Sufficient access checks are performed by vmapbuf() that calling

useracc() is pointless.  Remove the call to useracc() from physio().

Reviewed by:	tegge

1 files changed, 1 insertions, 15 deletions

diff --git a/sys/kern/kern_physio.c b/sys/kern/kern_physio.c
index aebbbdb..9a28936 100644
--- a/sys/kern/kern_physio.c
+++ b/sys/kern/kern_physio.c
@@ -88,25 +88,11 @@ physio(dev_t dev, struct uio *uio, int ioflag)
 
 			bp->b_blkno = btodb(bp->b_offset);
 
-			if (uio->uio_segflg == UIO_USERSPACE) {
-				/*
-				 * Note that useracc() alone is not a
-				 * sufficient test.  vmapbuf() can still fail
-				 * due to a smaller file mapped into a larger
-				 * area of VM, or if userland races against
-				 * vmapbuf() after the useracc() check.
-				 */
-				if (!useracc(bp->b_data, bp->b_bufsize,
-				    bp->b_iocmd == BIO_READ ?
-				    VM_PROT_WRITE : VM_PROT_READ)) {
-					error = EFAULT;
-					goto doerror;
-				}
+			if (uio->uio_segflg == UIO_USERSPACE)
 				if (vmapbuf(bp) < 0) {
 					error = EFAULT;
 					goto doerror;
 				}
-			}
 
 			DEV_STRATEGY(bp);
 			spl = splbio();