Commit b3b0d09c authored by Eric B Munson's avatar Eric B Munson Committed by Linus Torvalds
Browse files

selftests: vm: add tests for lock on fault 



Test the mmap() flag, and the mlockall() flag.  These tests ensure that
pages are not faulted in until they are accessed, that the pages are
unevictable once faulted in, and that VMA splitting and merging works with
the new VM flag.  The second test ensures that mlock limits are respected.
 Note that the limit test needs to be run a normal user.

Also add tests to use the new mlock2 family of system calls.

[treding@nvidia.com: : Fix mlock2-tests for 32-bit architectures]
[treding@nvidia.com: ensure the mlock2 syscall number can be found]
[treding@nvidia.com: use the right arguments for main()]
Signed-off-by: default avatarEric B Munson <emunson@akamai.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b0f205c2

tools/testing/selftests/vm/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -5,6 +5,8 @@ BINARIES = compaction_test 
BINARIES += hugepage-mmap

BINARIES += hugepage-shm

BINARIES += map_hugetlb

BINARIES += mlock2-tests

BINARIES += on-fault-limit

BINARIES += thuge-gen

BINARIES += transhuge-stress

BINARIES += userfaultfd

tools/testing/selftests/vm/mlock2-tests.c

0 → 100644
+736 −0
Original line number Diff line number Diff line 
#include <sys/mman.h>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <string.h>

#include <sys/time.h>

#include <sys/resource.h>

#include <syscall.h>

#include <errno.h>

#include <stdbool.h>



#ifndef MLOCK_ONFAULT

#define MLOCK_ONFAULT 1

#endif



#ifndef MCL_ONFAULT

#define MCL_ONFAULT (MCL_FUTURE << 1)

#endif



static int mlock2_(void *start, size_t len, int flags)

{

#ifdef __NR_mlock2

	return syscall(__NR_mlock2, start, len, flags);

#else

	errno = ENOSYS;

	return -1;

#endif

}



struct vm_boundaries {

	unsigned long start;

	unsigned long end;

};



static int get_vm_area(unsigned long addr, struct vm_boundaries *area)

{

	FILE *file;

	int ret = 1;

	char line[1024] = {0};

	char *end_addr;

	char *stop;

	unsigned long start;

	unsigned long end;



	if (!area)

		return ret;



	file = fopen("/proc/self/maps", "r");

	if (!file) {

		perror("fopen");

		return ret;

	}



	memset(area, 0, sizeof(struct vm_boundaries));



	while(fgets(line, 1024, file)) {

		end_addr = strchr(line, '-');

		if (!end_addr) {

			printf("cannot parse /proc/self/maps\n");

			goto out;

		}

		*end_addr = '\0';

		end_addr++;

		stop = strchr(end_addr, ' ');

		if (!stop) {

			printf("cannot parse /proc/self/maps\n");

			goto out;

		}

		stop = '\0';



		sscanf(line, "%lx", &start);

		sscanf(end_addr, "%lx", &end);



		if (start <= addr && end > addr) {

			area->start = start;

			area->end = end;

			ret = 0;

			goto out;

		}

	}

out:

	fclose(file);

	return ret;

}



static uint64_t get_pageflags(unsigned long addr)

{

	FILE *file;

	uint64_t pfn;

	unsigned long offset;



	file = fopen("/proc/self/pagemap", "r");

	if (!file) {

		perror("fopen pagemap");

		_exit(1);

	}



	offset = addr / getpagesize() * sizeof(pfn);



	if (fseek(file, offset, SEEK_SET)) {

		perror("fseek pagemap");

		_exit(1);

	}



	if (fread(&pfn, sizeof(pfn), 1, file) != 1) {

		perror("fread pagemap");

		_exit(1);

	}



	fclose(file);

	return pfn;

}



static uint64_t get_kpageflags(unsigned long pfn)

{

	uint64_t flags;

	FILE *file;



	file = fopen("/proc/kpageflags", "r");

	if (!file) {

		perror("fopen kpageflags");

		_exit(1);

	}



	if (fseek(file, pfn * sizeof(flags), SEEK_SET)) {

		perror("fseek kpageflags");

		_exit(1);

	}



	if (fread(&flags, sizeof(flags), 1, file) != 1) {

		perror("fread kpageflags");

		_exit(1);

	}



	fclose(file);

	return flags;

}



static FILE *seek_to_smaps_entry(unsigned long addr)

