From: Simon Guo <wei.guo.simon@xxxxxxxxx>
This patch will randomly perform mlock/mlock2 on a given
memory region, and verify the RLIMIT_MEMLOCK limitation
works properly.
Suggested-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Simon Guo <wei.guo.simon@xxxxxxxxx>
---
tools/testing/selftests/vm/Makefile | 4 +-
tools/testing/selftests/vm/mlock-intersect-test.c | 76 ------
tools/testing/selftests/vm/mlock-random-test.c | 293 ++++++++++++++++++++++
3 files changed, 295 insertions(+), 78 deletions(-)
delete mode 100644 tools/testing/selftests/vm/mlock-intersect-test.c
create mode 100644 tools/testing/selftests/vm/mlock-random-test.c
diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
index a0412a8..bbab7f4 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -10,7 +10,7 @@ BINARIES += on-fault-limit
BINARIES += thuge-gen
BINARIES += transhuge-stress
BINARIES += userfaultfd
-BINARIES += mlock-intersect-test
+BINARIES += mlock-random-test
all: $(BINARIES)
%: %.c
@@ -18,7 +18,7 @@ all: $(BINARIES)
userfaultfd: userfaultfd.c ../../../../usr/include/linux/kernel.h
$(CC) $(CFLAGS) -O2 -o $@ $< -lpthread
-mlock-intersect-test: mlock-intersect-test.c
+mlock-random-test: mlock-random-test.c
$(CC) $(CFLAGS) -o $@ $< -lcap
../../../../usr/include/linux/kernel.h:
diff --git a/tools/testing/selftests/vm/mlock-intersect-test.c b/tools/testing/selftests/vm/mlock-intersect-test.c
deleted file mode 100644
index f78e68a..0000000
--- a/tools/testing/selftests/vm/mlock-intersect-test.c
+++ /dev/null
@@ -1,76 +0,0 @@
-/*
- * It tests the duplicate mlock result:
- * - the ulimit of lock page is 64k
- * - allocate address area 64k starting from p
- * - mlock [p -- p + 30k]
- * - Then mlock address [ p -- p + 40k ]
- *
- * It should succeed since totally we locked
- * 40k < 64k limitation.
- *
- * It should not be run with CAP_IPC_LOCK.
- */
-#include <stdlib.h>
-#include <stdio.h>
-#include <unistd.h>
-#include <sys/resource.h>
-#include <sys/capability.h>
-#include <sys/mman.h>
-#include "mlock2.h"
-
-int main(int argc, char **argv)
-{
- struct rlimit new;
- char *p = NULL;
- cap_t cap = cap_init();
- int i;
-
- /* drop capabilities including CAP_IPC_LOCK */
- if (cap_set_proc(cap))
- return -1;
-
- /* set mlock limits to 64k */
- new.rlim_cur = 65536;
- new.rlim_max = 65536;
- setrlimit(RLIMIT_MEMLOCK, &new);
-
- /* test VM_LOCK */
- p = malloc(1024 * 64);
- if (mlock(p, 1024 * 30)) {
- printf("mlock() 30k return failure.\n");
- return -1;
- }
- for (i = 0; i < 10; i++) {
- if (mlock(p, 1024 * 40)) {
- printf("mlock() #%d 40k returns failure.\n", i);
- return -1;
- }
- }
- for (i = 0; i < 10; i++) {
- if (mlock2_(p, 1024 * 40, MLOCK_ONFAULT)) {
- printf("mlock2_() #%d 40k returns failure.\n", i);
- return -1;
- }
- }
- free(p);
-
- /* Test VM_LOCKONFAULT */
- p = malloc(1024 * 64);
- if (mlock2_(p, 1024 * 30, MLOCK_ONFAULT)) {
- printf("mlock2_() 30k return failure.\n");
- return -1;
- }
- for (i = 0; i < 10; i++) {
- if (mlock2_(p, 1024 * 40, MLOCK_ONFAULT)) {
- printf("mlock2_() #%d 40k returns failure.\n", i);
- return -1;
- }
- }
- for (i = 0; i < 10; i++) {
- if (mlock(p, 1024 * 40)) {
- printf("mlock() #%d 40k returns failure.\n", i);
- return -1;
- }
- }
- return 0;
-}
diff --git a/tools/testing/selftests/vm/mlock-random-test.c b/tools/testing/selftests/vm/mlock-random-test.c
new file mode 100644
index 0000000..83de4f5
--- /dev/null
+++ b/tools/testing/selftests/vm/mlock-random-test.c
@@ -0,0 +1,293 @@
+/*
+ * It tests the mlock/mlock2() when they are invoked
+ * on randomly memory region.
