[patch 2/8] KGDB support for i386

From: Tom Rini (trini_at_kernel.crashing.org)
Date: 10/29/04

  • Next message: Tom Rini: "[patch 3/8] KGDB support for ppc32"
    To: akpm@osdl.org
    Date:	Fri, 29 Oct 2004 11:33:18 -0700
    
    

    This adds support for KGDB on the i386 architecture. The only slightly
    related change is to make i386 parse early_params now as KGDB registers as
    one. We also add an early_trap_init() call which does the parts of
    trap_init() which need to be done for KGDB to be entered, and can be done
    safely this early.

    As an aside, I believe the hunk to arch/i386/kernel/signal.c can be dropped in
    a post 2.6.10-rc1 tree as something similar using unlikey() has been put in.

    ---
     linux-2.6.10-rc1-trini/arch/i386/kernel/Makefile |    1 
     linux-2.6.10-rc1-trini/arch/i386/kernel/irq.c    |    3 
     linux-2.6.10-rc1-trini/arch/i386/kernel/kgdb.c   |  300 +++++++++++++++++++++++
     linux-2.6.10-rc1-trini/arch/i386/kernel/nmi.c    |   11 
     linux-2.6.10-rc1-trini/arch/i386/kernel/setup.c  |    3 
     linux-2.6.10-rc1-trini/arch/i386/kernel/signal.c |    3 
     linux-2.6.10-rc1-trini/arch/i386/kernel/traps.c  |   31 +-
     linux-2.6.10-rc1-trini/arch/i386/mm/fault.c      |   10 
     linux-2.6.10-rc1-trini/include/asm-i386/kgdb.h   |   48 +++
     linux-2.6.10-rc1-trini/include/asm-i386/system.h |   10 
     linux-2.6.10-rc1-trini/lib/Kconfig.debug         |    2 
     11 files changed, 405 insertions(+), 17 deletions(-)
    diff -puN arch/i386/kernel/Makefile~i386-lite arch/i386/kernel/Makefile
    --- linux-2.6.10-rc1/arch/i386/kernel/Makefile~i386-lite	2004-10-29 11:26:44.461448834 -0700
    +++ linux-2.6.10-rc1-trini/arch/i386/kernel/Makefile	2004-10-29 11:26:44.481444139 -0700
    @@ -32,6 +32,7 @@ obj-$(CONFIG_ACPI_SRAT) 	+= srat.o
     obj-$(CONFIG_HPET_TIMER) 	+= time_hpet.o
     obj-$(CONFIG_EFI) 		+= efi.o efi_stub.o
     obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
    +obj-$(CONFIG_KGDB)		+= kgdb.o
     
     EXTRA_AFLAGS   := -traditional
     
    diff -puN arch/i386/kernel/irq.c~i386-lite arch/i386/kernel/irq.c
    --- linux-2.6.10-rc1/arch/i386/kernel/irq.c~i386-lite	2004-10-29 11:26:44.463448364 -0700
    +++ linux-2.6.10-rc1-trini/arch/i386/kernel/irq.c	2004-10-29 11:26:44.482443904 -0700
    @@ -15,6 +15,7 @@
     #include <linux/seq_file.h>
     #include <linux/interrupt.h>
     #include <linux/kernel_stat.h>
    +#include <linux/kgdb.h>
     
     #ifndef CONFIG_X86_LOCAL_APIC
     /*
    @@ -103,6 +104,8 @@ asmlinkage unsigned int do_IRQ(struct pt
     
     	irq_exit();
     
