On Tue, Jul 25, 2023 at 06:56:51PM -0700, Darrick J. Wong wrote:
> 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>
> ---
This version looks good to me,
Reviewed-by: Zorro Lang <zlang@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
> +}
>
