From a03fcb730b4fe7da14ca4405f23dbde717b1d2b9 Mon Sep 17 00:00:00 2001 From: Cedric Le Goater Date: Mon, 2 Oct 2006 02:17:26 -0700 Subject: [PATCH] [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 Acked-by: Eric Biederman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- ipc/mqueue.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/ipc/mqueue.c b/ipc/mqueue.c index d75d0ba83360..c45ae86cec31 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -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); -- 2.20.1