xnu-7195.101.1.tar.gz

[apple/xnu.git] / osfmk / kern / coalition.c

diff --git a/osfmk/kern/coalition.c b/osfmk/kern/coalition.c
index e77ca4e68fb07a21094e9246519fe01d82cc32ee..af789e0b2f7fba8739d5d664d00b435a55cce6fc 100644 (file)
--- a/osfmk/kern/coalition.c
+++ b/osfmk/kern/coalition.c
@@ -89,7 +89,7 @@ int merge_adaptive_coalitions;
 LCK_GRP_DECLARE(coalitions_lck_grp, "coalition");
 
 /* coalitions_list_lock protects coalition_count, coalitions queue, next_coalition_id. */
-static LCK_MTX_DECLARE(coalitions_list_lock, &coalitions_lck_grp);
+static LCK_RW_DECLARE(coalitions_list_lock, &coalitions_lck_grp);
 static uint64_t coalition_count;
 static uint64_t coalition_next_id = 1;
 static queue_head_t coalitions_q;
@@ -1198,7 +1198,7 @@ coalition_create_internal(int type, int role, boolean_t privileged, coalition_t
 
        lck_mtx_init(&new_coal->lock, &coalitions_lck_grp, LCK_ATTR_NULL);
 
-       lck_mtx_lock(&coalitions_list_lock);
+       lck_rw_lock_exclusive(&coalitions_list_lock);
        new_coal->id = coalition_next_id++;
        coalition_count++;
        enqueue_tail(&coalitions_q, &new_coal->coalitions);
@@ -1215,7 +1215,7 @@ coalition_create_internal(int type, int role, boolean_t privileged, coalition_t
 #endif
        cid = new_coal->id;
        ctype = new_coal->type;
-       lck_mtx_unlock(&coalitions_list_lock);
+       lck_rw_unlock_exclusive(&coalitions_list_lock);
 
        coal_dbg("id:%llu, type:%s", cid, coal_type_str(ctype));
 
@@ -1281,22 +1281,29 @@ coalition_release(coalition_t coal)
  * coalition_find_by_id_internal
  * Returns: Coalition object with specified id, NOT referenced.
  *          If not found, returns COALITION_NULL.
- * Condition: coalitions_list_lock must be LOCKED.
+ *          If found, returns a locked coalition.
+ *
+ * Condition: No locks held
  */
 static coalition_t
 coalition_find_by_id_internal(uint64_t coal_id)
 {
+       coalition_t coal;
+
        if (coal_id == 0) {
                return COALITION_NULL;
        }
 
-       lck_mtx_assert(&coalitions_list_lock, LCK_MTX_ASSERT_OWNED);
-       coalition_t coal;
+       lck_rw_lock_shared(&coalitions_list_lock);
        qe_foreach_element(coal, &coalitions_q, coalitions) {
                if (coal->id == coal_id) {
+                       coalition_lock(coal);
+                       lck_rw_unlock_shared(&coalitions_list_lock);
                        return coal;
                }
        }
+       lck_rw_unlock_shared(&coalitions_list_lock);
+
        return COALITION_NULL;
 }
 
@@ -1308,23 +1315,16 @@ coalition_find_by_id_internal(uint64_t coal_id)
 coalition_t
 coalition_find_by_id(uint64_t cid)
 {
-       if (cid == 0) {
-               return COALITION_NULL;
-       }
-
-       lck_mtx_lock(&coalitions_list_lock);
-
        coalition_t coal = coalition_find_by_id_internal(cid);
+
        if (coal == COALITION_NULL) {
-               lck_mtx_unlock(&coalitions_list_lock);
                return COALITION_NULL;
        }
 
-       coalition_lock(coal);
+       /* coal is locked */
 
        if (coal->reaped) {
                coalition_unlock(coal);
-               lck_mtx_unlock(&coalitions_list_lock);
                return COALITION_NULL;
        }
 
@@ -1338,7 +1338,6 @@ coalition_find_by_id(uint64_t cid)
 #endif
 
        coalition_unlock(coal);
-       lck_mtx_unlock(&coalitions_list_lock);
 
        coal_dbg("id:%llu type:%s ref_count:%u",
            coal->id, coal_type_str(coal->type), rc);
@@ -1357,25 +1356,18 @@ coalition_find_by_id(uint64_t cid)
 coalition_t
 coalition_find_and_activate_by_id(uint64_t cid)
 {
-       if (cid == 0) {
-               return COALITION_NULL;
-       }
-
-       lck_mtx_lock(&coalitions_list_lock);
-
        coalition_t coal = coalition_find_by_id_internal(cid);
+
        if (coal == COALITION_NULL) {
-               lck_mtx_unlock(&coalitions_list_lock);
                return COALITION_NULL;
        }
 
-       coalition_lock(coal);
+       /* coal is locked */
 
        if (coal->reaped || coal->terminated) {
                /* Too late to put something new into this coalition, it's
                 * already on its way out the door */
                coalition_unlock(coal);
-               lck_mtx_unlock(&coalitions_list_lock);
                return COALITION_NULL;
        }
 
@@ -1393,7 +1385,6 @@ coalition_find_and_activate_by_id(uint64_t cid)
 #endif
 
        coalition_unlock(coal);
-       lck_mtx_unlock(&coalitions_list_lock);
 
        coal_dbg("id:%llu type:%s ref_count:%u, active_count:%u",
            coal->id, coal_type_str(coal->type), rc, ac);
@@ -2003,10 +1994,10 @@ coalition_reap_internal(coalition_t coal)
 
        coalition_unlock(coal);
 
-       lck_mtx_lock(&coalitions_list_lock);
+       lck_rw_lock_exclusive(&coalitions_list_lock);
        coalition_count--;
        remqueue(&coal->coalitions);
-       lck_mtx_unlock(&coalitions_list_lock);
+       lck_rw_unlock_exclusive(&coalitions_list_lock);
 
        /* Release the list's reference and launchd's reference. */
        coalition_release(coal);
@@ -2116,7 +2107,7 @@ coalitions_get_list(int type, struct procinfo_coalinfo *coal_list, int list_sz)
        int ncoals = 0;
        struct coalition *coal;
 
-       lck_mtx_lock(&coalitions_list_lock);
+       lck_rw_lock_shared(&coalitions_list_lock);
        qe_foreach_element(coal, &coalitions_q, coalitions) {
                if (!coal->reaped && (type < 0 || type == (int)coal->type)) {
                        if (coal_list && ncoals < list_sz) {
@@ -2125,7 +2116,7 @@ coalitions_get_list(int type, struct procinfo_coalinfo *coal_list, int list_sz)
                        ++ncoals;
                }
        }
-       lck_mtx_unlock(&coalitions_list_lock);
+       lck_rw_unlock_shared(&coalitions_list_lock);
 
        return ncoals;
 }