xnu-4903.231.4.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 aabb15adac8196902149f60dbfa16a0ecb4943c4..facaf2af0d0bf61f3f74ca090f9372a556fe2a22 100644 (file)
--- a/osfmk/ipc/ipc_entry.c
+++ b/osfmk/ipc/ipc_entry.c
@@ -79,6 +79,7 @@
 #include <ipc/ipc_table.h>
 #include <ipc/ipc_port.h>
 #include <string.h>
+#include <sys/kdebug.h>
 
 /*
  *     Routine:        ipc_entry_lookup
@@ -103,8 +104,9 @@ 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 +191,14 @@ 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 +308,9 @@ 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 +440,7 @@ 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++;
@@ -481,6 +490,14 @@ ipc_entry_modified(
                space->is_low_mod = index;
        if (index > space->is_high_mod)
                space->is_high_mod = index;
+
+       KERNEL_DEBUG_CONSTANT(
+               MACHDBG_CODE(DBG_MACH_IPC,MACH_IPC_PORT_ENTRY_MODIFY) | DBG_FUNC_NONE,
+               space->is_task ? task_pid(space->is_task) : 0,
+               name,
+               entry->ie_bits,
+               0,
+               0);
 }
 
 #define IPC_ENTRY_GROW_STATS 1
@@ -608,14 +625,7 @@ 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));
@@ -749,3 +759,29 @@ ipc_entry_grow_table(
 
        return KERN_SUCCESS;
 }
+
+
+/*
+ *     Routine:        ipc_entry_name_mask
+ *     Purpose:
+ *             Ensure a mach port name has the default ipc entry
+ *             generation bits set. This can be used to ensure that
+ *             a name passed in by user space matches names generated
+ *             by the kernel.
+ *     Conditions:
+ *             None.
+ *     Returns:
+ *             'name' input with default generation bits masked or added
+ *             as appropriate.
+ */
+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_GEN_MASK + IE_BITS_GEN_ONE);
+       return name | null_name;
+#else
+       static mach_port_name_t null_name = MACH_PORT_MAKE(0, ~(IE_BITS_GEN_MASK + IE_BITS_GEN_ONE));
+       return name & ~null_name;
+#endif
+}