This adds a test to validate mirror functionality with mremap()
system call on shared anon mappings.
Suggested-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Signed-off-by: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/vm/Makefile | 1 +
.../selftests/vm/mremap_mirror_shared_anon.c | 54 ++++++++++++++++++++++
2 files changed, 55 insertions(+)
create mode 100644 tools/testing/selftests/vm/mremap_mirror_shared_anon.c
diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
index cbb29e4..11657ff5 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -17,6 +17,7 @@ TEST_GEN_FILES += transhuge-stress
TEST_GEN_FILES += userfaultfd
TEST_GEN_FILES += mlock-random-test
TEST_GEN_FILES += virtual_address_range
+TEST_GEN_FILES += mremap_mirror_shared_anon
TEST_PROGS := run_vmtests
diff --git a/tools/testing/selftests/vm/mremap_mirror_shared_anon.c b/tools/testing/selftests/vm/mremap_mirror_shared_anon.c
new file mode 100644
index 0000000..b0adbb2
--- /dev/null
+++ b/tools/testing/selftests/vm/mremap_mirror_shared_anon.c
@@ -0,0 +1,54 @@
+/*
+ * Test to verify mirror functionality with mremap() system
+ * call for shared anon mappings.
+ *
+ * Copyright (C) 2017 Anshuman Khandual, IBM Corporation
+ *
+ * Licensed under GPL V2
+ */
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+
+#define PATTERN 0xbe
+#define ALLOC_SIZE 0x10000UL /* Works for 64K and 4K pages */
+
+int test_mirror(char *old, char *new, unsigned long size)
+{
+ unsigned long i;
+
+ for (i = 0; i < size; i++) {
+ if (new[i] != old[i]) {
+ printf("Mismatch at new[%lu] expected "
+ "%d received %d\n", i, old[i], new[i]);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ char *ptr, *mirror_ptr;
+
+ ptr = mmap(NULL, ALLOC_SIZE, PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+ if (ptr == MAP_FAILED) {
+ perror("map() failed");
+ return -1;
+ }
+ memset(ptr, PATTERN, ALLOC_SIZE);
+
+ mirror_ptr = (char *) mremap(ptr, 0, ALLOC_SIZE, 1);
+ if (mirror_ptr == MAP_FAILED) {
+ perror("mremap() failed");
+ return -1;
+ }
+
+ if (test_mirror(ptr, mirror_ptr, ALLOC_SIZE))
+ return 1;
+ return 0;
+}
--
1.8.5.2
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