1/* 2 * Copyright (c) 2004 Marcel Moolenaar 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: releng/11.0/gnu/usr.bin/gdb/kgdb/trgt_arm.c 298358 2016-04-20 17:58:13Z wma $"); 29 30#include <sys/types.h> 31#ifndef CROSS_DEBUGGER 32#include <machine/pcb.h> 33#include <machine/frame.h> 34#include <machine/armreg.h> 35#endif 36#include <err.h> 37#include <kvm.h> 38#include <string.h> 39 40#include <defs.h> 41#include <target.h> 42#include <gdbthread.h> 43#include <inferior.h> 44#include <regcache.h> 45#include <frame-unwind.h> 46#include <arm-tdep.h> 47 48#include "kgdb.h" 49 50CORE_ADDR 51kgdb_trgt_core_pcb(u_int cpuid) 52{ 53#ifndef CROSS_DEBUGGER 54 return (kgdb_trgt_stop_pcb(cpuid, sizeof(struct pcb))); 55#else 56 return -1; 57#endif 58} 59 60void 61kgdb_trgt_fetch_registers(int regno __unused) 62{ 63#ifndef CROSS_DEBUGGER 64 struct kthr *kt; 65 struct pcb pcb; 66 int i; 67 68 kt = kgdb_thr_lookup_tid(ptid_get_pid(inferior_ptid)); 69 if (kt == NULL) 70 return; 71 if (kvm_read(kvm, kt->pcb, &pcb, sizeof(pcb)) != sizeof(pcb)) { 72 warnx("kvm_read: %s", kvm_geterr(kvm)); 73 memset(&pcb, 0, sizeof(pcb)); 74 } 75 for (i = ARM_A1_REGNUM + 4; i <= ARM_SP_REGNUM; i++) { 76 supply_register(i, (char *)&pcb.pcb_regs.sf_r4 + 77 (i - (ARM_A1_REGNUM + 4 )) * 4); 78 } 79 supply_register(ARM_PC_REGNUM, (char *)&pcb.pcb_regs.sf_pc); 80 supply_register(ARM_LR_REGNUM, (char *)&pcb.pcb_regs.sf_lr); 81#endif 82} 83 84void 85kgdb_trgt_store_registers(int regno __unused) 86{ 87 fprintf_unfiltered(gdb_stderr, "XXX: %s\n", __func__); 88} 89 90void 91kgdb_trgt_new_objfile(struct objfile *objfile) 92{ 93} 94 95#ifndef CROSS_DEBUGGER 96struct kgdb_frame_cache { 97 CORE_ADDR fp; 98 CORE_ADDR sp; 99 CORE_ADDR pc; 100}; 101 102static int kgdb_trgt_frame_offset[26] = { 103 offsetof(struct trapframe, tf_r0), 104 offsetof(struct trapframe, tf_r1), 105 offsetof(struct trapframe, tf_r2), 106 offsetof(struct trapframe, tf_r3), 107 offsetof(struct trapframe, tf_r4), 108 offsetof(struct trapframe, tf_r5), 109 offsetof(struct trapframe, tf_r6), 110 offsetof(struct trapframe, tf_r7), 111 offsetof(struct trapframe, tf_r8), 112 offsetof(struct trapframe, tf_r9), 113 offsetof(struct trapframe, tf_r10), 114 offsetof(struct trapframe, tf_r11), 115 offsetof(struct trapframe, tf_r12), 116 offsetof(struct trapframe, tf_svc_sp), 117 offsetof(struct trapframe, tf_svc_lr), 118 offsetof(struct trapframe, tf_pc), 119 -1, -1, -1, -1, -1, -1, -1, -1, -1, 120 offsetof(struct trapframe, tf_spsr) 121}; 122 123static struct kgdb_frame_cache * 124kgdb_trgt_frame_cache(struct frame_info *next_frame, void **this_cache) 125{ 126 char buf[MAX_REGISTER_SIZE]; 127 struct kgdb_frame_cache *cache; 128 129 cache = *this_cache; 130 if (cache == NULL) { 131 cache = FRAME_OBSTACK_ZALLOC(struct kgdb_frame_cache); 132 *this_cache = cache; 133 frame_unwind_register(next_frame, ARM_SP_REGNUM, buf); 134 cache->sp = extract_unsigned_integer(buf, 135 register_size(current_gdbarch, ARM_SP_REGNUM)); 136 frame_unwind_register(next_frame, ARM_FP_REGNUM, buf); 137 cache->fp = extract_unsigned_integer(buf, 138 register_size(current_gdbarch, ARM_FP_REGNUM)); 139 cache->pc = frame_func_unwind(next_frame); 140 } 141 return (cache); 142} 143 144static int is_undef; 145 146static void 147kgdb_trgt_trapframe_this_id(struct frame_info *next_frame, void **this_cache, 148 struct frame_id *this_id) 149{ 150 struct kgdb_frame_cache *cache; 151 152 cache = kgdb_trgt_frame_cache(next_frame, this_cache); 153 *this_id = frame_id_build(cache->sp, cache->pc); 154} 155 156static void 157kgdb_trgt_trapframe_prev_register(struct frame_info *next_frame, 