core: error out in nm_utils_kill_child_{sync,async}() if first waitpid() gives ECHILD

It is wrong trying to send the signal still. Just error out.

Note that ECHILD indicates that the process is either not a child
or was already reaped. In both cases, that is a bug of the caller
who must keep accurate track of the child's process ID.

2 files changed, 17 insertions, 25 deletions

diff --git a/src/core/nm-core-utils.c b/src/core/nm-core-utils.c
index 880483b817..7482292034 100644
--- a/src/core/nm-core-utils.c
+++ b/src/core/nm-core-utils.c
@@ -507,16 +507,13 @@ nm_utils_kill_child_async(pid_t                   pid,
         return;
     } else if (ret != 0) {
         errsv = errno;
-        /* ECHILD means, the process is not a child/does not exist or it has SIGCHILD blocked. */
-        if (errsv != ECHILD) {
-            nm_log_err(LOGD_CORE | log_domain,
-                       LOG_NAME_FMT ": unexpected error while waitpid: %s (%d)",
-                       LOG_NAME_ARGS,
-                       nm_strerror_native(errsv),
-                       errsv);
-            _kc_invoke_callback(pid, log_domain, log_name, callback, user_data, FALSE, -1);
-            return;
-        }
+        nm_log_err(LOGD_CORE | log_domain,
+                   LOG_NAME_FMT ": unexpected error while waitpid: %s (%d)",
+                   LOG_NAME_ARGS,
+                   nm_strerror_native(errsv),
+                   errsv);
+        _kc_invoke_callback(pid, log_domain, log_name, callback, user_data, FALSE, -1);
+        return;
     }
 
     /* send the first signal. */
@@ -647,15 +644,12 @@ nm_utils_kill_child_sync(pid_t       pid,
         goto out;
     } else if (ret != 0) {
         errsv = errno;
-        /* ECHILD means, the process is not a child/does not exist or it has SIGCHILD blocked. */
-        if (errsv != ECHILD) {
-            nm_log_err(LOGD_CORE | log_domain,
-                       LOG_NAME_FMT ": unexpected error while waitpid: %s (%d)",
-                       LOG_NAME_ARGS,
-                       nm_strerror_native(errsv),
-                       errsv);
-            goto out;
-        }
+        nm_log_err(LOGD_CORE | log_domain,
+                   LOG_NAME_FMT ": unexpected error while waitpid: %s (%d)",
+                   LOG_NAME_ARGS,
+                   nm_strerror_native(errsv),
+                   errsv);
+        goto out;
     }
 
     /* send first signal @sig */
diff --git a/src/core/tests/test-core-with-expect.c b/src/core/tests/test-core-with-expect.c
index b05144ac21..015101262c 100644
--- a/src/core/tests/test-core-with-expect.c
+++ b/src/core/tests/test-core-with-expect.c
@@ -333,9 +333,8 @@ do_test_nm_utils_kill_child(void)
 
     /* pid3s should not be a valid process, hence the call should fail. Note, that there
      * is a race here. */
-    NMTST_EXPECT_NM_ERROR(
-        "kill child process 'test-s-3-2' (*): failed due to unexpected return value -1 by waitpid "
-        "(No child process*, 10) after sending no signal (0)");
+    NMTST_EXPECT_NM_ERROR("kill child process 'test-s-3-2' (*): unexpected error while waitpid: No "
+                          "child process* (10)");
     test_nm_utils_kill_child_sync_do("test-s-3-2", pid3s, 0, 0, FALSE, NULL);
 
     NMTST_EXPECT_NM_DEBUG("kill child process 'test-s-4' (*): waiting up to 50 milliseconds for "
@@ -396,9 +395,8 @@ do_test_nm_utils_kill_child(void)
 
     /* pid3a should not be a valid process, hence the call should fail. Note, that there
      * is a race here. */
-    NMTST_EXPECT_NM_ERROR(
-        "kill child process 'test-a-3-2' (*): failed due to unexpected return value -1 by waitpid "
-        "(No child process*, 10) after sending no signal (0)");
+    NMTST_EXPECT_NM_ERROR("kill child process 'test-a-3-2' (*): unexpected error while "
+                          "waitpid: No child process* (10)");
     NMTST_EXPECT_NM_DEBUG(
         "kill child process 'test-a-3-2' (*): invoke callback: killing child failed");
     test_nm_utils_kill_child_async_do("test-a-3-2", pid3a, 0, 0, FALSE, NULL);