Author: kib
Date: Mon Jun 8 13:34:45 2009
New Revision: 193714
URL: http://svn.freebsd.org/changeset/base/193714
Log:
Do not dereference vp->v_rdev without holding any of dev_mtx or vnode
lock. Use code similar to devfs_fp_check(), but inlined to feet other
checks performed by ttyhook_register().
Reviewed by: ed
Modified:
head/sys/kern/tty.c
Modified: head/sys/kern/tty.c
==============================================================================
--- head/sys/kern/tty.c Mon Jun 8 13:31:27 2009 (r193713)
+++ head/sys/kern/tty.c Mon Jun 8 13:34:45 2009 (r193714)
@@ -1742,19 +1742,31 @@ ttyhook_register(struct tty **rtp, struc
goto done1;
}
- /* Make sure the vnode is bound to a character device. */
- error = EINVAL;
- if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR ||
- fp->f_vnode->v_rdev == NULL)
+ /*
+ * Make sure the vnode is bound to a character device.
+ * Unlocked check for the vnode type is ok there, because we
+ * only shall prevent calling devvn_refthread on the file that
+ * never has been opened over a character device.
+ */
+ if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
+ error = EINVAL;
goto done1;
- dev = fp->f_vnode->v_rdev;
+ }
/* Make sure it is a TTY. */
- cdp = dev_refthread(dev);
- if (cdp == NULL)
+ cdp = devvn_refthread(fp->f_vnode, &dev);
+ if (cdp == NULL) {
+ error = ENXIO;
goto done1;
- if (cdp != &ttydev_cdevsw)
+ }
+ if (dev != fp->f_data) {
+ error = ENXIO;
goto done2;
+ }
+ if (cdp != &ttydev_cdevsw) {
+ error = ENOTTY;
+ goto done2;
+ }
tp = dev->si_drv1;
/* Try to attach the hook to the TTY. */
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
