Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-kgdb

* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-kgdb:
  kgdb: always use icache flush for sw breakpoints
  kgdb: fix SMP NMI kgdb_handle_exception exit race
  kgdb: documentation fixes
  kgdb: allow static kgdbts boot configuration
  kgdb: add documentation
  kgdb: Kconfig fix
  kgdb: add kgdb internal test suite
  kgdb: fix several kgdb regressions
  kgdb: kgdboc pl011 I/O module
  kgdb: fix optional arch functions and probe_kernel_*
  kgdb: add x86 HW breakpoints
  kgdb: print breakpoint removed on exception
  kgdb: clocksource watchdog
  kgdb: fix NMI hangs
  kgdb: fix kgdboc dynamic module configuration
  kgdb: document parameters
  x86: kgdb support
  consoles: polling support, kgdboc
  kgdb: core
  uaccess: add probe_kernel_write()

Documentation/DocBook/Makefile

@@ -9,7 +9,7 @@
 DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \
 	    kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
 	    procfs-guide.xml writing_usb_driver.xml networking.xml \
-	    kernel-api.xml filesystems.xml lsm.xml usb.xml \
+	    kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
 	    gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
 	    genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml
 

Documentation/kernel-parameters.txt

@@ -941,6 +941,11 @@ and is between 256 and 4096 characters. It is defined in the file
 	kstack=N	[X86-32,X86-64] Print N words from the kernel stack
 			in oops dumps.
 
+	kgdboc=		[HW] kgdb over consoles.
+			Requires a tty driver that supports console polling.
+			(only serial suported for now)
+			Format: <serial_device>[,baud]
+
 	l2cr=		[PPC]
 
 	lapic		[X86-32,APIC] Enable the local APIC even if BIOS

MAINTAINERS

@@ -2319,6 +2319,12 @@ L:	linux-kernel@vger.kernel.org
 L:	kexec@lists.infradead.org
 S:	Maintained
 
+KGDB
+P:	Jason Wessel
+M:	jason.wessel@windriver.com
+L:	kgdb-bugreport@lists.sourceforge.net
+S:	Maintained
+
 KPROBES
 P:	Ananth N Mavinakayanahalli
 M:	ananth@in.ibm.com

arch/x86/Kconfig

@@ -23,6 +23,7 @@ config X86
 	select HAVE_KPROBES
 	select HAVE_KRETPROBES
 	select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
+	select HAVE_ARCH_KGDB
 
 
 config GENERIC_LOCKBREAK

arch/x86/kernel/Makefile

@@ -67,6 +67,7 @@ obj-$(CONFIG_MODULES)		+= module_$(BITS).o
 obj-$(CONFIG_ACPI_SRAT) 	+= srat_32.o
 obj-$(CONFIG_EFI) 		+= efi.o efi_$(BITS).o efi_stub_$(BITS).o
 obj-$(CONFIG_DOUBLEFAULT) 	+= doublefault_32.o
+obj-$(CONFIG_KGDB)		+= kgdb.o
 obj-$(CONFIG_VM86)		+= vm86_32.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 

arch/x86/kernel/setup64.c

@@ -11,6 +11,7 @@
 #include <linux/bootmem.h>
 #include <linux/bitops.h>
 #include <linux/module.h>
+#include <linux/kgdb.h>
 #include <asm/pda.h>
 #include <asm/pgtable.h>
 #include <asm/processor.h>
@@ -251,6 +252,17 @@ void __cpuinit cpu_init (void)
 	load_TR_desc();
 	load_LDT(&init_mm.context);
 
+#ifdef CONFIG_KGDB
+	/*
+	 * If the kgdb is connected no debug regs should be altered.  This
+	 * is only applicable when KGDB and a KGDB I/O module are built
+	 * into the kernel and you are using early debugging with
+	 * kgdbwait. KGDB will control the kernel HW breakpoint registers.
+	 */
+	if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
+		arch_kgdb_ops.correct_hw_break();
+	else {
+#endif
 	/*
 	 * Clear all 6 debug registers:
 	 */
@@ -261,6 +273,10 @@ void __cpuinit cpu_init (void)
 	set_debugreg(0UL, 3);
 	set_debugreg(0UL, 6);
 	set_debugreg(0UL, 7);
+#ifdef CONFIG_KGDB
+	/* If the kgdb is connected no debug regs should be altered. */
+	}
+#endif
 
 	fpu_init(); 
 

arch/x86/kernel/traps_32.c

@@ -730,6 +730,8 @@ io_check_error(unsigned char reason, struct pt_regs *regs)
 static __kprobes void
 unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
 {
+	if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
+		return;
 #ifdef CONFIG_MCA
 	/*
 	 * Might actually be able to figure out what the guilty party

arch/x86/kernel/traps_64.c

@@ -602,8 +602,13 @@ void die(const char * str, struct pt_regs * regs, long err)
 
 void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
 {
-	unsigned long flags = oops_begin();
+	unsigned long flags;
 
