1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2004 Marcel Moolenaar 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/ctype.h> 35 #include <sys/kdb.h> 36 #include <sys/libkern.h> 37 #include <sys/ttydefaults.h> 38 39 #include <machine/gdb_machdep.h> 40 #include <machine/kdb.h> 41 42 #include <gdb/gdb.h> 43 #include <gdb/gdb_int.h> 44 45 static char gdb_rxbuf[GDB_BUFSZ]; 46 char *gdb_rxp = NULL; 47 size_t gdb_rxsz = 0; 48 static char gdb_txbuf[GDB_BUFSZ]; 49 char *gdb_txp = NULL; /* Used in inline functions. */ 50 51 #define C2N(c) (((c) < 'A') ? (c) - '0' : \ 52 10 + (((c) < 'a') ? (c) - 'A' : (c) - 'a')) 53 #define N2C(n) (((n) < 10) ? (n) + '0' : (n) + 'a' - 10) 54 55 /* 56 * Get a single character 57 */ 58 59 static int 60 gdb_getc(void) 61 { 62 int c; 63 64 do 65 c = gdb_cur->gdb_getc(); 66 while (c == -1); 67 68 if (c == CTRL('C')) { 69 printf("Received ^C; trying to switch back to ddb.\n"); 70 71 if (kdb_dbbe_select("ddb") != 0) 72 printf("The ddb backend could not be selected.\n"); 73 else { 74 printf("using longjmp, hope it works!\n"); 75 kdb_reenter(); 76 } 77 } 78 return (c); 79 } 80 81 /* 82 * Functions to receive and extract from a packet. 83 */ 84 85 int 86 gdb_rx_begin(void) 87 { 88 int c, cksum; 89 90 gdb_rxp = NULL; 91 do { 92 /* 93 * Wait for the start character, ignore all others. 94 * XXX needs a timeout. 95 */ 96 while ((c = gdb_getc()) != '$') 97 ; 98 99 /* Read until a # or end of buffer is found. */ 100 cksum = 0; 101 gdb_rxsz = 0; 102 while (gdb_rxsz < sizeof(gdb_rxbuf) - 1) { 103 c = gdb_getc(); 104 if (c == '#') 105 break; 106 gdb_rxbuf[gdb_rxsz++] = c; 107 cksum += c; 108 } 109 gdb_rxbuf[gdb_rxsz] = 0; 110 cksum &= 0xff; 111 112 /* Bail out on a buffer overflow. */ 113 if (c != '#') { 114 gdb_cur->gdb_putc('-'); 115 return (ENOSPC); 116 } 117 118 c = gdb_getc(); 119 cksum -= (C2N(c) << 4) & 0xf0; 120 c = gdb_getc(); 121 cksum -= C2N(c) & 0x0f; 122 gdb_cur->gdb_putc((cksum == 0) ? '+' : '-'); 123 if (cksum != 0) 124 printf("GDB: packet `%s' has invalid checksum\n", 125 gdb_rxbuf); 126 } while (cksum != 0); 127 128 gdb_rxp = gdb_rxbuf; 129 return (0); 130 } 131 132 int 133 gdb_rx_equal(const char *str) 134 { 135 int len; 136 137 len = strlen(str); 138 if (len > gdb_rxsz || strncmp(str, gdb_rxp, len) != 0) 139 return (0); 140 gdb_rxp += len; 141 gdb_rxsz -= len; 142 return (1); 143 } 144 145 int 146 gdb_rx_mem(unsigned char *addr, size_t size) 147 { 148 unsigned char *p; 149 void *prev; 150 jmp_buf jb; 151 size_t cnt; 152 int ret; 153 unsigned char c; 154 155 if (size * 2 != gdb_rxsz) 156 return (-1); 157 158 prev = kdb_jmpbuf(jb); 159 ret = setjmp(jb); 160 if (ret == 0) { 161 p = addr; 162 cnt = size; 163 while (cnt-- > 0) { 164 c = (C2N(gdb_rxp[0]) << 4) & 0xf0; 165 c |= C2N(gdb_rxp[1]) & 0x0f; 166 *p++ = c; 167 gdb_rxsz -= 2; 168 gdb_rxp += 2; 169 } 170 kdb_cpu_sync_icache(addr, size); 171 } 172 (void)kdb_jmpbuf(prev); 173 return ((ret == 0) ? 1 : 0); 174 } 175 176 int 177 gdb_rx_varhex(uintmax_t *vp) 178 { 179 uintmax_t v; 180 int c, neg; 181 182 c = gdb_rx_char(); 183 neg = (c == '-') ? 1 : 0; 184 if (neg == 1) 185 c = gdb_rx_char(); 186 if (!isxdigit(c)) { 187 gdb_rxp -= ((c == -1) ? 0 : 1) + neg; 188 gdb_rxsz += ((c == -1) ? 