etrace

#!/bin/bash

# Run syscalls tracing of a given command
# Usage:
# etrace COMMAND ...

print_usage () {
    echo "Usage: etrace [-hlimte] [-w WORK_DIR] [--] COMMAND ..."
}

echo_err () {
    echo "[!] $1"
}

if [ "$#" -lt 1 ]; then
    print_usage
    exit 1
fi

# -------- parse args
SAVE_KERNEL_LOG=
WORK_DIR=$(pwd)
INITCWD=$(pwd)
MODULE_PARAMS=""

while getopts "hilmtew:" opt; do
    case "$opt" in
    h)
        print_usage
        exit 0
        ;;
    l)
        SAVE_KERNEL_LOG=y
        ;;
    w)
        WORK_DIR="$OPTARG"
        mkdir -p "$WORK_DIR"
        ;;
    i)
        MODULE_PARAMS="$MODULE_PARAMS ignore_repeated_opens=1"
        ;;
    t)
        MODULE_PARAMS="$MODULE_PARAMS trace_thread_names=1"
        ;;
    m)
        MODULE_PARAMS="$MODULE_PARAMS enable_mount=1"
        ;;
    e)
        MODULE_PARAMS="$MODULE_PARAMS trace_env_vars=1"
        ;;
    esac
done

# Remove script's arguments so that "$@" contains the command to run
# under tracer
shift $((OPTIND-1))
# If arguments were separated from the command by "--", remove it too
[ "${1:-}" = "--" ] && shift


DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
NPROC=$(nproc)
NPROC=$(expr $NPROC - 1)

# -------- setting up ftrace
if (( $EUID != 0 )); then
    sudo -n setup_etrace.sh -f
else
    setup_etrace.sh -f
fi
if [ "$?" -ne 0 ]; then
    echo_err "setup_etrace.sh -f failed"
    exit 1
fi

# -------- save our CWD
echo "INITCWD=$INITCWD" > "$WORK_DIR/.nfsdb"

# -------- set up event listener
#${DIR}/etrace_cat "/sys/kernel/debug/tracing/trace_pipe" > "$WORK_DIR/.nfsdb" &
${DIR}/cati "/sys/kernel/debug/tracing/trace_pipe" >> "$WORK_DIR/.nfsdb" &
LISTENER_PID="$!"
if (( $EUID != 0 )); then
    sudo -n renice -n -18 -p $LISTENER_PID >/dev/null 2>&1
else
    renice -n -18 -p $LISTENER_PID >/dev/null 2>&1
fi
# -------- save kernel log
if [ "$SAVE_KERNEL_LOG" = "y" ]; then
    dmesg -w > "$WORK_DIR/.nfsdb.klog" &
    KLOGGER_PID="$!"
fi

# -------- install bas_tracer module
MYPID="$$"
if (( $EUID != 0 )); then
    sudo -n setup_etrace.sh -i $MYPID $MODULE_PARAMS
else
    setup_etrace.sh -i $MYPID $MODULE_PARAMS
fi
if [ "$?" -ne 0 ]; then
    echo_err "setup_etrace.sh -i failed"
    exit 1
fi

# -------- run the command
"$@"
RV="$?"

# -------- remove bas_tracer module
if (( $EUID != 0 )); then
    sudo -n setup_etrace.sh -r
else
    setup_etrace.sh -r
fi
if [ "$?" -ne 0 ]; then
    echo_err "setup_etrace.sh -r failed"
    exit 1
fi

# Save stat information to see if any events have been missing
rm -f "$WORK_DIR/.nfsdb.stats" && touch "$WORK_DIR/.nfsdb.stats"
for i in `seq 0 $NPROC`; do
    echo "##---------- CPU $i ---------- ##" >> "$WORK_DIR/.nfsdb.stats"
    cat "/sys/kernel/debug/tracing/per_cpu/cpu$i/stats" >> "$WORK_DIR/.nfsdb.stats"
done

# -------- stop event listener
if [ -f "${WORK_DIR}/.nfsdb" ]; then
    PREV_LINE=`tail -n 1 ${WORK_DIR}/.nfsdb`
    sleep 2
    CURR_LINE=`tail -n 1 ${WORK_DIR}/.nfsdb`
    while [ "${PREV_LINE}" != "${CURR_LINE}" ]; do
        PREV_LINE=${CURR_LINE}
        sleep 2
        CURR_LINE=`tail -n 1 ${WORK_DIR}/.nfsdb`
    done
fi

kill -SIGINT "${LISTENER_PID}"

# -------- stop kernel logger
if [ "$SAVE_KERNEL_LOG" = "y" ]; then
    kill -SIGINT "${KLOGGER_PID}"
fi

# We're done here
exit $RV