5.15-stable review patch. If anyone has any objections, please let me know.
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From: Jordan Rome linux@jordanrome.com
commit 727a92d62fd6a382b4c5972008e45667e707b0e4 upstream.
This is a follow up to: commit b8e3a87a627b ("bpf: Add crosstask check to __bpf_get_stack").
This test ensures that the task iterator only gets a single user stack (for the current task).
Signed-off-by: Jordan Rome linux@jordanrome.com Signed-off-by: Andrii Nakryiko andrii@kernel.org Acked-by: Stanislav Fomichev sdf@google.com Link: https://lore.kernel.org/bpf/20231112023010.144675-1-linux@jordanrome.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/testing/selftests/bpf/prog_tests/bpf_iter.c | 2 ++ tools/testing/selftests/bpf/progs/bpf_iter_task_stack.c | 5 +++++ 2 files changed, 7 insertions(+)
--- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -150,6 +150,8 @@ static void test_task_stack(void) do_dummy_read(skel->progs.dump_task_stack); do_dummy_read(skel->progs.get_task_user_stacks);
+ ASSERT_EQ(skel->bss->num_user_stacks, 1, "num_user_stacks"); + bpf_iter_task_stack__destroy(skel); }
--- a/tools/testing/selftests/bpf/progs/bpf_iter_task_stack.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_task_stack.c @@ -35,6 +35,8 @@ int dump_task_stack(struct bpf_iter__tas return 0; }
+int num_user_stacks = 0; + SEC("iter/task") int get_task_user_stacks(struct bpf_iter__task *ctx) { @@ -51,6 +53,9 @@ int get_task_user_stacks(struct bpf_iter if (res <= 0) return 0;
+ /* Only one task, the current one, should succeed */ + ++num_user_stacks; + buf_sz += res;
/* If the verifier doesn't refine bpf_get_task_stack res, and instead