Messages in this thread Patches in this message | | | Date | Wed, 18 Feb 2004 23:50:10 +0100 | From | Pavel Machek <> | Subject | Split kgdb into "lite" and "normal" parts |
| |
Hi!
This is based on current CVS version. If you want just basic functionality, apply core-lite.patch and i386-lite.patch. If you want all the features, add core.patch and i386.patch.
Amit, this should be "step 1: split" we were talking about. Could you test it looks sane and add it to the cvs? Pavel -- When do you have a heart between your knees? [Johanka's followup: and *two* hearts?]--- 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/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 2004-02-17 23:23:05.000000000 +0100 @@ -0,0 +1,1207 @@ +/* + * 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> +#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"); +} + +EXPORT_SYMBOL(breakpoint); + +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;--- clean.2.5/arch/i386/Kconfig 2004-02-05 01:53:54.000000000 +0100 +++ linux-mm/arch/i386/Kconfig 2004-02-16 23:15:53.000000000 +0100 @@ -1253,6 +1253,20 @@ If you say Y here, various routines which may sleep will become very noisy if they are called with a spinlock held. +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. + config FRAME_POINTER bool "Compile the kernel with frame pointers" help --- clean.2.5/arch/i386/kernel/Makefile 2004-01-09 20:24:13.000000000 +0100 +++ linux-mm/arch/i386/kernel/Makefile 2004-02-16 23:09:06.000000000 +0100 @@ -31,6 +31,7 @@ obj-$(CONFIG_ACPI_SRAT) += srat.o obj-$(CONFIG_HPET_TIMER) += time_hpet.o obj-$(CONFIG_EFI) += efi.o efi_stub.o +obj-$(CONFIG_KGDB) += i386-stub.o EXTRA_AFLAGS := -traditional --- clean.2.5/arch/i386/kernel/i386-stub.c 2004-02-17 11:39:06.000000000 +0100 +++ linux-mm/arch/i386/kernel/i386-stub.c 2004-02-16 23:09:06.000000000 +0100 @@ -0,0 +1,373 @@ +/* + * + * 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. + */ +/* + * Contributor: Lake Stevens Instrument Division$ + * Written by: Glenn Engel $ + * Updated by: Amit Kale<akale@veritas.com> + * Modified for 386 by Jim Kingdon, Cygnus Support. + * Origianl kgdb, compatibility with 2.1.xx kernel by David Grothe <dave@gcom.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 <asm/vm86.h> +#include <asm/system.h> +#include <asm/ptrace.h> /* for linux pt_regs struct */ +#include <linux/kgdb.h> +#ifdef CONFIG_GDB_CONSOLE +#include <linux/console.h> +#endif +#include <linux/init.h> +#include <linux/debugger.h> + +/* Put the error code here just in case the user cares. */ +int gdb_i386errcode; +/* Likewise, the vector number here (since GDB only gets the signal + number through the usual means, and that's not very specific). */ +int gdb_i386vector = -1; + +#if KGDB_MAX_NO_CPUS != 8 +#error change the definition of slavecpulocks +#endif + +void regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) +{ + gdb_regs[_EAX] = regs->eax; + gdb_regs[_EBX] = regs->ebx; + gdb_regs[_ECX] = regs->ecx; + gdb_regs[_EDX] = regs->edx; + gdb_regs[_ESI] = regs->esi; + gdb_regs[_EDI] = regs->edi; + gdb_regs[_EBP] = regs->ebp; + gdb_regs[ _DS] = regs->xds; + gdb_regs[ _ES] = regs->xes; + gdb_regs[ _PS] = regs->eflags; + gdb_regs[ _CS] = regs->xcs; + gdb_regs[ _PC] = regs->eip; + gdb_regs[_ESP] = (int) (®s->esp) ; + gdb_regs[ _SS] = __KERNEL_DS; + gdb_regs[ _FS] = 0xFFFF; + gdb_regs[ _GS] = 0xFFFF; +} + +void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) +{ + gdb_regs[_EAX] = 0; + gdb_regs[_EBX] = 0; + gdb_regs[_ECX] = 