1/* $NetBSD: kgdb_machdep.c,v 1.22 2023/10/25 06:02:14 skrll Exp $ */ 2 3/*- 4 * Copyright (c) 1997 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33/* 34 * Copyright (c) 1996 Matthias Pfaller. 35 * All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 46 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 47 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 48 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 49 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 50 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 51 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 52 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 53 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 54 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 55 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 56 */ 57 58#include <sys/cdefs.h> 59__KERNEL_RCSID(0, "$NetBSD: kgdb_machdep.c,v 1.22 2023/10/25 06:02:14 skrll Exp $"); 60 61#include "opt_ddb.h" 62 63#if defined(DDB) 64#error "Can't build DDB and KGDB together." 65#endif 66 67/* 68 * Machine-dependent functions for remote KGDB. Originally written 69 * for NetBSD/pc532 by Matthias Pfaller. Modified for NetBSD/i386 70 * by Jason R. Thorpe. Modified for NetBSD/mips by Ethan Solomita 71 */ 72 73#include "opt_cputype.h" /* which mips CPUs do we support? */ 74 75#include <sys/types.h> 76#include <sys/systm.h> 77#include <sys/param.h> 78#include <sys/proc.h> 79#include <sys/reboot.h> 80#include <sys/kgdb.h> 81 82#include <uvm/uvm_extern.h> 83 84#include <mips/locore.h> 85#include <mips/pte.h> 86#include <mips/cpu.h> 87#include <mips/mips_opcode.h> 88#include <mips/reg.h> 89#include <mips/trap.h> 90#include <dev/cons.h> 91 92#include <machine/db_machdep.h> 93#include <ddb/db_access.h> 94 95/* 96 * Is kva a valid address to access? This is used by KGDB. 97 */ 98static int 99kvacc(vaddr_t kva) 100{ 101 if (pmap_md_direct_mapped_vaddr_p(kva)) 102 return 1; 103 104 if (kva < VM_MIN_KERNEL_ADDRESS || kva >= VM_MAX_KERNEL_ADDRESS) 105 return 0; 106 107 const pt_entry_t * const ptep = pmap_pte_lookup(pmap_kernel(), kva); 108 return ptep != NULL && pte_valid_p(*ptep); 109} 110 111/* 112 * Determine if the memory at va..(va+len) is valid. 113 */ 114int 115kgdb_acc(vaddr_t va, size_t len) 116{ 117 vaddr_t last_va; 118 119 last_va = va + len + PAGE_SIZE - 1; 120 va &= ~PGOFSET; 121 last_va &= ~PGOFSET; 122 123 for (; va < last_va; va += PAGE_SIZE) { 124 if (kvacc(va) == 0) 125 return 0; 126 } 127 128 return (1); 129} 130 131/* 132 * Translate a trap number into a unix compatible signal value. 133 * (gdb only understands unix signal numbers). 134 */ 135int 136kgdb_signal(int type) 137{ 138 switch (type) { 139 case T_TLB_MOD: 140 case T_TLB_MOD+T_USER: 141 case T_TLB_LD_MISS: 142 case T_TLB_ST_MISS: 143 case T_TLB_LD_MISS+T_USER: 144 case T_TLB_ST_MISS+T_USER: 145 case T_ADDR_ERR_LD: /* misaligned access */ 146 case T_ADDR_ERR_ST: /* misaligned access */ 147 case T_BUS_ERR_LD_ST: /* BERR asserted to CPU */ 148 case T_ADDR_ERR_LD+T_USER: /* misaligned or kseg access */ 149 case T_ADDR_ERR_ST+T_USER: /* misaligned or kseg access */ 150 case T_BUS_ERR_IFETCH+T_USER: /* BERR asserted to CPU */ 151 case T_BUS_ERR_LD_ST+T_USER: /* BERR asserted to CPU */ 152 return (SIGSEGV); 153 154 case T_BREAK: 155 case T_BREAK+T_USER: 156 return (SIGTRAP); 157 158 case T_RES_INST+T_USER: 159 case T_COP_UNUSABLE+T_USER: 160 return (SIGILL); 