158 void **this_cache, int regnum, int *optimizedp, enum lval_type *lvalp, 159 CORE_ADDR *addrp, int *realnump, void *valuep) 160{ 161 char dummy_valuep[MAX_REGISTER_SIZE]; 162 struct kgdb_frame_cache *cache; 163 int ofs, regsz; 164 CORE_ADDR sp; 165 166 regsz = register_size(current_gdbarch, regnum); 167 168 if (valuep == NULL) 169 valuep = dummy_valuep; 170 memset(valuep, 0, regsz); 171 *optimizedp = 0; 172 *addrp = 0; 173 *lvalp = not_lval; 174 *realnump = -1; 175 176 ofs = (regnum >= 0 && regnum <= ARM_PS_REGNUM) 177 ? kgdb_trgt_frame_offset[regnum] : -1; 178 if (ofs == -1) 179 return; 180 181 cache = kgdb_trgt_frame_cache(next_frame, this_cache); 182 sp = cache->sp; 183 184 ofs = kgdb_trgt_frame_offset[regnum]; 185 *addrp = sp + ofs; 186 *lvalp = lval_memory; 187 target_read_memory(*addrp, valuep, regsz); 188} 189 190static const struct frame_unwind kgdb_trgt_trapframe_unwind = { 191 UNKNOWN_FRAME, 192 &kgdb_trgt_trapframe_this_id, 193 &kgdb_trgt_trapframe_prev_register 194}; 195#endif 196 197const struct frame_unwind * 198kgdb_trgt_trapframe_sniffer(struct frame_info *next_frame) 199{ 200#ifndef CROSS_DEBUGGER 201 char *pname; 202 CORE_ADDR pc; 203 204 pc = frame_pc_unwind(next_frame); 205 pname = NULL; 206 find_pc_partial_function(pc, &pname, NULL, NULL); 207 if (pname == NULL) { 208 is_undef = 0; 209 return (NULL); 210 } 211 if (!strcmp(pname, "undefinedinstruction")) 212 is_undef = 1; 213 if (strcmp(pname, "Laddress_exception_entry") == 0 || 214 strcmp(pname, "undefined_entry") == 0 || 215 strcmp(pname, "exception_exit") == 0 || 216 strcmp(pname, "Laddress_exception_msg") == 0 || 217 strcmp(pname, "irq_entry") == 0) 218 return (&kgdb_trgt_trapframe_unwind); 219 if (!strcmp(pname, "undefinedinstruction")) 220 is_undef = 1; 221 else 222 is_undef = 0; 223#endif 224 return (NULL); 225} 226 227/* 228 * This function ensures, that the PC is inside the 229 * function section which is understood by GDB. 230 * 231 * Return 0 when fixup is necessary, -1 otherwise. 232 */ 233int 234kgdb_trgt_pc_fixup(CORE_ADDR *pc) 235{ 236#ifndef CROSS_DEBUGGER 237 struct minimal_symbol *msymbol; 238 int valpc; 239 240 /* 241 * exception_exit and swi_exit are special. These functions 242 * are artificially injected into the stack to be executed 243 * as the last entry in calling chain when all functions exit. 244 * Treat them differently. 245 */ 246 msymbol = lookup_minimal_symbol_by_pc(*pc); 247 if (msymbol != NULL) { 248 if (strcmp(DEPRECATED_SYMBOL_NAME(msymbol), "exception_exit") == 0) 249 return (0); 250 if (strcmp(DEPRECATED_SYMBOL_NAME(msymbol), "swi_exit") == 0) 251 return (0); 252 } 253 254 /* 255 * kdb_enter contains an invalid instruction which is supposed 256 * to generate a trap. BFD does not understand it and treats 257 * this part of function as a separate function. Move PC 258 * two instruction earlier to be inside kdb_enter section. 259 */ 260 target_read_memory(*pc - 4, (char*)&valpc, 4); 261 if (valpc == 0xe7ffffff) { 262 *pc = *pc - 8; 263 return (0); 264 } 265 266 /* 267 * When the panic/vpanic is the last (noreturn) function, 268 * the bottom of the calling function looks as below. 269 * mov lr, pc 270 * b panic 271 * Normally, GDB is not able to detect function boundaries, 272 * so move the PC two instruction earlier where it can deal 273 * with it. 274 * Match this pair of instructions: mov lr, pc followed with 275 * non-linked branch. 276 */ 277 if ((valpc & 0xff000000) == 0xea000000) { 278 target_read_memory(*pc - 8, (char*)&valpc, 4); 279 if (valpc == 0xe1a0e00f) { 280 *pc -= 8; 281 return (0); 282 } 283 } 284#endif 285 return (-1); 286} 287