Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262434AbUCHJou (ORCPT ); Mon, 8 Mar 2004 04:44:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262430AbUCHJou (ORCPT ); Mon, 8 Mar 2004 04:44:50 -0500 Received: from svr44.ehostpros.com ([66.98.192.92]:44251 "EHLO svr44.ehostpros.com") by vger.kernel.org with ESMTP id S262434AbUCHJkL (ORCPT ); Mon, 8 Mar 2004 04:40:11 -0500 From: "Amit S. Kale" Organization: EmSysSoft To: Andrew Morton , Linux Kernel Subject: kgdb for mainline kernel: core-lite [patch 1/3] Date: Mon, 8 Mar 2004 15:09:10 +0530 User-Agent: KMail/1.5 Cc: Tom Rini , George Anzinger , Pavel Machek MIME-Version: 1.0 Message-Id: <200403081504.30840.amitkale@emsyssoft.com> Content-Type: Multipart/Mixed; boundary="Boundary-00=_+8DTAkqHLfeCzf4" X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - svr44.ehostpros.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - emsyssoft.com Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 42906 Lines: 1666 --Boundary-00=_+8DTAkqHLfeCzf4 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Hi Andrew, Here is kgdb for mainline kernel in three patches. This is a lite version of kgdb available from kgdb.sourceforge.net. I believe that all of us agree on this lite kgdb. It supports basic debugging of i386 architecture and debugging over a serial line. Contents of these patches are as follows: [1] core-lite.patch: architecture indepndent code [2] i386-lite.patch: i386 architecture dependent code [3] 8250.patch: support for generic serial driver Thanks. -Amit --Boundary-00=_+8DTAkqHLfeCzf4 Content-Type: text/x-diff; charset="us-ascii"; name="core-lite.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="core-lite.patch" Index: linux-2.6.4-rc2-bk3-kgdb/Makefile =================================================================== --- linux-2.6.4-rc2-bk3-kgdb.orig/Makefile 2004-03-08 14:30:27.382791896 +0530 +++ linux-2.6.4-rc2-bk3-kgdb/Makefile 2004-03-08 14:31:42.813324712 +0530 @@ -440,6 +440,8 @@ ifndef CONFIG_FRAME_POINTER CFLAGS += -fomit-frame-pointer +else +CFLAGS += -fno-omit-frame-pointer endif ifdef CONFIG_DEBUG_INFO Index: linux-2.6.4-rc2-bk3-kgdb/include/linux/debugger.h =================================================================== --- linux-2.6.4-rc2-bk3-kgdb.orig/include/linux/debugger.h 2003-01-30 15:54:37.000000000 +0530 +++ linux-2.6.4-rc2-bk3-kgdb/include/linux/debugger.h 2004-03-08 14:31:42.814324560 +0530 @@ -0,0 +1,70 @@ +#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) \ +{ \ + if (0) \ + 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_ */ Index: linux-2.6.4-rc2-bk3-kgdb/include/linux/kgdb.h =================================================================== --- linux-2.6.4-rc2-bk3-kgdb.orig/include/linux/kgdb.h 2003-01-30 15:54:37.000000000 +0530 +++ linux-2.6.4-rc2-bk3-kgdb/include/linux/kgdb.h 2004-03-08 14:31:42.814324560 +0530 @@ -0,0 +1,128 @@ +#ifndef _KGDB_H_ +#define _KGDB_H_ + +/* + * Copyright (C) 2001-2004 Amit S. Kale + */ + +#include +#include +#include +#include +#include + +/* + * This file should not include ANY others. This makes it usable + * most anywhere without the fear of include order or inclusion. + * TODO: Make it so! + * + * This file may be included all the time. It is only active if + * CONFIG_KGDB is defined, otherwise it stubs out all the macros + * and entry points. + */ + +#if defined(CONFIG_KGDB) && !defined(__ASSEMBLY__) +/* To enter the debugger explicitly. */ +extern void breakpoint(void); +extern void kgdb_schedule_breakpoint(void); +extern void kgdb_process_breakpoint(void); +extern volatile int kgdb_connected; + +#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 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); +int kgdb_get_mem(char *addr, unsigned char *buf, int count); + +#else +#define kgdb_process_breakpoint() do {} while(0) +#endif /* KGDB && !