2009-01-11 19:16:47

by Tomas Szepe

[permalink] [raw]
Subject: [PATCH] Morse code panics for 2.6.29-rc1

Bumped into this silly thing (morse code panics) by accident after
6 years or so, and couldn't resist updating it for a recent kernel.
So, here goes, enjoy.

Patch against 2.6.29-rc1.

--
Tomas Szepe <[email protected]>


diff -urN a/drivers/char/keyboard.c b/drivers/char/keyboard.c
--- a/drivers/char/keyboard.c 2008-12-25 00:26:37.000000000 +0100
+++ b/drivers/char/keyboard.c 2009-01-11 09:17:02.021500006 +0100
@@ -266,6 +266,27 @@
EXPORT_SYMBOL(kd_mksound);

/*
+ * Turn all possible leds on or off.
+ */
+void kd_set_led_all(int state)
+{
+ struct list_head *node;
+ state = state ? 1 : 0;
+
+ list_for_each(node, &kbd_handler.h_list) {
+ struct input_handle *handle = to_handle_h(node);
+ if (test_bit(EV_LED, handle->dev->evbit)) {
+ int led;
+ for (led = 0; led <= LED_MAX; led++) {
+ if (test_bit(led, handle->dev->ledbit))
+ input_event(handle->dev, EV_LED, led,
+ state);
+ }
+ }
+ }
+}
+
+/*
* Setting the keyboard rate.
*/

diff -urN a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
--- a/drivers/input/serio/i8042.c 2008-12-25 00:26:37.000000000 +0100
+++ b/drivers/input/serio/i8042.c 2009-01-11 09:35:26.538539743 +0100
@@ -59,10 +59,6 @@
module_param_named(noloop, i8042_noloop, bool, 0);
MODULE_PARM_DESC(noloop, "Disable the AUX Loopback command while probing for the AUX port");

-static unsigned int i8042_blink_frequency = 500;
-module_param_named(panicblink, i8042_blink_frequency, uint, 0600);
-MODULE_PARM_DESC(panicblink, "Frequency with which keyboard LEDs should blink when kernel panics");
-
#ifdef CONFIG_X86
static unsigned int i8042_dritek;
module_param_named(dritek, i8042_dritek, bool, 0);
@@ -838,53 +834,6 @@
printk(KERN_WARNING "i8042.c: Can't restore CTR.\n");
}

-
-/*
- * i8042_panic_blink() will flash the keyboard LEDs and is called when
- * kernel panics. Flashing LEDs is useful for users running X who may
- * not see the console and will help distingushing panics from "real"
- * lockups.
- *
- * Note that DELAY has a limit of 10ms so we will not get stuck here
- * waiting for KBC to free up even if KBD interrupt is off
- */
-
-#define DELAY do { mdelay(1); if (++delay > 10) return delay; } while(0)
-
-static long i8042_panic_blink(long count)
-{
- long delay = 0;
- static long last_blink;
- static char led;
-
- /*
- * We expect frequency to be about 1/2s. KDB uses about 1s.
- * Make sure they are different.
- */
- if (!i8042_blink_frequency)
- return 0;
- if (count - last_blink < i8042_blink_frequency)
- return 0;
-
- led ^= 0x01 | 0x04;
- while (i8042_read_status() & I8042_STR_IBF)
- DELAY;
- dbg("%02x -> i8042 (panic blink)", 0xed);
- i8042_suppress_kbd_ack = 2;
- i8042_write_data(0xed); /* set leds */
- DELAY;
- while (i8042_read_status() & I8042_STR_IBF)
- DELAY;
- DELAY;
- dbg("%02x -> i8042 (panic blink)", led);
- i8042_write_data(led);
- DELAY;
- last_blink = count;
- return delay;
-}
-
-#undef DELAY
-
#ifdef CONFIG_X86
static void i8042_dritek_enable(void)
{
@@ -1266,8 +1215,6 @@
if (err)
goto err_free_device;

