Messages in this thread Patch in this message | | | Date | Tue, 5 Aug 2014 21:47:03 +0200 | From | Oleg Nesterov <> | Subject | [PATCH v2 6/7] fs/proc/task_mmu.c: cleanup the "tail_vma" horror in m_next() |
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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: Oleg Nesterov <oleg@redhat.com> --- fs/proc/task_mmu.c | 8 +++----- 1 files changed, 3 insertions(+), 5 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index f1254b4..c4c8825 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -209,15 +209,13 @@ out: 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; - struct vm_area_struct *next; + struct vm_area_struct *vma = v, *next = NULL; (*pos)++; - if (vma && (vma != tail_vma) && vma->vm_next) - return vma->vm_next; + if (vma != tail_vma) + next = vma->vm_next ?: tail_vma; - next = (vma != tail_vma)? tail_vma: NULL; if (!next) vma_stop(priv); return next; -- 1.5.5.1
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