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) 2014-2018 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                 enum user_desc_print_filter filter)
  47 {
  48         struct user_desc desc;
  49         unsigned *entry_number = get_tcb_priv_data(tcp);
  50
  51         switch (filter) {
  52         case USER_DESC_ENTERING:
  53                 if (umove_or_printaddr(tcp, addr, &desc.entry_number))
  54                         return;
  55
  56                 break;
  57
  58         case USER_DESC_EXITING:
  59                 if (!addr || !verbose(tcp))
  60                         return;
  61                 if (syserror(tcp) || umove(tcp, addr, &desc)) {
  62                         if (entry_number)
  63                                 tprints(", ...}");
  64
  65                         return;
  66                 }
  67
  68                 break;
  69
  70         case USER_DESC_BOTH:
  71                 if (umove_or_printaddr(tcp, addr, &desc))
  72                         return;
  73
  74                 break;
  75         }
  76
  77         if (filter & USER_DESC_ENTERING) {
  78                 PRINT_FIELD_ID("{", desc, entry_number);
  79
  80                 /*
  81                  * If we don't print the whole structure now, let's save it for
  82                  * later.
  83                  */
  84                 if (filter == USER_DESC_ENTERING) {
  85                         entry_number = xmalloc(sizeof(*entry_number));
  86
  87                         *entry_number = desc.entry_number;
  88                         set_tcb_priv_data(tcp, entry_number, free);
  89                 }
  90         }
  91
  92         if (filter & USER_DESC_EXITING) {
  93                 /*
  94                  * It should be the same in case of get_thread_area, but we can
  95                  * never be sure...
  96                  */
  97                 if (filter == USER_DESC_EXITING) {
  98                         if (entry_number) {
  99                                 if (*entry_number != desc.entry_number) {
 100                                         if ((int) desc.entry_number == -1)
 101                                                 tprints(" => -1");
 102                                         else
 103                                                 tprintf(" => %u",
 104                                                         desc.entry_number);
 105                                 }
 106                         } else {
 107                                 /*
 108                                  * This is really strange. If we are here, it
 109                                  * means that we failed on entering but somehow
 110                                  * succeeded on exiting.
 111                                  */
 112                                 PRINT_FIELD_ID(" => {", desc, entry_number);
 113                         }
 114                 }
 115
 116                 PRINT_FIELD_0X(", ", desc, base_addr);
 117                 PRINT_FIELD_0X(", ", desc, limit);
 118                 PRINT_FIELD_U_CAST(", ", desc, seg_32bit, unsigned int);
 119                 PRINT_FIELD_U_CAST(", ", desc, contents, unsigned int);
 120                 PRINT_FIELD_U_CAST(", ", desc, read_exec_only, unsigned int);
 121                 PRINT_FIELD_U_CAST(", ", desc, limit_in_pages, unsigned int);
 122                 PRINT_FIELD_U_CAST(", ", desc, seg_not_present, unsigned int);
 123                 PRINT_FIELD_U_CAST(", ", desc, useable, unsigned int);
 124
 125 # ifdef HAVE_STRUCT_USER_DESC_LM
 126                 /* lm is totally ignored for 32-bit processes */
 127                 if (current_klongsize == 8)
 128                         PRINT_FIELD_U_CAST(", ", desc, lm, unsigned int);
 129 # endif /* HAVE_STRUCT_USER_DESC_LM */
 130
 131                 tprints("}");
 132         }
 133 }
 134
 135 SYS_FUNC(modify_ldt)
 136 {
 137         if (entering(tcp)) {
 138                 tprintf("%d, ", (int) tcp->u_arg[0]);
 139                 if (tcp->u_arg[2] != sizeof(struct user_desc))
 140                         printaddr(tcp->u_arg[1]);
 141                 else
 142                         print_user_desc(tcp, tcp->u_arg[1], USER_DESC_BOTH);
 143                 tprintf(", %" PRI_klu, tcp->u_arg[2]);
 144
 145                 return 0;
 146         }
 147
 148         /*
 149          * For some reason ("tht ABI for sys_modify_ldt() expects
 150          * 'int'"), modify_ldt clips higher bits on x86_64.
 151          */
 152
 153         if (syserror(tcp) || (kernel_ulong_t) tcp->u_rval < 0xfffff000)
 154                 return 0;
 155
 156         tcp->u_error = -(unsigned int) tcp->u_rval;
 157
 158         return 0;
 159 }
 160
 161 SYS_FUNC(set_thread_area)
 162 {
 163         if (entering(tcp)) {
 164                 print_user_desc(tcp, tcp->u_arg[0], USER_DESC_BOTH);
 165         } else {
 166                 struct user_desc desc;
 167
 168                 if (!verbose(tcp) || syserror(tcp) ||
 169                     umove(tcp, tcp->u_arg[0], &desc) < 0) {
 170                         /* returned entry_number is not available */
 171                 } else {
 172                         static char outstr[32];
 173
 174                         xsprintf(outstr, "entry_number=%u", desc.entry_number);
 175                         tcp->auxstr = outstr;
 176                         return RVAL_STR;
 177                 }
 178         }
 179         return 0;
 180 }
 181
 182 SYS_FUNC(get_thread_area)
 183 {
 184         print_user_desc(tcp, tcp->u_arg[0],
 185                         entering(tcp) ? USER_DESC_ENTERING : USER_DESC_EXITING);
 186         return 0;
 187 }
 188
 189 #endif /* HAVE_STRUCT_USER_DESC */
 190
 191 #if defined(M68K) || defined(MIPS)
 192 SYS_FUNC(set_thread_area)
 193 {
 194         printaddr(tcp->u_arg[0]);
 195
 196         return RVAL_DECODED;
 197
 198 }
 199 #endif
 200
 201 #if defined(M68K)
 202 SYS_FUNC(get_thread_area)
 203 {
 204         return RVAL_DECODED | RVAL_HEX;
 205 }
 206 #endif