[PATCH] update mq_notify to use a struct pid

Message queues can signal a process waiting for a message.

This patch replaces the pid_t value with a struct pid to avoid pid wrap
around problems.

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Cedric Le Goater 2006-10-02 02:17:26 -07:00 committed by Linus Torvalds
parent f40f50d3bb
commit a03fcb730b

View file

@ -73,7 +73,7 @@ struct mqueue_inode_info {
struct mq_attr attr;
struct sigevent notify;
pid_t notify_owner;
struct pid* notify_owner;
struct user_struct *user; /* user who created, for accounting */
struct sock *notify_sock;
struct sk_buff *notify_cookie;
@ -134,7 +134,7 @@ static struct inode *mqueue_get_inode(struct super_block *sb, int mode,
INIT_LIST_HEAD(&info->e_wait_q[0].list);
INIT_LIST_HEAD(&info->e_wait_q[1].list);
info->messages = NULL;
info->notify_owner = 0;
info->notify_owner = NULL;
info->qsize = 0;
info->user = NULL; /* set when all is ok */
memset(&info->attr, 0, sizeof(info->attr));
@ -338,7 +338,7 @@ static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
(info->notify_owner &&
info->notify.sigev_notify == SIGEV_SIGNAL) ?
info->notify.sigev_signo : 0,
info->notify_owner);
pid_nr(info->notify_owner));
spin_unlock(&info->lock);
buffer[sizeof(buffer)-1] = '\0';
slen = strlen(buffer)+1;
@ -363,7 +363,7 @@ static int mqueue_flush_file(struct file *filp, fl_owner_t id)
struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode);
spin_lock(&info->lock);
if (current->tgid == info->notify_owner)
if (task_tgid(current) == info->notify_owner)
remove_notification(info);
spin_unlock(&info->lock);
@ -518,8 +518,8 @@ static void __do_notify(struct mqueue_inode_info *info)
sig_i.si_pid = current->tgid;
sig_i.si_uid = current->uid;
kill_proc_info(info->notify.sigev_signo,
&sig_i, info->notify_owner);
kill_pid_info(info->notify.sigev_signo,
&sig_i, info->notify_owner);
break;
case SIGEV_THREAD:
set_cookie(info->notify_cookie, NOTIFY_WOKENUP);
@ -528,7 +528,8 @@ static void __do_notify(struct mqueue_inode_info *info)
break;
}
/* after notification unregisters process */
info->notify_owner = 0;
put_pid(info->notify_owner);
info->notify_owner = NULL;
}
wake_up(&info->wait_q);
}
@ -566,12 +567,13 @@ static long prepare_timeout(const struct timespec __user *u_arg)
static void remove_notification(struct mqueue_inode_info *info)
{
if (info->notify_owner != 0 &&
if (info->notify_owner != NULL &&
info->notify.sigev_notify == SIGEV_THREAD) {
set_cookie(info->notify_cookie, NOTIFY_REMOVED);
netlink_sendskb(info->notify_sock, info->notify_cookie, 0);
}
info->notify_owner = 0;
put_pid(info->notify_owner);
info->notify_owner = NULL;
}
static int mq_attr_ok(struct mq_attr *attr)
@ -1062,11 +1064,11 @@ retry:
ret = 0;
spin_lock(&info->lock);
if (u_notification == NULL) {
if (info->notify_owner == current->tgid) {
if (info->notify_owner == task_tgid(current)) {
remove_notification(info);
inode->i_atime = inode->i_ctime = CURRENT_TIME;
}
} else if (info->notify_owner != 0) {
} else if (info->notify_owner != NULL) {
ret = -EBUSY;
} else {
switch (notification.sigev_notify) {
@ -1086,7 +1088,8 @@ retry:
info->notify.sigev_notify = SIGEV_SIGNAL;
break;
}
info->notify_owner = current->tgid;
info->notify_owner = get_pid(task_tgid(current));
inode->i_atime = inode->i_ctime = CURRENT_TIME;
}
spin_unlock(&info->lock);