1 files changed, 436 insertions, 240 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 8043a3eab52..38338ed98cc 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -5,7 +5,10 @@
 #include <linux/highmem.h>
 #include <linux/ptrace.h>
 #include <linux/pagemap.h>
+#include <linux/ptrace.h>
 #include <linux/mempolicy.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
 
 #include <asm/elf.h>
 #include <asm/uaccess.h>
@@ -114,24 +117,124 @@ static void pad_len_spaces(struct seq_file *m, int len)
         seq_printf(m, "%*c", len, ' ');
 }
 
-struct mem_size_stats
+static void vma_stop(struct proc_maps_private *priv, struct vm_area_struct *vma)
 {
-        unsigned long resident;
-        unsigned long shared_clean;
-        unsigned long shared_dirty;
-        unsigned long private_clean;
-        unsigned long private_dirty;
-        unsigned long referenced;
-};
+        if (vma && vma != priv->tail_vma) {
+                struct mm_struct *mm = vma->vm_mm;
+                up_read(&mm->mmap_sem);
+                mmput(mm);
+        }
+}
 
-struct pmd_walker {
-        struct vm_area_struct *vma;
-        void *private;
-        void (*action)(struct vm_area_struct *, pmd_t *, unsigned long,
-                       unsigned long, void *);
-};
+static void *m_start(struct seq_file *m, loff_t *pos)
+{
+        struct proc_maps_private *priv = m->private;
+        unsigned long last_addr = m->version;
+        struct mm_struct *mm;
+        struct vm_area_struct *vma, *tail_vma = NULL;
+        loff_t l = *pos;
+
+        /* Clear the per syscall fields in priv */
+        priv->task = NULL;
+        priv->tail_vma = NULL;
+
+        /*
+         * We remember last_addr rather than next_addr to hit with
+         * mmap_cache most of the time. We have zero last_addr at
+         * the beginning and also after lseek. We will have -1 last_addr
+         * after the end of the vmas.
+         */
+
+        if (last_addr == -1UL)
+                return NULL;
+
+        priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
+        if (!priv->task)
+                return NULL;
+
+        mm = mm_for_maps(priv->task);
+        if (!mm)
+                return NULL;
+
+        tail_vma = get_gate_vma(priv->task);
+        priv->tail_vma = tail_vma;
+
+        /* Start with last addr hint */
+        vma = find_vma(mm, last_addr);
+        if (last_addr && vma) {
+                vma = vma->vm_next;
+                goto out;
+        }
+
+        /*
+         * Check the vma index is within the range and do
+         * sequential scan until m_index.
+         */
+        vma = NULL;
+        if ((unsigned long)l < mm->map_count) {
+                vma = mm->mmap;
+                while (l-- && vma)
+                        vma = vma->vm_next;
+                goto out;
+        }
+
+        if (l != mm->map_count)
+                tail_vma = NULL; /* After gate vma */
+
+out:
+        if (vma)
+                return vma;
+
+        /* End of vmas has been reached */
+        m->version = (tail_vma != NULL)? 0: -1UL;
+        up_read(&mm->mmap_sem);
+        mmput(mm);
+        return tail_vma;
+}
 
