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

   1 /*
   2  * Copyright (c) 1993 Ulrich Pegelow <pegelow@moorea.uni-muenster.de>
   3  * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
   4  * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
   5  * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
   6  * Copyright (c) 2003-2006 Roland McGrath <roland@redhat.com>
   7  * Copyright (c) 2006-2015 Dmitry V. Levin <ldv@altlinux.org>
   8  * Copyright (c) 2015-2018 The strace developers.
   9  * All rights reserved.
  10  *
  11  * SPDX-License-Identifier: LGPL-2.1-or-later
  12  */
  13
  14 #include "defs.h"
  15
  16 #ifdef HAVE_SYS_SHM_H
  17 # include <sys/shm.h>
  18 #elif defined HAVE_LINUX_SHM_H
  19 # include <linux/shm.h>
  20 #endif
  21
  22 #ifndef SHM_HUGE_SHIFT
  23 # define SHM_HUGE_SHIFT 26
  24 #endif
  25
  26 #ifndef SHM_HUGE_MASK
  27 # define SHM_HUGE_MASK 0x3f
  28 #endif
  29
  30 #include "xlat/shm_resource_flags.h"
  31 #include "xlat/shm_flags.h"
  32
  33 SYS_FUNC(shmget)
  34 {
  35         printxval(ipc_private, (unsigned int) tcp->u_arg[0], NULL);
  36         tprintf(", %" PRI_klu ", ", tcp->u_arg[1]);
  37
  38         unsigned int flags = tcp->u_arg[2] & ~0777;
  39         const unsigned int mask = SHM_HUGE_MASK << SHM_HUGE_SHIFT;
  40         const unsigned int hugetlb_value = flags & mask;
  41
  42         flags &= ~mask;
  43         if (flags || !hugetlb_value)
  44                 printflags(shm_resource_flags, flags, NULL);
  45
  46         if (hugetlb_value) {
  47                 tprintf("%s%u<<",
  48                         flags ? "|" : "",
  49                         hugetlb_value >> SHM_HUGE_SHIFT);
  50                 print_xlat_u(SHM_HUGE_SHIFT);
  51         }
  52
  53         if (flags || hugetlb_value)
  54                 tprints("|");
  55         print_numeric_umode_t(tcp->u_arg[2] & 0777);
  56
  57         return RVAL_DECODED;
  58 }
  59
  60 SYS_FUNC(shmat)
  61 {
  62         if (entering(tcp)) {
  63                 tprintf("%d, ", (int) tcp->u_arg[0]);
  64                 if (indirect_ipccall(tcp)) {
  65                         printaddr(tcp->u_arg[3]);
  66                         tprints(", ");
  67                         printflags(shm_flags, tcp->u_arg[1], "SHM_???");
  68                 } else {
  69                         printaddr(tcp->u_arg[1]);
  70                         tprints(", ");
  71                         printflags(shm_flags, tcp->u_arg[2], "SHM_???");
  72                 }
  73                 return 0;
  74         } else {
  75                 if (syserror(tcp))
  76                         return 0;
  77                 if (indirect_ipccall(tcp)) {
  78                         union {
  79                                 uint64_t r64;
  80                                 uint32_t r32;
  81                         } u;
  82                         if (umoven(tcp, tcp->u_arg[2], current_wordsize, &u) < 0)
  83                                 return RVAL_NONE;
  84                         tcp->u_rval = (sizeof(u.r32) == current_wordsize)
  85                                       ? u.r32 : u.r64;
  86                 }
  87                 return RVAL_HEX;
  88         }
  89 }
  90
  91 SYS_FUNC(shmdt)
  92 {
  93         printaddr(tcp->u_arg[indirect_ipccall(tcp) ? 3 : 0]);
  94         return RVAL_DECODED;
  95 }