strace/tests/memfd_create.c
Dmitry V. Levin 1898689dbf memfd_create: decode hugetlb page size
Decode alternative hugetlb page sizes introduced by kernel commit
v4.14-rc1~126^2~17.

* configure.ac (AC_CHECK_HEADERS): Add linux/memfd.h.
* memfd_create.c [HAVE_LINUX_MEMFD_H]: Include it.
[!MFD_HUGE_SHIFT] (MFD_HUGE_SHIFT): New macro.
[!MFD_HUGE_MASK] (MFD_HUGE_MASK): Likewise.
(SYS_FUNC(memfd_create)): Print hugetlb page size.
* tests/memfd_create.c: Check it.
2017-11-18 00:19:31 +00:00

103 lines
3.2 KiB
C

/*
* Check decoding of memfd_create syscall.
*
* Copyright (c) 2015-2017 Dmitry V. Levin <ldv@altlinux.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "tests.h"
#include <asm/unistd.h>
#include "scno.h"
#ifdef __NR_memfd_create
# include <stdio.h>
# include <stdint.h>
# include <unistd.h>
# ifdef HAVE_LINUX_MEMFD_H
# include <linux/memfd.h>
# endif
# ifndef MFD_HUGE_SHIFT
# define MFD_HUGE_SHIFT 26
# endif
# ifndef MFD_HUGE_MASK
# define MFD_HUGE_MASK 0x3f
# endif
static const char *errstr;
static long
k_memfd_create(const kernel_ulong_t name, const kernel_ulong_t flags)
{
const long rc = syscall(__NR_memfd_create, name, flags);
errstr = sprintrc(rc);
return rc;
}
int
main(void)
{
const size_t size = 255 - (sizeof("memfd:") - 1) + 1;
char *pattern = tail_alloc(size);
fill_memory_ex(pattern, size, '0', 10);
k_memfd_create((uintptr_t) pattern, 0);
printf("memfd_create(\"%.*s\"..., 0) = %s\n",
(int) size - 1, pattern, errstr);
kernel_ulong_t flags = (kernel_ulong_t) 0xfacefeed00000007ULL;
k_memfd_create((uintptr_t) pattern, flags);
printf("memfd_create(\"%.*s\"..., %s) = %s\n",
(int) size - 1, pattern,
"MFD_CLOEXEC|MFD_ALLOW_SEALING|MFD_HUGETLB",
errstr);
pattern[size - 1] = '\0';
flags = 30 << MFD_HUGE_SHIFT;
k_memfd_create((uintptr_t) pattern, flags);
printf("memfd_create(\"%s\", 30<<MFD_HUGE_SHIFT) = %s\n",
pattern, errstr);
pattern += size - 1;
flags = (kernel_ulong_t) -1ULL;
k_memfd_create(0, flags);
flags = -1U & ~(7 | (MFD_HUGE_MASK << MFD_HUGE_SHIFT));
printf("memfd_create(NULL, MFD_CLOEXEC|MFD_ALLOW_SEALING|MFD_HUGETLB"
"|%#x|%u<<MFD_HUGE_SHIFT) = %s\n",
(unsigned int) flags, MFD_HUGE_MASK, errstr);
puts("+++ exited with 0 +++");
return 0;
}
#else
SKIP_MAIN_UNDEFINED("__NR_memfd_create")
#endif