0 : 1) + neg; 189 return (-1); 190 } 191 v = 0; 192 do { 193 v <<= 4; 194 v += C2N(c); 195 c = gdb_rx_char(); 196 } while (isxdigit(c)); 197 if (c != -1) { 198 gdb_rxp--; 199 gdb_rxsz++; 200 } 201 *vp = (neg) ? -v : v; 202 return (0); 203 } 204 205 /* 206 * Function to build and send a package. 207 */ 208 209 void 210 gdb_tx_begin(char tp) 211 { 212 213 gdb_txp = gdb_txbuf; 214 if (tp != '\0') 215 gdb_tx_char(tp); 216 } 217 218 int 219 gdb_tx_end(void) 220 { 221 const char *p; 222 int runlen; 223 unsigned char c, cksum; 224 225 do { 226 gdb_cur->gdb_putc('$'); 227 228 cksum = 0; 229 p = gdb_txbuf; 230 while (p < gdb_txp) { 231 /* Send a character and start run-length encoding. */ 232 c = *p++; 233 gdb_cur->gdb_putc(c); 234 cksum += c; 235 runlen = 0; 236 /* Determine run-length and update checksum. */ 237 while (p < gdb_txp && *p == c) { 238 runlen++; 239 p++; 240 } 241 /* Emit the run-length encoded string. */ 242 while (runlen >= 97) { 243 gdb_cur->gdb_putc('*'); 244 cksum += '*'; 245 gdb_cur->gdb_putc(97+29); 246 cksum += 97+29; 247 runlen -= 97; 248 if (runlen > 0) { 249 gdb_cur->gdb_putc(c); 250 cksum += c; 251 runlen--; 252 } 253 } 254 if (runlen == 1) { 255 gdb_cur->gdb_putc(c); 256 cksum += c; 257 runlen--; 258 } 259 if (runlen == 0) 260 continue; 261 /* Don't emit '$', '#', '+' or '-'. */ 262 if (runlen == 7) { 263 gdb_cur->gdb_putc(c); 264 cksum += c; 265 runlen--; 266 } 267 if (runlen == 6 || runlen == 14 || runlen == 16) { 268 gdb_cur->gdb_putc(c); 269 cksum += c; 270 runlen--; 271 } 272 gdb_cur->gdb_putc('*'); 273 cksum += '*'; 274 gdb_cur->gdb_putc(runlen+29); 275 cksum += runlen+29; 276 } 277 278 gdb_cur->gdb_putc('#'); 279 c = cksum >> 4; 280 gdb_cur->gdb_putc(N2C(c)); 281 c = cksum & 0x0f; 282 gdb_cur->gdb_putc(N2C(c)); 283 284 c = gdb_getc(); 285 } while (c != '+'); 286 287 return (0); 288 } 289 290 int 291 gdb_tx_mem(const unsigned char *addr, size_t size) 292 { 293 void *prev; 294 jmp_buf jb; 295 int ret; 296 297 prev = kdb_jmpbuf(jb); 298 ret = setjmp(jb); 299 if (ret == 0) { 300 while (size-- > 0) { 301 *gdb_txp++ = N2C(*addr >> 4); 302 *gdb_txp++ = N2C(*addr & 0x0f); 303 addr++; 304 } 305 } 306 (void)kdb_jmpbuf(prev); 307 return ((ret == 0) ? 1 : 0); 308 } 309 310 void 311 gdb_tx_reg(int regnum) 312 { 313 unsigned char *regp; 314 size_t regsz; 315 316 regp = gdb_cpu_getreg(regnum, ®sz); 317 if (regp == NULL) { 318 /* Register unavailable. */ 319 while (regsz--) { 320 gdb_tx_char('x'); 321 gdb_tx_char('x'); 322 } 323 } else 324 gdb_tx_mem(regp, regsz); 325 } 326 327 /* Read binary data up until the end of the packet or until we have datalen decoded bytes */ 328 int 329 gdb_rx_bindata(unsigned char *data, size_t datalen, size_t *amt) 330 { 331 int c; 332 333 *amt = 0; 334 335 while (*amt < datalen) { 336 c = gdb_rx_char(); 337 /* End of packet? */ 338 if (c == -1) 339 break; 340 /* Escaped character up next */ 341 if (c == '}') { 342 /* Truncated packet? Bail out */ 343 if ((c = gdb_rx_char()) == -1) 344 return (1); 345 c ^= 0x20; 346 } 347 *(data++) = c & 0xff; 348 (*amt)++; 349 } 350 351 return (0); 352 } 353 354 int 355 gdb_search_mem(const unsigned char *addr, size_t size, const unsigned char *pat, size_t patlen, const unsigned char **found) 356 { 357 void *prev; 358 jmp_buf jb; 359 int ret; 360 361 prev = kdb_jmpbuf(jb); 362 ret = setjmp(jb); 363 if (ret == 0) 364 *found = memmem(addr, size, pat, patlen); 365 366 (void)kdb_jmpbuf(prev); 367 return ((ret == 0) ? 1 : 0); 368 } 369