strace/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

65 lines
2.2 KiB
C

/*
* Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org>
* Copyright (c) 2015-2017 The strace developers.
* 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 "defs.h"
#ifdef HAVE_LINUX_MEMFD_H
# include <linux/memfd.h>
#endif
#include "xlat/memfd_create_flags.h"
#ifndef MFD_HUGE_SHIFT
# define MFD_HUGE_SHIFT 26
#endif
#ifndef MFD_HUGE_MASK
# define MFD_HUGE_MASK 0x3f
#endif
SYS_FUNC(memfd_create)
{
printpathn(tcp, tcp->u_arg[0], 255 - (sizeof("memfd:") - 1));
tprints(", ");
unsigned int flags = tcp->u_arg[1];
const unsigned int mask = MFD_HUGE_MASK << MFD_HUGE_SHIFT;
const unsigned int hugetlb_value = flags & mask;
flags &= ~mask;
if (flags || !hugetlb_value)
printflags(memfd_create_flags, flags, "MFD_???");
if (hugetlb_value)
tprintf("%s%u<<MFD_HUGE_SHIFT",
flags ? "|" : "",
hugetlb_value >> MFD_HUGE_SHIFT);
return RVAL_DECODED | RVAL_FD;
}