util/log.c

   1 /*
   2  * Logging support
   3  *
   4  *  Copyright (c) 2003 Fabrice Bellard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "qemu/log.h"
  22 #include "qemu/range.h"
  23 #include "qemu/error-report.h"
  24 #include "qapi/error.h"
  25 #include "qemu/cutils.h"
  26 #include "trace/control.h"
  27 #include "qemu/thread.h"
  28
  29 static char *logfilename;
  30 static QemuMutex qemu_logfile_mutex;
  31 QemuLogFile *qemu_logfile;
  32 int qemu_loglevel;
  33 static int log_append = 0;
  34 static GArray *debug_regions;
  35
  36 /* Return the number of characters emitted.  */
  37 int qemu_log(const char *fmt, ...)
  38 {
  39     int ret = 0;
  40     QemuLogFile *logfile;
  41
  42     rcu_read_lock();
  43     logfile = atomic_rcu_read(&qemu_logfile);
  44     if (logfile) {
  45         va_list ap;
  46         va_start(ap, fmt);
  47         ret = vfprintf(logfile->fd, fmt, ap);
  48         va_end(ap);
  49
  50         /* Don't pass back error results.  */
  51         if (ret < 0) {
  52             ret = 0;
  53         }
  54     }
  55     rcu_read_unlock();
  56     return ret;
  57 }
  58
  59 static void __attribute__((__constructor__)) qemu_logfile_init(void)
  60 {
  61     qemu_mutex_init(&qemu_logfile_mutex);
  62 }
  63
  64 static void qemu_logfile_free(QemuLogFile *logfile)
  65 {
  66     g_assert(logfile);
  67
  68     if (logfile->fd != stderr) {
  69         fclose(logfile->fd);
  70     }
  71     g_free(logfile);
  72 }
  73
  74 static bool log_uses_own_buffers;
  75
  76 /* enable or disable low levels log */
  77 void qemu_set_log(int log_flags)
  78 {
  79     bool need_to_open_file = false;
  80     QemuLogFile *logfile;
  81
  82     qemu_loglevel = log_flags;
  83 #ifdef CONFIG_TRACE_LOG
  84     qemu_loglevel |= LOG_TRACE;
  85 #endif
  86     /*
  87      * In all cases we only log if qemu_loglevel is set.
  88      * Also:
  89      *   If not daemonized we will always log either to stderr
  90      *     or to a file (if there is a logfilename).
  91      *   If we are daemonized,
  92      *     we will only log if there is a logfilename.
  93      */
  94     if (qemu_loglevel && (!is_daemonized() || logfilename)) {
  95         need_to_open_file = true;
  96     }
  97     qemu_mutex_lock(&qemu_logfile_mutex);
  98     if (qemu_logfile && !need_to_open_file) {
  99         logfile = qemu_logfile;
 100         atomic_rcu_set(&qemu_logfile, NULL);
 101         call_rcu(logfile, qemu_logfile_free, rcu);
 102     } else if (!qemu_logfile && need_to_open_file) {
 103         logfile = g_new0(QemuLogFile, 1);
 104         if (logfilename) {
 105             logfile->fd = fopen(logfilename, log_append ? "a" : "w");
 106             if (!logfile->fd) {
 107                 g_free(logfile);
 108                 perror(logfilename);
 109                 _exit(1);
 110             }
 111             /* In case we are a daemon redirect stderr to logfile */
 112             if (is_daemonized()) {
 113                 dup2(fileno(logfile->fd), STDERR_FILENO);
 114                 fclose(logfile->fd);
 115                 /* This will skip closing logfile in qemu_log_close() */
 116                 logfile->fd = stderr;
 117             }
 118         } else {
 119             /* Default to stderr if no log file specified */
 120             assert(!is_daemonized());
 121             logfile->fd = stderr;
 122         }
 123         /* must avoid mmap() usage of glibc by setting a buffer "by hand" */
 124         if (log_uses_own_buffers) {
 125             static char logfile_buf[4096];
 126
 127             setvbuf(logfile->fd, logfile_buf, _IOLBF, sizeof(logfile_buf));
 128         } else {
 129 #if defined(_WIN32)
 130             /* Win32 doesn't support line-buffering, so use unbuffered output. */
 131             setvbuf(logfile->fd, NULL, _IONBF, 0);
 132 #else
 133             setvbuf(logfile->fd, NULL, _IOLBF, 0);
 134 #endif
 135             log_append = 1;
 136         }
 137         atomic_rcu_set(&qemu_logfile, logfile);
 138     }
 139     qemu_mutex_unlock(&qemu_logfile_mutex);
 140 }
 141
 142 void qemu_log_needs_buffers(void)
 143 {
 144     log_uses_own_buffers = true;
 145 }
 146
 147 /*
 148  * Allow the user to include %d in their logfile which will be
 149  * substituted with the current PID. This is useful for debugging many
 150  * nested linux-user tasks but will result in lots of logs.
