[LTP] [PATCH] hugetlb: add new testcase hugeshmat05.c
Alexey Kodanev
alexey.kodanev@oracle.com
Fri Dec 4 17:28:36 CET 2015
Hi,
On 11/27/2015 01:24 PM, Li Wang wrote:
> shmget()/shmat() fails to allocate huge pages shared memory segment
> with EINVAL if its size is not in the range [ N*HUGE_PAGE_SIZE - 4095,
> N*HUGE_PAGE_SIZE ]. This is a problem in the memory segment size round
> up algorithm. The requested size is rounded up to PAGE_SIZE (4096), but
> if this roundup does not match HUGE_PAGE_SIZE (2Mb) boundary - the
> allocation fails.
>
> This bug is present in all RHEL6 versions, but not in RHEL7. It looks
> like this was fixed in mainstream kernel > v3.3 by the following patches:
>
> 091d0d5 shm: fix null pointer deref when userspace specifies invalid hugepage size
> af73e4d hugetlbfs: fix mmap failure in unaligned size request
> 42d7395 mm: support more pagesizes for MAP_HUGETLB/SHM_HUGETLB
> 40716e2 hugetlbfs: fix alignment of huge page requests
>
> Signed-off-by: Li Wang <liwang@redhat.com>
> ---
> runtest/hugetlb | 1 +
> testcases/kernel/mem/.gitignore | 1 +
> .../kernel/mem/hugetlb/hugeshmat/hugeshmat05.c | 140 +++++++++++++++++++++
> 3 files changed, 142 insertions(+)
> create mode 100644 testcases/kernel/mem/hugetlb/hugeshmat/hugeshmat05.c
>
> diff --git a/runtest/hugetlb b/runtest/hugetlb
> index 2e9f215..75e6426 100644
> --- a/runtest/hugetlb
> +++ b/runtest/hugetlb
> @@ -10,6 +10,7 @@ hugeshmat01 hugeshmat01 -i 5
> hugeshmat02 hugeshmat02 -i 5
> hugeshmat03 hugeshmat03 -i 5
> hugeshmat04 hugeshmat04 -i 5
> +hugeshmat05 hugeshmat05 -i 5
>
> hugeshmctl01 hugeshmctl01 -i 5
> hugeshmctl02 hugeshmctl02 -i 5
> diff --git a/testcases/kernel/mem/.gitignore b/testcases/kernel/mem/.gitignore
> index 4702377..46c2432 100644
> --- a/testcases/kernel/mem/.gitignore
> +++ b/testcases/kernel/mem/.gitignore
> @@ -7,6 +7,7 @@
> /hugetlb/hugeshmat/hugeshmat02
> /hugetlb/hugeshmat/hugeshmat03
> /hugetlb/hugeshmat/hugeshmat04
> +/hugetlb/hugeshmat/hugeshmat05
> /hugetlb/hugeshmctl/hugeshmctl01
> /hugetlb/hugeshmctl/hugeshmctl02
> /hugetlb/hugeshmctl/hugeshmctl03
> diff --git a/testcases/kernel/mem/hugetlb/hugeshmat/hugeshmat05.c b/testcases/kernel/mem/hugetlb/hugeshmat/hugeshmat05.c
> new file mode 100644
> index 0000000..f7cbc93
> --- /dev/null
> +++ b/testcases/kernel/mem/hugetlb/hugeshmat/hugeshmat05.c
> @@ -0,0 +1,140 @@
> +/*
> + * Copyright (c) 2015 Red Hat, Inc.
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, either version 3 of the License, or
> + * (at your option) any later version.
> + *
> + * This program 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 General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +/*
> + * DESCRIPTION
> + * shmget()/shmat() fails to allocate huge pages shared memory segment
> + * with EINVAL if its size is not in the range [ N*HUGE_PAGE_SIZE - 4095,
> + * N*HUGE_PAGE_SIZE ]. This is a problem in the memory segment size round
> + * up algorithm. The requested size is rounded up to PAGE_SIZE (4096), but
> + * if this roundup does not match HUGE_PAGE_SIZE (2Mb) boundary - the
> + * allocation fails.
