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      1 /*
      2  * Copyright (c) 2015 Dmitry V. Levin <ldv (at) altlinux.org>
      3  * Copyright (c) 2014-2018 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 #include "xstring.h"
     31 
     32 enum {
     33 	IOPRIO_WHO_PROCESS = 1,
     34 	IOPRIO_WHO_PGRP,
     35 	IOPRIO_WHO_USER
     36 };
     37 
     38 #include "xlat/ioprio_who.h"
     39 
     40 enum {
     41 	IOPRIO_CLASS_NONE,
     42 	IOPRIO_CLASS_RT,
     43 	IOPRIO_CLASS_BE,
     44 	IOPRIO_CLASS_IDLE
     45 };
     46 
     47 #include "xlat/ioprio_class.h"
     48 
     49 #define IOPRIO_CLASS_SHIFT	(13)
     50 #define IOPRIO_PRIO_MASK	((1ul << IOPRIO_CLASS_SHIFT) - 1)
     51 
     52 #define IOPRIO_PRIO_CLASS(mask)	((mask) >> IOPRIO_CLASS_SHIFT)
     53 #define IOPRIO_PRIO_DATA(mask)	((mask) & IOPRIO_PRIO_MASK)
     54 
     55 static const char *
     56 sprint_ioprio(unsigned int ioprio)
     57 {
     58 	static char outstr[256];
     59 	const char *str;
     60 	unsigned int class, data;
     61 
     62 	class = IOPRIO_PRIO_CLASS(ioprio);
     63 	data = IOPRIO_PRIO_DATA(ioprio);
     64 	str = xlookup(ioprio_class, class);
     65 	if (str)
     66 		xsprintf(outstr, "IOPRIO_PRIO_VALUE(%s, %d)", str, data);
     67 	else
     68 		xsprintf(outstr, "IOPRIO_PRIO_VALUE(%#x /* %s */, %d)",
     69 			 class, "IOPRIO_CLASS_???", data);
     70 
     71 	return outstr;
     72 }
     73 
     74 SYS_FUNC(ioprio_get)
     75 {
     76 	if (entering(tcp)) {
     77 		/* int which */
     78 		printxval(ioprio_who, tcp->u_arg[0], "IOPRIO_WHO_???");
     79 		/* int who */
     80 		tprintf(", %d", (int) tcp->u_arg[1]);
     81 		return 0;
     82 	} else {
     83 		if (syserror(tcp))
     84 			return 0;
     85 
     86 		tcp->auxstr = sprint_ioprio(tcp->u_rval);
     87 		return RVAL_STR;
     88 	}
     89 }
     90 
     91 SYS_FUNC(ioprio_set)
     92 {
     93 	/* int which */
     94 	printxval(ioprio_who, tcp->u_arg[0], "IOPRIO_WHO_???");
     95 	/* int who */
     96 	tprintf(", %d, ", (int) tcp->u_arg[1]);
     97 	/* int ioprio */
     98 	tprints(sprint_ioprio(tcp->u_arg[2]));
     99 
    100 	return RVAL_DECODED;
    101 }
    102