Three things.
- Adds lib/bust_spinlocks.c for architectures which don't
provide bust_spinlocks() .
- Closes a race between tioclinux() and console scrolling
which was leaving bits of stuff on the screen when the
mouse was used with gpm.
- Added a missing break statement in do_syslog() (James Simmons)
Patch against -ac20 is here. The full `remove console_lock' patch
against 2.4.3-pre4 is at http://www.uow.edu.au/~andrewm/linux/console.html
--- linux-2.4.2-ac20/drivers/char/console.c Tue Mar 13 20:29:21 2001
+++ ac/drivers/char/console.c Tue Mar 13 21:12:47 2001
@@ -69,6 +69,9 @@
*
* Removed old-style timers, introduced console_timer, made timer
* deletion SMP-safe. 17Jun00, Andrew Morton <[email protected]>
+ *
+ * Removed console_lock, enabled interrupts across all console operations
+ * 13 March 2001, Andrew Morton
*/
#include <linux/module.h>
@@ -1034,6 +1037,7 @@
color = def_color;
}
+/* console_sem is held */
static void csi_m(int currcons)
{
int i;
@@ -1173,6 +1177,7 @@
return report_mouse;
}
+/* console_sem is held */
static void set_mode(int currcons, int on_off)
{
int i;
@@ -1238,6 +1243,7 @@
}
}
+/* console_sem is held */
static void setterm_command(int currcons)
{
switch(par[0]) {
@@ -1292,19 +1298,7 @@
}
}
-static void insert_line(int currcons, unsigned int nr)
-{
- scrdown(currcons,y,bottom,nr);
- need_wrap = 0;
-}
-
-
-static void delete_line(int currcons, unsigned int nr)
-{
- scrup(currcons,y,bottom,nr);
- need_wrap = 0;
-}
-
+/* console_sem is held */
static void csi_at(int currcons, unsigned int nr)
{
if (nr > video_num_columns - x)
@@ -1314,15 +1308,18 @@
insert_char(currcons, nr);
}
+/* console_sem is held */
static void csi_L(int currcons, unsigned int nr)
{
if (nr > video_num_lines - y)
nr = video_num_lines - y;
else if (!nr)
nr = 1;
- insert_line(currcons, nr);
+ scrdown(currcons,y,bottom,nr);
+ need_wrap = 0;
}
+/* console_sem is held */
static void csi_P(int currcons, unsigned int nr)
{
if (nr > video_num_columns - x)
@@ -1332,15 +1329,18 @@
delete_char(currcons, nr);
}
+/* console_sem is held */
static void csi_M(int currcons, unsigned int nr)
{
if (nr > video_num_lines - y)
nr = video_num_lines - y;
else if (!nr)
nr=1;
- delete_line(currcons, nr);
+ scrup(currcons,y,bottom,nr);
+ need_wrap = 0;
}
+/* console_sem is held (except via vc_init->reset_terminal */
static void save_cur(int currcons)
{
saved_x = x;
@@ -1355,6 +1355,7 @@
saved_G1 = G1_charset;
}
+/* console_sem is held */
static void restore_cur(int currcons)
{
gotoxy(currcons,saved_x,saved_y);
@@ -1375,6 +1376,7 @@
EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
ESpalette };
+/* console_sem is held (except via vc_init()) */
static void reset_terminal(int currcons, int do_clear)
{
top = 0;
@@ -1430,6 +1432,7 @@
csi_J(currcons,2);
}
+/* console_sem is held */
static void do_con_trol(struct tty_struct *tty, unsigned int currcons, int c)
{
/*
@@ -1810,6 +1813,7 @@
#define CON_BUF_SIZE PAGE_SIZE
DECLARE_MUTEX(con_buf_sem);
+/* acquires console_sem */
static int do_con_write(struct tty_struct * tty, int from_user,
const unsigned char *buf, int count)
{
@@ -2049,7 +2053,7 @@
void set_console(int nr)
{
want_console = nr;
- schedule_task(&console_callback_tq);
+ schedule_console_callback();
}
#ifdef CONFIG_VT_CONSOLE
@@ -2171,9 +2175,21 @@
* Handling of Linux-specific VC ioctls
*/
+/*
+ * Generally a bit racy with respect to console_sem().
+ *
+ * There are some functions which don't need it.
+ *
+ * There are some functions which can sleep for arbitrary periods (paste_selection)
+ * but we don't need the lock there anyway.
