diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index fef39894846266d23bc96ba4871551e43c2c9a1e..c7228c2326d106e15a64d8fc72bd3e2b215f1edc 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -146,13 +146,24 @@ m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma) return vma->vm_next ?: priv->tail_vma; } +static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma) +{ + if (m->count < m->size) /* vma is copied successfully */ + m->version = m_next_vma(m->private, vma) ? vma->vm_start : -1UL; +} + static void *m_start(struct seq_file *m, loff_t *ppos) { struct proc_maps_private *priv = m->private; + unsigned long last_addr = m->version; struct mm_struct *mm; struct vm_area_struct *vma; unsigned int pos = *ppos; + /* See m_cache_vma(). Zero at the start or after lseek. */ + if (last_addr == -1UL) + return NULL; + priv->task = get_pid_task(priv->pid, PIDTYPE_PID); if (!priv->task) return ERR_PTR(-ESRCH); @@ -165,6 +176,13 @@ static void *m_start(struct seq_file *m, loff_t *ppos) hold_task_mempolicy(priv); priv->tail_vma = get_gate_vma(mm); + if (last_addr) { + vma = find_vma(mm, last_addr); + if (vma && (vma = m_next_vma(priv, vma))) + return vma; + } + + m->version = 0; if (pos < mm->map_count) { for (vma = mm->mmap; pos; pos--) vma = vma->vm_next; @@ -340,6 +358,7 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid) static int show_map(struct seq_file *m, void *v, int is_pid) { show_map_vma(m, v, is_pid); + m_cache_vma(m, v); return 0; } @@ -617,6 +636,7 @@ static int show_smap(struct seq_file *m, void *v, int is_pid) mss.nonlinear >> 10); show_smap_vma_flags(m, vma); + m_cache_vma(m, vma); return 0; } @@ -1471,6 +1491,7 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid) seq_printf(m, " N%d=%lu", nid, md->node[nid]); out: seq_putc(m, '\n'); + m_cache_vma(m, vma); return 0; }