Add selftests covering stack argument passing for both BPF-to-BPF subprog calls and kfunc calls with more than 5 arguments. All tests are guarded by __BPF_FEATURE_STACK_ARGUMENT and __TARGET_ARCH_x86. Signed-off-by: Yonghong Song --- .../selftests/bpf/prog_tests/stack_arg.c | 143 ++++++++++++++++++ tools/testing/selftests/bpf/progs/stack_arg.c | 111 ++++++++++++++ .../selftests/bpf/progs/stack_arg_kfunc.c | 59 ++++++++ .../selftests/bpf/test_kmods/bpf_testmod.c | 22 +++ .../bpf/test_kmods/bpf_testmod_kfunc.h | 7 + 5 files changed, 342 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/stack_arg.c create mode 100644 tools/testing/selftests/bpf/progs/stack_arg.c create mode 100644 tools/testing/selftests/bpf/progs/stack_arg_kfunc.c diff --git a/tools/testing/selftests/bpf/prog_tests/stack_arg.c b/tools/testing/selftests/bpf/prog_tests/stack_arg.c new file mode 100644 index 000000000000..86b8025f5541 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/stack_arg.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include "stack_arg.skel.h" +#include "stack_arg_kfunc.skel.h" + +static void test_nesting(void) +{ + struct stack_arg *skel; + int err, prog_fd; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .repeat = 1, + ); + + skel = stack_arg__open(); + if (!ASSERT_OK_PTR(skel, "open")) + return; + + if (!skel->rodata->has_stack_arg) { + test__skip(); + goto out; + } + + err = stack_arg__load(skel); + if (!ASSERT_OK(err, "load")) + goto out; + + skel->bss->a = 0; + skel->bss->b = 0; + skel->bss->c = 0; + skel->bss->d = 0; + skel->bss->e = 0; + skel->bss->f = 6; + skel->bss->g = 7; + skel->bss->i = 8; + + prog_fd = bpf_program__fd(skel->progs.test); + err = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(topts.retval, 29, "retval"); + +out: + stack_arg__destroy(skel); +} + +static void run_subtest(struct bpf_program *prog, int expected) +{ + int err, prog_fd; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .repeat = 1, + ); + + prog_fd = bpf_program__fd(prog); + err = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(topts.retval, expected, "retval"); +} + +static void test_global_many(void) +{ + struct stack_arg *skel; + + skel = stack_arg__open(); + if (!ASSERT_OK_PTR(skel, "open")) + return; + + if (!skel->rodata->has_stack_arg) { + test__skip(); + goto out; + } + + if (!ASSERT_OK(stack_arg__load(skel), "load")) + goto out; + + run_subtest(skel->progs.test_global_many_args, 36); + +out: + stack_arg__destroy(skel); +} + +static void test_async_cb_many(void) +{ + struct stack_arg *skel; + + skel = stack_arg__open(); + if (!ASSERT_OK_PTR(skel, "open")) + return; + + if (!skel->rodata->has_stack_arg) { + test__skip(); + goto out; + } + + if (!ASSERT_OK(stack_arg__load(skel), "load")) + goto out; + + run_subtest(skel->progs.test_async_cb_many_args, 0); + +out: + stack_arg__destroy(skel); +} + +static void test_kfunc(void) +{ + struct stack_arg_kfunc *skel; + + skel = stack_arg_kfunc__open(); + if (!ASSERT_OK_PTR(skel, "open")) + return; + + if (!skel->rodata->has_stack_arg) { + test__skip(); + goto out; + } + + if (!ASSERT_OK(stack_arg_kfunc__load(skel), "load")) + goto out; + + run_subtest(skel->progs.test_stack_arg_scalar, 