zdtm: Add MAP_HUGETLB memory mapping test

This commit add a test for checkpoint/restore MAP_HUGETLB memory mappings.
A new zdtm helper get_mapping_dev() is added to get the device number of
the memory mapping.

Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>

test/zdtm.py

@@ -2566,6 +2566,17 @@ def clean_stuff(opts):
             f.clean()
 
 
+def set_nr_hugepages(nr):
+    orig_hugepages = 0
+    with open("/proc/sys/vm/nr_hugepages", "r") as f:
+        orig_hugepages = int(f.read())
+
+    with open("/proc/sys/vm/nr_hugepages", "w") as f:
+        f.write("{}\n".format(nr))
+
+    return orig_hugepages
+
+
 #
 # main() starts here
 #
@@ -2738,7 +2749,11 @@ if opts['action'] == 'run':
 for tst in test_classes.values():
     tst.available()
 
+orig_hugepages = set_nr_hugepages(20)
+
 opts['action'](opts)
 
+set_nr_hugepages(orig_hugepages)
+
 for tst in test_classes.values():
     tst.cleanup()

test/zdtm/lib/Makefile

@@ -4,7 +4,7 @@ CFLAGS	+= $(USERCFLAGS)
 
 LIB	:= libzdtmtst.a
 
-LIBSRC	:= datagen.c msg.c parseargs.c test.c streamutil.c lock.c ns.c tcp.c unix.c fs.c sysctl.c
+LIBSRC	:= datagen.c msg.c parseargs.c test.c streamutil.c lock.c ns.c tcp.c unix.c fs.c sysctl.c mem.c
 
 PKG_CONFIG ?= pkg-config
 pkg-config-check = $(shell sh -c '$(PKG_CONFIG) $(1) && echo y')

test/zdtm/lib/mem.c

@@ -0,0 +1,32 @@
+#include <sys/sysmacros.h>
+#include <string.h>
+#include <stdint.h>
+
+#include "zdtmtst.h"
+
+dev_t get_mapping_dev(void *addr)
+{
+	char buf[1024];
+	FILE *f;
+	unsigned int major, minor;
+	int ret;
+
+	f = fopen("/proc/self/maps", "r");
+	if (f == NULL) {
+		pr_perror("Failed to open maps file");
+		return (dev_t)-1;
+	}
+
+	while (fgets(buf, sizeof(buf), f)) {
+		if ((unsigned long)addr == strtoul(buf, NULL, 16)) {
+			ret = sscanf(buf, "%*x-%*x %*c%*c%*c%*c %*x %x:%x", &major, &minor);
+			if (ret != 2) {
+				pr_err("Can't parse /proc/self/maps\n");
+				return (dev_t)-1;
+			}
+			return makedev(major, minor);
+		}
+	}
+
+	return (dev_t)-1;
+}

test/zdtm/lib/zdtmtst.h

@@ -164,6 +164,7 @@ extern const char *test_doc;
 extern int tcp_init_server_with_opts(int family, int *port, struct zdtm_tcp_opts *opts);
 extern pid_t sys_clone_unified(unsigned long flags, void *child_stack, void *parent_tid, void *child_tid,
 			       unsigned long newtls);
+extern dev_t get_mapping_dev(void *addr);
 
 #define ssprintf(s, fmt, ...)                                        \
 	({                                                           \

test/zdtm/static/Makefile

@@ -131,6 +131,7 @@ TST_NOFILE	:=				\
 		maps02				\
 		maps04				\
 		maps05				\
+		maps09				\
 		mlock_setuid			\
 		xids00				\
 		groups				\

test/zdtm/static/maps09.c

@@ -0,0 +1,89 @@
+#include <sys/mman.h>
+
+#include "zdtmtst.h"
+
+#define MEM_SIZE   (4UL * (1UL << 20)) /* 4MB */
+#define MEM_OFFSET (MEM_SIZE - PAGE_SIZE)
+
+const char *test_doc = "Test MAP_HUGETLB mapping";
+const char *test_author = "Bui Quang Minh <minhquangbui99@gmail.com>";
+
+int main(int argc, char **argv)
+{
+	void *m1, *m2;
+	dev_t dev1, dev2;
+	uint32_t crc;
+
+	test_init(argc, argv);
+	m1 = mmap(NULL, MEM_SIZE, PROT_READ | PROT_WRITE, MAP_HUGETLB | MAP_SHARED | MAP_ANONYMOUS, 0, 0);
+	if (m1 == MAP_FAILED) {
+		pr_perror("Failed to mmap %lu Mb anonymous shared memory", MEM_SIZE >> 20);
+		return 1;
+	}
+
+	dev1 = get_mapping_dev(m1);
+	if (dev1 == (dev_t)-1) {
+		fail("Can't get mapping dev");
+		return 1;
+	}
+
+	m2 = mmap(NULL, MEM_SIZE, PROT_READ | PROT_WRITE, MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
+	if (m2 == MAP_FAILED) {
+		pr_perror("Failed to mmap %lu Mb anonymous private memory", MEM_SIZE >> 20);
+		return 1;
+	}
+
+	dev2 = get_mapping_dev(m2);
+	if (dev2 == (dev_t)-1) {
+		fail("Can't get mapping dev");
+		return 1;
+	}
+
+	crc = ~0;
+	datagen(m1, PAGE_SIZE, &crc);
+	crc = ~0;
+	datagen(m1 + MEM_OFFSET, PAGE_SIZE, &crc);
+	crc = ~0;
+	datagen(m2, PAGE_SIZE, &crc);
+	crc = ~0;
+	datagen(m2 + MEM_OFFSET, PAGE_SIZE, &crc);
+	crc = ~0;
+
+	test_daemon();
+	test_waitsig();
+
+	crc = ~0;
+	if (datachk(m1, PAGE_SIZE, &crc)) {
+		fail("Data mismatch");
+		return 1;
+	}
+	crc = ~0;
+	if (datachk(m1 + MEM_OFFSET, PAGE_SIZE, &crc)) {
+		fail("Data mismatch");
+		return 1;
+	}
+	crc = ~0;
+	if (datachk(m2, PAGE_SIZE, &crc)) {
+		fail("Data mismatch");
+		return 1;
+	}
+	crc = ~0;
+	if (datachk(m2 + MEM_OFFSET, PAGE_SIZE, &crc)) {
+		fail("Data mismatch");
+		return 1;
+	}
+
+	if (dev1 != get_mapping_dev(m1)) {
+		fail("Mapping dev mismatch");
+		return 1;
+	}
+
+	if (dev2 != get_mapping_dev(m2)) {
+		fail("Mapping dev mismatch");
+		return 1;
+	}
+
+	pass();
+
+	return 0;
+}