    +	kgdb_process_breakpoint();
    +
     	return 1;
     }
     
    diff -puN /dev/null arch/i386/kernel/kgdb.c
    --- /dev/null	2004-10-25 00:35:20.587727328 -0700
    +++ linux-2.6.10-rc1-trini/arch/i386/kernel/kgdb.c	2004-10-29 11:26:44.482443904 -0700
    @@ -0,0 +1,300 @@
    +/*
    + *
    + * 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>
    +#include <linux/init.h>
    +#include <linux/debugger.h>
    +#include <asm/desc.h>
    +#include <asm/kdebug.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;
    +
    +extern atomic_t cpu_doing_single_step;
    +
    +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)(&regs->esp);
    +	gdb_regs[_SS] = __KERNEL_DS;
    +	gdb_regs[_FS] = 0xFFFF;
    +	gdb_regs[_GS] = 0xFFFF;
    +}
    +
    +/*
    + * Extracts ebp, esp and eip values understandable by gdb from the values
    + * saved by switch_to.
    + * thread.esp points to ebp. flags and ebp are pushed in switch_to hence esp
    + * prior to entering switch_to is 8 greater then the value that is saved.
    + * If switch_to changes, change following code appropriately.
    + */
    +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] = *(unsigned long *)p->thread.esp;
    +	gdb_regs[_DS] = __KERNEL_DS;
    +	gdb_regs[_ES] = __KERNEL_DS;
    +	gdb_regs[_PS] = *(unsigned long *)(p->thread.esp + 4);
    +	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));
    +	}
    +}
    +
    +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 *remcom_in_buffer,
    +			       char *remcom_out_buffer,
    +			       struct pt_regs *linux_regs)
    +{
    +	long addr;
    +	long breakno;
    +	char *ptr;
    +	int newPC;
    +	int dr6;
    +
    +	switch (remcom_in_buffer[0]) {
    +	case 'c':
    +	case 's':
    +		if (kgdb_contthread && kgdb_contthread != current) {
    +			strcpy(remcom_out_buffer, "E00");
    +			break;
    +		}
    +
    +		/* try to read optional parameter, pc unchanged if no parm */
    +		ptr = &remcom_in_buffer[1];
    +		if (kgdb_hex2long(&ptr, &addr)) {
    +			linux_regs->eip = addr;
    +		}
    +		newPC = linux_regs->eip;
    +
    +		/* clear the trace bit */
    +		linux_regs->eflags &= ~TF_MASK;
    +		atomic_set(&cpu_doing_single_step,-1);
    +
    +		/* set the trace bit if we're stepping */
    +		if (remcom_in_buffer[0] == 's') {
    +			linux_regs->eflags |= TF_MASK;
    +			debugger_step = 1;
    +			if (kgdb_contthread)
    +				atomic_set(&cpu_doing_single_step,smp_processor_id());
    +		}
    +
    +		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 |= X86_EFLAGS_RF;
    +						break;
    +					}
    +				}
    +			}
    +		}
    +		kgdb_correct_hw_break();
    +		asm volatile ("movl %0, %%db6\n"::"r" (0));
    +
    +		return (0);
    +	}			/* switch */
    +	return -1;		/* this means that we do not want to exit from the handler */
    +}
    +
    +/* Register KGDB with the i386die_chain so that we hook into all of the right
    + * spots. */
    +static int kgdb_notify(struct notifier_block *self, unsigned long cmd,
    +		void *ptr)
    +{
    +	struct die_args *args = (struct die_args *)ptr;
    +	struct pt_regs *regs = args->regs;
    +
    +	/* See if KGDB is interested. */
    +	if (cmd == DIE_PAGE_FAULT)
    +		return NOTIFY_DONE;
    +	else if (user_mode(regs)) {
    +		if (cmd == DIE_OOPS)
    +			CHK_DEBUGGER(args->trapnr, args->signr, args->err,
    +					args->regs,);
    +		return NOTIFY_DONE;
    +	} else if (cmd == DIE_NMI_IPI) {
    +		if (atomic_read(&debugger_active)) {
    +			debugger_nmihook(smp_processor_id(), ptr);
    +			return NOTIFY_STOP;
    +		}
    +	}
    +
    +	CHK_DEBUGGER(args->trapnr, args->signr, args->err, args->regs,);
    +
    +	return NOTIFY_STOP;
    +}
    +
    +static struct notifier_block kgdb_notifier = {
    +	.notifier_call = kgdb_notify,
    +};
    +
    +int kgdb_arch_init(void) {
    +	notifier_chain_register(&i386die_chain, &kgdb_notifier);
    +	return 0;
    +}
    +
    +struct kgdb_arch arch_kgdb_ops = {
    +	.gdb_bpt_instr = {0xcc},
    +};
    diff -puN arch/i386/kernel/nmi.c~i386-lite arch/i386/kernel/nmi.c
    --- linux-2.6.10-rc1/arch/i386/kernel/nmi.c~i386-lite	2004-10-29 11:26:44.465447895 -0700
    +++ linux-2.6.10-rc1-trini/arch/i386/kernel/nmi.c	2004-10-29 11:26:44.483443669 -0700
    @@ -26,6 +26,7 @@
     #include <linux/nmi.h>
     #include <linux/sysdev.h>
     #include <linux/sysctl.h>
    +#include <linux/debugger.h>
     
