From 06a130e42a5bfc84795464bff023bff4c16f58c5 Mon Sep 17 00:00:00 2001 From: Veronika Molnarova Date: Thu, 17 Oct 2024 18:15:55 +0200 Subject: [PATCH] perf test: Handle perftool-testsuite_probe failure due to broken DWARF Test case test_adding_blacklisted ends in failure if the blacklisted probe is of an assembler function with no DWARF available. At the same time, probing the blacklisted function with ASM DWARF doesn't test the blacklist itself as the failure is a result of the broken DWARF. When the broken DWARF output is encountered, check if the probed function was compiled by the assembler. If so, the broken DWARF message is expected and does not report a perf issue, else report a failure. If the ASM DWARF affected the probe, try the next probe on the blacklist. If the first 5 probes are defective due to broken DWARF, skip the test case. Fixes: def5480d63c1e847 ("perf testsuite probe: Add test for blacklisted kprobes handling") Signed-off-by: Veronika Molnarova Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Michael Petlan Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Veronika Molnarova Link: https://lore.kernel.org/r/20241017161555.236769-1-vmolnaro@redhat.com Signed-off-by: Arnaldo Carvalho de Melo --- .../base_probe/test_adding_blacklisted.sh | 69 +++++++++++++++---- 1 file changed, 54 insertions(+), 15 deletions(-) diff --git a/tools/perf/tests/shell/base_probe/test_adding_blacklisted.sh b/tools/perf/tests/shell/base_probe/test_adding_blacklisted.sh index b5dc10b2a7381..bead723e34af3 100755 --- a/tools/perf/tests/shell/base_probe/test_adding_blacklisted.sh +++ b/tools/perf/tests/shell/base_probe/test_adding_blacklisted.sh @@ -19,35 +19,74 @@ TEST_RESULT=0 # skip if not supported -BLACKFUNC=`head -n 1 /sys/kernel/debug/kprobes/blacklist 2> /dev/null | cut -f2` -if [ -z "$BLACKFUNC" ]; then +BLACKFUNC_LIST=`head -n 5 /sys/kernel/debug/kprobes/blacklist 2> /dev/null | cut -f2` +if [ -z "$BLACKFUNC_LIST" ]; then print_overall_skipped exit 0 fi +# try to find vmlinux with DWARF debug info +VMLINUX_FILE=$(perf probe -v random_probe |& grep "Using.*for symbols" | sed -r 's/^Using (.*) for symbols$/\1/') + # remove all previously added probes clear_all_probes ### adding blacklisted function - -# functions from blacklist should be skipped by perf probe -! $CMD_PERF probe $BLACKFUNC > $LOGS_DIR/adding_blacklisted.log 2> $LOGS_DIR/adding_blacklisted.err -PERF_EXIT_CODE=$? - REGEX_SCOPE_FAIL="Failed to find scope of probe point" REGEX_SKIP_MESSAGE=" is blacklisted function, skip it\." -REGEX_NOT_FOUND_MESSAGE="Probe point \'$BLACKFUNC\' not found." +REGEX_NOT_FOUND_MESSAGE="Probe point \'$RE_EVENT\' not found." REGEX_ERROR_MESSAGE="Error: Failed to add events." REGEX_INVALID_ARGUMENT="Failed to write event: Invalid argument" REGEX_SYMBOL_FAIL="Failed to find symbol at $RE_ADDRESS" -REGEX_OUT_SECTION="$BLACKFUNC is out of \.\w+, skip it" -../common/check_all_lines_matched.pl "$REGEX_SKIP_MESSAGE" "$REGEX_NOT_FOUND_MESSAGE" "$REGEX_ERROR_MESSAGE" "$REGEX_SCOPE_FAIL" "$REGEX_INVALID_ARGUMENT" "$REGEX_SYMBOL_FAIL" "$REGEX_OUT_SECTION" < $LOGS_DIR/adding_blacklisted.err -CHECK_EXIT_CODE=$? - -print_results $PERF_EXIT_CODE $CHECK_EXIT_CODE "adding blacklisted function $BLACKFUNC" -(( TEST_RESULT += $? )) - +REGEX_OUT_SECTION="$RE_EVENT is out of \.\w+, skip it" +REGEX_MISSING_DECL_LINE="A function DIE doesn't have decl_line. Maybe broken DWARF?" + +BLACKFUNC="" +SKIP_DWARF=0 + +for BLACKFUNC in $BLACKFUNC_LIST; do + echo "Probing $BLACKFUNC" + + # functions from blacklist should be skipped by perf probe + ! $CMD_PERF probe $BLACKFUNC > $LOGS_DIR/adding_blacklisted.log 2> $LOGS_DIR/adding_blacklisted.err + PERF_EXIT_CODE=$? + + # check for bad DWARF polluting the result + ../common/check_all_patterns_found.pl "$REGEX_MISSING_DECL_LINE" >/dev/null < $LOGS_DIR/adding_blacklisted.err + + if [ $? -eq 0 ]; then + SKIP_DWARF=1 + echo "Result polluted by broken DWARF, trying another probe" + + # confirm that the broken DWARF comes from assembler + if [ -n "$VMLINUX_FILE" ]; then + readelf -wi "$VMLINUX_FILE" | + awk -v probe="$BLACKFUNC" '/DW_AT_language/ { comp_lang = $0 } + $0 ~ probe { if (comp_lang) { print comp_lang }; exit }' | + grep -q "MIPS assembler" + + CHECK_EXIT_CODE=$? + if [ $CHECK_EXIT_CODE -ne 0 ]; then + SKIP_DWARF=0 # broken DWARF while available + break + fi + fi + else + ../common/check_all_lines_matched.pl "$REGEX_SKIP_MESSAGE" "$REGEX_NOT_FOUND_MESSAGE" "$REGEX_ERROR_MESSAGE" "$REGEX_SCOPE_FAIL" "$REGEX_INVALID_ARGUMENT" "$REGEX_SYMBOL_FAIL" "$REGEX_OUT_SECTION" < $LOGS_DIR/adding_blacklisted.err + CHECK_EXIT_CODE=$? + + SKIP_DWARF=0 + break + fi +done + +if [ $SKIP_DWARF -eq 1 ]; then + print_testcase_skipped "adding blacklisted function $BLACKFUNC" +else + print_results $PERF_EXIT_CODE $CHECK_EXIT_CODE "adding blacklisted function $BLACKFUNC" + (( TEST_RESULT += $? )) +fi ### listing not-added probe -- 2.39.5