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-rw-r--r--fs/proc/proc_sysctl.c17
1 files changed, 16 insertions, 1 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index a7708b7c957f..47b474b572c1 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -525,20 +525,32 @@ static ssize_t proc_sys_write(struct file *filp, const char __user *buf,
static int proc_sys_open(struct inode *inode, struct file *filp)
{
+ struct ctl_table_header *head = grab_header(inode);
struct ctl_table *table = PROC_I(inode)->sysctl_entry;
+ /* sysctl was unregistered */
+ if (IS_ERR(head))
+ return PTR_ERR(head);
+
if (table->poll)
filp->private_data = proc_sys_poll_event(table->poll);
+ sysctl_head_finish(head);
+
return 0;
}
static unsigned int proc_sys_poll(struct file *filp, poll_table *wait)
{
struct inode *inode = filp->f_path.dentry->d_inode;
+ struct ctl_table_header *head = grab_header(inode);
struct ctl_table *table = PROC_I(inode)->sysctl_entry;
- unsigned long event = (unsigned long)filp->private_data;
unsigned int ret = DEFAULT_POLLMASK;
+ unsigned long event;
+
+ /* sysctl was unregistered */
+ if (IS_ERR(head))
+ return POLLERR | POLLHUP;
if (!table->proc_handler)
goto out;
@@ -546,6 +558,7 @@ static unsigned int proc_sys_poll(struct file *filp, poll_table *wait)
if (!table->poll)
goto out;
+ event = (unsigned long)filp->private_data;
poll_wait(filp, &table->poll->wait, wait);
if (event != atomic_read(&table->poll->event)) {
@@ -554,6 +567,8 @@ static unsigned int proc_sys_poll(struct file *filp, poll_table *wait)
}
out:
+ sysctl_head_finish(head);
+
return ret;
}