1 files changed, 49 insertions, 52 deletions

diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index 2fd06f52b6a4..d362919f4f68 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -38,7 +38,7 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
 		}
 
 		if (atomic_read(&mm->mm_count) > 1 ||
-		    vma->vm_flags & VM_MAYSHARE) {
+		    is_nommu_shared_mapping(vma->vm_flags)) {
 			sbytes += size;
 		} else {
 			bytes += size;
@@ -51,7 +51,7 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
 		sbytes += kobjsize(mm);
 	else
 		bytes += kobjsize(mm);
-	
+
 	if (current->fs && current->fs->users > 1)
 		sbytes += kobjsize(current->fs);
 	else
@@ -69,13 +69,13 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
 
 	bytes += kobjsize(current); /* includes kernel stack */
 
+	mmap_read_unlock(mm);
+
 	seq_printf(m,
 		"Mem:\t%8lu bytes\n"
 		"Slack:\t%8lu bytes\n"
 		"Shared:\t%8lu bytes\n",
 		bytes, slack, sbytes);
-
-	mmap_read_unlock(mm);
 }
 
 unsigned long task_vsize(struct mm_struct *mm)
@@ -121,19 +121,6 @@ unsigned long task_statm(struct mm_struct *mm,
 	return size;
 }
 
-static int is_stack(struct vm_area_struct *vma)
-{
-	struct mm_struct *mm = vma->vm_mm;
-
-	/*
-	 * We make no effort to guess what a given thread considers to be
-	 * its "stack".  It's not even well-defined for programs written
-	 * languages like Go.
-	 */
-	return vma->vm_start <= mm->start_stack &&
-		vma->vm_end >= mm->start_stack;
-}
-
 /*
  * display a single VMA to a sequenced file
  */
@@ -170,8 +157,8 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
 
 	if (file) {
 		seq_pad(m, ' ');
-		seq_file_path(m, file, "");
-	} else if (mm && is_stack(vma)) {
+		seq_path(m, file_user_path(file), "");
+	} else if (mm && vma_is_initial_stack(vma)) {
 		seq_pad(m, ' ');
 		seq_puts(m, "[stack]");
 	}
@@ -188,15 +175,28 @@ static int show_map(struct seq_file *m, void *_p)
 	return nommu_vma_show(m, _p);
 }
 
-static void *m_start(struct seq_file *m, loff_t *pos)
+static struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv,
+						loff_t *ppos)
+{
+	struct vm_area_struct *vma = vma_next(&priv->iter);
+
+	if (vma) {
+		*ppos = vma->vm_start;
+	} else {
+		*ppos = -1UL;
+	}
+
+	return vma;
+}
+
+static void *m_start(struct seq_file *m, loff_t *ppos)
 {
 	struct proc_maps_private *priv = m->private;
+	unsigned long last_addr = *ppos;
 	struct mm_struct *mm;
-	struct vm_area_struct *vma;
-	unsigned long addr = *pos;
 
-	/* See m_next(). Zero at the start or after lseek. */
-	if (addr == -1UL)
+	/* See proc_get_vma(). Zero at the start or after lseek. */
+	if (last_addr == -1UL)
 		return NULL;
 
 	/* pin the task and mm whilst we play with them */
@@ -204,45 +204,42 @@ static void *m_start(struct seq_file *m, loff_t *pos)
 	if (!priv->task)
 		return ERR_PTR(-ESRCH);
 
-	mm = priv->mm;
-	if (!mm || !mmget_not_zero(mm))
+	mm = priv->lock_ctx.mm;
+	if (!mm || !mmget_not_zero(mm)) {
+		put_task_struct(priv->task);
+		priv->task = NULL;
 		return NULL;
+	}
 
 	if (mmap_read_lock_killable(mm)) {
 		mmput(mm);
+		put_task_struct(priv->task);
+		priv->task = NULL;
 		return ERR_PTR(-EINTR);
 	}
 
-	/* start the next element from addr */
-	vma = find_vma(mm, addr);
-	if (vma)
-		return vma;
+	vma_iter_init(&priv->iter, mm, last_addr);
 
-	mmap_read_unlock(mm);
-	mmput(mm);
-	return NULL;
+	return proc_get_vma(priv, ppos);
 }
 
-static void m_stop(struct seq_file *m, void *_vml)
+static void m_stop(struct seq_file *m, void *v)
 {
 	struct proc_maps_private *priv = m->private;
+	struct mm_struct *mm = priv->lock_ctx.mm;
 
-	if (!IS_ERR_OR_NULL(_vml)) {
-		mmap_read_unlock(priv->mm);
-		mmput(priv->mm);
-	}
-	if (priv->task) {
-		put_task_struct(priv->task);
-		priv->task = NULL;
-	}
+	if (!priv->task)
+		return;
+
+	mmap_read_unlock(mm);
+	mmput(mm);
+	put_task_struct(priv->task);
+	priv->task = NULL;
 }
 
-static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
+static void *m_next(struct seq_file *m, void *_p, loff_t *ppos)
 {
-	struct vm_area_struct *vma = _p;
-
-	*pos = vma->vm_end;
-	return find_vma(vma->vm_mm, vma->vm_end);
+	return proc_get_vma(m->private, ppos);
 }
 
 static const struct seq_operations proc_pid_maps_ops = {
@@ -262,9 +259,9 @@ static int maps_open(struct inode *inode, struct file *file,
 		return -ENOMEM;
 
 	priv->inode = inode;
-	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
-	if (IS_ERR(priv->mm)) {
-		int err = PTR_ERR(priv->mm);
+	priv->lock_ctx.mm = proc_mem_open(inode, PTRACE_MODE_READ);
+	if (IS_ERR_OR_NULL(priv->lock_ctx.mm)) {
+		int err = priv->lock_ctx.mm ? PTR_ERR(priv->lock_ctx.mm) : -ESRCH;
 
 		seq_release_private(inode, file);
 		return err;
@@ -279,8 +276,8 @@ static int map_release(struct inode *inode, struct file *file)
 	struct seq_file *seq = file->private_data;
 	struct proc_maps_private *priv = seq->private;
 
-	if (priv->mm)
-		mmdrop(priv->mm);
+	if (priv->lock_ctx.mm)
+		mmdrop(priv->lock_ctx.mm);
 
 	return seq_release_private(inode, file);
 }