memfd_secret: save secretmem stat

Adds support to save secretmem page stats when C/R a memfd_secret
fd containing process.

Updates images/stats.proto to add statistics about C/R
memfd_secret fd.

Signed-off-by: Dhanuka Warusadura <[email protected]>

Author: warusadura

criu/include/stats.h

@@ -33,6 +33,10 @@ enum {
 	CNT_SHPAGES_SKIPPED_PARENT,
 	CNT_SHPAGES_WRITTEN,
 
+	CNT_SECMEMPAGES_SCANNED,
+	CNT_SECMEMPAGES_SKIPPED_PARENT,
+	CNT_SECMEMPAGES_WRITTEN,
+
 	DUMP_CNT_NR_STATS,
 };
 

criu/stats.c

@@ -186,6 +186,13 @@ void write_stats(int what)
 		ds_entry.shpages_written = dstats->counts[CNT_SHPAGES_WRITTEN];
 		ds_entry.has_shpages_written = true;
 
+		ds_entry.secmempages_scanned = dstats->counts[CNT_SECMEMPAGES_SCANNED];
+		ds_entry.has_secmempages_scanned = true;
+		ds_entry.secmempages_skipped_parent = dstats->counts[CNT_SECMEMPAGES_SKIPPED_PARENT];
+		ds_entry.has_secmempages_skipped_parent = true;
+		ds_entry.secmempages_written = dstats->counts[CNT_SECMEMPAGES_WRITTEN];
+		ds_entry.has_secmempages_written = true;
+
 		name = "dump";
 	} else if (what == RESTORE_STATS) {
 		stats.restore = &rs_entry;

images/stats.proto

@@ -22,6 +22,10 @@ message dump_stats_entry {
 	optional uint64			shpages_scanned		= 12;
 	optional uint64			shpages_skipped_parent	= 13;
 	optional uint64			shpages_written		= 14;
+
+        optional uint64                 secmempages_scanned     = 15;
+        optional uint64                 secmempages_skipped_parent = 16;
+        optional uint64                 secmempages_written     = 17;
 }
 
 message restore_stats_entry {