From: Namhyung Kim <namhyung@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>,
Ian Rogers <irogers@google.com>,
Kan Liang <kan.liang@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-perf-users@vger.kernel.org, Sally Shi <sshii@google.com>
Subject: [PATCH] perf bpf-filter: Fix a parsing error with comma
Date: Fri, 7 Mar 2025 14:09:21 -0800 [thread overview]
Message-ID: <20250307220922.434319-1-namhyung@kernel.org> (raw)
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 [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]
--filter <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.
Fixes: 91e88437d5156b20 ("perf bpf-filter: Support filtering on cgroups")
Reported-by: Sally Shi <sshii@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
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 1b58ccc1fd882d1d..4d6c3c1b7fb92579 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 f313404f95a90d25..6aa65ade33851bfc 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.rc0.332.g42c0ae87b1-goog
next reply other threads:[~2025-03-07 22:09 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-07 22:09 Namhyung Kim [this message]
2025-03-25 19:49 ` [PATCH] perf bpf-filter: Fix a parsing error with comma Namhyung Kim
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250307220922.434319-1-namhyung@kernel.org \
--to=namhyung@kernel.org \
--cc=acme@kernel.org \
--cc=adrian.hunter@intel.com \
--cc=irogers@google.com \
--cc=jolsa@kernel.org \
--cc=kan.liang@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=sshii@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).