     #include <asm/smp.h>
     #include <asm/mtrr.h>
    @@ -481,7 +482,15 @@ void nmi_watchdog_tick (struct pt_regs *
     
     	sum = irq_stat[cpu].apic_timer_irqs;
     
    -	if (last_irq_sums[cpu] == sum) {
    +	if (atomic_read(&debugger_active)) {
    +		/*
    +		 * 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 ...
    diff -puN arch/i386/kernel/setup.c~i386-lite arch/i386/kernel/setup.c
    --- linux-2.6.10-rc1/arch/i386/kernel/setup.c~i386-lite	2004-10-29 11:26:44.467447425 -0700
    +++ linux-2.6.10-rc1-trini/arch/i386/kernel/setup.c	2004-10-29 11:26:44.484443435 -0700
    @@ -117,6 +117,7 @@ struct e820map e820;
     unsigned char aux_device_present;
     
     extern void early_cpu_init(void);
    +extern void early_trap_init(void);
     extern void dmi_scan_machine(void);
     extern void generic_apic_probe(char *);
     extern int root_mountflags;
    @@ -1302,6 +1303,7 @@ void __init setup_arch(char **cmdline_p)
     	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
     	pre_setup_arch_hook();
     	early_cpu_init();
    +	early_trap_init();
     
     	/*
     	 * FIXME: This isn't an official loader_type right
    @@ -1358,6 +1360,7 @@ void __init setup_arch(char **cmdline_p)
     	data_resource.end = virt_to_phys(_edata)-1;
     
     	parse_cmdline_early(cmdline_p);
    +	parse_early_param();
     
     	max_low_pfn = setup_memory();
     
    diff -puN arch/i386/kernel/signal.c~i386-lite arch/i386/kernel/signal.c
    --- linux-2.6.10-rc1/arch/i386/kernel/signal.c~i386-lite	2004-10-29 11:26:44.469446956 -0700
    +++ linux-2.6.10-rc1-trini/arch/i386/kernel/signal.c	2004-10-29 11:26:44.485443200 -0700
    @@ -600,7 +600,8 @@ int fastcall do_signal(struct pt_regs *r
     		 * 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, &ka, oldset, regs);
    diff -puN arch/i386/kernel/traps.c~i386-lite arch/i386/kernel/traps.c
    --- linux-2.6.10-rc1/arch/i386/kernel/traps.c~i386-lite	2004-10-29 11:26:44.471446486 -0700
    +++ linux-2.6.10-rc1-trini/arch/i386/kernel/traps.c	2004-10-29 11:26:44.486442965 -0700
    @@ -53,6 +53,7 @@
     
     #include <linux/irq.h>
     #include <linux/module.h>
    +#include <linux/debugger.h>
     
     #include "mach_traps.h"
     
