fs/proc/task_nommu.c: shift mm_access() from m_start() to proc_maps_open()

Copy-and-paste the changes from "fs/proc/task_mmu.c: shift mm_access()
from m_start() to proc_maps_open()" into task_nommu.c.

Change maps_open() to initialize priv->mm using proc_mem_open(), m_start()
can rely on atomic_inc_not_zero(mm_users) like task_mmu.c does.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2014-10-09 15:25:47 -07:00 committed by Linus Torvalds
parent ce34fddb5b
commit 27692cd56e
1 changed files with 26 additions and 6 deletions

View File

@ -216,11 +216,11 @@ static void *m_start(struct seq_file *m, loff_t *pos)
if (!priv->task)
return ERR_PTR(-ESRCH);
mm = mm_access(priv->task, PTRACE_MODE_READ);
if (!mm || IS_ERR(mm)) {
mm = priv->mm;
if (!mm || !atomic_inc_not_zero(&mm->mm_users)) {
put_task_struct(priv->task);
priv->task = NULL;
return mm;
return NULL;
}
down_read(&mm->mmap_sem);
@ -270,14 +270,34 @@ static int maps_open(struct inode *inode, struct file *file,
{
struct proc_maps_private *priv;
priv = __seq_open_private(file, ops, sizeof(struct proc_maps_private));
priv = __seq_open_private(file, ops, sizeof(*priv));
if (!priv)
return -ENOMEM;
priv->pid = proc_pid(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 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)
{
return maps_open(inode, file, &proc_pid_maps_ops);
@ -292,13 +312,13 @@ 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,
};