- panic_blink = i8042_panic_blink;
-
return 0;

err_free_device:
@@ -1285,8 +1232,6 @@
platform_device_unregister(i8042_platform_device);
platform_driver_unregister(&i8042_driver);
i8042_platform_exit();
-
- panic_blink = NULL;
}

module_init(i8042_init);
diff -urN a/include/linux/kernel.h b/include/linux/kernel.h
--- a/include/linux/kernel.h 2009-01-11 09:48:24.998469846 +0100
+++ b/include/linux/kernel.h 2009-01-11 09:34:15.220568324 +0100
@@ -157,7 +157,6 @@
#endif

extern struct atomic_notifier_head panic_notifier_list;
-extern long (*panic_blink)(long time);
NORET_TYPE void panic(const char * fmt, ...)
__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
extern void oops_enter(void);
diff -urN a/include/linux/morseops.h b/include/linux/morseops.h
--- a/include/linux/morseops.h 1970-01-01 01:00:00.000000000 +0100
+++ b/include/linux/morseops.h 2009-01-11 09:17:02.021500006 +0100
@@ -0,0 +1,23 @@
+/* Yes, it's morse code ops indeed. */
+
+#ifndef _LINUX_MORSEOPS_H
+#define _LINUX_MORSEOPS_H
+
+#include <linux/autoconf.h>
+
+#ifdef CONFIG_MORSE_PANICS
+
+extern const unsigned char morsetable[]; /* in kernel/morse.c */
+void panic_morseblink(char *buf); /* in kernel/morse.c */
+
+static inline unsigned char tomorse(char c) {
+ if (c >= 'a' && c <= 'z')
+ c -= 'a' - 'A';
+ return (c >= '"' && c <= '_') ? morsetable[c - '"'] : 0;
+}
+
+#else /* CONFIG_MORSE_PANICS */
+# define panic_morseblink(buf) do { } while (0)
+#endif /* CONFIG_MORSE_PANICS */
+
+#endif /* _LINUX_MORSEOPS_H */
diff -urN a/include/linux/vt_kern.h b/include/linux/vt_kern.h
--- a/include/linux/vt_kern.h 2008-12-25 00:26:37.000000000 +0100
+++ b/include/linux/vt_kern.h 2009-01-11 09:17:02.021500006 +0100
@@ -26,7 +26,10 @@
#define BROKEN_GRAPHICS_PROGRAMS 1
#endif

+/* keyboard.c */
+
extern void kd_mksound(unsigned int hz, unsigned int ticks);
+extern void kd_set_led_all(int state);
extern int kbd_rate(struct kbd_repeat *rep);
extern int fg_console, last_console, want_console;

diff -urN a/init/Kconfig b/init/Kconfig
--- a/init/Kconfig 2009-01-11 09:48:25.058469650 +0100
+++ b/init/Kconfig 2009-01-11 09:17:02.021500006 +0100
@@ -860,6 +860,21 @@

source "arch/Kconfig"

+config MORSE_PANICS
+ bool "Morse code panics"
+ depends on VT
+ help
+ When enabled, this code will make a panicking kernel cry for
+ help in morse code, signalling on the leds of a possibly attached
+ keyboard and/or a bleeper. You can enable/disable your morse
+ output devices of choice using the "panicmorse" kernel boot
+ parameter. Currently, "panicmorse=0" will disable the signalling
+ completely, "panicmorse=1" (the default) will only blink the leds,
+ "panicmorse=2" will only beep, and "panicmorse=3" will do both.
+
+ If unsure, say Y. This feature is very helpful to those who
+ spend most of their time in X.
+
endmenu # General setup

