blob: 02ca5e0177c539c79b3fbb53d31ed3da7e4ba9a4 [file] [log] [blame]
#define _GNU_SOURCE
#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 0x8000000000000000ULL
#define PFN_MASK 0x007FFFFFFFFFFFFFULL
#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;
}