+ */
+#include <unistd.h>
+#include <sys/resource.h>
+#include <sys/capability.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#include <time.h>
+#include "mlock2.h"
+
+#define CHUNK_UNIT (128 * 1024)
+#define MLOCK_RLIMIT_SIZE (CHUNK_UNIT * 2)
+#define MLOCK_WITHIN_LIMIT_SIZE CHUNK_UNIT
+#define MLOCK_OUTOF_LIMIT_SIZE (CHUNK_UNIT * 3)
+
+#define TEST_LOOP 100
+#define PAGE_ALIGN(size, ps) (((size) + ((ps) - 1)) & ~((ps) - 1))
+
+int set_cap_limits(rlim_t max)
+{
+ struct rlimit new;
+ cap_t cap = cap_init();
+
+ new.rlim_cur = max;
+ new.rlim_max = max;
+ if (setrlimit(RLIMIT_MEMLOCK, &new)) {
+ perror("setrlimit() returns error\n");
+ return -1;
+ }
+
+ /* drop capabilities including CAP_IPC_LOCK */
+ if (cap_set_proc(cap)) {
+ perror("cap_set_proc() returns error\n");
+ return -2;
+ }
+
+ return 0;
+}
+
+int get_proc_locked_vm_size(void)
+{
+ FILE *f;
+ int ret = -1;
+ char line[1024] = {0};
+ unsigned long lock_size = 0;
+
+ f = fopen("/proc/self/status", "r");
+ if (!f) {
+ perror("fopen");
+ return -1;
+ }
+
+ while (fgets(line, 1024, f)) {
+ if (strstr(line, "VmLck")) {
+ ret = sscanf(line, "VmLck:\t%8lu kB", &lock_size);
+ if (ret <= 0) {
+ printf("sscanf() on VmLck error: %s: %d\n",
+ line, ret);
+ fclose(f);
+ return -1;
+ }
+ fclose(f);
+ return (int)(lock_size << 10);
+ }
+ }
+
+ perror("cann't parse VmLck in /proc/self/status\n");
+ fclose(f);
+ return -1;
+}
+
+/*
+ * Get the MMUPageSize of the memory region including input
+ * address from proc file.
+ *
+ * return value: on error case, 0 will be returned.
+ * Otherwise the page size(in bytes) is returned.
+ */
+int get_proc_page_size(unsigned long addr)
+{
+ FILE *smaps;
+ char *line;
+ unsigned long mmupage_size = 0;
+ size_t size;
+
+ smaps = seek_to_smaps_entry(addr);
+ if (!smaps) {
+ printf("Unable to parse /proc/self/smaps\n");
+ return 0;
+ }
+
+ while (getline(&line, &size, smaps) > 0) {
+ if (!strstr(line, "MMUPageSize")) {
+ free(line);
+ line = NULL;
+ size = 0;
+ continue;
+ }
+
+ /* found the MMUPageSize of this section */
+ if (sscanf(line, "MMUPageSize: %8lu kB",
+ &mmupage_size) < 1) {
+ printf("Unable to parse smaps entry for Size:%s\n",
+ line);
+ break;
+ }
+
+ }
+ free(line);
+ if (smaps)
+ fclose(smaps);
+ return mmupage_size << 10;
+}
+
+/*
+ * Test mlock/mlock2() on provided memory chunk.
+ * It expects the mlock/mlock2() to be successful (within rlimit)
+ *
+ * With allocated memory chunk [p, p + alloc_size), this
+ * test will choose start/len randomly to perform mlock/mlock2
+ * [start, start + len] memory range. The range is within range
+ * of the allocated chunk.
+ *
+ * The memory region size alloc_size is within the rlimit.
+ * So we always expect a success of mlock/mlock2.
+ *
+ * VmLck is assumed to be 0 before this test.
+ *
+ * return value: 0 - success
+ * else: failure
+ */
+int test_mlock_within_limit(char *p, int alloc_size)
+{
+ int i;
+ int ret = 0;
+ int locked_vm_size = 0;
+ struct rlimit cur;
+ int page_size = 0;
+
+ getrlimit(RLIMIT_MEMLOCK, &cur);
+ if (cur.rlim_cur < alloc_size) {
+ printf("alloc_size[%d] < %u rlimit,lead to mlock failure\n",
+ alloc_size, (unsigned int)cur.rlim_cur);
+ return -1;
+ }
+
+ srand(time(NULL));
+ for (i = 0; i < TEST_LOOP; i++) {
+ /*
+ * - choose mlock/mlock2 randomly
+ * - choose lock_size randomly but lock_size < alloc_size
+ * - choose start_offset randomly but p+start_offset+lock_size
+ * < p+alloc_size
+ */
+ int is_mlock = !!(rand() % 2);
+ int lock_size = rand() % alloc_size;
+ int start_offset = rand() % (alloc_size - lock_size);
+
+ if (is_mlock)
+ ret = mlock(p + start_offset, lock_size);
+ else
+ ret = mlock2_(p + start_offset, lock_size,
+ MLOCK_ONFAULT);
+
+ if (ret) {
+ printf("%s() failure at |%p(%d)| mlock:|%p(%d)|\n",
+ is_mlock ? "mlock" : "mlock2",
+ p, alloc_size,
+ p + start_offset, lock_size);
+ return ret;
+ }
+ }
+
+ /*
+ * Check VmLck left by the tests.
