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