xnu-792.18.15.tar.gz

[apple/xnu.git] / bsd / kern / kern_subr.c

diff --git a/bsd/kern/kern_subr.c b/bsd/kern/kern_subr.c
index 0a40c0a19dca2f5bdc328ba8c808ee9822926fa1..c1f4ecf7c87fef14043fd9f0b3c457e7b7061eb7 100644 (file)
--- a/bsd/kern/kern_subr.c
+++ b/bsd/kern/kern_subr.c
@@ -1,14 +1,19 @@
 /*
  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
@@ -18,7 +23,7 @@
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
 /*
@@ -1056,7 +1061,7 @@ __private_extern__ void uio_calculateresid( uio_t a_uio )
                return;
        }
 
-       a_uio->uio_iovcnt = 0;
+       a_uio->uio_iovcnt = a_uio->uio_max_iovs;
        if (UIO_IS_64_BIT_SPACE(a_uio)) {
 #if 1 // LP64todo - remove this temp workaround once we go live with uio KPI
                a_uio->uio_resid = 0;
@@ -1065,7 +1070,6 @@ __private_extern__ void uio_calculateresid( uio_t a_uio )
 #endif
                for ( i = 0; i < a_uio->uio_max_iovs; i++ ) {
                        if (a_uio->uio_iovs.uiovp[i].iov_len != 0 && a_uio->uio_iovs.uiovp[i].iov_base != 0) {
-                               a_uio->uio_iovcnt++;
 #if 1 // LP64todo - remove this temp workaround once we go live with uio KPI
                                a_uio->uio_resid += a_uio->uio_iovs.uiovp[i].iov_len;
 #else
@@ -1073,16 +1077,32 @@ __private_extern__ void uio_calculateresid( uio_t a_uio )
 #endif
                        }
                }
+
+               /* position to first non zero length iovec (4235922) */
+               while (a_uio->uio_iovcnt > 0 && a_uio->uio_iovs.uiovp->iov_len == 0) {
+                       a_uio->uio_iovcnt--;
+                       if (a_uio->uio_iovcnt > 0) {
+                               a_uio->uio_iovs.uiovp++;
+                       }
+               }
        }
        else {
                a_uio->uio_resid = 0;
                for ( i = 0; i < a_uio->uio_max_iovs; i++ ) {
                        if (a_uio->uio_iovs.kiovp[i].iov_len != 0 && a_uio->uio_iovs.kiovp[i].iov_base != 0) {
-                               a_uio->uio_iovcnt++;
                                a_uio->uio_resid += a_uio->uio_iovs.kiovp[i].iov_len;
                        }
                }
+
+               /* position to first non zero length iovec (4235922) */
+               while (a_uio->uio_iovcnt > 0 && a_uio->uio_iovs.kiovp->iov_len == 0) {
+                       a_uio->uio_iovcnt--;
+                       if (a_uio->uio_iovcnt > 0) {
+                               a_uio->uio_iovs.kiovp++;
+                       }
+               }
        }
+
        return;
 }