[PATCH v1] perf test code-reading: Fix duplicate kernel maps and machine leak

From: Ian Rogers

Date: Mon Sep 28 2026 - 03:58:13 EST


In do_test_code_reading(), machine__new_host(&host_env) already calls
machine__create_kernel_maps(machine). Calling
machine__create_kernel_maps(machine) a second time immediately
afterwards duplicates all kernel module maps in machine->kmaps, causing
dso__load_kcore()'s module validation (do_validate_kcore_modules()) to
fail and fall back to /proc/kallsyms.

Furthermore, when try_kcore is true and !have_kcore, returning
TEST_CODE_READING_NO_KCORE directly bypasses out_err, leaking the entire
struct machine, its kernel/module maps and DSOs, all kallsyms symbols,
and host_env.

Remove the redundant machine__create_kernel_maps() call, check for
!machine after machine__new_host(), and jump to out_err when returning
TEST_CODE_READING_NO_KCORE.

Fixes: 0fd4008ed755 ("perf test: Use machine__new_host in mmap thread code reading test")
Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/tests/code-reading.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index f0e8ea8754ef..c50b526f44fb 100644
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -716,10 +716,8 @@ static int do_test_code_reading(bool try_kcore)

perf_env__init(&host_env);
machine = machine__new_host(&host_env);
-
- ret = machine__create_kernel_maps(machine);
- if (ret < 0) {
- pr_debug("machine__create_kernel_maps failed\n");
+ if (!machine) {
+ pr_debug("machine__new_host failed\n");
goto out_err;
}

@@ -739,8 +737,10 @@ static int do_test_code_reading(bool try_kcore)
have_kcore = dso__is_kcore(dso);

/* 2nd time through we just try kcore */
- if (try_kcore && !have_kcore)
- return TEST_CODE_READING_NO_KCORE;
+ if (try_kcore && !have_kcore) {
+ err = TEST_CODE_READING_NO_KCORE;
+ goto out_err;
+ }

/* No point getting kernel events if there is no kernel object */
if (!have_vmlinux && !have_kcore)
--
2.56.0.rc1.315.gc6ed9934b7-goog