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

   1 /*
   2  * Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org>
   3  * Copyright (c) 2015-2017 The strace developers.
   4  * All rights reserved.
   5  *
   6  * SPDX-License-Identifier: LGPL-2.1-or-later
   7  */
   8
   9 #include "defs.h"
  10 #include "print_fields.h"
  11 #include "xlat/kcmp_types.h"
  12
  13 struct strace_kcmp_epoll_slot {
  14         uint32_t efd;
  15         uint32_t tfd;
  16         uint32_t toff;
  17 };
  18
  19 static void
  20 printpidfd(struct tcb *tcp, pid_t pid, int fd)
  21 {
  22         /*
  23          * XXX We want to use printfd here, but we should figure out which
  24          *     process in strace's PID NS is referred to first.
  25          */
  26         tprintf("%d", fd);
  27 }
  28
  29 #define PRINT_FIELD_PIDFD(prefix_, where_, field_, tcp_, pid_)          \
  30         do {                                                            \
  31                 STRACE_PRINTF("%s%s=", (prefix_), #field_);             \
  32                 printpidfd((tcp_), (pid_), (where_).field_);            \
  33         } while (0)
  34
  35 SYS_FUNC(kcmp)
  36 {
  37         pid_t pid1 = tcp->u_arg[0];
  38         pid_t pid2 = tcp->u_arg[1];
  39         int type = tcp->u_arg[2];
  40         kernel_ulong_t idx1 = tcp->u_arg[3];
  41         kernel_ulong_t idx2 = tcp->u_arg[4];
  42
  43         tprintf("%d, %d, ", pid1, pid2);
  44         printxval(kcmp_types, type, "KCMP_???");
  45
  46         switch (type) {
  47                 case KCMP_FILE:
  48                         tprints(", ");
  49                         printpidfd(tcp, pid1, idx1);
  50                         tprints(", ");
  51                         printpidfd(tcp, pid1, idx2);
  52
  53                         break;
  54
  55                 case KCMP_EPOLL_TFD: {
  56                         struct strace_kcmp_epoll_slot slot;
  57
  58                         tprints(", ");
  59                         printpidfd(tcp, pid1, idx1);
  60                         tprints(", ");
  61
  62                         if (umove_or_printaddr(tcp, idx2, &slot))
  63                                 break;
  64
  65                         PRINT_FIELD_PIDFD("{",  slot, efd, tcp, pid2);
  66                         PRINT_FIELD_PIDFD(", ", slot, tfd, tcp, pid2);
  67                         PRINT_FIELD_U(", ", slot, toff);
  68                         tprints("}");
  69
  70                         break;
  71                 }
  72
  73                 case KCMP_FILES:
  74                 case KCMP_FS:
  75                 case KCMP_IO:
  76                 case KCMP_SIGHAND:
  77                 case KCMP_SYSVSEM:
  78                 case KCMP_VM:
  79                         break;
  80                 default:
  81                         tprintf(", %#" PRI_klx ", %#" PRI_klx, idx1, idx2);
  82         }
  83
  84         return RVAL_DECODED;
  85 }