kgdb-lite for 2.6.2

Hi!

kgdb-lite is version of kgdb with thread support and console-over-kgdb
support removed, to reduce impact on generic code.

This is only arch-independend part. Does it look like it could be
included in the -mm?
								Pavel


--- clean.2.5/Makefile	2004-02-05 01:53:53.000000000 +0100
+++ linux-mm/Makefile	2004-02-16 23:09:06.000000000 +0100
@@ -440,6 +440,8 @@
 
 ifndef CONFIG_FRAME_POINTER
 CFLAGS		+= -fomit-frame-pointer
+else
+CFLAGS		+= -fno-omit-frame-pointer
 endif
 
 ifdef CONFIG_DEBUG_INFO
--- clean.2.5/drivers/serial/8250.c	2004-01-09 20:24:22.000000000 +0100
+++ linux-mm/drivers/serial/8250.c	2004-02-16 23:09:06.000000000 +0100
@@ -1198,12 +1198,17 @@
 	spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
+static int released_irq = -1;
+
 static int serial8250_startup(struct uart_port *port)
 {
 	struct uart_8250_port *up = (struct uart_8250_port *)port;
 	unsigned long flags;
 	int retval;
 
+	if (up->port.irq == released_irq)
+		return -EBUSY;
+
 	up->capabilities = uart_config[up->port.type].flags;
 
 	if (up->port.type == PORT_16C950) {
@@ -1869,6 +1874,10 @@
 	for (i = 0; i < UART_NR; i++) {
 		struct uart_8250_port *up = &serial8250_ports[i];
 
+		if (up->port.irq == released_irq) {
+			continue;
+		}
+
 		up->port.line = i;
 		up->port.ops = &serial8250_pops;
 		init_timer(&up->timer);
@@ -2138,6 +2147,36 @@
 	uart_resume_port(&serial8250_reg, &serial8250_ports[line].port);
 }
 
+/*
+ * Find all the ports using the given irq and shut them down.
+ * Result should be that the irq will be released.
+ * At most one irq can be released this way.
+ * Once an irq is released, any attempts to initialize a port with that irq
+ * will fail with EBUSY.
+ */
+
+int serial8250_release_irq(int irq)
+{
+        struct uart_8250_port *up;
+	int ttyS;
+
+	if (released_irq != -1) {
+		return -EBUSY;
+	}
+	released_irq = irq;
+	for (ttyS = 0; ttyS < UART_NR; ttyS++){
+		up =  &serial8250_ports[ttyS];
+		if (up->port.irq == irq && (irq_lists + irq)->head) {
+#ifdef CONFIG_DEBUG_SPINLOCK   /* ugly business... */
+			if(up->port.lock.magic != SPINLOCK_MAGIC)
+				spin_lock_init(&up->port.lock);
+#endif
+			serial8250_shutdown(&up->port);
+		}
+        }
+	return 0;
+}
+
 static int __init serial8250_init(void)
 {
 	int ret, i;
--- clean.2.5/drivers/serial/Kconfig	2004-02-05 01:54:11.000000000 +0100
+++ linux-mm/drivers/serial/Kconfig	2004-02-16 23:09:06.000000000 +0100
@@ -6,6 +6,13 @@
 
 menu "Serial drivers"
 
