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      1 /*
      2  * Copyright (c) 2015 Dmitry V. Levin <ldv (at) 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 
     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