[CRIU] [PATCH] criu: dump and restore a thread name

[Andrei Vagin]

From: Andrei Vagin <avagin at virtuozzo.com>

Reported-by: 志平 林 <larry.lin at outlook.com>
Signed-off-by: Andrei Vagin <avagin at virtuozzo.com>
---
 criu/cr-dump.c          |  3 +++
 criu/cr-restore.c       |  5 +++++
 criu/include/parasite.h |  1 +
 criu/include/restorer.h |  1 +
 criu/pie/parasite.c     | 18 +++++++++++++++---
 criu/pie/restorer.c     |  6 ++++++
 images/core.proto       |  1 +
 7 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/criu/cr-dump.c b/criu/cr-dump.c
index aec726dad..fd7743d80 100644
--- a/criu/cr-dump.c
+++ b/criu/cr-dump.c
@@ -732,6 +732,9 @@ int dump_thread_core(int pid, CoreEntry *core, const struct parasite_dump_thread
 			tc->has_pdeath_sig = true;
 			tc->pdeath_sig = ti->pdeath_sig;
 		}
+		tc->comm = xstrdup(ti->comm);
+		if (tc->comm == NULL)
+			return -1;
 	}
 
 	return ret;
diff --git a/criu/cr-restore.c b/criu/cr-restore.c
index c6c9a7daf..86c793ee9 100644
--- a/criu/cr-restore.c
+++ b/criu/cr-restore.c
@@ -3723,6 +3723,11 @@ static int sigreturn_restore(pid_t pid, struct task_restore_args *task_args, uns
 		if (construct_sigframe(sigframe, sigframe, blkset, tcore))
 			goto err;
 
+		if (thread_args[i].comm)
+			strncpy(thread_args[i].comm, tcore->thread_core->comm, TASK_COMM_LEN);
+		else
+			strncpy(thread_args[i].comm, core->tc->comm, TASK_COMM_LEN);
+
 		if (thread_args[i].pid[0] != pid)
 			core_entry__free_unpacked(tcore, NULL);
 
diff --git a/criu/include/parasite.h b/criu/include/parasite.h
index 9de0d2e9a..9e2e1498e 100644
--- a/criu/include/parasite.h
+++ b/criu/include/parasite.h
@@ -170,6 +170,7 @@ struct parasite_dump_thread {
 	tls_t				tls;
 	stack_t				sas;
 	int				pdeath_sig;
+	char				comm[TASK_COMM_LEN];
 	struct parasite_dump_creds	creds[0];
 };
 
diff --git a/criu/include/restorer.h b/criu/include/restorer.h
index 15307d9c0..60089667a 100644
--- a/criu/include/restorer.h
+++ b/criu/include/restorer.h
@@ -100,6 +100,7 @@ struct thread_restore_args {
 
 	bool				check_only;
 	struct thread_creds_args	*creds_args;
+	char				comm[TASK_COMM_LEN];
 } __aligned(64);
 
 typedef long (*thread_restore_fcall_t) (struct thread_restore_args *args);
diff --git a/criu/pie/parasite.c b/criu/pie/parasite.c
index 7a48f324e..c7d5fd7eb 100644
--- a/criu/pie/parasite.c
+++ b/criu/pie/parasite.c
@@ -172,16 +172,28 @@ static int dump_thread_common(struct parasite_dump_thread *ti)
 
 	arch_get_tls(&ti->tls);
 	ret = sys_prctl(PR_GET_TID_ADDRESS, (unsigned long) &ti->tid_addr, 0, 0, 0);
-	if (ret)
+	if (ret) {
+		pr_err("Unable to get the clear_child_tid address: %d\n", ret);
 		goto out;
+	}
 
 	ret = sys_sigaltstack(NULL, &ti->sas);
-	if (ret)
+	if (ret) {
+		pr_err("Unable to get signal stack context: %d\n", ret);
 		goto out;
+	}
 
 	ret = sys_prctl(PR_GET_PDEATHSIG, (unsigned long)&ti->pdeath_sig, 0, 0, 0);
-	if (ret)
+	if (ret) {
+		pr_err("Unable to get the parent death signal: %d\n", ret);
+		goto out;
+	}
+
+	ret = sys_prctl(PR_GET_NAME, (unsigned long) &ti->comm, 0, 0, 0);
+	if (ret) {
+		pr_err("Unable to get the thread name: %d\n", ret);
 		goto out;
+	}
 
 	ret = dump_creds(ti->creds);
 out:
diff --git a/criu/pie/restorer.c b/criu/pie/restorer.c
index 091026103..73e868f97 100644
--- a/criu/pie/restorer.c
+++ b/criu/pie/restorer.c
@@ -549,6 +549,12 @@ long __export_restore_thread(struct thread_restore_args *args)
 	if (ret)
 		goto core_restore_end;
 
+	ret = sys_prctl(PR_SET_NAME, (unsigned long) &args->comm, 0, 0, 0);
+	if (ret) {
+		pr_err("Unable to set a thread name: %d\n", ret);
+		goto core_restore_end;
+	}
+
 	pr_info("%ld: Restored\n", sys_gettid());
 
 	restore_finish_stage(task_entries_local, CR_STATE_RESTORE);
diff --git a/images/core.proto b/images/core.proto
index 0291fae68..7eb17b466 100644
--- a/images/core.proto
+++ b/images/core.proto
@@ -87,6 +87,7 @@ message thread_core_entry {
 
 	optional signal_queue_entry	signals_p	= 9;
 	optional creds_entry		creds		= 10;
+	optional string			comm		= 11;
 }
 
 message task_rlimits_entry {
-- 
2.13.6