+config KGDB_8250
+	bool "KGDB: On generic serial port (8250)"
+	depends on KGDB
+	help
+	  Uses generic serial port (8250) for kgdb. This is independent of the
+	  option 9250/16550 and compatible serial port.
+
 #
 # The new 8250/16550 serial drivers
 config SERIAL_8250
--- clean.2.5/drivers/serial/Makefile	2003-09-28 22:06:15.000000000 +0200
+++ linux-mm/drivers/serial/Makefile	2004-02-16 23:09:06.000000000 +0100
@@ -32,3 +32,5 @@
 obj-$(CONFIG_V850E_UART) += v850e_uart.o
 obj-$(CONFIG_SERIAL98) += serial98.o
 obj-$(CONFIG_SERIAL_PMACZILOG) += pmac_zilog.o
+
+obj-$(CONFIG_KGDB_8250) += kgdb_8250.o
--- clean.2.5/drivers/serial/kgdb_8250.c	2004-02-17 11:37:58.000000000 +0100
+++ linux-mm/drivers/serial/kgdb_8250.c	2004-02-16 23:32:39.000000000 +0100
@@ -0,0 +1,396 @@
+/*
+ * 8250 interface for kgdb.
+ *
+ * Restructured for making kgdb capable of handling different types of serial
+ * interfaces, by Amit Kale (amitkale@emsyssoft.com)
+ *
+ * Written (hacked together) by David Grothe (dave@gcom.com)
+ *
+ * Modified by Scott Foehner (sfoehner@engr.sgi.com) to allow connect
+ * on boot-up
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+#include <linux/serialP.h>
+#include <linux/config.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/termios.h>
+#include <linux/kgdb.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/segment.h>
+#include <asm/bitops.h>
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/atomic.h>
+
+#define	GDB_BUF_SIZE	512		/* power of 2, please */
+
+static char	kgdb8250_buf[GDB_BUF_SIZE];
+static int	kgdb8250_buf_in_inx;
+static atomic_t	kgdb8250_buf_in_cnt;
+static int	kgdb8250_buf_out_inx;
+
+
+static int kgdb8250_got_dollar = -3, kgdb8250_got_H = -3,
+	kgdb8250_interrupt_iteration = 0;
+
+/* We only allow for 4 ports to be registered.  We default to standard
+ * PC values. */
+static struct uart_port rs_table[4] = {
+	{ .line = 0x3f8, .irq = 4 },
+	{ .line = 0x2f8, .irq = 3 },
+	{ .line = 0x3e8, .irq = 4 },
+	{ .line = 0x2e8, .irq = 3 },
+};
+static void (*serial_outb)(unsigned char, unsigned long);
+static unsigned long (*serial_inb)(unsigned long);
+
+int serial8250_release_irq(int irq);
+
+int kgdb8250_irq;
+unsigned long kgdb8250_port;
+
+int kgdb8250_baud = 115200;
+int kgdb8250_ttyS;
+
+static unsigned long direct_inb(unsigned long addr)
+{
+	return readb(addr);
+}
+
+static void direct_outb(unsigned char val, unsigned long addr)
+{
+	writeb(val, addr);
+}
+
+static unsigned long io_inb(unsigned long port)
+{
+	return inb(port);
+}
+
+static void io_outb(unsigned char val, unsigned long port)
+{
+	outb(val, port);
+}
+
+/*
+ * Get a byte from the hardware data buffer and return it
+ * Get a char if available, return -EAGAIN if nothing available.
+ */
+static int read_data_bfr(void)
+{
+	if (serial_inb(kgdb8250_port + UART_LSR) & UART_LSR_DR)
+		return(serial_inb(kgdb8250_port + UART_RX));
+
+	return -EAGAIN;
+}
+
+/*
+ * Empty the receive buffer first, then look at the interface hardware.
+ * It waits for a character from the serial interface and then returns it.
+ */
+static int kgdb8250_read_char(void)
+{
+	int retchar;
+	if (atomic_read(&kgdb8250_buf_in_cnt) != 0)
+	{
+		/* intr routine has q'd chars read them from buffer */
+		int		chr;
+
+		chr = kgdb8250_buf[kgdb8250_buf_out_inx++];
+		kgdb8250_buf_out_inx &= (GDB_BUF_SIZE - 1);
+		atomic_dec(&kgdb8250_buf_in_cnt);
+		return chr;
+	}
+	do {
+		/* read from hardware */
+		retchar = read_data_bfr();
+	} while (retchar < 0);
+	return retchar;
+} 
+
+/*
+ * Wait until the interface can accept a char, then write it.
+ */
+static void kgdb8250_write_char(int chr)
+{
+    while (!(serial_inb(kgdb8250_port + UART_LSR) & UART_LSR_THRE))
+	    /* Do nothing */;
+
+    serial_outb(chr, kgdb8250_port+UART_TX);
+
+}
+
+/*
+ * This is the receiver interrupt routine for the GDB stub.
+ * It will receive a limited number of characters of input
+ * from the gdb  host machine and save them up in a buffer.
+ *
+ * When kgdb8250_read_char() is called it
+ * draws characters out of the buffer until it is empty and
+ * then reads directly from the serial port.
+ *
+ * We do not attempt to write chars from the interrupt routine
+ * since the stubs do all of that via kgdb8250_write_char() which
+ * writes one byte after waiting for the interface to become
+ * ready.
+ *
+ * The debug stubs like to run with interrupts disabled since,
+ * after all, they run as a consequence of a breakpoint in
+ * the kernel.
+ *
+ * Perhaps someone who knows more about the tty driver than I
+ * care to learn can make this work for any low level serial
+ * driver.
+ */
+static irqreturn_t kgdb8250_interrupt(int irq, void *dev_id,
+		struct pt_regs * regs)
+{
+	int	chr;
+	int	iir;
+
+	do
+	{
+		chr = read_data_bfr();
+		iir = serial_inb(kgdb8250_port + UART_IIR);
+		if (chr < 0) continue ;
+
+		/* Check whether gdb sent interrupt */
+		if (chr == 3)                  
+		{
+			breakpoint();
+			continue ;
+		}
+
+		if(atomic_read(&kgdb_killed_or_detached)) {
+			if (chr == '$') 
+				kgdb8250_got_dollar = kgdb8250_interrupt_iteration;
+			if (kgdb8250_interrupt_iteration == kgdb8250_got_dollar + 1 &&
+			    chr == 'H') 
+				kgdb8250_got_H  = kgdb8250_interrupt_iteration;
+			else if (kgdb8250_interrupt_iteration == kgdb8250_got_H + 1 && 
+				chr == 'c') {
+				kgdb8250_buf[kgdb8250_buf_in_inx++] = chr;
+				atomic_inc(&kgdb8250_buf_in_cnt);
+				atomic_set(&kgdb_might_be_resumed, 1);
+				wmb();
+				breakpoint();
+				atomic_set(&kgdb_might_be_resumed, 0);
+				kgdb8250_interrupt_iteration = 0;
+				kgdb8250_got_dollar = -3;
+				kgdb8250_got_H = -3;
+				continue;
+			}
+		}
+
+		if (atomic_read(&kgdb8250_buf_in_cnt) >= GDB_BUF_SIZE)
+		{
+			/* buffer overflow, clear it */
+			kgdb8250_buf_in_inx = 0 ;
+			atomic_set(&kgdb8250_buf_in_cnt, 0) ;
+			kgdb8250_buf_out_inx = 0 ;
+			break ;
+		}
+
+		kgdb8250_buf[kgdb8250_buf_in_inx++] = chr ;
+		kgdb8250_buf_in_inx &= (GDB_BUF_SIZE - 1) ;
+		atomic_inc(&kgdb8250_buf_in_cnt) ;
+	}
+	while (iir & UART_IIR_RDI);
+
+	if (atomic_read(&kgdb_killed_or_detached))
+		kgdb8250_interrupt_iteration ++; 
+
+	return IRQ_HANDLED;
+
+}
+
+/* 
+ * Initializes serial port.
+ *	ttyS - integer specifying which serial port to use for debugging
+ *	baud - baud rate of specified serial port
+ */
+static int kgdb8250_init(int ttyS, int baud)
+{
+        unsigned cval;
+        int     bits = 8;
+        int     parity = 'n';
+        int     cflag = CREAD | HUPCL | CLOCAL;
+        int     quot = 0;
+
+        /*
+         *      Now construct a cflag setting.
+         */
+        switch(baud) {
+                case 1200:
+                        cflag |= B1200;
+                        break;
+                case 2400:
+                        cflag |= B2400;
+                        break;
+                case 4800:
+                        cflag |= B4800;
+                        break;
+                case 19200:
+                        cflag |= B19200;
+                        break;
+                case 38400:
+                        cflag |= B38400;
+                        break;
+                case 57600:
+                        cflag |= B57600;
+                        break;
+                case 115200:
+                        cflag |= B115200;
+                        break;
+                default:
+			baud = 9600;
+			/* Fall through */
+                case 9600:
+                        cflag |= B9600;
+                        break;
+        }
+        switch(bits) {
+                case 7:
+                        cflag |= CS7;
+                        break;
+                default:
+                case 8:
+                        cflag |= CS8;
+                        break;
+        }
+        switch(parity) {
+                case 'o': case 'O':
+                        cflag |= PARODD;
+                        break;
+                case 'e': case 'E':
+                        cflag |= PARENB;
+                        break;
+        }
+
+        /*
+         *      Divisor, bytesize and parity
+	 *
+         */
+
+        quot = (1843200/16) / baud;
+        cval = cflag & (CSIZE | CSTOPB);
+        cval >>= 4;
+        if (cflag & PARENB)
+                cval |= UART_LCR_PARITY;
+        if (!(cflag & PARODD))
+                cval |= UART_LCR_EPAR;
+
+
+        /*
+         *      Disable UART interrupts, set DTR and RTS high
+         *      and set speed.
+         */
+	cval = 0x3;
+        serial_outb(cval | UART_LCR_DLAB, kgdb8250_port + UART_LCR);       /* set DLAB */
+        serial_outb(quot & 0xff, kgdb8250_port + UART_DLL);         /* LS of divisor */
+        serial_outb(quot >> 8, kgdb8250_port + UART_DLM);           /* MS of divisor */
+        serial_outb(cval, kgdb8250_port + UART_LCR);                /* reset DLAB */
+        serial_outb(UART_IER_RDI, kgdb8250_port + UART_IER);        /* turn on interrupts*/
+        serial_outb(UART_MCR_OUT2 | UART_MCR_DTR | UART_MCR_RTS, kgdb8250_port + UART_MCR);
+
+        /*
+         *      If we read 0xff from the LSR, there is no UART here.
+         */
+        if (serial_inb(kgdb8250_port + UART_LSR) == 0xff)
+                return -ENODEV;
+        return 0;
+}
+
+int kgdb8250_hook(void)
+{
+	int retval;
+
+	/*
+	 * Set port and irq number.
+	 */
+	kgdb8250_irq = rs_table[kgdb8250_ttyS].irq;
+	switch(rs_table[kgdb8250_ttyS].iotype)
+	{
+	case SERIAL_IO_MEM:
+		kgdb8250_port = (unsigned long)rs_table[kgdb8250_ttyS].membase;
+		serial_inb = direct_inb;
+		serial_outb = direct_outb;
+		break;
+	default:
+		kgdb8250_port = rs_table[kgdb8250_ttyS].line;
+		serial_inb = io_inb;
+		serial_outb = io_outb;
+	}
+
+#ifdef CONFIG_SERIAL_8250
+	if ((retval = serial8250_release_irq(kgdb8250_irq)) < 0)
+		return retval;
+#endif
+
+	if ((retval = kgdb8250_init(kgdb8250_ttyS, kgdb8250_baud)) < 0)
+		return retval;
+
+	retval = request_irq(kgdb8250_irq, kgdb8250_interrupt, SA_INTERRUPT,
+                         "GDB-stub", NULL);
+	return retval;
+}
+
+void
+kgdb8250_add_port(int i, struct uart_port *serial_req)
+{
+	rs_table[i].iotype = serial_req->iotype;
+	rs_table[i].line = serial_req->line;
+	rs_table[i].membase = serial_req->membase;
+	rs_table[i].regshift = serial_req->regshift;
+}
+
+struct kgdb_serial kgdb8250_serial_driver = {
+	.read_char = kgdb8250_read_char,
+	.write_char = kgdb8250_write_char,
+	.hook = kgdb8250_hook
+};
+
+/*
+ * Syntax for this cmdline option is
+ * kgdb8250=ttyno,baudrate
+ */
+
+static int __init kgdb8250_opt(char *str)
+{
+	if (*str < '0' || *str > '3')
+		goto errout;
+	kgdb8250_ttyS = *str - '0';
+	str++;
+	if (*str != ',')
+		goto errout;
+	str++;
+	kgdb8250_baud = simple_strtoul(str, NULL, 10);
+	if (kgdb8250_baud != 9600 && kgdb8250_baud != 19200 &&
+	    kgdb8250_baud != 38400 && kgdb8250_baud != 57600 &&
+	    kgdb8250_baud != 115200)
+		goto errout;
+	kgdb_serial = &kgdb8250_serial_driver;
+	return 1;
+
+errout:
+	printk("Invalid syntax for option kgdb8250=\n");
+	return 0;
+}
+
+__setup("kgdb8250=", kgdb8250_opt);
--- clean.2.5/drivers/serial/serial_core.c	2004-02-05 01:54:11.000000000 +0100
+++ linux-mm/drivers/serial/serial_core.c	2004-02-16 23:09:06.000000000 +0100
@@ -917,7 +917,11 @@
 static void uart_break_ctl(struct tty_struct *tty, int break_state)
 {
 	struct uart_state *state = tty->driver_data;
-	struct uart_port *port = state->port;
+	struct uart_port *port;
+
+	if (!state)
+		return;
+	port = state->port;
 
