From: Ian Rogers <irogers@google.com>
To: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>,
James Clark <james.clark@arm.com>,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
bpf@vger.kernel.org, Atish Patra <atishp@rivosinc.com>,
linux-riscv@lists.infradead.org,
Beeman Strong <beeman@rivosinc.com>
Subject: Re: [PATCH v2 11/16] perf parse-events: Improve error message for bad numbers
Date: Thu, 18 Apr 2024 14:07:31 -0700 [thread overview]
Message-ID: <CAP-5=fXkn-nFTqGEqBYt6NUvoXU7OyLJeSCnWdD3taLHyK-xtQ@mail.gmail.com> (raw)
In-Reply-To: <ac8835f8-0ea5-4f28-941c-aa43f0da92fd@linux.intel.com>
On Thu, Apr 18, 2024 at 1:27 PM Liang, Kan <kan.liang@linux.intel.com> wrote:
>
>
>
> On 2024-04-16 2:15 a.m., Ian Rogers wrote:
> > Use the error handler from the parse_state to give a more informative
> > error message.
> >
> > Before:
> > ```
> > $ perf stat -e 'cycles/period=99999999999999999999/' true
> > event syntax error: 'cycles/period=99999999999999999999/'
> > \___ parser error
> > Run 'perf list' for a list of valid events
> >
> > Usage: perf stat [<options>] [<command>]
> >
> > -e, --event <event> event selector. use 'perf list' to list available events
> > ```
> >
> > After:
> > ```
> > $ perf stat -e 'cycles/period=99999999999999999999/' true
> > event syntax error: 'cycles/period=99999999999999999999/'
> > \___ parser error
> >
> > event syntax error: '..les/period=99999999999999999999/'
> > \___ Bad base 10 number "99999999999999999999"
>
>
> It seems the patch only works for decimal?
>
> ./perf stat -e 'cycles/period=0xaaaaaaaaaaaaaaaaaaaaaa/' true
> event syntax error: '..les/period=0xaaaaaaaaaaaaaaaaaaaaaa/'
> \___ parser error
> Run 'perf list' for a list of valid events
>
> Usage: perf stat [<options>] [<command>]
>
> -e, --event <event> event selector. use 'perf list' to list
> available events
>
> Thanks,
> Kan
Right, for hexadecimal we say the number of digits is at most 16, so
when you exceed this the token is no longer recognized. It just
becomes input that can't be parsed, hence parser error. Doing this
means we can simplify other strtoull checks, but I agree having a
better error message for hexadecimal would be good. Let's do it as
follow up.
Thanks,
Ian
> > Run 'perf list' for a list of valid events
> >
> > Usage: perf stat [<options>] [<command>]
> >
> > -e, --event <event> event selector. use 'perf list' to list available events
> > ```
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > ---
> > tools/perf/util/parse-events.l | 40 ++++++++++++++++++++--------------
> > 1 file changed, 24 insertions(+), 16 deletions(-)
> >
> > diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
> > index 6fe37003ab7b..0cd68c9f0d4f 100644
> > --- a/tools/perf/util/parse-events.l
> > +++ b/tools/perf/util/parse-events.l
> > @@ -18,26 +18,34 @@
> >
> > char *parse_events_get_text(yyscan_t yyscanner);
> > YYSTYPE *parse_events_get_lval(yyscan_t yyscanner);
> > +int parse_events_get_column(yyscan_t yyscanner);
> > +int parse_events_get_leng(yyscan_t yyscanner);
> >
> > -static int __value(YYSTYPE *yylval, char *str, int base, int token)
> > +static int get_column(yyscan_t scanner)
> > {
> > - u64 num;
> > -
> > - errno = 0;
> > - num = strtoull(str, NULL, base);
> > - if (errno)
> > - return PE_ERROR;
> > -
> > - yylval->num = num;
> > - return token;
> > + return parse_events_get_column(scanner) - parse_events_get_leng(scanner);
> > }
> >
> > -static int value(yyscan_t scanner, int base)
> > +static int value(struct parse_events_state *parse_state, yyscan_t scanner, int base)
> > {
> > YYSTYPE *yylval = parse_events_get_lval(scanner);
> > char *text = parse_events_get_text(scanner);
> > + u64 num;
> >
> > - return __value(yylval, text, base, PE_VALUE);
> > + errno = 0;
> > + num = strtoull(text, NULL, base);
> > + if (errno) {
> > + struct parse_events_error *error = parse_state->error;
