Contributors: 12
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Mina Almasry |
459 |
57.38% |
1 |
6.25% |
| Muhammad Usama Anjum |
80 |
10.00% |
2 |
12.50% |
| Mike Rapoport |
65 |
8.12% |
2 |
12.50% |
| Yosry Ahmed |
57 |
7.12% |
1 |
6.25% |
| Peter Xu |
39 |
4.88% |
2 |
12.50% |
| Aboorva Devarajan |
29 |
3.62% |
1 |
6.25% |
| Mike Kravetz |
28 |
3.50% |
1 |
6.25% |
| Niels Dossche |
26 |
3.25% |
1 |
6.25% |
| Sayali Patil |
12 |
1.50% |
2 |
12.50% |
| Zi Yan |
3 |
0.38% |
1 |
6.25% |
| John Hubbard |
1 |
0.12% |
1 |
6.25% |
| Bala-Vignesh-Reddy |
1 |
0.12% |
1 |
6.25% |
| Total |
800 |
|
16 |
|
// SPDX-License-Identifier: GPL-2.0
/*
* hugetlb-mremap:
*
* Example of remapping huge page memory in a user application using the
* mremap system call. The path to a file in a hugetlbfs filesystem must
* be passed as the last argument to this test. The amount of memory used
* by this test in MBs can optionally be passed as an argument. If no memory
* amount is passed, the default amount is 10MB.
*
* To make sure the test triggers pmd sharing and goes through the 'unshare'
* path in the mremap code use 1GB (1024) or more.
*/
#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>
#include <errno.h>
#include <fcntl.h> /* Definition of O_* constants */
#include <sys/syscall.h> /* Definition of SYS_* constants */
#include <linux/userfaultfd.h>
#include <sys/ioctl.h>
#include <string.h>
#include <stdbool.h>
#include "kselftest.h"
#include "vm_util.h"
#include "hugepage_settings.h"
#define DEFAULT_LENGTH_MB 10UL
#define MB_TO_BYTES(x) (x * 1024 * 1024)
#define PROTECTION (PROT_READ | PROT_WRITE | PROT_EXEC)
#define FLAGS (MAP_HUGETLB | MAP_SHARED)
static void check_bytes(char *addr)
{
ksft_print_msg("First hex is %x\n", *((unsigned int *)addr));
}
static void write_bytes(char *addr, size_t len)
{
unsigned long i;
for (i = 0; i < len; i++)
*(addr + i) = (char)i;
}
static int read_bytes(char *addr, size_t len)
{
unsigned long i;
check_bytes(addr);
for (i = 0; i < len; i++)
if (*(addr + i) != (char)i) {
ksft_print_msg("Mismatch at %lu\n", i);
return 1;
}
return 0;
}
static void register_region_with_uffd(char *addr, size_t len)
{
long uffd; /* userfaultfd file descriptor */
struct uffdio_api uffdio_api;
/* Create and enable userfaultfd object. */
uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
if (uffd == -1) {
switch (errno) {
case EPERM:
ksft_exit_skip("Insufficient permissions, try running as root.\n");
break;
case ENOSYS:
ksft_exit_skip("userfaultfd is not supported/not enabled.\n");
break;
default:
ksft_exit_fail_msg("userfaultfd failed with %s\n", strerror(errno));
break;
}
}
uffdio_api.api = UFFD_API;
uffdio_api.features = 0;
if (ioctl(uffd, UFFDIO_API, &uffdio_api) == -1)
ksft_exit_fail_msg("ioctl-UFFDIO_API: %s\n", strerror(errno));
/* Register the passed memory range for handling by the userfaultfd object.
* In mode, we request to track missing pages
* (i.e., pages that have not yet been faulted in).
*/
if (uffd_register(uffd, addr, len, true, false, false))
ksft_exit_fail_msg("ioctl-UFFDIO_REGISTER: %s\n", strerror(errno));
ksft_print_msg("Registered memory at address %p with userfaultfd\n", addr);
}
int main(int argc, char *argv[])
{
unsigned long hugepage_size;
int ret = 0, fd, nr;
size_t length = 0;
ksft_print_header();
ksft_set_plan(1);
if (argc >= 2 && !strcmp(argv[1], "-h"))
ksft_exit_fail_msg("Usage: %s [length_in_MB]\n", argv[0]);
/* Read memory length as the first arg if valid, otherwise fallback to
* the default length.
*/
if (argc >= 2)
length = (size_t)atoi(argv[1]);
else
length = DEFAULT_LENGTH_MB;
hugepage_size = default_huge_page_size();
if (!hugepage_size)
ksft_exit_skip("Could not detect default hugetlb page size\n");
length = MB_TO_BYTES(length);
length = (length + hugepage_size - 1) & ~(hugepage_size - 1);
nr = length / hugepage_size;
if (!hugetlb_setup_default(nr))
ksft_exit_skip("Not enough huge pages\n");
fd = memfd_create(argv[0], MFD_HUGETLB);
if (fd < 0)
ksft_exit_fail_msg("Open failed: %s\n", strerror(errno));
/* mmap to a PUD aligned address to hopefully trigger pmd sharing. */
unsigned long suggested_addr = 0x7eaa40000000;
void *haddr = mmap((void *)suggested_addr, length, PROTECTION, FLAGS, fd, 0);
ksft_print_msg("Map haddr: Returned address is %p\n", haddr);
if (haddr == MAP_FAILED)
ksft_exit_fail_msg("mmap1: %s\n", strerror(errno));
/* mmap again to a dummy address to hopefully trigger pmd sharing. */
suggested_addr = 0x7daa40000000;
void *daddr = mmap((void *)suggested_addr, length, PROTECTION, FLAGS, fd, 0);
ksft_print_msg("Map daddr: Returned address is %p\n", daddr);
if (daddr == MAP_FAILED)
ksft_exit_fail_msg("mmap3: %s\n", strerror(errno));
suggested_addr = 0x7faa40000000;
void *vaddr = mmap((void *)suggested_addr, length, PROTECTION, FLAGS, fd, 0);
ksft_print_msg("Map vaddr: Returned address is %p\n", vaddr);
if (vaddr == MAP_FAILED)
ksft_exit_fail_msg("mmap2: %s\n", strerror(errno));
register_region_with_uffd(haddr, length);
void *addr = mremap(haddr, length, length,
MREMAP_MAYMOVE | MREMAP_FIXED, vaddr);
if (addr == MAP_FAILED)
ksft_exit_fail_msg("mremap: %s\n", strerror(errno));
ksft_print_msg("Mremap: Returned address is %p\n", addr);
check_bytes(addr);
write_bytes(addr, length);
ret = read_bytes(addr, length);
munmap(addr, length);
addr = mremap(addr, length, length, 0);
if (addr != MAP_FAILED)
ksft_exit_fail_msg("mremap: Expected failure, but call succeeded\n");
close(fd);
ksft_test_result(!ret, "Read same data\n");
ksft_exit(!ret);
}