Changeset 01c3bb4 in mainline for kernel/generic/src/ipc/sysipc.c

Timestamp:

2017-11-25T15:43:25Z (6 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

ce4a21a0

Parents:

98cb5e0d

Message:

Convert call-handling syscalls to capabilities

This commit modifies the behavior of sys_ipc_wait_for_call() to return a
capability handle for requests. This capability handle can be used
either by sys_ipc_answer*() to answer the call or by sys_ipc_forward*()
to forward it further along. Answering or forwarding the call results in
destruction of the respective capability. For requests and
notifications, sys_ipc_wait_for_call() returns CAP_NIL and sets call
flags accordingly.

File:

• kernel/generic/src/ipc/sysipc.c (modified) (20 diffs)

kernel/generic/src/ipc/sysipc.c

@@ -53 +53 @@
 #include <print.h>
 #include <macros.h>
+#include <cap/cap.h>
 
 #define STRUCT_TO_USPACE(dst, src)  copy_to_uspace((dst), (src), sizeof(*(src)))
@@ -447 +448 @@
  * Common code for both the fast and the slow version.
  *
- * @param callid   Hash of the call to forward.
- * @param handle   Phone capability to use for forwarding.
+ * @param chandle  Call handle of the forwarded call.
+ * @param phandle  Phone handle to use for forwarding.
  * @param imethod  New interface and method to use for the forwarded call.
  * @param arg1     New value of the first argument for the forwarded call.
@@ -465 +466 @@
  *
  */
-static sysarg_t sys_ipc_forward_common(sysarg_t callid, sysarg_t handle,
+static sysarg_t sys_ipc_forward_common(sysarg_t chandle, sysarg_t phandle,
     sysarg_t imethod, sysarg_t arg1, sysarg_t arg2, sysarg_t arg3,
     sysarg_t arg4, sysarg_t arg5, unsigned int mode, bool slow)
 {
-        call_t *call = get_call(callid);
-        if (!call)
+        kobject_t *ckobj = cap_unpublish(TASK, chandle, KOBJECT_TYPE_CALL);
+        if (!ckobj)
                 return ENOENT;
         
+        call_t *call = ckobj->call;
+
         ipc_data_t old;
         bool need_old = answer_need_old(call);
@@ -481 +484 @@
         int rc;
 
-        kobject_t *kobj = kobject_get(TASK, handle, KOBJECT_TYPE_PHONE);
-        if (!kobj) {
+        kobject_t *pkobj = kobject_get(TASK, phandle, KOBJECT_TYPE_PHONE);
+        if (!pkobj) {
                 rc = ENOENT;
                 goto error;
@@ -528 +531 @@
         }
         
-        rc = ipc_forward(call, kobj->phone, &TASK->answerbox, mode);
+        rc = ipc_forward(call, pkobj->phone, &TASK->answerbox, mode);
         if (rc != EOK) {
                 after_forward = true;
@@ -534 +537 @@
         }
 
-        kobject_put(kobj);
+        cap_free(TASK, chandle);
+        kobject_put(ckobj);
+        kobject_put(pkobj);
         return EOK;
 
@@ -545 +550 @@
                 ipc_answer(&TASK->answerbox, call);
 
-        if (kobj)
-                kobject_put(kobj);
+        /* Republish the capability so that the call does not get lost. */
+        cap_publish(TASK, chandle, ckobj);
+
+        if (pkobj)
+                kobject_put(pkobj);
         return rc;
 }
@@ -559 +567 @@
  * arguments are not set and these values are ignored.
  *
- * @param callid   Hash of the call to forward.
- * @param handle   Phone handle to use for forwarding.
+ * @param chandle  Call handle of the call to forward.
+ * @param phandle  Phone handle to use for forwarding.
  * @param imethod  New interface and method to use for the forwarded call.
  * @param arg1     New value of the first argument for the forwarded call.
@@ -569 +577 @@
  *
  */
-sysarg_t sys_ipc_forward_fast(sysarg_t callid, sysarg_t handle,
+sysarg_t sys_ipc_forward_fast(sysarg_t chandle, sysarg_t phandle,
     sysarg_t imethod, sysarg_t arg1, sysarg_t arg2, unsigned int mode)
 {
-        return sys_ipc_forward_common(callid, handle, imethod, arg1, arg2, 0, 0,
-            0, mode, false); 
+        return sys_ipc_forward_common(chandle, phandle, imethod, arg1, arg2, 0,
+            0, 0, mode, false);
 }
 