0; + gdb_regs[_EDX] = 0; + gdb_regs[_ESI] = 0; + gdb_regs[_EDI] = 0; + gdb_regs[_EBP] = *(int *)p->thread.esp; + gdb_regs[_DS] = __KERNEL_DS; + gdb_regs[_ES] = __KERNEL_DS; + gdb_regs[_PS] = 0; + gdb_regs[_CS] = __KERNEL_CS; + gdb_regs[_PC] = p->thread.eip; + gdb_regs[_ESP] = p->thread.esp; + gdb_regs[_SS] = __KERNEL_DS; + gdb_regs[_FS] = 0xFFFF; + gdb_regs[_GS] = 0xFFFF; +} + +void gdb_regs_to_regs(unsigned long *gdb_regs, struct pt_regs *regs) +{ + regs->eax = gdb_regs[_EAX] ; + regs->ebx = gdb_regs[_EBX] ; + regs->ecx = gdb_regs[_ECX] ; + regs->edx = gdb_regs[_EDX] ; + regs->esi = gdb_regs[_ESI] ; + regs->edi = gdb_regs[_EDI] ; + regs->ebp = gdb_regs[_EBP] ; + regs->xds = gdb_regs[ _DS] ; + regs->xes = gdb_regs[ _ES] ; + regs->eflags= gdb_regs[ _PS] ; + regs->xcs = gdb_regs[ _CS] ; + regs->eip = gdb_regs[ _PC] ; +#if 0 /* can't change these */ + regs->esp = gdb_regs[_ESP] ; + regs->xss = gdb_regs[ _SS] ; + regs->fs = gdb_regs[ _FS] ; + regs->gs = gdb_regs[ _GS] ; +#endif + +} + +struct hw_breakpoint { + unsigned enabled; + unsigned type; + unsigned len; + unsigned addr; +} breakinfo[4] = { { +enabled:0}, { +enabled:0}, { +enabled:0}, { +enabled:0}}; + +void kgdb_correct_hw_break(void) +{ + int breakno; + int correctit; + int breakbit; + unsigned dr7; + + asm volatile ("movl %%db7, %0\n":"=r" (dr7) + :); + do { + unsigned addr0, addr1, addr2, addr3; + asm volatile ("movl %%db0, %0\n" + "movl %%db1, %1\n" + "movl %%db2, %2\n" + "movl %%db3, %3\n":"=r" (addr0), "=r"(addr1), + "=r"(addr2), "=r"(addr3):); + } while (0); + correctit = 0; + for (breakno = 0; breakno < 3; breakno++) { + breakbit = 2 << (breakno << 1); + if (!(dr7 & breakbit) && breakinfo[breakno].enabled) { + correctit = 1; + dr7 |= breakbit; + dr7 &= ~(0xf0000 << (breakno << 2)); + dr7 |= (((breakinfo[breakno].len << 2) | + breakinfo[breakno].type) << 16) << + (breakno << 2); + switch (breakno) { + case 0: + asm volatile ("movl %0, %%dr0\n"::"r" + (breakinfo[breakno].addr)); + break; + + case 1: + asm volatile ("movl %0, %%dr1\n"::"r" + (breakinfo[breakno].addr)); + break; + + case 2: + asm volatile ("movl %0, %%dr2\n"::"r" + (breakinfo[breakno].addr)); + break; + + case 3: + asm volatile ("movl %0, %%dr3\n"::"r" + (breakinfo[breakno].addr)); + break; + } + } else if ((dr7 & breakbit) && !breakinfo[breakno].enabled) { + correctit = 1; + dr7 &= ~breakbit; + dr7 &= ~(0xf0000 << (breakno << 2)); + } + } + if (correctit) { + asm volatile ("movl %0, %%db7\n"::"r" (dr7)); + } +} + +int kgdb_remove_hw_break(unsigned long addr, int type) +{ + int i, idx = -1; + for (i = 0; i < 4; i ++) { + if (breakinfo[i].addr == addr && breakinfo[i].enabled) { + idx = i; + break; + } + } + if (idx == -1) + return -1; + + breakinfo[idx].enabled = 0; + return 0; +} + +int kgdb_set_hw_break(unsigned long addr, int type) +{ + int i, idx = -1; + for (i = 0; i < 4; i ++) { + if (!breakinfo[i].enabled) { + idx = i; + break; + } + } + if (idx == -1) + return -1; + + breakinfo[idx].enabled = 1; + breakinfo[idx].type = type; + breakinfo[idx].len = 1; + breakinfo[idx].addr = addr; + return 0; +} + +int remove_hw_break(unsigned breakno) +{ + if (!breakinfo[breakno].enabled) { + return -1; + } + breakinfo[breakno].enabled = 0; + return 0; +} + +int set_hw_break(unsigned breakno, + unsigned type, unsigned len, unsigned addr) +{ + if (breakinfo[breakno].enabled) { + return -1; + } + breakinfo[breakno].enabled = 1; + breakinfo[breakno].type = type; + breakinfo[breakno].len = len; + breakinfo[breakno].addr = addr; + return 