granicus.if.org Git - strace/blob - ldt.c

   1 /*
   2  * Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
   3  * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
   4  * Copyright (c) 1993-1996 Rick Sladkey <jrs@world.std.com>
   5  * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
   6  * Copyright (c) 2002-2004 Roland McGrath <roland@redhat.com>
   7  * Copyright (c) 2010 Andreas Schwab <schwab@linux-m68k.org>
   8  * Copyright (c) 2014-2015 Dmitry V. Levin <ldv@altlinux.org>
   9  * Copyright (c) 2014-2017 The strace developers.
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. The name of the author may not be used to endorse or promote products
  21  *    derived from this software without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include "defs.h"
  36
  37 #ifdef HAVE_STRUCT_USER_DESC
  38
  39 # include <asm/ldt.h>
  40
  41 # include "print_fields.h"
  42 # include "xstring.h"
  43
  44 void
  45 print_user_desc(struct tcb *const tcp, const kernel_ulong_t addr)
  46 {
  47         struct user_desc desc;
  48
  49         if (umove_or_printaddr(tcp, addr, &desc))
  50                 return;
  51
  52         PRINT_FIELD_ID("{",  desc, entry_number);
  53         PRINT_FIELD_0X(", ", desc, base_addr);
  54         PRINT_FIELD_0X(", ", desc, limit);
  55         PRINT_FIELD_U_CAST(", ", desc, seg_32bit, unsigned int);
  56         PRINT_FIELD_U_CAST(", ", desc, contents, unsigned int);
  57         PRINT_FIELD_U_CAST(", ", desc, read_exec_only, unsigned int);
  58         PRINT_FIELD_U_CAST(", ", desc, limit_in_pages, unsigned int);
  59         PRINT_FIELD_U_CAST(", ", desc, seg_not_present, unsigned int);
  60         PRINT_FIELD_U_CAST(", ", desc, useable, unsigned int);
  61
  62 # ifdef HAVE_STRUCT_USER_DESC_LM
  63         /* lm is totally ignored for 32-bit processes */
  64         if (current_klongsize == 8)
  65                 PRINT_FIELD_U_CAST(", ", desc, lm, unsigned int);
  66 # endif /* HAVE_STRUCT_USER_DESC_LM */
  67
  68         tprints("}");
  69 }
  70
  71 SYS_FUNC(modify_ldt)
  72 {
  73         if (entering(tcp)) {
  74                 tprintf("%d, ", (int) tcp->u_arg[0]);
  75                 if (tcp->u_arg[2] != sizeof(struct user_desc))
  76                         printaddr(tcp->u_arg[1]);
  77                 else
  78                         print_user_desc(tcp, tcp->u_arg[1]);
  79                 tprintf(", %" PRI_klu, tcp->u_arg[2]);
  80
  81                 return 0;
  82         }
  83
  84         /*
  85          * For some reason ("tht ABI for sys_modify_ldt() expects
  86          * 'int'"), modify_ldt clips higher bits on x86_64.
  87          */
  88
  89         if (syserror(tcp) || (kernel_ulong_t) tcp->u_rval < 0xfffff000)
  90                 return 0;
  91
  92         tcp->u_error = -(unsigned int) tcp->u_rval;
  93
  94         return RVAL_PRINT_ERR_VAL;
  95 }
  96
  97 SYS_FUNC(set_thread_area)
  98 {
  99         if (entering(tcp)) {
 100                 print_user_desc(tcp, tcp->u_arg[0]);
 101         } else {
 102                 struct user_desc desc;
 103
 104                 if (!verbose(tcp) || syserror(tcp) ||
 105                     umove(tcp, tcp->u_arg[0], &desc) < 0) {
 106                         /* returned entry_number is not available */
 107                 } else {
 108                         static char outstr[32];
 109
 110                         xsprintf(outstr, "entry_number=%u", desc.entry_number);
 111                         tcp->auxstr = outstr;
 112                         return RVAL_STR;
 113                 }
 114         }
 115         return 0;
 116 }
 117
 118 SYS_FUNC(get_thread_area)
 119 {
 120         if (exiting(tcp))
 121                 print_user_desc(tcp, tcp->u_arg[0]);
 122         return 0;
 123 }
 124
 125 #endif /* HAVE_STRUCT_USER_DESC */
 126
 127 #if defined(M68K) || defined(MIPS)
 128 SYS_FUNC(set_thread_area)
 129 {
 130         printaddr(tcp->u_arg[0]);
 131
 132         return RVAL_DECODED;
 133
 134 }
 135 #endif
 136
 137 #if defined(M68K)
 138 SYS_FUNC(get_thread_area)
 139 {
 140         return RVAL_DECODED | RVAL_HEX;
 141 }
 142 #endif