__ASSEMBLY__ */ +#endif /* _KGDB_H_ */ Index: linux-2.6.4-rc2-bk3-kgdb/init/main.c =================================================================== --- linux-2.6.4-rc2-bk3-kgdb.orig/init/main.c 2004-03-08 14:30:27.283806944 +0530 +++ linux-2.6.4-rc2-bk3-kgdb/init/main.c 2004-03-08 14:31:42.815324408 +0530 @@ -39,6 +39,7 @@ #include #include #include +#include #include #include @@ -581,6 +582,7 @@ smp_init(); do_basic_setup(); + debugger_entry(); prepare_namespace(); Index: linux-2.6.4-rc2-bk3-kgdb/kernel/Makefile =================================================================== --- linux-2.6.4-rc2-bk3-kgdb.orig/kernel/Makefile 2004-03-08 14:30:26.920862120 +0530 +++ linux-2.6.4-rc2-bk3-kgdb/kernel/Makefile 2004-03-08 14:31:42.815324408 +0530 @@ -19,6 +19,7 @@ obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_IKCONFIG) += configs.o obj-$(CONFIG_IKCONFIG_PROC) += configs.o +obj-$(CONFIG_KGDB) += kgdb.o ifneq ($(CONFIG_IA64),y) # According to Alan Modra , the -fno-omit-frame-pointer is Index: linux-2.6.4-rc2-bk3-kgdb/kernel/kgdb.c =================================================================== --- linux-2.6.4-rc2-bk3-kgdb.orig/kernel/kgdb.c 2003-01-30 15:54:37.000000000 +0530 +++ linux-2.6.4-rc2-bk3-kgdb/kernel/kgdb.c 2004-03-08 14:31:42.818323952 +0530 @@ -0,0 +1,1275 @@ +/* + * 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 + * Copyright (C) 2004 Tom Rini + * + * 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 + * 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 + * Integrated into 2.2.5 kernel by Tigran Aivazian + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#ifdef CONFIG_KGDB_CONSOLE +#include +#endif +#include + +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; +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; +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 remcom_in_buffer[BUFMAX]; +static char remcom_out_buffer[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 $# */ +static void get_packet(char *buffer) +{ + unsigned char checksum; + unsigned char xmitcsum; + int i; + int count; + char ch; + + do { + /* wait around for the start character, ignore all other + * characters */ + while ((ch = (kgdb_serial->read_char() & 0x7f)) != '$') + ; /* Spin. */ + kgdb_connected = 1; + 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 (kgdb_serial->flush) + kgdb_serial->flush(); + } + } while (checksum != xmitcsum); +} + +/* + * Send the packet in buffer. + * Check for gdb connection if asked for. + */ +static void put_packet(char *buffer) +{ + unsigned char checksum; + int count; + char ch; + + /* $#. */ + while (1) { + kgdb_serial->write_char('$'); + checksum = 0; + count = 0; + + while ((ch = buffer[count])) { + kgdb_serial->write_char(ch); + checksum += ch; + 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(); + + /* Now see what we get in reply. */ + ch = kgdb_serial->read_char(); + + if (ch == 3) + ch = kgdb_serial->read_char(); + + /* If we get an ACK, we are done. */ + if (ch == '+') + return; + + /* If we get the start of another packet, this means + * that GDB is attempting to reconnect. We will NAK + * the packet being sent, and stop trying to send this + * packet. */ + if (ch == '$') { + kgdb_serial->write_char('-'); + if (kgdb_serial->flush) + kgdb_serial->flush(); + return; + } + } +} + +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 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 + +int