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authorOleg Nesterov <oleg@redhat.com>2014-10-09 15:25:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-09 22:25:49 -0400
commit27692cd56e2aa6924b49f4361247d707a023484a (patch)
tree285d080f84f97f4cf46e90522b6121bf9dac84c0 /fs/proc/task_nommu.c
parentce34fddb5bafb424a4aaa9f403feb7dbe776c7d1 (diff)
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>
Diffstat (limited to 'fs/proc/task_nommu.c')
-rw-r--r--fs/proc/task_nommu.c32
1 files changed, 26 insertions, 6 deletions
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index 98c95d2833ea..9019f1de3f72 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -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,
};