[rtems commit] libcsupport: Accept NULL for zero-length entries

[Sebastian Huber]

Module:    rtems
Branch:    master
Commit:    c1d8ee4cdc094b3595d2f4d0cdfc17a53f85716c
Changeset: http://git.rtems.org/rtems/commit/?id=c1d8ee4cdc094b3595d2f4d0cdfc17a53f85716c

Author:    Sebastian Huber <sebastian.huber at embedded-brains.de>
Date:      Tue Dec 17 10:59:13 2013 +0100

libcsupport: Accept NULL for zero-length entries

---

 cpukit/libcsupport/include/rtems/libio_.h  |    2 +-
 cpukit/libfs/src/defaults/default_readv.c  |   24 ++++++++++++++----------
 cpukit/libfs/src/defaults/default_writev.c |   24 ++++++++++++++----------
 testsuites/psxtests/psxrdwrv/test.c        |    4 ++--
 4 files changed, 31 insertions(+), 23 deletions(-)

diff --git a/cpukit/libcsupport/include/rtems/libio_.h b/cpukit/libcsupport/include/rtems/libio_.h
index 995d621..78a57c8 100644
--- a/cpukit/libcsupport/include/rtems/libio_.h
+++ b/cpukit/libcsupport/include/rtems/libio_.h
@@ -887,7 +887,7 @@ static inline ssize_t rtems_libio_iovec_eval(
 
     total += ( ssize_t ) len;
 
-    if ( iov[ v ].iov_base == NULL ) {
+    if ( iov[ v ].iov_base == NULL && len != 0 ) {
       rtems_set_errno_and_return_minus_one( EINVAL );
     }
   }
diff --git a/cpukit/libfs/src/defaults/default_readv.c b/cpukit/libfs/src/defaults/default_readv.c
index 063ed5e..0156a41 100644
--- a/cpukit/libfs/src/defaults/default_readv.c
+++ b/cpukit/libfs/src/defaults/default_readv.c
@@ -41,19 +41,23 @@ ssize_t rtems_filesystem_default_readv(
   total = 0;
 
   for ( v = 0 ; v < iovcnt ; ++v ) {
-    ssize_t bytes = ( *iop->pathinfo.handlers->read_h )(
-      iop,
-      iov[ v ].iov_base,
-      iov[ v ].iov_len
-    );
+    size_t len = iov[ v ].iov_len;
 
-    if ( bytes < 0 )
-      return -1;
+    if ( len > 0 ) {
+      ssize_t bytes = ( *iop->pathinfo.handlers->read_h )(
+        iop,
+        iov[ v ].iov_base,
+        len
+      );
 
-    total += bytes;
+      if ( bytes < 0 )
+        return -1;
 
-    if ( bytes != iov[ v ].iov_len )
-      break;
+      total += bytes;
+
+      if ( bytes != ( ssize_t ) len )
+        break;
+    }
   }
 
   return total;
diff --git a/cpukit/libfs/src/defaults/default_writev.c b/cpukit/libfs/src/defaults/default_writev.c
index e62e084..3a4ed82 100644
--- a/cpukit/libfs/src/defaults/default_writev.c
+++ b/cpukit/libfs/src/defaults/default_writev.c
@@ -41,19 +41,23 @@ ssize_t rtems_filesystem_default_writev(
   total = 0;
 
   for ( v = 0 ; v < iovcnt ; ++v ) {
-    ssize_t bytes = ( *iop->pathinfo.handlers->write_h )(
-      iop,
-      iov[ v ].iov_base,
-      iov[ v ].iov_len
-    );
+    size_t len = iov[ v ].iov_len;
 
-    if ( bytes < 0 )
-      return -1;
+    if ( len > 0 ) {
+      ssize_t bytes = ( *iop->pathinfo.handlers->write_h )(
+        iop,
+        iov[ v ].iov_base,
+        len
+      );
 
-    total += bytes;
+      if ( bytes < 0 )
+        return -1;
 
-    if ( bytes != iov[ v ].iov_len )
-      break;
+      total += bytes;
+
+      if ( bytes != ( ssize_t ) len )
+        break;
+    }
   }
 
   return total;
diff --git a/testsuites/psxtests/psxrdwrv/test.c b/testsuites/psxtests/psxrdwrv/test.c
index 0e06674..181d9d4 100644
--- a/testsuites/psxtests/psxrdwrv/test.c
+++ b/testsuites/psxtests/psxrdwrv/test.c
@@ -361,7 +361,7 @@ int doErrorTest(void)
   /*  writev --  all zero length buffers */
   vec[0].iov_base = vec;
   vec[0].iov_len = 0;
-  vec[1].iov_base = vec;
+  vec[1].iov_base = NULL;
   vec[1].iov_len = 0;
   puts("writev iov_len works with no effect -- OK");
   rc = writev(fd, vec, 2);
@@ -374,7 +374,7 @@ int doErrorTest(void)
   /*  readv --  all zero length buffers */
   vec[0].iov_base = vec;
   vec[0].iov_len = 0;
-  vec[1].iov_base = vec;
+  vec[1].iov_base = NULL;
   vec[1].iov_len = 0;
   puts("readv iov_len works with no effect -- OK");
   rc = readv(fd, vec, 2);