config HAVE_GENERIC_DMA_COHERENT
diff -urN a/kernel/Makefile b/kernel/Makefile
--- a/kernel/Makefile 2009-01-11 09:48:25.068467569 +0100
+++ b/kernel/Makefile 2009-01-11 09:18:14.378515494 +0100
@@ -62,6 +62,7 @@
obj-$(CONFIG_PID_NS) += pid_namespace.o
obj-$(CONFIG_IKCONFIG) += configs.o
obj-$(CONFIG_RESOURCE_COUNTERS) += res_counter.o
+obj-$(CONFIG_MORSE_PANICS) += morse.o
obj-$(CONFIG_STOP_MACHINE) += stop_machine.o
obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
diff -urN a/kernel/morse.c b/kernel/morse.c
--- a/kernel/morse.c 1970-01-01 01:00:00.000000000 +0100
+++ b/kernel/morse.c 2009-01-11 09:39:05.692604924 +0100
@@ -0,0 +1,234 @@
+/*
+ * kernel/morse.c
+ *
+ * Copyright (C) 2002 Andrew Rodland <[email protected]>
+ * Copyright (C) 2003, 2009 Tomas Szepe <[email protected]>
+ *
+ * Tell the user who may be running in X and not see the console that
+ * we have panic'd. This is to distingush panics from "real lockups."
+ * Could in theory send the panic message as morse, but that is left
+ * as an exercise for the reader.
+ *
+ * And now it's done! LED and speaker morse code by Andrew Rodland
+ * <[email protected]>, with improvements based on suggestions from
+ * [email protected] and a host of others.
+ *
+ * Initial 2.5 morsepanics port and cleanup by
+ * Tomas Szepe <[email protected]>, January 2003.
+ *
+ * Cryptic morse code table replaced with meticulous macrowork by
+ * Jan-Benedict Glaw <[email protected]>, February 2003.
+ *
+ * Updated for 2.6.29-rc1 by
+ * Tomas Szepe <[email protected]>, January 2009.
+ */
+
+#include <linux/autoconf.h>
+#include <linux/morseops.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/vt_kern.h>
+
+#define DITLEN (HZ / 5)
+#define DAHLEN (3 * DITLEN)
+#define SPACELEN (7 * DITLEN)
+#define FREQ 844
+
+#define MORSE_OUTPUT_BLINK (1 << 0)
+#define MORSE_OUTPUT_BLEEP (1 << 1)
+#define MORSE_OUTPUT_ESTRADE (MORSE_OUTPUT_BLINK | MORSE_OUTPUT_BLEEP)
+
+static int morse_setting = MORSE_OUTPUT_BLINK;
+
+/* The following macros are used to make up the morse code table. */
+
+#define IS_DASH(letter, shift) \
+ ((letter) == '-' ? (1 << (shift)) : (0 << (shift)))
+#define MORSE(shift, b1, b2, b3, b4, b5, b6) \
+ (1 << (shift) | IS_DASH((b1), 5) | IS_DASH((b2), 4) \
+ | IS_DASH((b3), 3) | IS_DASH((b4), 2) \
+ | IS_DASH((b5), 1) | IS_DASH((b6), 0))
+#define MORSE0(letter) \
+ (0)
+#define MORSE1(letter, b1) \
+ MORSE(1, '.', '.', '.', '.', '.', (b1))
+#define MORSE2(letter, b1, b2) \
+ MORSE(2, '.', '.', '.', '.', (b1), (b2))
+#define MORSE3(letter, b1, b2, b3) \
+ MORSE(3, '.', '.', '.', (b1), (b2), (b3))
+#define MORSE4(letter, b1, b2, b3, b4) \
+ MORSE(4, '.', '.', (b1), (b1), (b3), (b4))
+#define MORSE5(letter, b1, b2, b3, b4, b5) \
+ MORSE(5, '.', (b1), (b2), (b3), (b4), (b5))
+#define MORSE6(letter, b1, b2, b3, b4, b5, b6) \
+ MORSE(6, (b1), (b2), (b3), (b4), (b5), (b6))
+
+/* Do not shuffle things about in here, the order matters. */
+const unsigned char morsetable[] = {
+
+ /* 0122, 0, 0310, 0, 0, 0163, "#$%&' */
+ MORSE6('"', '-', '.', '-', '-', '.', '-'),
+ MORSE0('#'),
+ 0310, /* '$': FIXME */
+ MORSE0('%'),
+ MORSE0('&'),
+ MORSE6('\'', '-', '.', '-', '.', '-', '-'),
+
+ /* 055, 0155, 0, 0, 0163, 0141, 0152, 0051, ()*+,-./ */
+ MORSE5('(', '-', '.', '-', '-', '.'),
+ MORSE6(')', '-', '.', '-', '-', '.', '-'),
+ MORSE0('*'),
+
+ /* http://www.vennfuessler.de/service/technik/morsen.html */
+ MORSE5('+', '.', '-', '.', '-', '.'),
+
+ MORSE6(',', '-', '-', '.', '.', '.', '-'),
+ MORSE6('-', '-', '.', '.', '.', '.', '-'),
+ MORSE6('.', '.', '-', '.', '-', '.', '-'),
+ MORSE5('/', '-', '.', '.', '-', '.'),
+
+ /* 077, 076, 074, 070, 060, 040, 041, 043, 047, 057, 0-9 */
+ MORSE5('0', '-', '-', '-', '-', '-'),
+ MORSE5('1', '.', '-', '-', '-', '-'),