+	if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) ==
+	    NOTIFY_STOP)
+		return;
+
+	flags = oops_begin();
 	/*
 	 * We are in trouble anyway, lets at least try
 	 * to get a message out.
@@ -808,6 +813,8 @@ io_check_error(unsigned char reason, struct pt_regs * regs)
 static __kprobes void
 unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
 {
+	if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
+		return;
 	printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
 		reason);
 	printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");

drivers/char/tty_io.c

@@ -1155,6 +1155,48 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index)
 	return NULL;
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+
+/**
+ *	tty_find_polling_driver	-	find device of a polled tty
+ *	@name: name string to match
+ *	@line: pointer to resulting tty line nr
+ *
+ *	This routine returns a tty driver structure, given a name
+ *	and the condition that the tty driver is capable of polled
+ *	operation.
+ */
+struct tty_driver *tty_find_polling_driver(char *name, int *line)
+{
+	struct tty_driver *p, *res = NULL;
+	int tty_line = 0;
+	char *str;
+
+	mutex_lock(&tty_mutex);
+	/* Search through the tty devices to look for a match */
+	list_for_each_entry(p, &tty_drivers, tty_drivers) {
+		str = name + strlen(p->name);
+		tty_line = simple_strtoul(str, &str, 10);
+		if (*str == ',')
+			str++;
+		if (*str == '\0')
+			str = 0;
+
+		if (tty_line >= 0 && tty_line <= p->num && p->poll_init &&
+				!p->poll_init(p, tty_line, str)) {
+
+			res = p;
+			*line = tty_line;
+			break;
+		}
+	}
+	mutex_unlock(&tty_mutex);
+
+	return res;
+}
+EXPORT_SYMBOL_GPL(tty_find_polling_driver);
+#endif
+
 /**
  *	tty_check_change	-	check for POSIX terminal changes
  *	@tty: tty to check
@@ -3850,6 +3892,11 @@ void tty_set_operations(struct tty_driver *driver,
 	driver->write_proc = op->write_proc;
 	driver->tiocmget = op->tiocmget;
 	driver->tiocmset = op->tiocmset;
+#ifdef CONFIG_CONSOLE_POLL
+	driver->poll_init = op->poll_init;
+	driver->poll_get_char = op->poll_get_char;
+	driver->poll_put_char = op->poll_put_char;
+#endif
 }
 
 

drivers/misc/Makefile

@@ -22,3 +22,4 @@ obj-$(CONFIG_FUJITSU_LAPTOP)	+= fujitsu-laptop.o
 obj-$(CONFIG_EEPROM_93CX6)	+= eeprom_93cx6.o
 obj-$(CONFIG_INTEL_MENLOW)	+= intel_menlow.o
 obj-$(CONFIG_ENCLOSURE_SERVICES) += enclosure.o
+obj-$(CONFIG_KGDB_TESTS)	+= kgdbts.o

drivers/serial/8250.c

@@ -1740,6 +1740,60 @@ static inline void wait_for_xmitr(struct uart_8250_port *up, int bits)
 	}
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+static int serial8250_get_poll_char(struct uart_port *port)
+{
+	struct uart_8250_port *up = (struct uart_8250_port *)port;
+	unsigned char lsr = serial_inp(up, UART_LSR);
+
+	while (!(lsr & UART_LSR_DR))
+		lsr = serial_inp(up, UART_LSR);
+
+	return serial_inp(up, UART_RX);
+}
+
+
+static void serial8250_put_poll_char(struct uart_port *port,
+			 unsigned char c)
+{
+	unsigned int ier;
+	struct uart_8250_port *up = (struct uart_8250_port *)port;
+
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = serial_in(up, UART_IER);
+	if (up->capabilities & UART_CAP_UUE)
+		serial_out(up, UART_IER, UART_IER_UUE);
+	else
+		serial_out(up, UART_IER, 0);
+
+	wait_for_xmitr(up, BOTH_EMPTY);
+	/*
+	 *	Send the character out.
+	 *	If a LF, also do CR...
+	 */
+	serial_out(up, UART_TX, c);
+	if (c == 10) {
+		wait_for_xmitr(up, BOTH_EMPTY);
+		serial_out(up, UART_TX, 13);
+	}
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up, BOTH_EMPTY);
+	serial_out(up, UART_IER, ier);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
 static int serial8250_startup(struct uart_port *port)
 {
 	struct uart_8250_port *up = (struct uart_8250_port *)port;
@@ -2386,6 +2440,10 @@ static struct uart_ops serial8250_pops = {
 	.request_port	= serial8250_request_port,
 	.config_port	= serial8250_config_port,
 	.verify_port	= serial8250_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = serial8250_get_poll_char,
+	.poll_put_char = serial8250_put_poll_char,
+#endif
 };
 
 static struct uart_8250_port serial8250_ports[UART_NR];

drivers/serial/Kconfig

@@ -961,6 +961,9 @@ config SERIAL_CORE
 config SERIAL_CORE_CONSOLE
 	bool
 
+config CONSOLE_POLL
+	bool
+
 config SERIAL_68328
 	bool "68328 serial support"
 	depends on M68328 || M68EZ328 || M68VZ328

drivers/serial/Makefile

@@ -66,4 +66,5 @@ obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o
 obj-$(CONFIG_SERIAL_NETX) += netx-serial.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
 obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o
+obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
 obj-$(CONFIG_SERIAL_QE) += ucc_uart.o