36); + run_subtest(skel->progs.test_stack_arg_ptr, 45); + run_subtest(skel->progs.test_stack_arg_mix, 51); + +out: + stack_arg_kfunc__destroy(skel); +} + +void test_stack_arg(void) +{ + if (test__start_subtest("nesting")) + test_nesting(); + if (test__start_subtest("global_many_args")) + test_global_many(); + if (test__start_subtest("async_cb_many_args")) + test_async_cb_many(); + if (test__start_subtest("kfunc")) + test_kfunc(); +} diff --git a/tools/testing/selftests/bpf/progs/stack_arg.c b/tools/testing/selftests/bpf/progs/stack_arg.c new file mode 100644 index 000000000000..c139a699fc3c --- /dev/null +++ b/tools/testing/selftests/bpf/progs/stack_arg.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include + +#define CLOCK_MONOTONIC 1 + +long a, b, c, d, e, f, g, i; + +struct timer_elem { + struct bpf_timer timer; +}; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, int); + __type(value, struct timer_elem); +} timer_map SEC(".maps"); + +int timer_result; + +#if defined(__TARGET_ARCH_x86) && defined(__BPF_FEATURE_STACK_ARGUMENT) + +const volatile bool has_stack_arg = true; + +__noinline static long func_b(long a, long b, long c, long d, + long e, long f, long g, long h) +{ + return a + b + c + d + e + f + g + h; +} + +__noinline static long func_a(long a, long b, long c, long d, + long e, long f, long g, long h) +{ + return func_b(a + 1, b + 1, c + 1, d + 1, + e + 1, f + 1, g + 1, h + 1); +} + +SEC("tc") +int test(void) +{ + return func_a(a, b, c, d, e, f, g, i); +} + +__noinline static int static_func_many_args(int a, int b, int c, int d, + int e, int f, int g, int h) +{ + return a + b + c + d + e + f + g + h; +} + +__noinline int global_calls_many_args(int a, int b, int c) +{ + return static_func_many_args(a, b, c, 4, 5, 6, 7, 8); +} + +SEC("tc") +int test_global_many_args(void) +{ + return global_calls_many_args(1, 2, 3); +} + +static int timer_cb_many_args(void *map, int *key, struct bpf_timer *timer) +{ + timer_result = static_func_many_args(10, 20, 30, 40, 50, 60, 70, 80); + return 0; +} + +SEC("tc") +int test_async_cb_many_args(void) +{ + struct timer_elem *elem; + int key = 0; + + elem = bpf_map_lookup_elem(&timer_map, &key); + if (!elem) + return -1; + + bpf_timer_init(&elem->timer, &timer_map, CLOCK_MONOTONIC); + bpf_timer_set_callback(&elem->timer, timer_cb_many_args); + bpf_timer_start(&elem->timer, 1, 0); + return 0; +} + +#else + +const volatile bool has_stack_arg = false; + +SEC("tc") +int test(void) +{ + return 0; +} + +SEC("tc") +int test_global_many_args(void) +{ + return 0; +} + +SEC("tc") +int test_async_cb_many_args(void) +{ + return 0; +} + +#endif + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/stack_arg_kfunc.c b/tools/testing/selftests/bpf/progs/stack_arg_kfunc.c new file mode 100644 index 000000000000..a440e9b42a4a --- /dev/null +++ b/tools/testing/selftests/bpf/progs/stack_arg_kfunc.