gdbstub/user-target.c

   1 /*
   2  * Target specific user-mode handling
   3  *
   4  * Copyright (c) 2003-2005 Fabrice Bellard
   5  * Copyright (c) 2022 Linaro Ltd
   6  *
   7  * SPDX-License-Identifier: LGPL-2.0+
   8  */
   9
  10 #include "qemu/osdep.h"
  11 #include "exec/gdbstub.h"
  12 #include "qemu.h"
  13 #include "internals.h"
  14 #ifdef CONFIG_LINUX
  15 #include "linux-user/loader.h"
  16 #include "linux-user/qemu.h"
  17 #endif
  18
  19 /*
  20  * Map target signal numbers to GDB protocol signal numbers and vice
  21  * versa.  For user emulation's currently supported systems, we can
  22  * assume most signals are defined.
  23  */
  24
  25 static int gdb_signal_table[] = {
  26     0,
  27     TARGET_SIGHUP,
  28     TARGET_SIGINT,
  29     TARGET_SIGQUIT,
  30     TARGET_SIGILL,
  31     TARGET_SIGTRAP,
  32     TARGET_SIGABRT,
  33     -1, /* SIGEMT */
  34     TARGET_SIGFPE,
  35     TARGET_SIGKILL,
  36     TARGET_SIGBUS,
  37     TARGET_SIGSEGV,
  38     TARGET_SIGSYS,
  39     TARGET_SIGPIPE,
  40     TARGET_SIGALRM,
  41     TARGET_SIGTERM,
  42     TARGET_SIGURG,
  43     TARGET_SIGSTOP,
  44     TARGET_SIGTSTP,
  45     TARGET_SIGCONT,
  46     TARGET_SIGCHLD,
  47     TARGET_SIGTTIN,
  48     TARGET_SIGTTOU,
  49     TARGET_SIGIO,
  50     TARGET_SIGXCPU,
  51     TARGET_SIGXFSZ,
  52     TARGET_SIGVTALRM,
  53     TARGET_SIGPROF,
  54     TARGET_SIGWINCH,
  55     -1, /* SIGLOST */
  56     TARGET_SIGUSR1,
  57     TARGET_SIGUSR2,
  58 #ifdef TARGET_SIGPWR
  59     TARGET_SIGPWR,
  60 #else
  61     -1,
  62 #endif
  63     -1, /* SIGPOLL */
  64     -1,
  65     -1,
  66     -1,
  67     -1,
  68     -1,
  69     -1,
  70     -1,
  71     -1,
  72     -1,
  73     -1,
  74     -1,
  75 #ifdef __SIGRTMIN
  76     __SIGRTMIN + 1,
  77     __SIGRTMIN + 2,
  78     __SIGRTMIN + 3,
  79     __SIGRTMIN + 4,
  80     __SIGRTMIN + 5,
  81     __SIGRTMIN + 6,
  82     __SIGRTMIN + 7,
  83     __SIGRTMIN + 8,
  84     __SIGRTMIN + 9,
  85     __SIGRTMIN + 10,
  86     __SIGRTMIN + 11,
  87     __SIGRTMIN + 12,
  88     __SIGRTMIN + 13,
  89     __SIGRTMIN + 14,
  90     __SIGRTMIN + 15,
  91     __SIGRTMIN + 16,
  92     __SIGRTMIN + 17,
  93     __SIGRTMIN + 18,
  94     __SIGRTMIN + 19,
  95     __SIGRTMIN + 20,
  96     __SIGRTMIN + 21,
  97     __SIGRTMIN + 22,
  98     __SIGRTMIN + 23,
  99     __SIGRTMIN + 24,
 100     __SIGRTMIN + 25,
 101     __SIGRTMIN + 26,
 102     __SIGRTMIN + 27,
 103     __SIGRTMIN + 28,
 104     __SIGRTMIN + 29,
 105     __SIGRTMIN + 30,
 106     __SIGRTMIN + 31,
 107     -1, /* SIGCANCEL */
 108     __SIGRTMIN,
 109     __SIGRTMIN + 32,
 110     __SIGRTMIN + 33,
 111     __SIGRTMIN + 34,
 112     __SIGRTMIN + 35,
 113     __SIGRTMIN + 36,
 114     __SIGRTMIN + 37,
 115     __SIGRTMIN + 38,
 116     __SIGRTMIN + 39,
 117     __SIGRTMIN + 40,
 118     __SIGRTMIN + 41,
 119     __SIGRTMIN + 42,
 120     __SIGRTMIN + 43,
 121     __SIGRTMIN + 44,
 122     __SIGRTMIN + 45,
 123     __SIGRTMIN + 46,
 124     __SIGRTMIN + 47,