drivers/serial/amba-pl011.c

@@ -314,6 +314,32 @@ static void pl011_break_ctl(struct uart_port *port, int break_state)
 	spin_unlock_irqrestore(&uap->port.lock, flags);
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+static int pl010_get_poll_char(struct uart_port *port)
+{
+	struct uart_amba_port *uap = (struct uart_amba_port *)port;
+	unsigned int status;
+
+	do {
+		status = readw(uap->port.membase + UART01x_FR);
+	} while (status & UART01x_FR_RXFE);
+
+	return readw(uap->port.membase + UART01x_DR);
+}
+
+static void pl010_put_poll_char(struct uart_port *port,
+			 unsigned char ch)
+{
+	struct uart_amba_port *uap = (struct uart_amba_port *)port;
+
+	while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF)
+		barrier();
+
+	writew(ch, uap->port.membase + UART01x_DR);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
 static int pl011_startup(struct uart_port *port)
 {
 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
@@ -572,6 +598,10 @@ static struct uart_ops amba_pl011_pops = {
 	.request_port	= pl010_request_port,
 	.config_port	= pl010_config_port,
 	.verify_port	= pl010_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = pl010_get_poll_char,
+	.poll_put_char = pl010_put_poll_char,
+#endif
 };
 
 static struct uart_amba_port *amba_ports[UART_NR];

drivers/serial/kgdboc.c

+/*
+ * Based on the same principle as kgdboe using the NETPOLL api, this
+ * driver uses a console polling api to implement a gdb serial inteface
+ * which is multiplexed on a console port.
+ *
+ * Maintainer: Jason Wessel <jason.wessel@windriver.com>
+ *
+ * 2007-2008 (c) Jason Wessel - Wind River Systems, Inc.
+ *
+ * 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.
+ */
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+#include <linux/kgdb.h>
+#include <linux/tty.h>
+
+#define MAX_CONFIG_LEN		40
+
+static struct kgdb_io		kgdboc_io_ops;
+
+/* -1 = init not run yet, 0 = unconfigured, 1 = configured. */
+static int configured		= -1;
+
+static char config[MAX_CONFIG_LEN];
+static struct kparam_string kps = {
+	.string			= config,
+	.maxlen			= MAX_CONFIG_LEN,
+};
+
+static struct tty_driver	*kgdb_tty_driver;
+static int			kgdb_tty_line;
+
+static int kgdboc_option_setup(char *opt)
+{
+	if (strlen(opt) > MAX_CONFIG_LEN) {
+		printk(KERN_ERR "kgdboc: config string too long\n");
+		return -ENOSPC;
+	}
+	strcpy(config, opt);
+
+	return 0;
+}
+
+__setup("kgdboc=", kgdboc_option_setup);
+
+static int configure_kgdboc(void)
+{
+	struct tty_driver *p;
+	int tty_line = 0;
+	int err;
+
+	err = kgdboc_option_setup(config);
+	if (err || !strlen(config) || isspace(config[0]))
+		goto noconfig;
+
+	err = -ENODEV;
+
+	p = tty_find_polling_driver(config, &tty_line);
+	if (!p)
+		goto noconfig;
+
+	kgdb_tty_driver = p;
+	kgdb_tty_line = tty_line;
+
+	err = kgdb_register_io_module(&kgdboc_io_ops);
+	if (err)
+		goto noconfig;
+
+	configured = 1;
+
+	return 0;
+
+noconfig:
+	config[0] = 0;
+	configured = 0;
+
+	return err;
+}
+
+static int __init init_kgdboc(void)
+{
+	/* Already configured? */
+	if (configured == 1)
+		return 0;
+
+	return configure_kgdboc();
+}
+
+static void cleanup_kgdboc(void)
+{
+	if (configured == 1)
+		kgdb_unregister_io_module(&kgdboc_io_ops);
+}
+
+static int kgdboc_get_char(void)
+{
+	return kgdb_tty_driver->poll_get_char(kgdb_tty_driver, kgdb_tty_line);
+}
+
+static void kgdboc_put_char(u8 chr)
+{
+	kgdb_tty_driver->poll_put_char(kgdb_tty_driver, kgdb_tty_line, chr);
+}
+
+static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp)
+{
+	int len = strlen(kmessage);
+
+	if (len >= MAX_CONFIG_LEN) {
+		printk(KERN_ERR "kgdboc: config string too long\n");
+		return -ENOSPC;
+	}
+
+	/* Only copy in the string if the init function has not run yet */
+	if (configured < 0) {
+		strcpy(config, kmessage);
+		return 0;
+	}
+
+	if (kgdb_connected) {
+		printk(KERN_ERR
+		       "kgdboc: Cannot reconfigure while KGDB is connected.\n");
+
+		return -EBUSY;
+	}
+
+	strcpy(config, kmessage);
+	/* Chop out \n char as a result of echo */
+	if (config[len - 1] == '\n')
+		config[len - 1] = '\0';
+
+	if (configured == 1)
+		cleanup_kgdboc();
+
+	/* Go and configure with the new params. */
+	return configure_kgdboc();
+}
+
+static void kgdboc_pre_exp_handler(void)
+{
+	/* Increment the module count when the debugger is active */
+	if (!kgdb_connected)
+		try_module_get(THIS_MODULE);
+}
+
+static void kgdboc_post_exp_handler(void)
+{
+	/* decrement the module count when the debugger detaches */
+	if (!kgdb_connected)
+		module_put(THIS_MODULE);
+}
+
+static struct kgdb_io kgdboc_io_ops = {
+	.name			= "kgdboc",
+	.read_char		= kgdboc_get_char,
+	.write_char		= kgdboc_put_char,
+	.pre_exception		= kgdboc_pre_exp_handler,
+	.post_exception		= kgdboc_post_exp_handler,
+};
+
+module_init(init_kgdboc);
+module_exit(cleanup_kgdboc);
+module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644);
+MODULE_PARM_DESC(kgdboc, "<serial_device>[,baud]");
+MODULE_DESCRIPTION("KGDB Console TTY Driver");
+MODULE_LICENSE("GPL");

drivers/serial/serial_core.c

@@ -1771,7 +1771,7 @@ static int uart_read_proc(char *page, char **start, off_t off,
 }
 #endif
 
