maps4: move clear_refs code to task_mmu.c

This puts all the clear_refs code where it belongs and probably lets things
compile on MMU-less systems as well.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 37 insertions, 53 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 33537487f5a..1bd646d3fe9 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -88,10 +88,6 @@
  *      in /proc for a task before it execs a suid executable.
  */
 
-
-/* Worst case buffer size needed for holding an integer. */
-#define PROC_NUMBUF 13
-
 struct pid_entry {
         char *name;
         int len;
@@ -935,42 +931,6 @@ static const struct file_operations proc_oom_adjust_operations = {
         .write          = oom_adjust_write,
 };
 
-#ifdef CONFIG_MMU
-static ssize_t clear_refs_write(struct file *file, const char __user *buf,
-                                size_t count, loff_t *ppos)
-{
-        struct task_struct *task;
-        char buffer[PROC_NUMBUF], *end;
-        struct mm_struct *mm;
-
-        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) {
-                clear_refs_smap(mm);
-                mmput(mm);
-        }
-        put_task_struct(task);
-        if (end - buffer == 0)
-                return -EIO;
-        return end - buffer;
-}
-
-static struct file_operations proc_clear_refs_operations = {
-        .write          = clear_refs_write,
-};
-#endif
-
 #ifdef CONFIG_AUDITSYSCALL
 #define TMPBUFLEN 21
 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 05b3e900626..ddfaeec3749 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -56,11 +56,7 @@ extern int proc_pid_statm(struct task_struct *, char *);
 extern const struct file_operations proc_maps_operations;
 extern const struct file_operations proc_numa_maps_operations;
 extern const struct file_operations proc_smaps_operations;
-
-extern const struct file_operations proc_maps_operations;
-extern const struct file_operations proc_numa_maps_operations;
-extern const struct file_operations proc_smaps_operations;
-
+extern const struct file_operations proc_clear_refs_operations;
 
 void free_proc_entry(struct proc_dir_entry *de);
 
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index abc44f39f1d..fcdbd233f25 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -323,19 +323,47 @@ static int show_smap(struct seq_file *m, void *v)
 
 static struct mm_walk clear_refs_walk = { .pmd_entry = clear_refs_pte_range };
 
-void clear_refs_smap(struct mm_struct *mm)
+static ssize_t clear_refs_write(struct file *file, const char __user *buf,
+                                size_t count, loff_t *ppos)
 {
+        struct task_struct *task;
+        char buffer[PROC_NUMBUF], *end;
+        struct mm_struct *mm;
         struct vm_area_struct *vma;
 
-        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->vm_mm, vma->vm_start, vma->vm_end,
-                                        &clear_refs_walk, vma);
-        flush_tlb_mm(mm);
-        up_read(&mm->mmap_sem);
+        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;
 }
 
+const struct file_operations proc_clear_refs_operations = {
+        .write          = clear_refs_write,
+};
+
 static void *m_start(struct seq_file *m, loff_t *pos)
 {
         struct proc_maps_private *priv = m->private;