tracing/selftests: Add tests for hist trigger expression parsing

Add tests for the parsing of hist trigger expressions; and to
validate expression evaluation.

Link: https://lkml.kernel.org/r/20211029183339.3216491-5-kaleshsingh@google.com

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Kalesh Singh 2021-10-29 11:33:30 -07:00 committed by Steven Rostedt (VMware)
parent 6a6e5ef2b2
commit 4e9f63c9e5

View File

@ -0,0 +1,63 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# description: event trigger - test histogram expression parsing
# requires: set_event events/sched/sched_process_fork/trigger events/sched/sched_process_fork/hist error_log "<var1>=<field|var_ref|numeric_literal>":README
fail() { #msg
echo $1
exit_fail
}
test_hist_expr() { # test_name expression expected_val
trigger="events/sched/sched_process_fork/trigger"
reset_trigger_file $trigger
echo "Test hist trigger expressions - $1"
echo "hist:keys=common_pid:x=$2" > $trigger
for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done
actual=`grep -o 'x=[[:digit:]]*' $trigger | awk -F= '{ print $2 }'`
if [ $actual != $3 ]; then
fail "Failed hist trigger expression evaluation: Expression: $2 Expected: $3, Actual: $actual"
fi
reset_trigger_file $trigger
}
check_error() { # test_name command-with-error-pos-by-^
trigger="events/sched/sched_process_fork/trigger"
echo "Test hist trigger expressions - $1"
ftrace_errlog_check 'hist:sched:sched_process_fork' "$2" $trigger
}
test_hist_expr "Variable assignment" "123" "123"
test_hist_expr "Subtraction not associative" "16-8-4-2" "2"
test_hist_expr "Division not associative" "64/8/4/2" "1"
test_hist_expr "Same precedence operators (+,-) evaluated left to right" "16-8+4+2" "14"
test_hist_expr "Same precedence operators (*,/) evaluated left to right" "4*3/2*2" "12"
test_hist_expr "Multiplication evaluated before addition/subtraction" "4+3*2-2" "8"
test_hist_expr "Division evaluated before addition/subtraction" "4+6/2-2" "5"
# err pos for "too many subexpressions" is dependent on where
# the last subexpression was detected. This can vary depending
# on how the expression tree was generated.
check_error "Too many subexpressions" 'hist:keys=common_pid:x=32+^10*3/20-4'
check_error "Too many subexpressions" 'hist:keys=common_pid:x=^1+2+3+4+5'
check_error "Unary minus not supported in subexpression" 'hist:keys=common_pid:x=-(^1)+2'
check_error "Division by zero" 'hist:keys=common_pid:x=3/^0'
exit 0