-#ifdef CONFIG_SERIAL_CORE_CONSOLE
+#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
 /*
  *	uart_console_write - write a console message to a serial port
  *	@port: the port to write the message
@@ -1827,7 +1827,7 @@ uart_get_console(struct uart_port *ports, int nr, struct console *co)
  *	options.  The format of the string is <baud><parity><bits><flow>,
  *	eg: 115200n8r
  */
-void __init
+void
 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
 {
 	char *s = options;
@@ -1842,6 +1842,7 @@ uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
 	if (*s)
 		*flow = *s;
 }
+EXPORT_SYMBOL_GPL(uart_parse_options);
 
 struct baud_rates {
 	unsigned int rate;
@@ -1872,7 +1873,7 @@ static const struct baud_rates baud_rates[] = {
  *	@bits: number of data bits
  *	@flow: flow control character - 'r' (rts)
  */
-int __init
+int
 uart_set_options(struct uart_port *port, struct console *co,
 		 int baud, int parity, int bits, int flow)
 {
@@ -1924,10 +1925,16 @@ uart_set_options(struct uart_port *port, struct console *co,
 	port->mctrl |= TIOCM_DTR;
 
 	port->ops->set_termios(port, &termios, &dummy);
-	co->cflag = termios.c_cflag;
+	/*
+	 * Allow the setting of the UART parameters with a NULL console
+	 * too:
+	 */
+	if (co)
+		co->cflag = termios.c_cflag;
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(uart_set_options);
 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
 
 static void uart_change_pm(struct uart_state *state, int pm_state)
@@ -2182,6 +2189,60 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 	}
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+
+static int uart_poll_init(struct tty_driver *driver, int line, char *options)
+{
+	struct uart_driver *drv = driver->driver_state;
+	struct uart_state *state = drv->state + line;
+	struct uart_port *port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (!state || !state->port)
+		return -1;
+
+	port = state->port;
+	if (!(port->ops->poll_get_char && port->ops->poll_put_char))
+		return -1;
+
+	if (options) {
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+		return uart_set_options(port, NULL, baud, parity, bits, flow);
+	}
+
+	return 0;
+}
+
+static int uart_poll_get_char(struct tty_driver *driver, int line)
+{
+	struct uart_driver *drv = driver->driver_state;
+	struct uart_state *state = drv->state + line;
+	struct uart_port *port;
+
+	if (!state || !state->port)
+		return -1;
+
+	port = state->port;
+	return port->ops->poll_get_char(port);
+}
+
+static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
+{
+	struct uart_driver *drv = driver->driver_state;
+	struct uart_state *state = drv->state + line;
+	struct uart_port *port;
+
+	if (!state || !state->port)
+		return;
+
+	port = state->port;
+	port->ops->poll_put_char(port, ch);
+}
+#endif
+
 static const struct tty_operations uart_ops = {
 	.open		= uart_open,
 	.close		= uart_close,
@@ -2206,6 +2267,11 @@ static const struct tty_operations uart_ops = {
 #endif
 	.tiocmget	= uart_tiocmget,
 	.tiocmset	= uart_tiocmset,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_init	= uart_poll_init,
+	.poll_get_char	= uart_poll_get_char,
+	.poll_put_char	= uart_poll_put_char,
+#endif
 };
 
 /**

include/asm-x86/kdebug.h

@@ -20,6 +20,7 @@ enum die_val {
 	DIE_CALL,
 	DIE_NMI_IPI,
 	DIE_PAGE_FAULT,
+	DIE_NMIUNKNOWN,
 };
 
 extern void printk_address(unsigned long address, int reliable);

