etrace

#!/bin/bash

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

print_usage () {
    echo "Usage: etrace [-h] [-l] [-a] [-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="ignore_repeated_opens=1"

while getopts "ahlw:" opt; do
    case "$opt" in
    h)
        print_usage
        exit 0
        ;;
    l)
        SAVE_KERNEL_LOG=y
        ;;
    w)
        WORK_DIR="$OPTARG"
        mkdir -p "$WORK_DIR"
        ;;
    a)
        MODULE_PARAMS=""
        ;;
    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
sudo -n setup_etrace.sh -f
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="$!"
sudo -n renice -n -18 -p $LISTENER_PID

# -------- save kernel log
if [ "$SAVE_KERNEL_LOG" = "y" ]; then
    dmesg -w > "$WORK_DIR/.nfsdb.klog" &
    KLOGGER_PID="$!"
fi

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

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

# -------- remove execve_trace module
sudo -n setup_etrace.sh -r
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
kill -SIGINT "${LISTENER_PID}"

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

# We're done here
exit $RV