0; +} + +void kgdb_printexceptioninfo(int exceptionNo, int errorcode, char *buffer) +{ + unsigned dr6; + int i; + switch (exceptionNo) { + case 1: /* debug exception */ + break; + case 3: /* breakpoint */ + sprintf(buffer, "Software breakpoint"); + return; + default: + sprintf(buffer, "Details not available"); + return; + } + asm volatile ("movl %%db6, %0\n":"=r" (dr6) + :); + if (dr6 & 0x4000) { + sprintf(buffer, "Single step"); + return; + } + for (i = 0; i < 4; ++i) { + if (dr6 & (1 << i)) { + sprintf(buffer, "Hardware breakpoint %d", i); + return; + } + } + sprintf(buffer, "Unknown trap"); + return; +} + +void kgdb_disable_hw_debug(struct pt_regs *regs) +{ + /* Disable hardware debugging while we are in kgdb */ + asm volatile("movl %0,%%db7": /* no output */ : "r"(0)); +} + +void kgdb_post_master_code(struct pt_regs *regs, int eVector, int err_code) +{ + /* Master processor is completely in the debugger */ + gdb_i386vector = eVector; + gdb_i386errcode = err_code; +} + +int kgdb_arch_handle_exception(int exceptionVector, int signo, + int err_code, char *remcomInBuffer, char *remcomOutBuffer, + struct pt_regs *linux_regs) +{ + long addr, length; + long breakno, breaktype; + char *ptr; + int newPC; + int dr6; + + switch (remcomInBuffer[0]) { + case 'c': + case 's': + if (kgdb_contthread && kgdb_contthread != current) { + strcpy(remcomOutBuffer, "E00"); + break; + } + + kgdb_contthread = NULL; + + /* try to read optional parameter, pc unchanged if no parm */ + ptr = &remcomInBuffer[1]; + if (kgdb_hex2long(&ptr, &addr)) { + linux_regs->eip = addr; + } + newPC = linux_regs->eip; + + /* clear the trace bit */ + linux_regs->eflags &= 0xfffffeff; + + /* set the trace bit if we're stepping */ + if (remcomInBuffer[0] == 's') { + linux_regs->eflags |= 0x100; + debugger_step = 1; + } + + asm volatile ("movl %%db6, %0\n" : "=r" (dr6)); + if (!(dr6 & 0x4000)) { + for (breakno = 0; breakno < 4; ++breakno) { + if (dr6 & (1 << breakno)) { + if (breakinfo[breakno].type == 0) { + /* Set restore flag */ + linux_regs->eflags |= 0x10000; + break; + } + } + } + } + kgdb_correct_hw_break(); + asm volatile ("movl %0, %%db6\n"::"r" (0)); + + return (0); + + case 'Y': + ptr = &remcomInBuffer[1]; + kgdb_hex2long(&ptr, &breakno); + ptr++; + kgdb_hex2long(&ptr, &breaktype); + ptr++; + kgdb_hex2long(&ptr, &length); + ptr++; + kgdb_hex2long(&ptr, &addr); + if (set_hw_break(breakno & 0x3, breaktype & 0x3, + length & 0x3, addr) == 0) { + strcpy(remcomOutBuffer, "OK"); + } else { + strcpy(remcomOutBuffer, "ERROR"); + } + break; + + /* Remove hardware breakpoint */ + case 'y': + ptr = &remcomInBuffer[1]; + kgdb_hex2long(&ptr, &breakno); + if (remove_hw_break(breakno & 0x3) == 0) { + strcpy(remcomOutBuffer, "OK"); + } else { + strcpy(remcomOutBuffer, "ERROR"); + } + break; + + } /* switch */ + return -1; /* this means that we do not want to exit from the handler */ +} + +struct kgdb_arch arch_kgdb_ops = { + .gdb_bpt_instr = {0xcc}, + .flags = KGDB_HW_BREAKPOINT, +}; --- clean.2.5/arch/i386/kernel/nmi.c 2003-08-10 21:22:30.000000000 +0200 +++ linux-mm/arch/i386/kernel/nmi.c 2004-02-16 23:09:06.000000000 +0100 @@ -25,6 +25,7 @@ #include <linux/module.h> #include <linux/nmi.h> #include <linux/sysdev.h> +#include <linux/debugger.h> #include <asm/smp.h> #include <asm/mtrr.h> @@ -420,14 +421,25 @@ int sum, cpu = smp_processor_id(); sum = irq_stat[cpu].apic_timer_irqs; + if (atomic_read(&debugger_active)) { - if (last_irq_sums[cpu] == sum) { + /* + * The machine is in debugger, hold this cpu if