Quelle  test_brstack.sh

#!/bin/bash
# Check branch stack sampling

# SPDX-License-Identifier: GPL-2.0
# German Gomez <german.gomez@arm.com>, 2022

shelldir=$(dirname "$0")
# shellcheck source=lib/perf_has_symbol.sh
. "${shelldir}"/lib/perf_has_symbol.sh

# skip the test if the hardware doesn't support branch stack sampling
# and if the architecture doesn't support filter types: any,save_type,u
if ! perf record -o- --no-buildid --branch-filter any,save_type,u -- true > /dev/null 2>&1 ; then
 echo "skip: system doesn't support filter types: any,save_type,u"
 exit 2
fi

skip_test_missing_symbol brstack_bench

err=0
TMPDIR=$(mktemp -d /tmp/__perf_test.program.XXXXX)
TESTPROG="perf test -w brstack"

cleanup() {
 rm -rf $TMPDIR
 trap - EXIT TERM INT
}

trap_cleanup() {
 set +e
 echo "Unexpected signal in ${FUNCNAME[1]}"
 cleanup
 exit 1
}
trap trap_cleanup EXIT TERM INT

test_user_branches() {
 echo "Testing user branch stack sampling"

 perf record -o "$TMPDIR/perf.data" --branch-filter any,save_type,u -- ${TESTPROG} > "$TMPDIR/record.txt" 2>&1
 perf script -i "$TMPDIR/perf.data" --fields brstacksym > "$TMPDIR/perf.script"

 # example of branch entries:
 #  brstack_foo+0x14/brstack_bar+0x40/P/-/-/0/CALL

 expected=(
  "^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/IND_CALL/.*$"
  "^brstack_foo\+[^ ]*/brstack_bar\+[^ ]*/CALL/.*$"
  "^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/CALL/.*$"
  "^brstack_bench\+[^ ]*/brstack_bar\+[^ ]*/CALL/.*$"
  "^brstack_bar\+[^ ]*/brstack_foo\+[^ ]*/RET/.*$"
  "^brstack_foo\+[^ ]*/brstack_bench\+[^ ]*/RET/.*$"
  "^brstack_bench\+[^ ]*/brstack_bench\+[^ ]*/COND/.*$"
  "^brstack\+[^ ]*/brstack\+[^ ]*/UNCOND/.*$"
 )
 for x in "${expected[@]}"
 do
  if ! tr -s ' ' '\n' < "$TMPDIR/perf.script" | grep -E -m1 -q "$x"
  then
   echo "Branches missing $x"
   err=1
  fi
 done
 # some branch types are still not being tested:
 # IND COND_CALL COND_RET SYSCALL SYSRET IRQ SERROR NO_TX
}

# first argument <arg0> is the argument passed to "--branch-stack <arg0>,save_type,u"
# second argument are the expected branch types for the given filter
test_filter() {
 test_filter_filter=$1
 test_filter_expect=$2

 echo "Testing branch stack filtering permutation ($test_filter_filter,$test_filter_expect)"
 perf record -o "$TMPDIR/perf.data" --branch-filter "$test_filter_filter,save_type,u" -- ${TESTPROG}  > "$TMPDIR/record.txt" 2>&1
 perf script -i "$TMPDIR/perf.data" --fields brstack > "$TMPDIR/perf.script"

 # fail if we find any branch type that doesn't match any of the expected ones
 # also consider UNKNOWN branch types (-)
 if [ ! -s "$TMPDIR/perf.script" ]
 then
  echo "Empty script output"
  err=1
  return
 fi
 # Look for lines not matching test_filter_expect ignoring issues caused
 # by empty output
 tr -s ' ' '\n' < "$TMPDIR/perf.script" | grep '.' | \
   grep -E -vm1 "^[^ ]*/($test_filter_expect|-|( *))/.*$" \
   > "$TMPDIR/perf.script-filtered" || true
 if [ -s "$TMPDIR/perf.script-filtered" ]
 then
  echo "Unexpected branch filter in script output"
  cat "$TMPDIR/perf.script"
  err=1
  return
 fi
}

set -e

test_user_branches

test_filter "any_call" "CALL|IND_CALL|COND_CALL|SYSCALL|IRQ"
test_filter "call" "CALL|SYSCALL"
test_filter "cond" "COND"
test_filter "any_ret" "RET|COND_RET|SYSRET|ERET"

test_filter "call,cond"  "CALL|SYSCALL|COND"
test_filter "any_call,cond"  "CALL|IND_CALL|COND_CALL|IRQ|SYSCALL|COND"
test_filter "cond,any_call,any_ret" "COND|CALL|IND_CALL|COND_CALL|SYSCALL|IRQ|RET|COND_RET|SYSRET|ERET"

cleanup
exit $err