unplugged-system/external/ltp/testcases/kernel/mem/hugetlb/hugemmap/hugemmap12.c

84 lines
2.0 KiB
C

// SPDX-License-Identifier: LGPL-2.1-or-later
/*
* Copyright (C) 2005-2006 IBM Corporation.
* Author: Mel Gorman
*/
/*\
* [Description]
*
* fadvise() on some kernels can cause the reservation counter to get
* corrupted. The problem is that the patches are allocated for the
* reservation but not faulted in at the time of allocation. The counters
* do not get updated and effectively "leak". This test identifies whether
* the kernel is vulnerable to the problem or not. It's fixed in kernel
* by commit f2deae9d4e70793568ef9e85d227abb7bef5b622.
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <sys/mount.h>
#include <limits.h>
#include <sys/param.h>
#include <sys/types.h>
#include "hugetlb.h"
#define MNTPOINT "hugetlbfs/"
static long hpage_size;
static int fd = -1;
static void run_test(void)
{
void *p;
unsigned long initial_rsvd, map_rsvd, fadvise_rsvd, end_rsvd;
fd = tst_creat_unlinked(MNTPOINT, 0);
initial_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
tst_res(TINFO, "Reserve count before map: %lu", initial_rsvd);
p = SAFE_MMAP(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_SHARED,
fd, 0);
map_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
tst_res(TINFO, "Reserve count after map: %lu", map_rsvd);
SAFE_POSIX_FADVISE(fd, 0, hpage_size, POSIX_FADV_WILLNEED);
fadvise_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
tst_res(TINFO, "Reserve count after fadvise: %lu", fadvise_rsvd);
memset(p, 1, hpage_size);
SAFE_MUNMAP(p, hpage_size);
SAFE_CLOSE(fd);
end_rsvd = SAFE_READ_MEMINFO(MEMINFO_HPAGE_RSVD);
tst_res(TINFO, "Reserve count after close: %lu", end_rsvd);
TST_EXP_EQ_LU(end_rsvd, initial_rsvd);
}
static void setup(void)
{
hpage_size = SAFE_READ_MEMINFO(MEMINFO_HPAGE_SIZE)*1024;
}
static void cleanup(void)
{
if (fd > 0)
SAFE_CLOSE(fd);
}
static struct tst_test test = {
.tags = (struct tst_tag[]) {
{"linux-git", "f2deae9d4e70"},
{}
},
.needs_root = 1,
.mntpoint = MNTPOINT,
.needs_hugetlbfs = 1,
.setup = setup,
.cleanup = cleanup,
.test_all = run_test,
.hugepages = {1, TST_NEEDS},
};