 	BUG_ON(!kernel_locked());
 
--- clean.2.5/include/linux/debugger.h	2004-02-17 11:38:14.000000000 +0100
+++ linux-mm/include/linux/debugger.h	2004-02-16 23:09:06.000000000 +0100
@@ -0,0 +1,66 @@
+#ifndef _DEBUGGER_H_
+#define _DEBUGGER_H_
+
+/*
+ * Copyright (C) 2003-2004 Amit S. Kale
+ *
+ * Definition switchout for debuggers
+ */
+
+/*
+ * KGDB
+ */
+#ifdef CONFIG_KGDB
+
+typedef int gdb_debug_hook(int exVector, int signo, int err_code,
+                            struct pt_regs *regs);
+extern gdb_debug_hook  *linux_debug_hook;
+#define	CHK_DEBUGGER(trapnr,signr,error_code,regs,after)			\
+    {									\
+	if (linux_debug_hook != (gdb_debug_hook *) NULL && !user_mode(regs)) \
+	{								\
+		(*linux_debug_hook)(trapnr, signr, error_code, regs) ;	\
+		after;							\
+	}								\
+    }
+
+void kgdb_nmihook(int cpu, void *regs);
+static inline void debugger_nmihook(int cpu, void *regs)
+{
+	kgdb_nmihook(cpu, regs);
+}
+
+void kgdb_entry(void);
+static inline void debugger_entry(void)
+{
+	kgdb_entry();
+}
+
+extern int debugger_step;
+extern atomic_t debugger_active;
+
+/*
+ * No debugger in the kernel
+ */
+#else
+
+#define	CHK_DEBUGGER(trapnr,signr,error_code,regs,after)	
+
+static inline void debugger_nmihook(int cpu, void *regs)
+{
+	/* Do nothing */
+}
+
+static inline void debugger_entry(void)
+{
+	/* Do nothing */
+}
+
+#define debugger_step 0
+static const atomic_t debugger_active = { 0 };
+#define debugger_memerr_expected 0
+
+#endif
+
+
+#endif /* _DEBUGGER_H_ */
--- clean.2.5/include/linux/kgdb.h	2004-02-17 11:38:23.000000000 +0100
+++ linux-mm/include/linux/kgdb.h	2004-02-16 23:09:06.000000000 +0100
@@ -0,0 +1,112 @@
+#ifndef _KGDB_H_
+#define _KGDB_H_
+
+/*
+ * Copyright (C) 2001-2004 Amit S. Kale
+ */
+
+#include <linux/ptrace.h>
+#include <asm/kgdb.h>
+#include <linux/spinlock.h>
+#include <asm/atomic.h>
+#include <linux/debugger.h>
+
+/* To enter the debugger explicitly. */
+void breakpoint(void);
+
+#ifndef KGDB_MAX_NO_CPUS
+#if CONFIG_NR_CPUS > 8
+#error KGDB can handle max 8 CPUs
+#endif
+#define KGDB_MAX_NO_CPUS 8
+#endif
+
+extern atomic_t kgdb_setting_breakpoint;
+extern atomic_t kgdb_killed_or_detached;
+extern atomic_t kgdb_might_be_resumed;
+
+extern struct task_struct *kgdb_usethread, *kgdb_contthread;
+
+enum kgdb_bptype
+{
+	bp_breakpoint = '0',
+	bp_hardware_breakpoint,
+	bp_write_watchpoint,
+	bp_read_watchpoint,
+	bp_access_watchpoint
+};
+
+enum kgdb_bpstate
+{
+       bp_disabled,
+       bp_enabled
+};
+
+struct kgdb_bkpt
+{
+       unsigned long		bpt_addr;
+       unsigned char		saved_instr[BREAK_INSTR_SIZE];
+       enum kgdb_bptype		type;
+       enum kgdb_bpstate	state;
+};
+
+#ifndef BREAK_INSTR_SIZE
+#error BREAK_INSTR_SIZE  needed by kgdb
+#endif
+
+#ifndef MAX_BREAKPOINTS
+#define MAX_BREAKPOINTS        16
+#endif
+
+#define KGDB_HW_BREAKPOINT          1
+
+/* These are functions that the arch specific code can, and in some cases
+ * must, provide. */
+extern int kgdb_arch_init(void);
+extern void regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs);
+extern void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs,struct task_struct *p);
+extern void gdb_regs_to_regs(unsigned long *gdb_regs, struct pt_regs *regs);
+extern void kgdb_printexceptioninfo(int exceptionNo, int errorcode,
+		char *buffer);
+extern void kgdb_disable_hw_debug(struct pt_regs *regs);
+extern void kgdb_post_master_code(struct pt_regs *regs, int eVector,
+		int err_code);
+extern int kgdb_arch_handle_exception(int vector, int signo, int err_code,
+		char *InBuffer, char *outBuffer, struct pt_regs *regs);
+extern int kgdb_arch_set_break(unsigned long addr, int type);
+extern int kgdb_arch_remove_break(unsigned long addr, int type);
+extern void kgdb_correct_hw_break(void);
+extern void kgdb_shadowinfo(struct pt_regs *regs, char *buffer, unsigned threadid);
+extern struct task_struct *kgdb_get_shadow_thread(struct pt_regs *regs,
+		int threadid);
+extern struct pt_regs *kgdb_shadow_regs(struct pt_regs *regs, int threadid);
+
+struct kgdb_arch {
+	unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE];
+	unsigned long flags;
+	unsigned shadowth;
+};			
+
+/* Thread reference */
+typedef unsigned char threadref[8];
+
+struct kgdb_serial {
+	int (*read_char)(void);
+	void (*write_char)(int);
+	void (*flush)(void);
+	int (*hook)(void);
+};
+
+extern struct kgdb_serial *kgdb_serial;
+extern struct kgdb_arch arch_kgdb_ops;
+extern int kgdb_initialized;
+
+struct uart_port;
+
+extern void kgdb8250_add_port(int i, struct uart_port *serial_req);
+
+int kgdb_hex2long(char **ptr, long *longValue);
+char *kgdb_mem2hex(char *mem, char *buf, int count);
+char *kgdb_hex2mem(char *buf, char *mem, int count);
+
+#endif /* _KGDB_H_ */
--- clean.2.5/init/main.c	2004-02-05 01:54:30.000000000 +0100
+++ linux-mm/init/main.c	2004-02-16 23:09:06.000000000 +0100
@@ -39,6 +39,7 @@
 #include <linux/writeback.h>
 #include <linux/cpu.h>
 #include <linux/efi.h>
+#include <linux/debugger.h>
 
