Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20201106' into staging

[qemu.git] / util / log.c

diff --git a/util/log.c b/util/log.c
index 867264da8d05c55f670f3243673796171ac4a029..4b423062aa8f0e2becaa05f1e88e57f1bd74bc87 100644 (file)
--- a/util/log.c
+++ b/util/log.c
@@ -25,6 +25,7 @@
 #include "qemu/cutils.h"
 #include "trace/control.h"
 #include "qemu/thread.h"
+#include "qemu/lockable.h"
 
 static char *logfilename;
 static QemuMutex qemu_logfile_mutex;
@@ -40,7 +41,7 @@ int qemu_log(const char *fmt, ...)
     QemuLogFile *logfile;
 
     rcu_read_lock();
-    logfile = atomic_rcu_read(&qemu_logfile);
+    logfile = qatomic_rcu_read(&qemu_logfile);
     if (logfile) {
         va_list ap;
         va_start(ap, fmt);
@@ -94,10 +95,10 @@ void qemu_set_log(int log_flags)
     if (qemu_loglevel && (!is_daemonized() || logfilename)) {
         need_to_open_file = true;
     }
-    qemu_mutex_lock(&qemu_logfile_mutex);
+    QEMU_LOCK_GUARD(&qemu_logfile_mutex);
     if (qemu_logfile && !need_to_open_file) {
         logfile = qemu_logfile;
-        atomic_rcu_set(&qemu_logfile, NULL);
+        qatomic_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);
@@ -134,9 +135,8 @@ void qemu_set_log(int log_flags)
 #endif
             log_append = 1;
         }
-        atomic_rcu_set(&qemu_logfile, logfile);
+        qatomic_rcu_set(&qemu_logfile, logfile);
     }
-    qemu_mutex_unlock(&qemu_logfile_mutex);
 }
 
 void qemu_log_needs_buffers(void)
@@ -148,25 +148,29 @@ void qemu_log_needs_buffers(void)
  * 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)
 {
-    char *pidstr;
     g_free(logfilename);
     logfilename = NULL;
 
-    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);
+    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);
 }
@@ -268,7 +272,7 @@ void qemu_log_flush(void)
     QemuLogFile *logfile;
 
     rcu_read_lock();
-    logfile = atomic_rcu_read(&qemu_logfile);
+    logfile = qatomic_rcu_read(&qemu_logfile);
     if (logfile) {
         fflush(logfile->fd);
     }
@@ -284,7 +288,7 @@ void qemu_log_close(void)
     logfile = qemu_logfile;
 
     if (logfile) {
-        atomic_rcu_set(&qemu_logfile, NULL);
+        qatomic_rcu_set(&qemu_logfile, NULL);
         call_rcu(logfile, qemu_logfile_free, rcu);
     }
     qemu_mutex_unlock(&qemu_logfile_mutex);
@@ -328,6 +332,8 @@ const QEMULogItem qemu_log_items[] = {
 #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 },
 };