util/log.c - third_party/qemu - Git at Google

 /*
  * Logging support
  *
  *  Copyright (c) 2003 Fabrice Bellard
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  */

 #include "qemu/osdep.h"
 #include "qemu/log.h"
 #include "qemu/range.h"
 #include "qemu/error-report.h"
 #include "qapi/error.h"
 #include "qemu/cutils.h"
 #include "trace/control.h"
 #include "qemu/thread.h"

 static char *logfilename;
 static QemuMutex qemu_logfile_mutex;
 QemuLogFile *qemu_logfile;
 int qemu_loglevel;
 static int log_append = 0;
 static GArray *debug_regions;

 /* Return the number of characters emitted.  */
 int qemu_log(const char *fmt, ...)
 {
     int ret = 0;
     QemuLogFile *logfile;

     rcu_read_lock();
     logfile = atomic_rcu_read(&qemu_logfile);
     if (logfile) {
         va_list ap;
         va_start(ap, fmt);
         ret = vfprintf(logfile->fd, fmt, ap);
         va_end(ap);

         /* Don't pass back error results.  */
         if (ret < 0) {
             ret = 0;
         }
     }
     rcu_read_unlock();
     return ret;
 }

 static void __attribute__((__constructor__)) qemu_logfile_init(void)
 {
     qemu_mutex_init(&qemu_logfile_mutex);
 }

 static void qemu_logfile_free(QemuLogFile *logfile)
 {
     g_assert(logfile);

     if (logfile->fd != stderr) {
         fclose(logfile->fd);
     }
     g_free(logfile);
 }

 static bool log_uses_own_buffers;

 /* enable or disable low levels log */
 void qemu_set_log(int log_flags)
 {
     bool need_to_open_file = false;
     QemuLogFile *logfile;

     qemu_loglevel = log_flags;
 #ifdef CONFIG_TRACE_LOG
     qemu_loglevel |= LOG_TRACE;
 #endif
     /*
      * In all cases we only log if qemu_loglevel is set.
      * Also:
      *   If not daemonized we will always log either to stderr
      *     or to a file (if there is a logfilename).
      *   If we are daemonized,
      *     we will only log if there is a logfilename.
      */
     if (qemu_loglevel && (!is_daemonized() || logfilename)) {
         need_to_open_file = true;
     }
     qemu_mutex_lock(&qemu_logfile_mutex);
     if (qemu_logfile && !need_to_open_file) {
         logfile = qemu_logfile;
         atomic_rcu_set(&qemu_logfile, NULL);
         call_rcu(logfile, qemu_logfile_free, rcu);
     } else if (!qemu_logfile && need_to_open_file) {
         logfile = g_new0(QemuLogFile, 1);
         if (logfilename) {
             logfile->fd = fopen(logfilename, log_append ? "a" : "w");
             if (!logfile->fd) {
                 g_free(logfile);
                 perror(logfilename);
                 _exit(1);
             }
             /* In case we are a daemon redirect stderr to logfile */
             if (is_daemonized()) {
                 dup2(fileno(logfile->fd), STDERR_FILENO);
                 fclose(logfile->fd);
                 /* This will skip closing logfile in qemu_log_close() */
                 logfile->fd = stderr;
             }
         } else {
             /* Default to stderr if no log file specified */
             assert(!is_daemonized());
             logfile->fd = stderr;
         }
         /* must avoid mmap() usage of glibc by setting a buffer "by hand" */
         if (log_uses_own_buffers) {
             static char logfile_buf[4096];

             setvbuf(logfile->fd, logfile_buf, _IOLBF, sizeof(logfile_buf));
         } else {
 #if defined(_WIN32)
             /* Win32 doesn't support line-buffering, so use unbuffered output. */
             setvbuf(logfile->fd, NULL, _IONBF, 0);
 #else
             setvbuf(logfile->fd, NULL, _IOLBF, 0);
 #endif
             log_append = 1;
         }
         atomic_rcu_set(&qemu_logfile, logfile);
     }
     qemu_mutex_unlock(&qemu_logfile_mutex);
 }

