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 | 132 +++++++++++ tools/testing/selftests/bpf/progs/stack_arg.c | 212 ++++++++++++++++++ .../selftests/bpf/progs/stack_arg_kfunc.c | 164 ++++++++++++++ .../selftests/bpf/test_kmods/bpf_testmod.c | 65 ++++++ .../bpf/test_kmods/bpf_testmod_kfunc.h | 20 +- 5 files changed, 592 insertions(+), 1 deletion(-) 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..1af5e5c91e0d --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/stack_arg.c @@ -0,0 +1,132 @@ +// 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 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_bpf2bpf(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_bpf2bpf_ptr_stack_arg, 45); + run_subtest(skel->progs.test_bpf2bpf_mix_stack_args, 51); + run_subtest(skel->progs.test_bpf2bpf_nesting_stack_arg, 50); + run_subtest(skel->progs.test_bpf2bpf_dynptr_stack_arg, 69); + +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); + run_subtest(skel->progs.test_stack_arg_dynptr, 69); + run_subtest(skel->progs.test_stack_arg_mem, 151); + run_subtest(skel->progs.test_stack_arg_iter, 115); + run_subtest(skel->progs.test_stack_arg_const_str, 15); + run_subtest(skel->progs.test_stack_arg_timer, 15); + +out: + stack_arg_kfunc__destroy(skel); +} + +void test_stack_arg(void) +{ + 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("bpf2bpf")) + test_bpf2bpf(); + 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..c6bf89c3a0db --- /dev/null +++ b/tools/testing/selftests/bpf/progs/stack_arg.c @@ -0,0 +1,212 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include +#include "bpf_kfuncs.h" + +#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 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); +} + +struct test_data { + long x; + long y; +}; + +/* 1 + 2 + 3 + 4 + 5 + 10 + 20 = 45 */ +__noinline static long func_with_ptr_stack_arg(long a, long b, long c, long d, + long e, struct test_data *p) +{ + return a + b + c + d + e + p->x + p->y; +} + +__noinline long global_ptr_stack_arg(long a, long b, long c, long d, long e) +{ + struct test_data data = { .x = 10, .y = 20 }; + + return func_with_ptr_stack_arg(a, b, c, d, e, &data); +} + +SEC("tc") +int test_bpf2bpf_ptr_stack_arg(void) +{ + return global_ptr_stack_arg(1, 2, 3, 4, 5); +} + +/* 1 + 2 + 3 + 4 + 5 + 10 + 6 + 20 = 51 */ +__noinline static long func_with_mix_stack_args(long a, long b, long c, long d, + long e, struct test_data *p, + long f, struct test_data *q) +{ + return a + b + c + d + e + p->x + f + q->y; +} + +__noinline long global_mix_stack_args(long a, long b, long c, long d, long e) +{ + struct test_data p = { .x = 10 }; + struct test_data q = { .y = 20 }; + + return func_with_mix_stack_args(a, b, c, d, e, &p, e + 1, &q); +} + +SEC("tc") +int test_bpf2bpf_mix_stack_args(void) +{ + return global_mix_stack_args(1, 2, 3, 4, 5); +} + +/* + * Nesting test: func_outer calls func_inner, both with struct pointer + * as stack arg. + * + * func_inner: (a+1) + (b+1) + (c+1) + (d+1) + (e+1) + p->x + p->y + * = 2 + 3 + 4 + 5 + 6 + 10 + 20 = 50 + */ +__noinline static long func_inner_ptr(long a, long b, long c, long d, + long e, struct test_data *p) +{ + return a + b + c + d + e + p->x + p->y; +} + +__noinline static long func_outer_ptr(long a, long b, long c, long d, + long e, struct test_data *p) +{ + return func_inner_ptr(a + 1, b + 1, c + 1, d + 1, e + 1, p); +} + +__noinline long global_nesting_ptr(long a, long b, long c, long d, long e) +{ + struct test_data data = { .x = 10, .y = 20 }; + + return func_outer_ptr(a, b, c, d, e, &data); +} + +SEC("tc") +int test_bpf2bpf_nesting_stack_arg(void) +{ + return global_nesting_ptr(1, 2, 3, 4, 5); +} + +/* 1 + 2 + 3 + 4 + 5 + sizeof(pkt_v4) = 15 + 54 = 69 */ +__noinline static long func_with_dynptr(long a, long b, long c, long d, + long e, struct bpf_dynptr *ptr) +{ + return a + b + c + d + e + bpf_dynptr_size(ptr); +} + +__noinline long global_dynptr_stack_arg(void *ctx __arg_ctx, long a, long b, + long c, long d) +{ + struct bpf_dynptr ptr; + + bpf_dynptr_from_skb(ctx, 0, &ptr); + return func_with_dynptr(a, b, c, d, d + 1, &ptr); +} + +SEC("tc") +int test_bpf2bpf_dynptr_stack_arg(struct __sk_buff *skb) +{ + return global_dynptr_stack_arg(skb, 1, 2, 3, 4); +} + +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_global_many_args(void) +{ + return 0; +} + +SEC("tc") +int test_bpf2bpf_ptr_stack_arg(void) +{ + return 0; +} + +SEC("tc") +int test_bpf2bpf_mix_stack_args(void) +{ + return 0; +} + +SEC("tc") +int test_bpf2bpf_nesting_stack_arg(void) +{ + return 0; +} + +SEC("tc") +int test_bpf2bpf_dynptr_stack_arg(struct __sk_buff *skb) +{ + 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..6cc404d57863 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/stack_arg_kfunc.c @@ -0,0 +1,164 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include "bpf_kfuncs.h" +#include "../test_kmods/bpf_testmod_kfunc.h" + +#if defined(__TARGET_ARCH_x86) && defined(__BPF_FEATURE_STACK_ARGUMENT) + +const volatile bool has_stack_arg = true; + +struct bpf_iter_testmod_seq { + u64 :64; + u64 :64; +}; + +extern int bpf_iter_testmod_seq_new(struct bpf_iter_testmod_seq *it, s64 value, int cnt) __ksym; +extern int *bpf_iter_testmod_seq_next(struct bpf_iter_testmod_seq *it) __ksym; +extern void bpf_iter_testmod_seq_destroy(struct bpf_iter_testmod_seq *it) __ksym; + +struct timer_map_value { + struct bpf_timer timer; +}; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, int); + __type(value, struct timer_map_value); +} kfunc_timer_map SEC(".maps"); + +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); +} + +/* 1 + 2 + 3 + 4 + 5 + sizeof(pkt_v4) = 15 + 54 = 69 */ +SEC("tc") +int test_stack_arg_dynptr(struct __sk_buff *skb) +{ + struct bpf_dynptr ptr; + + bpf_dynptr_from_skb(skb, 0, &ptr); + return bpf_kfunc_call_stack_arg_dynptr(1, 2, 3, 4, 5, &ptr); +} + +/* 1 + 2 + 3 + 4 + 5 + (1 + 2 + ... + 16) = 15 + 136 = 151 */ +SEC("tc") +int test_stack_arg_mem(struct __sk_buff *skb) +{ + char buf[16] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}; + + return bpf_kfunc_call_stack_arg_mem(1, 2, 3, 4, 5, buf, sizeof(buf)); +} + +/* 1 + 2 + 3 + 4 + 5 + 100 = 115 */ +SEC("tc") +int test_stack_arg_iter(struct __sk_buff *skb) +{ + struct bpf_iter_testmod_seq it; + u64 ret; + + bpf_iter_testmod_seq_new(&it, 100, 10); + ret = bpf_kfunc_call_stack_arg_iter(1, 2, 3, 4, 5, &it); + bpf_iter_testmod_seq_destroy(&it); + return ret; +} + +const char cstr[] = "hello"; + +/* 1 + 2 + 3 + 4 + 5 = 15 */ +SEC("tc") +int test_stack_arg_const_str(struct __sk_buff *skb) +{ + return bpf_kfunc_call_stack_arg_const_str(1, 2, 3, 4, 5, cstr); +} + +/* 1 + 2 + 3 + 4 + 5 = 15 */ +SEC("tc") +int test_stack_arg_timer(struct __sk_buff *skb) +{ + struct timer_map_value *val; + int key = 0; + + val = bpf_map_lookup_elem(&kfunc_timer_map, &key); + if (!val) + return 0; + return bpf_kfunc_call_stack_arg_timer(1, 2, 3, 4, 5, &val->timer); +} + +#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; +} + +SEC("tc") +int test_stack_arg_dynptr(struct __sk_buff *skb) +{ + return 0; +} + +SEC("tc") +int test_stack_arg_mem(struct __sk_buff *skb) +{ + return 0; +} + +SEC("tc") +int test_stack_arg_iter(struct __sk_buff *skb) +{ + return 0; +} + +SEC("tc") +int test_stack_arg_const_str(struct __sk_buff *skb) +{ + return 0; +} + +SEC("tc") +int test_stack_arg_timer(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..4fcdb13e4a9a 100644 --- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c +++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c @@ -824,6 +824,63 @@ __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; +} + +__bpf_kfunc u64 bpf_kfunc_call_stack_arg_dynptr(u64 a, u64 b, u64 c, u64 d, u64 e, + struct bpf_dynptr *ptr) +{ + const struct bpf_dynptr_kern *kern_ptr = (void *)ptr; + + return a + b + c + d + e + (kern_ptr->size & 0xFFFFFF); +} + +__bpf_kfunc u64 bpf_kfunc_call_stack_arg_mem(u64 a, u64 b, u64 c, u64 d, u64 e, + void *mem, int mem__sz) +{ + const unsigned char *p = mem; + u64 sum = a + b + c + d + e; + int i; + + for (i = 0; i < mem__sz; i++) + sum += p[i]; + return sum; +} + +__bpf_kfunc u64 bpf_kfunc_call_stack_arg_iter(u64 a, u64 b, u64 c, u64 d, u64 e, + struct bpf_iter_testmod_seq *it__iter) +{ + return a + b + c + d + e + it__iter->value; +} + +__bpf_kfunc u64 bpf_kfunc_call_stack_arg_const_str(u64 a, u64 b, u64 c, u64 d, u64 e, + const char *str__str) +{ + return a + b + c + d + e; +} + +__bpf_kfunc u64 bpf_kfunc_call_stack_arg_timer(u64 a, u64 b, u64 c, u64 d, u64 e, + struct bpf_timer *timer) +{ + return a + b + c + d + e; +} + static struct prog_test_ref_kfunc prog_test_struct = { .a = 42, .b = 108, @@ -1287,6 +1344,14 @@ 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_stack_arg_dynptr) +BTF_ID_FLAGS(func, bpf_kfunc_call_stack_arg_mem) +BTF_ID_FLAGS(func, bpf_kfunc_call_stack_arg_iter) +BTF_ID_FLAGS(func, bpf_kfunc_call_stack_arg_const_str) +BTF_ID_FLAGS(func, bpf_kfunc_call_stack_arg_timer) 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..2c1cb118f886 100644 --- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h +++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h @@ -26,6 +26,8 @@ struct prog_test_ref_kfunc { }; #endif +struct bpf_iter_testmod_seq; + struct prog_test_pass1 { int x0; struct { @@ -111,7 +113,23 @@ 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; +__u64 bpf_kfunc_call_stack_arg_dynptr(__u64 a, __u64 b, __u64 c, __u64 d, __u64 e, + struct bpf_dynptr *ptr) __ksym; +__u64 bpf_kfunc_call_stack_arg_mem(__u64 a, __u64 b, __u64 c, __u64 d, __u64 e, + void *mem, int mem__sz) __ksym; +__u64 bpf_kfunc_call_stack_arg_iter(__u64 a, __u64 b, __u64 c, __u64 d, __u64 e, + struct bpf_iter_testmod_seq *it__iter) __ksym; +__u64 bpf_kfunc_call_stack_arg_const_str(__u64 a, __u64 b, __u64 c, __u64 d, __u64 e, + const char *str__str) __ksym; +__u64 bpf_kfunc_call_stack_arg_timer(__u64 a, __u64 b, __u64 c, __u64 d, __u64 e, + struct bpf_timer *timer) __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; void bpf_kfunc_call_test_pass2(struct prog_test_pass2 *p) __ksym; -- 2.52.0