granicus.if.org Git - strace/blob - wait.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) 2004 Ulrich Drepper <drepper@redhat.com>
   8  * Copyright (c) 2009-2013 Denys Vlasenko <dvlasenk@redhat.com>
   9  * Copyright (c) 2014-2015 Dmitry V. Levin <ldv@altlinux.org>
  10  * Copyright (c) 2014-2018 The strace developers.
  11  * All rights reserved.
  12  *
  13  * SPDX-License-Identifier: LGPL-2.1-or-later
  14  */
  15
  16 #include "defs.h"
  17 #include "ptrace.h"
  18
  19 #include "wait.h"
  20
  21 #include "xlat/wait4_options.h"
  22 #include "xlat/ptrace_events.h"
  23
  24 static int
  25 printstatus(int status)
  26 {
  27         int exited = 0;
  28
  29         /*
  30          * Here is a tricky presentation problem.  This solution
  31          * is still not entirely satisfactory but since there
  32          * are no wait status constructors it will have to do.
  33          */
  34         if (WIFSTOPPED(status)) {
  35                 int sig = WSTOPSIG(status);
  36                 tprintf("[{WIFSTOPPED(s) && WSTOPSIG(s) == %s%s}",
  37                         sprintsigname(sig & 0x7f),
  38                         sig & 0x80 ? " | 0x80" : "");
  39                 status &= ~W_STOPCODE(sig);
  40         } else if (WIFSIGNALED(status)) {
  41                 tprintf("[{WIFSIGNALED(s) && WTERMSIG(s) == %s%s}",
  42                         sprintsigname(WTERMSIG(status)),
  43                         WCOREDUMP(status) ? " && WCOREDUMP(s)" : "");
  44                 status &= ~(W_EXITCODE(0, WTERMSIG(status)) | WCOREFLAG);
  45         } else if (WIFEXITED(status)) {
  46                 tprintf("[{WIFEXITED(s) && WEXITSTATUS(s) == %d}",
  47                         WEXITSTATUS(status));
  48                 exited = 1;
  49                 status &= ~W_EXITCODE(WEXITSTATUS(status), 0);
  50         }
  51 #ifdef WIFCONTINUED
  52         else if (WIFCONTINUED(status)) {
  53                 tprints("[{WIFCONTINUED(s)}");
  54                 status &= ~W_CONTINUED;
  55         }
  56 #endif
  57         else {
  58                 tprintf("[%#x]", status);
  59                 return 0;
  60         }
  61
  62         if (status) {
  63                 unsigned int event = (unsigned int) status >> 16;
  64                 if (event) {
  65                         tprints(" | ");
  66                         printxval(ptrace_events, event, "PTRACE_EVENT_???");
  67                         tprints(" << 16");
  68                         status &= 0xffff;
  69                 }
  70                 if (status)
  71                         tprintf(" | %#x", status);
  72         }
  73         tprints("]");
  74
  75         return exited;
  76 }
  77
  78 static int
  79 printwaitn(struct tcb *const tcp,
  80            void (*const print_rusage)(struct tcb *, kernel_ulong_t))
  81 {
  82         if (entering(tcp)) {
  83                 /* On Linux, kernel-side pid_t is typedef'ed to int
  84                  * on all arches. Also, glibc-2.8 truncates wait3 and wait4
  85                  * pid argument to int on 64bit arches, producing,
  86                  * for example, wait4(4294967295, ...) instead of -1
  87                  * in strace. We have to use int here, not long.
  88                  */
  89                 int pid = tcp->u_arg[0];
  90                 tprintf("%d, ", pid);
  91         } else {
  92                 int status;
  93
  94                 /* status */
  95                 if (tcp->u_rval == 0)
  96                         printaddr(tcp->u_arg[1]);
  97                 else if (!umove_or_printaddr(tcp, tcp->u_arg[1], &status))
  98                         printstatus(status);
  99                 /* options */
 100                 tprints(", ");
 101                 printflags(wait4_options, tcp->u_arg[2], "W???");
 102                 if (print_rusage) {
 103                         /* usage */
 104                         tprints(", ");
 105                         if (tcp->u_rval > 0)
 106                                 print_rusage(tcp, tcp->u_arg[3]);
 107                         else
 108                                 printaddr(tcp->u_arg[3]);
 109                 }
 110         }
 111         return 0;
 112 }
 113
 114 SYS_FUNC(waitpid)
 115 {
 116         return printwaitn(tcp, NULL);
 117 }
 118
 119 SYS_FUNC(wait4)
 120 {
 121         return printwaitn(tcp, printrusage);
 122 }
 123
 124 #ifdef ALPHA
 125 SYS_FUNC(osf_wait4)
 126 {
 127         return printwaitn(tcp, printrusage32);
 128 }
 129 #endif
 130
 131 #include "xlat/waitid_types.h"
 132
 133 SYS_FUNC(waitid)
 134 {
 135         if (entering(tcp)) {
 136                 printxval(waitid_types, tcp->u_arg[0], "P_???");
 137                 int pid = tcp->u_arg[1];
 138                 tprintf(", %d, ", pid);
 139         } else {
 140                 /* siginfo */
 141                 printsiginfo_at(tcp, tcp->u_arg[2]);
 142                 /* options */
 143                 tprints(", ");
 144                 printflags(wait4_options, tcp->u_arg[3], "W???");
 145                 /* usage */
 146                 tprints(", ");
 147                 printrusage(tcp, tcp->u_arg[4]);
 148         }
 149         return 0;
 150 }