include/asm-x86/kgdb.h

+#ifndef _ASM_KGDB_H_
+#define _ASM_KGDB_H_
+
+/*
+ * Copyright (C) 2001-2004 Amit S. Kale
+ * Copyright (C) 2008 Wind River Systems, Inc.
+ */
+
+/*
+ * BUFMAX defines the maximum number of characters in inbound/outbound
+ * buffers at least NUMREGBYTES*2 are needed for register packets
+ * Longer buffer is needed to list all threads
+ */
+#define BUFMAX			1024
+
+/*
+ *  Note that this register image is in a different order than
+ *  the register image that Linux produces at interrupt time.
+ *
+ *  Linux's register image is defined by struct pt_regs in ptrace.h.
+ *  Just why GDB uses a different order is a historical mystery.
+ */
+#ifdef CONFIG_X86_32
+enum regnames {
+	GDB_AX,			/* 0 */
+	GDB_CX,			/* 1 */
+	GDB_DX,			/* 2 */
+	GDB_BX,			/* 3 */
+	GDB_SP,			/* 4 */
+	GDB_BP,			/* 5 */
+	GDB_SI,			/* 6 */
+	GDB_DI,			/* 7 */
+	GDB_PC,			/* 8 also known as eip */
+	GDB_PS,			/* 9 also known as eflags */
+	GDB_CS,			/* 10 */
+	GDB_SS,			/* 11 */
+	GDB_DS,			/* 12 */
+	GDB_ES,			/* 13 */
+	GDB_FS,			/* 14 */
+	GDB_GS,			/* 15 */
+};
+#else /* ! CONFIG_X86_32 */
+enum regnames {
+	GDB_AX,			/* 0 */
+	GDB_DX,			/* 1 */
+	GDB_CX,			/* 2 */
+	GDB_BX,			/* 3 */
+	GDB_SI,			/* 4 */
+	GDB_DI,			/* 5 */
+	GDB_BP,			/* 6 */
+	GDB_SP,			/* 7 */
+	GDB_R8,			/* 8 */
+	GDB_R9,			/* 9 */
+	GDB_R10,		/* 10 */
+	GDB_R11,		/* 11 */
+	GDB_R12,		/* 12 */
+	GDB_R13,		/* 13 */
+	GDB_R14,		/* 14 */
+	GDB_R15,		/* 15 */
+	GDB_PC,			/* 16 */
+	GDB_PS,			/* 17 */
+};
+#endif /* CONFIG_X86_32 */
+
+/*
+ * Number of bytes of registers:
+ */
+#ifdef CONFIG_X86_32
+# define NUMREGBYTES		64
+#else
+# define NUMREGBYTES		((GDB_PS+1)*8)
+#endif
+
+static inline void arch_kgdb_breakpoint(void)
+{
+	asm("   int $3");
+}
+#define BREAK_INSTR_SIZE	1
+#define CACHE_FLUSH_IS_SAFE	1
+
+#endif				/* _ASM_KGDB_H_ */

include/linux/clocksource.h

@@ -216,6 +216,7 @@ static inline void clocksource_calculate_interval(struct clocksource *c,
 /* used to install a new clocksource */
 extern int clocksource_register(struct clocksource*);
 extern void clocksource_unregister(struct clocksource*);
+extern void clocksource_touch_watchdog(void);
 extern struct clocksource* clocksource_get_next(void);
 extern void clocksource_change_rating(struct clocksource *cs, int rating);
 extern void clocksource_resume(void);

