6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jordan Rome <linux@xxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxx>
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Acked-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20231112023010.144675-1-linux@xxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -334,6 +334,8 @@ 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