161 162 case T_FPE+T_USER: 163 case T_OVFLOW+T_USER: 164 return (SIGFPE); 165 166 default: 167 return (SIGEMT); 168 } 169} 170 171mips_reg_t kgdb_cause, kgdb_vaddr; /* set by trap() */ 172 173/* 174 * Translate the values stored in the db_regs_t struct to the format 175 * understood by gdb. 176 */ 177void 178kgdb_getregs(db_regs_t *regs, kgdb_reg_t *gdb_regs) 179{ 180 memset(gdb_regs, 0, KGDB_NUMREGS * sizeof(kgdb_reg_t)); 181 gdb_regs[ 1] = regs->r_regs[_R_AST]; /* AT */ 182 gdb_regs[ 2] = regs->r_regs[_R_V0]; /* V0 */ 183 gdb_regs[ 3] = regs->r_regs[_R_V1]; /* V1 */ 184 gdb_regs[ 4] = regs->r_regs[_R_A0]; /* A0 */ 185 gdb_regs[ 5] = regs->r_regs[_R_A1]; /* A1 */ 186 gdb_regs[ 6] = regs->r_regs[_R_A2]; /* A2 */ 187 gdb_regs[ 7] = regs->r_regs[_R_A3]; /* A3 */ 188#if defined(__mips_n32) || defined(__mips_n64) 189 gdb_regs[ 8] = regs->r_regs[_R_A4]; /* A4 */ 190 gdb_regs[ 9] = regs->r_regs[_R_A5]; /* A5 */ 191 gdb_regs[10] = regs->r_regs[_R_A6]; /* A6 */ 192 gdb_regs[11] = regs->r_regs[_R_A7]; /* A7 */ 193 gdb_regs[12] = regs->r_regs[_R_T0]; /* T0 */ 194 gdb_regs[13] = regs->r_regs[_R_T1]; /* T1 */ 195 gdb_regs[14] = regs->r_regs[_R_T2]; /* T2 */ 196 gdb_regs[15] = regs->r_regs[_R_T3]; /* T3 */ 197#else 198 gdb_regs[ 8] = regs->r_regs[_R_T0]; /* T0 */ 199 gdb_regs[ 9] = regs->r_regs[_R_T1]; /* T1 */ 200 gdb_regs[10] = regs->r_regs[_R_T2]; /* T2 */ 201 gdb_regs[11] = regs->r_regs[_R_T3]; /* T3 */ 202 gdb_regs[12] = regs->r_regs[_R_T4]; /* T4 */ 203 gdb_regs[13] = regs->r_regs[_R_T5]; /* T5 */ 204 gdb_regs[14] = regs->r_regs[_R_T6]; /* T6 */ 205 gdb_regs[15] = regs->r_regs[_R_T7]; /* T7 */ 206#endif /* __mips_n32 || __mips_n64 */ 207 gdb_regs[16] = regs->r_regs[_R_S0]; /* S0 */ 208 gdb_regs[17] = regs->r_regs[_R_S1]; /* S1 */ 209 gdb_regs[18] = regs->r_regs[_R_S2]; /* S2 */ 210 gdb_regs[19] = regs->r_regs[_R_S3]; /* S3 */ 211 gdb_regs[20] = regs->r_regs[_R_S4]; /* S4 */ 212 gdb_regs[21] = regs->r_regs[_R_S5]; /* S5 */ 213 gdb_regs[22] = regs->r_regs[_R_S6]; /* S6 */ 214 gdb_regs[23] = regs->r_regs[_R_S7]; /* S7 */ 215 gdb_regs[24] = regs->r_regs[_R_T8]; /* T8 */ 216 gdb_regs[25] = regs->r_regs[_R_T9]; /* T9 */ 217 gdb_regs[28] = regs->r_regs[_R_GP]; /* GP */ 218 gdb_regs[29] = regs->r_regs[_R_SP]; /* SP */ 219 gdb_regs[30] = regs->r_regs[_R_S8]; /* S8 */ 220 gdb_regs[31] = regs->r_regs[_R_RA]; /* RA */ 221 gdb_regs[32] = regs->r_regs[_R_SR]; /* SR */ 222 gdb_regs[33] = regs->r_regs[_R_MULLO]; /* MULLO */ 223 gdb_regs[34] = regs->r_regs[_R_MULHI]; /* MULHI */ 224 gdb_regs[35] = kgdb_vaddr; /* BAD VADDR */ 225 gdb_regs[36] = kgdb_cause; /* CAUSE */ 226 gdb_regs[37] = regs->r_regs[_R_PC]; /* PC */ 227} 228 229/* 230 * Reverse the above. 231 */ 232void 233kgdb_setregs(db_regs_t *regs, kgdb_reg_t *gdb_regs) 234{ 235 regs->r_regs[_R_PC] = gdb_regs[37]; /* PC */ 236} 237 238/* 239 * Trap into kgdb to wait for debugger to connect, 240 * noting on the console why nothing else is going on. 241 */ 242void 243kgdb_connect(int verbose) 244{ 245 if (kgdb_dev < 0) 246 return; 247 248 if (verbose) 249 printf("kgdb waiting..."); 250 251 __asm("break"); 252 253 if (verbose) 254 printf("connected.\n"); 255 256 kgdb_debug_panic = 1; 257} 258 259/* 260 * Decide what to do on panic. 261 * (This is called by panic, like Debugger()) 262 */ 263void 264kgdb_panic(void) 265{ 266 if (kgdb_dev != NODEV && kgdb_debug_panic) { 267 printf("entering kgdb\n"); 268 kgdb_connect(kgdb_active == 0); 269 } 270} 271