Move the definition of the log() macro to xenstored_core.h in order
to make it usable from other source files, too.

While at it preserve errno from being modified.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
---
 tools/xenstore/xenstored_core.c | 14 --------------
 tools/xenstore/xenstored_core.h | 15 +++++++++++++++
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 60433265ed..48c2793aeb 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -88,20 +88,6 @@ TDB_CONTEXT *tdb_ctx = NULL;
 
 static const char *sockmsg_string(enum xsd_sockmsg_type type);
 
-#define log(...)							\
-	do {								\
-		char *s = talloc_asprintf(NULL, __VA_ARGS__);		\
-		if (s) {						\
-			trace("%s\n", s);				\
-			syslog(LOG_ERR, "%s\n",  s);			\
-			talloc_free(s);					\
-		} else {						\
-			trace("talloc failure during logging\n");	\
-			syslog(LOG_ERR, "talloc failure during logging\n"); \
-		}							\
-	} while (0)
-
-
 int quota_nb_entry_per_domain = 1000;
 int quota_nb_watch_per_domain = 128;
 int quota_max_entry_size = 2048; /* 2K */
diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h
index 3c4e27d0dd..3b96ecd018 100644
--- a/tools/xenstore/xenstored_core.h
+++ b/tools/xenstore/xenstored_core.h
@@ -267,6 +267,21 @@ void trace(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
 void reopen_log(void);
 void close_log(void);
 
+#define log(...)							\
+	do {								\
+		int _saved_errno = errno;				\
+		char *s = talloc_asprintf(NULL, __VA_ARGS__);		\
+		if (s) {						\
+			trace("%s\n", s);				\
+			syslog(LOG_ERR, "%s\n",	s);			\
+			talloc_free(s);					\
+		} else {						\
+			trace("talloc failure during logging\n");	\
+			syslog(LOG_ERR, "talloc failure during logging\n"); \
+		}							\
+		errno = _saved_errno;					\
+	} while (0)
+
 extern int orig_argc;
 extern char **orig_argv;
 
-- 
2.35.3