Messages in this thread Patch in this message | | | Date | Tue, 17 Feb 2004 12:36:27 +0100 | From | Pavel Machek <> | Subject | 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/
| |