Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751156AbVKJQmz (ORCPT ); Thu, 10 Nov 2005 11:42:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751154AbVKJQmz (ORCPT ); Thu, 10 Nov 2005 11:42:55 -0500 Received: from fed1rmmtao12.cox.net ([68.230.241.27]:30640 "EHLO fed1rmmtao12.cox.net") by vger.kernel.org with ESMTP id S1751152AbVKJQmx (ORCPT ); Thu, 10 Nov 2005 11:42:53 -0500 From: Tom Rini To: Andrew Morton Cc: Tom Rini , lkml Message-Id: <20051110164245.20950.33549.sendpatchset@localhost.localdomain> In-Reply-To: <20051110163906.20950.45704.sendpatchset@localhost.localdomain> References: <20051110163906.20950.45704.sendpatchset@localhost.localdomain> Subject: [PATCH,RFC 2.6.14 08/15] KGDB: x86_64-specific changes Date: Thu, 10 Nov 2005 11:41:49 -0500 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 20945 Lines: 722 This adds support for the x86_64 architecture. In addition to what was noted in the core-lite patch about stuff outside of new files, we add -g0 to compiling of syscalls.o as otherwise we run into problems when debugging modules, and like i386 annotate switch_to(). arch/x86_64/Kconfig.debug | 3 arch/x86_64/kernel/Makefile | 1 arch/x86_64/kernel/kgdb-jmp.S | 65 +++++ arch/x86_64/kernel/kgdb.c | 460 ++++++++++++++++++++++++++++++++++++++++++ include/asm-x86_64/kgdb.h | 50 ++++ include/asm-x86_64/system.h | 6 include/linux/kgdb.h | 4 kernel/kgdb.c | 14 + lib/Kconfig.debug | 2 9 files changed, 599 insertions(+), 6 deletions(-) Index: linux-2.6.14/arch/x86_64/Kconfig.debug =================================================================== --- linux-2.6.14.orig/arch/x86_64/Kconfig.debug +++ linux-2.6.14/arch/x86_64/Kconfig.debug @@ -51,7 +51,4 @@ config IOMMU_LEAK Add a simple leak tracer to the IOMMU code. This is useful when you are debugging a buggy device driver that leaks IOMMU mappings. -#config X86_REMOTE_DEBUG -# bool "kgdb debugging stub" - endmenu Index: linux-2.6.14/arch/x86_64/kernel/kgdb.c =================================================================== --- /dev/null +++ linux-2.6.14/arch/x86_64/kernel/kgdb.c @@ -0,0 +1,460 @@ +/* + * + * 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) 2004 Amit S. Kale + * Copyright (C) 2000-2001 VERITAS Software Corporation. + * Copyright (C) 2002 Andi Kleen, SuSE Labs + * Copyright (C) 2004 LinSysSoft Technologies Pvt. Ltd. + */ +/**************************************************************************** + * Contributor: Lake Stevens Instrument Division$ + * Written by: Glenn Engel $ + * Updated by: Amit Kale + * 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 + * X86_64 changes from Andi Kleen's patch merged by Jim Houston + */ + +#include +#include +#include +#include +#include +#include +#include +#include /* for linux pt_regs struct */ +#include +#include +#include +#include +#include +#include + +/* Put the error code here just in case the user cares. */ +int gdb_x86_64errcode; +/* Likewise, the vector number here (since GDB only gets the signal + number through the usual means, and that's not very specific). */ +int gdb_x86_64vector = -1; + +extern atomic_t cpu_doing_single_step; + +void regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) +{ + gdb_regs[_RAX] = regs->rax; + gdb_regs[_RBX] = regs->rbx; + gdb_regs[_RCX] = regs->rcx; + gdb_regs[_RDX] = regs->rdx; + gdb_regs[_RSI] = regs->rsi; + gdb_regs[_RDI] = regs->rdi; + gdb_regs[_RBP] = regs->rbp; + gdb_regs[_PS] = regs->eflags; + gdb_regs[_PC] = regs->rip; + gdb_regs[_R8] = regs->r8; + gdb_regs[_R9] = regs->r9; + gdb_regs[_R10] = regs->r10; + gdb_regs[_R11] = regs->r11; + gdb_regs[_R12] = regs->r12; + gdb_regs[_R13] = regs->r13; + gdb_regs[_R14] = regs->r14; + gdb_regs[_R15] = regs->r15; + gdb_regs[_RSP] = regs->rsp; +} + +extern void thread_return(void); +void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) +{ + gdb_regs[_RAX] = 0; + gdb_regs[_RBX] = 0; + gdb_regs[_RCX] = 0; + gdb_regs[_RDX] = 0; + gdb_regs[_RSI] = 0; + gdb_regs[_RDI] = 0; + gdb_regs[_RBP] = *(unsigned long *)p->thread.rsp; + gdb_regs[_PS] = *(unsigned long *)(p->thread.rsp + 8); + gdb_regs[_PC] = (unsigned long)&thread_return; + gdb_regs[_R8] = 0; + gdb_regs[_R9] = 0; + gdb_regs[_R10] = 0; + gdb_regs[_R11] = 0; + gdb_regs[_R12] = 0; + gdb_regs[_R13] = 0; + gdb_regs[_R14] = 0; + gdb_regs[_R15] = 0; + gdb_regs[_RSP] = p->thread.rsp; +} + +void gdb_regs_to_regs(unsigned long *gdb_regs, struct pt_regs *regs) +{ + regs->rax = gdb_regs[_RAX]; + regs->rbx = gdb_regs[_RBX]; + regs->rcx = gdb_regs[_RCX]; + regs->rdx = gdb_regs[_RDX]; + regs->rsi = gdb_regs[_RSI]; + regs->rdi = gdb_regs[_RDI]; + regs->rbp = gdb_regs[_RBP]; + regs->eflags = gdb_regs[_PS]; + regs->rip = gdb_regs[_PC]; + regs->r8 = gdb_regs[_R8]; + regs->r9 = gdb_regs[_R9]; + regs->r10 = gdb_regs[_R10]; + regs->r11 = gdb_regs[_R11]; + regs->r12 = gdb_regs[_R12]; + regs->r13 = gdb_regs[_R13]; + regs->r14 = gdb_regs[_R14]; + regs->r15 = gdb_regs[_R15]; +#if 0 /* can't change these */ + regs->rsp = gdb_regs[_RSP]; + regs->ss = gdb_regs[_SS]; + regs->fs = gdb_regs[_FS]; + regs->gs = gdb_regs[_GS]; +#endif + +} /* gdb_regs_to_regs */ + +struct hw_breakpoint { + unsigned enabled; + unsigned type; + unsigned len; + unsigned long addr; +} breakinfo[4] = { { +enabled:0}, { +enabled:0}, { +enabled:0}, { +enabled:0}}; + +void kgdb_correct_hw_break(void) +{ + int breakno; + int correctit; + int breakbit; + unsigned long dr7; + + asm volatile ("movq %%db7, %0\n":"=r" (dr7):); + do { + unsigned long addr0, addr1, addr2, addr3; + asm volatile ("movq %%db0, %0\n" + "movq %%db1, %1\n" + "movq %%db2, %2\n" + "movq %%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 ("movq %0, %%dr0\n"::"r" + (breakinfo[breakno].addr)); + break; + + case 1: + asm volatile ("movq %0, %%dr1\n"::"r" + (breakinfo[breakno].addr)); + break; + + case 2: + asm volatile ("movq %0, %%dr2\n"::"r" + (breakinfo[breakno].addr)); + break; + + case 3: + asm volatile ("movq %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 ("movq %0, %%db7\n"::"r" (dr7)); + } +} + +int kgdb_remove_hw_break(unsigned long addr) +{ + 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 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 = 1; + 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_disable_hw_debug(struct pt_regs *regs) +{ + /* Disable hardware debugging while we are in kgdb */ + asm volatile ("movq %0,%%db7": /* no output */ :"r" (0UL)); +} + +void kgdb_post_master_code(struct pt_regs *regs, int e_vector, int err_code) +{ + /* Master processor is completely in the debugger */ + gdb_x86_64vector = e_vector; + gdb_x86_64errcode = err_code; +} + +void kgdb_roundup_cpus(unsigned long flags) +{ + send_IPI_allbutself(APIC_DM_NMI); +} + +int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, + char *remcomInBuffer, char *remcomOutBuffer, + struct pt_regs *linux_regs) +{ + unsigned long