kgdb_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 = kgdb_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; + struct pt_regs *shadowregs; + + /* 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(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); + + /* Master processor is completely in the debugger */ + kgdb_post_master_code(linux_regs, exVector, err_code); + + if (kgdb_connected) { + /* reply to host that an exception has occurred */ + ptr = remcom_out_buffer; + *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++ = ';'; + + put_packet(remcom_out_buffer); + } + + kgdb_usethread = current; + kgdb_usethreadid = shadow_pid(current->pid); + + while (1) { + int bpt_type = 0; + error = 0; + + /* Clear the out buffer. */ + memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); + + get_packet(remcom_in_buffer); + + switch (remcom_in_buffer[0]) { + case '?': + /* We know that this packet is only sent + * during initial connect. So to be safe, + * we clear out our breakpoints now incase + * GDB is reconnecting. */ + remove_all_break(); + remcom_out_buffer[0] = 'S'; + remcom_out_buffer[1] = hexchars[signo >> 4]; + remcom_out_buffer[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()) { + shadowregs = kgdb_shadow_regs(linux_regs, + kgdb_usethreadid - + pid_max - + num_online_cpus + ()); + if (!shadowregs) { + error_packet(remcom_out_buffer, + -EINVAL); + break; + } + regs_to_gdb_regs(gdb_regs, shadowregs); + } else if (thread->thread.debuggerinfo) { + if ((error = + get_char(thread->thread.debuggerinfo, + (unsigned char *)gdb_regs)) < 0) { + error_packet(remcom_out_buffer, 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, remcom_out_buffer, + NUMREGBYTES); + break; + + case 'G': /* set the value of the CPU registers - return OK */ + kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, + NUMREGBYTES); + + if (kgdb_usethread && kgdb_usethread != current) + error_packet(remcom_out_buffer, -EINVAL); + else { + gdb_regs_to_regs(gdb_regs, (struct pt_regs *) + current->thread.debuggerinfo); + strcpy(remcom_out_buffer, "OK"); + } + + break; + + /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ + case 'm': + ptr = &remcom_in_buffer[1]; + if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' && + kgdb_hex2long(&ptr, &length) > 0) { + if (IS_ERR(ptr = kgdb_mem2hex((char *)addr, + remcom_out_buffer, + length))) + error_packet(remcom_out_buffer, + PTR_ERR(ptr)); + } else + error_packet(remcom_out_buffer, -EINVAL); + break; + + /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */ + case 'M': + ptr = &remcom_in_buffer[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(remcom_out_buffer, + PTR_ERR(ptr)); + } else + error_packet(remcom_out_buffer, -EINVAL); + break; + + /* kill or detach. KGDB should treat this like a + * continue. + */ + case 'D': + if ((error = remove_all_break()) < 0) { + error_packet(remcom_out_buffer, error); + } else { + strcpy(remcom_out_buffer, "OK"); + kgdb_connected = 0; + } + put_packet(remcom_out_buffer); + 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 (remcom_in_buffer[1]) { + case 's': + case 'f': + if (memcmp + (remcom_in_buffer + 2, "ThreadInfo", 10)) { + error_packet(remcom_out_buffer, + -EINVAL); + break; + } + if (remcom_in_buffer[1] == 'f') { + threadid = 1; + } + remcom_out_buffer[0] = 'm'; + ptr = remcom_out_buffer + 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++; + } + } + *(--ptr) = '\0'; + break; + + case 'C': + /* Current thread id */ + strcpy(remcom_out_buffer, "QC"); + + threadid = shadow_pid(current->pid); + + int_to_threadref(&thref, threadid); + pack_threadid(remcom_out_buffer + 