 #include <asm/io.h>
 #include <asm/bugs.h>
@@ -580,6 +581,7 @@
 	do_pre_smp_initcalls();
 
 	smp_init();
+	debugger_entry();
 	do_basic_setup();
 
 	prepare_namespace();
--- clean.2.5/kernel/Makefile	2003-10-09 00:14:41.000000000 +0200
+++ linux-mm/kernel/Makefile	2004-02-16 23:09:06.000000000 +0100
@@ -19,6 +19,7 @@
 obj-$(CONFIG_COMPAT) += compat.o
 obj-$(CONFIG_IKCONFIG) += configs.o
 obj-$(CONFIG_IKCONFIG_PROC) += configs.o
+obj-$(CONFIG_KGDB) += kgdbstub.o
 
 ifneq ($(CONFIG_IA64),y)
 # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
--- clean.2.5/kernel/kgdbstub.c	2004-02-17 11:38:39.000000000 +0100
+++ linux-mm/kernel/kgdbstub.c	2004-02-16 23:09:06.000000000 +0100
@@ -0,0 +1,1271 @@
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+/*
+ * Copyright (C) 2000-2001 VERITAS Software Corporation.
+ * Copyright (C) 2002-2004 Timesys Corporation
+ * Copyright (C) 2003-2004 Amit S. Kale
+ * Copyright (C) 2004 Pavel Machek <pavel@suse.cz>
+ *
+ * Restructured KGDB for 2.6 kernels.
+ * thread support, support for multiple processors,support for ia-32(x86) 
+ * hardware debugging, Console support, handling nmi watchdog
+ * - Amit S. Kale ( amitkale@emsyssoft.com )
+ *
+ * Several enhancements by George Anzinger <george@mvista.com>
+ * Generic KGDB Support
+ * Implemented by Anurekh Saxena (anurekh.saxena@timesys.com)
+ * 
+ * Contributor:     Lake Stevens Instrument Division
+ * Written by:      Glenn Engel
+ *  
+ * Modified for 386 by Jim Kingdon, Cygnus Support.
+ * Origianl kgdb, compatibility with 2.1.xx kernel by David Grothe <dave@gcom.com>
+ * Integrated into 2.2.5 kernel by Tigran Aivazian <tigran@sco.com>
+ */
+
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/mm.h>
+#include <asm/system.h>
+#include <asm/ptrace.h>
+#include <asm/uaccess.h>
+#include <linux/kgdb.h>
+#include <asm/atomic.h>
+#include <linux/notifier.h>
+#include <linux/module.h>
+#include <asm/cacheflush.h>
+#ifdef CONFIG_KGDB_CONSOLE
+#include <linux/console.h>
+#endif
+#include <linux/init.h>
+
+extern int pid_max;
+
+#define BUF_THREAD_ID_SIZE 16
+
+/*
+ * kgdb_initialized indicates that kgdb is setup and is all ready to serve
+ * breakpoints and other kernel exceptions. kgdb_connected indicates that kgdb
+ * has connected to kgdb.
+ */
+int kgdb_initialized = 0;
+static volatile int kgdb_connected;
+
+/* If non-zero, wait for a gdb connection when kgdb_entry is called */
+int kgdb_enter = 0;
+
+/* Set to 1 to make kgdb allow access to user addresses. Can be set from gdb
+ * also at runtime. */
+int kgdb_useraccess = 0;
+
+struct kgdb_serial *kgdb_serial;
+
+/*
+ * Holds information about breakpoints in a kernel. These breakpoints are
+ * added and removed by gdb.
+ */
+struct kgdb_bkpt kgdb_break[MAX_BREAKPOINTS];
+
+struct kgdb_arch *kgdb_ops = &arch_kgdb_ops;
+
+static const char hexchars[] = "0123456789abcdef";
+
+static spinlock_t slavecpulocks[KGDB_MAX_NO_CPUS];
+static volatile int procindebug[KGDB_MAX_NO_CPUS];
+atomic_t kgdb_setting_breakpoint;
+atomic_t kgdb_killed_or_detached;
+atomic_t kgdb_might_be_resumed;
+struct task_struct *kgdb_usethread, *kgdb_contthread;
+
+int debugger_step;
+atomic_t debugger_active;
+
+/* This will point to kgdb_handle_exception by default.
+ * The architecture code can override this in its init function
+ */
+gdb_debug_hook *linux_debug_hook;
+
+static char remcomInBuffer[BUFMAX];
+static char remcomOutBuffer[BUFMAX];
+
+/*
+ * The following are the stub functions for code which is arch specific
+ * and can be omitted on some arches
+ * This function will handle the initalization of any architecture specific
+ * hooks.  If there is a suitable early output driver, kgdb_serial
+ * can be pointed at it now.
+ */
+int __attribute__ ((weak))
+kgdb_arch_init(void)
+{
+	return 0;
+}
+
+void __attribute__ ((weak))
+regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+}
+
+void __attribute__ ((weak))
+sleeping_thread_to_gdb_regs(unsigned long *gdb_regs,struct task_struct *p)
+{
+}
+
+void __attribute__ ((weak))
+gdb_regs_to_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+}
+
+void __attribute__ ((weak))
+kgdb_printexceptioninfo(int exceptionNo, int errorcode, char *buffer)
+{
+}
+
+void __attribute__ ((weak))
+kgdb_disable_hw_debug(struct pt_regs *regs)
+{
+}
+
+void __attribute__ ((weak))
+kgdb_post_master_code(struct pt_regs *regs, int eVector, int err_code)
+{
+}
+
+/*
+ * Handle any additional commands.  This must handle the 'c' and 's'
+ * command packets.
+ * Return -1 to loop over other commands, and 0 to exit from KGDB
+ */
+int __attribute__ ((weak))
+kgdb_arch_handle_exception(int vector, int signo, int err_code, char *InBuffer,
+		char *outBuffer, struct pt_regs *regs)
+{
+	return 0;
+}
+
+int __attribute__ ((weak))
+kgdb_arch_set_break(unsigned long addr, int type)
+{
+	return 0;
+}
+
+int __attribute__ ((weak))
+kgdb_arch_remove_break(unsigned long addr, int type)
+{
+	return 0;
+}
+
+void __attribute__ ((weak))
+kgdb_correct_hw_break(void)
+{
+}
+
+void __attribute__ ((weak))
+kgdb_shadowinfo(struct pt_regs *regs, char *buffer, unsigned threadid)
+{
+}
+
+struct task_struct __attribute__ ((weak))
+*kgdb_get_shadow_thread(struct pt_regs *regs, int threadid)
+{
+	return NULL;
+}
+
+struct pt_regs __attribute__ ((weak))
+*kgdb_shadow_regs(struct pt_regs *regs, int threadid)
+{
+	return NULL;
+}
+
+static int hex(char ch)
+{
+	if ((ch >= 'a') && (ch <= 'f'))
+		return (ch - 'a' + 10);
+	if ((ch >= '0') && (ch <= '9'))
+		return (ch - '0');
+	if ((ch >= 'A') && (ch <= 'F'))
+		return (ch - 'A' + 10);
+	return (-1);
+}
+
+/* scan for the sequence $<data>#<checksum>	*/
+static void getpacket(char *buffer)
+{
+	unsigned char checksum;
+	unsigned char xmitcsum;
+	int i;
+	int count;
+	char ch;
+
+	do {
+	/* wait around for the start character, ignore all other characters */
+		while ((ch = (kgdb_serial->read_char() & 0x7f)) != '$');
+		checksum = 0;
+		xmitcsum = -1;
+
+		count = 0;
+
+		/* now, read until a # or end of buffer is found */
+		while (count < (BUFMAX - 1)) {
+			ch = kgdb_serial->read_char() & 0x7f;
+			if (ch == '#')
+				break;
+			checksum = checksum + ch;
+			buffer[count] = ch;
+			count = count + 1;
+		}
