xnu-792.24.17.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..ab64b242c73a8516403758f9647f85975aad1d8a 100644 (file)
--- a/bsd/kern/kern_subr.c
+++ b/bsd/kern/kern_subr.c
@@ -3,20 +3,19 @@
  *
  * @APPLE_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.
+ * The contents of this file constitute Original Code as defined in and
+ * are subject to the Apple Public Source License Version 1.1 (the
+ * "License").  You may not use this file except in compliance with the
+ * License.  Please obtain a copy of the License at
+ * http://www.apple.com/publicsource 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
+ * This Original Code and all software distributed under the License are
+ * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
  * 
  * @APPLE_LICENSE_HEADER_END@
  */
@@ -1056,7 +1055,7 @@ __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 +1064,6 @@ __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 +1071,32 @@ __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;
 }