ipc_entry_lookup: Generalize warnings about bogus port names

Looking up a bogus port name is generally a sign of a real bug, such as a
spurious mach port deallocation.

4 files changed, 54 insertions, 4 deletions

diff --git a/ipc/ipc_kmsg.c b/ipc/ipc_kmsg.c
index fb8de249..096769f2 100644
--- a/ipc/ipc_kmsg.c
+++ b/ipc/ipc_kmsg.c
@@ -686,7 +686,10 @@ ipc_kmsg_copyin_header(
 
 		entry = ipc_entry_lookup (space, dest_name);
 		if (entry == IE_NULL)
+		{
+			ipc_entry_lookup_failed (dest_name);
 			goto abort_async;
+		}
 		bits = entry->ie_bits;
 
 		/* check type bits */
@@ -738,7 +741,10 @@ ipc_kmsg_copyin_header(
 
 		entry = ipc_entry_lookup (space, dest_name);
 		if (entry == IE_NULL)
+		{
+			ipc_entry_lookup_failed (dest_name);
 			goto abort_request;
+		}
 		bits = entry->ie_bits;
 
 		/* check type bits */
@@ -752,7 +758,10 @@ ipc_kmsg_copyin_header(
 
 		entry = ipc_entry_lookup (space, reply_name);
 		if (entry == IE_NULL)
+		{
+			ipc_entry_lookup_failed (reply_name);
 			goto abort_request;
+		}
 		bits = entry->ie_bits;
 
 		/* check type bits */
@@ -819,7 +828,10 @@ ipc_kmsg_copyin_header(
 
 		entry = ipc_entry_lookup (space, dest_name);
 		if (entry == IE_NULL)
+		{
+			ipc_entry_lookup_failed (dest_name);
 			goto abort_reply;
+		}
 		bits = entry->ie_bits;
 
 		/* check and type bits */
@@ -892,6 +904,8 @@ ipc_kmsg_copyin_header(
 
 		if (((entry = ipc_entry_lookup(space, notify)) == IE_NULL) ||
 		    ((entry->ie_bits & MACH_PORT_TYPE_RECEIVE) == 0)) {
+			if (entry == IE_NULL)
+				ipc_entry_lookup_failed (notify);
 			is_write_unlock(space);
 			return MACH_SEND_INVALID_NOTIFY;
 		}
@@ -916,8 +930,10 @@ ipc_kmsg_copyin_header(
 		 */
 
 		entry = ipc_entry_lookup(space, name);
-		if (entry == IE_NULL)
+		if (entry == IE_NULL) {
+			ipc_entry_lookup_failed (name);
 			goto invalid_dest;
+		}
 
 		assert(reply_type != 0); /* because name not null */
 
@@ -1067,8 +1083,10 @@ ipc_kmsg_copyin_header(
 		 */
 
 		entry = ipc_entry_lookup(space, dest_name);
-		if (entry == IE_NULL)
+		if (entry == IE_NULL) {
+			ipc_entry_lookup_failed (dest_name);
 			goto invalid_dest;
+		}
 
 		kr = ipc_right_copyin(space, dest_name, entry,
 				      dest_type, FALSE,
@@ -1123,12 +1141,17 @@ ipc_kmsg_copyin_header(
 		 */
 
 		dest_entry = ipc_entry_lookup(space, dest_name);
-		if (dest_entry == IE_NULL)
+		if (dest_entry == IE_NULL) {
+			ipc_entry_lookup_failed (dest_name);
 			goto invalid_dest;
+		}
 
 		reply_entry = ipc_entry_lookup(space, reply_name);
 		if (reply_entry == IE_NULL)
+		{
+			ipc_entry_lookup_failed (reply_name);
 			goto invalid_reply;
+		}
 
