svn commit: r196197 - in stable/7/sys: . contrib/pf fs/unionfs kern

[John Baldwin]

Author: jhb
Date: Thu Aug 13 17:51:26 2009
New Revision: 196197
URL: http://svn.freebsd.org/changeset/base/196197

Log:
  MFC: Fix some LORs between vnode locks and filedescriptor table locks.
  - Don't grab the filedesc lock just to read fd_cmask.
  - Drop vnode locks earlier when mounting the root filesystem and before
    sanitizing stdin/out/err file descriptors during execve().

Modified:
  stable/7/sys/   (props changed)
  stable/7/sys/contrib/pf/   (props changed)
  stable/7/sys/fs/unionfs/union_subr.c
  stable/7/sys/kern/kern_exec.c
  stable/7/sys/kern/vfs_mount.c
  stable/7/sys/kern/vfs_syscalls.c

Modified: stable/7/sys/fs/unionfs/union_subr.c
==============================================================================
--- stable/7/sys/fs/unionfs/union_subr.c	Thu Aug 13 17:09:45 2009	(r196196)
+++ stable/7/sys/fs/unionfs/union_subr.c	Thu Aug 13 17:51:26 2009	(r196197)
@@ -488,9 +488,7 @@ unionfs_create_uppervattr_core(struct un
 		}
 		break;
 	default:		/* UNIONFS_TRADITIONAL */
-		FILEDESC_SLOCK(td->td_proc->p_fd);
 		uva->va_mode = 0777 & ~td->td_proc->p_fd->fd_cmask;
-		FILEDESC_SUNLOCK(td->td_proc->p_fd);
 		uva->va_uid = ump->um_uid;
 		uva->va_gid = ump->um_gid;
 		break;

Modified: stable/7/sys/kern/kern_exec.c
==============================================================================
--- stable/7/sys/kern/kern_exec.c	Thu Aug 13 17:09:45 2009	(r196196)
+++ stable/7/sys/kern/kern_exec.c	Thu Aug 13 17:51:26 2009	(r196197)
@@ -615,8 +615,8 @@ interpret:
 		 * allocate memory, so temporarily drop the process lock.
 		 */
 		PROC_UNLOCK(p);
-		setugidsafety(td);
 		VOP_UNLOCK(imgp->vp, 0, td);
+		setugidsafety(td);
 		error = fdcheckstd(td);
 		vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY, td);
 		if (error != 0)

Modified: stable/7/sys/kern/vfs_mount.c
==============================================================================
--- stable/7/sys/kern/vfs_mount.c	Thu Aug 13 17:09:45 2009	(r196196)
+++ stable/7/sys/kern/vfs_mount.c	Thu Aug 13 17:51:26 2009	(r196197)
@@ -1083,9 +1083,10 @@ vfs_domount(
 		vfs_event_signal(NULL, VQ_MOUNT, 0);
 		if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp, td))
 			panic("mount: lost mount");
-		mountcheckdirs(vp, newdp);
-		vput(newdp);
+		VOP_UNLOCK(newdp, 0, td);
 		VOP_UNLOCK(vp, 0, td);
+		mountcheckdirs(vp, newdp);
+		vrele(newdp);
 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
 			error = vfs_allocate_syncvnode(mp);
 		vfs_unbusy(mp, td);
@@ -1468,8 +1469,10 @@ set_rootvnode(struct thread *td)
 	if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode, td))
 		panic("Cannot find root vnode");
 
+	VOP_UNLOCK(rootvnode, 0, td);
+
 	p = td->td_proc;
-	FILEDESC_SLOCK(p->p_fd);
+	FILEDESC_XLOCK(p->p_fd);
 
 	if (p->p_fd->fd_cdir != NULL)
 		vrele(p->p_fd->fd_cdir);
@@ -1481,9 +1484,7 @@ set_rootvnode(struct thread *td)
 	p->p_fd->fd_rdir = rootvnode;
 	VREF(rootvnode);
 
-	FILEDESC_SUNLOCK(p->p_fd);
-
-	VOP_UNLOCK(rootvnode, 0, td);
+	FILEDESC_XUNLOCK(p->p_fd);
 }
 
 /*

Modified: stable/7/sys/kern/vfs_syscalls.c
==============================================================================
--- stable/7/sys/kern/vfs_syscalls.c	Thu Aug 13 17:09:45 2009	(r196196)
+++ stable/7/sys/kern/vfs_syscalls.c	Thu Aug 13 17:51:26 2009	(r196197)
@@ -1238,10 +1238,8 @@ restart:
 		return (EEXIST);
 	} else {
 		VATTR_NULL(&vattr);
-		FILEDESC_SLOCK(td->td_proc->p_fd);
 		vattr.va_mode = (mode & ALLPERMS) &
 		    ~td->td_proc->p_fd->fd_cmask;
-		FILEDESC_SUNLOCK(td->td_proc->p_fd);
 		vattr.va_rdev = dev;
 		whiteout = 0;
 
@@ -1351,9 +1349,7 @@ restart:
 	}
 	VATTR_NULL(&vattr);
 	vattr.va_type = VFIFO;
-	FILEDESC_SLOCK(td->td_proc->p_fd);
 	vattr.va_mode = (mode & ALLPERMS) & ~td->td_proc->p_fd->fd_cmask;
-	FILEDESC_SUNLOCK(td->td_proc->p_fd);
 #ifdef MAC
 	error = mac_check_vnode_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
 	    &vattr);
@@ -1564,9 +1560,7 @@ restart:
 		goto restart;
 	}
 	VATTR_NULL(&vattr);
-	FILEDESC_SLOCK(td->td_proc->p_fd);
 	vattr.va_mode = ACCESSPERMS &~ td->td_proc->p_fd->fd_cmask;
-	FILEDESC_SUNLOCK(td->td_proc->p_fd);
 #ifdef MAC
 	vattr.va_type = VLNK;
 	error = mac_check_vnode_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
@@ -3502,9 +3496,7 @@ restart:
 	}
 	VATTR_NULL(&vattr);
 	vattr.va_type = VDIR;
-	FILEDESC_SLOCK(td->td_proc->p_fd);
 	vattr.va_mode = (mode & ACCESSPERMS) &~ td->td_proc->p_fd->fd_cmask;
-	FILEDESC_SUNLOCK(td->td_proc->p_fd);
 #ifdef MAC
 	error = mac_check_vnode_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
 	    &vattr);