> + *
> + * This bug is present in all RHEL6 versions, but not in RHEL7. It looks
> + * like this was fixed in mainstream kernel > v3.3 by the following patches:
> + *
> + * 091d0d5 (shm: fix null pointer deref when userspace specifies invalid hugepage size)
> + * af73e4d (hugetlbfs: fix mmap failure in unaligned size request)
> + * 42d7395 (mm: support more pagesizes for MAP_HUGETLB/SHM_HUGETLB)
> + * 40716e2 (hugetlbfs: fix alignment of huge page requests)
> + *
> + * AUTHOR
Authors
> + * Vladislav Dronov <vdronov@redhat.com>
> + * Li Wang <liwang@redhat.com>
> + *
> + */
> +
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <sys/types.h>
> +#include <sys/ipc.h>
> +#include <sys/shm.h>
> +#include <sys/mman.h>
> +#include <fcntl.h>
> +
> +#include "test.h"
> +#include "mem.h"
> +#include "hugetlb.h"
> +
> +char *TCID = "hugeshmat05";
> +int TST_TOTAL = 3;
> +
> +static long page_size;
> +static long hpage_size;
> +static long hugepages;
> +
> +#define N 4
> +
> +void setup(void)
> +{
> + tst_require_root();
> + check_hugepage();
> +
> + orig_hugepages = get_sys_tune("nr_hugepages");
> + page_size = getpagesize();
> + hpage_size = read_meminfo("Hugepagesize:") * 1024;
> +
> + hugepages = N + 1;
> + set_sys_tune("nr_hugepages", hugepages, 1);
> +
> + TEST_PAUSE;
> +}
> +
> +void cleanup(void)
> +{
> + set_sys_tune("nr_hugepages", orig_hugepages, 0);
> +}
> +
> +void shm_test(int size)
> +{
> + int shmid;
> + char *shmaddr;
> + key_t key = 5;
> +
> + shmid = shmget(key, size, SHM_R | SHM_W | IPC_CREAT | SHM_HUGETLB);
Why not just "shmid = shmget(IPC_PRIVATE, size, 0600 | IPC_CREAT |
SHM_HUGETLB);"? Do we need a key_t for the test?
> + if (shmid < 0)
> + tst_brkm(TBROK | TERRNO, cleanup, "shmget");
The message should be at least "shmget failed".
> +
> + shmaddr = shmat(shmid, 0, 0);
> + if (shmaddr == (char *)-1) {
> + shmctl(shmid, IPC_RMID, NULL);
> + tst_brkm(TFAIL | TERRNO, cleanup, "Bug: shared memory attach failure.");
> + }
> +
> + shmaddr[0] = 1;
> + tst_resm(TINFO, "allocated %d huge bytes", size);
> +
> + if (shmdt((const void *)shmaddr) != 0) {
> + shmctl(shmid, IPC_RMID, NULL);
> + tst_brkm(TFAIL | TERRNO, cleanup, "Detach failure.");
> + }
> +
> + shmctl(shmid, IPC_RMID, NULL);
> +}
> +
> +int main(int ac, char **av)
> +{
> + int lc, i;
> +
> + tst_parse_opts(ac, av, NULL, NULL);
> +
> + setup();
> +
> + for (lc = 0; TEST_LOOPING(lc); lc++) {
> + tst_count = 0;
> +
> + for (i = 0; i < TST_TOTAL; i++) {
> +
> + /* N*hpage_size - page_size FAIL */
> + shm_test(N * hpage_size - page_size);
> +
> + /* N*hpage_size - page_size - 1 SUCCESS*/
> + shm_test(N * hpage_size - page_size - 1);
> +
> + /* N*hpage_size SUCCESS */
> + shm_test(N * hpage_size);
> +
> + /* N*hpage_size + 1 FAIL */
> + shm_test(N * hpage_size + 1);
> +
> + tst_resm(TPASS, "No regression found.");
> + }
These two loops look very similar.
We can just call the test with -i 15 iterations in runtest, no need for
such a redundancy.
Otherwise it looks good.
Best regards,
Alexey
> + }
> +
> + cleanup();
> + tst_exit();
> +}
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