diff options
Diffstat (limited to 'vm/mlock2-tests.c')
| -rw-r--r-- | vm/mlock2-tests.c | 737 |
1 files changed, 737 insertions, 0 deletions
diff --git a/vm/mlock2-tests.c b/vm/mlock2-tests.c new file mode 100644 index 0000000..02ca5e0 --- /dev/null +++ b/vm/mlock2-tests.c @@ -0,0 +1,737 @@ +#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; +} |