This fixes the last couple of pid struct locking failures I know about.
Goes on top of the other -mm patches for pid struct locking in the tty
layer
Signed-off-by: Alan Cox <alan@redhat.com>
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.25-rc2-mm1/drivers/char/tty_io.c linux-2.6.25-rc2-mm1/drivers/char/tty_io.c
--- linux.vanilla-2.6.25-rc2-mm1/drivers/char/tty_io.c 2008-02-19 11:03:26.000000000 +0000
+++ linux-2.6.25-rc2-mm1/drivers/char/tty_io.c 2008-02-25 09:29:22.000000000 +0000
@@ -3098,6 +3260,27 @@
}
/**
+ * tty_get_pgrp - return a ref counted pgrp pid
+ * @tty: tty to read
+ *
+ * Returns a refcounted instance of the pid struct for the process
+ * group controlling the tty.
+ */
+
+struct pid *tty_get_pgrp(struct tty_struct *tty)
+{
+ unsigned long flags;
+ struct pid *pgrp;
+
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ pgrp = get_pid(tty->pgrp);
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+ return pgrp;
+}
+EXPORT_SYMBOL_GPL(tty_get_pgrp);
+
+/**
* tiocgpgrp - get process group
* @tty: tty passed by user
* @real_tty: tty side of the tty pased by the user if a pty else the tty
@@ -3111,13 +3294,18 @@
static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
{
+ struct pid *pid;
+ int ret;
/*
* (tty == real_tty) is a cheap way of
* testing if the tty is NOT a master pty.
*/
if (tty == real_tty && current->signal->tty != real_tty)
return -ENOTTY;
- return put_user(pid_vnr(real_tty->pgrp), p);
+ pid = tty_get_pgrp(real_tty);
+ ret = put_user(pid_vnr(pid), p);
+ put_pid(pid);
+ return ret;
}
/**
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.25-rc2-mm1/fs/proc/array.c linux-2.6.25-rc2-mm1/fs/proc/array.c
--- linux.vanilla-2.6.25-rc2-mm1/fs/proc/array.c 2008-02-19 11:03:02.000000000 +0000
+++ linux-2.6.25-rc2-mm1/fs/proc/array.c 2008-02-25 09:28:29.000000000 +0000
@@ -408,6 +408,7 @@
unsigned long rsslim = 0;
char tcomm[sizeof(task->comm)];
unsigned long flags;
+ struct pid *pgrp;
state = *get_task_state(task);
vsize = eip = esp = 0;
@@ -430,7 +431,9 @@
struct signal_struct *sig = task->signal;
if (sig->tty) {
- tty_pgrp = pid_nr_ns(sig->tty->pgrp, ns);
+ pgrp = tty_get_pgrp(sig->tty);
+ tty_pgrp = pid_nr_ns(pgrp, ns);
+ put_pid(pgrp);
tty_nr = new_encode_dev(tty_devnum(sig->tty));
}
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.25-rc2-mm1/include/linux/tty.h linux-2.6.25-rc2-mm1/include/linux/tty.h
--- linux.vanilla-2.6.25-rc2-mm1/include/linux/tty.h 2008-02-19 11:03:27.000000000 +0000
+++ linux-2.6.25-rc2-mm1/include/linux/tty.h 2008-02-25 09:27:37.000000000 +0000
@@ -295,6 +315,7 @@
extern void tty_write_message(struct tty_struct *tty, char *msg);
extern int is_current_pgrp_orphaned(void);
+extern struct pid *tty_get_pgrp(struct tty_struct *tty);
extern int is_ignored(int sig);
extern int tty_signal(int sig, struct tty_struct *tty);
extern void tty_hangup(struct tty_struct * tty);
--