 void qemu_log_needs_buffers(void)
 {
     log_uses_own_buffers = true;
 }

 /*
  * Allow the user to include %d in their logfile which will be
  * substituted with the current PID. This is useful for debugging many
  * nested linux-user tasks but will result in lots of logs.
  *
  * filename may be NULL. In that case, log output is sent to stderr
  */
 void qemu_set_log_filename(const char *filename, Error **errp)
 {
     g_free(logfilename);
     logfilename = NULL;

     if (filename) {
             char *pidstr = strstr(filename, "%");
             if (pidstr) {
                 /* We only accept one %d, no other format strings */
                 if (pidstr[1] != 'd' || strchr(pidstr + 2, '%')) {
                     error_setg(errp, "Bad logfile format: %s", filename);
                     return;
                 } else {
                     logfilename = g_strdup_printf(filename, getpid());
                 }
             } else {
                 logfilename = g_strdup(filename);
             }
     }

     qemu_log_close();
     qemu_set_log(qemu_loglevel);
 }

 /* Returns true if addr is in our debug filter or no filter defined
  */
 bool qemu_log_in_addr_range(uint64_t addr)
 {
     if (debug_regions) {
         int i = 0;
         for (i = 0; i < debug_regions->len; i++) {
             Range *range = &g_array_index(debug_regions, Range, i);
             if (range_contains(range, addr)) {
                 return true;
             }
         }
         return false;
     } else {
         return true;
     }
 }


 void qemu_set_dfilter_ranges(const char *filter_spec, Error **errp)
 {
     gchar **ranges = g_strsplit(filter_spec, ",", 0);
     int i;

     if (debug_regions) {
         g_array_unref(debug_regions);
         debug_regions = NULL;
     }

     debug_regions = g_array_sized_new(FALSE, FALSE,
                                       sizeof(Range), g_strv_length(ranges));
     for (i = 0; ranges[i]; i++) {
         const char *r = ranges[i];
         const char *range_op, *r2, *e;
         uint64_t r1val, r2val, lob, upb;
         struct Range range;

         range_op = strstr(r, "-");
         r2 = range_op ? range_op + 1 : NULL;
         if (!range_op) {
             range_op = strstr(r, "+");
             r2 = range_op ? range_op + 1 : NULL;
         }
         if (!range_op) {
             range_op = strstr(r, "..");
             r2 = range_op ? range_op + 2 : NULL;
         }
         if (!range_op) {
             error_setg(errp, "Bad range specifier");
             goto out;
         }

         if (qemu_strtou64(r, &e, 0, &r1val)
             || e != range_op) {
             error_setg(errp, "Invalid number to the left of %.*s",
                        (int)(r2 - range_op), range_op);
             goto out;
         }
         if (qemu_strtou64(r2, NULL, 0, &r2val)) {
             error_setg(errp, "Invalid number to the right of %.*s",
                        (int)(r2 - range_op), range_op);
             goto out;
         }

         switch (*range_op) {
         case '+':
             lob = r1val;
             upb = r1val + r2val - 1;
             break;
         case '-':
             upb = r1val;
             lob = r1val - (r2val - 1);
             break;
         case '.':
             lob = r1val;
             upb = r2val;
             break;
         default:
             g_assert_not_reached();
         }
         if (lob > upb) {
             error_setg(errp, "Invalid range");
             goto out;
         }
         range_set_bounds(&range, lob, upb);
         g_array_append_val(debug_regions, range);
     }
 out:
     g_strfreev(ranges);
 }

 /* fflush() the log file */
 void qemu_log_flush(void)
 {
     QemuLogFile *logfile;

     rcu_read_lock();
     logfile = atomic_rcu_read(&qemu_logfile);
     if (logfile) {
         fflush(logfile->fd);
     }
     rcu_read_unlock();
 }