+ MORSE5('2', '.', '.', '-', '-', '-'),
+ MORSE5('3', '.', '.', '.', '-', '-'),
+ MORSE5('4', '.', '.', '.', '.', '-'),
+ MORSE5('5', '.', '.', '.', '.', '.'),
+ MORSE5('6', '-', '.', '.', '.', '.'),
+ MORSE5('7', '-', '-', '.', '.', '.'),
+ MORSE5('8', '-', '-', '-', '.', '.'),
+ MORSE5('9', '-', '-', '-', '-', '.'),
+
+ /* 0107, 0125, 0, 0061, 0, 0114, 0, :;<=>?@ */
+ MORSE6(':', '-', '-', '-', '.', '.', '.'),
+ MORSE6(';', '-', '.', '-', '.', '-', '.'),
+ MORSE0('<'),
+ MORSE5('=', '-', '.', '.', '.', '-'),
+ MORSE0('>'),
+ MORSE6('?', '.', '.', '-', '-', '.', '.'),
+ MORSE0('@'),
+
+ /* 006, 021, 025, 011, 002, 024, 013, 020, 004, A-I */
+ MORSE2('A', '.', '-'),
+ MORSE4('B', '-', '.', '.', '.'),
+ MORSE4('C', '-', '.', '-', '.'),
+ MORSE3('D', '-', '.', '.'),
+ MORSE1('E', '.'),
+ MORSE4('F', '.', '.', '-', '.'),
+ MORSE3('G', '-', '-', '.'),
+ MORSE4('H', '.', '.', '.', '.'),
+ MORSE2('I', '.', '.'),
+
+ /* 036, 015, 022, 007, 005, 017, 026, 033, 012, J-R */
+ MORSE4('J', '.', '-', '-', '-'),
+ MORSE3('K', '-', '.', '-'),
+ MORSE4('L', '.', '-', '.', '.'),
+ MORSE2('M', '-', '-'),
+ MORSE2('N', '-', '.'),
+ MORSE3('O', '-', '-', '-'),
+ MORSE4('P', '.', '-', '-', '.'),
+ MORSE4('Q', '-', '-', '.', '-'),
+ MORSE3('R', '.', '-', '.'),
+
+ /* 010, 003, 014, 030, 016, 031, 035, 023, S-Z */
+ MORSE3('S', '.', '.', '.'),
+ MORSE1('T', '-'),
+ MORSE3('U', '.', '.', '-'),
+ MORSE4('V', '.', '.', '.', '-'),
+ MORSE3('W', '.', '-', '-'),
+ MORSE4('X', '-', '.', '.', '-'),
+ MORSE4('Y', '-', '.', '-', '-'),
+ MORSE4('Z', '-', '-', '.', '.'),
+
+ /* 0, 0, 0, 0, 0154 [\]^_ */
+ MORSE0('['),
+ MORSE0('\\'),
+ MORSE0(']'),
+ MORSE0('^'),
+ MORSE6('_', '.', '-', '-', '-', '.', '-'),
+};
+
+void panic_morseblink(char *buf)
+{
+ static unsigned long next_jiffie = 0;
+ static char *bufpos = 0;
+ static unsigned char morse = 0;
+ static char state = 1;
+
+ if (!(morse_setting & MORSE_OUTPUT_ESTRADE))
+ return;
+
+ if (!buf)
+ buf = "Uh oh, we lost the panic msg.";
+
+ /* Waiting for something? */
+ if (bufpos && time_after(next_jiffie, jiffies))
+ return;
+
+ if (state) { /* Coming off of a blink. */
+ if (morse_setting & MORSE_OUTPUT_BLINK)
+ kd_set_led_all(0);
+
+ state = 0;
+
+ if (morse > 1) {
+ /* Not done yet, just a one-dit pause. */
+ next_jiffie = jiffies + DITLEN;
+ } else {
+ /* Get a new char, figure out how much space. */
+
+ /* First time through. */
+ if (!bufpos)
+ bufpos = buf;
+
+ if (!*bufpos) {
+ /* Repeating. */
+ bufpos = buf;
+ next_jiffie = jiffies + SPACELEN;
+ } else {
+ /* Inter-letter space. */
+ next_jiffie = jiffies + DAHLEN;
+ }
+
+ if (!(morse = tomorse(*bufpos))) {
+ next_jiffie = jiffies + SPACELEN;
+ state = 1; /* And get us back here. */
+ }
+ bufpos++;
+ }
+ } else {
+ /* Starting a new blink. We have a valid code in morse. */
+ int len;
+
+ len = (morse & 0x01) ? DAHLEN : DITLEN;
+
+ if (morse_setting & MORSE_OUTPUT_BLEEP)
+ kd_mksound(FREQ, len);
+
+ if (morse_setting & MORSE_OUTPUT_BLINK)
+ kd_set_led_all(1);
+
+ next_jiffie = jiffies + len;
+
+ state = 1;
+ morse >>= 1;
+ }
+}
+
+static int __init panicmorse_setup(char *str)
+{
+ int par;
+
+ if (get_option(&str, &par))
+ morse_setting = par;
+
+ return 1;
+}
+
+/* "panicmorse=0" disables the blinking as it caused problems with
+ * certain console switches.
+ *
+ * "panicmorse | 1" does the show using kbd leds.
+ * "panicmorse | 2" throws in bleeping via kd_mksound().
+ */
+__setup("panicmorse=", panicmorse_setup);
diff -urN a/kernel/panic.c b/kernel/panic.c
--- a/kernel/panic.c 2009-01-11 09:48:25.088467527 +0100
+++ b/kernel/panic.c 2009-01-11 09:47:59.108672887 +0100
@@ -22,6 +22,7 @@
#include <linux/random.h>
#include <linux/kallsyms.h>
#include <linux/dmi.h>
+#include <linux/morseops.h>

