Commit eb50d0f2 authored by Masami Hiramatsu (Google)'s avatar Masami Hiramatsu (Google)
Browse files

selftests/ftrace: Choose target function for filter test from samples 

Since the event-filter-function.tc expects the 'exit_mmap()' directly
calls 'kmem_cache_free()', this is vulnerable to code modifications.

Choose the target function for the filter test from the sample
event data so that it can keep test running correctly even if the caller
function name will be changed.

Link: https://lore.kernel.org/linux-trace-kernel/167919441260.1922645.18355804179347364057.stgit@mhiramat.roam.corp.google.com/

Link: https://lore.kernel.org/all/CA+G9fYtF-XEKi9YNGgR=Kf==7iRb2FrmEC7qtwAeQbfyah-UhA@mail.gmail.com/


Reported-by: default avatarLinux Kernel Functional Testing <lkft@linaro.org>
Fixes: 7f09d639 ("tracing/selftests: Add test for event filtering on function name")
Signed-off-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 81d0fa4c

tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc

+27 −18
Original line number Diff line number Diff line
@@ -9,18 +9,33 @@ fail() { #msg 
    exit_fail

}



echo "Test event filter function name"

echo 0 > tracing_on

echo 0 > events/enable

sample_events() {

    echo > trace

echo 'call_site.function == exit_mmap' > events/kmem/kmem_cache_free/filter

    echo 1 > events/kmem/kmem_cache_free/enable

    echo 1 > tracing_on

    ls > /dev/null

    echo 0 > tracing_on

    echo 0 > events/kmem/kmem_cache_free/enable

}



hitcnt=`grep kmem_cache_free trace| grep exit_mmap | wc -l`

misscnt=`grep kmem_cache_free trace| grep -v exit_mmap | wc -l`

echo 0 > tracing_on

echo 0 > events/enable



echo "Get the most frequently calling function"

sample_events



target_func=`cut -d: -f3 trace | sed 's/call_site=\([^+]*\)+0x.*/\1/' | sort | uniq -c | sort | tail -n 1 | sed 's/^[ 0-9]*//'`

if [ -z "$target_func" ]; then

    exit_fail

fi

echo > trace



echo "Test event filter function name"

echo "call_site.function == $target_func" > events/kmem/kmem_cache_free/filter

sample_events



hitcnt=`grep kmem_cache_free trace| grep $target_func | wc -l`

misscnt=`grep kmem_cache_free trace| grep -v $target_func | wc -l`



if [ $hitcnt -eq 0 ]; then

	exit_fail
@@ -30,20 +45,14 @@ if [ $misscnt -gt 0 ]; then 
	exit_fail

fi



address=`grep ' exit_mmap$' /proc/kallsyms | cut -d' ' -f1`

address=`grep " ${target_func}\$" /proc/kallsyms | cut -d' ' -f1`



echo "Test event filter function address"

echo 0 > tracing_on

echo 0 > events/enable

echo > trace

echo "call_site.function == 0x$address" > events/kmem/kmem_cache_free/filter

echo 1 > events/kmem/kmem_cache_free/enable

echo 1 > tracing_on

sleep 1

echo 0 > events/kmem/kmem_cache_free/enable

sample_events



hitcnt=`grep kmem_cache_free trace| grep exit_mmap | wc -l`

misscnt=`grep kmem_cache_free trace| grep -v exit_mmap | wc -l`

hitcnt=`grep kmem_cache_free trace| grep $target_func | wc -l`

misscnt=`grep kmem_cache_free trace| grep -v $target_func | wc -l`



if [ $hitcnt -eq 0 ]; then

	exit_fail