Add a simple scripting facility to DDB(4), allowing the user to

define a set of named scripts.  Each script consists of a list of DDB
commands separated by ";"s that will be executed verbatim.  No higher
level language constructs, such as branching, are provided for:
scripts are executed by sequentially injecting commands into the DDB
input buffer.

Four new commands are present in DDB: "run" to run a specific script,
"script" to define or print a script, "scripts" to list currently
defined scripts, and "unscript" to delete a script, modeled on shell
alias commands.  Scripts may also be manipulated using sysctls in the
debug.ddb.scripting MIB space, although users will prefer to use the
soon-to-be-added ddb(8) tool for usability reasons.

Scripts with certain names are automatically executed on various DDB
events, such as entering the debugger via a panic, a witness error,
watchdog, breakpoint, sysctl, serial break, etc, allowing customized
handling.

MFC after:	3 months

1 files changed, 3 insertions, 0 deletions

diff --git a/sys/ddb/db_main.c b/sys/ddb/db_main.c
index 0a9fbf7..e63b4fc0 100644
--- a/sys/ddb/db_main.c
+++ b/sys/ddb/db_main.c
@@ -194,6 +194,7 @@ db_trap(int type, int code)
 	jmp_buf jb;
 	void *prev_jb;
 	boolean_t bkpt, watchpt;
+	const char *why;
 
 	/*
 	 * Don't handle the trap if the console is unavailable (i.e. it
@@ -222,6 +223,8 @@ db_trap(int type, int code)
 				db_printf("Stopped at\t");
 			db_print_loc_and_inst(db_dot);
 		}
+		why = kdb_why;
+		db_script_kdbenter(why != KDB_WHY_UNSET ? why : "unknown");
 		db_command_loop();
 		(void)kdb_jmpbuf(prev_jb);
 	}