+		buffer[count] = 0;
+
+		if (ch == '#') {
+			xmitcsum = hex(kgdb_serial->read_char() & 0x7f) << 4;
+			xmitcsum += hex(kgdb_serial->read_char() & 0x7f);
+
+			if (checksum != xmitcsum)
+				kgdb_serial->write_char('-');	/* failed checksum */
+			else {
+				kgdb_serial->write_char('+');	/* successful transfer */
+				/* if a sequence char is present, reply the sequence ID */
+				if (buffer[2] == ':') {
+					kgdb_serial->write_char(buffer[0]);
+					kgdb_serial->write_char(buffer[1]);
+					/* remove sequence chars from buffer */
+					count = strlen(buffer);
+					for (i = 3; i <= count; i++)
+						buffer[i - 3] = buffer[i];
+				}
+			}
+			if (kgdb_serial->flush)
+				kgdb_serial->flush();
+		}
+	} while (checksum != xmitcsum);
+}
+
+/*
+ * Send the packet in buffer.
+ * Check for gdb connection if asked for.
+ */
+static void putpacket(char *buffer, int checkconnect)
+{
+	unsigned char checksum;
+	int count;
+	char ch;
+	static char gdbseq[] = "$Hc-1#09";
+	int i;
+	int send_count;
+
+	/*  $<packet info>#<checksum>. */
+	do {
+		kgdb_serial->write_char('$');
+		checksum = 0;
+		count = 0;
+		send_count = 0;
+
+		while ((ch = buffer[count])) {
+			kgdb_serial->write_char(ch);
+			checksum += ch;
+			count ++;
+			send_count ++;
+		}
+
+		kgdb_serial->write_char('#');
+		kgdb_serial->write_char(hexchars[checksum >> 4]);
+		kgdb_serial->write_char(hexchars[checksum % 16]);
+		if (kgdb_serial->flush)
+			kgdb_serial->flush();
+
+		i = 0;
+		while ((ch = kgdb_serial->read_char()) == gdbseq[i++] &&
+		       checkconnect) {
+			if (!gdbseq[i]) {
+				kgdb_serial->write_char('+');
+				if (kgdb_serial->flush)
+					kgdb_serial->flush();
+				breakpoint();
+
+				/*
+				 * GDB is available now.
+				 * Retransmit this packet.
+				 */
+				break;
+			}
+		}
+		if (checkconnect && ch == 3) {
+			kgdb_serial->write_char('+');
+			if (kgdb_serial->flush)
+				kgdb_serial->flush();
+			breakpoint();
+		}
+	} while (( ch & 0x7f) != '+');
+
+}
+
+static int get_char(char *addr, unsigned char *data)
+{
+	mm_segment_t fs;
+	int ret = 0;
+	
+	if (!kgdb_useraccess && (unsigned long)addr < TASK_SIZE) {
+		return -EINVAL;
+	}
+	wmb();
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+	
+	if (get_user(*data, addr) != 0) {
+		ret = -EFAULT;
+	}
+	
+	set_fs(fs);
+	return ret;
+}
+
+static int set_char(char *addr, int data)
+{
+	mm_segment_t fs;
+	int ret = 0;
+	
+	if (!kgdb_useraccess && (unsigned long)addr < TASK_SIZE) {
+		return -EINVAL;
+	}
+	wmb();
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	if (put_user(data, addr) != 0) {
+		ret = -EFAULT;
+	}
+	
+	set_fs(fs);
+	return ret;
+}
+
+/*
+ * convert the memory pointed to by mem into hex, placing result in buf
+ * return a pointer to the last char put in buf (null). May return an error.
+ */
+char *kgdb_mem2hex(char *mem, char *buf, int count)
+{
+	int i;
+	unsigned char ch;
+	int error;
+	
+	for (i = 0; i < count; i++) {
+
+		if ((error = get_char(mem++, &ch)) < 0)
+			return ERR_PTR(error);
+		
+		*buf++ = hexchars[ch >> 4];
+		*buf++ = hexchars[ch % 16];
+	}
+	*buf = 0;
+	return (buf);
+}
+
+/*
+ * convert the hex array pointed to by buf into binary to be placed in mem
+ * return a pointer to the character AFTER the last byte written
+ * May return an error.
+ */
+char *kgdb_hex2mem(char *buf, char *mem, int count)
+{
+	int i;
+	unsigned char ch;
+	int error;
+	
+	for (i = 0; i < count; i++) {
+		ch = hex(*buf++) << 4;
+		ch = ch + hex(*buf++);
+		if ((error = set_char(mem++, ch)) < 0) 
+			return ERR_PTR(error);
+	}
+	return (mem);
+}
+
+/*
+ * While we find nice hex chars, build a longValue.
+ * Return number of chars processed.
+ */
+int kgdb_hex2long(char **ptr, long *longValue)
+{
+	int numChars = 0;
+	int hexValue;
+
+	*longValue = 0;
+
+	while (**ptr) {
+		hexValue = hex(**ptr);
+		if (hexValue >= 0) {
+			*longValue = (*longValue << 4) | hexValue;
+			numChars++;
+		} else
+			break;
+
+		(*ptr)++;
+	}
+
+	return (numChars);
+}
+
+static inline char *pack_hex_byte(char *pkt, int byte)
+{
+	*pkt++ = hexchars[(byte >> 4) & 0xf];
+	*pkt++ = hexchars[(byte & 0xf)];
+	return pkt;
+}
+
+static inline void error_packet(char *pkt, int error)
+{
+	error = -error;
+	pkt[0] = 'E';
+	pkt[1] = hexchars[(error / 10)];
+	pkt[2] = hexchars[(error % 10)];
+	pkt[3] = '\0';
+}
+
+static void ok_packet(char *pkt)
+{
+	strcpy(pkt, "OK");
+}
+
+static char *pack_threadid(char *pkt, threadref *id)
+{
+	char *limit;
+	unsigned char *altid;
+
+	altid = (unsigned char *) id;
+	limit = pkt + BUF_THREAD_ID_SIZE;
+	while (pkt < limit)
+		pkt = pack_hex_byte(pkt, *altid++);
+
+	return pkt;
+}
+
+void int_to_threadref(threadref *id, int value)
+{
+	unsigned char *scan;
+
+	scan = (unsigned char *) id;
+	{
+		int i = 4;
+		while (i--)
+			*scan++ = 0;
+	}
+	*scan++ = (value >> 24) & 0xff;
+	*scan++ = (value >> 16) & 0xff;
+	*scan++ = (value >> 8) & 0xff;
+	*scan++ = (value & 0xff);
+}
+
+static struct task_struct *getthread(struct pt_regs *regs,int tid)
+{
+	int i;
+	struct list_head *l;
+	struct task_struct *p;
+	struct pid *pid;
+
+	if (tid >= pid_max + num_online_cpus() + kgdb_ops->shadowth) {
+		return NULL;
+	}
+	if (tid >= pid_max + num_online_cpus()) {
+		return kgdb_get_shadow_thread(regs, tid - pid_max -
+				num_online_cpus());
+	}
+	if (tid >= pid_max) {
+		i = 0;
+		for_each_task_pid(0, PIDTYPE_PID, p, l, pid) {
+			if (tid == pid_max + i) {
+				return p;
+			}
+			i++;
+		}
+		return NULL;
+	}
+	if (!tid) {
+		return NULL;
+	}
+	return find_task_by_pid(tid);
+}
+
+#ifdef CONFIG_SMP
+void kgdb_wait(struct pt_regs *regs)
+{
+	unsigned long flags;
+	int processor;
+
+	local_irq_save(flags);
+	processor = smp_processor_id();
+	procindebug[processor] = 1;
+	current->thread.debuggerinfo = regs;
+
+	/* Wait till master processor goes completely into the debugger. FIXME: this looks racy */
+	while (!procindebug[atomic_read(&debugger_active) - 1]) {
+		int i = 10;	/* an arbitrary number */
+
+		while (--i)
+			asm volatile ("nop": : : "memory");
+		barrier();
+	}
+
+	/* Wait till master processor is done with debugging */
+	spin_lock(slavecpulocks + processor);
+
+	/* This has been taken from x86 kgdb implementation and
