How can I trace the the command like cp file1 file2 using the ftrace tool?
I want to see all the functions that been called when I used cp file1 file2 but I don't know how to do it. Can anyone help me and write down the exact command in the terminal that does it?
Take the following script, you can use it to ftrace any command you want. Taken from here, I've modified slightly, you can get traced output at /tmp/mytrace.txt. Example usage: script.sh cp file1 file2
#!/bin/bash
DPATH="/sys/kernel/debug/tracing"
PID=$$
TEMP="/tmp/mytrace.txt"
## Quick basic checks
[ `id -u` -ne 0 ] && { echo "needs to be root" ; exit 1; } # check for root permissions
[ -z $1 ] && { echo "needs process name as argument" ; exit 1; } # check for args to this function
mount | grep -i debugfs &> /dev/null
[ $? -ne 0 ] && { echo "debugfs not mounted, mount it first"; exit 1; } #checks for debugfs mount
# flush existing trace data
echo nop > $DPATH/current_tracer
# set function tracer
echo function_graph > $DPATH/current_tracer
# enable the current tracer
#echo 1 > $DPATH/tracing_on
# write current process id to set_ftrace_pid file
echo $PID > $DPATH/set_ftrace_pid
# start the tracing
echo 1 > $DPATH/tracing_on
# execute the process
exec $* > /dev/null 2>&1 &
#echo "$*"
`cat $DPATH/trace > $TEMP`
echo 0 > $DPATH/tracing_on
echo nop > $DPATH/current_tracer