2, &thref); + break; + + case 'E': + /* Print exception info */ + kgdb_printexceptioninfo(exVector, err_code, + remcom_out_buffer); + break; + case 'T': + if (memcmp(remcom_in_buffer + 1, + "ThreadExtraInfo,", 16)) { + error_packet(remcom_out_buffer, + -EINVAL); + break; + } + threadid = 0; + ptr = remcom_in_buffer + 17; + kgdb_hex2long(&ptr, &threadid); + if (!getthread(linux_regs, threadid)) { + error_packet(remcom_out_buffer, + -EINVAL); + break; + } + if (threadid < pid_max) { + kgdb_mem2hex(getthread(linux_regs, + threadid)->comm, + remcom_out_buffer, 16); + } else if (threadid >= pid_max + + num_online_cpus()) { + kgdb_shadowinfo(linux_regs, + remcom_out_buffer, + threadid - pid_max - + num_online_cpus()); + } else { + sprintf(tmpstr, "Shadow task %d" + " for pid 0", + (int)(threadid - pid_max)); + kgdb_mem2hex(tmpstr, remcom_out_buffer, + strlen(tmpstr)); + } + break; + } + break; + + /* task related */ + case 'H': + switch (remcom_in_buffer[1]) { + case 'g': + ptr = &remcom_in_buffer[2]; + kgdb_hex2long(&ptr, &threadid); + thread = getthread(linux_regs, threadid); + if (!thread && threadid > 0) { + error_packet(remcom_out_buffer, + -EINVAL); + break; + } + kgdb_usethread = thread; + kgdb_usethreadid = threadid; + strcpy(remcom_out_buffer, "OK"); + break; + + case 'c': + ptr = &remcom_in_buffer[2]; + kgdb_hex2long(&ptr, &threadid); + if (!threadid) { + kgdb_contthread = 0; + } else { + thread = + getthread(linux_regs, threadid); + if (!thread && threadid > 0) { + error_packet(remcom_out_buffer, + -EINVAL); + break; + } + kgdb_contthread = thread; + } + strcpy(remcom_out_buffer, "OK"); + break; + } + break; + + /* Query thread status */ + case 'T': + ptr = &remcom_in_buffer[1]; + kgdb_hex2long(&ptr, &threadid); + thread = getthread(linux_regs, threadid); + if (thread) + strcpy(remcom_out_buffer, "OK"); + else + error_packet(remcom_out_buffer, -EINVAL); + break; + case 'z': + case 'Z': + ptr = &remcom_in_buffer[2]; + if (*(ptr++) != ',') { + error_packet(remcom_out_buffer, -EINVAL); + break; + } + kgdb_hex2long(&ptr, &addr); + + bpt_type = remcom_in_buffer[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 (remcom_in_buffer[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) + strcpy(remcom_out_buffer, "OK"); + else + error_packet(remcom_out_buffer, error); + + break; + + default: + default_handle: + error = kgdb_arch_handle_exception(exVector, signo, + err_code, + remcom_in_buffer, + remcom_out_buffer, + linux_regs); + + if (error >= 0 || remcom_in_buffer[0] == 'D' || + remcom_in_buffer[0] == 'k') + goto kgdb_exit; + + } /* switch */ + + /* reply to the request */ + put_packet(remcom_out_buffer); + } + + 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(&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); + + 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"); +} + +/* + * Sometimes we need to schedule a breakpoint because we can't break + * right where we are. + */ +static int kgdb_need_breakpoint[NR_CPUS]; + +void kgdb_schedule_breakpoint(void) +{ + kgdb_need_breakpoint[smp_processor_id()] = 1; +} + +void kgdb_process_breakpoint(void) +{ + /* + * Handle a breakpoint queued from inside network driver code + * to avoid reentrancy issues + */ + if (kgdb_need_breakpoint[smp_processor_id()]) { + kgdb_need_breakpoint[smp_processor_id()] = 0; + breakpoint(); + } +} + +#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; + + put_packet(kgdbconbuf); + + } + 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); Index: linux-2.6.4-rc2-bk3-kgdb/kernel/sched.c =================================================================== --- linux-2.6.4-rc2-bk3-kgdb.orig/kernel/sched.c 