From: Darrick J. Wong <djwong@xxxxxxxxxx> Support collecting kernel code coverage information as reported in debugfs. At the start of each section, we reset the gcov counters; during the section wrapup, we'll collect the kernel gcov data. If lcov is installed and the kernel source code is available, it will also generate a nice html report. If a CLI web browser is available, it will also format the html report into text for easy grepping. This requires the test runner to set REPORT_GCOV=1 explicitly and gcov to be enabled in the kernel. Cc: tytso@xxxxxxx Cc: kent.overstreet@xxxxxxxxx Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> --- README | 3 ++ check | 18 ++++++++++++ common/gcov | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 108 insertions(+) create mode 100644 common/gcov diff --git a/README b/README index d4ec73d10d..966ec48ed6 100644 --- a/README +++ b/README @@ -249,6 +249,9 @@ Kernel/Modules related configuration: to "forever" and we'll wait forever until the module is gone. - Set KCONFIG_PATH to specify your preferred location of kernel config file. The config is used by tests to check if kernel feature is enabled. + - Set REPORT_GCOV to a directory path to make lcov and genhtml generate + html reports from any gcov code coverage data collected by the kernel. + If REPORT_GCOV is set to 1, the report will be written to $REPORT_DIR/gcov/. Test control: - Set LOAD_FACTOR to a nonzero positive integer to increase the amount of diff --git a/check b/check index c02e693642..9741be23c4 100755 --- a/check +++ b/check @@ -451,6 +451,11 @@ _global_log() { fi } +if [ -n "$REPORT_GCOV" ]; then + . ./common/gcov + _gcov_check_report_gcov +fi + _wrapup() { seq="check" @@ -527,6 +532,18 @@ _wrapup() "${#bad[*]}" "${#notrun[*]}" \ "$((sect_stop - sect_start))" fi + + # Generate code coverage report + if [ -n "$REPORT_GCOV" ]; then + # don't trigger multiple times if caller hits ^C + local gcov_report_dir="$REPORT_GCOV" + test "$gcov_report_dir" = "1" && \ + gcov_report_dir="$REPORT_DIR/gcov" + unset REPORT_GCOV + + _gcov_generate_report "$gcov_report_dir" + fi + needwrap=false fi @@ -801,6 +818,7 @@ function run_section() echo "MOUNT_OPTIONS -- `_scratch_mount_options`" fi echo + test -n "$REPORT_GCOV" && _gcov_reset needwrap=true if [ ! -z "$SCRATCH_DEV" ]; then diff --git a/common/gcov b/common/gcov new file mode 100644 index 0000000000..b7e3ed5a93 --- /dev/null +++ b/common/gcov @@ -0,0 +1,87 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2023 Oracle. All Rights Reserved. +# +# Routines for capturing kernel code coverage reports + +GCOV_DIR=/sys/kernel/debug/gcov + +# Find the topmost directories of the .gcno directory hierarchy +__gcov_find_topdirs() { + find "${GCOV_DIR}/" -name '*.gcno' -printf '%d|%h\n' | \ + sort -g -k 1 | \ + uniq | \ + $AWK_PROG -F '|' 'BEGIN { x = -1 } { if (x < 0) x = $1; if ($1 == x) printf("%s\n", $2);}' +} + +# Generate lcov html report from kernel gcov data if configured +_gcov_generate_report() { + local output_dir="$1" + test -n "${output_dir}" || return + + # Kernel support built in? + test -d "$GCOV_DIR" || return + + readarray -t gcno_dirs < <(__gcov_find_topdirs) + test "${#gcno_dirs[@]}" -gt 0 || return + + mkdir -p "${output_dir}/raw/" + + # Collect raw coverage data from the kernel + readarray -t source_dirs < <(find "${GCOV_DIR}/" -mindepth 1 -maxdepth 1 -type d) + for dir in "${source_dirs[@]}"; do + cp -p -R -d -u "${dir}" "${output_dir}/raw/" + done + + # If lcov is installed, use it to summarize the gcda data. + # If it is not installed, there's no point in going forward + command -v lcov > /dev/null || return + local lcov=(lcov --exclude 'include*' --capture) + lcov+=(--output-file "${output_dir}/gcov.report") + for d in "${gcno_dirs[@]}"; do + lcov+=(--directory "${d}") + done + + # Generate a detailed HTML report from the summary + local gcov_start_time="$(date --date="${fstests_start_time:-now}")" + local genhtml=() + if command -v genhtml > /dev/null; then + genhtml+=(genhtml -o "${output_dir}/" "${output_dir}/gcov.report") + genhtml+=(--title "fstests on $(hostname -s) @ ${gcov_start_time}" --legend) + fi + + # Try to convert the HTML report summary as text for easier grepping if + # there's an HTML renderer present + local totext=() + test "${#totext[@]}" -eq 0 && \ + command -v lynx &>/dev/null && \ + totext=(lynx -dump "${output_dir}/index.html" -width 120 -nonumbers -nolist) + test "${#totext[@]}" -eq 0 && \ + command -v links &>/dev/null && \ + totext=(links -dump "${output_dir}/index.html" -width 120) + test "${#totext[@]}" -eq 0 && \ + command -v elinks &>/dev/null && \ + totext=(elinks -dump "${output_dir}/index.html" --dump-width 120 --no-numbering --no-references) + + # Analyze kernel data + "${lcov[@]}" > "${output_dir}/gcov.stdout" 2> "${output_dir}/gcov.stderr" + test "${#genhtml[@]}" -ne 0 && \ + "${genhtml[@]}" >> "${output_dir}/gcov.stdout" 2>> "${output_dir}/gcov.stderr" + test "${#totext[@]}" -ne 0 && \ + "${totext[@]}" > "${output_dir}/index.txt" 2>> "${output_dir}/gcov.stderr" +} + +# Reset gcov usage data +_gcov_reset() { + echo 1 > "${GCOV_DIR}/reset" +} + +# If the caller wanted us to capture gcov reports but the kernel doesn't +# support it, turn it off. +_gcov_check_report_gcov() { + test -z "$REPORT_GCOV" && return 0 + test -w "${GCOV_DIR}/reset" && return 0 + + unset REPORT_GCOV + return 1 +}