/*
* 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 2.1 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"
#include "qemu/lockable.h"
#include "qemu/rcu.h"
#ifdef CONFIG_LINUX
#include <sys/syscall.h>
#endif
typedef struct RCUCloseFILE {
struct rcu_head rcu;
FILE *fd;
} RCUCloseFILE;
/* Mutex covering the other global_* variables. */
static QemuMutex global_mutex;
static char *global_filename;
static FILE *global_file;
static __thread FILE *thread_file;
static __thread Notifier qemu_log_thread_cleanup_notifier;
int qemu_loglevel;
static bool log_append;
static bool log_per_thread;
static GArray *debug_regions;
/* Returns true if qemu_log() will really write somewhere. */
bool qemu_log_enabled(void)
{
return log_per_thread || qatomic_read(&global_file) != NULL;
}
/* Returns true if qemu_log() will write somewhere other than stderr. */
bool qemu_log_separate(void)
{
if (log_per_thread) {
return true;
} else {
FILE *logfile = qatomic_read(&global_file);
return logfile && logfile != stderr;
}
}
static int log_thread_id(void)
{
#ifdef CONFIG_GETTID
return gettid();
#elif defined(SYS_gettid)
return syscall(SYS_gettid);
#else
static int counter;
return qatomic_fetch_inc(&counter);
#endif
}
static void qemu_log_thread_cleanup(Notifier *n, void *unused)
{
fclose(thread_file);
thread_file = NULL;
}
/* Lock/unlock output. */
FILE *qemu_log_trylock(void)
{
FILE *logfile;
logfile = thread_file;
if (!logfile) {
if (log_per_thread) {
g_autofree char *filename
= g_strdup_printf(global_filename, log_thread_id());
logfile = fopen(filename, "w");
if (!logfile) {
return NULL;
}
thread_file = logfile;
qemu_log_thread_cleanup_notifier.notify = qemu_log_thread_cleanup;
qemu_thread_atexit_add(&qemu_log_thread_cleanup_notifier);
} else {
rcu_read_lock();
/*
* FIXME: typeof_strip_qual, as used by qatomic_rcu_read,
* does not work with pointers to undefined structures,
* such as we have with struct _IO_FILE and musl libc.
* Since all we want is a read of a pointer, cast to void**,
* which does work with typeof_strip_qual.
*/
logfile = qatomic_rcu_read((void **)&global_file);
if (!logfile) {
rcu_read_unlock();
return NULL;
}
}
}
qemu_flockfile(logfile);
return logfile;
}
void qemu_log_unlock(FILE *logfile)
{
if (logfile) {
fflush(logfile);
qemu_funlockfile(logfile);
if (!log_per_thread) {
rcu_read_unlock();
}
}
}
void qemu_log(const char *fmt, ...)
{
FILE *f = qemu_log_trylock();
if (f) {
va_list ap;
va_start(ap, fmt);
vfprintf(f, fmt, ap);
va_end(ap);
qemu_log_unlock(f);
}
}
static void __attribute__((__constructor__)) startup(void)
{
qemu_mutex_init(&global_mutex);
}
static void rcu_close_file(RCUCloseFILE *r)
{
fclose(r->fd);
g_free(r);
}
/**
* valid_filename_template:
*
* Validate the filename template. Require %d if per_thread, allow it
* otherwise; require no other % within the template.
*/
typedef enum {
vft_error,
vft_stderr,
vft_strdup,
vft_pid_printf,
} ValidFilenameTemplateResult;
static ValidFilenameTemplateResult
valid_filename_template(const char *filename, bool per_thread, Error **errp)
{
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 template: %s", filename);
return 0;
}
return per_thread ? vft_strdup : vft_pid_printf;
}
}
if (per_thread) {
error_setg(errp, "Filename template with '%%d' required for 'tid'");
return vft_error;
}
return filename ? vft_strdup : vft_stderr;
}
/* enable or disable low levels log */
static bool qemu_set_log_internal(const char *filename, bool changed_name,
int log_flags, Error **errp)
{
bool need_to_open_file;
bool daemonized;
bool per_thread;
FILE *logfile;
QEMU_LOCK_GUARD(&global_mutex);
logfile = global_file;
/* The per-thread flag is immutable. */
if (log_per_thread) {
log_flags |= LOG_PER_THREAD;
} else {
if (global_filename) {
log_flags &= ~LOG_PER_THREAD;
}
}
per_thread = log_flags & LOG_PER_THREAD;
if (changed_name) {
char *newname = NULL;
/*
* Once threads start opening their own log files, we have no
* easy mechanism to tell them all to close and re-open.
* There seems little cause to do so either -- this option
* will most often be used at user-only startup.
*/
if (log_per_thread) {
error_setg(errp, "Cannot change log filename after setting 'tid'");
return false;
}
switch (valid_filename_template(filename, per_thread, errp)) {
case vft_error:
return false;
case vft_stderr:
break;
case vft_strdup:
newname = g_strdup(filename);
break;
case vft_pid_printf:
newname = g_strdup_printf(filename, getpid());
break;
}
g_free(global_filename);
global_filename = newname;
filename = newname;
} else {
filename = global_filename;
if (per_thread &&
valid_filename_template(filename, true, errp) == vft_error) {
return false;
}
}
/* Once the per-thread flag is set, it cannot be unset. */
if (per_thread) {
log_per_thread = true;
}
/* The flag itself is not relevant for need_to_open_file. */
log_flags &= ~LOG_PER_THREAD;
#ifdef CONFIG_TRACE_LOG
log_flags |= LOG_TRACE;
#endif
qemu_loglevel = log_flags;
/*
* In all cases we only log if qemu_loglevel is set.
* Also:
* If per-thread, open the file for each thread in qemu_log_lock.
* If not daemonized we will always log either to stderr
* or to a file (if there is a filename).
* If we are daemonized, we will only log if there is a filename.
*/
daemonized = is_daemonized();
need_to_open_file = log_flags && !per_thread && (!daemonized || filename);
if (logfile && (!need_to_open_file || changed_name)) {
qatomic_rcu_set(&global_file, NULL);
if (logfile != stderr) {
RCUCloseFILE *r = g_new0(RCUCloseFILE, 1);
r->fd = logfile;
call_rcu(r, rcu_close_file, rcu);
}
logfile = NULL;
}
if (!logfile && need_to_open_file) {
if (filename) {
logfile = fopen(filename, log_append ? "a" : "w");
if (!logfile) {
error_setg_errno(errp, errno, "Error opening logfile %s",
filename);
return false;
}
/* In case we are a daemon redirect stderr to logfile */
if (daemonized) {
dup2(fileno(logfile), STDERR_FILENO);
fclose(logfile);
/* This will skip closing logfile in rcu_close_file. */
logfile = stderr;
}
} else {
/* Default to stderr if no log file specified */
assert(!daemonized);
logfile = stderr;
}
log_append = 1;
qatomic_rcu_set(&global_file, logfile);
}
return true;
}
bool qemu_set_log(int log_flags, Error **errp)
{
return qemu_set_log_internal(NULL, false, log_flags, errp);
}
bool qemu_set_log_filename(const char *filename, Error **errp)
{
return qemu_set_log_internal(filename, true, qemu_loglevel, errp);
}
bool qemu_set_log_filename_flags(const char *name, int flags, Error **errp)
{
return qemu_set_log_internal(name, true, flags, errp);
}
/* 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);
}
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" },
{ LOG_PER_THREAD, "tid",
"open a separate log file per thread; filename must contain '%d'" },
{ 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
}