 151  */
 152 void qemu_set_log_filename(const char *filename, Error **errp)
 153 {
 154     char *pidstr;
 155     g_free(logfilename);
 156     logfilename = NULL;
 157
 158     pidstr = strstr(filename, "%");
 159     if (pidstr) {
 160         /* We only accept one %d, no other format strings */
 161         if (pidstr[1] != 'd' || strchr(pidstr + 2, '%')) {
 162             error_setg(errp, "Bad logfile format: %s", filename);
 163             return;
 164         } else {
 165             logfilename = g_strdup_printf(filename, getpid());
 166         }
 167     } else {
 168         logfilename = g_strdup(filename);
 169     }
 170     qemu_log_close();
 171     qemu_set_log(qemu_loglevel);
 172 }
 173
 174 /* Returns true if addr is in our debug filter or no filter defined
 175  */
 176 bool qemu_log_in_addr_range(uint64_t addr)
 177 {
 178     if (debug_regions) {
 179         int i = 0;
 180         for (i = 0; i < debug_regions->len; i++) {
 181             Range *range = &g_array_index(debug_regions, Range, i);
 182             if (range_contains(range, addr)) {
 183                 return true;
 184             }
 185         }
 186         return false;
 187     } else {
 188         return true;
 189     }
 190 }
 191
 192
 193 void qemu_set_dfilter_ranges(const char *filter_spec, Error **errp)
 194 {
 195     gchar **ranges = g_strsplit(filter_spec, ",", 0);
 196     int i;
 197
 198     if (debug_regions) {
 199         g_array_unref(debug_regions);
 200         debug_regions = NULL;
 201     }
 202
 203     debug_regions = g_array_sized_new(FALSE, FALSE,
 204                                       sizeof(Range), g_strv_length(ranges));
 205     for (i = 0; ranges[i]; i++) {
 206         const char *r = ranges[i];
 207         const char *range_op, *r2, *e;
 208         uint64_t r1val, r2val, lob, upb;
 209         struct Range range;
 210
 211         range_op = strstr(r, "-");
 212         r2 = range_op ? range_op + 1 : NULL;
 213         if (!range_op) {
 214             range_op = strstr(r, "+");
 215             r2 = range_op ? range_op + 1 : NULL;
 216         }
 217         if (!range_op) {
 218             range_op = strstr(r, "..");
 219             r2 = range_op ? range_op + 2 : NULL;
 220         }
 221         if (!range_op) {
 222             error_setg(errp, "Bad range specifier");
 223             goto out;
 224         }
 225
 226         if (qemu_strtou64(r, &e, 0, &r1val)
 227             || e != range_op) {
 228             error_setg(errp, "Invalid number to the left of %.*s",
 229                        (int)(r2 - range_op), range_op);
 230             goto out;
 231         }
 232         if (qemu_strtou64(r2, NULL, 0, &r2val)) {
 233             error_setg(errp, "Invalid number to the right of %.*s",
 234                        (int)(r2 - range_op), range_op);
 235             goto out;
 236         }
 237
 238         switch (*range_op) {
 239         case '+':
 240             lob = r1val;
 241             upb = r1val + r2val - 1;
 242             break;
 243         case '-':
 244             upb = r1val;
 245             lob = r1val - (r2val - 1);
 246             break;
 247         case '.':
 248             lob = r1val;
 249             upb = r2val;
 250             break;
 251         default:
 252             g_assert_not_reached();
 253         }
 254         if (lob > upb) {
 255             error_setg(errp, "Invalid range");
 256             goto out;
 257         }
 258         range_set_bounds(&range, lob, upb);
 259         g_array_append_val(debug_regions, range);
 260     }
 261 out:
 262     g_strfreev(ranges);
 263 }
 264
 265 /* fflush() the log file */
 266 void qemu_log_flush(void)
 267 {
 268     QemuLogFile *logfile;
 269
 270     rcu_read_lock();
 271     logfile = atomic_rcu_read(&qemu_logfile);
 272     if (logfile) {
 273         fflush(logfile->fd);
