424 lines
12 KiB
C
424 lines
12 KiB
C
/*
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* Originally written by Glenn Engel, Lake Stevens Instrument Division
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*
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* Contributed by HP Systems
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*
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* Modified for Linux/MIPS (and MIPS in general) by Andreas Busse
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* Send complaints, suggestions etc. to <andy@waldorf-gmbh.de>
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*
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* Copyright (C) 1995 Andreas Busse
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*
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* Copyright (C) 2003 MontaVista Software Inc.
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* Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
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*
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* Copyright (C) 2004-2005 MontaVista Software Inc.
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* Author: Manish Lachwani, mlachwani@mvista.com or manish@koffee-break.com
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*
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* Copyright (C) 2007-2008 Wind River Systems, Inc.
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* Author/Maintainer: Jason Wessel, jason.wessel@windriver.com
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*
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* This file is licensed under the terms of the GNU General Public License
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* version 2. This program is licensed "as is" without any warranty of any
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* kind, whether express or implied.
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*/
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#include <linux/ptrace.h> /* for linux pt_regs struct */
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#include <linux/kgdb.h>
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#include <linux/kdebug.h>
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#include <linux/sched.h>
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#include <linux/smp.h>
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#include <asm/inst.h>
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#include <asm/fpu.h>
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#include <asm/cacheflush.h>
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#include <asm/processor.h>
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#include <asm/sigcontext.h>
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#include <linux/uaccess.h>
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static struct hard_trap_info {
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unsigned char tt; /* Trap type code for MIPS R3xxx and R4xxx */
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unsigned char signo; /* Signal that we map this trap into */
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} hard_trap_info[] = {
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{ 6, SIGBUS }, /* instruction bus error */
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{ 7, SIGBUS }, /* data bus error */
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{ 9, SIGTRAP }, /* break */
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/* { 11, SIGILL }, */ /* CPU unusable */
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{ 12, SIGFPE }, /* overflow */
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{ 13, SIGTRAP }, /* trap */
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{ 14, SIGSEGV }, /* virtual instruction cache coherency */
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{ 15, SIGFPE }, /* floating point exception */
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{ 23, SIGSEGV }, /* watch */
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{ 31, SIGSEGV }, /* virtual data cache coherency */
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{ 0, 0} /* Must be last */
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};
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struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
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{
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{ "zero", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[0]) },
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{ "at", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[1]) },
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{ "v0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[2]) },
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{ "v1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[3]) },
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{ "a0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[4]) },
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{ "a1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[5]) },
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{ "a2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[6]) },
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{ "a3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[7]) },
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{ "t0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[8]) },
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{ "t1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[9]) },
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{ "t2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[10]) },
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{ "t3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[11]) },
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{ "t4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[12]) },
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{ "t5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[13]) },
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{ "t6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[14]) },
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{ "t7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[15]) },
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{ "s0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[16]) },
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{ "s1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[17]) },
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{ "s2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[18]) },
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{ "s3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[19]) },
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{ "s4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[20]) },
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{ "s5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[21]) },
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{ "s6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[22]) },
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{ "s7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[23]) },
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{ "t8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[24]) },
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{ "t9", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[25]) },
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{ "k0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[26]) },
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{ "k1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[27]) },
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{ "gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[28]) },
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{ "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[29]) },
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{ "s8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[30]) },
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{ "ra", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[31]) },
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{ "sr", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_status) },
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{ "lo", GDB_SIZEOF_REG, offsetof(struct pt_regs, lo) },
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{ "hi", GDB_SIZEOF_REG, offsetof(struct pt_regs, hi) },
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{ "bad", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_badvaddr) },
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{ "cause", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_cause) },
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{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_epc) },
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{ "f0", GDB_SIZEOF_REG, 0 },
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{ "f1", GDB_SIZEOF_REG, 1 },
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{ "f2", GDB_SIZEOF_REG, 2 },
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{ "f3", GDB_SIZEOF_REG, 3 },
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{ "f4", GDB_SIZEOF_REG, 4 },
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{ "f5", GDB_SIZEOF_REG, 5 },
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{ "f6", GDB_SIZEOF_REG, 6 },
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{ "f7", GDB_SIZEOF_REG, 7 },
