diff options
| -rw-r--r-- | fs/proc/proc_sysctl.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index a7708b7c957..47b474b572c 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; } |