 /* Close the log file */
 void qemu_log_close(void)
 {
     QemuLogFile *logfile;

     qemu_mutex_lock(&qemu_logfile_mutex);
     logfile = qemu_logfile;

     if (logfile) {
         atomic_rcu_set(&qemu_logfile, NULL);
         call_rcu(logfile, qemu_logfile_free, rcu);
     }
     qemu_mutex_unlock(&qemu_logfile_mutex);
 }

 const QEMULogItem qemu_log_items[] = {
     { CPU_LOG_TB_OUT_ASM, "out_asm",
       "show generated host assembly code for each compiled TB" },
     { CPU_LOG_TB_IN_ASM, "in_asm",
       "show target assembly code for each compiled TB" },
     { CPU_LOG_TB_OP, "op",
       "show micro ops for each compiled TB" },
     { CPU_LOG_TB_OP_OPT, "op_opt",
       "show micro ops after optimization" },
     { CPU_LOG_TB_OP_IND, "op_ind",
       "show micro ops before indirect lowering" },
     { CPU_LOG_INT, "int",
       "show interrupts/exceptions in short format" },
     { CPU_LOG_EXEC, "exec",
       "show trace before each executed TB (lots of logs)" },
     { CPU_LOG_TB_CPU, "cpu",
       "show CPU registers before entering a TB (lots of logs)" },
     { CPU_LOG_TB_FPU, "fpu",
       "include FPU registers in the 'cpu' logging" },
     { CPU_LOG_MMU, "mmu",
       "log MMU-related activities" },
     { CPU_LOG_PCALL, "pcall",
       "x86 only: show protected mode far calls/returns/exceptions" },
     { CPU_LOG_RESET, "cpu_reset",
       "show CPU state before CPU resets" },
     { LOG_UNIMP, "unimp",
       "log unimplemented functionality" },
     { LOG_GUEST_ERROR, "guest_errors",
       "log when the guest OS does something invalid (eg accessing a\n"
       "non-existent register)" },
     { CPU_LOG_PAGE, "page",
       "dump pages at beginning of user mode emulation" },
     { CPU_LOG_TB_NOCHAIN, "nochain",
       "do not chain compiled TBs so that \"exec\" and \"cpu\" show\n"
       "complete traces" },
 #ifdef CONFIG_PLUGIN
     { CPU_LOG_PLUGIN, "plugin", "output from TCG plugins\n"},
 #endif
     { LOG_STRACE, "strace",
       "log every user-mode syscall, its input, and its result" },
     { 0, NULL, NULL },
 };

 /* takes a comma separated list of log masks. Return 0 if error. */
 int qemu_str_to_log_mask(const char *str)
 {
     const QEMULogItem *item;
     int mask = 0;
     char **parts = g_strsplit(str, ",", 0);
     char **tmp;

     for (tmp = parts; tmp && *tmp; tmp++) {
         if (g_str_equal(*tmp, "all")) {
             for (item = qemu_log_items; item->mask != 0; item++) {
                 mask |= item->mask;
             }
 #ifdef CONFIG_TRACE_LOG
         } else if (g_str_has_prefix(*tmp, "trace:") && (*tmp)[6] != '\0') {
             trace_enable_events((*tmp) + 6);
             mask |= LOG_TRACE;
 #endif
         } else {
             for (item = qemu_log_items; item->mask != 0; item++) {
                 if (g_str_equal(*tmp, item->name)) {
                     goto found;
                 }
             }
             goto error;
         found:
             mask |= item->mask;
         }
     }

     g_strfreev(parts);
     return mask;

  error:
     g_strfreev(parts);
     return 0;
 }

 void qemu_print_log_usage(FILE *f)
 {
     const QEMULogItem *item;
     fprintf(f, "Log items (comma separated):\n");
     for (item = qemu_log_items; item->mask != 0; item++) {
         fprintf(f, "%-15s %s\n", item->name, item->help);
     }
 #ifdef CONFIG_TRACE_LOG
     fprintf(f, "trace:PATTERN   enable trace events\n");
     fprintf(f, "\nUse \"-d trace:help\" to get a list of trace events.\n\n");
 #endif
 }
	/*
	* Logging support
	*
	* Copyright (c) 2003 Fabrice Bellard
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, see <http://www.gnu.org/licenses/>.
	*/

