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Diffstat (limited to 'fs/proc/task_mmu.c')
-rw-r--r--fs/proc/task_mmu.c95
1 files changed, 31 insertions, 64 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 3ba9ae83bff5..8d382d4ec067 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -123,38 +123,14 @@ static void release_task_mempolicy(struct proc_maps_private *priv)
}
#endif
-static void vma_stop(struct proc_maps_private *priv)
-{
- struct mm_struct *mm = priv->mm;
-
- release_task_mempolicy(priv);
- up_read(&mm->mmap_sem);
- mmput(mm);
-}
-
-static struct vm_area_struct *
-m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
-{
- if (vma == priv->tail_vma)
- return NULL;
- 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_end : -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;
+ unsigned long last_addr = *ppos;
struct mm_struct *mm;
struct vm_area_struct *vma;
- unsigned int pos = *ppos;
- /* See m_cache_vma(). Zero at the start or after lseek. */
+ /* See m_next(). Zero at the start or after lseek. */
if (last_addr == -1UL)
return NULL;
@@ -163,64 +139,59 @@ static void *m_start(struct seq_file *m, loff_t *ppos)
return ERR_PTR(-ESRCH);
mm = priv->mm;
- if (!mm || !mmget_not_zero(mm))
+ if (!mm || !mmget_not_zero(mm)) {
+ put_task_struct(priv->task);
+ priv->task = NULL;
return NULL;
+ }
if (down_read_killable(&mm->mmap_sem)) {
mmput(mm);
+ put_task_struct(priv->task);
+ priv->task = NULL;
return ERR_PTR(-EINTR);
}
hold_task_mempolicy(priv);
priv->tail_vma = get_gate_vma(mm);
- if (last_addr) {
- vma = find_vma(mm, last_addr - 1);
- if (vma && vma->vm_start <= last_addr)
- vma = m_next_vma(priv, vma);
- if (vma)
- return vma;
- }
-
- m->version = 0;
- if (pos < mm->map_count) {
- for (vma = mm->mmap; pos; pos--) {
- m->version = vma->vm_start;
- vma = vma->vm_next;
- }
+ vma = find_vma(mm, last_addr);
+ if (vma)
return vma;
- }
-
- /* we do not bother to update m->version in this case */
- if (pos == mm->map_count && priv->tail_vma)
- return priv->tail_vma;
- vma_stop(priv);
- return NULL;
+ return priv->tail_vma;
}
-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 *ppos)
{
struct proc_maps_private *priv = m->private;
- struct vm_area_struct *next;
+ struct vm_area_struct *next, *vma = v;
+
+ if (vma == priv->tail_vma)
+ next = NULL;
+ else if (vma->vm_next)
+ next = vma->vm_next;
+ else
+ next = priv->tail_vma;
+
+ *ppos = next ? next->vm_start : -1UL;
- (*pos)++;
- next = m_next_vma(priv, v);
- if (!next)
- vma_stop(priv);
return next;
}
static void m_stop(struct seq_file *m, void *v)
{
struct proc_maps_private *priv = m->private;
+ struct mm_struct *mm = priv->mm;
- if (!IS_ERR_OR_NULL(v))
- vma_stop(priv);
- if (priv->task) {
- put_task_struct(priv->task);
- priv->task = NULL;
- }
+ if (!priv->task)
+ return;
+
+ release_task_mempolicy(priv);
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+ put_task_struct(priv->task);
+ priv->task = NULL;
}
static int proc_maps_open(struct inode *inode, struct file *file,
@@ -363,7 +334,6 @@ done:
static int show_map(struct seq_file *m, void *v)
{
show_map_vma(m, v);
- m_cache_vma(m, v);
return 0;
}
@@ -847,8 +817,6 @@ static int show_smap(struct seq_file *m, void *v)
seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma));
show_smap_vma_flags(m, vma);
- m_cache_vma(m, vma);
-
return 0;
}
@@ -1887,7 +1855,6 @@ static int show_numa_map(struct seq_file *m, void *v)
seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);
out:
seq_putc(m, '\n');
- m_cache_vma(m, vma);
return 0;
}