 125     __SIGRTMIN + 48,
 126     __SIGRTMIN + 49,
 127     __SIGRTMIN + 50,
 128     __SIGRTMIN + 51,
 129     __SIGRTMIN + 52,
 130     __SIGRTMIN + 53,
 131     __SIGRTMIN + 54,
 132     __SIGRTMIN + 55,
 133     __SIGRTMIN + 56,
 134     __SIGRTMIN + 57,
 135     __SIGRTMIN + 58,
 136     __SIGRTMIN + 59,
 137     __SIGRTMIN + 60,
 138     __SIGRTMIN + 61,
 139     __SIGRTMIN + 62,
 140     __SIGRTMIN + 63,
 141     __SIGRTMIN + 64,
 142     __SIGRTMIN + 65,
 143     __SIGRTMIN + 66,
 144     __SIGRTMIN + 67,
 145     __SIGRTMIN + 68,
 146     __SIGRTMIN + 69,
 147     __SIGRTMIN + 70,
 148     __SIGRTMIN + 71,
 149     __SIGRTMIN + 72,
 150     __SIGRTMIN + 73,
 151     __SIGRTMIN + 74,
 152     __SIGRTMIN + 75,
 153     __SIGRTMIN + 76,
 154     __SIGRTMIN + 77,
 155     __SIGRTMIN + 78,
 156     __SIGRTMIN + 79,
 157     __SIGRTMIN + 80,
 158     __SIGRTMIN + 81,
 159     __SIGRTMIN + 82,
 160     __SIGRTMIN + 83,
 161     __SIGRTMIN + 84,
 162     __SIGRTMIN + 85,
 163     __SIGRTMIN + 86,
 164     __SIGRTMIN + 87,
 165     __SIGRTMIN + 88,
 166     __SIGRTMIN + 89,
 167     __SIGRTMIN + 90,
 168     __SIGRTMIN + 91,
 169     __SIGRTMIN + 92,
 170     __SIGRTMIN + 93,
 171     __SIGRTMIN + 94,
 172     __SIGRTMIN + 95,
 173     -1, /* SIGINFO */
 174     -1, /* UNKNOWN */
 175     -1, /* DEFAULT */
 176     -1,
 177     -1,
 178     -1,
 179     -1,
 180     -1,
 181     -1
 182 #endif
 183 };
 184
 185 int gdb_signal_to_target(int sig)
 186 {
 187     if (sig < ARRAY_SIZE(gdb_signal_table)) {
 188         return gdb_signal_table[sig];
 189     } else {
 190         return -1;
 191     }
 192 }
 193
 194 int gdb_target_signal_to_gdb(int sig)
 195 {
 196     int i;
 197     for (i = 0; i < ARRAY_SIZE(gdb_signal_table); i++) {
 198         if (gdb_signal_table[i] == sig) {
 199             return i;
 200         }
 201     }
 202     return GDB_SIGNAL_UNKNOWN;
 203 }
 204
 205 int gdb_get_cpu_index(CPUState *cpu)
 206 {
 207     TaskState *ts = get_task_state(cpu);
 208     return ts ? ts->ts_tid : -1;
 209 }
 210
 211 /*
 212  * User-mode specific command helpers
 213  */
 214
 215 void gdb_handle_query_offsets(GArray *params, void *user_ctx)
 216 {
 217     TaskState *ts;
 218
 219     ts = gdbserver_state.c_cpu->opaque;
 220     g_string_printf(gdbserver_state.str_buf,
 221                     "Text=" TARGET_ABI_FMT_lx
 222                     ";Data=" TARGET_ABI_FMT_lx
 223                     ";Bss=" TARGET_ABI_FMT_lx,
 224                     ts->info->code_offset,
 225                     ts->info->data_offset,
 226                     ts->info->data_offset);
 227     gdb_put_strbuf();
 228 }
 229
 230 #if defined(CONFIG_LINUX)
 231 /* Partial user only duplicate of helper in gdbstub.c */
 232 static inline int target_memory_rw_debug(CPUState *cpu, target_ulong addr,
 233                                          uint8_t *buf, int len, bool is_write)
 234 {
 235     CPUClass *cc;
 236     cc = CPU_GET_CLASS(cpu);
 237     if (cc->memory_rw_debug) {