{

	FILE *file;

	char *line = NULL;

	size_t size = 0;

	unsigned long start, end;

	char perms[5];

	unsigned long offset;

	char dev[32];

	unsigned long inode;

	char path[BUFSIZ];



	file = fopen("/proc/self/smaps", "r");

	if (!file) {

		perror("fopen smaps");

		_exit(1);

	}



	while (getline(&line, &size, file) > 0) {

		if (sscanf(line, "%lx-%lx %s %lx %s %lu %s\n",

			   &start, &end, perms, &offset, dev, &inode, path) < 6)

			goto next;



		if (start <= addr && addr < end)

			goto out;



next:

		free(line);

		line = NULL;

		size = 0;

	}



	fclose(file);

	file = NULL;



out:

	free(line);

	return file;

}



#define VMFLAGS "VmFlags:"



static bool is_vmflag_set(unsigned long addr, const char *vmflag)

{

	char *line = NULL;

	char *flags;

	size_t size = 0;

	bool ret = false;

	FILE *smaps;



	smaps = seek_to_smaps_entry(addr);

	if (!smaps) {

		printf("Unable to parse /proc/self/smaps\n");

		goto out;

	}



	while (getline(&line, &size, smaps) > 0) {

		if (!strstr(line, VMFLAGS)) {

			free(line);

			line = NULL;

			size = 0;

			continue;

		}



		flags = line + strlen(VMFLAGS);

		ret = (strstr(flags, vmflag) != NULL);

		goto out;

	}



out:

	free(line);

	fclose(smaps);

	return ret;

}



#define SIZE "Size:"

#define RSS  "Rss:"

#define LOCKED "lo"



static bool is_vma_lock_on_fault(unsigned long addr)

{

	bool ret = false;

	bool locked;

	FILE *smaps = NULL;

	unsigned long vma_size, vma_rss;

	char *line = NULL;

	char *value;

	size_t size = 0;



	locked = is_vmflag_set(addr, LOCKED);

	if (!locked)

		goto out;



	smaps = seek_to_smaps_entry(addr);

	if (!smaps) {

		printf("Unable to parse /proc/self/smaps\n");

		goto out;

	}



	while (getline(&line, &size, smaps) > 0) {

		if (!strstr(line, SIZE)) {

			free(line);

			line = NULL;

			size = 0;

			continue;

		}



		value = line + strlen(SIZE);

		if (sscanf(value, "%lu kB", &vma_size) < 1) {

			printf("Unable to parse smaps entry for Size\n");

			goto out;

		}

		break;

	}



	while (getline(&line, &size, smaps) > 0) {

		if (!strstr(line, RSS)) {

			free(line);

			line = NULL;

			size = 0;

			continue;

		}



		value = line + strlen(RSS);

		if (sscanf(value, "%lu kB", &vma_rss) < 1) {

			printf("Unable to parse smaps entry for Rss\n");

			goto out;

		}

		break;

	}



	ret = locked && (vma_rss < vma_size);

out:

	free(line);

	if (smaps)

		fclose(smaps);

	return ret;

}



#define PRESENT_BIT     0x8000000000000000

#define PFN_MASK        0x007FFFFFFFFFFFFF

#define UNEVICTABLE_BIT (1UL << 18)



static int lock_check(char *map)

{

	unsigned long page_size = getpagesize();

	uint64_t page1_flags, page2_flags;



	page1_flags = get_pageflags((unsigned long)map);

	page2_flags = get_pageflags((unsigned long)map + page_size);



	/* Both pages should be present */

	if (((page1_flags & PRESENT_BIT) == 0) ||

	    ((page2_flags & PRESENT_BIT) == 0)) {

		printf("Failed to make both pages present\n");

		return 1;

	}



	page1_flags = get_kpageflags(page1_flags & PFN_MASK);

	page2_flags = get_kpageflags(page2_flags & PFN_MASK);



	/* Both pages should be unevictable */

	if (((page1_flags & UNEVICTABLE_BIT) == 0) ||

	    ((page2_flags & UNEVICTABLE_BIT) == 0)) {

		printf("Failed to make both pages unevictable\n");

		return 1;

	}



	if (!is_vmflag_set((unsigned long)map, LOCKED)) {

		printf("VMA flag %s is missing on page 1\n", LOCKED);

		return 1;

	}



	if (!is_vmflag_set((unsigned long)map + page_size, LOCKED)) {

		printf("VMA flag %s is missing on page 2\n", LOCKED);

		return 1;

