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perf parse-events: Improvements to modifier parsing

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Use a struct/bitmap rather than a copied string from lexer.

In lexer give improved error message when too many precise flags are
given or repeated modifiers.

Before:

  $ perf stat -e 'cycles:kuk' true
  event syntax error: 'cycles:kuk'
                              \___ Bad modifier
  ...
  $ perf stat -e 'cycles:pppp' true
  event syntax error: 'cycles:pppp'
                              \___ Bad modifier
  ...
  $ perf stat -e '{instructions:p,cycles:pp}:pp' -a true
  event syntax error: '..cycles:pp}:pp'
                                    \___ Bad modifier
  ...

After:

  $ perf stat -e 'cycles:kuk' true
  event syntax error: 'cycles:kuk'
                                \___ Duplicate modifier 'k' (kernel)
  ...
  $ perf stat -e 'cycles:pppp' true
  event syntax error: 'cycles:pppp'
                                 \___ Maximum precise value is 3
  ...
  $ perf stat -e '{instructions:p,cycles:pp}:pp' true
  event syntax error: '..cycles:pp}:pp'
                                    \___ Maximum combined precise value is 3, adding precision to "cycles:pp"
  ...

Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Beeman Strong <beeman@rivosinc.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240416061533.921723-14-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Ian Rogers
2024-04-15 23:15:29 -07:00
committed by Arnaldo Carvalho de Melo
parent e18601d80c
commit e30a7912f4
4 changed files with 196 additions and 184 deletions
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75
tools/perf/util/parse-events.l
View File

@@ -142,6 +142,77 @@ static int hw(yyscan_t scanner, int config)
return PE_TERM_HW;
}
static void modifiers_error(struct parse_events_state *parse_state, yyscan_t scanner,
int pos, char mod_char, const char *mod_name)
{
struct parse_events_error *error = parse_state->error;
char *help = NULL;
if (asprintf(&help, "Duplicate modifier '%c' (%s)", mod_char, mod_name) > 0)
parse_events_error__handle(error, get_column(scanner) + pos, help , NULL);
}
static int modifiers(struct parse_events_state *parse_state, yyscan_t scanner)
{
YYSTYPE *yylval = parse_events_get_lval(scanner);
char *text = parse_events_get_text(scanner);
struct parse_events_modifier mod = { .precise = 0, };
for (size_t i = 0, n = strlen(text); i < n; i++) {
#define CASE(c, field) \
case c: \
if (mod.field) { \
modifiers_error(parse_state, scanner, i, c, #field); \
return PE_ERROR; \
} \
mod.field = true; \
break
switch (text[i]) {
CASE('u', user);
CASE('k', kernel);
CASE('h', hypervisor);
CASE('I', non_idle);
CASE('G', guest);
CASE('H', host);
case 'p':
mod.precise++;
/*
* precise ip:
*
* 0 - SAMPLE_IP can have arbitrary skid
* 1 - SAMPLE_IP must have constant skid
* 2 - SAMPLE_IP requested to have 0 skid
* 3 - SAMPLE_IP must have 0 skid
*
* See also PERF_RECORD_MISC_EXACT_IP
*/
if (mod.precise > 3) {
struct parse_events_error *error = parse_state->error;
char *help = strdup("Maximum precise value is 3");
if (help) {
parse_events_error__handle(error, get_column(scanner) + i,
help , NULL);
}
return PE_ERROR;
}
break;
CASE('P', precise_max);
CASE('S', sample_read);
CASE('D', pinned);
CASE('W', weak);
CASE('e', exclusive);
CASE('b', bpf);
default:
return PE_ERROR;
}
#undef CASE
}
yylval->mod = mod;
return PE_MODIFIER_EVENT;
}
#define YY_USER_ACTION \
do { \
yylloc->last_column = yylloc->first_column; \
@@ -174,7 +245,7 @@ drv_cfg_term [a-zA-Z0-9_\.]+(=[a-zA-Z0-9_*?\.:]+)?
* If you add a modifier you need to update check_modifier().
* Also, the letters in modifier_event must not be in modifier_bp.
*/
modifier_event [ukhpPGHSDIWeb]+
modifier_event [ukhpPGHSDIWeb]{1,15}
modifier_bp [rwx]{1,3}
lc_type (L1-dcache|l1-d|l1d|L1-data|L1-icache|l1-i|l1i|L1-instruction|LLC|L2|dTLB|d-tlb|Data-TLB|iTLB|i-tlb|Instruction-TLB|branch|branches|bpu|btb|bpc|node)
lc_op_result (load|loads|read|store|stores|write|prefetch|prefetches|speculative-read|speculative-load|refs|Reference|ops|access|misses|miss)
@@ -341,7 +412,7 @@ r{num_raw_hex} { return str(yyscanner, PE_RAW); }
{num_dec} { return value(_parse_state, yyscanner, 10); }
{num_hex} { return value(_parse_state, yyscanner, 16); }
{modifier_event} { return str(yyscanner, PE_MODIFIER_EVENT); }
{modifier_event} { return modifiers(_parse_state, yyscanner); }
{name} { return str(yyscanner, PE_NAME); }
{name_tag} { return str(yyscanner, PE_NAME); }
"/" { BEGIN(config); return '/'; }