Re: [PATCH v3 1/2] perf trace: Add tests for BTF general augmentation

[Namhyung Kim <namhyung@kernel.org>]

Hi Howard,

On Wed, Dec 11, 2024 at 02:49:26PM -0800, Howard Chu wrote:
> Currently, we only have perf trace augmentation tests for enum
> arguments. This patch adds tests for more general syscall arguments,
> such as struct pointers, strings, and buffers.
> 
> These tests utilize the perf config system to configure the perf trace
> output, as suggested by Arnaldo Carvalho de Melo <acme@kernel.org>
> 
> Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
> Signed-off-by: Howard Chu <howardchu95@gmail.com>
> ---
>  tools/perf/tests/shell/trace_btf_general.sh | 93 +++++++++++++++++++++
>  1 file changed, 93 insertions(+)
>  create mode 100755 tools/perf/tests/shell/trace_btf_general.sh
> 
> diff --git a/tools/perf/tests/shell/trace_btf_general.sh b/tools/perf/tests/shell/trace_btf_general.sh
> new file mode 100755
> index 000000000000..bef07bad42bb
> --- /dev/null
> +++ b/tools/perf/tests/shell/trace_btf_general.sh
> @@ -0,0 +1,93 @@
> +#!/bin/bash
> +# perf trace BTF general tests
> +# SPDX-License-Identifier: GPL-2.0
> +
> +err=0
> +set -e
> +
> +. "$(dirname $0)"/lib/probe.sh
> +
> +file1=$(mktemp /tmp/file1_XXXX)
> +file2=$(echo $file1 | sed 's/file1/file2/g')
> +
> +buffer="buffer content"
> +perf_config_tmp=$(mktemp /tmp/.perfconfig_XXXXX)
> +
> +trap cleanup EXIT TERM INT HUP
> +
> +check_vmlinux() {
> +  echo "Checking if vmlinux BTF exists"
> +  if ! ls /sys/kernel/btf/vmlinux 1>/dev/null 2>&1

Normally we do

  if [ ! -f /sys/kernel/btf/vmlinux ]

> +  then
> +    echo "Skipped due to missing vmlinux BTF"
> +    err=2

This can be overwritten by trace_test_string.


> +  fi
> +}
> +
> +trace_test_string() {
> +  echo "Testing perf trace's string augmentation"
> +  if ! perf trace -e renameat* --max-events=1 -- mv ${file1} ${file2} 2>&1 | \
> +    grep -q -E "^mv/[0-9]+ renameat(2)?\(.*, \"${file1}\", .*, \"${file2}\", .*\) += +[0-9]+$"

Does this work without BTF support?

Thanks
Namhyung


> +  then
> +    echo "String augmentation test failed"
> +    err=1
> +  fi
> +}
> +
> +trace_test_buffer() {
> +  echo "Testing perf trace's buffer augmentation"
> +  # echo will insert a newline (\10) at the end of the buffer
> +  if ! perf trace -e write --max-events=1 -- echo "${buffer}" 2>&1 | \
> +    grep -q -E "^echo/[0-9]+ write\([0-9]+, ${buffer}.*, [0-9]+\) += +[0-9]+$"
> +  then
> +    echo "Buffer augmentation test failed"
> +    err=1
> +  fi
> +}
> +
> +trace_test_struct_btf() {
> +  echo "Testing perf trace's struct augmentation"
> +  if ! perf trace -e clock_nanosleep --force-btf --max-events=1 -- sleep 1 2>&1 | \
> +    grep -q -E "^sleep/[0-9]+ clock_nanosleep\(0, 0, \{1,\}, 0x[0-9a-f]+\) += +[0-9]+$"
> +  then
> +    echo "BTF struct augmentation test failed"
> +    err=1
> +  fi
> +}
> +
> +cleanup() {
> +  rm -rf ${file1} ${file2} ${perf_config_tmp}
> +}
> +
> +trap_cleanup() {
> +  echo "Unexpected signal in ${FUNCNAME[1]}"
> +  cleanup
> +  exit 1
> +}
> +
> +# don't overwrite user's perf config
> +trace_config() {
> +  export PERF_CONFIG=${perf_config_tmp}
> +  perf config trace.show_arg_names=false trace.show_duration=false \
> +    trace.show_timestamp=false trace.args_alignment=0
> +}
> +
> +skip_if_no_perf_trace || exit 2
> +
> +check_vmlinux
> +
> +trace_config
> +
> +trace_test_string
> +
> +if [ $err = 0 ]; then
> +  trace_test_buffer
> +fi
> +
> +if [ $err = 0 ]; then
> +  trace_test_struct_btf
> +fi
> +
> +cleanup
> +
> +exit $err
> -- 
> 2.43.0
>