	#include "qemu/osdep.h"
	#include "qemu/log.h"
	#include "qemu/range.h"
	#include "qemu/error-report.h"
	#include "qapi/error.h"
	#include "qemu/cutils.h"
	#include "trace/control.h"
	#include "qemu/thread.h"

	static char *logfilename;
	static QemuMutex qemu_logfile_mutex;
	QemuLogFile *qemu_logfile;
	int qemu_loglevel;
	static int log_append = 0;
	static GArray *debug_regions;

	/* Return the number of characters emitted. */
	int qemu_log(const char *fmt, ...)
	{
	int ret = 0;
	QemuLogFile *logfile;

	rcu_read_lock();
	logfile = atomic_rcu_read(&qemu_logfile);
	if (logfile) {
	va_list ap;
	va_start(ap, fmt);
	ret = vfprintf(logfile->fd, fmt, ap);
	va_end(ap);

	/* Don't pass back error results. */
	if (ret < 0) {
	ret = 0;
	}
	}
	rcu_read_unlock();
	return ret;
	}

	static void __attribute__((__constructor__)) qemu_logfile_init(void)
	{
	qemu_mutex_init(&qemu_logfile_mutex);
	}

	static void qemu_logfile_free(QemuLogFile *logfile)
	{
	g_assert(logfile);

	if (logfile->fd != stderr) {
	fclose(logfile->fd);
	}
	g_free(logfile);
	}

	static bool log_uses_own_buffers;

	/* enable or disable low levels log */
	void qemu_set_log(int log_flags)
	{
	bool need_to_open_file = false;
	QemuLogFile *logfile;

	qemu_loglevel = log_flags;
	#ifdef CONFIG_TRACE_LOG
	qemu_loglevel \|= LOG_TRACE;
	#endif
	/*
	* In all cases we only log if qemu_loglevel is set.
	* Also:
	* If not daemonized we will always log either to stderr
	* or to a file (if there is a logfilename).
	* If we are daemonized,
	* we will only log if there is a logfilename.
	*/
	if (qemu_loglevel && (!is_daemonized() \|\| logfilename)) {
	need_to_open_file = true;
	}
	qemu_mutex_lock(&qemu_logfile_mutex);
	if (qemu_logfile && !need_to_open_file) {
	logfile = qemu_logfile;
	atomic_rcu_set(&qemu_logfile, NULL);
	call_rcu(logfile, qemu_logfile_free, rcu);
	} else if (!qemu_logfile && need_to_open_file) {
	logfile = g_new0(QemuLogFile, 1);
	if (logfilename) {
	logfile->fd = fopen(logfilename, log_append ? "a" : "w");
	if (!logfile->fd) {
	g_free(logfile);
	perror(logfilename);
	_exit(1);
	}
	/* In case we are a daemon redirect stderr to logfile */
	if (is_daemonized()) {
	dup2(fileno(logfile->fd), STDERR_FILENO);
	fclose(logfile->fd);
	/* This will skip closing logfile in qemu_log_close() */
	logfile->fd = stderr;
	}
	} else {
	/* Default to stderr if no log file specified */
	assert(!is_daemonized());
	logfile->fd = stderr;
	}
	/* must avoid mmap() usage of glibc by setting a buffer "by hand" */
	if (log_uses_own_buffers) {
	static char logfile_buf[4096];

	setvbuf(logfile->fd, logfile_buf, _IOLBF, sizeof(logfile_buf));
	} else {
	#if defined(_WIN32)
	/* Win32 doesn't support line-buffering, so use unbuffered output. */
	setvbuf(logfile->fd, NULL, _IONBF, 0);
	#else
	setvbuf(logfile->fd, NULL, _IOLBF, 0);
	#endif
	log_append = 1;
	}
	atomic_rcu_set(&qemu_logfile, logfile);
	}
	qemu_mutex_unlock(&qemu_logfile_mutex);
	}