+	 * will be needed by architectures that have SMP support
+	 */
+	kgdb_correct_hw_break();
+
+	/* Signal the master processor that we are done */
+	procindebug[processor] = 0;
+	spin_unlock(slavecpulocks + processor);
+	local_irq_restore(flags);
+}
+#endif
+
+static int get_mem (char *addr, unsigned char *buf, int count)
+{
+	int error;
+	while (count) {
+		if((error = get_char(addr++, buf)) <  0) 
+			return error;
+		buf++;
+		count--;
+	}
+	return 0;
+}
+
+static int set_mem (char *addr,unsigned char *buf, int count)
+{
+	int error;
+	while (count) {
+		if ((error = set_char(addr++,*buf++)) < 0) 
+			return error;
+		count--;
+	}
+	return 0;
+}
+
+static int set_break (unsigned long addr)
+{
+	int i, breakno = -1;
+	int error;
+
+	for (i = 0; i < MAX_BREAKPOINTS; i++) {
+		if ((kgdb_break[i].state == bp_enabled) &&
+		    (kgdb_break[i].bpt_addr == addr)) {
+			return -EEXIST;
+		}
+
+		if (kgdb_break[i].state == bp_disabled) {
+			if ((breakno == -1) || (kgdb_break[i].bpt_addr == addr))
+				breakno = i;
+		}
+	}
+	if (breakno == -1)
+		return -E2BIG;
+
+	if ((error = get_mem((char *)addr, kgdb_break[breakno].saved_instr,
+				BREAK_INSTR_SIZE)) < 0)
+		return error;
+
+	if ((error = set_mem((char *)addr, kgdb_ops->gdb_bpt_instr,
+					BREAK_INSTR_SIZE)) < 0)
+		return error;
+	flush_cache_range (current->mm, addr, addr + BREAK_INSTR_SIZE);
+	flush_icache_range (addr, addr + BREAK_INSTR_SIZE);
+
+	kgdb_break[breakno].state = bp_enabled;
+	kgdb_break[breakno].type = bp_breakpoint;
+	kgdb_break[breakno].bpt_addr = addr;
+	
+	return 0;
+}	
+
+static int remove_break (unsigned long addr)
+{
+	int i;
+	int error;
+
+	for (i=0; i < MAX_BREAKPOINTS; i++) {
+		if ((kgdb_break[i].state == bp_enabled) &&
+		   (kgdb_break[i].bpt_addr == addr)) {
+			if ((error =set_mem((char *)addr, kgdb_break[i].saved_instr,
+			        BREAK_INSTR_SIZE)) < 0)
+				return error;
+			flush_cache_range (current->mm, addr, addr + BREAK_INSTR_SIZE);
+			flush_icache_range (addr, addr + BREAK_INSTR_SIZE);
+			kgdb_break[i].state = bp_disabled;
+			return 0;
+		}
+	}
+	return -ENOENT;
+}
+
+int remove_all_break(void)
+{
+	int i;
+	int error;
+	for (i=0; i < MAX_BREAKPOINTS; i++) {
+		if(kgdb_break[i].state == bp_enabled) {
+			unsigned long addr = kgdb_break[i].bpt_addr;
+			if ((error = set_mem((char *)addr, kgdb_break[i].saved_instr,
+			       BREAK_INSTR_SIZE)) < 0)
+				return error;
+			flush_cache_range (current->mm, addr, addr + BREAK_INSTR_SIZE);
+			flush_icache_range (addr, addr + BREAK_INSTR_SIZE);
+		}
+		kgdb_break[i].state = bp_disabled;
+	}
+	return 0;
+}
+		
+static inline int shadow_pid(int realpid)
+{
+	if (realpid) {
+		return realpid;
+	}
+	return pid_max + smp_processor_id();
+}
+
+/*
+ * This function does all command procesing for interfacing to gdb.
+ *
+ * Locking hierarchy:
+ *	interface locks, if any (begin_session)
+ *	kgdb lock (debugger_active)
+ *
+ */
+int kgdb_handle_exception(int exVector, int signo, int err_code, 
+                     struct pt_regs *linux_regs)
+{
+	unsigned long length, addr;
+	char *ptr;
+	unsigned long flags;
+	unsigned long gdb_regs[NUMREGBYTES / sizeof (unsigned long)];
+	int i;
+	long threadid;
+	threadref thref;
+	struct task_struct *thread = NULL;
+	unsigned procid;
+	static char tmpstr[256];
+	int numshadowth = num_online_cpus() + kgdb_ops->shadowth;
+	long kgdb_usethreadid = 0;
+	int error = 0;
+
+	/* Panic on recursive debugger calls. */
+	if (atomic_read(&debugger_active) == smp_processor_id() + 1) {
+		return 0;
+	}
+
+	/* 
+	 * Interrupts will be restored by the 'trap return' code, except when
+	 * single stepping.
+	 */
+	local_irq_save(flags);
+	
+	/* Hold debugger_active */
+	procid = smp_processor_id();
+	while (cmpxchg(&atomic_read(&debugger_active), 0, (procid + 1)) != 0) {
+		int i = 25;	/* an arbitrary number */
+
+		while (--i)
+			asm volatile ("nop": : : "memory");
+	}
+	
+	debugger_step = 0;
+
+	current->thread.debuggerinfo = linux_regs;
+
+	kgdb_disable_hw_debug(linux_regs);
+
+	for (i = 0; i < num_online_cpus(); i++) {
+		spin_lock(&slavecpulocks[i]);
+	}
+
+	/* spin_lock code is good enough as a barrier so we don't
+	 * need one here */
+	procindebug[smp_processor_id()] = 1;
+
+	/* Clear the out buffer. */
+	memset(remcomOutBuffer, 0, sizeof(remcomOutBuffer));
+
+	/* Master processor is completely in the debugger */
+	kgdb_post_master_code(linux_regs, exVector, err_code);
+
+	if (atomic_read(&kgdb_killed_or_detached) &&
+	    atomic_read(&kgdb_might_be_resumed)) {
+		getpacket(remcomInBuffer);
+		if(remcomInBuffer[0] == 'H' && remcomInBuffer[1] =='c') {
+			remove_all_break();
+			atomic_set(&kgdb_killed_or_detached, 0);
+			ok_packet(remcomOutBuffer);
+		}
+		else
+			return 1;
+	} else {
+
+		/* reply to host that an exception has occurred */
+		ptr = remcomOutBuffer;
+		*ptr++ = 'T';
+		*ptr++ = hexchars[(signo >> 4) % 16];
+		*ptr++ = hexchars[signo % 16];
+		ptr += strlen(strcpy(ptr, "thread:"));
+		int_to_threadref(&thref, shadow_pid(current->pid));
+		ptr = pack_threadid(ptr, &thref);
+		*ptr++ = ';';
+		*ptr = '\0';
+	}		
+
+	putpacket(remcomOutBuffer, 0);
+	kgdb_connected = 1;
+	
+	kgdb_usethread = current;
+	kgdb_usethreadid = shadow_pid(current->pid);
+
+	while (1) {
+		int bpt_type = 0;
+		error = 0;
+
+		/* Clear the out buffer. */
+		memset(remcomOutBuffer, 0, sizeof(remcomOutBuffer));
+
+		getpacket(remcomInBuffer);
+
+		switch (remcomInBuffer[0]) {
+		case '?':
+			remcomOutBuffer[0] = 'S';
+			remcomOutBuffer[1] = hexchars[signo >> 4];
+			remcomOutBuffer[2] = hexchars[signo % 16];
+			break;
+
+		case 'g':	/* return the value of the CPU registers */
+			thread = kgdb_usethread;
+				
+			if (!thread)
+				thread = current;
+			
+			/* All threads that don't have debuggerinfo should be
+			   in __schedule() sleeping, since all other CPUs
+			   are in kgdb_wait, and thus have debuggerinfo. */
+			   
+			if (kgdb_usethreadid >= pid_max + num_online_cpus()) {
+				regs_to_gdb_regs(gdb_regs,
+					kgdb_shadow_regs(linux_regs,
+						kgdb_usethreadid - pid_max -
+						num_online_cpus()));
+			} else if (thread->thread.debuggerinfo) {
+				if ((error = get_char(thread->thread.debuggerinfo,
