[CRIU] [PATCH v2 03/15] sysctl: add req->has to mark successful sysctl_op request

[Pavel Tikhomirov]

must be carefull allocating memory for sysctl_req as trash values
can cause segmentation fault

Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
---
 criu/include/sysctl.h | 1 +
 criu/sysctl.c         | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/criu/include/sysctl.h b/criu/include/sysctl.h
index b949a40..9ee93c6 100644
--- a/criu/include/sysctl.h
+++ b/criu/include/sysctl.h
@@ -6,6 +6,7 @@ struct sysctl_req {
 	void	*arg;
 	int	type;
 	int	flags;
+	int	*has;
 };
 
 extern int sysctl_op(struct sysctl_req *req, size_t nr_req, int op, unsigned int ns);
diff --git a/criu/sysctl.c b/criu/sysctl.c
index 21ae4ce..bd584bd 100644
--- a/criu/sysctl.c
+++ b/criu/sysctl.c
@@ -261,6 +261,10 @@ static int __userns_sysctl_op(void *arg, int proc_fd, pid_t pid)
 			goto out;
 		}
 
+		if (req->has)
+			/* sysctl in question exists */
+			*req->has = 1;
+
 		/* save a pointer to the req, so we don't need to recompute its
 		 * location
 		 */
@@ -371,6 +375,10 @@ static int __nonuserns_sysctl_op(struct sysctl_req *req, size_t nr_req, int op)
 			goto out;
 		}
 
+		if (req->has)
+			/* sysctl in question exists */
+			 *req->has = 1;
+
 		ret = do_sysctl_op(fd, req, op);
 		if (ret)
 			goto out;
-- 
1.9.3