 		assert(dest_entry != reply_entry); /* names are not equal */
 		assert(reply_type != 0); /* because reply_name not null */
@@ -2093,6 +2116,8 @@ ipc_kmsg_copyout_header(
 			if (((entry = ipc_entry_lookup(space, notify))
 								== IE_NULL) ||
 			    ((entry->ie_bits & MACH_PORT_TYPE_RECEIVE) == 0)) {
+				if (entry == IE_NULL)
+					ipc_entry_lookup_failed (notify);
 				is_read_unlock(space);
 				return MACH_RCV_INVALID_NOTIFY;
 			}
diff --git a/ipc/ipc_space.h b/ipc/ipc_space.h
index b4eb5ba6..22460877 100644
--- a/ipc/ipc_space.h
+++ b/ipc/ipc_space.h
@@ -47,6 +47,7 @@
 #include <kern/lock.h>
 #include <kern/rdxtree.h>
 #include <kern/slab.h>
+#include <kern/printf.h>
 #include <ipc/ipc_entry.h>
 #include <ipc/ipc_types.h>
 
@@ -155,6 +156,18 @@ ipc_entry_lookup(
 	return entry;
 }
 
+extern volatile boolean_t mach_port_deallocate_debug;
+
+static inline void
+ipc_entry_lookup_failed(mach_port_name_t name)
+{
+	if (name == MACH_PORT_NULL || name == MACH_PORT_DEAD)
+		return;
+	printf("task %.*s looked up a bogus port %lu, most probably a bug.\n", (int) sizeof current_task()->name, current_task()->name, (unsigned long) name);
+	if (mach_port_deallocate_debug)
+		SoftDebugger("ipc_entry_lookup");
+}
+
 /*
  *	Routine:	ipc_entry_get
  *	Purpose:
diff --git a/ipc/mach_msg.c b/ipc/mach_msg.c
index 118ce4b3..abeeb643 100644
--- a/ipc/mach_msg.c
+++ b/ipc/mach_msg.c
@@ -495,7 +495,10 @@ mach_msg_trap(
 			ipc_entry_t entry;
 			entry = ipc_entry_lookup (space, reply_name);
 			if (entry == IE_NULL)
+			{
+				ipc_entry_lookup_failed (reply_name);
 				goto abort_request_copyin;
+			}
 			reply_port = (ipc_port_t) entry->ie_object;
 			assert(reply_port != IP_NULL);
 		    }
@@ -508,7 +511,10 @@ mach_msg_trap(
 			ipc_entry_bits_t bits;
 			entry = ipc_entry_lookup (space, dest_name);
 			if (entry == IE_NULL)
+			{
+				ipc_entry_lookup_failed (dest_name);
 				goto abort_request_copyin;
+			}
 			bits = entry->ie_bits;
 
 			/* check type bits */
@@ -620,7 +626,10 @@ mach_msg_trap(
 
 			entry = ipc_entry_lookup (space, dest_name);
 			if (entry == IE_NULL)
+			{
+				ipc_entry_lookup_failed (dest_name);
 				goto abort_reply_dest_copyin;
+			}
 
 			/* check type bits */
 			if (IE_BITS_TYPE (entry->ie_bits) !=
@@ -668,7 +677,10 @@ mach_msg_trap(
 			ipc_entry_bits_t bits;
 			entry = ipc_entry_lookup (space, rcv_name);
 			if (entry == IE_NULL)
+			{
+				ipc_entry_lookup_failed (rcv_name);
 				goto abort_reply_rcv_copyin;
+			}
 			bits = entry->ie_bits;
 
 			/* check type bits; looking for receive or set */
diff --git a/ipc/mach_port.c b/ipc/mach_port.c
index a07b4fe9..d8696e23 100644
--- a/ipc/mach_port.c
+++ b/ipc/mach_port.c
@@ -534,7 +534,7 @@ mach_port_allocate(
  *		KERN_INVALID_NAME	The name doesn't denote a right.
  */
 
-static volatile boolean_t mach_port_deallocate_debug = FALSE;
+volatile boolean_t mach_port_deallocate_debug = FALSE;
 
 kern_return_t
 mach_port_destroy(