	void qemu_log_needs_buffers(void)
	{
	log_uses_own_buffers = true;
	}

	/*
	* Allow the user to include %d in their logfile which will be
	* substituted with the current PID. This is useful for debugging many
	* nested linux-user tasks but will result in lots of logs.
	*
	* filename may be NULL. In that case, log output is sent to stderr
	*/
	void qemu_set_log_filename(const char filename, Error *errp)
	{
	g_free(logfilename);
	logfilename = NULL;

	if (filename) {
	char *pidstr = strstr(filename, "%");
	if (pidstr) {
	/* We only accept one %d, no other format strings */
	if (pidstr[1] != 'd' \|\| strchr(pidstr + 2, '%')) {
	error_setg(errp, "Bad logfile format: %s", filename);
	return;
	} else {
	logfilename = g_strdup_printf(filename, getpid());
	}
	} else {
	logfilename = g_strdup(filename);
	}
	}

	qemu_log_close();
	qemu_set_log(qemu_loglevel);
	}

	/* Returns true if addr is in our debug filter or no filter defined
	*/
	bool qemu_log_in_addr_range(uint64_t addr)
	{
	if (debug_regions) {
	int i = 0;
	for (i = 0; i < debug_regions->len; i++) {
	Range *range = &g_array_index(debug_regions, Range, i);
	if (range_contains(range, addr)) {
	return true;
	}
	}
	return false;
	} else {
	return true;
	}
	}


	void qemu_set_dfilter_ranges(const char filter_spec, Error *errp)
	{
	gchar **ranges = g_strsplit(filter_spec, ",", 0);
	int i;

	if (debug_regions) {
	g_array_unref(debug_regions);
	debug_regions = NULL;
	}

	debug_regions = g_array_sized_new(FALSE, FALSE,
	sizeof(Range), g_strv_length(ranges));
	for (i = 0; ranges[i]; i++) {
	const char *r = ranges[i];
	const char range_op, r2, *e;
	uint64_t r1val, r2val, lob, upb;
	struct Range range;

	range_op = strstr(r, "-");
	r2 = range_op ? range_op + 1 : NULL;
	if (!range_op) {
	range_op = strstr(r, "+");
	r2 = range_op ? range_op + 1 : NULL;
	}
	if (!range_op) {
	range_op = strstr(r, "..");
	r2 = range_op ? range_op + 2 : NULL;
	}
	if (!range_op) {
	error_setg(errp, "Bad range specifier");
	goto out;
	}

	if (qemu_strtou64(r, &e, 0, &r1val)
	\|\| e != range_op) {
	error_setg(errp, "Invalid number to the left of %.*s",
	(int)(r2 - range_op), range_op);
	goto out;
	}
	if (qemu_strtou64(r2, NULL, 0, &r2val)) {
	error_setg(errp, "Invalid number to the right of %.*s",
	(int)(r2 - range_op), range_op);
	goto out;
	}

	switch (*range_op) {
	case '+':
	lob = r1val;
	upb = r1val + r2val - 1;
	break;
	case '-':
	upb = r1val;
	lob = r1val - (r2val - 1);
	break;
	case '.':
	lob = r1val;
	upb = r2val;
	break;
	default:
	g_assert_not_reached();
	}
	if (lob > upb) {
	error_setg(errp, "Invalid range");
	goto out;
	}
	range_set_bounds(&range, lob, upb);
	g_array_append_val(debug_regions, range);
	}
	out:
	g_strfreev(ranges);
	}

	/* fflush() the log file */
	void qemu_log_flush(void)
	{
	QemuLogFile *logfile;

	rcu_read_lock();
	logfile = atomic_rcu_read(&qemu_logfile);
	if (logfile) {
	fflush(logfile->fd);
	}
	rcu_read_unlock();
	}

