Changeset f6bffee in mainline for kernel/generic/src/ipc/sysipc.c

Timestamp:

2011-04-06T20:19:04Z (14 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

55132b8, b910455

Parents:

b946bf83

Message:

Allow special flags that control processing of IPC_M_DATA_READ/WRITE in
the kernel:

• IPC_XF_NONE: default behavior
• IPC_XF_RESTRICT: restrict the transfer size if necessary

Make read() and write() use IPC_XF_RESTRICT.

File:

• kernel/generic/src/ipc/sysipc.c (modified) (2 diffs)

kernel/generic/src/ipc/sysipc.c

@@ -426 +426 @@
         case IPC_M_DATA_READ: {
                 size_t size = IPC_GET_ARG2(call->data);
-                if ((size <= 0 || (size > DATA_XFER_LIMIT)))
+                if (size <= 0)
                         return ELIMIT;
-                
+                if (size > DATA_XFER_LIMIT) {
+                        int flags = IPC_GET_ARG3(call->data);
+                        if (flags & IPC_XF_RESTRICT)
+                                IPC_SET_ARG2(call->data, DATA_XFER_LIMIT);
+                        else
+                                return ELIMIT;
+                }
                 break;
         }
@@ -435 +441 @@
                 size_t size = IPC_GET_ARG2(call->data);
                 
-                if (size > DATA_XFER_LIMIT)
-                        return ELIMIT;
+                if (size > DATA_XFER_LIMIT) {
+                        int flags = IPC_GET_ARG3(call->data);
+                        if (flags & IPC_XF_RESTRICT) {
+                                size = DATA_XFER_LIMIT;
+                                IPC_SET_ARG2(call->data, size);
+                        } else
+                                return ELIMIT;
+                }
                 
                 call->buffer = (uint8_t *) malloc(size, 0);