include/linux/kgdb.h

+/*
+ * This provides the callbacks and functions that KGDB needs to share between
+ * the core, I/O and arch-specific portions.
+ *
+ * Author: Amit Kale <amitkale@linsyssoft.com> and
+ *         Tom Rini <trini@kernel.crashing.org>
+ *
+ * 2001-2004 (c) Amit S. Kale and 2003-2005 (c) MontaVista Software, Inc.
+ * 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.
+ */
+#ifndef _KGDB_H_
+#define _KGDB_H_
+
+#include <linux/serial_8250.h>
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+#include <asm/atomic.h>
+#include <asm/kgdb.h>
+
+struct pt_regs;
+
+/**
+ *	kgdb_skipexception - (optional) exit kgdb_handle_exception early
+ *	@exception: Exception vector number
+ *	@regs: Current &struct pt_regs.
+ *
+ *	On some architectures it is required to skip a breakpoint
+ *	exception when it occurs after a breakpoint has been removed.
+ *	This can be implemented in the architecture specific portion of
+ *	for kgdb.
+ */
+extern int kgdb_skipexception(int exception, struct pt_regs *regs);
+
+/**
+ *	kgdb_post_primary_code - (optional) Save error vector/code numbers.
+ *	@regs: Original pt_regs.
+ *	@e_vector: Original error vector.
+ *	@err_code: Original error code.
+ *
+ *	This is usually needed on architectures which support SMP and
+ *	KGDB.  This function is called after all the secondary cpus have
+ *	been put to a know spin state and the primary CPU has control over
+ *	KGDB.
+ */
+extern void kgdb_post_primary_code(struct pt_regs *regs, int e_vector,
+				  int err_code);
+
+/**
+ *	kgdb_disable_hw_debug - (optional) Disable hardware debugging hook
+ *	@regs: Current &struct pt_regs.
+ *
+ *	This function will be called if the particular architecture must
+ *	disable hardware debugging while it is processing gdb packets or
+ *	handling exception.
+ */
+extern void kgdb_disable_hw_debug(struct pt_regs *regs);
+
+struct tasklet_struct;
+struct task_struct;
+struct uart_port;
+
+/**
+ *	kgdb_breakpoint - compiled in breakpoint
+ *
+ *	This will be impelmented a static inline per architecture.  This
+ *	function is called by the kgdb core to execute an architecture
+ *	specific trap to cause kgdb to enter the exception processing.
+ *
+ */
+void kgdb_breakpoint(void);
+
+extern int kgdb_connected;
+
+extern atomic_t			kgdb_setting_breakpoint;
+extern atomic_t			kgdb_cpu_doing_single_step;
+
+extern struct task_struct	*kgdb_usethread;
+extern struct task_struct	*kgdb_contthread;
+
+enum kgdb_bptype {
+	BP_BREAKPOINT = 0,
+	BP_HARDWARE_BREAKPOINT,
+	BP_WRITE_WATCHPOINT,
+	BP_READ_WATCHPOINT,
+	BP_ACCESS_WATCHPOINT
+};
+
+enum kgdb_bpstate {
+	BP_UNDEFINED = 0,
+	BP_REMOVED,
+	BP_SET,
+	BP_ACTIVE
+};
+
+struct kgdb_bkpt {
+	unsigned long		bpt_addr;
+	unsigned char		saved_instr[BREAK_INSTR_SIZE];
+	enum kgdb_bptype	type;
+	enum kgdb_bpstate	state;
+};
+
+#ifndef KGDB_MAX_BREAKPOINTS
+# define KGDB_MAX_BREAKPOINTS	1000
+#endif
+
+#define KGDB_HW_BREAKPOINT	1
+
+/*
+ * Functions each KGDB-supporting architecture must provide:
+ */
+
+/**
+ *	kgdb_arch_init - Perform any architecture specific initalization.
+ *
+ *	This function will handle the initalization of any architecture
+ *	specific callbacks.
+ */
+extern int kgdb_arch_init(void);
+
+/**
+ *	kgdb_arch_exit - Perform any architecture specific uninitalization.
+ *
+ *	This function will handle the uninitalization of any architecture
+ *	specific callbacks, for dynamic registration and unregistration.
+ */
+extern void kgdb_arch_exit(void);
+
+/**
+ *	pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
+ *	@gdb_regs: A pointer to hold the registers in the order GDB wants.
+ *	@regs: The &struct pt_regs of the current process.
+ *
+ *	Convert the pt_regs in @regs into the format for registers that
+ *	GDB expects, stored in @gdb_regs.
+ */
+extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs);
+
+/**
+ *	sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
+ *	@gdb_regs: A pointer to hold the registers in the order GDB wants.
+ *	@p: The &struct task_struct of the desired process.
+ *
+ *	Convert the register values of the sleeping process in @p to
+ *	the format that GDB expects.
+ *	This function is called when kgdb does not have access to the
+ *	&struct pt_regs and therefore it should fill the gdb registers
+ *	@gdb_regs with what has	been saved in &struct thread_struct
+ *	thread field during switch_to.
+ */
+extern void
+sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p);
+
+/**
+ *	gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
+ *	@gdb_regs: A pointer to hold the registers we've received from GDB.
+ *	@regs: A pointer to a &struct pt_regs to hold these values in.
+ *
+ *	Convert the GDB regs in @gdb_regs into the pt_regs, and store them
+ *	in @regs.
+ */
+extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs);
+
+/**
+ *	kgdb_arch_handle_exception - Handle architecture specific GDB packets.
+ *	@vector: The error vector of the exception that happened.
+ *	@signo: The signal number of the exception that happened.
+ *	@err_code: The error code of the exception that happened.
+ *	@remcom_in_buffer: The buffer of the packet we have read.
+ *	@remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
+ *	@regs: The &struct pt_regs of the current process.
+ *
+ *	This function MUST handle the 'c' and 's' command packets,
+ *	as well packets to set / remove a hardware breakpoint, if used.
+ *	If there are additional packets which the hardware needs to handle,
+ *	they are handled here.  The code should return -1 if it wants to
+ *	process more packets, and a %0 or %1 if it wants to exit from the
+ *	kgdb callback.
+ */
+extern int
+kgdb_arch_handle_exception(int vector, int signo, int err_code,
+			   char *remcom_in_buffer,
+			   char *remcom_out_buffer,
+			   struct pt_regs *regs);
+
+/**
+ *	kgdb_roundup_cpus - Get other CPUs into a holding pattern
+ *	@flags: Current IRQ state
+ *
+ *	On SMP systems, we need to get the attention of the other CPUs
+ *	and get them be in a known state.  This should do what is needed
+ *	to get the other CPUs to call kgdb_wait(). Note that on some arches,
+ *	the NMI approach is not used for rounding up all the CPUs. For example,
+ *	in case of MIPS, smp_call_function() is used to roundup CPUs. In
+ *	this case, we have to make sure that interrupts are enabled before
+ *	calling smp_call_function(). The argument to this function is
+ *	the flags that will be used when restoring the interrupts. There is
+ *	local_irq_save() call before kgdb_roundup_cpus().
+ *
+ *	On non-SMP systems, this is not called.
+ */
+extern void kgdb_roundup_cpus(unsigned long flags);
+
+/* Optional functions. */
+extern int kgdb_validate_break_address(unsigned long addr);
+extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr);
+extern int kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle);
+
+/**
+ * struct kgdb_arch - Describe architecture specific values.
+ * @gdb_bpt_instr: The instruction to trigger a breakpoint.
+ * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT.
+ * @set_breakpoint: Allow an architecture to specify how to set a software
+ * breakpoint.
+ * @remove_breakpoint: Allow an architecture to specify how to remove a
+ * software breakpoint.
+ * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware
+ * breakpoint.
+ * @remove_hw_breakpoint: Allow an architecture to specify how to remove a
+ * hardware breakpoint.
+ * @remove_all_hw_break: Allow an architecture to specify how to remove all
+ * hardware breakpoints.
+ * @correct_hw_break: Allow an architecture to specify how to correct the
+ * hardware debug registers.
+ */
+struct kgdb_arch {
+	unsigned char		gdb_bpt_instr[BREAK_INSTR_SIZE];
+	unsigned long		flags;
+
+	int	(*set_breakpoint)(unsigned long, char *);
+	int	(*remove_breakpoint)(unsigned long, char *);
+	int	(*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
+	int	(*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
+	void	(*remove_all_hw_break)(void);
+	void	(*correct_hw_break)(void);
+};
+
+/**
+ * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB.
+ * @name: Name of the I/O driver.
+ * @read_char: Pointer to a function that will return one char.
+ * @write_char: Pointer to a function that will write one char.
+ * @flush: Pointer to a function that will flush any pending writes.
+ * @init: Pointer to a function that will initialize the device.
+ * @pre_exception: Pointer to a function that will do any prep work for
+ * the I/O driver.
+ * @post_exception: Pointer to a function that will do any cleanup work
+ * for the I/O driver.
+ */
+struct kgdb_io {
+	const char		*name;
+	int			(*read_char) (void);
+	void			(*write_char) (u8);
+	void			(*flush) (void);
+	int			(*init) (void);
+	void			(*pre_exception) (void);
+	void			(*post_exception) (void);
+};
+
+extern struct kgdb_arch		arch_kgdb_ops;
+
+extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
+extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
+
+extern int kgdb_hex2long(char **ptr, long *long_val);
+extern int kgdb_mem2hex(char *mem, char *buf, int count);
+extern int kgdb_hex2mem(char *buf, char *mem, int count);
+
+extern int kgdb_isremovedbreak(unsigned long addr);
+
+extern int
+kgdb_handle_exception(int ex_vector, int signo, int err_code,
+		      struct pt_regs *regs);
+extern int kgdb_nmicallback(int cpu, void *regs);
+
+extern int			kgdb_single_step;
+extern atomic_t			kgdb_active;
+
+#endif /* _KGDB_H_ */