-static int show_map_internal(struct seq_file *m, void *v, struct mem_size_stats *mss)
+static void *m_next(struct seq_file *m, void *v, loff_t *pos)
+{
+        struct proc_maps_private *priv = m->private;
+        struct vm_area_struct *vma = v;
+        struct vm_area_struct *tail_vma = priv->tail_vma;
+
+        (*pos)++;
+        if (vma && (vma != tail_vma) && vma->vm_next)
+                return vma->vm_next;
+        vma_stop(priv, vma);
+        return (vma != tail_vma)? tail_vma: NULL;
+}
+
+static void m_stop(struct seq_file *m, void *v)
+{
+        struct proc_maps_private *priv = m->private;
+        struct vm_area_struct *vma = v;
+
+        vma_stop(priv, vma);
+        if (priv->task)
+                put_task_struct(priv->task);
+}
+
+static int do_maps_open(struct inode *inode, struct file *file,
+                        struct seq_operations *ops)
+{
+        struct proc_maps_private *priv;
+        int ret = -ENOMEM;
+        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+        if (priv) {
+                priv->pid = proc_pid(inode);
+                ret = seq_open(file, ops);
+                if (!ret) {
+                        struct seq_file *m = file->private_data;
+                        m->private = priv;
+                } else {
+                        kfree(priv);
+                }
+        }
+        return ret;
+}
+
+static int show_map(struct seq_file *m, void *v)
 {
         struct proc_maps_private *priv = m->private;
         struct task_struct *task = priv->task;
@@ -191,41 +294,71 @@ static int show_map_internal(struct seq_file *m, void *v, struct mem_size_stats
         }
         seq_putc(m, '\n');
 
-        if (mss)
-                seq_printf(m,
-                           "Size:           %8lu kB\n"
-                           "Rss:            %8lu kB\n"
-                           "Shared_Clean:   %8lu kB\n"
-                           "Shared_Dirty:   %8lu kB\n"
-                           "Private_Clean:  %8lu kB\n"
-                           "Private_Dirty:  %8lu kB\n"
-                           "Referenced:     %8lu kB\n",
-                           (vma->vm_end - vma->vm_start) >> 10,
-                           mss->resident >> 10,
-                           mss->shared_clean  >> 10,
-                           mss->shared_dirty  >> 10,
-                           mss->private_clean >> 10,
-                           mss->private_dirty >> 10,
-                           mss->referenced >> 10);
-
         if (m->count < m->size)  /* vma is copied successfully */
                 m->version = (vma != get_gate_vma(task))? vma->vm_start: 0;
         return 0;
 }
 
-static int show_map(struct seq_file *m, void *v)
+static struct seq_operations proc_pid_maps_op = {
+        .start  = m_start,
+        .next   = m_next,
+        .stop   = m_stop,
+        .show   = show_map
+};
+
+static int maps_open(struct inode *inode, struct file *file)
 {
-        return show_map_internal(m, v, NULL);
+        return do_maps_open(inode, file, &proc_pid_maps_op);
 }
 
-static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
-                            unsigned long addr, unsigned long end,
-                            void *private)
+const struct file_operations proc_maps_operations = {
+        .open           = maps_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = seq_release_private,
+};
+
+/*
+ * Proportional Set Size(PSS): my share of RSS.
+ *
+ * PSS of a process is the count of pages it has in memory, where each
+ * page is divided by the number of processes sharing it.  So if a
+ * process has 1000 pages all to itself, and 1000 shared with one other
+ * process, its PSS will be 1500.
+ *
+ * To keep (accumulated) division errors low, we adopt a 64bit
+ * fixed-point pss counter to minimize division errors. So (pss >>
+ * PSS_SHIFT) would be the real byte count.
+ *
+ * A shift of 12 before division means (assuming 4K page size):
+ *      - 1M 3-user-pages add up to 8KB errors;
+ *      - supports mapcount up to 2^24, or 16M;
+ *      - supports PSS up to 2^52 bytes, or 4PB.
+ */
+#define PSS_SHIFT 12
+
+#ifdef CONFIG_PROC_PAGE_MONITOR
+struct mem_size_stats
+{
+        struct vm_area_struct *vma;
+        unsigned long resident;
+        unsigned long shared_clean;
+        unsigned long shared_dirty;
+        unsigned long private_clean;
+        unsigned long private_dirty;
+        unsigned long referenced;
+        u64 pss;
+};
+
+static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
+                           void *private)
 {
         struct mem_size_stats *mss = private;
+        struct vm_area_struct *vma = mss->vma;
         pte_t *pte, ptent;
         spinlock_t *ptl;
         struct page *page;
+        int mapcount;
 
         pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
         for (; addr != end; pte++, addr += PAGE_SIZE) {
@@ -242,26 +375,88 @@ static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
                 /* Accumulate the size in pages that have been accessed. */
                 if (pte_young(ptent) || PageReferenced(page))
                         mss->referenced += PAGE_SIZE;
-                if (page_mapcount(page) >= 2) {
+                mapcount = page_mapcount(page);
+                if (mapcount >= 2) {
                         if (pte_dirty(ptent))
                                 mss->shared_dirty += PAGE_SIZE;
                         else
                                 mss->shared_clean += PAGE_SIZE;
+                        mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
                 } else {
                         if (pte_dirty(ptent))
                                 mss->private_dirty += PAGE_SIZE;
                         else
                                 mss->private_clean += PAGE_SIZE;
+                        mss->pss += (PAGE_SIZE << PSS_SHIFT);
                 }
         }
         pte_unmap_unlock(pte - 1, ptl);
         cond_resched();
+        return 0;
 }
 
-static void clear_refs_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
-                                 unsigned long addr, unsigned long end,
-                                 void *private)
+static struct mm_walk smaps_walk = { .pmd_entry = smaps_pte_range };
+
+static int show_smap(struct seq_file *m, void *v)
 {
+        struct vm_area_struct *vma = v;
+        struct mem_size_stats mss;
+        int ret;
+
+        memset(&mss, 0, sizeof mss);
+        mss.vma = vma;
+        if (vma->vm_mm && !is_vm_hugetlb_page(vma))
+                walk_page_range(vma->vm_mm, vma->vm_start, vma->vm_end,
+                                &smaps_walk, &mss);
+
+        ret = show_map(m, v);
+        if (ret)
+                return ret;
+
+        seq_printf(m,
+                   "Size:           %8lu kB\n"
+                   "Rss:            %8lu kB\n"
+                   "Pss:            %8lu kB\n"
+                   "Shared_Clean:   %8lu kB\n"
+                   "Shared_Dirty:   %8lu kB\n"
+                   "Private_Clean:  %8lu kB\n"
+                   "Private_Dirty:  %8lu kB\n"
+                   "Referenced:     %8lu kB\n",
+                   (vma->vm_end - vma->vm_start) >> 10,
+                   mss.resident >> 10,
+                   (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
+                   mss.shared_clean  >> 10,
+                   mss.shared_dirty  >> 10,
+                   mss.private_clean >> 10,
+                   mss.private_dirty >> 10,
+                   mss.referenced >> 10);
+
+        return ret;
+}
+
+static struct seq_operations proc_pid_smaps_op = {
+        .start  = m_start,
+        .next   = m_next,
+        .stop   = m_stop,
+        .show   = show_smap
+};
+
+static int smaps_open(struct inode *inode, struct file *file)
+{
+        return do_maps_open(inode, file, &proc_pid_smaps_op);
+}
+
+const struct file_operations proc_smaps_operations = {
+        .open           = smaps_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = seq_release_private,
+};
+
+static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
+                                unsigned long end, void *private)
+{
+        struct vm_area_struct *vma = private;
         pte_t *pte, ptent;
         spinlock_t *ptl;
         struct page *page;
@@ -282,235 +477,248 @@ static void clear_refs_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
         }
         pte_unmap_unlock(pte - 1, ptl);
         cond_resched();
+        return 0;
 }
 
-static inline void walk_pmd_range(struct pmd_walker *walker, pud_t *pud,
-                                  unsigned long addr, unsigned long end)
+static struct mm_walk clear_refs_walk = { .pmd_entry = clear_refs_pte_range };
+
+static ssize_t clear_refs_write(struct file *file, const char __user *buf,
+                                size_t count, loff_t *ppos)
 {
-        pmd_t *pmd;
-        unsigned long next;
+        struct task_struct *task;
+        char buffer[PROC_NUMBUF], *end;
+        struct mm_struct *mm;
+        struct vm_area_struct *vma;
 
