/*
* libhugetlbfs - Easy use of Linux hugepages
* Copyright (C) 2005-2006 David Gibson & Adam Litke, IBM Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <sys/mman.h>
#include <setjmp.h>
#include <hugetlbfs.h>
#include "hugetests.h"
/*
* Test rationale:
*
* At one stage, improper handling of tests against i_size could mess
* up accounting of reserved hugepages on certain truncate
* operations.
*
* This bug was fixed with a band-aid (enough to pass this test) in
* commit ebed4bfc8da8df5b6b0bc4a5064a949f04683509. A more complete
* fix still pending as of 3d4248885b9fca818e7fe6b66328e714876d36ad.
*/
#define RANDOM_CONSTANT 0x1234ABCD
static sigjmp_buf sig_escape;
static void sigbus_handler(int signum, siginfo_t *si, void *uc)
{
siglongjmp(sig_escape, 17);
}
int main(int argc, char *argv[])
{
long hpage_size;
int fd;
void *p;
volatile unsigned int *q;
int err;
int sigbus_count = 0;
unsigned long initial_rsvd, rsvd;
struct sigaction sa = {
.sa_sigaction = sigbus_handler,
.sa_flags = SA_SIGINFO,
};
test_init(argc, argv);
hpage_size = check_hugepagesize();
fd = hugetlbfs_unlinked_fd();
if (fd < 0)
FAIL("hugetlbfs_unlinked_fd()");
initial_rsvd = get_huge_page_counter(hpage_size, HUGEPAGES_RSVD);
verbose_printf("Reserve count before map: %lu\n", initial_rsvd);
p = mmap(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_SHARED,
fd, 0);
if (p == MAP_FAILED)
FAIL("mmap(): %s", strerror(errno));
q = p;
verbose_printf("Reserve count after map: %lu\n",
get_huge_page_counter(hpage_size, HUGEPAGES_RSVD));
*q = 0;
verbose_printf("Reserve count after touch: %lu\n",
get_huge_page_counter(hpage_size, HUGEPAGES_RSVD));
err = ftruncate(fd, 0);
if (err)
FAIL("ftruncate(): %s", strerror(errno));
rsvd = get_huge_page_counter(hpage_size, HUGEPAGES_RSVD);
verbose_printf("Reserve count after truncate: %lu\n", rsvd);
if (rsvd != initial_rsvd)
FAIL("Reserved count is not restored after truncate: %lu instead of %lu",
rsvd, initial_rsvd);
err = sigaction(SIGBUS, &sa, NULL);
if (err)
FAIL("sigaction(): %s", strerror(errno));
if (sigsetjmp(sig_escape, 1) == 0)
*q; /* Fault, triggering a SIGBUS */
else
sigbus_count++;
if (sigbus_count != 1)
FAIL("Didn't SIGBUS after truncate");
rsvd = get_huge_page_counter(hpage_size, HUGEPAGES_RSVD);
verbose_printf("Reserve count after SIGBUS fault: %lu\n", rsvd);
if (rsvd != initial_rsvd)
FAIL("Reserved count is altered by SIGBUS fault: %lu instead of %lu",
rsvd, initial_rsvd);
munmap(p, hpage_size);
verbose_printf("Reserve count after munmap(): %lu\n",
get_huge_page_counter(hpage_size, HUGEPAGES_RSVD));
close(fd);
verbose_printf("Reserve count after close(): %lu\n",
get_huge_page_counter(hpage_size, HUGEPAGES_RSVD));
PASS();
}