qemu/util/log.c
Paolo Bonzini c586eac336 log: do not log if QEMU is daemonized but without -D
Commit 96c33a4 ("log: Redirect stderr to logfile if deamonized",
2016-02-22) wanted to move stderr of a daemonized QEMU to the file
specified with -D.

However, if -D was not passed, the patch had the side effect of not
redirecting stderr to /dev/null.  This happened because qemu_logfile
was set to stderr rather than the expected value of NULL.  The fix
is simply in the "if" condition of do_qemu_set_log; the "if" for
closing the file is also changed to match.

Reported-by: Jan Tomko <jtomko@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-07 13:18:28 +01:00

204 lines
5.9 KiB
C

/*
* 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-common.h"
#include "qemu/log.h"
#include "trace/control.h"
static char *logfilename;
FILE *qemu_logfile;
int qemu_loglevel;
static int log_append = 0;
void qemu_log(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
if (qemu_logfile) {
vfprintf(qemu_logfile, fmt, ap);
}
va_end(ap);
}
void qemu_log_mask(int mask, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
if ((qemu_loglevel & mask) && qemu_logfile) {
vfprintf(qemu_logfile, fmt, ap);
}
va_end(ap);
}
/* enable or disable low levels log */
void do_qemu_set_log(int log_flags, bool use_own_buffers)
{
qemu_loglevel = log_flags;
#ifdef CONFIG_TRACE_LOG
qemu_loglevel |= LOG_TRACE;
#endif
if (!qemu_logfile &&
(is_daemonized() ? logfilename != NULL : qemu_loglevel)) {
if (logfilename) {
qemu_logfile = fopen(logfilename, log_append ? "a" : "w");
if (!qemu_logfile) {
perror(logfilename);
_exit(1);
}
/* In case we are a daemon redirect stderr to logfile */
if (is_daemonized()) {
dup2(fileno(qemu_logfile), STDERR_FILENO);
fclose(qemu_logfile);
/* This will skip closing logfile in qemu_log_close() */
qemu_logfile = stderr;
}
} else {
/* Default to stderr if no log file specified */
assert(!is_daemonized());
qemu_logfile = stderr;
}
/* must avoid mmap() usage of glibc by setting a buffer "by hand" */
if (use_own_buffers) {
static char logfile_buf[4096];
setvbuf(qemu_logfile, logfile_buf, _IOLBF, sizeof(logfile_buf));
} else {
#if defined(_WIN32)
/* Win32 doesn't support line-buffering, so use unbuffered output. */
setvbuf(qemu_logfile, NULL, _IONBF, 0);
#else
setvbuf(qemu_logfile, NULL, _IOLBF, 0);
#endif
log_append = 1;
}
}
if (qemu_logfile &&
(is_daemonized() ? logfilename == NULL : !qemu_loglevel)) {
qemu_log_close();
}
}
void qemu_set_log_filename(const char *filename)
{
g_free(logfilename);
logfilename = g_strdup(filename);
qemu_log_close();
qemu_set_log(qemu_loglevel);
}
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 (x86 only: before eflags optimization) and\n"
"after liveness analysis" },
{ 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 state before block translation" },
{ 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" },
{ 0, NULL, NULL },
};
static int cmp1(const char *s1, int n, const char *s2)
{
if (strlen(s2) != n) {
return 0;
}
return memcmp(s1, s2, n) == 0;
}
/* 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;
const char *p, *p1;
p = str;
mask = 0;
for (;;) {
p1 = strchr(p, ',');
if (!p1) {
p1 = p + strlen(p);
}
if (cmp1(p,p1-p,"all")) {
for (item = qemu_log_items; item->mask != 0; item++) {
mask |= item->mask;
}
#ifdef CONFIG_TRACE_LOG
} else if (strncmp(p, "trace:", 6) == 0 && p + 6 != p1) {
trace_enable_events(p + 6);
mask |= LOG_TRACE;
#endif
} else {
for (item = qemu_log_items; item->mask != 0; item++) {
if (cmp1(p, p1 - p, item->name)) {
goto found;
}
}
return 0;
found:
mask |= item->mask;
}
if (*p1 != ',') {
break;
}
p = p1 + 1;
}
return mask;
}
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
}