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{ "f8", GDB_SIZEOF_REG, 8 },
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{ "f9", GDB_SIZEOF_REG, 9 },
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{ "f10", GDB_SIZEOF_REG, 10 },
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{ "f11", GDB_SIZEOF_REG, 11 },
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{ "f12", GDB_SIZEOF_REG, 12 },
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{ "f13", GDB_SIZEOF_REG, 13 },
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{ "f14", GDB_SIZEOF_REG, 14 },
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{ "f15", GDB_SIZEOF_REG, 15 },
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{ "f16", GDB_SIZEOF_REG, 16 },
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{ "f17", GDB_SIZEOF_REG, 17 },
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{ "f18", GDB_SIZEOF_REG, 18 },
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{ "f19", GDB_SIZEOF_REG, 19 },
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{ "f20", GDB_SIZEOF_REG, 20 },
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{ "f21", GDB_SIZEOF_REG, 21 },
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{ "f22", GDB_SIZEOF_REG, 22 },
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{ "f23", GDB_SIZEOF_REG, 23 },
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{ "f24", GDB_SIZEOF_REG, 24 },
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{ "f25", GDB_SIZEOF_REG, 25 },
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{ "f26", GDB_SIZEOF_REG, 26 },
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{ "f27", GDB_SIZEOF_REG, 27 },
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{ "f28", GDB_SIZEOF_REG, 28 },
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{ "f29", GDB_SIZEOF_REG, 29 },
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{ "f30", GDB_SIZEOF_REG, 30 },
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{ "f31", GDB_SIZEOF_REG, 31 },
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{ "fsr", GDB_SIZEOF_REG, 0 },
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{ "fir", GDB_SIZEOF_REG, 0 },
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};
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int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
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{
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int fp_reg;
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if (regno < 0 || regno >= DBG_MAX_REG_NUM)
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return -EINVAL;
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if (dbg_reg_def[regno].offset != -1 && regno < 38) {
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memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
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dbg_reg_def[regno].size);
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} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
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/* FP registers 38 -> 69 */
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if (!(regs->cp0_status & ST0_CU1))
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return 0;
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if (regno == 70) {
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/* Process the fcr31/fsr (register 70) */
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memcpy((void *)¤t->thread.fpu.fcr31, mem,
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dbg_reg_def[regno].size);
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goto out_save;
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} else if (regno == 71) {
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/* Ignore the fir (register 71) */
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goto out_save;
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}
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fp_reg = dbg_reg_def[regno].offset;
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memcpy((void *)¤t->thread.fpu.fpr[fp_reg], mem,
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dbg_reg_def[regno].size);
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out_save:
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restore_fp(current);
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}
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return 0;
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}
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char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
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{
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int fp_reg;
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if (regno >= DBG_MAX_REG_NUM || regno < 0)
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return NULL;
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if (dbg_reg_def[regno].offset != -1 && regno < 38) {
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/* First 38 registers */
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memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
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dbg_reg_def[regno].size);
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} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
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/* FP registers 38 -> 69 */
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if (!(regs->cp0_status & ST0_CU1))
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goto out;
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save_fp(current);
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if (regno == 70) {
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/* Process the fcr31/fsr (register 70) */
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memcpy(mem, (void *)¤t->thread.fpu.fcr31,
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dbg_reg_def[regno].size);
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goto out;
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} else if (regno == 71) {
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/* Ignore the fir (register 71) */
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memset(mem, 0, dbg_reg_def[regno].size);
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goto out;
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}
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fp_reg = dbg_reg_def[regno].offset;
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memcpy(mem, (void *)¤t->thread.fpu.fpr[fp_reg],
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dbg_reg_def[regno].size);
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}
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out:
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return dbg_reg_def[regno].name;
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}
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void arch_kgdb_breakpoint(void)
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{
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__asm__ __volatile__(
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".globl breakinst\n\t"
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".set\tnoreorder\n\t"
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"nop\n"
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"breakinst:\tbreak\n\t"
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"nop\n\t"
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".set\treorder");
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}
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static void kgdb_call_nmi_hook(void *ignored)
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{
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mm_segment_t old_fs;
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old_fs = get_fs();
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set_fs(get_ds());
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kgdb_nmicallback(raw_smp_processor_id(), NULL);
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set_fs(old_fs);
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}
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void kgdb_roundup_cpus(unsigned long flags)
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{
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local_irq_enable();
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smp_call_function(kgdb_call_nmi_hook, NULL, 0);
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local_irq_disable();
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}
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static int compute_signal(int tt)
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{
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struct hard_trap_info *ht;
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for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
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if (ht->tt == tt)
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return ht->signo;
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return SIGHUP; /* default for things we don't know about */
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}
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/*
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* Similar to regs_to_gdb_regs() except that process is sleeping and so
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* we may not be able to get all the info.
