1#!/bin/sh 2# Check branch stack sampling 3 4# SPDX-License-Identifier: GPL-2.0 5# German Gomez <german.gomez@arm.com>, 2022 6 7# we need a C compiler to build the test programs 8# so bail if none is found 9if ! [ -x "$(command -v cc)" ]; then 10 echo "failed: no compiler, install gcc" 11 exit 2 12fi 13 14# skip the test if the hardware doesn't support branch stack sampling 15# and if the architecture doesn't support filter types: any,save_type,u 16if ! perf record -o- --no-buildid --branch-filter any,save_type,u -- true > /dev/null 2>&1 ; then 17 echo "skip: system doesn't support filter types: any,save_type,u" 18 exit 2 19fi 20 21TMPDIR=$(mktemp -d /tmp/__perf_test.program.XXXXX) 22 23cleanup() { 24 rm -rf $TMPDIR 25} 26 27trap cleanup exit term int 28 29gen_test_program() { 30 # generate test program 31 cat << EOF > $1 32#define BENCH_RUNS 999999 33int cnt; 34void bar(void) { 35} /* return */ 36void foo(void) { 37 bar(); /* call */ 38} /* return */ 39void bench(void) { 40 void (*foo_ind)(void) = foo; 41 if ((cnt++) % 3) /* branch (cond) */ 42 foo(); /* call */ 43 bar(); /* call */ 44 foo_ind(); /* call (ind) */ 45} 46int main(void) 47{ 48 int cnt = 0; 49 while (1) { 50 if ((cnt++) > BENCH_RUNS) 51 break; 52 bench(); /* call */ 53 } /* branch (uncond) */ 54 return 0; 55} 56EOF 57} 58 59test_user_branches() { 60 echo "Testing user branch stack sampling" 61 62 gen_test_program "$TEMPDIR/program.c" 63 cc -fno-inline -g "$TEMPDIR/program.c" -o $TMPDIR/a.out 64 65 perf record -o $TMPDIR/perf.data --branch-filter any,save_type,u -- $TMPDIR/a.out > /dev/null 2>&1 66 perf script -i $TMPDIR/perf.data --fields brstacksym | xargs -n1 > $TMPDIR/perf.script 67 68 # example of branch entries: 69 # foo+0x14/bar+0x40/P/-/-/0/CALL 70 71 set -x 72 egrep -m1 "^bench\+[^ ]*/foo\+[^ ]*/IND_CALL$" $TMPDIR/perf.script 73 egrep -m1 "^foo\+[^ ]*/bar\+[^ ]*/CALL$" $TMPDIR/perf.script 74 egrep -m1 "^bench\+[^ ]*/foo\+[^ ]*/CALL$" $TMPDIR/perf.script 75 egrep -m1 "^bench\+[^ ]*/bar\+[^ ]*/CALL$" $TMPDIR/perf.script 76 egrep -m1 "^bar\+[^ ]*/foo\+[^ ]*/RET$" $TMPDIR/perf.script 77 egrep -m1 "^foo\+[^ ]*/bench\+[^ ]*/RET$" $TMPDIR/perf.script 78 egrep -m1 "^bench\+[^ ]*/bench\+[^ ]*/COND$" $TMPDIR/perf.script 79 egrep -m1 "^main\+[^ ]*/main\+[^ ]*/UNCOND$" $TMPDIR/perf.script 80 set +x 81 82 # some branch types are still not being tested: 83 # IND COND_CALL COND_RET SYSCALL SYSRET IRQ SERROR NO_TX 84} 85 86# first argument <arg0> is the argument passed to "--branch-stack <arg0>,save_type,u" 87# second argument are the expected branch types for the given filter 88test_filter() { 89 local filter=$1 90 local expect=$2 91 92 echo "Testing branch stack filtering permutation ($filter,$expect)" 93 94 gen_test_program "$TEMPDIR/program.c" 95 cc -fno-inline -g "$TEMPDIR/program.c" -o $TMPDIR/a.out 96 97 perf record -o $TMPDIR/perf.data --branch-filter $filter,save_type,u -- $TMPDIR/a.out > /dev/null 2>&1 98 perf script -i $TMPDIR/perf.data --fields brstack | xargs -n1 > $TMPDIR/perf.script 99 100 # fail if we find any branch type that doesn't match any of the expected ones 101 # also consider UNKNOWN branch types (-) 102 if egrep -vm1 "^[^ ]*/($expect|-|( *))$" $TMPDIR/perf.script; then 103 return 1 104 fi 105} 106 107set -e 108 109test_user_branches 110 111test_filter "any_call" "CALL|IND_CALL|COND_CALL|SYSCALL|IRQ" 112test_filter "call" "CALL|SYSCALL" 113test_filter "cond" "COND" 114test_filter "any_ret" "RET|COND_RET|SYSRET|ERET" 115 116test_filter "call,cond" "CALL|SYSCALL|COND" 117test_filter "any_call,cond" "CALL|IND_CALL|COND_CALL|IRQ|SYSCALL|COND" 118test_filter "cond,any_call,any_ret" "COND|CALL|IND_CALL|COND_CALL|SYSCALL|IRQ|RET|COND_RET|SYSRET|ERET" 119