 274     }
 275     rcu_read_unlock();
 276 }
 277
 278 /* Close the log file */
 279 void qemu_log_close(void)
 280 {
 281     QemuLogFile *logfile;
 282
 283     qemu_mutex_lock(&qemu_logfile_mutex);
 284     logfile = qemu_logfile;
 285
 286     if (logfile) {
 287         atomic_rcu_set(&qemu_logfile, NULL);
 288         call_rcu(logfile, qemu_logfile_free, rcu);
 289     }
 290     qemu_mutex_unlock(&qemu_logfile_mutex);
 291 }
 292
 293 const QEMULogItem qemu_log_items[] = {
 294     { CPU_LOG_TB_OUT_ASM, "out_asm",
 295       "show generated host assembly code for each compiled TB" },
 296     { CPU_LOG_TB_IN_ASM, "in_asm",
 297       "show target assembly code for each compiled TB" },
 298     { CPU_LOG_TB_OP, "op",
 299       "show micro ops for each compiled TB" },
 300     { CPU_LOG_TB_OP_OPT, "op_opt",
 301       "show micro ops after optimization" },
 302     { CPU_LOG_TB_OP_IND, "op_ind",
 303       "show micro ops before indirect lowering" },
 304     { CPU_LOG_INT, "int",
 305       "show interrupts/exceptions in short format" },
 306     { CPU_LOG_EXEC, "exec",
 307       "show trace before each executed TB (lots of logs)" },
 308     { CPU_LOG_TB_CPU, "cpu",
 309       "show CPU registers before entering a TB (lots of logs)" },
 310     { CPU_LOG_TB_FPU, "fpu",
 311       "include FPU registers in the 'cpu' logging" },
 312     { CPU_LOG_MMU, "mmu",
 313       "log MMU-related activities" },
 314     { CPU_LOG_PCALL, "pcall",
 315       "x86 only: show protected mode far calls/returns/exceptions" },
 316     { CPU_LOG_RESET, "cpu_reset",
 317       "show CPU state before CPU resets" },
 318     { LOG_UNIMP, "unimp",
 319       "log unimplemented functionality" },
 320     { LOG_GUEST_ERROR, "guest_errors",
 321       "log when the guest OS does something invalid (eg accessing a\n"
 322       "non-existent register)" },
 323     { CPU_LOG_PAGE, "page",
 324       "dump pages at beginning of user mode emulation" },
 325     { CPU_LOG_TB_NOCHAIN, "nochain",
 326       "do not chain compiled TBs so that \"exec\" and \"cpu\" show\n"
 327       "complete traces" },
 328 #ifdef CONFIG_PLUGIN
 329     { CPU_LOG_PLUGIN, "plugin", "output from TCG plugins\n"},
 330 #endif
 331     { 0, NULL, NULL },
 332 };
 333
 334 /* takes a comma separated list of log masks. Return 0 if error. */
 335 int qemu_str_to_log_mask(const char *str)
 336 {
 337     const QEMULogItem *item;
 338     int mask = 0;
 339     char **parts = g_strsplit(str, ",", 0);
 340     char **tmp;
 341
 342     for (tmp = parts; tmp && *tmp; tmp++) {
 343         if (g_str_equal(*tmp, "all")) {
 344             for (item = qemu_log_items; item->mask != 0; item++) {
 345                 mask |= item->mask;
 346             }
 347 #ifdef CONFIG_TRACE_LOG
 348         } else if (g_str_has_prefix(*tmp, "trace:") && (*tmp)[6] != '\0') {
 349             trace_enable_events((*tmp) + 6);
 350             mask |= LOG_TRACE;
 351 #endif
 352         } else {
 353             for (item = qemu_log_items; item->mask != 0; item++) {
 354                 if (g_str_equal(*tmp, item->name)) {
 355                     goto found;
 356                 }
 357             }
 358             goto error;
 359         found:
 360             mask |= item->mask;
 361         }
 362     }
 363
 364     g_strfreev(parts);
 365     return mask;
 366
 367  error:
 368     g_strfreev(parts);
 369     return 0;
 370 }
 371
 372 void qemu_print_log_usage(FILE *f)
 373 {
 374     const QEMULogItem *item;
 375     fprintf(f, "Log items (comma separated):\n");
 376     for (item = qemu_log_items; item->mask != 0; item++) {
 377         fprintf(f, "%-15s %s\n", item->name, item->help);
 378     }
 379 #ifdef CONFIG_TRACE_LOG
 380     fprintf(f, "trace:PATTERN   enable trace events\n");
 381     fprintf(f, "\nUse \"-d trace:help\" to get a list of trace events.\n\n");
 382 #endif
 383 }