img: Extend task image with state and exit code

Introduce 3 states we will have to work with:

* alive for tasks sleeping or running
* dead for zombies
* stopped for stopped tasks. We cannot distinguish tasks in this state now,
  but with freezer cgroup this will become possible
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

cr-dump.c

@@ -626,6 +626,9 @@ static int dump_task_core_seized(pid_t pid, int pid_dir, struct proc_pid_stat *s
 	core->tc.mm_brk = brk;
 	pr_info("OK\n");
 
+	core->tc.task_state = TASK_ALIVE;
+	core->tc.exit_code = 0;
+
 	return dump_task_core(core, cr_fdset);
 
 err_free:
@@ -1016,6 +1019,9 @@ static int dump_task_thread(pid_t pid, struct cr_fdset *cr_fdset)
 		goto err_free;
 	}
 
+	core->tc.task_state = TASK_ALIVE;
+	core->tc.exit_code = 0;
+
 	return dump_task_core(core, cr_fdset);
 
 err_free:

cr-show.c

@@ -319,6 +319,18 @@ err:
 	return;
 }
 
+static inline char *task_state_str(int state)
+{
+	switch (state) {
+	case TASK_ALIVE:
+		return "running/sleeping";
+	case TASK_DEAD:
+		return "zombie";
+	default:
+		return "UNKNOWN";
+	}
+}
+
 static void show_core_rest(int fd_core)
 {
 	struct task_core_entry tc;
@@ -331,6 +343,10 @@ static void show_core_rest(int fd_core)
 	pr_info("\n\t---[Task parameters]---\n");
 	pr_info("\tPersonality:  %x\n", tc.personality);
 	pr_info("\tCommand:      %s\n", tc.comm);
+	pr_info("\tState:        %d (%s)\n", (int)tc.task_state,
+			task_state_str((int)tc.task_state));
+	if (tc.task_state == TASK_DEAD)
+		pr_info("\t   Exit code: %u\n", (unsigned int)tc.exit_code);
 	pr_info("\tBrk:          %lx\n", tc.mm_brk);
 	pr_info("\tStart code:   %lx\n", tc.mm_start_code);
 	pr_info("\tEnd code:     %lx\n", tc.mm_end_code);

include/image.h

@@ -223,6 +223,9 @@ struct ckpt_arch_entry {
 #define CKPT_CORE_SIZE			(2 * 4096)
 
 struct task_core_entry {
+	u8				task_state;
+	u8				pad[3];
+	u32				exit_code;
 
 	u32				personality;
 	u8				comm[TASK_COMM_LEN];
@@ -248,6 +251,10 @@ struct core_entry {
 	};
 } __packed;
 
+#define TASK_ALIVE	0x1
+#define TASK_DEAD	0x2
+#define TASK_STOPPED	0x3 /* FIXME - implement */
+
 #endif /* CONFIG_X86_64 */
 
 /*