Messages in this thread Patch in this message | | | From | Jason Wessel <> | Subject | [PATCH 3/7] kms,kdb: Force unblank a console device | Date | Fri, 12 Feb 2010 16:36:24 -0600 |
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The kgdboc pre exception handler must atomically save the state of the existing VC console and activate it, if it is blanked.
Before restoring the kernel to a running state, the kgdboc post exception handler will restore the state of the VC variables that got changed while atomic.
CC: David Airlie <airlied@linux.ie> CC: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> --- drivers/serial/kgdboc.c | 25 ++++++++++++---- drivers/video/console/fbcon.c | 7 ++++ include/linux/kgdb.h | 8 +++++ kernel/debug/Makefile | 1 + kernel/debug/kms_hooks.c | 62 +++++++++++++++++++++++++++++++++++++++++ 5 files changed, 96 insertions(+), 7 deletions(-) create mode 100644 kernel/debug/kms_hooks.c
diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c index bc1fec1..246b7c3 100644 --- a/drivers/serial/kgdboc.c +++ b/drivers/serial/kgdboc.c @@ -220,13 +220,19 @@ static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp) return configure_kgdboc(); } +static int dbg_restore_graphics; + static void kgdboc_pre_exp_handler(void) { - if (kgdboc_use_kms && dbg_kms_ops && - dbg_kms_ops->activate_console) - if (dbg_kms_ops->activate_console(dbg_kms_ops)) + if (!dbg_restore_graphics && kgdboc_use_kms && dbg_kms_ops && + dbg_kms_ops->activate_console) { + if (dbg_kms_ops->activate_console(dbg_kms_ops)) { printk(KERN_ERR "kgdboc: kernel mode switch error\n"); - + } else { + dbg_restore_graphics = 1; + dbg_pre_vt_hook(); + } + } /* Increment the module count when the debugger is active */ if (!kgdb_connected) try_module_get(THIS_MODULE); @@ -238,9 +244,14 @@ static void kgdboc_post_exp_handler(void) if (!kgdb_connected) module_put(THIS_MODULE); if (kgdboc_use_kms && dbg_kms_ops && - dbg_kms_ops->restore_console) - if (dbg_kms_ops->restore_console(dbg_kms_ops)) - printk(KERN_ERR "kgdboc: graphics restore failed\n"); + dbg_kms_ops->restore_console) { + if (dbg_restore_graphics) { + if (dbg_kms_ops->restore_console(dbg_kms_ops)) + printk(KERN_ERR "kgdboc: graphics restore failed\n"); + dbg_restore_graphics = 0; + dbg_post_vt_hook(); + } + } kgdboc_clear_kbd(); } diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c index 3681c6a..6f2ed5a 100644 --- a/drivers/video/console/fbcon.c +++ b/drivers/video/console/fbcon.c @@ -75,6 +75,7 @@ #include <linux/init.h> #include <linux/interrupt.h> #include <linux/crc32.h> /* For counting font checksums */ +#include <linux/kgdb.h> #include <asm/fb.h> #include <asm/irq.h> #include <asm/system.h> @@ -2318,6 +2319,12 @@ static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch) } } + if (in_dbg_master()) { + if (info->fbops->fb_blank) + info->fbops->fb_blank(blank, info); + return 0; + } + if (!fbcon_is_inactive(vc, info)) { if (ops->blank_state != blank) { ops->blank_state = blank; diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 9cd6baa..81bb298 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -286,6 +286,14 @@ extern atomic_t kgdb_active; #endif /* CONFIG_KGDB */ /* Common to all that include kgdb.h */ +#ifdef CONFIG_VT +extern void dbg_pre_vt_hook(void); +extern void dbg_post_vt_hook(void); +#else /* ! CONFIG_VT */ +#define dbg_pre_vt_hook() +#define dbg_post_vt_hook() +#endif /* CONFIG_VT */ + struct dbg_kms_ops { int (*activate_console) (struct dbg_kms_ops *ops); int (*restore_console) (struct dbg_kms_ops *ops); diff --git a/kernel/debug/Makefile b/kernel/debug/Makefile index c72de00..fe342c0 100644 --- a/kernel/debug/Makefile +++ b/kernel/debug/Makefile @@ -3,5 +3,6 @@ # obj-$(CONFIG_KGDB) += debug_core.o gdbstub.o +obj-$(CONFIG_VT) += kms_hooks.o obj-$(CONFIG_KGDB_KDB) += kdb/ diff --git a/kernel/debug/kms_hooks.c b/kernel/debug/kms_hooks.c new file mode 100644 index 0000000..c56b7ce --- /dev/null +++ b/kernel/debug/kms_hooks.c @@ -0,0 +1,62 @@ +/* + * Created by: Jason Wessel <jason.wessel@windriver.com> + * + * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#ifdef CONFIG_VT +#include <linux/kgdb.h> +#include <linux/console.h> +#include <linux/vt_kern.h> +#include <linux/selection.h> +#include <linux/kdb.h> +#include "kdb/kdb_private.h" + +static int dbg_orig_vc_mode; +static int saved_fg_con; +static int saved_last_con; +static int saved_want_con; + +void dbg_pre_vt_hook(void) +{ + struct vc_data *vc = vc_cons[fg_console].d; + saved_fg_con = fg_console; + saved_last_con = last_console; + saved_want_con = want_console; + dbg_orig_vc_mode = vc->vc_mode; + vc->vc_mode = KD_TEXT; + console_blanked = 0; + vc->vc_sw->con_blank(vc, 0, 1); + vc->vc_sw->con_set_palette(vc, color_table); +#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 */ +} +EXPORT_SYMBOL_GPL(dbg_pre_vt_hook); + +void dbg_post_vt_hook(void) +{ + fg_console = saved_fg_con; + last_console = saved_last_con; + want_console = saved_want_con; + vc_cons[fg_console].d->vc_mode = dbg_orig_vc_mode; +} +EXPORT_SYMBOL_GPL(dbg_post_vt_hook); +#endif /* CONFIG_VT */ -- 1.6.4.rc1
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