addr, length; + unsigned long breakno, breaktype; + char *ptr; + int newPC; + unsigned long dr6; + + switch (remcomInBuffer[0]) { + case 'c': + case 's': + /* try to read optional parameter, pc unchanged if no parm */ + ptr = &remcomInBuffer[1]; + if (kgdb_hex2long(&ptr, &addr)) + linux_regs->rip = addr; + newPC = linux_regs->rip; + + /* 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 (remcomInBuffer[0] == 's') { + linux_regs->eflags |= TF_MASK; + debugger_step = 1; + if (kgdb_contthread) + atomic_set(&cpu_doing_single_step, + smp_processor_id()); + + } + + asm volatile ("movq %%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 ("movq %0, %%db6\n"::"r" (0UL)); + + 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; +} + +static struct pt_regs *in_interrupt_stack(unsigned long rsp, int cpu) +{ + struct pt_regs *regs; + unsigned long end = (unsigned long)cpu_pda[cpu].irqstackptr; + if (rsp <= end && rsp >= end - IRQSTACKSIZE + 8) { + regs = *(((struct pt_regs **)end) - 1); + return regs; + } + return NULL; +} + +static struct pt_regs *in_exception_stack(unsigned long rsp, int cpu) +{ + int i; + struct tss_struct *init_tss = &__get_cpu_var(init_tss); + for (i = 0; i < N_EXCEPTION_STACKS; i++) + if (rsp >= init_tss[cpu].ist[i] && + rsp <= init_tss[cpu].ist[i] + EXCEPTION_STKSZ) { + struct pt_regs *r = + (void *)init_tss[cpu].ist[i] + EXCEPTION_STKSZ; + return r - 1; + } + return NULL; +} + +void kgdb_shadowinfo(struct pt_regs *regs, char *buffer, unsigned threadid) +{ + static char intr_desc[] = "Stack at interrupt entrypoint"; + static char exc_desc[] = "Stack at exception entrypoint"; + struct pt_regs *stregs; + int cpu = hard_smp_processor_id(); + + if ((stregs = in_interrupt_stack(regs->rsp, cpu))) + kgdb_mem2hex(intr_desc, buffer, strlen(intr_desc)); + else if ((stregs = in_exception_stack(regs->rsp, cpu))) + kgdb_mem2hex(exc_desc, buffer, strlen(exc_desc)); +} + +struct task_struct *kgdb_get_shadow_thread(struct pt_regs *regs, int threadid) +{ + struct pt_regs *stregs; + int cpu = hard_smp_processor_id(); + + if ((stregs = in_interrupt_stack(regs->rsp, cpu))) + return current; + else if ((stregs = in_exception_stack(regs->rsp, cpu))) + return current; + + return NULL; +} + +struct pt_regs *kgdb_shadow_regs(struct pt_regs *regs, int threadid) +{ + struct pt_regs *stregs; + int cpu = hard_smp_processor_id(); + + if ((stregs = in_interrupt_stack(regs->rsp, cpu))) + return stregs; + else if ((stregs = in_exception_stack(regs->rsp, cpu))) + return stregs; + + return NULL; +} + +/* Register KGDB with the die_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 = ptr; + struct pt_regs *regs = args->regs; + + if (cmd == DIE_PAGE_FAULT_NO_CONTEXT && atomic_read(&debugger_active) + && kgdb_may_fault) { + kgdb_fault_longjmp(kgdb_fault_jmp_regs); + return NOTIFY_STOP; + /* CPU roundup? */ + } else if (atomic_read(&debugger_active) && cmd == DIE_NMI_IPI) { + kgdb_nmihook(smp_processor_id(), regs); + return NOTIFY_STOP; + /* See if KGDB is interested. */ + } else if (cmd == DIE_PAGE_FAULT || user_mode(regs) || + cmd == DIE_NMI_IPI || (cmd == DIE_DEBUG && + atomic_read(&debugger_active))) + /* Userpace events, normal watchdog event, or spurious + * debug exception. Ignore. */ + return NOTIFY_DONE; + + kgdb_handle_exception(args->trapnr, args->signr, args->err, regs); + + return NOTIFY_STOP; +} + +static struct notifier_block kgdb_notifier = { + .notifier_call = kgdb_notify, + .priority = 0x7fffffff, /* we need to notified first */ +}; + +int kgdb_arch_init(void) +{ + notifier_chain_register(&die_chain, &kgdb_notifier); + return 0; +} + +struct kgdb_arch arch_kgdb_ops = { + .gdb_bpt_instr = {0xcc}, + .flags = KGDB_HW_BREAKPOINT, + .shadowth = 1, +}; Index: linux-2.6.14/arch/x86_64/kernel/kgdb-jmp.S =================================================================== --- /dev/null +++ linux-2.6.14/arch/x86_64/kernel/kgdb-jmp.S @@ -0,0 +1,65 @@ +/* + * arch/x86_64/kernel/kgdb-jmp.S + * + * Save and restore system registers so that within a limited frame we + * may have a fault and "jump back" to a known safe location. + * + * Author: Tom Rini + * + * Cribbed from glibc, which carries the following: + * Copyright (C) 2001, 2003, 2004 Free Software Foundation, Inc. + * Copyright (C) 2005 by MontaVista Software. + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program as licensed "as is" without any warranty of + * any kind, whether express or implied. + */ + +#include + +#define JB_RBX 0 +#define JB_RBP 1 +#define JB_R12 2 +#define JB_R13 3 +#define JB_R14 4 +#define JB_R15 5 +#define JB_RSP 6 +#define JB_PC 7 + + .code64 + +/* This must be called prior to kgdb_fault_longjmp and + * kgdb_fault_longjmp must not be called outside of the context of the + * last call to kgdb_fault_setjmp. + */ +ENTRY(kgdb_fault_setjmp) + /* Save registers. */ + movq %rbx, (JB_RBX*8)(%rdi) + movq %rbp, (JB_RBP*8)(%rdi) + movq %r12, (JB_R12*8)(%rdi) + movq %r13, (JB_R13*8)(%rdi) + movq %r14, (JB_R14*8)(%rdi) + movq %r15, (JB_R15*8)(%rdi) + leaq 8(%rsp), %rdx /* Save SP as it will be after we return. */ + movq %rdx, (JB_RSP*8)(%rdi) + movq (%rsp), %rax /* Save PC we are returning to now. */ + movq %rax, (JB_PC*8)(%rdi) + /* Set return value for setjmp. */ + mov $0,%eax + movq (JB_PC*8)(%rdi),%rdx + movq (JB_RSP*8)(%rdi),%rsp + jmpq *%rdx + +ENTRY(kgdb_fault_longjmp) + /* Restore registers. */ + movq (JB_RBX*8)(%rdi),%rbx + movq (JB_RBP*8)(%rdi),%rbp + movq (JB_R12*8)(%rdi),%r12 + movq (JB_R13*8)(%rdi),%r13 + movq (JB_R14*8)(%rdi),%r14 + movq (JB_R15*8)(%rdi),%r15 + /* Set return value for setjmp. */ + movq (JB_PC*8)(%rdi),%rdx + movq (JB_RSP*8)(%rdi),%rsp + mov $1,%eax + jmpq *%rdx Index: linux-2.6.14/arch/x86_64/kernel/Makefile =================================================================== --- linux-2.6.14.orig/arch/x86_64/kernel/Makefile +++ linux-2.6.14/arch/x86_64/kernel/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_GART_IOMMU) += pci-gart.o a obj-$(CONFIG_DUMMY_IOMMU) += pci-nommu.o pci-dma.o obj-$(CONFIG_SWIOTLB) += swiotlb.o obj-$(CONFIG_KPROBES) += kprobes.o +obj-$(CONFIG_KGDB) += kgdb.o kgdb-jmp.o obj-$(CONFIG_X86_PM_TIMER) += pmtimer.o obj-$(CONFIG_MODULES) += module.o Index: linux-2.6.14/include/asm-x86_64/kgdb.h =================================================================== --- /dev/null +++ linux-2.6.14/include/asm-x86_64/kgdb.h @@ -0,0 +1,50 @@ +#ifdef __KERNEL__ +#ifndef _ASM_KGDB_H_ +#define _ASM_KGDB_H_ + +/* + * Copyright (C) 2001-2004 Amit S. Kale + */ + +/* + * 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. + */ +#define _RAX 0 +#define _RDX 1 +#define _RCX 2 +#define _RBX 3 +#define _RSI 4 +#define _RDI 5 +#define _RBP 6 +#define _RSP 7 +#define _R8 8 +#define _R9 9 +#define _R10 10 +#define _R11 11 +#define _R12 12 +#define _R13 13 +#define _R14 14 +#define _R15 15 +#define _PC 16 +#define _PS 17 + +/* Number of bytes of