+ */
+ locked_vm_size = get_proc_locked_vm_size();
+ page_size = get_proc_page_size((unsigned long)p);
+ if (page_size == 0) {
+ printf("cannot get proc MMUPageSize\n");
+ return -1;
+ }
+
+ if (locked_vm_size > PAGE_ALIGN(alloc_size, page_size) + page_size) {
+ printf("test_mlock_within_limit() left VmLck:%d on %d chunk\n",
+ locked_vm_size, alloc_size);
+ return -1;
+ }
+
+ return 0;
+}
+
+
+/*
+ * We expect the mlock/mlock2() to be fail (outof limitation)
+ *
+ * With allocated memory chunk [p, p + alloc_size), this
+ * test will randomly choose start/len and perform mlock/mlock2
+ * on [start, start+len] range.
+ *
+ * The memory region size alloc_size is above the rlimit.
+ * And the len to be locked is higher than rlimit.
+ * So we always expect a failure of mlock/mlock2.
+ * No locked page number should be increased as a side effect.
+ *
+ * return value: 0 - success
+ * else: failure
+ */
+int test_mlock_outof_limit(char *p, int alloc_size)
+{
+ int i;
+ int ret = 0;
+ int locked_vm_size = 0, old_locked_vm_size = 0;
+ struct rlimit cur;
+
+ getrlimit(RLIMIT_MEMLOCK, &cur);
+ if (cur.rlim_cur >= alloc_size) {
+ printf("alloc_size[%d] >%u rlimit, violates test condition\n",
+ alloc_size, (unsigned int)cur.rlim_cur);
+ return -1;
+ }
+
+ old_locked_vm_size = get_proc_locked_vm_size();
+ srand(time(NULL));
+ for (i = 0; i < TEST_LOOP; i++) {
+ int is_mlock = !!(rand() % 2);
+ int lock_size = (rand() % (alloc_size - cur.rlim_cur))
+ + cur.rlim_cur;
+ int start_offset = rand() % (alloc_size - lock_size);
+
+ if (is_mlock)
+ ret = mlock(p + start_offset, lock_size);
+ else
+ ret = mlock2_(p + start_offset, lock_size,
+ MLOCK_ONFAULT);
+ if (ret == 0) {
+ printf("%s() succeeds? on %p(%d) mlock%p(%d)\n",
+ is_mlock ? "mlock" : "mlock2",
+ p, alloc_size,
+ p + start_offset, lock_size);
+ return -1;
+ }
+ }
+
+ locked_vm_size = get_proc_locked_vm_size();
+ if (locked_vm_size != old_locked_vm_size) {
+ printf("tests leads to new mlocked page: old[%d], new[%d]\n",
+ old_locked_vm_size,
+ locked_vm_size);
+ return -1;
+ }
+
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ char *p = NULL;
+ int ret = 0;
+
+ if (set_cap_limits(MLOCK_RLIMIT_SIZE))
+ return -1;
+
+ p = malloc(MLOCK_WITHIN_LIMIT_SIZE);
+ if (p == NULL) {
+ perror("malloc() failure\n");
+ return -1;
+ }
+ ret = test_mlock_within_limit(p, MLOCK_WITHIN_LIMIT_SIZE);
+ if (ret)
+ return ret;
+ munlock(p, MLOCK_WITHIN_LIMIT_SIZE);
+ free(p);
+
+
+ p = malloc(MLOCK_OUTOF_LIMIT_SIZE);
+ if (p == NULL) {
+ perror("malloc() failure\n");
+ return -1;
+ }
+ ret = test_mlock_outof_limit(p, MLOCK_OUTOF_LIMIT_SIZE);
+ if (ret)
+ return ret;
+ munlock(p, MLOCK_OUTOF_LIMIT_SIZE);
+ free(p);
+
+ return 0;
+}
--
1.8.3.1
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