[PATCH 5.8 170/232] perf tools: Fix term parsing for raw syntax

From: Greg Kroah-Hartman
Date: Thu Aug 20 2020 - 05:34:58 EST


From: Jiri Olsa <jolsa@xxxxxxxxxx>

[ Upstream commit 4929e95a1400e45b4b5a87fd3ce10273444187d4 ]

Jin Yao reported issue with possible conflict between raw events and
term values in pmu event syntax.

Currently following syntax is resolved as raw event with 0xead value:

uncore_imc_free_running/read/

instead of using 'read' term from uncore_imc_free_running pmu, because
'read' is correct raw event syntax with 0xead value.

To solve this issue we do following:

- check existing terms during rXXXX syntax processing
and make them priority in case of conflict

- allow pmu/r0x1234/ syntax to be able to specify conflicting
raw event (implemented in previous patch)

Also add automated tests for this and perf_pmu__parse_cleanup call to
parse_events_terms, so the test gets properly cleaned up.

Fixes: 3a6c51e4d66c ("perf parser: Add support to specify rXXX event with pmu")
Reported-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
Acked-by: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Michael Petlan <mpetlan@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Richter <tmricht@xxxxxxxxxxxxx>
Link: http://lore.kernel.org/lkml/20200726075244.1191481-2-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/perf/tests/parse-events.c | 37 ++++++++++++++++++++++++++++++++-
tools/perf/util/parse-events.c | 28 +++++++++++++++++++++++++
tools/perf/util/parse-events.h | 2 ++
tools/perf/util/parse-events.l | 19 ++++++++++-------
4 files changed, 77 insertions(+), 9 deletions(-)

diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index 895188b63f963..6a2ec6ec0d0ef 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -631,6 +631,34 @@ static int test__checkterms_simple(struct list_head *terms)
TEST_ASSERT_VAL("wrong val", term->val.num == 1);
TEST_ASSERT_VAL("wrong config", !strcmp(term->config, "umask"));

+ /*
+ * read
+ *
+ * The perf_pmu__test_parse_init injects 'read' term into
+ * perf_pmu_events_list, so 'read' is evaluated as read term
+ * and not as raw event with 'ead' hex value.
+ */
+ term = list_entry(term->list.next, struct parse_events_term, list);
+ TEST_ASSERT_VAL("wrong type term",
+ term->type_term == PARSE_EVENTS__TERM_TYPE_USER);
+ TEST_ASSERT_VAL("wrong type val",
+ term->type_val == PARSE_EVENTS__TERM_TYPE_NUM);
+ TEST_ASSERT_VAL("wrong val", term->val.num == 1);
+ TEST_ASSERT_VAL("wrong config", !strcmp(term->config, "read"));
+
+ /*
+ * r0xead
+ *
+ * To be still able to pass 'ead' value with 'r' syntax,
+ * we added support to parse 'r0xHEX' event.
+ */
+ term = list_entry(term->list.next, struct parse_events_term, list);
+ TEST_ASSERT_VAL("wrong type term",
+ term->type_term == PARSE_EVENTS__TERM_TYPE_CONFIG);
+ TEST_ASSERT_VAL("wrong type val",
+ term->type_val == PARSE_EVENTS__TERM_TYPE_NUM);
+ TEST_ASSERT_VAL("wrong val", term->val.num == 0xead);
+ TEST_ASSERT_VAL("wrong config", !term->config);
return 0;
}

@@ -1776,7 +1804,7 @@ struct terms_test {

static struct terms_test test__terms[] = {
[0] = {
- .str = "config=10,config1,config2=3,umask=1",
+ .str = "config=10,config1,config2=3,umask=1,read,r0xead",
.check = test__checkterms_simple,
},
};
@@ -1836,6 +1864,13 @@ static int test_term(struct terms_test *t)

INIT_LIST_HEAD(&terms);

+ /*
+ * The perf_pmu__test_parse_init prepares perf_pmu_events_list
+ * which gets freed in parse_events_terms.
+ */
+ if (perf_pmu__test_parse_init())
+ return -1;
+
ret = parse_events_terms(&terms, t->str);
if (ret) {
pr_debug("failed to parse terms '%s', err %d\n",
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 3decbb203846a..4476de0e678aa 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -2017,6 +2017,32 @@ static void perf_pmu__parse_init(void)
perf_pmu__parse_cleanup();
}

+/*
+ * This function injects special term in
+ * perf_pmu_events_list so the test code
+ * can check on this functionality.
+ */
+int perf_pmu__test_parse_init(void)
+{
+ struct perf_pmu_event_symbol *list;
+
+ list = malloc(sizeof(*list) * 1);
+ if (!list)
+ return -ENOMEM;
+
+ list->type = PMU_EVENT_SYMBOL;
+ list->symbol = strdup("read");
+
+ if (!list->symbol) {
+ free(list);
+ return -ENOMEM;
+ }
+
+ perf_pmu_events_list = list;
+ perf_pmu_events_list_num = 1;
+ return 0;
+}
+
enum perf_pmu_event_symbol_type
perf_pmu__parse_check(const char *name)
{
@@ -2078,6 +2104,8 @@ int parse_events_terms(struct list_head *terms, const char *str)
int ret;

ret = parse_events__scanner(str, &parse_state);
+ perf_pmu__parse_cleanup();
+
if (!ret) {
list_splice(parse_state.terms, terms);
zfree(&parse_state.terms);
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 1fe23a2f9b36e..0b8cdb7270f04 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -253,4 +253,6 @@ static inline bool is_sdt_event(char *str __maybe_unused)
}
#endif /* HAVE_LIBELF_SUPPORT */

+int perf_pmu__test_parse_init(void);
+
#endif /* __PERF_PARSE_EVENTS_H */
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 002802e17059e..7332d16cb4fc7 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -41,14 +41,6 @@ static int value(yyscan_t scanner, int base)
return __value(yylval, text, base, PE_VALUE);
}

-static int raw(yyscan_t scanner)
-{
- YYSTYPE *yylval = parse_events_get_lval(scanner);
- char *text = parse_events_get_text(scanner);
-
- return __value(yylval, text + 1, 16, PE_RAW);
-}
-
static int str(yyscan_t scanner, int token)
{
YYSTYPE *yylval = parse_events_get_lval(scanner);
@@ -72,6 +64,17 @@ static int str(yyscan_t scanner, int token)
return token;
}

+static int raw(yyscan_t scanner)
+{
+ YYSTYPE *yylval = parse_events_get_lval(scanner);
+ char *text = parse_events_get_text(scanner);
+
+ if (perf_pmu__parse_check(text) == PMU_EVENT_SYMBOL)
+ return str(scanner, PE_NAME);
+
+ return __value(yylval, text + 1, 16, PE_RAW);
+}
+
static bool isbpf_suffix(char *text)
{
int len = strlen(text);
--
2.25.1