xnu-4570.41.2.tar.gz

[apple/xnu.git] / osfmk / ipc / ipc_entry.c

diff --git a/osfmk/ipc/ipc_entry.c b/osfmk/ipc/ipc_entry.c
index 9604a81b8bc93d4454560a0462080c07db8e60b3..288ea6a5801857470956296ef1c8c343f6932734 100644 (file)
--- a/osfmk/ipc/ipc_entry.c
+++ b/osfmk/ipc/ipc_entry.c
@@ -103,8 +103,9 @@ ipc_entry_lookup(
        if (index <  space->is_table_size) {
                 entry = &space->is_table[index];
                if (IE_BITS_GEN(entry->ie_bits) != MACH_PORT_GEN(name) ||
-                   IE_BITS_TYPE(entry->ie_bits) == MACH_PORT_TYPE_NONE)
+                   IE_BITS_TYPE(entry->ie_bits) == MACH_PORT_TYPE_NONE) {
                        entry = IE_NULL;                
+               }
        }
        else {
                entry = IE_NULL;
@@ -189,10 +190,14 @@ ipc_entry_claim(
        assert(table->ie_next < space->is_table_size);
 
        /*
-        *      Initialize the new entry.  We need only
-        *      increment the generation number and clear ie_request.
+        *      Initialize the new entry: increment gencount and reset
+        *      rollover point if it rolled over, and clear ie_request.
         */
-       gen = IE_BITS_NEW_GEN(entry->ie_bits);
+       gen = ipc_entry_new_gen(entry->ie_bits);
+       if (__improbable(ipc_entry_gen_rolled(entry->ie_bits, gen))) {
+               ipc_entry_bits_t roll = ipc_space_get_rollpoint(space);
+               gen = ipc_entry_new_rollpoint(roll);
+       }
        entry->ie_bits = gen;
        entry->ie_request = IE_REQ_NONE;
 
@@ -302,6 +307,9 @@ ipc_entry_alloc_name(
        mach_port_index_t index = MACH_PORT_INDEX(name);
        mach_port_gen_t gen = MACH_PORT_GEN(name);
 
+       if (index > ipc_table_max_entries())
+               return KERN_NO_SPACE;
+
        assert(MACH_PORT_VALID(name));
 
 
@@ -431,7 +439,7 @@ ipc_entry_dealloc(
 
        if ((index < size) && (entry == &table[index])) {
                assert(IE_BITS_GEN(entry->ie_bits) == MACH_PORT_GEN(name));
-               entry->ie_bits &= IE_BITS_GEN_MASK;
+               entry->ie_bits &= (IE_BITS_GEN_MASK | IE_BITS_ROLL_MASK);
                entry->ie_next = table->ie_next;
                table->ie_next = index;
                space->is_table_free++;
@@ -608,14 +616,7 @@ ipc_entry_grow_table(
                return KERN_RESOURCE_SHORTAGE;
        }
 
-       /* initialize new entries (free chain in backwards order) */
-       for (i = osize; i < size; i++) {
-               table[i].ie_object = IO_NULL;
-               table[i].ie_bits = IE_BITS_GEN_MASK;
-               table[i].ie_index = 0;
-               table[i].ie_next = i + 1;
-       }
-       table[size-1].ie_next = 0;
+       ipc_space_rand_freelist(space, table, osize, size);
 
        /* clear out old entries in new table */
        memset((void *)table, 0, osize * sizeof(*table));
@@ -768,10 +769,10 @@ mach_port_name_t
 ipc_entry_name_mask(mach_port_name_t name)
 {
 #ifndef NO_PORT_GEN
-       static mach_port_name_t null_name = MACH_PORT_MAKE(0, IE_BITS_NEW_GEN(IE_BITS_GEN_MASK));
+       static mach_port_name_t null_name = MACH_PORT_MAKE(0, IE_BITS_GEN_MASK + IE_BITS_GEN_ONE);
        return name | null_name;
 #else
-       static mach_port_name_t null_name = MACH_PORT_MAKE(0, ~(IE_BITS_NEW_GEN(IE_BITS_GEN_MASK)));
+       static mach_port_name_t null_name = MACH_PORT_MAKE(0, ~(IE_BITS_GEN_MASK + IE_BITS_GEN_ONE));
        return name & ~null_name;
 #endif
 }