	}



	return 0;

}



static int unlock_lock_check(char *map)

{

	unsigned long page_size = getpagesize();

	uint64_t page1_flags, page2_flags;



	page1_flags = get_pageflags((unsigned long)map);

	page2_flags = get_pageflags((unsigned long)map + page_size);

	page1_flags = get_kpageflags(page1_flags & PFN_MASK);

	page2_flags = get_kpageflags(page2_flags & PFN_MASK);



	if ((page1_flags & UNEVICTABLE_BIT) || (page2_flags & UNEVICTABLE_BIT)) {

		printf("A page is still marked unevictable after unlock\n");

		return 1;

	}



	if (is_vmflag_set((unsigned long)map, LOCKED)) {

		printf("VMA flag %s is present on page 1 after unlock\n", LOCKED);

		return 1;

	}



	if (is_vmflag_set((unsigned long)map + page_size, LOCKED)) {

		printf("VMA flag %s is present on page 2 after unlock\n", LOCKED);

		return 1;

	}



	return 0;

}



static int test_mlock_lock()

{

	char *map;

	int ret = 1;

	unsigned long page_size = getpagesize();



	map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,

		   MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);

	if (map == MAP_FAILED) {

		perror("test_mlock_locked mmap");

		goto out;

	}



	if (mlock2_(map, 2 * page_size, 0)) {

		if (errno == ENOSYS) {

			printf("Cannot call new mlock family, skipping test\n");

			_exit(0);

		}

		perror("mlock2(0)");

		goto unmap;

	}



	if (lock_check(map))

		goto unmap;



	/* Now unlock and recheck attributes */

	if (munlock(map, 2 * page_size)) {

		perror("munlock()");

		goto unmap;

	}



	ret = unlock_lock_check(map);



unmap:

	munmap(map, 2 * page_size);

out:

	return ret;

}



static int onfault_check(char *map)

{

	unsigned long page_size = getpagesize();

	uint64_t page1_flags, page2_flags;



	page1_flags = get_pageflags((unsigned long)map);

	page2_flags = get_pageflags((unsigned long)map + page_size);



	/* Neither page should be present */

	if ((page1_flags & PRESENT_BIT) || (page2_flags & PRESENT_BIT)) {

		printf("Pages were made present by MLOCK_ONFAULT\n");

		return 1;

	}



	*map = 'a';

	page1_flags = get_pageflags((unsigned long)map);

	page2_flags = get_pageflags((unsigned long)map + page_size);



	/* Only page 1 should be present */

	if ((page1_flags & PRESENT_BIT) == 0) {

		printf("Page 1 is not present after fault\n");

		return 1;

	} else if (page2_flags & PRESENT_BIT) {

		printf("Page 2 was made present\n");

		return 1;

	}



	page1_flags = get_kpageflags(page1_flags & PFN_MASK);



	/* Page 1 should be unevictable */

	if ((page1_flags & UNEVICTABLE_BIT) == 0) {

		printf("Failed to make faulted page unevictable\n");

		return 1;

	}



	if (!is_vma_lock_on_fault((unsigned long)map)) {

		printf("VMA is not marked for lock on fault\n");

		return 1;

	}



	if (!is_vma_lock_on_fault((unsigned long)map + page_size)) {

		printf("VMA is not marked for lock on fault\n");

		return 1;

	}



	return 0;

}



static int unlock_onfault_check(char *map)

{

	unsigned long page_size = getpagesize();

	uint64_t page1_flags;



	page1_flags = get_pageflags((unsigned long)map);

	page1_flags = get_kpageflags(page1_flags & PFN_MASK);



	if (page1_flags & UNEVICTABLE_BIT) {

		printf("Page 1 is still marked unevictable after unlock\n");

		return 1;

	}



	if (is_vma_lock_on_fault((unsigned long)map) ||

	    is_vma_lock_on_fault((unsigned long)map + page_size)) {

		printf("VMA is still lock on fault after unlock\n");

		return 1;

	}



	return 0;

}



static int test_mlock_onfault()

{

	char *map;

	int ret = 1;

	unsigned long page_size = getpagesize();



	map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,

		   MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);

	if (map == MAP_FAILED) {

		perror("test_mlock_locked mmap");

		goto out;

	}



	if (mlock2_(map, 2 * page_size, MLOCK_ONFAULT)) {

		if (errno == ENOSYS) {

			printf("Cannot call new mlock family, skipping test\n");