 238         return cc->memory_rw_debug(cpu, addr, buf, len, is_write);
 239     }
 240     return cpu_memory_rw_debug(cpu, addr, buf, len, is_write);
 241 }
 242
 243 void gdb_handle_query_xfer_auxv(GArray *params, void *user_ctx)
 244 {
 245     TaskState *ts;
 246     unsigned long offset, len, saved_auxv, auxv_len;
 247
 248     if (params->len < 2) {
 249         gdb_put_packet("E22");
 250         return;
 251     }
 252
 253     offset = get_param(params, 0)->val_ul;
 254     len = get_param(params, 1)->val_ul;
 255     ts = gdbserver_state.c_cpu->opaque;
 256     saved_auxv = ts->info->saved_auxv;
 257     auxv_len = ts->info->auxv_len;
 258
 259     if (offset >= auxv_len) {
 260         gdb_put_packet("E00");
 261         return;
 262     }
 263
 264     if (len > (MAX_PACKET_LENGTH - 5) / 2) {
 265         len = (MAX_PACKET_LENGTH - 5) / 2;
 266     }
 267
 268     if (len < auxv_len - offset) {
 269         g_string_assign(gdbserver_state.str_buf, "m");
 270     } else {
 271         g_string_assign(gdbserver_state.str_buf, "l");
 272         len = auxv_len - offset;
 273     }
 274
 275     g_byte_array_set_size(gdbserver_state.mem_buf, len);
 276     if (target_memory_rw_debug(gdbserver_state.g_cpu, saved_auxv + offset,
 277                                gdbserver_state.mem_buf->data, len, false)) {
 278         gdb_put_packet("E14");
 279         return;
 280     }
 281
 282     gdb_memtox(gdbserver_state.str_buf,
 283            (const char *)gdbserver_state.mem_buf->data, len);
 284     gdb_put_packet_binary(gdbserver_state.str_buf->str,
 285                       gdbserver_state.str_buf->len, true);
 286 }
 287 #endif
 288
 289 static const char *get_filename_param(GArray *params, int i)
 290 {
 291     const char *hex_filename = get_param(params, i)->data;
 292     gdb_hextomem(gdbserver_state.mem_buf, hex_filename,
 293                  strlen(hex_filename) / 2);
 294     g_byte_array_append(gdbserver_state.mem_buf, (const guint8 *)"", 1);
 295     return (const char *)gdbserver_state.mem_buf->data;
 296 }
 297
 298 static void hostio_reply_with_data(const void *buf, size_t n)
 299 {
 300     g_string_printf(gdbserver_state.str_buf, "F%zx;", n);
 301     gdb_memtox(gdbserver_state.str_buf, buf, n);
 302     gdb_put_packet_binary(gdbserver_state.str_buf->str,
 303                           gdbserver_state.str_buf->len, true);
 304 }
 305
 306 void gdb_handle_v_file_open(GArray *params, void *user_ctx)
 307 {
 308     const char *filename = get_filename_param(params, 0);
 309     uint64_t flags = get_param(params, 1)->val_ull;
 310     uint64_t mode = get_param(params, 2)->val_ull;
 311
 312 #ifdef CONFIG_LINUX
 313     int fd = do_guest_openat(cpu_env(gdbserver_state.g_cpu), 0, filename,
 314                              flags, mode, false);
 315 #else
 316     int fd = open(filename, flags, mode);
 317 #endif
 318     if (fd < 0) {
 319         g_string_printf(gdbserver_state.str_buf, "F-1,%d", errno);
 320     } else {
 321         g_string_printf(gdbserver_state.str_buf, "F%d", fd);