-        for (pmd = pmd_offset(pud, addr); addr != end;
-             pmd++, addr = next) {
-                next = pmd_addr_end(addr, end);
-                if (pmd_none_or_clear_bad(pmd))
-                        continue;
-                walker->action(walker->vma, pmd, addr, next, walker->private);
+        memset(buffer, 0, sizeof(buffer));
+        if (count > sizeof(buffer) - 1)
+                count = sizeof(buffer) - 1;
+        if (copy_from_user(buffer, buf, count))
+                return -EFAULT;
+        if (!simple_strtol(buffer, &end, 0))
+                return -EINVAL;
+        if (*end == '\n')
+                end++;
+        task = get_proc_task(file->f_path.dentry->d_inode);
+        if (!task)
+                return -ESRCH;
+        mm = get_task_mm(task);
+        if (mm) {
+                down_read(&mm->mmap_sem);
+                for (vma = mm->mmap; vma; vma = vma->vm_next)
+                        if (!is_vm_hugetlb_page(vma))
+                                walk_page_range(mm, vma->vm_start, vma->vm_end,
+                                                &clear_refs_walk, vma);
+                flush_tlb_mm(mm);
+                up_read(&mm->mmap_sem);
+                mmput(mm);
         }
+        put_task_struct(task);
+        if (end - buffer == 0)
+                return -EIO;
+        return end - buffer;
 }
 
-static inline void walk_pud_range(struct pmd_walker *walker, pgd_t *pgd,
-                                  unsigned long addr, unsigned long end)
-{
-        pud_t *pud;
-        unsigned long next;
+const struct file_operations proc_clear_refs_operations = {
+        .write          = clear_refs_write,
+};
 
-        for (pud = pud_offset(pgd, addr); addr != end;
-             pud++, addr = next) {
-                next = pud_addr_end(addr, end);
-                if (pud_none_or_clear_bad(pud))
-                        continue;
-                walk_pmd_range(walker, pud, addr, next);
+struct pagemapread {
+        char __user *out, *end;
+};
+
+#define PM_ENTRY_BYTES sizeof(u64)
+#define PM_RESERVED_BITS    3
+#define PM_RESERVED_OFFSET  (64 - PM_RESERVED_BITS)
+#define PM_RESERVED_MASK    (((1LL<<PM_RESERVED_BITS)-1) << PM_RESERVED_OFFSET)
+#define PM_SPECIAL(nr)      (((nr) << PM_RESERVED_OFFSET) | PM_RESERVED_MASK)
+#define PM_NOT_PRESENT      PM_SPECIAL(1LL)
+#define PM_SWAP             PM_SPECIAL(2LL)
+#define PM_END_OF_BUFFER    1
+
+static int add_to_pagemap(unsigned long addr, u64 pfn,
+                          struct pagemapread *pm)
+{
+        /*
+         * Make sure there's room in the buffer for an
+         * entire entry.  Otherwise, only copy part of
+         * the pfn.
+         */
+        if (pm->out + PM_ENTRY_BYTES >= pm->end) {
+                if (copy_to_user(pm->out, &pfn, pm->end - pm->out))
+                        return -EFAULT;
+                pm->out = pm->end;
+                return PM_END_OF_BUFFER;
         }
+
+        if (put_user(pfn, pm->out))
+                return -EFAULT;
+        pm->out += PM_ENTRY_BYTES;
+        return 0;
 }
 