			_exit(0);

		}

		perror("mlock2(MLOCK_ONFAULT)");

		goto unmap;

	}



	if (onfault_check(map))

		goto unmap;



	/* Now unlock and recheck attributes */

	if (munlock(map, 2 * page_size)) {

		if (errno == ENOSYS) {

			printf("Cannot call new mlock family, skipping test\n");

			_exit(0);

		}

		perror("munlock()");

		goto unmap;

	}



	ret = unlock_onfault_check(map);

unmap:

	munmap(map, 2 * page_size);

out:

	return ret;

}



static int test_lock_onfault_of_present()

{

	char *map;

	int ret = 1;

	unsigned long page_size = getpagesize();

	uint64_t page1_flags, page2_flags;



	map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,

		   MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);

	if (map == MAP_FAILED) {

		perror("test_mlock_locked mmap");

		goto out;

	}



	*map = 'a';



	if (mlock2_(map, 2 * page_size, MLOCK_ONFAULT)) {

		if (errno == ENOSYS) {

			printf("Cannot call new mlock family, skipping test\n");

			_exit(0);

		}

		perror("mlock2(MLOCK_ONFAULT)");

		goto unmap;

	}



	page1_flags = get_pageflags((unsigned long)map);

	page2_flags = get_pageflags((unsigned long)map + page_size);

	page1_flags = get_kpageflags(page1_flags & PFN_MASK);

	page2_flags = get_kpageflags(page2_flags & PFN_MASK);



	/* Page 1 should be unevictable */

	if ((page1_flags & UNEVICTABLE_BIT) == 0) {

		printf("Failed to make present page unevictable\n");

		goto unmap;

	}



	if (!is_vma_lock_on_fault((unsigned long)map) ||

	    !is_vma_lock_on_fault((unsigned long)map + page_size)) {

		printf("VMA with present pages is not marked lock on fault\n");

		goto unmap;

	}

	ret = 0;

unmap:

	munmap(map, 2 * page_size);

out:

	return ret;

}



static int test_munlockall()

{

	char *map;

	int ret = 1;

	unsigned long page_size = getpagesize();



	map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,

		   MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);



	if (map == MAP_FAILED) {

		perror("test_munlockall mmap");

		goto out;

	}



	if (mlockall(MCL_CURRENT)) {

		perror("mlockall(MCL_CURRENT)");

		goto out;

	}



	if (lock_check(map))

		goto unmap;



	if (munlockall()) {

		perror("munlockall()");

		goto unmap;

	}



	if (unlock_lock_check(map))

		goto unmap;



	munmap(map, 2 * page_size);



	map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,

		   MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);



	if (map == MAP_FAILED) {

		perror("test_munlockall second mmap");

		goto out;

	}



	if (mlockall(MCL_CURRENT | MCL_ONFAULT)) {

		perror("mlockall(MCL_CURRENT | MCL_ONFAULT)");

		goto unmap;

	}



	if (onfault_check(map))

		goto unmap;



	if (munlockall()) {

		perror("munlockall()");

		goto unmap;

	}



	if (unlock_onfault_check(map))

		goto unmap;



	if (mlockall(MCL_CURRENT | MCL_FUTURE)) {

		perror("mlockall(MCL_CURRENT | MCL_FUTURE)");

		goto out;

	}



	if (lock_check(map))

		goto unmap;



	if (munlockall()) {

		perror("munlockall()");

		goto unmap;

	}



	ret = unlock_lock_check(map);



unmap:

	munmap(map, 2 * page_size);

out:

	munlockall();

	return ret;

}



static int test_vma_management(bool call_mlock)

{

	int ret = 1;

	void *map;

	unsigned long page_size = getpagesize();

	struct vm_boundaries page1;

	struct vm_boundaries page2;

	struct vm_boundaries page3;



	map = mmap(NULL, 3 * page_size, PROT_READ | PROT_WRITE,

		   MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);

	if (map == MAP_FAILED) {

		perror("mmap()");

		return ret;

	}



	if (call_mlock && mlock2_(map, 3 * page_size, MLOCK_ONFAULT)) {

		if (errno == ENOSYS) {

			printf("Cannot call new mlock family, skipping test\n");

			_exit(0);

		}

		perror("mlock(ONFAULT)\n");

		goto out;