already + * not held. + */ + debugger_nmihook(cpu, regs); + alert_counter[cpu] = 0; + + } else if (last_irq_sums[cpu] == sum) { /* * Ayiee, looks like this CPU is stuck ... * wait a few IRQs (5 seconds) before doing the oops ... */ alert_counter[cpu]++; if (alert_counter[cpu] == 5*nmi_hz) { + + CHK_DEBUGGER(2,SIGSEGV,0,regs,) + spin_lock(&nmi_print_lock); /* * We are in trouble anyway, lets at least try --- clean.2.5/arch/i386/kernel/signal.c 2003-11-24 17:08:26.000000000 +0100 +++ linux-mm/arch/i386/kernel/signal.c 2004-02-16 23:09:06.000000000 +0100 @@ -580,7 +580,8 @@ * have been cleared if the watchpoint triggered * inside the kernel. */ - __asm__("movl %0,%%db7" : : "r" (current->thread.debugreg[7])); + if (current->thread.debugreg[7]) + __asm__("movl %0,%%db7" : : "r" (current->thread.debugreg[7])); /* Whee! Actually deliver the signal. */ handle_signal(signr, &info, oldset, regs); --- clean.2.5/arch/i386/kernel/traps.c 2003-10-18 20:26:27.000000000 +0200 +++ linux-mm/arch/i386/kernel/traps.c 2004-02-16 23:09:06.000000000 +0100 @@ -51,6 +51,7 @@ #include <linux/irq.h> #include <linux/module.h> +#include <linux/debugger.h> #include "mach_traps.h" @@ -256,6 +257,7 @@ { static int die_counter; + CHK_DEBUGGER(1,SIGTRAP,err,regs,) console_verbose(); spin_lock_irq(&die_lock); bust_spinlocks(1); @@ -330,6 +332,7 @@ #define DO_ERROR(trapnr, signr, str, name) \ asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ { \ + CHK_DEBUGGER(trapnr,signr,error_code,regs,)\ do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \ } @@ -347,7 +350,10 @@ #define DO_VM86_ERROR(trapnr, signr, str, name) \ asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ { \ + CHK_DEBUGGER(trapnr,signr,error_code,regs,goto skip_trap)\ do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \ +skip_trap: \ + return; \ } #define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ @@ -547,7 +553,7 @@ tsk->thread.debugreg[6] = condition; /* Mask out spurious TF errors due to lazy TF clearing */ - if (condition & DR_STEP) { + if (condition & DR_STEP && !debugger_step) { /* * The TF error should be masked out only if the current * process is not traced and if the TRAP flag has been set @@ -570,11 +576,13 @@ info.si_errno = 0; info.si_code = TRAP_BRKPT; - /* If this is a kernel mode trap, save the user PC on entry to - * the kernel, that's what the debugger can make sense of. - */ - info.si_addr = ((regs->xcs & 3) == 0) ? (void *)tsk->thread.eip : - (void *)regs->eip; + + /* If this is a kernel mode trap, we need to reset db7 to allow us + * to continue sanely */ + if ((regs->xcs & 3) == 0) + goto clear_dr7; + + info.si_addr = (void *)regs->eip; force_sig_info(SIGTRAP, &info, tsk); /* Disable additional traps. They'll be re-enabled when @@ -584,6 +592,7 @@ __asm__("movl %0,%%db7" : /* no output */ : "r" (0)); + CHK_DEBUGGER(1,SIGTRAP,error_code,regs,) return; debug_vm86: --- clean.2.5/arch/i386/mm/fault.c 2003-12-21 20:29:03.000000000 +0100 +++ linux-mm/arch/i386/mm/fault.c 2004-02-16 23:09:06.000000000 +0100 @@ -2,6 +2,11 @@ * linux/arch/i386/mm/fault.c * * Copyright (C) 1995 Linus Torvalds + * + * Change History + * + * Tigran Aivazian <tigran@sco.com> Remote debugging support. + * */ #include <linux/signal.h> @@ -21,6 +26,7 @@ #include <linux/vt_kern.h> /* For unblank_screen() */ #include <linux/highmem.h> #include <linux/module.h> +#include <linux/debugger.h> #include <asm/system.h> #include <asm/uaccess.h> @@ -399,6 +405,8 @@ if (is_prefetch(regs, address)) return; + CHK_DEBUGGER(14, SIGSEGV,error_code, regs,) + /* * Oops. The kernel tried to access some bad page. We'll have to * terminate things with extreme prejudice. @@ -406,6 +414,7 @@ bust_spinlocks(1); + if (address < PAGE_SIZE) printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference"); else
