Changeset 9e87562 in mainline for kernel/generic/src/ipc/irq.c

Timestamp:

2017-09-18T20:52:12Z (8 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

6abfd250

Parents:

e5f5ce0

Message:

Make all accesses to capabilites exclusive

This commit makes sure that all accesses to the capabilities array and other
metadata are protected by a mutex. This is necessary for future resizing of the
capabilities array.

Group task's capabilities by type so that it is possible to visit all
capabilities of the given type effectively.

Provide cap_publish() and cap_unpublish() to automate steps that make the
capability visible/invisible to userspace and insert/remove the capability from
the respective type list.

File:

• kernel/generic/src/ipc/irq.c (modified) (3 diffs)

kernel/generic/src/ipc/irq.c

@@ -314 +314 @@
         }
         
-        cap_t *cap = cap_get_current(handle, CAP_TYPE_ALLOCATED);
-        assert(cap);
-        
         irq_initialize(irq);
         irq->inr = inr;
@@ -327 +324 @@
         irq->notif_cfg.counter = 0;
         
-        cap->kobject = (void *) irq;
-        
         /*
-         * Insert the IRQ structure into the uspace IRQ hash table and retype
-         * the capability. By retyping the capability inside the critical
-         * section, we make sure another thread cannot attempt to unregister the
-         * IRQ before it is inserted into the hash table.
+         * Insert the IRQ structure into the uspace IRQ hash table.
          */
         irq_spinlock_lock(&irq_uspace_hash_table_lock, true);
         irq_spinlock_lock(&irq->lock, false);
         
-        cap->type = CAP_TYPE_IRQ;
         hash_table_insert(&irq_uspace_hash_table, key, &irq->link);
         
         irq_spinlock_unlock(&irq->lock, false);
         irq_spinlock_unlock(&irq_uspace_hash_table_lock, true);
+
+        cap_publish(TASK, handle, CAP_TYPE_IRQ, irq);
         
         return handle;
@@ -357 +350 @@
 int ipc_irq_unsubscribe(answerbox_t *box, int handle)
 {
-        irq_spinlock_lock(&TASK->lock, true);
-        cap_t *cap = cap_get_current(handle, CAP_TYPE_IRQ);
-        if (!cap) {
-                irq_spinlock_unlock(&TASK->lock, true);
+        cap_t *cap = cap_unpublish(TASK, handle, CAP_TYPE_IRQ);
+        if (!cap)
                 return ENOENT;
-        }
-        /* Make sure only one thread can win the race to unsubscribe. */
-        cap->type = CAP_TYPE_ALLOCATED;
-        irq_spinlock_unlock(&TASK->lock, true);
         
         irq_t *irq = (irq_t *) cap->kobject;