Changeset 91b60499 in mainline for kernel/generic/src/ipc/ops/conctmeto.c

Timestamp:

2017-09-30T06:29:42Z (7 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

300f4c4

Parents:

d076f16 (diff), 6636fb19 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge support for capabilities from lp:~jakub/helenos/caps

This commit introduces capabilities as task-local names for references to kernel
objects. Kernel objects are reference-counted wrappers for a select group of
objects allocated in and by the kernel that can be made accessible to userspace
in a controlled way via integer handles.

So far, a kernel object encapsulates either an irq_t or a phone_t.

Support for the former lead to the removal of kernel-assigned devnos and
unsecure deregistration of IRQs in which a random task was able to unregister
some other task's IRQ.

File:

• kernel/generic/src/ipc/ops/conctmeto.c (modified) (5 diffs)

kernel/generic/src/ipc/ops/conctmeto.c

@@ -1 +1 @@
 /*
  * Copyright (c) 2006 Ondrej Palkovsky
- * Copyright (c) 2012 Jakub Jermar 
+ * Copyright (c) 2012 Jakub Jermar
  * All rights reserved.
  *
@@ -42 +42 @@
 static int request_preprocess(call_t *call, phone_t *phone)
 {
-        int newphid = phone_alloc(TASK);
+        cap_handle_t phone_handle = phone_alloc(TASK);
 
-        /* Remember the phoneid or the error. */
-        call->priv = newphid;
-        if (newphid < 0)
-                return ELIMIT;
-                
+        /* Remember the phone capability or the error. */
+        call->priv = phone_handle;
+        if (phone_handle < 0)
+                return phone_handle;
+
         /* Set arg5 for server */
-        IPC_SET_ARG5(call->data, (sysarg_t) &TASK->phones[newphid]);
+        kobject_t *phone_obj = kobject_get(TASK, phone_handle,
+            KOBJECT_TYPE_PHONE);
+        /* Hand over phone_obj's reference to ARG5 */
+        IPC_SET_ARG5(call->data, (sysarg_t) phone_obj->phone);
 
         return EOK;
@@ -57 +60 @@
 static int request_forget(call_t *call)
 {
-        phone_dealloc(call->priv);
+        cap_handle_t phone_handle = (cap_handle_t) call->priv;
+        phone_dealloc(phone_handle);
+        /* Hand over reference from ARG5 to phone->kobject */
+        phone_t *phone = (phone_t *) IPC_GET_ARG5(call->data);
+        /* Drop phone_obj's reference */
+        kobject_put(phone->kobject);
         return EOK;
 }
@@ -63 +71 @@
 static int answer_preprocess(call_t *answer, ipc_data_t *olddata)
 {
+        /* Hand over reference from ARG5 to phone */
         phone_t *phone = (phone_t *) IPC_GET_ARG5(*olddata);
 
         /* If the user accepted call, connect */
-        if (IPC_GET_RETVAL(answer->data) == EOK)
+        if (IPC_GET_RETVAL(answer->data) == EOK) {
+                /* Hand over reference from phone to the answerbox */
                 (void) ipc_phone_connect(phone, &TASK->answerbox);
+        } else {
+                kobject_put(phone->kobject);
+        }
 
         return EOK;
@@ -74 +87 @@
 static int answer_process(call_t *answer)
 {
-        int newphid = (int) answer->priv;
+        cap_handle_t phone_handle = (cap_handle_t) answer->priv;
 
         if (IPC_GET_RETVAL(answer->data)) {
-                if (newphid >= 0) {
+                if (phone_handle >= 0) {
                         /*
                          * The phone was indeed allocated and now needs
                          * to be deallocated.
                          */
-                        phone_dealloc(newphid);
+                        phone_dealloc(phone_handle);
                 }
         } else {
-                IPC_SET_ARG5(answer->data, newphid);
+                IPC_SET_ARG5(answer->data, phone_handle);
         }