The format_alias() function in util/pmu.c has a check to
detect whether the event has parameterized field ( =? ).
The string alias->terms contains the event and if the event
has user configurable parameter, there will be presence of
sub string "=?" in the alias->terms.

Snippet of code:

 /* Paramemterized events have the parameters shown. */
       if (strstr(alias->terms, "=?")) {
               /* No parameters. */
               snprintf(buf, len, "%.*s/%s/", (int)pmu_name_len, pmu->name, 
alias->name);

if "strstr" contains the substring, it returns a pointer
and hence enters the above check which is not the expected
check. And hence "perf list" doesn't have the parameterized
fields in the result.

Fix this check to use:

if (!strstr(alias->terms, "=?")) {

With this change, perf list shows the events correctly with
the strings showing parameters.

Other changes in this patch:
- Replace snprintf with scnprintf in buffer offset calculations to
ensure the 'used' count will not exceed the "len"
- If a parameterized event uses a built-in perf keyword for its
parameter name (eg, config=?), the lexer parses it as a predefined
term token, which sets term->config to NULL. Add check to use
parse_events__term_type_str() if term->config is NULL

Signed-off-by: Athira Rajeev <[email protected]>
---
Changelog:
v2 -> v3:
After review from Sashiko, added below changes:
- Corrected commit message to say "strstr" which was previously
added as "str_ends_with".
- Updated snprintf with scnprintf in perf_pmu__for_each_event()
as well.
v1 -> v2:
After review from Sashiko, added below changes:
- Replace snprintf with scnprintf in buffer offset calculations to
ensure the 'used' count will not exceed the "len"
- If a parameterized event uses a built-in perf keyword for its
parameter name (eg, config=?), the lexer parses it as a predefined
term token, which sets term->config to NULL. Add check to use
parse_events__term_type_str() if term->config is NULL

 tools/perf/util/pmu.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 23337d2fa281..ca0ceb0623ca 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -2117,7 +2117,7 @@ static char *format_alias(char *buf, int len, const 
struct perf_pmu *pmu,
                                                   skip_duplicate_pmus);
 
        /* Paramemterized events have the parameters shown. */
-       if (strstr(alias->terms, "=?")) {
+       if (!strstr(alias->terms, "=?")) {
                /* No parameters. */
                snprintf(buf, len, "%.*s/%s/", (int)pmu_name_len, pmu->name, 
alias->name);
                return buf;
@@ -2129,15 +2129,19 @@ static char *format_alias(char *buf, int len, const 
struct perf_pmu *pmu,
                pr_err("Failure to parse '%s' terms '%s': %d\n",
                        alias->name, alias->terms, ret);
                parse_events_terms__exit(&terms);
-               snprintf(buf, len, "%.*s/%s/", (int)pmu_name_len, pmu->name, 
alias->name);
+               scnprintf(buf, len, "%.*s/%s/", (int)pmu_name_len, pmu->name, 
alias->name);
                return buf;
        }
-       used = snprintf(buf, len, "%.*s/%s", (int)pmu_name_len, pmu->name, 
alias->name);
+       used = scnprintf(buf, len, "%.*s/%s", (int)pmu_name_len, pmu->name, 
alias->name);
 
        list_for_each_entry(term, &terms.terms, list) {
+               const char *name = term->config;
+
+               if (!name)
+                       name = parse_events__term_type_str(term->type_term);
                if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR)
-                       used += snprintf(buf + used, sub_non_neg(len, used),
-                                       ",%s=%s", term->config,
+                       used += scnprintf(buf + used, sub_non_neg(len, used),
+                                       ",%s=%s", name,
                                        term->val.str);
        }
        parse_events_terms__exit(&terms);
@@ -2237,13 +2241,13 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool 
skip_duplicate_pmus,
                info.scale_unit = NULL;
                if (strlen(event->unit) || event->scale != 1.0) {
                        info.scale_unit = buf + buf_used;
-                       buf_used += snprintf(buf + buf_used, sizeof(buf) - 
buf_used,
+                       buf_used += scnprintf(buf + buf_used, sizeof(buf) - 
buf_used,
                                        "%G%s", event->scale, event->unit) + 1;
                }
                info.desc = event->desc;
                info.long_desc = event->long_desc;
                info.encoding_desc = buf + buf_used;
-               buf_used += snprintf(buf + buf_used, sizeof(buf) - buf_used,
+               buf_used += scnprintf(buf + buf_used, sizeof(buf) - buf_used,
                                "%.*s/%s/", (int)pmu_name_len, info.pmu_name, 
event->terms) + 1;
                info.str = event->terms;
                info.topic = event->topic;
@@ -2254,7 +2258,7 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool 
skip_duplicate_pmus,
        }
        if (pmu->selectable) {
                info.name = buf;
-               snprintf(buf, sizeof(buf), "%s//", pmu->name);
+               scnprintf(buf, sizeof(buf), "%s//", pmu->name);
                info.alias = NULL;
                info.scale_unit = NULL;
                info.desc = NULL;
-- 
2.47.3


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