+ *
+ * set_selection has locking, and definitely needs it
+ */
+
int tioclinux(struct tty_struct *tty, unsigned long arg)
{
char type, data;
+ int ret;
if (tty->driver.type != TTY_DRIVER_TYPE_CONSOLE)
return -EINVAL;
@@ -2181,17 +2197,23 @@
return -EPERM;
if (get_user(type, (char *)arg))
return -EFAULT;
+ ret = 0;
switch (type)
{
case 2:
- return set_selection(arg, tty, 1);
+ acquire_console_sem();
+ ret = set_selection(arg, tty, 1);
+ release_console_sem();
+ break;
case 3:
- return paste_selection(tty);
+ ret = paste_selection(tty);
+ break;
case 4:
unblank_screen();
- return 0;
+ break;
case 5:
- return sel_loadlut(arg);
+ ret = sel_loadlut(arg);
+ break;
case 6:
/*
@@ -2201,24 +2223,33 @@
* related to the kernel should not use this.
*/
data = shift_state;
- return __put_user(data, (char *) arg);
+ ret = __put_user(data, (char *) arg);
+ break;
case 7:
data = mouse_reporting();
- return __put_user(data, (char *) arg);
+ ret = __put_user(data, (char *) arg);
+ break;
case 10:
set_vesa_blanking(arg);
- return 0;
+ break;;
case 11: /* set kmsg redirect */
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
- if (get_user(data, (char *)arg+1))
- return -EFAULT;
- kmsg_redirect = data;
- return 0;
+ if (!capable(CAP_SYS_ADMIN)) {
+ ret = -EPERM;
+ } else {
+ if (get_user(data, (char *)arg+1))
+ ret = -EFAULT;
+ else
+ kmsg_redirect = data;
+ }
+ break;
case 12: /* get fg_console */
- return fg_console;
+ ret = fg_console;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
}
- return -EINVAL;
+ return ret;
}
/*
--- linux-2.4.2-ac20/drivers/video/fbcon.c Tue Mar 13 20:29:28 2001
+++ ac/drivers/video/fbcon.c Tue Mar 13 21:11:29 2001
@@ -1149,8 +1149,8 @@
start++;
}
}
- console_conditional_schedule();
scr_writew(c, d);
+ console_conditional_schedule();
s++;
d++;
} while (s < le);
--- linux-2.4.2-ac20/kernel/printk.c Tue Mar 13 20:29:30 2001
+++ ac/kernel/printk.c Thu Mar 15 18:12:46 2001
@@ -267,6 +267,7 @@
spin_lock_irq(&logbuf_lock);
error = log_end - log_start;
spin_unlock_irq(&logbuf_lock);
+ break;
default:
error = -EINVAL;
break;
--- linux-2.4.2-ac20/lib/Makefile Sat Dec 30 09:07:24 2000
+++ ac/lib/Makefile Thu Mar 15 18:26:19 2001
@@ -10,7 +10,7 @@
export-objs := cmdline.o
-obj-y := errno.o ctype.o string.o vsprintf.o brlock.o cmdline.o
+obj-y := errno.o ctype.o string.o vsprintf.o brlock.o cmdline.o bust_spinlocks.o
ifneq ($(CONFIG_HAVE_DEC_LOCK),y)
obj-y += dec_and_lock.o
--- linux-2.4.2-ac20/lib/bust_spinlocks.c Thu Jan 1 00:00:00 1970
+++ ac/lib/bust_spinlocks.c Thu Mar 15 18:28:28 2001
@@ -0,0 +1,38 @@
+/*
+ * lib/bust_spinlocks.c
+ *
+ * Provides a minimal bust_spinlocks for architectures which don't have one of their own.
+ *
+ * bust_spinlocks() clears any spinlocks which would prevent oops, die(), BUG()
+ * and panic() information from reaching the user.
+ */
+
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/tty.h>
+#include <linux/wait.h>
+#include <linux/vt_kern.h>
+
+extern spinlock_t timerlist_lock;
+
+void bust_spinlocks(int yes)
+{
+ spin_lock_init(&timerlist_lock);
+ if (yes) {
+ oops_in_progress = 1;
+ } else {
+ int loglevel_save = console_loglevel;
+ unblank_screen();
+ oops_in_progress = 0;
+ /*
+ * OK, the message is on the console. Now we call printk()
+ * without oops_in_progress set so that printk will give klogd
+ * and the blankded console a poke. Hold onto your hats...
+ */
+ console_loglevel = 15; /* NMI oopser may have shut the console up */
+ printk(" ");
+ console_loglevel = loglevel_save;
+ }
+}
+
+