    @@ -332,7 +333,7 @@ void die(const char * str, struct pt_reg
     #endif
     		if (nl)
     			printk("\n");
    -	notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
    +		notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
     		show_registers(regs);
       	} else
     		printk(KERN_ERR "Recursive die() failure, output suppressed\n");
    @@ -711,7 +712,7 @@ asmlinkage void do_debug(struct pt_regs 
     	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
    @@ -733,12 +734,14 @@ asmlinkage void do_debug(struct pt_regs 
     	info.si_signo = SIGTRAP;
     	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 __user *)tsk->thread.eip
    -	                                      : (void __user *)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
    @@ -748,6 +751,7 @@ clear_dr7:
     	__asm__("movl %0,%%db7"
     		: /* no output */
     		: "r" (0));
    +	notify_die(DIE_DEBUG, "debug", regs, condition, error_code, SIGTRAP);
     	return;
     
     debug_vm86:
    @@ -1005,6 +1009,12 @@ static void __init set_task_gate(unsigne
     	_set_gate(idt_table+n,5,0,0,(gdt_entry<<3));
     }
     
    +/* Some traps need to be set early. */
    +void __init early_trap_init(void) {
    +	set_intr_gate(1,&debug);
    +	set_system_intr_gate(3, &int3); /* int3 can be called from all */
    +	set_intr_gate(14,&page_fault);
    +}
     
     void __init trap_init(void)
     {
    @@ -1019,10 +1029,8 @@ void __init trap_init(void)
     #endif
     
     	set_trap_gate(0,&divide_error);
    -	set_intr_gate(1,&debug);
     	set_intr_gate(2,&nmi);
    -	set_system_intr_gate(3, &int3); /* int3-5 can be called from all */
    -	set_system_gate(4,&overflow);
    +	set_system_gate(4,&overflow); /* int4/5 can be called from all */
     	set_system_gate(5,&bounds);
     	set_trap_gate(6,&invalid_op);
     	set_trap_gate(7,&device_not_available);
    @@ -1032,7 +1040,6 @@ void __init trap_init(void)
     	set_trap_gate(11,&segment_not_present);
     	set_trap_gate(12,&stack_segment);
     	set_trap_gate(13,&general_protection);
    -	set_intr_gate(14,&page_fault);
     	set_trap_gate(15,&spurious_interrupt_bug);
     	set_trap_gate(16,&coprocessor_error);
     	set_trap_gate(17,&alignment_check);
    diff -puN arch/i386/mm/fault.c~i386-lite arch/i386/mm/fault.c
    --- linux-2.6.10-rc1/arch/i386/mm/fault.c~i386-lite	2004-10-29 11:26:44.473446017 -0700
    +++ linux-2.6.10-rc1-trini/arch/i386/mm/fault.c	2004-10-29 11:26:44.486442965 -0700
    @@ -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>
    @@ -426,6 +432,10 @@ no_context:
      	if (is_prefetch(regs, address, error_code))
      		return;
     
    +	if (notify_die(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
    +				SIGSEGV) == NOTIFY_BAD)
    +		return;
    +
     /*
      * Oops. The kernel tried to access some bad page. We'll have to
      * terminate things with extreme prejudice.
    diff -puN /dev/null include/asm-i386/kgdb.h
    --- /dev/null	2004-10-25 00:35:20.587727328 -0700
    +++ linux-2.6.10-rc1-trini/include/asm-i386/kgdb.h	2004-10-29 11:26:44.487442730 -0700
    @@ -0,0 +1,48 @@
    +#ifndef _ASM_KGDB_H_
    +#define _ASM_KGDB_H_
    +
    +/*
    + * Copyright (C) 2001-2004 Amit S. Kale
    + */
    +
    +#include <linux/ptrace.h>
    +
    +/************************************************************************/
    +/* 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
    +
    +#define CHECK_EXCEPTION_STACK() 	1
    +
    +#endif				/* _ASM_KGDB_H_ */
    diff -puN include/asm-i386/system.h~i386-lite include/asm-i386/system.h
    --- linux-2.6.10-rc1/include/asm-i386/system.h~i386-lite	2004-10-29 11:26:44.476445313 -0700
    +++ linux-2.6.10-rc1-trini/include/asm-i386/system.h	2004-10-29 11:26:44.487442730 -0700
    @@ -12,9 +12,13 @@
     struct task_struct;	/* one of the stranger aspects of C forward declarations.. */
     extern struct task_struct * FASTCALL(__switch_to(struct task_struct *prev, struct task_struct *next));
     
