3 files changed, 15 insertions, 19 deletions

diff --git a/src/lib/err/torerr.c b/src/lib/err/torerr.c
index 92ef80e56a..c2dd862e11 100644
--- a/src/lib/err/torerr.c
+++ b/src/lib/err/torerr.c
@@ -151,29 +151,27 @@ tor_log_reset_sigsafe_err_fds(void)
 }
 
 /**
- * Close the list of fds that get errors from inside a signal handler or
+ * Flush the list of fds that get errors from inside a signal handler or
  * other emergency condition. These fds are shared with the logging code:
- * closing them flushes the log buffers, and prevents any further logging.
+ * flushing them also flushes the log buffers.
  *
- * This function closes stderr, so it should only be called immediately before
- * process shutdown.
+ * This function is safe to call during signal handlers.
  */
 void
-tor_log_close_sigsafe_err_fds(void)
+tor_log_flush_sigsafe_err_fds(void)
 {
+  /* If we don't have fsync() in unistd.h, we can't flush the logs. */
+#ifdef HAVE_FSYNC
   int n_fds, i;
   const int *fds = NULL;
 
   n_fds = tor_log_get_sigsafe_err_fds(&fds);
   for (i = 0; i < n_fds; ++i) {
-    /* tor_log_close_sigsafe_err_fds_on_error() is called on error and on
-     * shutdown, so we can't log or take any useful action if close()
-     * fails. */
-    (void)close(fds[i]);
+    /* This function is called on error and on shutdown, so we don't log, or
+     * take any other action, if fsync() fails. */
+    (void)fsync(fds[i]);
   }
-
-  /* Don't even try logging, we've closed all the log fds. */
-  tor_log_set_sigsafe_err_fds(NULL, 0);
+#endif
 }
 
 /**
@@ -217,13 +215,13 @@ tor_raw_assertion_failed_msg_(const char *file, int line, const char *expr,
 
 /**
  * Call the abort() function to kill the current process with a fatal
- * error. But first, close the raw error file descriptors, so error messages
+ * error. But first, flush the raw error file descriptors, so error messages
  * are written before process termination.
  **/
 void
 tor_raw_abort_(void)
 {
-  tor_log_close_sigsafe_err_fds();
+  tor_log_flush_sigsafe_err_fds();
   abort();
 }
 
diff --git a/src/lib/err/torerr.h b/src/lib/err/torerr.h
index f5b36eef9c..ce1b049c47 100644
--- a/src/lib/err/torerr.h
+++ b/src/lib/err/torerr.h
@@ -40,7 +40,7 @@ void tor_log_err_sigsafe(const char *m, ...);
 int tor_log_get_sigsafe_err_fds(const int **out);
 void tor_log_set_sigsafe_err_fds(const int *fds, int n);
 void tor_log_reset_sigsafe_err_fds(void);
-void tor_log_close_sigsafe_err_fds(void);
+void tor_log_flush_sigsafe_err_fds(void);
 void tor_log_sigsafe_err_set_granularity(int ms);
 
 void tor_raw_abort_(void) ATTR_NORETURN;
diff --git a/src/lib/err/torerr_sys.c b/src/lib/err/torerr_sys.c
index aa49ba36bd..46fc853550 100644
--- a/src/lib/err/torerr_sys.c
+++ b/src/lib/err/torerr_sys.c
@@ -27,11 +27,9 @@ subsys_torerr_initialize(void)
 static void
 subsys_torerr_shutdown(void)
 {
-  /* Stop handling signals with backtraces, then close the logs. */
+  /* Stop handling signals with backtraces, then flush the logs. */
   clean_up_backtrace_handler();
-  /* We can't log any log messages after this point: we've closed all the log
-   * fds, including stdio. */
-  tor_log_close_sigsafe_err_fds();
+  tor_log_flush_sigsafe_err_fds();
 }
 
 const subsys_fns_t sys_torerr = {