int panic_on_oops;
static unsigned long tainted_mask;
@@ -35,15 +36,6 @@

EXPORT_SYMBOL(panic_notifier_list);

-static long no_blink(long time)
-{
- return 0;
-}
-
-/* Returns how long it waited in ms */
-long (*panic_blink)(long time);
-EXPORT_SYMBOL(panic_blink);
-
/**
* panic - halt the system
* @fmt: The text string to print
@@ -94,9 +86,6 @@

atomic_notifier_call_chain(&panic_notifier_list, 0, buf);

- if (!panic_blink)
- panic_blink = no_blink;
-
if (panic_timeout > 0) {
/*
* Delay timeout seconds before rebooting the machine.
@@ -105,7 +94,7 @@
printk(KERN_EMERG "Rebooting in %d seconds..",panic_timeout);
for (i = 0; i < panic_timeout*1000; ) {
touch_nmi_watchdog();
- i += panic_blink(i);
+ panic_morseblink(buf);
mdelay(1);
i++;
}
@@ -127,11 +116,10 @@
disabled_wait(caller);
#endif
local_irq_enable();
- for (i = 0;;) {
+ for (;;) {
touch_softlockup_watchdog();
- i += panic_blink(i);
+ panic_morseblink(buf);
mdelay(1);
- i++;
}
}


2009-01-11 20:22:53

by Andi Kleen

[permalink] [raw]
Subject: Re: [PATCH] Morse code panics for 2.6.29-rc1

Tomas Szepe <[email protected]> writes:
> +
> +static inline unsigned char tomorse(char c) {
> + if (c >= 'a' && c <= 'z')
> + c -= 'a' - 'A';

It's not widely known, but the kernel actually has a
fully usable ctype.h

-Andi
--
[email protected]

2009-01-16 14:10:25

by Johannes Schindelin

[permalink] [raw]
Subject: Re: [PATCH] Morse code panics for 2.6.29-rc1

Tomas Szepe <szepe <at> pinerecords.com> writes:

>
> Bumped into this silly thing (morse code panics) by accident after
> 6 years or so, and couldn't resist updating it for a recent kernel.
> So, here goes, enjoy.
>
> Patch against 2.6.29-rc1.

Did you not mean to make compilation i8042_panic_blink() dependent on
!CONFIG_MORSE_PANICS instead of removing it?

Ciao,
Dscho



2009-01-18 08:43:14

by Pavel Machek

[permalink] [raw]
Subject: Re: [PATCH] Morse code panics for 2.6.29-rc1

On Sun 2009-01-11 20:05:03, Tomas Szepe wrote:
> Bumped into this silly thing (morse code panics) by accident after
> 6 years or so, and couldn't resist updating it for a recent kernel.
> So, here goes, enjoy.
>
> Patch against 2.6.29-rc1.

Add a signed-off-by and try to merge it. Slightly crazy, but it is
more useful than just blinking leds...

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html