[PATCH 3/4] perf tools: Use const for variables receiving str{str,r?chr}() returns

[Arnaldo Carvalho de Melo]

Newer glibc versions return const char for str{str,chr}() where the
haystack/s is const so to avoid warnings like these on fedora 44 change
some variables to const:

  36     8.17 fedora:44                     : FAIL gcc version 15.2.1 20251111 (Red Hat 15.2.1-4) (GCC)
    libbpf.c: In function 'kallsyms_cb':
    libbpf.c:8489:13: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
     8489 |         res = strstr(sym_name, ".llvm.");

Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/jvmti/libjvmti.c     | 2 +-
 tools/perf/tests/parse-events.c | 4 ++--
 tools/perf/util/evlist.c        | 3 ++-
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/tools/perf/jvmti/libjvmti.c b/tools/perf/jvmti/libjvmti.c
index 82514e6532b8c3af..87bfd4781003a331 100644
--- a/tools/perf/jvmti/libjvmti.c
+++ b/tools/perf/jvmti/libjvmti.c
@@ -142,7 +142,7 @@ copy_class_filename(const char * class_sign, const char * file_name, char * resu
 	*/
 	if (*class_sign == 'L') {
 		size_t j, i = 0;
-		char *p = strrchr(class_sign, '/');
+		const char *p = strrchr(class_sign, '/');
 		if (p) {
 			/* drop the 'L' prefix and copy up to the final '/' */
 			for (i = 0; i < (size_t)(p - class_sign); i++)
diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index 128d21dc389f869b..2bd6229721145e42 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -2609,8 +2609,8 @@ static int test_events(const struct evlist_test *events, int cnt)
 	for (int i = 0; i < cnt; i++) {
 		struct evlist_test e = events[i];
 		int test_ret;
-		const char *pos = e.name;
-		char buf[1024], *buf_pos = buf, *end;
+		const char *pos = e.name, *end;
+		char buf[1024], *buf_pos = buf;
 
 		while ((end = strstr(pos, "default_core"))) {
 			size_t len = end - pos;
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 03674d2cbd015e4f..64951962854104a5 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1945,7 +1945,8 @@ static int evlist__parse_control_fifo(const char *str, int *ctl_fd, int *ctl_fd_
 
 int evlist__parse_control(const char *str, int *ctl_fd, int *ctl_fd_ack, bool *ctl_fd_close)
 {
-	char *comma = NULL, *endptr = NULL;
+	const char *comma = NULL;
+	char *endptr = NULL;
 
 	*ctl_fd_close = false;
 
-- 
2.52.0