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path: root/drivers/char/vt.c
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-rw-r--r--drivers/char/vt.c124
1 files changed, 108 insertions, 16 deletions
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index 7cdb6ee569c..50590c7f2c0 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -104,6 +104,8 @@
#include <linux/io.h>
#include <asm/system.h>
#include <linux/uaccess.h>
+#include <linux/kdb.h>
+#include <linux/ctype.h>
#define MAX_NR_CON_DRIVER 16
@@ -187,10 +189,16 @@ 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;
+static int saved_fg_console;
+static int saved_last_console;
+static int saved_want_console;
+static int saved_vc_mode;
+static int saved_console_blanked;
/*
* For each existing display, we have a pointer to console currently visible
@@ -280,8 +288,12 @@ static inline unsigned short *screenpos(struct vc_data *vc, int offset, int view
return p;
}
+/* Called from the keyboard irq path.. */
static inline void scrolldelta(int lines)
{
+ /* FIXME */
+ /* scrolldelta needs some kind of consistency lock, but the BKL was
+ and still is not protecting versus the scheduled back end */
scrollback_delta += lines;
schedule_console_callback();
}
@@ -698,7 +710,10 @@ void redraw_screen(struct vc_data *vc, int is_switch)
update_attr(vc);
clear_buffer_attributes(vc);
}
- if (update && vc->vc_mode != KD_GRAPHICS)
+
+ /* Forcibly update if we're panicing */
+ if ((update && vc->vc_mode != KD_GRAPHICS) ||
+ vt_force_oops_output(vc))
do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
}
set_cursor(vc);
@@ -736,6 +751,7 @@ static void visual_init(struct vc_data *vc, int num, int init)
vc->vc_hi_font_mask = 0;
vc->vc_complement_mask = 0;
vc->vc_can_do_color = 0;
+ vc->vc_panic_force_write = false;
vc->vc_sw->con_init(vc, init);
if (!vc->vc_complement_mask)
vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
@@ -768,6 +784,7 @@ int vc_allocate(unsigned int currcons) /* return 0 on success */
if (!vc)
return -ENOMEM;
vc_cons[currcons].d = vc;
+ tty_port_init(&vc->port);
INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
visual_init(vc, currcons, 1);
if (!*vc->vc_uni_pagedir_loc)
@@ -831,9 +848,10 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
unsigned int cols, unsigned int lines)
{
unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
+ unsigned long end;
unsigned int old_cols, old_rows, old_row_size, old_screen_size;
unsigned int new_cols, new_rows, new_row_size, new_screen_size;
- unsigned int end, user;
+ unsigned int user;
unsigned short *newscreen;
WARN_CONSOLE_UNLOCKED();
@@ -956,12 +974,12 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
* Resize a virtual console as seen from the console end of things. We
* use the common vc_do_resize methods to update the structures. The
* caller must hold the console sem to protect console internals and
- * vc->vc_tty
+ * vc->port.tty
*/
int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
{
- return vc_do_resize(vc->vc_tty, vc, cols, rows);
+ return vc_do_resize(vc->port.tty, vc, cols, rows);
}
/**
@@ -1789,8 +1807,8 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
vc->vc_state = ESnormal;
return;
case ESpalette:
- if ( (c>='0'&&c<='9') || (c>='A'&&c<='F') || (c>='a'&&c<='f') ) {
- vc->vc_par[vc->vc_npar++] = (c > '9' ? (c & 0xDF) - 'A' + 10 : c - '0');
+ if (isxdigit(c)) {
+ vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
if (vc->vc_npar == 7) {
int i = vc->vc_par[0] * 3, j = 1;
vc->vc_palette[i] = 16 * vc->vc_par[j++];
@@ -2498,7 +2516,7 @@ static void vt_console_print(struct console *co, const char *b, unsigned count)
goto quit;
}
- if (vc->vc_mode != KD_TEXT)
+ if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
goto quit;
/* undraw cursor first */
@@ -2604,8 +2622,6 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
return -EFAULT;
ret = 0;
- lock_kernel();
-
switch (type)
{
case TIOCL_SETSEL:
@@ -2680,7 +2696,6 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
ret = -EINVAL;
break;
}
- unlock_kernel();
return ret;
}
@@ -2793,12 +2808,12 @@ static int con_open(struct tty_struct *tty, struct file *filp)
struct vc_data *vc = vc_cons[currcons].d;
/* Still being freed */
- if (vc->vc_tty) {
+ if (vc->port.tty) {
release_console_sem();
return -ERESTARTSYS;
}
tty->driver_data = vc;
- vc->vc_tty = tty;
+ vc->port.tty = tty;
if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
@@ -2826,7 +2841,7 @@ static void con_shutdown(struct tty_struct *tty)
struct vc_data *vc = tty->driver_data;
BUG_ON(vc == NULL);
acquire_console_sem();
- vc->vc_tty = NULL;
+ vc->port.tty = NULL;
release_console_sem();
tty_shutdown(tty);
}
@@ -2908,6 +2923,7 @@ static int __init con_init(void)
for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
+ tty_port_init(&vc->port);
visual_init(vc, currcons, 1);
vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
vc_init(vc, vc->vc_rows, vc->vc_cols,
@@ -3059,7 +3075,8 @@ static int bind_con_driver(const struct consw *csw, int first, int last,
old_was_color = vc->vc_can_do_color;
vc->vc_sw->con_deinit(vc);
- vc->vc_origin = (unsigned long)vc->vc_screenbuf;
+ if (!vc->vc_origin)
+ vc->vc_origin = (unsigned long)vc->vc_screenbuf;
visual_init(vc, i, 0);
set_origin(vc);
update_attr(vc);
@@ -3414,6 +3431,80 @@ 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;
+ saved_console_blanked = console_blanked;
+ 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;
+ console_blanked = saved_console_blanked;
+ 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
@@ -3703,7 +3794,8 @@ void do_unblank_screen(int leaving_gfx)
return;
}
vc = vc_cons[fg_console].d;
- if (vc->vc_mode != KD_TEXT)
+ /* Try to unblank in oops case too */
+ if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
return; /* but leave console_blanked != 0 */
if (blankinterval) {
@@ -3712,7 +3804,7 @@ void do_unblank_screen(int leaving_gfx)
}
console_blanked = 0;
- if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
+ if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc))
/* Low-level driver cannot restore -> do it ourselves */
update_screen(vc);
if (console_blank_hook)