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

   1 #include "defs.h"
   2
   3 #include <sys/wait.h>
   4
   5 #ifndef __WNOTHREAD
   6 # define __WNOTHREAD    0x20000000
   7 #endif
   8 #ifndef __WALL
   9 # define __WALL         0x40000000
  10 #endif
  11 #ifndef __WCLONE
  12 # define __WCLONE       0x80000000
  13 #endif
  14
  15 #include "xlat/wait4_options.h"
  16
  17 #if !defined WCOREFLAG && defined WCOREFLG
  18 # define WCOREFLAG WCOREFLG
  19 #endif
  20 #ifndef WCOREFLAG
  21 # define WCOREFLAG 0x80
  22 #endif
  23 #ifndef WCOREDUMP
  24 # define WCOREDUMP(status)  ((status) & 0200)
  25 #endif
  26 #ifndef W_STOPCODE
  27 # define W_STOPCODE(sig)  ((sig) << 8 | 0x7f)
  28 #endif
  29 #ifndef W_EXITCODE
  30 # define W_EXITCODE(ret, sig)  ((ret) << 8 | (sig))
  31 #endif
  32
  33 static int
  34 printstatus(int status)
  35 {
  36         int exited = 0;
  37
  38         /*
  39          * Here is a tricky presentation problem.  This solution
  40          * is still not entirely satisfactory but since there
  41          * are no wait status constructors it will have to do.
  42          */
  43         if (WIFSTOPPED(status)) {
  44                 tprintf("[{WIFSTOPPED(s) && WSTOPSIG(s) == %s}",
  45                         signame(WSTOPSIG(status)));
  46                 status &= ~W_STOPCODE(WSTOPSIG(status));
  47         }
  48         else if (WIFSIGNALED(status)) {
  49                 tprintf("[{WIFSIGNALED(s) && WTERMSIG(s) == %s%s}",
  50                         signame(WTERMSIG(status)),
  51                         WCOREDUMP(status) ? " && WCOREDUMP(s)" : "");
  52                 status &= ~(W_EXITCODE(0, WTERMSIG(status)) | WCOREFLAG);
  53         }
  54         else if (WIFEXITED(status)) {
  55                 tprintf("[{WIFEXITED(s) && WEXITSTATUS(s) == %d}",
  56                         WEXITSTATUS(status));
  57                 exited = 1;
  58                 status &= ~W_EXITCODE(WEXITSTATUS(status), 0);
  59         }
  60         else {
  61                 tprintf("[%#x]", status);
  62                 return 0;
  63         }
  64
  65         if (status == 0)
  66                 tprints("]");
  67         else
  68                 tprintf(" | %#x]", status);
  69
  70         return exited;
  71 }
  72
  73 static int
  74 printwaitn(struct tcb *tcp, int n, int bitness)
  75 {
  76         int status;
  77
  78         if (entering(tcp)) {
  79                 /* On Linux, kernel-side pid_t is typedef'ed to int
  80                  * on all arches. Also, glibc-2.8 truncates wait3 and wait4
  81                  * pid argument to int on 64bit arches, producing,
  82                  * for example, wait4(4294967295, ...) instead of -1
  83                  * in strace. We have to use int here, not long.
  84                  */
  85                 int pid = tcp->u_arg[0];
  86                 tprintf("%d, ", pid);
  87         } else {
  88                 /* status */
  89                 if (!tcp->u_arg[1])
  90                         tprints("NULL");
  91                 else if (syserror(tcp) || tcp->u_rval == 0)
  92                         tprintf("%#lx", tcp->u_arg[1]);
  93                 else if (umove(tcp, tcp->u_arg[1], &status) < 0)
  94                         tprints("[?]");
  95                 else
  96                         printstatus(status);
  97                 /* options */
  98                 tprints(", ");
  99                 printflags(wait4_options, tcp->u_arg[2], "W???");
 100                 if (n == 4) {
 101                         tprints(", ");
 102                         /* usage */
 103                         if (!tcp->u_arg[3])
 104                                 tprints("NULL");
 105                         else if (tcp->u_rval > 0) {
 106 #ifdef ALPHA
 107                                 if (bitness)
 108                                         printrusage32(tcp, tcp->u_arg[3]);
 109                                 else
 110 #endif
 111                                         printrusage(tcp, tcp->u_arg[3]);
 112                         }
 113                         else
 114                                 tprintf("%#lx", tcp->u_arg[3]);
 115                 }
 116         }
 117         return 0;
 118 }
 119
 120 int
 121 sys_waitpid(struct tcb *tcp)
 122 {
 123         return printwaitn(tcp, 3, 0);
 124 }
 125
 126 int
 127 sys_wait4(struct tcb *tcp)
 128 {
 129         return printwaitn(tcp, 4, 0);
 130 }
 131
 132 #ifdef ALPHA
 133 int
 134 sys_osf_wait4(struct tcb *tcp)
 135 {
 136         return printwaitn(tcp, 4, 1);
 137 }
 138 #endif
 139
 140 #include "xlat/waitid_types.h"
 141
 142 int
 143 sys_waitid(struct tcb *tcp)
 144 {
 145         if (entering(tcp)) {
 146                 printxval(waitid_types, tcp->u_arg[0], "P_???");
 147                 tprintf(", %ld, ", tcp->u_arg[1]);
 148         }
 149         else {
 150                 /* siginfo */
 151                 printsiginfo_at(tcp, tcp->u_arg[2]);
 152                 /* options */
 153                 tprints(", ");
 154                 printflags(wait4_options, tcp->u_arg[3], "W???");
 155                 if (tcp->s_ent->nargs > 4) {
 156                         /* usage */
 157                         tprints(", ");
 158                         if (!tcp->u_arg[4])
 159                                 tprints("NULL");
 160                         else if (tcp->u_error)
 161                                 tprintf("%#lx", tcp->u_arg[4]);
 162                         else
 163                                 printrusage(tcp, tcp->u_arg[4]);
 164                 }
 165         }
 166         return 0;
 167 }