Changeset 390e987e in rtems for cpukit/libblock

Timestamp:

Sep 16, 2013, 8:43:30 AM (6 years ago)

Author:

Sebastian Huber <sebastian.huber@…>

Branches:

4.11, master

Children:

38d94f56

Parents:

a44917e

git-author:

Sebastian Huber <sebastian.huber@…> (09/16/13 08:43:30)

git-committer:

Sebastian Huber <sebastian.huber@…> (09/16/13 08:54:51)

Message:

libblock: PR2145: Limit maximum read-ahead blocks

This helps to prevent stack overflows due to configuration errors.

Location:

cpukit/libblock

Files:

• include/rtems/bdbuf.h (modified) (1 diff)
• src/bdbuf.c (modified) (3 diffs)

cpukit/libblock/include/rtems/bdbuf.h

@@ -461 +461 @@
  * @retval RTEMS_CALLED_FROM_ISR Called from an interrupt context.
  * @retval RTEMS_INVALID_NUMBER The buffer maximum is not an integral multiple
- * of the buffer minimum.
+ * of the buffer minimum.  The maximum read-ahead blocks count is too large.
  * @retval RTEMS_RESOURCE_IN_USE Already initialized.
  * @retval RTEMS_UNSATISFIED Not enough resources.

cpukit/libblock/src/bdbuf.c

@@ -1379 +1379 @@
 }
 
+static size_t
+rtems_bdbuf_read_request_size (uint32_t transfer_count)
+{
+  return sizeof (rtems_blkdev_request)
+    + sizeof (rtems_blkdev_sg_buffer) * transfer_count;
+}
+
 /**
  * Initialise the cache.
@@ -1404 +1411 @@
    * Check the configuration table values.
    */
+
   if ((bdbuf_config.buffer_max % bdbuf_config.buffer_min) != 0)
+    return RTEMS_INVALID_NUMBER;
+
+  if (rtems_bdbuf_read_request_size (bdbuf_config.max_read_ahead_blocks)
+      > RTEMS_MINIMUM_STACK_SIZE / 8U)
     return RTEMS_INVALID_NUMBER;
 
@@ -2078 +2090 @@
 #define bdbuf_alloc(size) __builtin_alloca (size)
 
-  req = bdbuf_alloc (sizeof (rtems_blkdev_request) +
-                     sizeof (rtems_blkdev_sg_buffer) * transfer_count);
+  req = bdbuf_alloc (rtems_bdbuf_read_request_size (transfer_count));
 
   req->req = RTEMS_BLKDEV_REQ_READ;