perf python: Correctly throw IndexError

Correctly throw IndexError for out-of-bound accesses to evlist:

  Python 3.11.9 (main, Jun 19 2024, 00:38:48) [GCC 13.2.0] on linux
  Type "help", "copyright", "credits" or "license" for more information.
  >>> import sys
  >>> sys.path.insert(0, '/tmp/perf/python')
  >>> import perf
  >>> x=perf.parse_events('cycles')
  >>> print(x)
  evlist([cycles])
  >>> x[2]
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
  IndexError: Index out of range

Signed-off-by: Ian Rogers <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Colin Ian King <[email protected]>
Cc: Dapeng Mi <[email protected]>
Cc: Howard Chu <[email protected]>
Cc: Ilya Leoshkevich <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Michael Petlan <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Richter <[email protected]>
Cc: Veronika Molnarova <[email protected]>
Cc: Weilin Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 3 insertions, 1 deletions

diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index 893aa4185c03..b4bc57859f73 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -1071,8 +1071,10 @@ static PyObject *pyrf_evlist__item(PyObject *obj, Py_ssize_t i)
 	struct pyrf_evlist *pevlist = (void *)obj;
 	struct evsel *pos;
 
-	if (i >= pevlist->evlist.core.nr_entries)
+	if (i >= pevlist->evlist.core.nr_entries) {
+		PyErr_SetString(PyExc_IndexError, "Index out of range");
 		return NULL;
+	}
 
 	evlist__for_each_entry(&pevlist->evlist, pos) {
 		if (i-- == 0)