	/* Close the log file */
	void qemu_log_close(void)
	{
	QemuLogFile *logfile;

	qemu_mutex_lock(&qemu_logfile_mutex);
	logfile = qemu_logfile;

	if (logfile) {
	atomic_rcu_set(&qemu_logfile, NULL);
	call_rcu(logfile, qemu_logfile_free, rcu);
	}
	qemu_mutex_unlock(&qemu_logfile_mutex);
	}

	const QEMULogItem qemu_log_items[] = {
	{ CPU_LOG_TB_OUT_ASM, "out_asm",
	"show generated host assembly code for each compiled TB" },
	{ CPU_LOG_TB_IN_ASM, "in_asm",
	"show target assembly code for each compiled TB" },
	{ CPU_LOG_TB_OP, "op",
	"show micro ops for each compiled TB" },
	{ CPU_LOG_TB_OP_OPT, "op_opt",
	"show micro ops after optimization" },
	{ CPU_LOG_TB_OP_IND, "op_ind",
	"show micro ops before indirect lowering" },
	{ CPU_LOG_INT, "int",
	"show interrupts/exceptions in short format" },
	{ CPU_LOG_EXEC, "exec",
	"show trace before each executed TB (lots of logs)" },
	{ CPU_LOG_TB_CPU, "cpu",
	"show CPU registers before entering a TB (lots of logs)" },
	{ CPU_LOG_TB_FPU, "fpu",
	"include FPU registers in the 'cpu' logging" },
	{ CPU_LOG_MMU, "mmu",
	"log MMU-related activities" },
	{ CPU_LOG_PCALL, "pcall",
	"x86 only: show protected mode far calls/returns/exceptions" },
	{ CPU_LOG_RESET, "cpu_reset",
	"show CPU state before CPU resets" },
	{ LOG_UNIMP, "unimp",
	"log unimplemented functionality" },
	{ LOG_GUEST_ERROR, "guest_errors",
	"log when the guest OS does something invalid (eg accessing a\n"
	"non-existent register)" },
	{ CPU_LOG_PAGE, "page",
	"dump pages at beginning of user mode emulation" },
	{ CPU_LOG_TB_NOCHAIN, "nochain",
	"do not chain compiled TBs so that \"exec\" and \"cpu\" show\n"
	"complete traces" },
	#ifdef CONFIG_PLUGIN
	{ CPU_LOG_PLUGIN, "plugin", "output from TCG plugins\n"},
	#endif
	{ LOG_STRACE, "strace",
	"log every user-mode syscall, its input, and its result" },
	{ 0, NULL, NULL },
	};

	/* takes a comma separated list of log masks. Return 0 if error. */
	int qemu_str_to_log_mask(const char *str)
	{
	const QEMULogItem *item;
	int mask = 0;
	char **parts = g_strsplit(str, ",", 0);
	char **tmp;

	for (tmp = parts; tmp && *tmp; tmp++) {
	if (g_str_equal(*tmp, "all")) {
	for (item = qemu_log_items; item->mask != 0; item++) {
	mask \|= item->mask;
	}
	#ifdef CONFIG_TRACE_LOG
	} else if (g_str_has_prefix(tmp, "trace:") && (tmp)[6] != '\0') {
	trace_enable_events((*tmp) + 6);
	mask \|= LOG_TRACE;
	#endif
	} else {
	for (item = qemu_log_items; item->mask != 0; item++) {
	if (g_str_equal(*tmp, item->name)) {
	goto found;
	}
	}
	goto error;
	found:
	mask \|= item->mask;
	}
	}

	g_strfreev(parts);
	return mask;

	error:
	g_strfreev(parts);
	return 0;
	}

	void qemu_print_log_usage(FILE *f)
	{
	const QEMULogItem *item;
	fprintf(f, "Log items (comma separated):\n");
	for (item = qemu_log_items; item->mask != 0; item++) {
	fprintf(f, "%-15s %s\n", item->name, item->help);
	}
	#ifdef CONFIG_TRACE_LOG
	fprintf(f, "trace:PATTERN enable trace events\n");
	fprintf(f, "\nUse \"-d trace:help\" to get a list of trace events.\n\n");
	#endif
	}