[CRIU] [PATCH RFC] criu: add a debug version of rst-malloc

[Andrei Vagin]

From: Andrei Vagin <avagin at virtuozzo.com>

rst_mem_alloc() can move all allocated objects and
the problem is that we don't know when it will do.

With this patch, if the criu is built with DEBUG=1,
rst_mem_alloc() will move objects each time.

Signed-off-by: Andrei Vagin <avagin at virtuozzo.com>
---
 .travis.yml                 |  1 +
 criu/rst-malloc.c           | 19 +++++++++++++++++++
 scripts/travis/travis-tests |  2 +-
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index a5dfb9f..d62e086 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,6 +7,7 @@ services:
 env:
   - TR_ARCH=local       GCOV=1
   - TR_ARCH=local       CLANG=1
+  - TR_ARCH=local       CRIU_DEBUG=1
   - TR_ARCH=alpine
   - TR_ARCH=x86_64
   - TR_ARCH=armv7hf
diff --git a/criu/rst-malloc.c b/criu/rst-malloc.c
index 4f7357c..057fa31 100644
--- a/criu/rst-malloc.c
+++ b/criu/rst-malloc.c
@@ -23,6 +23,11 @@ static inline unsigned long rst_mem_grow(unsigned long need_size)
 {
 	int rst_mem_batch = 2 * page_size();
 
+#ifdef CR_DEBUG
+	if (need_size == 0)
+		return 0;
+#endif
+
 	need_size = round_up(need_size, page_size());
 	if (likely(need_size < rst_mem_batch))
 		need_size = rst_mem_batch;
@@ -88,8 +93,18 @@ static int grow_remap(struct rst_mem_type_s *t, int flag, unsigned long size)
 		 * a completely new one and force callers use objects'
 		 * cpos-s.
 		 */
+#ifdef CR_DEBUG
+		/* Move vma each time to another palce */
+		void *ptr = mmap(NULL, t->size + size, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+		if (ptr == MAP_FAILED)
+			return -1;
+		aux = mremap(t->buf, t->size,
+				t->size + size, MREMAP_MAYMOVE | MREMAP_FIXED, ptr);
+		munmap(t->buf, t->size);
+#else
 		aux = mremap(t->buf, t->size,
 				t->size + size, MREMAP_MAYMOVE);
+#endif
 	}
 	if (aux == MAP_FAILED)
 		return -1;
@@ -175,6 +190,10 @@ void *rst_mem_alloc(unsigned long size, int type)
 		pr_perror("Can't grow rst mem");
 		return NULL;
 	}
+#ifdef CR_DEBUG
+	else if (type == RM_PRIVATE && t->grow(t, 0)) /* Move a vma to another place */
+		return NULL;
+#endif
 
 	ret = t->free_mem;
 	t->free_mem += size;
diff --git a/scripts/travis/travis-tests b/scripts/travis/travis-tests
index 37117a3..3897542 100755
--- a/scripts/travis/travis-tests
+++ b/scripts/travis/travis-tests
@@ -41,7 +41,7 @@ ulimit -c unlimited
 echo "|`pwd`/test/abrt.sh %P %p %s %e" > /proc/sys/kernel/core_pattern
 
 export GCOV
-time make CC="$CC" -j4
+time make CC="$CC" DEBUG="$CRIU_DEBUG" -j4
 time make CC="$CC" -j4 -C test/zdtm
 
 [ -f "$CCACHE_LOGFILE" ] && cat $CCACHE_LOGFILE
-- 
2.7.4