libcsupport: Accept NULL for zero-length entries

3 files changed, 29 insertions, 21 deletions

diff --git a/cpukit/libcsupport/include/rtems/libio_.h b/cpukit/libcsupport/include/rtems/libio_.h
index 995d621f79..78a57c8620 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 063ed5e678..0156a4138f 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 e62e084e72..3a4ed82c00 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;