+					(unsigned char *)gdb_regs)) < 0) {
+					error_packet(remcomOutBuffer, error);
+					break;
+				}
+				regs_to_gdb_regs(gdb_regs,
+					(struct pt_regs *)
+					thread->thread.debuggerinfo);
+			} else {
+				/* Pull stuff saved during 
+				 * switch_to; nothing else is
+				 * accessible (or even particularly relevant).
+				 * This should be enough for a stack trace. */
+				sleeping_thread_to_gdb_regs(gdb_regs, thread);
+			}
+				
+			kgdb_mem2hex((char *) gdb_regs, remcomOutBuffer, NUMREGBYTES);
+			break;
+
+		case 'G':	/* set the value of the CPU registers - return OK */
+			kgdb_hex2mem(&remcomInBuffer[1], (char *) gdb_regs,
+				NUMREGBYTES);
+				
+			if (kgdb_usethread && kgdb_usethread != current)
+				error_packet(remcomOutBuffer, -EINVAL);
+			else {
+				gdb_regs_to_regs(gdb_regs,
+					(struct pt_regs *)
+					current->thread.debuggerinfo);
+				ok_packet(remcomOutBuffer);
+			}
+
+			break;
+
+			/* mAA..AA,LLLL  Read LLLL bytes at address AA..AA */
+		case 'm':
+			ptr = &remcomInBuffer[1];
+			if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' &&
+			    kgdb_hex2long(&ptr, &length) > 0) {
+				if (IS_ERR(ptr = kgdb_mem2hex((char *) addr,
+							remcomOutBuffer,
+							length)))
+					error_packet(remcomOutBuffer,
+							PTR_ERR(ptr));
+			} else
+				error_packet(remcomOutBuffer, -EINVAL);
+			break;
+
+		/* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
+		case 'M':
+			ptr = &remcomInBuffer[1];
+			if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ','
+				&& kgdb_hex2long(&ptr, &length) > 0 &&
+				*(ptr++) == ':') {
+				if (IS_ERR(ptr = kgdb_hex2mem(ptr, (char *)addr,
+							length)))
+					error_packet(remcomOutBuffer,
+							PTR_ERR(ptr));
+			} else
+				error_packet(remcomOutBuffer, -EINVAL);
+			break;
+
+			/* kill or detach. KGDB should treat this like a 
+			 * continue.
+			 */
+		case 'D':
+			if ((error = remove_all_break()) < 0) {
+				error_packet(remcomOutBuffer, error);
+			} else {
+				ok_packet(remcomOutBuffer);
+				kgdb_connected = 0;
+			}
+			putpacket(remcomOutBuffer, 0);
+			goto default_handle;
+
+		case 'k':
+			/* Don't care about error from remove_all_break */
+			remove_all_break();
+			kgdb_connected = 0;
+			goto default_handle;
+
+			/* query */
+		case 'q':
+			switch (remcomInBuffer[1]) {
+			case 's':
+			case 'f':
+				if (memcmp(remcomInBuffer+2, "ThreadInfo",10))
+				{
+					error_packet(remcomOutBuffer,
+							-EINVAL);
+					break;
+				}
+				if (remcomInBuffer[1] == 'f') {
+					threadid = 1;
+				}
+				remcomOutBuffer[0] = 'm';
+				ptr = remcomOutBuffer + 1;
+				for (i = 0; i < 32 && threadid < pid_max +
+						numshadowth; threadid++) {
+					thread = getthread(linux_regs,
+							threadid);
+					if (thread) {
+						int_to_threadref(&thref,
+								threadid);
+						pack_threadid(ptr, &thref);
+						ptr += 16;
+						*(ptr++) = ',';
+						i++;
+					}
+				}
+				break;
+
+			case 'C':
+				/* Current thread id */
+				strcpy(remcomOutBuffer, "QC");
+
+				threadid = shadow_pid(current->pid);
+				
+				int_to_threadref(&thref, threadid);
+				pack_threadid(remcomOutBuffer + 2, &thref);
+				break;
+
+			case 'E':
+				/* Print exception info */
+				kgdb_printexceptioninfo(exVector, err_code,
+						remcomOutBuffer);
+				break;
+			case 'T':
+				if (memcmp(remcomInBuffer+1,
+					"ThreadExtraInfo,",16))
+				{
+					error_packet(remcomOutBuffer, -EINVAL);
+					break;
+				}
+				threadid = 0;
+				ptr = remcomInBuffer+17;
+				kgdb_hex2long(&ptr, &threadid);
+				if (!getthread(linux_regs, threadid)) {
+					error_packet(remcomOutBuffer, -EINVAL);
+					break;
+				}
+				if (threadid < pid_max) {
+					kgdb_mem2hex(getthread(linux_regs,
+						threadid)->comm,
+						remcomOutBuffer, 16);
+				} else if (threadid >= pid_max +
+						num_online_cpus()) {
+					kgdb_shadowinfo(linux_regs,
+						remcomOutBuffer,
+						threadid - pid_max -
+						num_online_cpus());
+				} else {
+					sprintf(tmpstr, "Shadow task %d"
+						" for pid 0",
+						(int)(threadid - pid_max));
+					kgdb_mem2hex(tmpstr, remcomOutBuffer,
+							strlen(tmpstr));
+				}
+				break;
+			}
+			break;
+
+			/* task related */
+		case 'H':
+			switch (remcomInBuffer[1]) {
+			case 'g':
+				ptr = &remcomInBuffer[2];
+				kgdb_hex2long(&ptr, &threadid);
+				thread = getthread(linux_regs, threadid);
+				if (!thread && threadid > 0) {
+					error_packet(remcomOutBuffer, -EINVAL);
+					break;
+				}
+				kgdb_usethread = thread;
+				kgdb_usethreadid = threadid;
+				ok_packet(remcomOutBuffer);
+				break;
+
+			case 'c':
+				atomic_set(&kgdb_killed_or_detached, 0);
+				ptr = &remcomInBuffer[2];
+				kgdb_hex2long(&ptr, &threadid);
+				if (!threadid) {
+					kgdb_contthread = 0;
+				} else {
+					thread = getthread(linux_regs, threadid);
+					if (!thread && threadid > 0) {
+						error_packet(remcomOutBuffer,
+								-EINVAL);
+						break;
+					}
+					kgdb_contthread = thread;
+				}
+				ok_packet(remcomOutBuffer);
+				break;
+			}
+			break;
+
+			/* Query thread status */
+		case 'T':
+			ptr = &remcomInBuffer[1];
+			kgdb_hex2long(&ptr, &threadid);
+			thread = getthread(linux_regs, threadid);
+			if (thread)
+				ok_packet(remcomOutBuffer);
+			else
+				error_packet(remcomOutBuffer, -EINVAL);
+			break;
+		case 'z':
+		case 'Z':
+			ptr = &remcomInBuffer[2];
+			if (*(ptr++) != ',') {
+				error_packet(remcomOutBuffer, -EINVAL);
+				break;
+			}
+			kgdb_hex2long(&ptr, &addr);
+			
+			bpt_type = remcomInBuffer[1];
+			if (bpt_type != bp_breakpoint) {
+				if (bpt_type == bp_hardware_breakpoint && 
+				    !(kgdb_ops->flags & KGDB_HW_BREAKPOINT))
+					break;
+
+				/* if set_break is not defined, then
+				 * remove_break does not matter
+				 */
+				if(!(kgdb_ops->flags & KGDB_HW_BREAKPOINT))
+					break;
+			}
+			
+			if (remcomInBuffer[0] == 'Z') {
+				if (bpt_type == bp_breakpoint)
+					error = set_break(addr);
+				else
+					error = kgdb_arch_set_break(addr,
+							bpt_type);
+			}
+			else {
+				if (bpt_type == bp_breakpoint)
+					error = remove_break(addr);
+				else
+					error = kgdb_arch_remove_break(addr,
+							bpt_type);
+			}
+			
+			if (error == 0)
