diff options
Diffstat (limited to 'drivers/char/vt.c')
| -rw-r--r-- | drivers/char/vt.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/char/vt.c b/drivers/char/vt.c index 7cdb6ee569c..4a9eb3044e5 100644 --- a/drivers/char/vt.c +++ b/drivers/char/vt.c @@ -104,6 +104,7 @@ #include <linux/io.h> #include <asm/system.h> #include <linux/uaccess.h> +#include <linux/kdb.h> #define MAX_NR_CON_DRIVER 16 @@ -187,10 +188,15 @@ 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 +3420,78 @@ 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); +#ifdef CONFIG_KGDB_KDB + /* Set the initial LINES variable if it is not already set */ + if (vc->vc_rows < 999) { + int linecount; + char lns[4]; + const char *setargs[3] = { + "set", + "LINES", + lns, + }; + if (kdbgetintenv(setargs[0], &linecount)) { + snprintf(lns, 4, "%i", vc->vc_rows); + kdb_set(2, setargs); + } + } +#endif /* CONFIG_KGDB_KDB */ + 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 |