Changeset d891cba in mainline

Timestamp:

2012-08-17T11:03:10Z (12 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

ffc1b1d

Parents:

f9bd2e3

Message:

Phones in IPC cleanup need to be accessed under the protection of their
mutex as the other side may be tampering with them.

File:

• kernel/generic/src/ipc/ipc.c (modified) (4 diffs)

kernel/generic/src/ipc/ipc.c

@@ -626 +626 @@
 restart:
         /*
-         * Go through all phones, until they are all FREE. Locking is not
-         * needed, no one else should modify it when we are in cleanup
+         * Go through all phones, until they are all free.
+         * Locking is needed as there may be connection handshakes in progress.
          */
         for (i = 0; i < IPC_MAX_PHONES; i++) {
-                if (TASK->phones[i].state == IPC_PHONE_HUNGUP &&
-                    atomic_get(&TASK->phones[i].active_calls) == 0) {
-                        TASK->phones[i].state = IPC_PHONE_FREE;
-                        TASK->phones[i].callee = NULL;
+                phone_t *phone = &TASK->phones[i];
+
+                mutex_lock(&phone->lock);       
+                if ((phone->state == IPC_PHONE_HUNGUP) &&
+                    (atomic_get(&phone->active_calls) == 0)) {
+                        phone->state = IPC_PHONE_FREE;
+                        phone->callee = NULL;
                 }
 
@@ -645 +648 @@
                  * phone.
                  */
-                if ((TASK->phones[i].state == IPC_PHONE_CONNECTED) ||
-                    (TASK->phones[i].state == IPC_PHONE_SLAMMED)) {
-                        ipc_phone_hangup(&TASK->phones[i]);
+                if ((phone->state == IPC_PHONE_CONNECTED) ||
+                    (phone->state == IPC_PHONE_SLAMMED)) {
+                        mutex_unlock(&phone->lock);
+                        ipc_phone_hangup(phone);
                         /*
                          * Now there may be one extra active call, which needs
@@ -660 +664 @@
                  * IPC is now in HUNGUP state, we wait for the reply to come
                  */
-                if (TASK->phones[i].state != IPC_PHONE_FREE)
+                if (phone->state != IPC_PHONE_FREE) {
+                        mutex_unlock(&phone->lock);
                         break;
+                }
+
+                mutex_unlock(&phone->lock);
         }
                 
@@ -671 +679 @@
             SYNCH_FLAGS_NONE);
         ASSERT(call->flags & (IPC_CALL_ANSWERED | IPC_CALL_NOTIF));
-                
         ipc_call_free(call);
         goto restart;