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Diffstat (limited to 'fs/proc/task_nommu.c')
-rw-r--r--fs/proc/task_nommu.c88
1 files changed, 61 insertions, 27 deletions
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index 678455d2d683..599ec2e20104 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -123,6 +123,25 @@ unsigned long task_statm(struct mm_struct *mm,
return size;
}
+static pid_t pid_of_stack(struct proc_maps_private *priv,
+ struct vm_area_struct *vma, bool is_pid)
+{
+ struct inode *inode = priv->inode;
+ struct task_struct *task;
+ pid_t ret = 0;
+
+ rcu_read_lock();
+ task = pid_task(proc_pid(inode), PIDTYPE_PID);
+ if (task) {
+ task = task_of_stack(task, vma, is_pid);
+ if (task)
+ ret = task_pid_nr_ns(task, inode->i_sb->s_fs_info);
+ }
+ rcu_read_unlock();
+
+ return ret;
+}
+
/*
* display a single VMA to a sequenced file
*/
@@ -163,7 +182,7 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma,
seq_pad(m, ' ');
seq_path(m, &file->f_path, "");
} else if (mm) {
- pid_t tid = vm_is_stack(priv->task, vma, is_pid);
+ pid_t tid = pid_of_stack(priv, vma, is_pid);
if (tid != 0) {
seq_pad(m, ' ');
@@ -212,22 +231,22 @@ static void *m_start(struct seq_file *m, loff_t *pos)
loff_t n = *pos;
/* pin the task and mm whilst we play with them */
- priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
+ priv->task = get_proc_task(priv->inode);
if (!priv->task)
return ERR_PTR(-ESRCH);
- mm = mm_access(priv->task, PTRACE_MODE_READ);
- if (!mm || IS_ERR(mm)) {
- put_task_struct(priv->task);
- priv->task = NULL;
- return mm;
- }
- down_read(&mm->mmap_sem);
+ mm = priv->mm;
+ if (!mm || !atomic_inc_not_zero(&mm->mm_users))
+ return NULL;
+ down_read(&mm->mmap_sem);
/* start from the Nth VMA */
for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
if (n-- == 0)
return p;
+
+ up_read(&mm->mmap_sem);
+ mmput(mm);
return NULL;
}
@@ -235,11 +254,13 @@ static void m_stop(struct seq_file *m, void *_vml)
{
struct proc_maps_private *priv = m->private;
+ if (!IS_ERR_OR_NULL(_vml)) {
+ up_read(&priv->mm->mmap_sem);
+ mmput(priv->mm);
+ }
if (priv->task) {
- struct mm_struct *mm = priv->task->mm;
- up_read(&mm->mmap_sem);
- mmput(mm);
put_task_struct(priv->task);
+ priv->task = NULL;
}
}
@@ -269,20 +290,33 @@ static int maps_open(struct inode *inode, struct file *file,
const struct seq_operations *ops)
{
struct proc_maps_private *priv;
- int ret = -ENOMEM;
-
- priv = kzalloc(sizeof(*priv), GFP_KERNEL);
- if (priv) {
- priv->pid = proc_pid(inode);
- ret = seq_open(file, ops);
- if (!ret) {
- struct seq_file *m = file->private_data;
- m->private = priv;
- } else {
- kfree(priv);
- }
+
+ priv = __seq_open_private(file, ops, sizeof(*priv));
+ if (!priv)
+ 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);
+
+ seq_release_private(inode, file);
+ return err;
}
- return ret;
+
+ return 0;
+}
+
+
+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);
+
+ return seq_release_private(inode, file);
}
static int pid_maps_open(struct inode *inode, struct file *file)
@@ -299,13 +333,13 @@ const struct file_operations proc_pid_maps_operations = {
.open = pid_maps_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = seq_release_private,
+ .release = map_release,
};
const struct file_operations proc_tid_maps_operations = {
.open = tid_maps_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = seq_release_private,
+ .release = map_release,
};