Commit 23d54837 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds

fs/proc/task_mmu.c: cleanup the "tail_vma" horror in m_next()

1. Kill the first "vma != NULL" check. Firstly this is not possible,
   m_next() won't be called if ->start() or the previous ->next()
   returns NULL.

   And if it was possible the 2nd "vma != tail_vma" check is buggy,
   we should not wrongly return ->tail_vma.

2. Make this function readable. The logic is very simple, we should
   return check "vma != tail" once and return "vm_next || tail_vma".
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: default avatarCyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 59b4bf12
...@@ -210,15 +210,13 @@ static void *m_start(struct seq_file *m, loff_t *pos) ...@@ -210,15 +210,13 @@ static void *m_start(struct seq_file *m, loff_t *pos)
static void *m_next(struct seq_file *m, void *v, loff_t *pos) static void *m_next(struct seq_file *m, void *v, loff_t *pos)
{ {
struct proc_maps_private *priv = m->private; struct proc_maps_private *priv = m->private;
struct vm_area_struct *vma = v;
struct vm_area_struct *tail_vma = priv->tail_vma; struct vm_area_struct *tail_vma = priv->tail_vma;
struct vm_area_struct *next; struct vm_area_struct *vma = v, *next = NULL;
(*pos)++; (*pos)++;
if (vma && (vma != tail_vma) && vma->vm_next) if (vma != tail_vma)
return vma->vm_next; next = vma->vm_next ?: tail_vma;
next = (vma != tail_vma) ? tail_vma : NULL;
if (!next) if (!next)
vma_stop(priv); vma_stop(priv);
return next; return next;
......
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