From 35d13f841a3d8159ef20d5e32a9ed3faa27875bc Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Fri, 7 Mar 2025 14:09:21 -0800 Subject: [PATCH] perf bpf-filter: Fix a parsing error with comma The previous change to support cgroup filters introduced a bug that pathname can include commas. It confused the lexer to treat an item and the trailing comma as a single token. And it resulted in a parse error: $ sudo perf record -e cycles:P --filter 'period > 0, ip > 64' -- true perf_bpf_filter: Error: Unexpected item: 0, perf_bpf_filter: syntax error, unexpected BFT_ERROR, expecting BFT_NUM Usage: perf record [] [] or: perf record [] -- [] --filter event filter It should get "0" and "," separately. An easiest fix would be to remove "," from the possible pathname characters. As it's for cgroup names, probably ok to assume it won't have commas in the pathname. I found that the existing BPF filtering test didn't have any complex filter condition with commas. Let's update the group filter test which is supposed to test filter combinations like this. Link: https://lore.kernel.org/r/20250307220922.434319-1-namhyung@kernel.org Fixes: 91e88437d5156b20 ("perf bpf-filter: Support filtering on cgroups") Reported-by: Sally Shi Signed-off-by: Namhyung Kim --- tools/perf/tests/shell/record_bpf_filter.sh | 4 ++-- tools/perf/util/bpf-filter.l | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/perf/tests/shell/record_bpf_filter.sh b/tools/perf/tests/shell/record_bpf_filter.sh index 1b58ccc1fd88..4d6c3c1b7fb9 100755 --- a/tools/perf/tests/shell/record_bpf_filter.sh +++ b/tools/perf/tests/shell/record_bpf_filter.sh @@ -89,7 +89,7 @@ test_bpf_filter_fail() { test_bpf_filter_group() { echo "Group bpf-filter test" - if ! perf record -e task-clock --filter 'period > 1000 || ip > 0' \ + if ! perf record -e task-clock --filter 'period > 1000, ip > 0' \ -o /dev/null true 2>/dev/null then echo "Group bpf-filter test [Failed should succeed]" @@ -97,7 +97,7 @@ test_bpf_filter_group() { return fi - if ! perf record -e task-clock --filter 'cpu > 0 || ip > 0' \ + if ! perf record -e task-clock --filter 'period > 1000 , cpu > 0 || ip > 0' \ -o /dev/null true 2>&1 | grep -q PERF_SAMPLE_CPU then echo "Group bpf-filter test [Failed forbidden CPU]" diff --git a/tools/perf/util/bpf-filter.l b/tools/perf/util/bpf-filter.l index f313404f95a9..6aa65ade3385 100644 --- a/tools/perf/util/bpf-filter.l +++ b/tools/perf/util/bpf-filter.l @@ -76,7 +76,7 @@ static int path_or_error(void) num_dec [0-9]+ num_hex 0[Xx][0-9a-fA-F]+ space [ \t]+ -path [^ \t\n]+ +path [^ \t\n,]+ ident [_a-zA-Z][_a-zA-Z0-9]+ %% -- 2.49.0