@@ -585 +593 @@
  * and arg5, respectively, to ARG3, ARG4 and ARG5, respectively.
  *
- * @param callid  Hash of the call to forward.
- * @param handle  Phone handle to use for forwarding.
- * @param data    Userspace address of the new IPC data.
- * @param mode    Flags that specify mode of the forward operation.
+ * @param chandle  Call handle of the call to forward.
+ * @param phandle  Phone handle to use for forwarding.
+ * @param data     Userspace address of the new IPC data.
+ * @param mode     Flags that specify mode of the forward operation.
  *
  * @return 0 on succes, otherwise an error code.
  *
  */
-sysarg_t sys_ipc_forward_slow(sysarg_t callid, sysarg_t handle,
+sysarg_t sys_ipc_forward_slow(sysarg_t chandle, sysarg_t phandle,
     ipc_data_t *data, unsigned int mode)
 {
@@ -602 +610 @@
                 return (sysarg_t) rc;
         
-        return sys_ipc_forward_common(callid, handle,
+        return sys_ipc_forward_common(chandle, phandle,
             IPC_GET_IMETHOD(newdata), IPC_GET_ARG1(newdata),
             IPC_GET_ARG2(newdata), IPC_GET_ARG3(newdata),
-            IPC_GET_ARG4(newdata), IPC_GET_ARG5(newdata), mode, true); 
+            IPC_GET_ARG4(newdata), IPC_GET_ARG5(newdata), mode, true);
 }
 
@@ -613 +621 @@
  * than the generic sys_ipc_answer().
  *
- * @param callid Hash of the call to be answered.
- * @param retval Return value of the answer.
- * @param arg1   Service-defined return value.
- * @param arg2   Service-defined return value.
- * @param arg3   Service-defined return value.
- * @param arg4   Service-defined return value.
+ * @param chandle  Call handle to be answered.
+ * @param retval   Return value of the answer.
+ * @param arg1     Service-defined return value.
+ * @param arg2     Service-defined return value.
+ * @param arg3     Service-defined return value.
+ * @param arg4     Service-defined return value.
  *
  * @return 0 on success, otherwise an error code.
  *
  */
-sysarg_t sys_ipc_answer_fast(sysarg_t callid, sysarg_t retval,
-    sysarg_t arg1, sysarg_t arg2, sysarg_t arg3, sysarg_t arg4)
-{
-        /* Do not answer notification callids */
-        if (callid & IPC_CALLID_NOTIFICATION)
-                return 0;
-        
-        call_t *call = get_call(callid);
-        if (!call)
+sysarg_t sys_ipc_answer_fast(sysarg_t chandle, sysarg_t retval, sysarg_t arg1,
+    sysarg_t arg2, sysarg_t arg3, sysarg_t arg4)
+{
+        kobject_t *kobj = cap_unpublish(TASK, chandle, KOBJECT_TYPE_CALL);
+        if (!kobj)
                 return ENOENT;
         
+        call_t *call = kobj->call;
+
         ipc_data_t saved_data;
         bool saved;
@@ -657 +663 @@
         
         ipc_answer(&TASK->answerbox, call);
+
+        kobject_put(kobj);
+        cap_free(TASK, chandle);
+
         return rc;
 }
@@ -662 +672 @@
 /** Answer an IPC call.
  *
- * @param callid Hash of the call to be answered.
- * @param data   Userspace address of call data with the answer.
+ * @param chandle Call handle to be answered.
+ * @param data    Userspace address of call data with the answer.
  *
  * @return 0 on success, otherwise an error code.
  *
  */
-sysarg_t sys_ipc_answer_slow(sysarg_t callid, ipc_data_t *data)
-{
-        /* Do not answer notification callids */
-        if (callid & IPC_CALLID_NOTIFICATION)
-                return 0;
-        
-        call_t *call = get_call(callid);
-        if (!call)
+sysarg_t sys_ipc_answer_slow(sysarg_t chandle, ipc_data_t *data)
+{
+        kobject_t *kobj = cap_unpublish(TASK, chandle, KOBJECT_TYPE_CALL);
+        if (!kobj)
                 return ENOENT;
         