2004-03-08 14:30:26.958856344 +0530 +++ linux-2.6.4-rc2-bk3-kgdb/kernel/sched.c 2004-03-08 14:31:42.819323800 +0530 @@ -37,6 +37,7 @@ #include #include #include +#include #ifdef CONFIG_NUMA #define cpu_to_node_mask(cpu) node_to_cpumask(cpu_to_node(cpu)) @@ -2961,6 +2962,8 @@ #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; Index: linux-2.6.4-rc2-bk3-kgdb/kernel/Kconfig.kgdb =================================================================== --- linux-2.6.4-rc2-bk3-kgdb.orig/kernel/Kconfig.kgdb 2003-01-30 15:54:37.000000000 +0530 +++ linux-2.6.4-rc2-bk3-kgdb/kernel/Kconfig.kgdb 2004-03-08 14:31:42.820323648 +0530 @@ -0,0 +1,13 @@ +config KGDB + bool "KGDB: kernel debugging with remote gdb" + depends on DEBUG_KERNEL + select DEBUG_INFO + select FRAME_POINTER + help + If you say Y here, it will be possible to remotely debug the + kernel using gdb. This enlarges your kernel image disk size by + several megabytes and requires a machine with more than 128 MB + RAM to avoid excessive linking time. + Documentation of kernel debugger available at + http://kgdb.sourceforge.net + This is only useful for kernel hackers. If unsure, say N. Index: linux-2.6.4-rc2-bk3-kgdb/Documentation/kgdb.txt =================================================================== --- linux-2.6.4-rc2-bk3-kgdb.orig/Documentation/kgdb.txt 2003-01-30 15:54:37.000000000 +0530 +++ linux-2.6.4-rc2-bk3-kgdb/Documentation/kgdb.txt 2004-03-08 14:31:42.820323648 +0530 @@ -0,0 +1,49 @@ +KGDB Linux kernel source level debugger + +Amit S. Kale +Last updated March 2004. + +Introduction: +kgdb is a source level debugger for linux kernel. It is used along with gdb to +debug a linux kernel. Kernel developers can debug a kernel similar to +application programs with the use of kgdb. It makes it possible to place +breakpoints in kernel code, step through the code and observe variables. + +Two machines are required for using kgdb. One of these machines is a +development machine and the other is a test machine. The machines are +connected through a serial line, a null-modem cable which connects their +serial ports. The kernel to be debugged runs on the test machine. gdb runs on +the development machine. The serial line is used by gdb to communicate to the +kernel being debugged. + +This version of kgdb is a lite version. It is available on i386 platform uses +a serial line for communicating to gdb. Full kgdb containing more features and +supporting more architecture is available along with plenty of documentation +at http://kgdb.sourceforge.net/ + +Compiling a kernel: +Enable Kernel hacking -> Kernel Debugging -> KGDB: kernel debugging with +remote gdb + +Only generic serial port (8250) is supported in the lite version. Configure +8250 options. + +Booting the kernel: +Kernel command line option "kgdbwait" makes kgdb wait for gdb connection +during booting of a kernel. If you have configured simple serial port, the +port number and speed can be overriden on command line by using option +"kgdb8250=portnumber,speed", where port numbers are 0-3 for COM1 to COM4 +respectively and supported speeds are 9600, 19200, 38400, 57600, 115200. +Example: kgdbwait kgdb8250=0,115200 + +Connecting gdb: +If you have used "kgdbwait", kgdb prints a message "Waiting for connection +from remote gdb..." on the console and waits for connection from gdb. At this +point you connect gdb to kgdb. +Example: + % gdb ./vmlinux + (gdb) set remotebaud 115200 + (gdb) target remote /dev/ttyS0 + +Once connected, you can debug a kernel the way you would debug an application +program. --Boundary-00=_+8DTAkqHLfeCzf4-- - 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/