-/*
- * walk_page_range - walk the page tables of a VMA with a callback
- * @vma - VMA to walk
- * @action - callback invoked for every bottom-level (PTE) page table
- * @private - private data passed to the callback function
- *
- * Recursively walk the page table for the memory area in a VMA, calling
- * a callback for every bottom-level (PTE) page table.
- */
-static inline void walk_page_range(struct vm_area_struct *vma,
-                                   void (*action)(struct vm_area_struct *,
-                                                  pmd_t *, unsigned long,
-                                                  unsigned long, void *),
-                                   void *private)
+static int pagemap_pte_hole(unsigned long start, unsigned long end,
+                                void *private)
 {
-        unsigned long addr = vma->vm_start;
-        unsigned long end = vma->vm_end;
-        struct pmd_walker walker = {
-                .vma            = vma,
-                .private        = private,
-                .action         = action,
-        };
-        pgd_t *pgd;
-        unsigned long next;
-
-        for (pgd = pgd_offset(vma->vm_mm, addr); addr != end;
-             pgd++, addr = next) {
-                next = pgd_addr_end(addr, end);
-                if (pgd_none_or_clear_bad(pgd))
-                        continue;
-                walk_pud_range(&walker, pgd, addr, next);
+        struct pagemapread *pm = private;
+        unsigned long addr;
+        int err = 0;
+        for (addr = start; addr < end; addr += PAGE_SIZE) {
+                err = add_to_pagemap(addr, PM_NOT_PRESENT, pm);
+                if (err)
+                        break;
         }
+        return err;
 }
 
-static int show_smap(struct seq_file *m, void *v)
+u64 swap_pte_to_pagemap_entry(pte_t pte)
 {
-        struct vm_area_struct *vma = v;
-        struct mem_size_stats mss;
-
-        memset(&mss, 0, sizeof mss);
-        if (vma->vm_mm && !is_vm_hugetlb_page(vma))
-                walk_page_range(vma, smaps_pte_range, &mss);
-        return show_map_internal(m, v, &mss);
+        swp_entry_t e = pte_to_swp_entry(pte);
+        return PM_SWAP | swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT);
 }
 
-void clear_refs_smap(struct mm_struct *mm)
+static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
+                             void *private)
 {
-        struct vm_area_struct *vma;
+        struct pagemapread *pm = private;
+        pte_t *pte;
+        int err = 0;
+
+        for (; addr != end; addr += PAGE_SIZE) {
+                u64 pfn = PM_NOT_PRESENT;
+                pte = pte_offset_map(pmd, addr);
+                if (is_swap_pte(*pte))
+                        pfn = swap_pte_to_pagemap_entry(*pte);
+                else if (pte_present(*pte))
+                        pfn = pte_pfn(*pte);
+                /* unmap so we're not in atomic when we copy to userspace */
+                pte_unmap(pte);
+                err = add_to_pagemap(addr, pfn, pm);
+                if (err)
+                        return err;
+        }
 
-        down_read(&mm->mmap_sem);
-        for (vma = mm->mmap; vma; vma = vma->vm_next)
-                if (vma->vm_mm && !is_vm_hugetlb_page(vma))
-                        walk_page_range(vma, clear_refs_pte_range, NULL);
-        flush_tlb_mm(mm);
-        up_read(&mm->mmap_sem);
+        cond_resched();
+
+        return err;
 }
 
-static void *m_start(struct seq_file *m, loff_t *pos)
+static struct mm_walk pagemap_walk = {
+        .pmd_entry = pagemap_pte_range,
+        .pte_hole = pagemap_pte_hole
+};
+
+/*
+ * /proc/pid/pagemap - an array mapping virtual pages to pfns
+ *
+ * For each page in the address space, this file contains one 64-bit
+ * entry representing the corresponding physical page frame number
+ * (PFN) if the page is present. If there is a swap entry for the
+ * physical page, then an encoding of the swap file number and the
+ * page's offset into the swap file are returned. If no page is
+ * present at all, PM_NOT_PRESENT is returned. This allows determining
+ * precisely which pages are mapped (or in swap) and comparing mapped
+ * pages between processes.
+ *
+ * Efficient users of this interface will use /proc/pid/maps to
+ * determine which areas of memory are actually mapped and llseek to
+ * skip over unmapped regions.
+ */
+static ssize_t pagemap_read(struct file *file, char __user *buf,
+                            size_t count, loff_t *ppos)
 {
-        struct proc_maps_private *priv = m->private;
-        unsigned long last_addr = m->version;
+        struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
+        struct page **pages, *page;
+        unsigned long uaddr, uend;
         struct mm_struct *mm;
-        struct vm_area_struct *vma, *tail_vma = NULL;
-        loff_t l = *pos;
-
-        /* Clear the per syscall fields in priv */
-        priv->task = NULL;
-        priv->tail_vma = NULL;
+        struct pagemapread pm;
+        int pagecount;
+        int ret = -ESRCH;
 
