Merge pull request #10853 from poettering/thaw-containers

main: don't freeze PID 1 in containers, exit with non-zero instead

src/core/main.c

@@ -130,7 +130,14 @@ static uint64_t arg_default_tasks_max = UINT64_MAX;
 static sd_id128_t arg_machine_id = {};
 static EmergencyAction arg_cad_burst_action = EMERGENCY_ACTION_REBOOT_FORCE;
 
-_noreturn_ static void freeze_or_reboot(void) {
+_noreturn_ static void freeze_or_exit_or_reboot(void) {
+
+        /* If we are running in a contianer, let's prefer exiting, after all we can propagate an exit code to the
+         * container manager, and thus inform it that something went wrong. */
+        if (detect_container() > 0) {
+                log_emergency("Exiting PID 1...");
+                exit(EXIT_EXCEPTION);
+        }
 
         if (arg_crash_reboot) {
                 log_notice("Rebooting in 10s...");
@@ -185,7 +192,7 @@ _noreturn_ static void crash(int sig) {
                         (void) kill(pid, sig); /* raise() would kill the parent */
 
                         assert_not_reached("We shouldn't be here...");
-                        _exit(EXIT_FAILURE);
+                        _exit(EXIT_EXCEPTION);
                 } else {
                         siginfo_t status;
                         int r;
@@ -231,14 +238,14 @@ _noreturn_ static void crash(int sig) {
                         (void) execle("/bin/sh", "/bin/sh", NULL, environ);
 
                         log_emergency_errno(errno, "execle() failed: %m");
-                        _exit(EXIT_FAILURE);
+                        _exit(EXIT_EXCEPTION);
                 } else {
                         log_info("Spawned crash shell as PID "PID_FMT".", pid);
                         (void) wait_for_terminate(pid, NULL);
                 }
         }
 
-        freeze_or_reboot();
+        freeze_or_exit_or_reboot();
 }
 
 static void install_crash_handler(void) {
@@ -2622,8 +2629,8 @@ finish:
                 if (error_message)
                         manager_status_printf(NULL, STATUS_TYPE_EMERGENCY,
                                               ANSI_HIGHLIGHT_RED "!!!!!!" ANSI_NORMAL,
-                                              "%s, freezing.", error_message);
+                                              "%s.", error_message);
-                freeze_or_reboot();
+                freeze_or_exit_or_reboot();
         }
 
         return retval;

src/nspawn/nspawn-stub-pid1.c

@@ -5,6 +5,8 @@
 #include <sys/prctl.h>
 #include <unistd.h>
 
+#include "def.h"
+#include "exit-status.h"
 #include "fd-util.h"
 #include "log.h"
 #include "missing.h"
@@ -12,7 +14,6 @@
 #include "process-util.h"
 #include "signal-util.h"
 #include "time-util.h"
-#include "def.h"
 
 static int reset_environ(const char *new_environment, size_t length) {
         unsigned long start, end;
@@ -122,7 +123,7 @@ int stub_pid1(sd_id128_t uuid) {
                         if (si.si_pid == pid && si.si_code == CLD_EXITED)
                                 r = si.si_status; /* pass on exit code */
                         else
-                                r = 255; /* signal, coredump, timeout, … */
+                                r = EXIT_EXCEPTION; /* signal, coredump, timeout, … */
 
                         goto finish;
                 }

src/shared/exit-status.c

@@ -19,9 +19,10 @@ const char* exit_status_to_string(int status, ExitStatusLevel level) {
          *  79…199 │ (Currently unmapped)
          * 200…241 │ systemd's private error codes (might be extended to 254 in future development)
          * 242…254 │ (Currently unmapped, but see above)
-         *   255   │ (We should probably stay away from that one, it's frequently used by applications to indicate an
+         *
-         *         │ exit reason that cannot really be expressed in a single exit status value — such as a propagated
+         *   255   │ EXIT_EXCEPTION (We use this to propagate exit-by-signal events. It's frequently used by others apps (like bash)
-         *         │ signal or such)
+         *         │ to indicate exit reason that cannot really be expressed in a single exit status value — such as a propagated
+         *         │ signal or such, and we follow that logic here.)
          */
 
         switch (status) {  /* We always cover the ISO C ones */
@@ -155,6 +156,9 @@ const char* exit_status_to_string(int status, ExitStatusLevel level) {
 
                 case EXIT_CONFIGURATION_DIRECTORY:
                         return "CONFIGURATION_DIRECTORY";
+
+                case EXIT_EXCEPTION:
+                        return "EXCEPTION";
                 }
         }
 

src/shared/exit-status.h

@@ -69,6 +69,8 @@ enum {
         EXIT_CACHE_DIRECTORY,
         EXIT_LOGS_DIRECTORY, /* 240 */
         EXIT_CONFIGURATION_DIRECTORY,
+
+        EXIT_EXCEPTION = 255,  /* Whenever we want to propagate an abnormal/signal exit, in line with bash */
 };
 
 typedef enum ExitStatusLevel {