+        call_t *call = kobj->call;
+
         ipc_data_t saved_data;
         bool saved;
@@ -689 +697 @@
         int rc = copy_from_uspace(&call->data.args, &data->args, 
             sizeof(call->data.args));
-        if (rc != 0)
+        if (rc != 0) {
+                /*
+                 * Republish the capability so that the call does not get lost.
+                 */
+                cap_publish(TASK, chandle, kobj);
                 return rc;
+        }
         
         rc = answer_preprocess(call, saved ? &saved_data : NULL);
         
         ipc_answer(&TASK->answerbox, call);
+
+        kobject_put(kobj);
+        cap_free(TASK, chandle);
+
         return rc;
 }
@@ -727 +744 @@
  *                 for explanation.
  *
- * @return Hash of the call.
+ * @return Capability handle of the received request.
+ * @return CAP_NIL for answers, notifications and when there is no call.
+ * @return Negative error code on error.
  */
 sysarg_t sys_ipc_wait_for_call(ipc_data_t *calldata, uint32_t usec,
@@ -746 +765 @@
         udebug_stoppable_end();
 #endif
-        
-        if (!call)
-                return 0;
+
+        if (!call) {
+                STRUCT_TO_USPACE(calldata, &(ipc_data_t){});
+                return CAP_NIL;
+        }
         
         if (call->flags & IPC_CALL_NOTIF) {
@@ -759 +780 @@
                 kobject_put(call->kobject);
                 
-                return (sysarg_t) call;
+                return CAP_NIL;
         }
         
@@ -775 +796 @@
                 kobject_put(call->kobject);
                 
-                return (sysarg_t) call;
+                return CAP_NIL;
         }
         
@@ -781 +802 @@
                 goto restart;
         
-        /* Include phone address('id') of the caller in the request,
-         * copy whole call->data, not only call->data.args */
-        if (STRUCT_TO_USPACE(calldata, &call->data)) {
-                /*
-                 * The callee will not receive this call and no one else has
-                 * a chance to answer it. Reply with the EPARTY error code.
-                 */
-                ipc_data_t saved_data;
-                bool saved;
-                
-                if (answer_need_old(call)) {
-                        memcpy(&saved_data, &call->data, sizeof(call->data));
-                        saved = true;
-                } else
-                        saved = false;
-                
-                IPC_SET_RETVAL(call->data, EPARTY);
-                (void) answer_preprocess(call, saved ? &saved_data : NULL);
-                ipc_answer(&TASK->answerbox, call);
-                return 0;
-        }
-        
-        return (sysarg_t) call;
+        int rc;
+        cap_handle_t handle = cap_alloc(TASK);
+        if (handle < 0) {
+                rc = handle;
+                goto error;
+        }
+        
+        /*
+         * Include phone hash of the caller in the request, copy the whole
+         * call->data, not only call->data.args.
+         */
+        rc = STRUCT_TO_USPACE(calldata, &call->data);
+        if (rc != EOK)
+                goto error;
+
+        kobject_add_ref(call->kobject);
+        cap_publish(TASK, handle, call->kobject);
+        return handle;
+
+error:
+        if (handle >= 0)
+                cap_free(TASK, handle);
+
+        /*
+         * The callee will not receive this call and no one else has a chance to
+         * answer it. Reply with the EPARTY error code.
+         */
+        ipc_data_t saved_data;
+        bool saved;
+
+        if (answer_need_old(call)) {
+                memcpy(&saved_data, &call->data, sizeof(call->data));
+                saved = true;
+        } else
+                saved = false;
+
+        IPC_SET_RETVAL(call->data, EPARTY);
+        (void) answer_preprocess(call, saved ? &saved_data : NULL);
+        ipc_answer(&TASK->answerbox, call);
+
+        return rc;
 }