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1 /*
2  * Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org>
3  * Copyright (c) 2015-2017 The strace developers.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "defs.h"
30 
31 #ifdef HAVE_LINUX_MEMFD_H
32 # include <linux/memfd.h>
33 #endif
34 
35 #include "xlat/memfd_create_flags.h"
36 
37 #ifndef MFD_HUGE_SHIFT
38 # define MFD_HUGE_SHIFT 26
39 #endif
40 
41 #ifndef MFD_HUGE_MASK
42 # define MFD_HUGE_MASK 0x3f
43 #endif
44 
SYS_FUNC(memfd_create)45 SYS_FUNC(memfd_create)
46 {
47 	printpathn(tcp, tcp->u_arg[0], 255 - (sizeof("memfd:") - 1));
48 	tprints(", ");
49 
50 	unsigned int flags = tcp->u_arg[1];
51 	const unsigned int mask = MFD_HUGE_MASK << MFD_HUGE_SHIFT;
52 	const unsigned int hugetlb_value = flags & mask;
53 	flags &= ~mask;
54 
55 	if (flags || !hugetlb_value)
56 		printflags(memfd_create_flags, flags, "MFD_???");
57 
58 	if (hugetlb_value)
59 		tprintf("%s%u<<MFD_HUGE_SHIFT",
60 			flags ? "|" : "",
61 			hugetlb_value >> MFD_HUGE_SHIFT);
62 
63 	return RVAL_DECODED | RVAL_FD;
64 }
65