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include "../test_kmods/bpf_testmod_kfunc.h" + +#if defined(__TARGET_ARCH_x86) && defined(__BPF_FEATURE_STACK_ARGUMENT) + +const volatile bool has_stack_arg = true; + +SEC("tc") +int test_stack_arg_scalar(struct __sk_buff *skb) +{ + return bpf_kfunc_call_stack_arg(1, 2, 3, 4, 5, 6, 7, 8); +} + +SEC("tc") +int test_stack_arg_ptr(struct __sk_buff *skb) +{ + struct prog_test_pass1 p = { .x0 = 10, .x1 = 20 }; + + return bpf_kfunc_call_stack_arg_ptr(1, 2, 3, 4, 5, &p); +} + +SEC("tc") +int test_stack_arg_mix(struct __sk_buff *skb) +{ + struct prog_test_pass1 p = { .x0 = 10 }; + struct prog_test_pass1 q = { .x1 = 20 }; + + return bpf_kfunc_call_stack_arg_mix(1, 2, 3, 4, 5, &p, 6, &q); +} + +#else + +const volatile bool has_stack_arg = false; + +SEC("tc") +int test_stack_arg_scalar(struct __sk_buff *skb) +{ + return 0; +} + +SEC("tc") +int test_stack_arg_ptr(struct __sk_buff *skb) +{ + return 0; +} + +SEC("tc") +int test_stack_arg_mix(struct __sk_buff *skb) +{ + return 0; +} + +#endif + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c index 061356f10093..d88ab1dc5106 100644 --- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c +++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c @@ -824,6 +824,25 @@ __bpf_kfunc int bpf_kfunc_call_test5(u8 a, u16 b, u32 c) return 0; } +__bpf_kfunc u64 bpf_kfunc_call_stack_arg(u64 a, u64 b, u64 c, u64 d, + u64 e, u64 f, u64 g, u64 h) +{ + return a + b + c + d + e + f + g + h; +} + +__bpf_kfunc u64 bpf_kfunc_call_stack_arg_ptr(u64 a, u64 b, u64 c, u64 d, u64 e, + struct prog_test_pass1 *p) +{ + return a + b + c + d + e + p->x0 + p->x1; +} + +__bpf_kfunc u64 bpf_kfunc_call_stack_arg_mix(u64 a, u64 b, u64 c, u64 d, u64 e, + struct prog_test_pass1 *p, u64 f, + struct prog_test_pass1 *q) +{ + return a + b + c + d + e + p->x0 + f + q->x1; +} + static struct prog_test_ref_kfunc prog_test_struct = { .a = 42, .b = 108, @@ -1287,6 +1306,9 @@ BTF_ID_FLAGS(func, bpf_kfunc_call_test2) BTF_ID_FLAGS(func, bpf_kfunc_call_test3) BTF_ID_FLAGS(func, bpf_kfunc_call_test4) BTF_ID_FLAGS(func, bpf_kfunc_call_test5) +BTF_ID_FLAGS(func, bpf_kfunc_call_stack_arg) +BTF_ID_FLAGS(func, bpf_kfunc_call_stack_arg_ptr) +BTF_ID_FLAGS(func, bpf_kfunc_call_stack_arg_mix) BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_pass1) BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail1) BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail2) diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h b/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h index aa0b8d41e71b..f93cf2db12b2 100644 --- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h +++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h @@ -111,6 +111,13 @@ int bpf_kfunc_call_test2(struct sock *sk, __u32 a, __u32 b) __ksym; struct sock *bpf_kfunc_call_test3(struct sock *sk) __ksym; long bpf_kfunc_call_test4(signed char a, short b, int c, long d) __ksym; int bpf_kfunc_call_test5(__u8 a, __u16 b, __u32 c) __ksym; +__u64 bpf_kfunc_call_stack_arg(__u64 a, __u64 b, __u64 c, __u64 d, + __u64 e, __u64 f, __u64 g, __u64 h) __ksym; +__u64 bpf_kfunc_call_stack_arg_ptr(__u64 a, __u64 b, __u64 c, __u64 d, __u64 e, + struct prog_test_pass1 *p) __ksym; +__u64 bpf_kfunc_call_stack_arg_mix(__u64 a, __u64 b, __u64 c, __u64 d, __u64 e, + struct prog_test_pass1 *p, __u64 f, + struct prog_test_pass1 *q) __ksym; void bpf_kfunc_call_test_pass_ctx(struct __sk_buff *skb) __ksym; void bpf_kfunc_call_test_pass1(struct prog_test_pass1 *p) __ksym; -- 2.52.0