include/linux/serial_core.h

@@ -213,6 +213,10 @@ struct uart_ops {
 	void		(*config_port)(struct uart_port *, int);
 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
+#ifdef CONFIG_CONSOLE_POLL
+	void	(*poll_put_char)(struct uart_port *, unsigned char);
+	int		(*poll_get_char)(struct uart_port *);
+#endif
 };
 
 #define UART_CONFIG_TYPE	(1 << 0)

include/linux/tty_driver.h

@@ -125,6 +125,7 @@
 #include <linux/cdev.h>
 
 struct tty_struct;
+struct tty_driver;
 
 struct tty_operations {
 	int  (*open)(struct tty_struct * tty, struct file * filp);
@@ -157,6 +158,11 @@ struct tty_operations {
 	int (*tiocmget)(struct tty_struct *tty, struct file *file);
 	int (*tiocmset)(struct tty_struct *tty, struct file *file,
 			unsigned int set, unsigned int clear);
+#ifdef CONFIG_CONSOLE_POLL
+	int (*poll_init)(struct tty_driver *driver, int line, char *options);
+	int (*poll_get_char)(struct tty_driver *driver, int line);
+	void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
+#endif
 };
 
 struct tty_driver {
@@ -220,6 +226,11 @@ struct tty_driver {
 	int (*tiocmget)(struct tty_struct *tty, struct file *file);
 	int (*tiocmset)(struct tty_struct *tty, struct file *file,
 			unsigned int set, unsigned int clear);
+#ifdef CONFIG_CONSOLE_POLL
+	int (*poll_init)(struct tty_driver *driver, int line, char *options);
+	int (*poll_get_char)(struct tty_driver *driver, int line);
+	void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
+#endif
 
 	struct list_head tty_drivers;
 };
@@ -230,6 +241,7 @@ struct tty_driver *alloc_tty_driver(int lines);
 void put_tty_driver(struct tty_driver *driver);
 void tty_set_operations(struct tty_driver *driver,
 			const struct tty_operations *op);
+extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
 
 /* tty driver magic number */
 #define TTY_DRIVER_MAGIC		0x5402

include/linux/uaccess.h

@@ -84,4 +84,26 @@ static inline unsigned long __copy_from_user_nocache(void *to,
 		ret;					\
 	})
 
+/*
+ * probe_kernel_read(): safely attempt to read from a location
+ * @dst: pointer to the buffer that shall take the data
+ * @src: address to read from
+ * @size: size of the data chunk
+ *
+ * Safely read from address @src to the buffer at @dst.  If a kernel fault
+ * happens, handle that and return -EFAULT.
+ */
+extern long probe_kernel_read(void *dst, void *src, size_t size);
+
+/*
+ * probe_kernel_write(): safely attempt to write to a location
+ * @dst: address to write to
+ * @src: pointer to the data that shall be written
+ * @size: size of the data chunk
+ *
+ * Safely write to address @dst from the buffer at @src.  If a kernel fault
+ * happens, handle that and return -EFAULT.
+ */
+extern long probe_kernel_write(void *dst, void *src, size_t size);
+
 #endif		/* __LINUX_UACCESS_H__ */

kernel/Makefile

@@ -53,6 +53,7 @@ obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
 obj-$(CONFIG_AUDITSYSCALL) += auditsc.o
 obj-$(CONFIG_AUDIT_TREE) += audit_tree.o
 obj-$(CONFIG_KPROBES) += kprobes.o
+obj-$(CONFIG_KGDB) += kgdb.o
 obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o
 obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
 obj-$(CONFIG_SECCOMP) += seccomp.o

kernel/time/clocksource.c

@@ -221,6 +221,18 @@ void clocksource_resume(void)
 	spin_unlock_irqrestore(&clocksource_lock, flags);
 }
 
