From 906bd22a44c7c381ae92996129b075ea7beba8f6 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Wed, 5 Jul 2023 20:17:30 +0530 Subject: [PATCH] selftests/bpf: Add selftest for check_stack_max_depth bug Use the bpf_timer_set_callback helper to mark timer_cb as an async callback, and put a direct call to timer_cb in the main subprog. As the check_stack_max_depth happens after the do_check pass, the order does not matter. Without the previous fix, the test passes successfully. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20230705144730.235802-3-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- .../bpf/prog_tests/async_stack_depth.c | 9 +++++ .../selftests/bpf/progs/async_stack_depth.c | 40 +++++++++++++++++++ 2 files changed, 49 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/async_stack_depth.c create mode 100644 tools/testing/selftests/bpf/progs/async_stack_depth.c diff --git a/tools/testing/selftests/bpf/prog_tests/async_stack_depth.c b/tools/testing/selftests/bpf/prog_tests/async_stack_depth.c new file mode 100644 index 000000000000..118abc29b236 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/async_stack_depth.c @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 +#include + +#include "async_stack_depth.skel.h" + +void test_async_stack_depth(void) +{ + RUN_TESTS(async_stack_depth); +} diff --git a/tools/testing/selftests/bpf/progs/async_stack_depth.c b/tools/testing/selftests/bpf/progs/async_stack_depth.c new file mode 100644 index 000000000000..477ba950bb43 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/async_stack_depth.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +#include "bpf_misc.h" + +struct hmap_elem { + struct bpf_timer timer; +}; + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 64); + __type(key, int); + __type(value, struct hmap_elem); +} hmap SEC(".maps"); + +__attribute__((noinline)) +static int timer_cb(void *map, int *key, struct bpf_timer *timer) +{ + volatile char buf[256] = {}; + return buf[69]; +} + +SEC("tc") +__failure __msg("combined stack size of 2 calls") +int prog(struct __sk_buff *ctx) +{ + struct hmap_elem *elem; + volatile char buf[256] = {}; + + elem = bpf_map_lookup_elem(&hmap, &(int){0}); + if (!elem) + return 0; + + timer_cb(NULL, NULL, NULL); + return bpf_timer_set_callback(&elem->timer, timer_cb) + buf[0]; +} + +char _license[] SEC("license") = "GPL";