-        /*
-         * We remember last_addr rather than next_addr to hit with
-         * mmap_cache most of the time. We have zero last_addr at
-         * the beginning and also after lseek. We will have -1 last_addr
-         * after the end of the vmas.
-         */
+        if (!task)
+                goto out;
 
-        if (last_addr == -1UL)
-                return NULL;
+        ret = -EACCES;
+        if (!ptrace_may_attach(task))
+                goto out;
 
-        priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
-        if (!priv->task)
-                return NULL;
+        ret = -EINVAL;
+        /* file position must be aligned */
+        if (*ppos % PM_ENTRY_BYTES)
+                goto out;
 
-        mm = mm_for_maps(priv->task);
+        ret = 0;
+        mm = get_task_mm(task);
         if (!mm)
-                return NULL;
-
-        priv->tail_vma = tail_vma = get_gate_vma(priv->task);
-
-        /* Start with last addr hint */
-        if (last_addr && (vma = find_vma(mm, last_addr))) {
-                vma = vma->vm_next;
                 goto out;
-        }
 
-        /*
-         * Check the vma index is within the range and do
-         * sequential scan until m_index.
-         */
-        vma = NULL;
-        if ((unsigned long)l < mm->map_count) {
-                vma = mm->mmap;
-                while (l-- && vma)
-                        vma = vma->vm_next;
-                goto out;
-        }
+        ret = -ENOMEM;
+        uaddr = (unsigned long)buf & PAGE_MASK;
+        uend = (unsigned long)(buf + count);
+        pagecount = (PAGE_ALIGN(uend) - uaddr) / PAGE_SIZE;
+        pages = kmalloc(pagecount * sizeof(struct page *), GFP_KERNEL);
+        if (!pages)
+                goto out_task;
 
-        if (l != mm->map_count)
-                tail_vma = NULL; /* After gate vma */
+        down_read(&current->mm->mmap_sem);
+        ret = get_user_pages(current, current->mm, uaddr, pagecount,
+                             1, 0, pages, NULL);
+        up_read(&current->mm->mmap_sem);
 
-out:
-        if (vma)
-                return vma;
+        if (ret < 0)
+                goto out_free;
 
-        /* End of vmas has been reached */
-        m->version = (tail_vma != NULL)? 0: -1UL;
-        up_read(&mm->mmap_sem);
-        mmput(mm);
-        return tail_vma;
-}
+        pm.out = buf;
+        pm.end = buf + count;
 
