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Commit a03fcb73 authored by Cedric Le Goater's avatar Cedric Le Goater Committed by Linus Torvalds
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[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: default avatarCedric Le Goater <clg@fr.ibm.com>
Acked-by: default avatarEric Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent f40f50d3

ipc/mqueue.c

+15 −12
Original line number Diff line number Diff line
@@ -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);
@@ -518,7 +518,7 @@ 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,

			kill_pid_info(info->notify.sigev_signo,

				      &sig_i, info->notify_owner);

			break;

		case SIGEV_THREAD:
@@ -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 @@ asmlinkage long sys_mq_notify(mqd_t mqdes, 
	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 @@ asmlinkage long sys_mq_notify(mqd_t mqdes, 
			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);