diff options
| -rw-r--r-- | drivers/char/vt.c | 61 | ||||
| -rw-r--r-- | include/linux/console.h | 13 |
2 files changed, 74 insertions, 0 deletions
diff --git a/drivers/char/vt.c b/drivers/char/vt.c index 7cdb6ee569cd..117ce99115dc 100644 --- a/drivers/char/vt.c +++ b/drivers/char/vt.c @@ -187,10 +187,15 @@ static DECLARE_WORK(console_work, console_callback); * fg_console is the current virtual console, * last_console is the last used one, * want_console is the console we want to switch to, + * saved_* variants are for save/restore around kernel debugger enter/leave */ int fg_console; int last_console; int want_console = -1; +int saved_fg_console; +int saved_last_console; +int saved_want_console; +int saved_vc_mode; /* * For each existing display, we have a pointer to console currently visible @@ -3414,6 +3419,62 @@ int con_is_bound(const struct consw *csw) EXPORT_SYMBOL(con_is_bound); /** + * con_debug_enter - prepare the console for the kernel debugger + * @sw: console driver + * + * Called when the console is taken over by the kernel debugger, this + * function needs to save the current console state, then put the console + * into a state suitable for the kernel debugger. + * + * RETURNS: + * Zero on success, nonzero if a failure occurred when trying to prepare + * the console for the debugger. + */ +int con_debug_enter(struct vc_data *vc) +{ + int ret = 0; + + saved_fg_console = fg_console; + saved_last_console = last_console; + saved_want_console = want_console; + saved_vc_mode = vc->vc_mode; + vc->vc_mode = KD_TEXT; + console_blanked = 0; + if (vc->vc_sw->con_debug_enter) + ret = vc->vc_sw->con_debug_enter(vc); + return ret; +} +EXPORT_SYMBOL_GPL(con_debug_enter); + +/** + * con_debug_leave - restore console state + * @sw: console driver + * + * Restore the console state to what it was before the kernel debugger + * was invoked. + * + * RETURNS: + * Zero on success, nonzero if a failure occurred when trying to restore + * the console. + */ +int con_debug_leave(void) +{ + struct vc_data *vc; + int ret = 0; + + fg_console = saved_fg_console; + last_console = saved_last_console; + want_console = saved_want_console; + vc_cons[fg_console].d->vc_mode = saved_vc_mode; + + vc = vc_cons[fg_console].d; + if (vc->vc_sw->con_debug_leave) + ret = vc->vc_sw->con_debug_leave(vc); + return ret; +} +EXPORT_SYMBOL_GPL(con_debug_leave); + +/** * register_con_driver - register console driver to console layer * @csw: console driver * @first: the first console to take over, minimum value is 0 diff --git a/include/linux/console.h b/include/linux/console.h index dcca5339ceb3..f76fc297322d 100644 --- a/include/linux/console.h +++ b/include/linux/console.h @@ -55,6 +55,16 @@ struct consw { void (*con_invert_region)(struct vc_data *, u16 *, int); u16 *(*con_screen_pos)(struct vc_data *, int); unsigned long (*con_getxy)(struct vc_data *, unsigned long, int *, int *); + /* + * Prepare the console for the debugger. This includes, but is not + * limited to, unblanking the console, loading an appropriate + * palette, and allowing debugger generated output. + */ + int (*con_debug_enter)(struct vc_data *); + /* + * Restore the console to its pre-debug state as closely as possible. + */ + int (*con_debug_leave)(struct vc_data *); }; extern const struct consw *conswitchp; @@ -69,6 +79,9 @@ int register_con_driver(const struct consw *csw, int first, int last); int unregister_con_driver(const struct consw *csw); int take_over_console(const struct consw *sw, int first, int last, int deflt); void give_up_console(const struct consw *sw); +int con_debug_enter(struct vc_data *vc); +int con_debug_leave(void); + /* scroll */ #define SM_UP (1) #define SM_DOWN (2) |