[PATCH v8 20/58] perf python: Add syscall name/id to convert syscall number and name

Ian Rogers
2026-04-28T07:21:02Z

Use perf's syscalltbl support to convert syscall number to name
assuming the number is for the host machine. This avoids python
libaudit support as tools/perf/scripts/python/syscall-counts.py
requires.

Assisted-by: Gemini:gemini-3.1-pro-preview
Signed-off-by: Ian Rogers <irogers@google.com>
---
v2:

1. Guarded with HAVE_LIBTRACEEVENT : Wrapped the syscall functions and
their entries in perf__methods with #ifdef HAVE_LIBTRACEEVENT to
avoid potential linker errors if CONFIG_TRACE is disabled.

2. Changed Exception Type: Updated pyrf__syscall_id to raise a
ValueError instead of a TypeError when a syscall is not found.

3. Fixed Typo: Corrected "name number" to "name" in the docstring for
syscall_id.

v6:
- Added optional keyword-only `elf_machine` argument to `syscall_name`
and `syscall_id`.

v7:
- Made syscalltbl.o unconditional in Build to fix undefined symbol
when building without libtraceevent.
---
tools/perf/util/Build | 2 +-
tools/perf/util/python.c | 48 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 70cc91d00804..fd55d02dd433 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -75,7 +75,7 @@ perf-util-y += sample.o
perf-util-y += sample-raw.o
perf-util-y += s390-sample-raw.o
perf-util-y += amd-sample-raw.o
-perf-util-$(CONFIG_TRACE) += syscalltbl.o
+perf-util-y += syscalltbl.o
perf-util-y += ordered-events.o
perf-util-y += namespaces.o
perf-util-y += comm.o
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index c947abf8affe..69d443c504d3 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -16,6 +16,7 @@
#include "data.h"
#include "debug.h"
#include "dso.h"
+#include "dwarf-regs.h"
#include "event.h"
#include "branch.h"
#include "evlist.h"
@@ -33,6 +34,7 @@
#include "srcline.h"
#include "strbuf.h"
#include "symbol.h"
+#include "syscalltbl.h"
#include "thread.h"
#include "thread_map.h"
#include "tool.h"
@@ -3785,6 +3787,40 @@ static int pyrf_session__setup_types(void)
return PyType_Ready(&pyrf_session__type);
}

+static PyObject *pyrf__syscall_name(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+ const char *name;
+ int id;
+ int elf_machine = EM_HOST;
+ static char * const kwlist[] = { "id", "elf_machine", NULL };
+
+ if (!PyArg_ParseTupleAndKeywords(args, kwargs, "i|$i", kwlist, &id, &elf_machine))
+ return NULL;
+
+ name = syscalltbl__name(elf_machine, id);
+ if (!name)
+ Py_RETURN_NONE;
+ return PyUnicode_FromString(name);
+}
+
+static PyObject *pyrf__syscall_id(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+ const char *name;
+ int id;
+ int elf_machine = EM_HOST;
+ static char * const kwlist[] = { "name", "elf_machine", NULL };
+
+ if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s|$i", kwlist, &name, &elf_machine))
+ return NULL;
+
+ id = syscalltbl__id(elf_machine, name);
+ if (id < 0) {
+ PyErr_Format(PyExc_ValueError, "Failed to find syscall %s", name);
+ return NULL;
+ }
+ return PyLong_FromLong(id);
+}
+
static PyMethodDef perf__methods[] = {
{
.ml_name = "metrics",
@@ -3818,6 +3854,18 @@ static PyMethodDef perf__methods[] = {
.ml_flags = METH_NOARGS,
.ml_doc = PyDoc_STR("Returns a sequence of pmus.")
},
+ {
+ .ml_name = "syscall_name",
+ .ml_meth = (PyCFunction) pyrf__syscall_name,
+ .ml_flags = METH_VARARGS | METH_KEYWORDS,
+ .ml_doc = PyDoc_STR("Turns a syscall number to a string.")
+ },
+ {
+ .ml_name = "syscall_id",
+ .ml_meth = (PyCFunction) pyrf__syscall_id,
+ .ml_flags = METH_VARARGS | METH_KEYWORDS,
+ .ml_doc = PyDoc_STR("Turns a syscall name to a number.")
+ },
{ .ml_name = NULL, }
};

--
2.54.0.545.g6539524ca2-goog