    +/* sleeping_thread_to_gdb_regs depends on this code. Correct it if you change
    + * any of the following */
     #define switch_to(prev,next,last) do {					\
     	unsigned long esi,edi;						\
    -	asm volatile("pushfl\n\t"					\
    +	asm volatile(".globl __switch_to_begin\n"			\
    +		     "__switch_to_begin:"				\
    +		     "pushfl\n\t"					\
     		     "pushl %%ebp\n\t"					\
     		     "movl %%esp,%0\n\t"	/* save ESP */		\
     		     "movl %5,%%esp\n\t"	/* restore ESP */	\
    @@ -23,7 +27,9 @@ extern struct task_struct * FASTCALL(__s
     		     "jmp __switch_to\n"				\
     		     "1:\t"						\
     		     "popl %%ebp\n\t"					\
    -		     "popfl"						\
    +		     "popfl\n"						\
    +		     ".globl __switch_to_end\n"				\
    +		     "__switch_to_end:\n"				\
     		     :"=m" (prev->thread.esp),"=m" (prev->thread.eip),	\
     		      "=a" (last),"=S" (esi),"=D" (edi)			\
     		     :"m" (next->thread.esp),"m" (next->thread.eip),	\
    diff -puN lib/Kconfig.debug~i386-lite lib/Kconfig.debug
    --- linux-2.6.10-rc1/lib/Kconfig.debug~i386-lite	2004-10-29 11:26:44.477445078 -0700
    +++ linux-2.6.10-rc1-trini/lib/Kconfig.debug	2004-10-29 11:32:58.640565630 -0700
    @@ -115,7 +115,7 @@ endif
     
     config KGDB
     	bool "KGDB: kernel debugging with remote gdb"
    -	depends on DEBUG_KERNEL
    +	depends on DEBUG_KERNEL && (X86)
     	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
    _
    -
    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/
    

  • Next message: Tom Rini: "[patch 3/8] KGDB support for ppc32"

    Relevant Pages

    • [patch 2/8] KGDB support for i386
      ... This adds support for KGDB on the i386 architecture. ... +int kgdb_arch_handle_exception(int exceptionVector, int signo, ... +/* Register KGDB with the i386die_chain so that we hook into all of the right ... +extern void early_trap_init; ...
      (Linux-Kernel)
    • [patch 3/3] Add support for X86_64 platforms to KGDB
      ... hooks or changes to x86_64-specific code, as well as the previous kgdb thread. ... +int kgdb_remove_hw_break ... +static struct pt_regs *in_interrupt_stack ... +/* Register KGDB with the die_chain so that we hook into all of the right ...
      (Linux-Kernel)
    • [patch 07/15] Basic x86_64 support
      ... * Origianl kgdb, ... +int kgdb_remove_hw_break ... +static struct pt_regs *in_interrupt_stack ... +/* Register KGDB with the die_chain so that we hook into all of the right ...
      (Linux-Kernel)
    • [patch 08/16] Add support for X86_64 platforms to KGDB
      ... +int kgdb_remove_hw_break ... +static struct pt_regs *in_interrupt_stack ... +/* Register KGDB with the die_chain so that we hook into all of the right ... extern void get_cpu_vendor; ...
      (Linux-Kernel)
    • [PATCH,RFC 2.6.14 02/15] KGDB: i386-specific changes
      ... This adds the basic support for i386. ... KGDB files and Makefile/related is that for support early on we must set some ... +extern void early_trap_init; ... * the register image that Linux produces at interrupt time. ...
      (Linux-Kernel)