Changeset a55d5f9f in mainline for kernel

Timestamp:

2007-12-23T21:21:41Z (18 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

a92da0a

Parents:

654b7db

Message:

Add support for IPC_M_DATA_READ calls.

Location:

kernel/generic

Files:

• include/ipc/ipc.h (modified) (1 diff)
• src/ipc/ipc.c (modified) (1 diff)
• src/ipc/sysipc.c (modified) (3 diffs)

kernel/generic/include/ipc/ipc.h

@@ -280 +280 @@
         ipc_data_t data;
 
-        /** Buffer for IPC_M_DATA_SEND. */
+        /** Buffer for IPC_M_DATA_WRITE and IPC_M_DATA_READ. */
         uint8_t *buffer;
 } call_t;

kernel/generic/src/ipc/ipc.c

@@ -415 +415 @@
         while (!list_empty(lst)) {
                 call = list_get_instance(lst->next, call_t, link);
+                if (call->buffer)
+                        free(call->buffer);
                 list_remove(&call->link);
 

kernel/generic/src/ipc/sysipc.c

@@ -236 +236 @@
                         IPC_SET_RETVAL(answer->data, rc);
                 }
+        } else if (IPC_GET_METHOD(*olddata) == IPC_M_DATA_READ) {
+                ASSERT(!answer->buffer);
+                if (!IPC_GET_RETVAL(answer->data)) {
+                        /* The recipient agreed to send data. */
+                        uintptr_t src = IPC_GET_ARG1(answer->data);
+                        uintptr_t dst = IPC_GET_ARG1(*olddata);
+                        size_t max_size = IPC_GET_ARG2(*olddata);
+                        size_t size = IPC_GET_ARG2(answer->data);
+                        if (size <= max_size) {
+                                /*
+                                 * Copy the destination VA so that this piece of
+                                 * information is not lost.
+                                 */
+                                IPC_SET_ARG1(answer->data, dst);
+
+                                answer->buffer = malloc(size, 0);
+                                int rc = copy_from_uspace(answer->buffer,
+                                    (void *) src, size);
+                                if (rc) {
+                                        IPC_SET_RETVAL(answer->data, rc);
+                                        free(answer->buffer);
+                                        answer->buffer = NULL;
+                                }
+                        } else {
+                                IPC_SET_RETVAL(answer->data, ELIMIT);
+                        }
+                }
         } else if (IPC_GET_METHOD(*olddata) == IPC_M_DATA_WRITE) {
                 ASSERT(answer->buffer);
                 if (!IPC_GET_RETVAL(answer->data)) {
+                        /* The recipient agreed to receive data. */
                         int rc;
                         uintptr_t dst;
                         uintptr_t size;
+                        uintptr_t max_size;
 
                         dst = IPC_GET_ARG1(answer->data);
                         size = IPC_GET_ARG3(answer->data);
-
-                        rc = copy_to_uspace((void *) dst, answer->buffer, size);
-                        if (rc != 0)
-                                IPC_SET_RETVAL(answer->data, rc);
+                        max_size = IPC_GET_ARG3(*olddata);
+
+                        if (size <= max_size) {
+                                rc = copy_to_uspace((void *) dst,
+                                    answer->buffer, size);
+                                if (rc)
+                                        IPC_SET_RETVAL(answer->data, rc);
+                        } else {
+                                IPC_SET_RETVAL(answer->data, ELIMIT);
+                        }
                 }
                 free(answer->buffer);
@@ -285 +320 @@
                 IPC_SET_ARG2(call->data, size);
                 break;
+        case IPC_M_DATA_READ:
+                size = IPC_GET_ARG2(call->data);
+                if ((size <= 0 || (size > DATA_XFER_LIMIT)))
+                        return ELIMIT;
+                break;
         case IPC_M_DATA_WRITE:
                 src = IPC_GET_ARG2(call->data);
@@ -325 +365 @@
                         IPC_SET_ARG5(call->data, call->priv);
         }
+
+        if (call->buffer) {
+                /* This must be an affirmative answer to IPC_M_DATA_READ. */
+                uintptr_t dst = IPC_GET_ARG1(call->data);
+                size_t size = IPC_GET_ARG2(call->data);
+                int rc = copy_to_uspace((void *) dst, call->buffer, size);
+                if (rc)
+                        IPC_SET_RETVAL(call->data, rc);
+                free(call->buffer);
+                call->buffer = NULL;
+        }
 }