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: $1" 2>/dev/stderr
   8 }
   9
  10 function sighandler() {
  11         echo "Caught Ctrl-C"
  12         if [ -z "$USTDPID" ]; then
  13                 USTDPID="$(<$pidfilepath)"
  14         fi
  15         # Tell the daemon to die
  16         kill -SIGTERM "$USTDPID"
  17
  18         echo "Waiting for ustd to shutdown..."
  19         wait "$USTDPID"
  20
  21         rm "$pidfilepath"
  22
  23         exit 0;
  24 }
  25
  26 USTTRACE_DIR="$(dirname $0)"
  27 if [ -x "${USTTRACE_DIR}/ustd/ustd" ] ; then
  28     # Use the not installed libraries instead
  29     USTD="${USTTRACE_DIR}/ustd/ustd"
  30     LIBINTERFORK_PATH="${USTTRACE_DIR}/libinterfork/.libs/libinterfork.so"
  31     LIBMALLOCWRAP_PATH="${USTTRACE_DIR}/libmallocwrap/.libs/libmallocwrap.so"
  32     LIBUST_PATH="${USTTRACE_DIR}/libust/.libs/libust.so"
  33 else
  34     # Use the libraries that the dynamic link finds
  35     USTD="ustd"
  36     if [ ! -x "$(which ustd 2>/dev/null)" ]; then
  37         error "cannot find an executable ustd; make sure its location is in the PATH"
  38         exit 1
  39     fi
  40     LIBINTERFORK_PATH="libinterfork.so"
  41     LIBMALLOCWRAP_PATH="libmallocwrap.so"
  42     LIBUST_PATH="libust.so.0"
  43 fi
  44
  45 BASE_TRACE_DIR="${HOME}/.usttraces"
  46
  47 function usage () {
  48         echo "usage:  $0 OPTIONS COMMAND" 2>/dev/stderr
  49         echo "" 2>/dev/stderr
  50         echo "Options:" 2>/dev/stderr
  51         echo "    -l    Runtime link with UST library." 2>/dev/stderr
  52         echo "          (Needed only if program was not linked at compile time with libust.)" 2>/dev/stderr
  53         echo "    -L    Add path to ust libraries to LD_LIBRARY_PATH." 2>/dev/stderr
  54         echo "    -m    Instrument malloc calls." 2>/dev/stderr
  55         echo "    -f    Also trace forked processes." 2>/dev/stderr
  56         echo "    -s    Use system-wide daemon instead of creating one for this session." 2>/dev/stderr
  57 }
  58
  59 while getopts ":hlLmfs" options; do
  60         case $options in
  61                 l) arg_preload_libust=1;;
  62                 L) arg_ld_std_ust=1;;
  63                 m) arg_preload_malloc=1;;
  64                 f) arg_preload_fork=1;;
  65                 s) arg_syswide_daemon=1;;
  66                 h) usage;
  67                    exit 0;;
  68                 \?) usage
  69                         exit 1;;
  70                 *) usage
  71                         exit 1;;
  72         esac
  73 done
  74 shift $(($OPTIND - 1))
  75
  76 # Prepare vars
  77 CMD=$*
  78
  79 # Validate input
  80 if [ -z "$HOME" ];
  81 then
  82         error "no home specified"
  83 fi
  84
  85 if [ -z "$CMD" ];
  86 then
  87         error "no command specified"
  88         usage;
  89         exit 1
  90 fi
  91
  92 # Create directory for trace output
  93 DATESTRING="$(hostname)-$(date +%Y%m%d%H%M%S)"
  94 OUTDIR="$BASE_TRACE_DIR/$DATESTRING"
  95 mkdir -p "$OUTDIR"
  96
  97 # Choose ustd socket path
  98 USTDSOCKPATH="/tmp/ustd-sock-$$"
  99
 100 if [ "$arg_syswide_daemon" != "1" ];
 101 then
 102         pidfilepath="/tmp/usttrace-$USER-$(date +%Y%m%d%H%M%S%N)-ustd-pid"
 103         trap "sighandler $pidfilepath" SIGINT
 104         mkfifo -m 0600 "$pidfilepath"
 105         # Start daemon
 106         $USTD --pidfile "$pidfilepath" -s "$USTDSOCKPATH" -o "$OUTDIR" >"$OUTDIR/ustd.log" 2>&1 &
 107         # ustd sets up its server socket
 108         # ustd opens the pidfile, blocks because no one has opened it
 109         # we open pidfile
 110         # we block reading pidfile
 111         # ustd writes to pidfile
 112         # ustd closes pidfile
 113         # we unblock reading pidfile
 114         USTDPID="$(<$pidfilepath)"
 115         export UST_DAEMON_SOCKET="$USTDSOCKPATH"
 116 fi
 117
 118 # Establish the environment for the command
 119 (
 120     export UST_TRACE=1
 121     export UST_AUTOPROBE=1
 122
 123     if [ "$arg_preload_libust" = "1" ];
 124     then
 125         if [ -n "${LIBUST_PATH%libust.so}" ] ; then
 126             export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:${LIBUST_PATH%libust.so}"
 127         fi
 128         export LD_PRELOAD="$LD_PRELOAD:$LIBUST_PATH"
 129     fi
 130
 131     if [ "$arg_ld_std_ust" = "1" ];
 132     then
 133         if [ -n "$${LIBUST_PATH%libust.so}" ] ; then
 134             export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:${LIBUST_PATH%libust.so}"
 135         fi
 136     fi
 137
 138     if [ "$arg_preload_malloc" = "1" ];
 139     then
 140         export LD_PRELOAD="$LD_PRELOAD:$LIBMALLOCWRAP_PATH"
 141     fi
 142
 143     if [ "$arg_preload_fork" = "1" ];
 144     then
 145         export LD_PRELOAD="$LD_PRELOAD:$LIBINTERFORK_PATH"
 146     fi
 147
 148 # Install a handler for SIGIO. This is the signal that will be sent by ustd to
 149 # the traced program to trigger the creation of its listener thread. However,
 150 # it is possible that the SIGIO will be sent after the shell fork, but before
 151 # the exec of the command. If this handler isn't there, bash might terminate
 152 # because of a unhandled signal.
 153
 154 # Execute the command
 155     $CMD 2>&1
 156 ) | tee "$OUTDIR/app.log"
 157
 158 ## Because of the keepalive mechanism, we're sure that by the time
 159 ## we get here, the daemon is connected to all the buffers that still exist.
 160 ## Therefore we can politely ask it to die when it's done.
 161
 162 if [ "$arg_syswide_daemon" != "1" ];
 163 then
 164         # Tell the daemon to die
 165         kill -SIGTERM "$USTDPID"
 166
 167         echo "Waiting for ustd to shutdown..."
 168         wait "$USTDPID"
 169
 170         rm "$pidfilepath"
 171 fi
 172
 173 echo "Trace was output in: " $OUTDIR