[PATCH bpf-next] selftests/bpf: Run the cpumask map insert tests only for the test task

[PATCH bpf-next] selftests/bpf: Run the cpumask map insert tests only for the test task

[Qiliang Yuan]

verify_success() attaches each cpumask test program to task_newtask,
forks a single child, and expects err to be 0 afterwards. Most programs
return right away for other tasks than the test one.

test_insert_leave and test_insert_remove_release don't, and insert a
cpumask into the single entry of __cpumask_map for every task created
in the system while they are attached. test_insert_leave leaves its
cpumask in the map, so a second task created, for instance by a test
running in parallel, fails to insert one and sets err to 3. Two tasks
created at the same time can do the same to test_insert_remove_release.

Return early for other tasks than the test one in both programs, as the
other programs do.

Fixes: 7b6abcfa15cd ("selftests/bpf: Add selftest suite for cpumask kfuncs")
Signed-off-by: Qiliang Yuan <odys.yuan@gmail.com>
---
 tools/testing/selftests/bpf/progs/cpumask_success.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/testing/selftests/bpf/progs/cpumask_success.c b/tools/testing/selftests/bpf/progs/cpumask_success.c
index 36f77b9732d46..ddaba4318c574 100644
--- a/tools/testing/selftests/bpf/progs/cpumask_success.c
+++ b/tools/testing/selftests/bpf/progs/cpumask_success.c
@@ -460,6 +460,9 @@ int BPF_PROG(test_insert_leave, struct task_struct *task, u64 clone_flags)
 {
 	struct bpf_cpumask *cpumask;
 
+	if (!is_test_task())
+		return 0;
+
 	cpumask = create_cpumask();
 	if (!cpumask)
 		return 0;
@@ -476,6 +479,9 @@ int BPF_PROG(test_insert_remove_release, struct task_struct *task, u64 clone_fla
 	struct bpf_cpumask *cpumask;
 	struct __cpumask_map_value *v;
 
+	if (!is_test_task())
+		return 0;
+
 	cpumask = create_cpumask();
 	if (!cpumask)
 		return 0;

---
base-commit: e1d84a37cba984388988d2f1ddc84561413f0db2
change-id: 20261009-selftests-bpf-cpumask-insert-filter-6f98ea387301

Best regards,
-- 
Qiliang Yuan <odys.yuan@gmail.com>

Re: [PATCH bpf-next] selftests/bpf: Run the cpumask map insert tests only for the test task

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to bpf/bpf-next.git (master)
by Kumar Kartikeya Dwivedi <memxor@gmail.com>:

On Fri, 09 Oct 2026 09:49:32 +0800 you wrote:
> verify_success() attaches each cpumask test program to task_newtask,
> forks a single child, and expects err to be 0 afterwards. Most programs
> return right away for other tasks than the test one.
> 
> test_insert_leave and test_insert_remove_release don't, and insert a
> cpumask into the single entry of __cpumask_map for every task created
> in the system while they are attached. test_insert_leave leaves its
> cpumask in the map, so a second task created, for instance by a test
> running in parallel, fails to insert one and sets err to 3. Two tasks
> created at the same time can do the same to test_insert_remove_release.
> 
> [...]

Here is the summary with links:
  - [bpf-next] selftests/bpf: Run the cpumask map insert tests only for the test task
    https://git.kernel.org/bpf/bpf-next/c/e2c978ad415c

You are awesome, thank you!
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