> > + char *help = NULL;
> > +
> > + if (asprintf(&help, "Bad base %d number \"%s\"", base, text) > 0)
> > + parse_events_error__handle(error, get_column(scanner), help , NULL);
> > +
> > + return PE_ERROR;
> > + }
> > +
> > + yylval->num = num;
> > + return PE_VALUE;
> > }
> >
> > static int str(yyscan_t scanner, int token)
> > @@ -283,8 +291,8 @@ r0x{num_raw_hex} { return str(yyscanner, PE_RAW); }
> > */
> > "/"/{digit} { return PE_BP_SLASH; }
> > "/"/{non_digit} { BEGIN(config); return '/'; }
> > -{num_dec} { return value(yyscanner, 10); }
> > -{num_hex} { return value(yyscanner, 16); }
> > +{num_dec} { return value(_parse_state, yyscanner, 10); }
> > +{num_hex} { return value(_parse_state, yyscanner, 16); }
> > /*
> > * We need to separate 'mem:' scanner part, in order to get specific
> > * modifier bits parsed out. Otherwise we would need to handle PE_NAME
> > @@ -330,8 +338,8 @@ cgroup-switches { return sym(yyscanner, PERF_COUNT_SW_CGROUP_SWITCHES); }
> > {lc_type}-{lc_op_result}-{lc_op_result} { return str(yyscanner, PE_LEGACY_CACHE); }
> > mem: { BEGIN(mem); return PE_PREFIX_MEM; }
> > r{num_raw_hex} { return str(yyscanner, PE_RAW); }
> > -{num_dec} { return value(yyscanner, 10); }
> > -{num_hex} { return value(yyscanner, 16); }
> > +{num_dec} { return value(_parse_state, yyscanner, 10); }
> > +{num_hex} { return value(_parse_state, yyscanner, 16); }
> >
> > {modifier_event} { return str(yyscanner, PE_MODIFIER_EVENT); }
> > {name} { return str(yyscanner, PE_NAME); }
next prev parent reply other threads:[~2024-04-18 21:07 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-16 6:15 [PATCH v2 00/16] Consistently prefer sysfs/json events Ian Rogers
2024-04-16 6:15 ` [PATCH v2 01/16] perf parse-events: Factor out '<event_or_pmu>/.../' parsing Ian Rogers
2024-04-16 6:15 ` [PATCH v2 02/16] perf parse-events: Directly pass PMU to parse_events_add_pmu Ian Rogers
2024-04-16 6:15 ` [PATCH v2 03/16] perf parse-events: Avoid copying an empty list Ian Rogers
2024-04-16 6:15 ` [PATCH v2 04/16] perf pmu: Refactor perf_pmu__match Ian Rogers
2024-04-16 6:15 ` [PATCH v2 05/16] perf tests parse-events: Use branches rather than cache-references Ian Rogers
2024-04-16 6:15 ` [PATCH v2 06/16] perf parse-events: Legacy cache names on all PMUs and lower priority Ian Rogers
2024-04-16 6:15 ` [PATCH v2 07/16] perf parse-events: Handle PE_TERM_HW in name_or_raw Ian Rogers
2024-04-16 6:15 ` [PATCH v2 08/16] perf parse-events: Constify parse_events_add_numeric Ian Rogers
2024-04-16 6:15 ` [PATCH v2 09/16] perf parse-events: Prefer sysfs/json hardware events over legacy Ian Rogers
2024-04-16 6:15 ` [PATCH v2 10/16] perf parse-events: Inline parse_events_update_lists Ian Rogers
2024-04-16 6:15 ` [PATCH v2 11/16] perf parse-events: Improve error message for bad numbers Ian Rogers
2024-04-18 20:27 ` Liang, Kan
2024-04-18 21:07 ` Ian Rogers [this message]
2024-04-19 13:29 ` Liang, Kan
2024-04-27 1:35 ` Arnaldo Carvalho de Melo
2024-04-27 1:36 ` Arnaldo Carvalho de Melo
2024-04-27 22:05 ` Ian Rogers
2024-04-16 6:15 ` [PATCH v2 12/16] perf parse-events: Inline parse_events_evlist_error Ian Rogers
2024-04-16 6:15 ` [PATCH v2 13/16] perf parse-events: Improvements to modifier parsing Ian Rogers
2024-04-18 20:32 ` Liang, Kan
2024-04-19 6:22 ` Ian Rogers
2024-04-19 13:20 ` Liang, Kan
2024-04-24 15:18 ` Ian Rogers
2024-04-24 15:30 ` Liang, Kan
2024-04-16 6:15 ` [PATCH v2 14/16] perf parse-event: Constify event_symbol arrays Ian Rogers
2024-04-16 6:15 ` [PATCH v2 15/16] perf parse-events: Minor grouping tidy up Ian Rogers
2024-04-16 6:15 ` [PATCH v2 16/16] perf parse-events: Tidy the setting of the default event name Ian Rogers
2024-04-24 0:28 ` [PATCH v2 00/16] Consistently prefer sysfs/json events Atish Kumar Patra
2024-04-24 15:14 ` Ian Rogers
2024-04-24 15:34 ` Liang, Kan
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