_PSHIFT_OFFSET    (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
-#define PM_PSHIFT_MASK      (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
-#define __PM_PSHIFT(x)      (((uint64_t) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
-#define PM_PFRAME_MASK      ((1LL << PM_PSHIFT_OFFSET) - 1)
-#define PM_PFRAME(x)        ((x) & PM_PFRAME_MASK)
-
-#define __PM_SOFT_DIRTY      (1LL)
-#define PM_PRESENT          PM_STATUS(4LL)
-#define PM_SWAP             PM_STATUS(2LL)
-#define PM_SOFT_DIRTY       __PM_PSHIFT(__PM_SOFT_DIRTY)
-
+#define PM_ENTRY_BYTES          8
+#define PM_PFRAME_BITS          55
+#define PM_PFRAME_MASK          ((1LL << PM_PFRAME_BITS) - 1)
+#define PM_PFRAME(x)            ((x) & PM_PFRAME_MASK)
+#define PM_SOFT_DIRTY           (1ULL << 55)
+#define PM_FILE                 (1ULL << 61)
+#define PM_SWAP                 (1ULL << 62)
+#define PM_PRESENT              (1ULL << 63)
 
 /*
  * kernel page flags