+/**
+ * clocksource_touch_watchdog - Update watchdog
+ *
+ * Update the watchdog after exception contexts such as kgdb so as not
+ * to incorrectly trip the watchdog.
+ *
+ */
+void clocksource_touch_watchdog(void)
+{
+	clocksource_resume_watchdog();
+}
+
 /**
  * clocksource_get_next - Returns the selected clocksource
  *

lib/Kconfig.debug

@@ -612,3 +612,5 @@ config PROVIDE_OHCI1394_DMA_INIT
 	  See Documentation/debugging-via-ohci1394.txt for more information.
 
 source "samples/Kconfig"
+
+source "lib/Kconfig.kgdb"

lib/Kconfig.kgdb

+
+menuconfig KGDB
+	bool "KGDB: kernel debugging with remote gdb"
+	select FRAME_POINTER
+	depends on HAVE_ARCH_KGDB
+	depends on DEBUG_KERNEL && EXPERIMENTAL
+	help
+	  If you say Y here, it will be possible to remotely debug the
+	  kernel using gdb.  Documentation of kernel debugger is available
+	  at http://kgdb.sourceforge.net as well as in DocBook form
+	  in Documentation/DocBook/.  If unsure, say N.
+
+config HAVE_ARCH_KGDB_SHADOW_INFO
+	bool
+
+config HAVE_ARCH_KGDB
+	bool
+
+config KGDB_SERIAL_CONSOLE
+	tristate "KGDB: use kgdb over the serial console"
+	depends on KGDB
+	select CONSOLE_POLL
+	select MAGIC_SYSRQ
+	default y
+	help
+	  Share a serial console with kgdb. Sysrq-g must be used
+	  to break in initially.
+
+config KGDB_TESTS
+	bool "KGDB: internal test suite"
+	depends on KGDB
+	default n
+	help
+	  This is a kgdb I/O module specifically designed to test
+	  kgdb's internal functions.  This kgdb I/O module is
+	  intended to for the development of new kgdb stubs
+	  as well as regression testing the kgdb internals.
+	  See the drivers/misc/kgdbts.c for the details about
+	  the tests.  The most basic of this I/O module is to boot
+	  a kernel boot arguments "kgdbwait kgdbts=V1F100"
+
+config KGDB_TESTS_ON_BOOT
+	bool "KGDB: Run tests on boot"
+	depends on KGDB_TESTS
+	default n
+	help
+	  Run the kgdb tests on boot up automatically without the need
+	  to pass in a kernel parameter
+
+config KGDB_TESTS_BOOT_STRING
+	string "KGDB: which internal kgdb tests to run"
+	depends on KGDB_TESTS_ON_BOOT
+	default "V1F100"
+	help
+	  This is the command string to send the kgdb test suite on
+	  boot.  See the drivers/misc/kgdbts.c for detailed
+	  information about other strings you could use beyond the
+	  default of V1F100.

mm/Makefile

@@ -8,7 +8,7 @@ mmu-$(CONFIG_MMU)	:= fremap.o highmem.o madvise.o memory.o mincore.o \
 			   vmalloc.o
 
 obj-y			:= bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \
-			   page_alloc.o page-writeback.o pdflush.o \
+			   maccess.o page_alloc.o page-writeback.o pdflush.o \
 			   readahead.o swap.o truncate.o vmscan.o \
 			   prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \
 			   page_isolation.o $(mmu-y)

mm/maccess.c

+/*
+ * Access kernel memory without faulting.
+ */
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+
+/**
+ * probe_kernel_read(): safely attempt to read from a location
+ * @dst: pointer to the buffer that shall take the data
+ * @src: address to read from
+ * @size: size of the data chunk
+ *
+ * Safely read from address @src to the buffer at @dst.  If a kernel fault
+ * happens, handle that and return -EFAULT.
+ */
+long probe_kernel_read(void *dst, void *src, size_t size)
+{
+	long ret;
+	mm_segment_t old_fs = get_fs();
+
+	set_fs(KERNEL_DS);
+	pagefault_disable();
+	ret = __copy_from_user_inatomic(dst,
+			(__force const void __user *)src, size);
+	pagefault_enable();
+	set_fs(old_fs);
+
+	return ret ? -EFAULT : 0;
+}
+EXPORT_SYMBOL_GPL(probe_kernel_read);
+
+/**
+ * probe_kernel_write(): safely attempt to write to a location
+ * @dst: address to write to
+ * @src: pointer to the data that shall be written
+ * @size: size of the data chunk
+ *
+ * Safely write to address @dst from the buffer at @src.  If a kernel fault
+ * happens, handle that and return -EFAULT.
+ */
+long probe_kernel_write(void *dst, void *src, size_t size)
+{
+	long ret;
+	mm_segment_t old_fs = get_fs();
+
+	set_fs(KERNEL_DS);
+	pagefault_disable();
+	ret = __copy_to_user_inatomic((__force void __user *)dst, src, size);
+	pagefault_enable();
+	set_fs(old_fs);
+
+	return ret ? -EFAULT : 0;
+}
+EXPORT_SYMBOL_GPL(probe_kernel_write);