Add a /S mode to DDB "ex" command, which interprets and prints the

value at the requested address as a symbol.  For example, "ex /S
aio_swake" prints the name of the function currently registered in
via aio_swake hook.

The change as committed differs slightly from the patch in the PR,
as I force the size of the retrieved value (and the automatic
address increment) to be sizeof(void *).  This seems to provide
the most useful auto-increment behavior, and defaults using the
default size (4), which is not sizeof(void *) on 64-bit platforms.

MFC after:	3 days
PR:		57976
Submitted by:	Dan Strick <strick at covad.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/sys/ddb/db_examine.c b/sys/ddb/db_examine.c
index eba6151..fc4f472 100644
--- a/sys/ddb/db_examine.c
+++ b/sys/ddb/db_examine.c
@@ -166,6 +166,12 @@ db_examine(addr, fmt, count)
 					db_printf("\\%03o", (int)value);
 				}
 				break;
+			    case 'S':	/* symbol */
+				value = db_get_value(addr, sizeof(void *),
+				    FALSE);
+				addr += sizeof(void *);
+				db_printsym(value, DB_STGY_ANY);
+				break;
 			    case 'i':	/* instruction */
 				addr = db_disasm(addr, FALSE);
 				break;