	}



	if (get_vm_area((unsigned long)map, &page1) ||

	    get_vm_area((unsigned long)map + page_size, &page2) ||

	    get_vm_area((unsigned long)map + page_size * 2, &page3)) {

		printf("couldn't find mapping in /proc/self/maps\n");

		goto out;

	}



	/*

	 * Before we unlock a portion, we need to that all three pages are in

	 * the same VMA.  If they are not we abort this test (Note that this is

	 * not a failure)

	 */

	if (page1.start != page2.start || page2.start != page3.start) {

		printf("VMAs are not merged to start, aborting test\n");

		ret = 0;

		goto out;

	}



	if (munlock(map + page_size, page_size)) {

		perror("munlock()");

		goto out;

	}



	if (get_vm_area((unsigned long)map, &page1) ||

	    get_vm_area((unsigned long)map + page_size, &page2) ||

	    get_vm_area((unsigned long)map + page_size * 2, &page3)) {

		printf("couldn't find mapping in /proc/self/maps\n");

		goto out;

	}



	/* All three VMAs should be different */

	if (page1.start == page2.start || page2.start == page3.start) {

		printf("failed to split VMA for munlock\n");

		goto out;

	}



	/* Now unlock the first and third page and check the VMAs again */

	if (munlock(map, page_size * 3)) {

		perror("munlock()");

		goto out;

	}



	if (get_vm_area((unsigned long)map, &page1) ||

	    get_vm_area((unsigned long)map + page_size, &page2) ||

	    get_vm_area((unsigned long)map + page_size * 2, &page3)) {

		printf("couldn't find mapping in /proc/self/maps\n");

		goto out;

	}



	/* Now all three VMAs should be the same */

	if (page1.start != page2.start || page2.start != page3.start) {

		printf("failed to merge VMAs after munlock\n");

		goto out;

	}



	ret = 0;

out:

	munmap(map, 3 * page_size);

	return ret;

}



static int test_mlockall(int (test_function)(bool call_mlock))

{

	int ret = 1;



	if (mlockall(MCL_CURRENT | MCL_ONFAULT | MCL_FUTURE)) {

		perror("mlockall");

		return ret;

	}



	ret = test_function(false);

	munlockall();

	return ret;

}



int main(int argc, char **argv)

{

	int ret = 0;

	ret += test_mlock_lock();

	ret += test_mlock_onfault();

	ret += test_munlockall();

	ret += test_lock_onfault_of_present();

	ret += test_vma_management(true);

	ret += test_mlockall(test_vma_management);

	return ret;

}

tools/testing/selftests/vm/on-fault-limit.c

0 → 100644
+47 −0
Original line number Diff line number Diff line 
#include <sys/mman.h>

#include <stdio.h>

#include <unistd.h>

#include <string.h>

#include <sys/time.h>

#include <sys/resource.h>



#ifndef MCL_ONFAULT

#define MCL_ONFAULT (MCL_FUTURE << 1)

#endif



static int test_limit(void)

{

	int ret = 1;

	struct rlimit lims;

	void *map;



	if (getrlimit(RLIMIT_MEMLOCK, &lims)) {

		perror("getrlimit");

		return ret;

	}



	if (mlockall(MCL_CURRENT | MCL_ONFAULT | MCL_FUTURE)) {

		perror("mlockall");

		return ret;

	}



	map = mmap(NULL, 2 * lims.rlim_max, PROT_READ | PROT_WRITE,

		   MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, 0, 0);

	if (map != MAP_FAILED)

		printf("mmap should have failed, but didn't\n");

	else {

		ret = 0;

		munmap(map, 2 * lims.rlim_max);

	}



	munlockall();

	return ret;

}



int main(int argc, char **argv)

{

	int ret = 0;



	ret += test_limit();

	return ret;

}

tools/testing/selftests/vm/run_vmtests

+22 −0
Original line number Diff line number Diff line
@@ -106,4 +106,26 @@ else 
	echo "[PASS]"

fi



echo "--------------------"

echo "running on-fault-limit"

echo "--------------------"

sudo -u nobody ./on-fault-limit

if [ $? -ne 0 ]; then

	echo "[FAIL]"

	exitcode=1

else

	echo "[PASS]"

fi



echo "--------------------"

echo "running mlock2-tests"

echo "--------------------"

./mlock2-tests

if [ $? -ne 0 ]; then

	echo "[FAIL]"

	exitcode=1

else

	echo "[PASS]"

fi



exit $exitcode

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