-static void vma_stop(struct proc_maps_private *priv, struct vm_area_struct *vma)
-{
-        if (vma && vma != priv->tail_vma) {
-                struct mm_struct *mm = vma->vm_mm;
-                up_read(&mm->mmap_sem);
-                mmput(mm);
+        if (!ptrace_may_attach(task)) {
+                ret = -EIO;
+        } else {
+                unsigned long src = *ppos;
+                unsigned long svpfn = src / PM_ENTRY_BYTES;
+                unsigned long start_vaddr = svpfn << PAGE_SHIFT;
+                unsigned long end_vaddr = TASK_SIZE_OF(task);
+
+                /* watch out for wraparound */
+                if (svpfn > TASK_SIZE_OF(task) >> PAGE_SHIFT)
+                        start_vaddr = end_vaddr;
+
+                /*
+                 * The odds are that this will stop walking way
+                 * before end_vaddr, because the length of the
+                 * user buffer is tracked in "pm", and the walk
+                 * will stop when we hit the end of the buffer.
+                 */
+                ret = walk_page_range(mm, start_vaddr, end_vaddr,
+                                        &pagemap_walk, &pm);
+                if (ret == PM_END_OF_BUFFER)
+                        ret = 0;
+                /* don't need mmap_sem for these, but this looks cleaner */
+                *ppos += pm.out - buf;
+                if (!ret)
+                        ret = pm.out - buf;
         }
-}
-
-static void *m_next(struct seq_file *m, void *v, loff_t *pos)
-{
-        struct proc_maps_private *priv = m->private;
-        struct vm_area_struct *vma = v;
-        struct vm_area_struct *tail_vma = priv->tail_vma;
-
-        (*pos)++;
-        if (vma && (vma != tail_vma) && vma->vm_next)
-                return vma->vm_next;
-        vma_stop(priv, vma);
-        return (vma != tail_vma)? tail_vma: NULL;
-}
-
-static void m_stop(struct seq_file *m, void *v)
-{
-        struct proc_maps_private *priv = m->private;
-        struct vm_area_struct *vma = v;
 
-        vma_stop(priv, vma);
-        if (priv->task)
-                put_task_struct(priv->task);
-}
-
-static struct seq_operations proc_pid_maps_op = {
-        .start  = m_start,
-        .next   = m_next,
-        .stop   = m_stop,
-        .show   = show_map
-};
-
-static struct seq_operations proc_pid_smaps_op = {
-        .start  = m_start,
-        .next   = m_next,
-        .stop   = m_stop,
-        .show   = show_smap
-};
-
-static int do_maps_open(struct inode *inode, struct file *file,
-                        struct seq_operations *ops)
-{
-        struct proc_maps_private *priv;
-        int ret = -ENOMEM;
-        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
-        if (priv) {
-                priv->pid = proc_pid(inode);
-                ret = seq_open(file, ops);
-                if (!ret) {
-                        struct seq_file *m = file->private_data;
-                        m->private = priv;
-                } else {
-                        kfree(priv);
-                }
+        for (; pagecount; pagecount--) {
+                page = pages[pagecount-1];
+                if (!PageReserved(page))
+                        SetPageDirty(page);
+                page_cache_release(page);
         }
+        mmput(mm);
+out_free:
+        kfree(pages);
+out_task:
+        put_task_struct(task);
+out:
         return ret;
 }
 
-static int maps_open(struct inode *inode, struct file *file)
-{
-        return do_maps_open(inode, file, &proc_pid_maps_op);
-}
-
-const struct file_operations proc_maps_operations = {
-        .open           = maps_open,
-        .read           = seq_read,
-        .llseek         = seq_lseek,
-        .release        = seq_release_private,
+const struct file_operations proc_pagemap_operations = {
+        .llseek         = mem_lseek, /* borrow this */
+        .read           = pagemap_read,
 };
+#endif /* CONFIG_PROC_PAGE_MONITOR */
 
 #ifdef CONFIG_NUMA
 extern int show_numa_map(struct seq_file *m, void *v);
@@ -545,15 +753,3 @@ const struct file_operations proc_numa_maps_operations = {
         .release        = seq_release_private,
 };
 #endif
-
-static int smaps_open(struct inode *inode, struct file *file)
-{
-        return do_maps_open(inode, file, &proc_pid_smaps_op);
-}
-
-const struct file_operations proc_smaps_operations = {
-        .open           = smaps_open,
-        .read           = seq_read,
-        .llseek         = seq_lseek,
-        .release        = seq_release_private,
-};