From: Ian Rogers <irogers@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Kan Liang <kan.liang@linux.intel.com>,
Andi Kleen <ak@linux.intel.com>,
Haiyan Song <haiyanx.song@intel.com>,
Jin Yao <yao.jin@linux.intel.com>,
Song Liu <songliubraving@fb.com>,
Ravi Bangoria <ravi.bangoria@linux.ibm.com>,
John Garry <john.garry@huawei.com>, Leo Yan <leo.yan@linaro.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Paul Clarke <pc@us.ibm.com>,
linux-kernel@vger.kernel.org, kajoljain <kjain@linux.ibm.com>,
linux-perf-users@vger.kernel.org
Cc: Stephane Eranian <eranian@google.com>, Ian Rogers <irogers@google.com>
Subject: [PATCH v4 10/12] perf expr: print a debug message for division by zero
Date: Fri, 1 May 2020 10:33:31 -0700 [thread overview]
Message-ID: <20200501173333.227162-11-irogers@google.com> (raw)
In-Reply-To: <20200501173333.227162-1-irogers@google.com>
If an expression yields 0 and is then divided-by/modulus-by then the
parsing aborts. Add a debug error message to better enable debugging
when this happens.
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/expr.y | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index 54260094b947..21e82a1e11a2 100644
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -103,8 +103,18 @@ expr: NUMBER
| expr '+' expr { $$ = $1 + $3; }
| expr '-' expr { $$ = $1 - $3; }
| expr '*' expr { $$ = $1 * $3; }
- | expr '/' expr { if ($3 == 0) YYABORT; $$ = $1 / $3; }
- | expr '%' expr { if ((long)$3 == 0) YYABORT; $$ = (long)$1 % (long)$3; }
+ | expr '/' expr { if ($3 == 0) {
+ pr_debug("division by zero\n");
+ YYABORT;
+ }
+ $$ = $1 / $3;
+ }
+ | expr '%' expr { if ((long)$3 == 0) {
+ pr_debug("division by zero\n");
+ YYABORT;
+ }
+ $$ = (long)$1 % (long)$3;
+ }
| '-' expr %prec NEG { $$ = -$2; }
| '(' if_expr ')' { $$ = $2; }
| MIN '(' expr ',' expr ')' { $$ = $3 < $5 ? $3 : $5; }
--
2.26.2.526.g744177e7f7-goog
next prev parent reply other threads:[~2020-05-01 17:34 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-01 17:33 [PATCH v4 00/12] perf metric fixes and test Ian Rogers
2020-05-01 17:33 ` [PATCH v4 01/12] perf expr: unlimited escaped characters in a symbol Ian Rogers
2020-05-04 6:48 ` kajoljain
2020-05-01 17:33 ` [PATCH v4 02/12] perf metrics: fix parse errors in cascade lake metrics Ian Rogers
2020-05-01 17:33 ` [PATCH v4 03/12] perf metrics: fix parse errors in skylake metrics Ian Rogers
2020-05-01 17:33 ` [PATCH v4 04/12] perf expr: allow ',' to be an other token Ian Rogers
2020-05-01 17:33 ` [PATCH v4 05/12] perf expr: increase max other Ian Rogers
2020-05-01 17:33 ` [PATCH v4 06/12] perf expr: parse numbers as doubles Ian Rogers
2020-05-04 6:50 ` kajoljain
2020-05-01 17:33 ` [PATCH v4 07/12] perf expr: debug lex if debugging yacc Ian Rogers
2020-05-01 17:33 ` [PATCH v4 08/12] perf metrics: fix parse errors in power8 metrics Ian Rogers
2020-05-01 17:33 ` [PATCH v4 09/12] perf metrics: fix parse errors in power9 metrics Ian Rogers
2020-05-01 17:33 ` Ian Rogers [this message]
2020-05-01 17:33 ` [PATCH v4 11/12] perf parse-events: expand add PMU error/verbose messages Ian Rogers
2020-05-01 17:33 ` [PATCH v4 12/12] perf test: improve pmu event metric testing Ian Rogers
[not found] ` <20200503145553.GA1865281@krava>
[not found] ` <CAP-5=fXrwcz+MMF0Dqd_UnoXoTo1iO7T3-ENX0fzytPmJWmtoA@mail.gmail.com>
2020-05-03 17:06 ` Jiri Olsa
2020-05-03 17:31 ` Ian Rogers
2020-05-03 22:16 ` Jiri Olsa
2020-05-07 8:44 ` [PATCH v4 00/12] perf metric fixes and test Jiri Olsa
2020-05-07 16:00 ` Arnaldo Carvalho de Melo
2020-05-11 15:32 ` Arnaldo Carvalho de Melo
2020-05-11 16:12 ` Ian Rogers
2020-05-13 6:32 ` Ian Rogers
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