+				ok_packet(remcomOutBuffer);
+			else
+				error_packet(remcomOutBuffer, error);
+			
+			break;
+
+		default:
+		default_handle:
+			error = kgdb_arch_handle_exception(exVector, signo,
+					err_code, remcomInBuffer,
+					remcomOutBuffer, linux_regs);
+
+			if(error >= 0 || remcomInBuffer[0] == 'D' ||
+			    remcomInBuffer[0] == 'k')
+				goto kgdb_exit;
+
+
+		} /* switch */
+
+		/* reply to the request */
+		putpacket(remcomOutBuffer, 0);
+	}
+
+kgdb_exit:
+	procindebug[smp_processor_id()] = 0;	
+	
+	for (i = 0; i < num_online_cpus(); i++) {
+		spin_unlock(&slavecpulocks[i]);
+	}
+	/* Wait till all the processors have quit
+	 * from the debugger 
+	 */
+	for (i = 0; i < num_online_cpus(); i++) { 
+		while (procindebug[i]) {
+			int j = 10; /* an arbitrary number */
+
+			while (--j) {
+				asm volatile ("nop" : : : "memory");
+			}
+			barrier();
+		}
+	}
+
+	/* Free debugger_active */
+	atomic_set(&kgdb_killed_or_detached, 1);
+	atomic_set(&debugger_active, 0);
+	local_irq_restore(flags);
+
+	return error;
+}
+
+/*
+ * GDB places a breakpoint at this function to know dynamically
+ * loaded objects. It's not defined static so that only one instance with this
+ * name exists in the kernel.
+ */
+
+int module_event(struct notifier_block * self, unsigned long val, void * data)
+{
+	return 0;
+}
+
+static struct notifier_block kgdb_module_load_nb = {
+	.notifier_call = module_event,
+};
+
+/* This function will generate a breakpoint exception.  It is used at the
+   beginning of a program to sync up with a debugger and can be used
+   otherwise as a quick means to stop program execution and "break" into
+   the debugger. */
+
+void breakpoint(void)
+{
+	if (!kgdb_initialized) {
+		kgdb_enter = 1;
+		kgdb_entry();
+		if (!kgdb_initialized) {
+			printk("kgdb not enabled. Cannot do breakpoint\n");
+			return;
+		}
+	}
+
+	atomic_set(&kgdb_setting_breakpoint, 1);
+	wmb();
+	BREAKPOINT();
+	wmb();
+	atomic_set(&kgdb_setting_breakpoint, 0);
+}
+
+void kgdb_nmihook(int cpu, void *regs)
+{
+#ifdef CONFIG_SMP
+	if (!procindebug[cpu] && atomic_read(&debugger_active) != (cpu + 1)) {
+		kgdb_wait((struct pt_regs *)regs);
+	}
+#endif
+}
+
+void kgdb_entry(void)
+{
+	int i;
+	
+	if (kgdb_initialized) {
+		/* KGDB was initialized */
+		return;
+	}
+
+	for (i = 0; i < KGDB_MAX_NO_CPUS; i++) 
+		spin_lock_init(&slavecpulocks[i]);
+
+	/* Free debugger_active */
+	atomic_set(&debugger_active, 0);
+
+	/* This flag is used, if gdb has detached and wants to start
+	 * another session
+	 */
+	atomic_set(&kgdb_killed_or_detached, 1);
+	atomic_set(&kgdb_might_be_resumed, 0);
+
+	for (i = 0; i < MAX_BREAKPOINTS; i++) 
+		kgdb_break[i].state = bp_disabled;
+
+	linux_debug_hook = kgdb_handle_exception;
+	
+	/* Let the arch do any initalization it needs to, including
+	 * pointing to a suitable early output device. */
+	kgdb_arch_init();
+
+	/* We can't do much if this fails */
+	register_module_notifier(&kgdb_module_load_nb);
+
+	atomic_set(&kgdb_setting_breakpoint, 0);
+
+	if (!kgdb_serial || kgdb_serial->hook() < 0) {
+		/* KGDB interface isn't ready yet */
+		return;
+	}
+	kgdb_initialized = 1;
+	if (!kgdb_enter) {
+		return;
+	}
+	/*
+	 * Call the breakpoint() routine in GDB to start the debugging
+	 * session
+	 */
+	printk(KERN_CRIT "Waiting for connection from remote gdb... ");
+	breakpoint() ;
+	printk("Connected.\n");
+}
+
+#ifdef CONFIG_KGDB_CONSOLE
+char kgdbconbuf[BUFMAX];
+
+void kgdb_console_write(struct console *co, const char *s, unsigned count)
+{
+	int i;
+	int wcount;
+	char *bufptr;
+	unsigned long flags;
+
+	if (!kgdb_connected) {
+		return;
+	}
+	local_irq_save(flags);
+
+	kgdbconbuf[0] = 'O';
+	bufptr = kgdbconbuf + 1;
+	while (count > 0) {
+		if ((count << 1) > (BUFMAX - 2)) {
+			wcount = (BUFMAX - 2) >> 1;
+		} else {
+			wcount = count;
+		}
+		count -= wcount;
+		for (i = 0; i < wcount; i++) {
+			bufptr = pack_hex_byte(bufptr, s[i]);
+		}
+		*bufptr = '\0';
+		s += wcount;
+
+		putpacket(kgdbconbuf, 1);
+
+	}
+	local_irq_restore(flags);
+}
+
+/* Always fail so that kgdb console doesn't become the default console */
+static int __init kgdb_console_setup(struct console *co, char *options)
+{
+	return -1;
+}
+
+static struct console kgdbcons = {
+	.name = "kgdb",
+	.write = kgdb_console_write,
+	.setup = kgdb_console_setup,
+	.flags = CON_PRINTBUFFER | CON_ENABLED,
+	.index = -1,
+};
+
+static int __init kgdb_console_init(void)
+{
+	register_console(&kgdbcons);
+	return 0;
+}
+console_initcall(kgdb_console_init);
+#endif
+
+EXPORT_SYMBOL(breakpoint);
+#ifdef CONFIG_KGDB_THREAD
+EXPORT_SYMBOL(kern_schedule);
+#endif
+
+static int __init opt_kgdb_enter(char *str)
+{
+	kgdb_enter = 1;
+	return 1;
+}
+
+static int __init opt_gdb(char *str)
+{
+	kgdb_enter = 1;
+	return 1;
+}
+
+/*
+ * These options have been deprecated and are present only to maintain
+ * compatibility with kgdb for 2.4 and earlier kernels.
+ */
+#ifdef CONFIG_KGDB_8250
+extern int kgdb8250_baud;
+extern int kgdb8250_ttyS;
+static int __init opt_gdbttyS(char *str)
+{
+	kgdb8250_ttyS = simple_strtoul(str, NULL, 10);
+	return 1;
+}
+static int __init opt_gdbbaud(char *str)
+{
+	kgdb8250_baud = simple_strtoul(str, NULL, 10);
+	return 1;
+}
+#endif
+
+/*
+ *
+ * Sequence of following lines has to be maintained because gdb option is a
+ * prefix of the other two options
+ */
+
+#ifdef CONFIG_KGDB_8250
+__setup("gdbttyS=", opt_gdbttyS);
+__setup("gdbbaud=", opt_gdbbaud);
+#endif
+__setup("gdb", opt_gdb);
+__setup("kgdbwait", opt_kgdb_enter);
--- clean.2.5/kernel/sched.c	2004-02-05 01:54:30.000000000 +0100
+++ linux-mm/kernel/sched.c	2004-02-16 23:09:06.000000000 +0100
@@ -37,6 +37,7 @@
 #include <linux/rcupdate.h>
 #include <linux/cpu.h>
 #include <linux/percpu.h>
+#include <linux/debugger.h>
 
 #ifdef CONFIG_NUMA
 #define cpu_to_node_mask(cpu) node_to_cpumask(cpu_to_node(cpu))
@@ -2958,6 +2959,8 @@
 #if defined(in_atomic)
 	static unsigned long prev_jiffy;	/* ratelimiting */
 
+	if (atomic_read(&debugger_active))
+		return;
 	if ((in_atomic() || irqs_disabled()) && system_running) {
 		if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
 			return;


-- 
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/