log: fix repeated invocation of vsnprintf()/vaprintf() in log_struct()

[elogind.git] / src / shared / log.c

diff --git a/src/shared/log.c b/src/shared/log.c
index 96634645bc7c1ebe0e5c6d03686cc888ab7236cd..63578683ab6575b73df32ddd9164893471d5f186 100644 (file)
--- a/src/shared/log.c
+++ b/src/shared/log.c
@@ -27,6 +27,7 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <stddef.h>
+#include <printf.h>
 
 #include "log.h"
 #include "util.h"
@@ -73,14 +74,9 @@ static int log_open_console(void) {
                 return 0;
 
         if (getpid() == 1) {
-
                 console_fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
-                if (console_fd < 0) {
-                        log_error("Failed to open /dev/console for logging: %s", strerror(-console_fd));
+                if (console_fd < 0)
                         return console_fd;
-                }
-
-                log_debug("Successfully opened /dev/console for logging.");
         } else
                 console_fd = STDERR_FILENO;
 
@@ -102,12 +98,8 @@ static int log_open_kmsg(void) {
                 return 0;
 
         kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC);
-        if (kmsg_fd < 0) {
-                log_error("Failed to open /dev/kmsg for logging: %s", strerror(errno));
+        if (kmsg_fd < 0)
                 return -errno;
-        }
-
-        log_debug("Successfully opened /dev/kmsg for logging.");
 
         return 0;
 }
@@ -174,13 +166,10 @@ static int log_open_syslog(void) {
         } else
                 syslog_is_stream = false;
 
-        log_debug("Successfully opened syslog for logging.");
-
         return 0;
 
 fail:
         log_close_syslog();
-        log_debug("Failed to open syslog for logging: %s", strerror(-r));
         return r;
 }
 
@@ -215,13 +204,10 @@ static int log_open_journal(void) {
                 goto fail;
         }
 
-        log_debug("Successfully opened journal for logging.");
-
         return 0;
 
 fail:
         log_close_journal();
-        log_debug("Failed to open journal for logging: %s", strerror(-r));
         return r;
 }
 
@@ -720,11 +706,23 @@ int log_struct_internal(
                 va_start(ap, format);
                 while (format && n + 1 < ELEMENTSOF(iovec)) {
                         char *buf;
+                        va_list aq;
+
+                        /* We need to copy the va_list structure,
+                         * since vasprintf() leaves it afterwards at
+                         * an undefined location */
 
-                        if (vasprintf(&buf, format, ap) < 0) {
+                        va_copy(aq, ap);
+                        if (vasprintf(&buf, format, aq) < 0) {
+                                va_end(aq);
                                 r = -ENOMEM;
                                 goto finish;
                         }
+                        va_end(aq);
+
+                        /* Now, jump enough ahead, so that we point to
+                         * the next format string */
+                        VA_FORMAT_ADVANCE(format, ap);
 
                         IOVEC_SET_STRING(iovec[n++], buf);
 
@@ -734,7 +732,6 @@ int log_struct_internal(
 
                         format = va_arg(ap, char *);
                 }
-                va_end(ap);
 
                 zero(mh);
                 mh.msg_iov = iovec;
@@ -746,6 +743,7 @@ int log_struct_internal(
                         r = 1;
 
         finish:
+                va_end(ap);
                 for (i = 1; i < n; i += 2)
                         free(iovec[i].iov_base);
 
@@ -757,8 +755,11 @@ int log_struct_internal(
 
                 va_start(ap, format);
                 while (format) {
+                        va_list aq;
 
-                        vsnprintf(buf, sizeof(buf), format, ap);
+                        va_copy(aq, ap);
+                        vsnprintf(buf, sizeof(buf), format, aq);
+                        va_end(aq);
                         char_array_0(buf);
 
                         if (startswith(buf, "MESSAGE=")) {
@@ -766,6 +767,8 @@ int log_struct_internal(
                                 break;
                         }
 
+                        VA_FORMAT_ADVANCE(format, ap);
+
                         format = va_arg(ap, char *);
                 }
                 va_end(ap);