--- clean.2.5/include/asm-i386/kgdb.h 2004-02-17 11:39:24.000000000 +0100 +++ linux-mm/include/asm-i386/kgdb.h 2004-02-16 23:09:06.000000000 +0100 @@ -0,0 +1,49 @@ +#ifndef _ASM_KGDB_H_ +#define _ASM_KGDB_H_ + +/* + * Copyright (C) 2001-2004 Amit S. Kale + */ + +#include <linux/ptrace.h> + +/* gdb locks */ +#define KGDB_MAX_NO_CPUS 8 + +/************************************************************************/ +/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/ +/* at least NUMREGBYTES*2 are needed for register packets */ +/* Longer buffer is needed to list all threads */ +#define BUFMAX 1024 + +/* Number of bytes of registers. */ +#define NUMREGBYTES 64 +/* + * Note that this register image is in a different order than + * the register image that Linux produces at interrupt time. + * + * Linux's register image is defined by struct pt_regs in ptrace.h. + * Just why GDB uses a different order is a historical mystery. + */ +enum regnames { _EAX, /* 0 */ + _ECX, /* 1 */ + _EDX, /* 2 */ + _EBX, /* 3 */ + _ESP, /* 4 */ + _EBP, /* 5 */ + _ESI, /* 6 */ + _EDI, /* 7 */ + _PC, /* 8 also known as eip */ + _PS, /* 9 also known as eflags */ + _CS, /* 10 */ + _SS, /* 11 */ + _DS, /* 12 */ + _ES, /* 13 */ + _FS, /* 14 */ + _GS /* 15 */ +}; + +#define BREAKPOINT() asm(" int $3"); +#define BREAK_INSTR_SIZE 1 + +#endif /* _ASM_KGDB_H_ */ --- clean.2.5/include/asm-i386/processor.h 2004-01-09 20:24:24.000000000 +0100 +++ linux-mm/include/asm-i386/processor.h 2004-02-16 23:09:06.000000000 +0100 @@ -425,6 +425,8 @@ unsigned int saved_fs, saved_gs; /* IO permissions */ unsigned long *io_bitmap_ptr; + void * debuggerinfo; + }; #define INIT_THREAD { \--- linux-mm/include/linux/sched.h 2004-02-16 23:18:56.000000000 +0100 +++ clean-mm/include/linux/sched.h 2004-02-16 23:00:15.000000000 +0100 @@ -173,7 +173,9 @@ #define MAX_SCHEDULE_TIMEOUT LONG_MAX extern signed long FASTCALL(schedule_timeout(signed long timeout)); -asmlinkage void schedule(void); +asmlinkage void do_schedule(void); +asmlinkage void kern_schedule(void); +asmlinkage void kern_do_schedule(struct pt_regs); struct namespace; @@ -906,6 +908,15 @@ #endif /* CONFIG_SMP */ +static inline void schedule(void) +{ +#ifdef CONFIG_KGDB_THREAD + kern_schedule(); +#else + do_schedule(); +#endif +} + #endif /* __KERNEL__ */ #endif --- linux-mm/kernel/kgdbstub.c 2004-02-17 23:23:05.000000000 +0100 +++ clean-mm/kernel/kgdbstub.c 2004-02-16 23:00:15.000000000 +0100 @@ -48,6 +48,9 @@ #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; @@ -1160,7 +1163,68 @@ 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) { --- linux-mm/kernel/sched.c 2004-02-16 23:09:06.000000000 +0100 +++ clean-mm/kernel/sched.c 2004-02-16 23:00:15.000000000 +0100 @@ -1589,7 +1589,7 @@ /* * schedule() is the main scheduler function. */ -asmlinkage void schedule(void) +asmlinkage void do_schedule(void) { long *switch_count; task_t *prev, *next; @@ -1761,6 +1761,23 @@ EXPORT_SYMBOL(default_wake_function); +asmlinkage void user_schedule(void) +{ +#ifdef CONFIG_KGDB_THREAD + current->thread.debuggerinfo = NULL; +#endif + do_schedule(); +} + +#ifdef CONFIG_KGDB_THREAD +asmlinkage void kern_do_schedule(struct pt_regs regs) +{ + current->thread.debuggerinfo = ®s; + do_schedule(); + current->thread.debuggerinfo = NULL; +} +#endif + /* * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve--- linux-mm/arch/i386/Kconfig 2004-02-16 23:15:53.000000000 +0100 +++ clean-mm/arch/i386/Kconfig 2004-02-16 23:00:15.000000000 +0100 @@ -1267,6 +1267,23 @@ http://kgdb.sourceforge.net This is only useful for kernel hackers. If unsure, say N. +config KGDB_THREAD + bool "KGDB: Thread analysis" + depends on KGDB + help + With thread analysis enabled, gdb can talk to kgdb stub to list + threads and to get stack trace for a thread. This option also enables + some code which helps gdb get exact status of thread. Thread analysis + adds some overhead to schedule and down functions. You can disable + this option if you do not want to compromise on speed. + +config KGDB_CONSOLE + bool "KGDB: Console messages through gdb" + depends on KGDB + help + If you say Y here, console messages will appear through gdb. + Other consoles such as tty or ttyS will continue to work as usual. + config FRAME_POINTER bool "Compile the kernel with frame pointers" help --- linux-mm/arch/i386/kernel/entry.S 2004-02-17 23:23:55.000000000 +0100 +++ clean-mm/arch/i386/kernel/entry.S 2004-02-16 23:00:15.000000000 +0100 @@ -226,7 +226,7 @@ jz restore_all movl $PREEMPT_ACTIVE,TI_PRE_COUNT(%ebp) sti - call schedule + call user_schedule movl $0,TI_PRE_COUNT(%ebp) cli jmp need_resched @@ -308,7 +308,7 @@ testb $_TIF_NEED_RESCHED, %cl jz work_notifysig work_resched: - call schedule + call user_schedule cli # make sure we don't miss an interrupt # setting need_resched or sigpending # between sampling and the iret @@ -399,7 +399,17 @@ ALIGN common_interrupt: SAVE_ALL + movl %esp, %eax +/* Create a fake function call followed by a fake function prologue to fool + * gdb into believing that this is a normal function call. */ + pushl EIP(%eax) + +common_interrupt_1: + pushl %ebp + movl %esp, %ebp + pushl %eax call do_IRQ + addl $12, %esp jmp ret_from_intr #define BUILD_INTERRUPT(name, nr) \ @@ -606,6 +616,31 @@ pushl $do_spurious_interrupt_bug jmp error_code +#ifdef CONFIG_KGDB_THREAD +ENTRY(kern_schedule) + pushl %ebp + movl %esp, %ebp + pushl %ss + pushl %ebp + pushfl + pushl %cs + pushl 4(%ebp) + pushl %eax + pushl %es + pushl %ds + pushl %eax + pushl (%ebp) + pushl %edi + pushl %esi + pushl %edx + pushl %ecx + pushl %ebx + call kern_do_schedule + movl %ebp, %esp + pop %ebp + ret +#endif + .data ENTRY(sys_call_table) .long sys_restart_syscall /* 0 - old "setup()" system call, used for restarting */ --- linux-mm/arch/i386/kernel/irq.c 2004-02-17 23:23:55.000000000 +0100 +++ clean-mm/arch/i386/kernel/irq.c 2004-02-16 23:00:15.000000000 +0100 @@ -410,7 +410,7 @@ * SMP cross-CPU interrupts have their own specific * handlers). */ -asmlinkage unsigned int do_IRQ(struct pt_regs regs) +asmlinkage unsigned int do_IRQ(struct pt_regs *regs) { /* * We ack quickly, we don't want the irq controller @@ -422,7 +422,7 @@ * 0 return value means that this irq is already being * handled by some other CPU. (or is disabled) */ - int irq = regs.orig_eax & 0xff; /* high bits used in ret_from_ code */ + int irq = regs->orig_eax & 0xff; /* high bits used in ret_from_ code */ irq_desc_t *desc = irq_desc + irq; struct irqaction * action; unsigned int status; @@ -488,7 +488,7 @@ irqreturn_t action_ret; spin_unlock(&desc->lock); - action_ret = handle_IRQ_event(irq, ®s, action); + action_ret = handle_IRQ_event(irq, regs, action); spin_lock(&desc->lock); if (!noirqdebug) note_interrupt(irq, desc, action_ret); | |