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*/
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void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
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{
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int reg;
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#if (KGDB_GDB_REG_SIZE == 32)
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u32 *ptr = (u32 *)gdb_regs;
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#else
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u64 *ptr = (u64 *)gdb_regs;
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#endif
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for (reg = 0; reg < 16; reg++)
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*(ptr++) = 0;
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/* S0 - S7 */
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*(ptr++) = p->thread.reg16;
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*(ptr++) = p->thread.reg17;
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*(ptr++) = p->thread.reg18;
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*(ptr++) = p->thread.reg19;
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*(ptr++) = p->thread.reg20;
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*(ptr++) = p->thread.reg21;
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*(ptr++) = p->thread.reg22;
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*(ptr++) = p->thread.reg23;
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for (reg = 24; reg < 28; reg++)
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*(ptr++) = 0;
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/* GP, SP, FP, RA */
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*(ptr++) = (long)p;
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*(ptr++) = p->thread.reg29;
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*(ptr++) = p->thread.reg30;
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*(ptr++) = p->thread.reg31;
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*(ptr++) = p->thread.cp0_status;
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/* lo, hi */
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*(ptr++) = 0;
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*(ptr++) = 0;
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/*
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* BadVAddr, Cause
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* Ideally these would come from the last exception frame up the stack
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* but that requires unwinding, otherwise we can't know much for sure.
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*/
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*(ptr++) = 0;
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*(ptr++) = 0;
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/*
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* PC
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* use return address (RA), i.e. the moment after return from resume()
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*/
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*(ptr++) = p->thread.reg31;
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}
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void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
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{
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regs->cp0_epc = pc;
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}
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/*
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* Calls linux_debug_hook before the kernel dies. If KGDB is enabled,
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* then try to fall into the debugger
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*/
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static int kgdb_mips_notify(struct notifier_block *self, unsigned long cmd,
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void *ptr)
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{
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struct die_args *args = (struct die_args *)ptr;
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struct pt_regs *regs = args->regs;
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int trap = (regs->cp0_cause & 0x7c) >> 2;
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mm_segment_t old_fs;
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#ifdef CONFIG_KPROBES
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/*
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* Return immediately if the kprobes fault notifier has set
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* DIE_PAGE_FAULT.
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*/
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if (cmd == DIE_PAGE_FAULT)
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return NOTIFY_DONE;
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#endif /* CONFIG_KPROBES */
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/* Userspace events, ignore. */
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if (user_mode(regs))
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return NOTIFY_DONE;
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/* Kernel mode. Set correct address limit */
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old_fs = get_fs();
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set_fs(get_ds());
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if (atomic_read(&kgdb_active) != -1)
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kgdb_nmicallback(smp_processor_id(), regs);
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if (kgdb_handle_exception(trap, compute_signal(trap), cmd, regs)) {
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set_fs(old_fs);
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return NOTIFY_DONE;
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}
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if (atomic_read(&kgdb_setting_breakpoint))
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if ((trap == 9) && (regs->cp0_epc == (unsigned long)breakinst))
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regs->cp0_epc += 4;
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/* In SMP mode, __flush_cache_all does IPI */
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local_irq_enable();
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__flush_cache_all();
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set_fs(old_fs);
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return NOTIFY_STOP;
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}
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#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
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int kgdb_ll_trap(int cmd, const char *str,
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struct pt_regs *regs, long err, int trap, int sig)
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{
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struct die_args args = {
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.regs = regs,
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.str = str,
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.err = err,
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.trapnr = trap,
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.signr = sig,
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};
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if (!kgdb_io_module_registered)
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return NOTIFY_DONE;
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return kgdb_mips_notify(NULL, cmd, &args);
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}
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#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
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static struct notifier_block kgdb_notifier = {
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.notifier_call = kgdb_mips_notify,
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};
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/*
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* Handle the 'c' command
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*/
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int kgdb_arch_handle_exception(int vector, int signo, int err_code,
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char *remcom_in_buffer, char *remcom_out_buffer,
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struct pt_regs *regs)
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{
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char *ptr;
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unsigned long address;
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switch (remcom_in_buffer[0]) {
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case 'c':
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/* handle the optional parameter */
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ptr = &remcom_in_buffer[1];
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if (kgdb_hex2long(&ptr, &address))
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regs->cp0_epc = address;
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return 0;
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}
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return -1;
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}
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struct kgdb_arch arch_kgdb_ops;
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int kgdb_arch_init(void)
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{
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union mips_instruction insn = {
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.r_format = {
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.opcode = spec_op,
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.func = break_op,
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}
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};
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memcpy(arch_kgdb_ops.gdb_bpt_instr, insn.byte, BREAK_INSTR_SIZE);
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register_die_notifier(&kgdb_notifier);
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return 0;
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}
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/*
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* kgdb_arch_exit - Perform any architecture specific uninitalization.
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*
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* This function will handle the uninitalization of any architecture
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* specific callbacks, for dynamic registration and unregistration.
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*/
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void kgdb_arch_exit(void)
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{
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unregister_die_notifier(&kgdb_notifier);
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}
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