 322     }
 323     gdb_put_strbuf();
 324 }
 325
 326 void gdb_handle_v_file_close(GArray *params, void *user_ctx)
 327 {
 328     int fd = get_param(params, 0)->val_ul;
 329
 330     if (close(fd) == -1) {
 331         g_string_printf(gdbserver_state.str_buf, "F-1,%d", errno);
 332         gdb_put_strbuf();
 333         return;
 334     }
 335
 336     gdb_put_packet("F00");
 337 }
 338
 339 void gdb_handle_v_file_pread(GArray *params, void *user_ctx)
 340 {
 341     int fd = get_param(params, 0)->val_ul;
 342     size_t count = get_param(params, 1)->val_ull;
 343     off_t offset = get_param(params, 2)->val_ull;
 344
 345     size_t bufsiz = MIN(count, BUFSIZ);
 346     g_autofree char *buf = g_try_malloc(bufsiz);
 347     if (buf == NULL) {
 348         gdb_put_packet("E12");
 349         return;
 350     }
 351
 352     ssize_t n = pread(fd, buf, bufsiz, offset);
 353     if (n < 0) {
 354         g_string_printf(gdbserver_state.str_buf, "F-1,%d", errno);
 355         gdb_put_strbuf();
 356         return;
 357     }
 358     hostio_reply_with_data(buf, n);
 359 }
 360
 361 void gdb_handle_v_file_readlink(GArray *params, void *user_ctx)
 362 {
 363     const char *filename = get_filename_param(params, 0);
 364
 365     g_autofree char *buf = g_try_malloc(BUFSIZ);
 366     if (buf == NULL) {
 367         gdb_put_packet("E12");
 368         return;
 369     }
 370
 371 #ifdef CONFIG_LINUX
 372     ssize_t n = do_guest_readlink(filename, buf, BUFSIZ);
 373 #else
 374     ssize_t n = readlink(filename, buf, BUFSIZ);
 375 #endif
 376     if (n < 0) {
 377         g_string_printf(gdbserver_state.str_buf, "F-1,%d", errno);
 378         gdb_put_strbuf();
 379         return;
 380     }
 381     hostio_reply_with_data(buf, n);
 382 }
 383
 384 void gdb_handle_query_xfer_exec_file(GArray *params, void *user_ctx)
 385 {
 386     uint32_t pid = get_param(params, 0)->val_ul;
 387     uint32_t offset = get_param(params, 1)->val_ul;
 388     uint32_t length = get_param(params, 2)->val_ul;
 389
 390     GDBProcess *process = gdb_get_process(pid);
 391     if (!process) {
 392         gdb_put_packet("E00");
 393         return;
 394     }
 395
 396     CPUState *cpu = gdb_get_first_cpu_in_process(process);
 397     if (!cpu) {
 398         gdb_put_packet("E00");
 399         return;
 400     }
 401
 402     TaskState *ts = get_task_state(cpu);
 403     if (!ts || !ts->bprm || !ts->bprm->filename) {
 404         gdb_put_packet("E00");
 405         return;
 406     }
 407
 408     size_t total_length = strlen(ts->bprm->filename);
 409     if (offset > total_length) {
 410         gdb_put_packet("E00");
 411         return;
 412     }
 413     if (offset + length > total_length) {
 414         length = total_length - offset;
 415     }
 416
 417     g_string_printf(gdbserver_state.str_buf, "l%.*s", length,
 418                     ts->bprm->filename + offset);
 419     gdb_put_strbuf();
 420 }
 421
 422 int gdb_target_sigtrap(void)
 423 {
 424     return TARGET_SIGTRAP;
 425 }