registers. */ +#define NUMREGBYTES ((_PS+1)*8) +#define NUMCRITREGBYTES (8 * 8) /* 8 registers. */ + +#ifndef __ASSEMBLY__ +/* BUFMAX defines the maximum number of characters in inbound/outbound + * buffers at least NUMREGBYTES*2 are needed for register packets, and + * a longer buffer is needed to list all threads. */ +#define BUFMAX 1024 +#define BREAKPOINT() asm(" int $3"); +#define CHECK_EXCEPTION_STACK() ((&__get_cpu_var(init_tss))[0].ist[0]) +#define BREAK_INSTR_SIZE 1 +#define CACHE_FLUSH_IS_SAFE 1 +#endif /* !__ASSEMBLY__ */ +#endif /* _ASM_KGDB_H_ */ +#endif /* __KERNEL__ */ Index: linux-2.6.14/include/asm-x86_64/system.h =================================================================== --- linux-2.6.14.orig/include/asm-x86_64/system.h +++ linux-2.6.14/include/asm-x86_64/system.h @@ -27,7 +27,9 @@ ,"rcx","rbx","rdx","r8","r9","r10","r11","r12","r13","r14","r15" #define switch_to(prev,next,last) \ - asm volatile(SAVE_CONTEXT \ + asm volatile(".globl __switch_to_begin\n\t" \ + "__switch_to_begin:\n\t" \ + SAVE_CONTEXT \ "movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \ "movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */ \ "call __switch_to\n\t" \ @@ -39,6 +41,8 @@ "movq %%rax,%%rdi\n\t" \ "jc ret_from_fork\n\t" \ RESTORE_CONTEXT \ + ".globl __switch_to_end\n\t" \ + "__switch_to_end:\n\t" \ : "=a" (last) \ : [next] "S" (next), [prev] "D" (prev), \ [threadrsp] "i" (offsetof(struct task_struct, thread.rsp)), \ Index: linux-2.6.14/lib/Kconfig.debug =================================================================== --- linux-2.6.14.orig/lib/Kconfig.debug +++ linux-2.6.14/lib/Kconfig.debug @@ -187,7 +187,7 @@ config WANT_EXTRA_DEBUG_INFORMATION config KGDB bool "KGDB: kernel debugging with remote gdb" select WANT_EXTRA_DEBUG_INFORMATION - depends on DEBUG_KERNEL && (X86 || MIPS || IA64 || ((!SMP || BROKEN) && PPC32)) + depends on DEBUG_KERNEL && (X86 || MIPS || IA64 || X86_64 || ((!SMP || BROKEN) && PPC32)) help If you say Y here, it will be possible to remotely debug the kernel using gdb. It is strongly suggested that you enable Index: linux-2.6.14/include/linux/kgdb.h =================================================================== --- linux-2.6.14.orig/include/linux/kgdb.h +++ linux-2.6.14/include/linux/kgdb.h @@ -24,6 +24,10 @@ #include #include +#ifndef CHECK_EXCEPTION_STACK +#define CHECK_EXCEPTION_STACK() 1 +#endif + struct tasklet_struct; struct pt_regs; struct task_struct; Index: linux-2.6.14/kernel/kgdb.c =================================================================== --- linux-2.6.14.orig/kernel/kgdb.c +++ linux-2.6.14/kernel/kgdb.c @@ -1629,7 +1629,8 @@ void kgdb_unregister_io_module(struct kg */ static void kgdb_tasklet_bpt(unsigned long ing) { - breakpoint(); + if(CHECK_EXCEPTION_STACK()) + breakpoint(); } DECLARE_TASKLET(kgdb_tasklet_breakpoint, kgdb_tasklet_bpt, 0); @@ -1640,6 +1641,17 @@ DECLARE_TASKLET(kgdb_tasklet_breakpoint, */ static void __init kgdb_early_entry(void) { + /* + * Don't try and do anything until the architecture is able to + * setup the exception stack. In this case, it is up to the + * architecture to hook in and look at us when they are ready. + */ + if(!CHECK_EXCEPTION_STACK()) { + kgdb_initialized = -1; + tasklet_schedule(&kgdb_tasklet_breakpoint); + return; + } + /* Let the architecture do any setup that it needs to. */ kgdb_arch_init(); -- Tom - 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/