usttrace

   1 #!/bin/bash
   2
   3 # usttrace  by Pierre-Marc Fournier 2009
   4 # Distributed under the GPLv2.
   5
   6 function error() {
   7         echo "$0: error: $1" 2>/dev/stderr
   8 }
   9
  10 USTTRACE_DIR="$(dirname $0)"
  11 if [ -x "${USTTRACE_DIR}/ustd/ustd" ] ; then
  12     # Use the not installed libraries instead
  13     USTD="${USTTRACE_DIR}/ustd/ustd"
  14     LIBINTERFORK_PATH="${USTTRACE_DIR}/libinterfork/.libs/libinterfork.so"
  15     LIBMALLOCWRAP_PATH="${USTTRACE_DIR}/libmallocwrap/.libs/libmallocwrap.so"
  16     LIBUST_PATH="${USTTRACE_DIR}/libust/.libs/libust.so"
  17 else
  18     # Use the libraries that the dynamic link finds
  19     USTD="ustd"
  20     if [ ! -x "$(which ustd 2>/dev/null)" ]; then
  21         error "cannot find an executable ustd; make sure its location is in the PATH"
  22         exit 1
  23     fi
  24     LIBINTERFORK_PATH="libinterfork.so"
  25     LIBMALLOCWRAP_PATH="libmallocwrap.so"
  26     LIBUST_PATH="libust.so"
  27 fi
  28
  29 BASE_TRACE_DIR="${HOME}/.usttraces"
  30
  31 function usage () {
  32         echo "usage:  $0 OPTIONS COMMAND" 2>/dev/stderr
  33         echo "" 2>/dev/stderr
  34         echo "Options:" 2>/dev/stderr
  35         echo "    -l    Runtime link with UST library." 2>/dev/stderr
  36         echo "          (Needed only if program was not linked at compile time with libust.)" 2>/dev/stderr
  37         echo "    -L    Add path to ust libraries to LD_LIBRARY_PATH." 2>/dev/stderr
  38         echo "    -m    Instrument malloc calls." 2>/dev/stderr
  39         echo "    -f    Also trace forked processes." 2>/dev/stderr
  40         echo "    -s    Use system-wide daemon instead of creating one for this session." 2>/dev/stderr
  41 }
  42
  43 while getopts ":hlLmfs" options; do
  44         case $options in
  45                 l) arg_preload_libust=1;;
  46                 L) arg_ld_std_ust=1;;
  47                 m) arg_preload_malloc=1;;
  48                 f) arg_preload_fork=1;;
  49                 s) arg_syswide_daemon=1;;
  50                 h) usage;
  51                    exit 0;;
  52                 \?) usage
  53                         exit 1;;
  54                 *) usage
  55                         exit 1;;
  56         esac
  57 done
  58 shift $(($OPTIND - 1))
  59
  60 # Prepare vars
  61 CMD=$*
  62
  63 # Validate input
  64 if [ -z "$HOME" ];
  65 then
  66         error "no home specified"
  67 fi
  68
  69 if [ -z "$CMD" ];
  70 then
  71         error "no command specified"
  72         usage;
  73         exit 1
  74 fi
  75
  76 # Create directory for trace output
  77 DATESTRING="$(hostname)-$(date +%Y%m%d%H%M%S)"
  78 OUTDIR="$BASE_TRACE_DIR/$DATESTRING"
  79 mkdir -p "$OUTDIR"
  80
  81 # Choose ustd socket path
  82 USTDSOCKPATH="/tmp/ustd-sock-$$"
  83
  84 if [ "$arg_syswide_daemon" != "1" ];
  85 then
  86         pidfilepath="/tmp/usttrace-$USER-$(date +%Y%m%d%H%M%S%N)-ustd-pid"
  87         mkfifo -m 0600 "$pidfilepath"
  88         # Start daemon
  89         $USTD --pidfile "$pidfilepath" -s "$USTDSOCKPATH" -o "$OUTDIR" >"$OUTDIR/ustd.log" 2>&1 &
  90         # ustd sets up its server socket
  91         # ustd opens the pidfile, blocks because no one has opened it
  92         # we open pidfile
  93         # we block reading pidfile
  94         # ustd writes to pidfile
  95         # ustd closes pidfile
  96         # we unblock reading pidfile
  97         USTDPID="$(<$pidfilepath)"
  98         export UST_DAEMON_SOCKET="$USTDSOCKPATH"
  99 fi
 100
 101 # Establish the environment for the command
 102 (
 103     export UST_TRACE=1
 104     export UST_AUTOPROBE=1
 105
 106     if [ "$arg_preload_libust" = "1" ];
 107     then
 108         if [ -n "${LIBUST_PATH%libust.so}" ] ; then
 109             export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:${LIBUST_PATH%libust.so}"
 110         fi
 111         export LD_PRELOAD="$LD_PRELOAD:$LIBUST_PATH"
 112     fi
 113
 114     if [ "$arg_ld_std_ust" = "1" ];
 115     then
 116         if [ -n "$${LIBUST_PATH%libust.so}" ] ; then
 117             export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:${LIBUST_PATH%libust.so}"
 118         fi
 119     fi
 120
 121     if [ "$arg_preload_malloc" = "1" ];
 122     then
 123         export LD_PRELOAD="$LD_PRELOAD:$LIBMALLOCWRAP_PATH"
 124     fi
 125
 126     if [ "$arg_preload_fork" = "1" ];
 127     then
 128         export LD_PRELOAD="$LD_PRELOAD:$LIBINTERFORK_PATH"
 129     fi
 130
 131 # Install a handler for SIGIO. This is the signal that will be sent by ustd to
 132 # the traced program to trigger the creation of its listener thread. However,
 133 # it is possible that the SIGIO will be sent after the shell fork, but before
 134 # the exec of the command. If this handler isn't there, bash might terminate
 135 # because of a unhandled signal.
 136
 137 # Execute the command
 138     $CMD 2>&1
 139 ) | tee "$OUTDIR/app.log"
 140
 141 ## Because of the keepalive mechanism, we're sure that by the time
 142 ## we get here, the daemon is connected to all the buffers that still exist.
 143 ## Therefore we can politely ask it to die when it's done.
 144
 145 if [ "$arg_syswide_daemon" != "1" ];
 146 then
 147         # Tell the daemon to die
 148         kill -SIGTERM "$USTDPID"
 149
 150         echo "Waiting for ustd to shutdown..."
 151         wait "$USTDPID"
 152
 153         rm "$pidfilepath"
 154 fi
 155
 156 echo "Trace was output in: " $OUTDIR