From 360301a6c21be87fe881546bd5f22eccf7a165c5 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 9 Jan 2020 22:41:24 -0800 Subject: [PATCH] selftests/bpf: Add unit tests for global functions test_global_func[12] - check 512 stack limit. test_global_func[34] - check 8 frame call chain limit. test_global_func5 - check that non-ctx pointer cannot be passed into a function that expects context. test_global_func6 - check that ctx pointer is unmodified. test_global_func7 - check that global function returns scalar. Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20200110064124.1760511-7-ast@kernel.org --- .../bpf/prog_tests/test_global_funcs.c | 82 +++++++++++++++++++ .../selftests/bpf/progs/test_global_func1.c | 45 ++++++++++ .../selftests/bpf/progs/test_global_func2.c | 4 + .../selftests/bpf/progs/test_global_func3.c | 65 +++++++++++++++ .../selftests/bpf/progs/test_global_func4.c | 4 + .../selftests/bpf/progs/test_global_func5.c | 31 +++++++ .../selftests/bpf/progs/test_global_func6.c | 31 +++++++ .../selftests/bpf/progs/test_global_func7.c | 18 ++++ 8 files changed, 280 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/test_global_funcs.c create mode 100644 tools/testing/selftests/bpf/progs/test_global_func1.c create mode 100644 tools/testing/selftests/bpf/progs/test_global_func2.c create mode 100644 tools/testing/selftests/bpf/progs/test_global_func3.c create mode 100644 tools/testing/selftests/bpf/progs/test_global_func4.c create mode 100644 tools/testing/selftests/bpf/progs/test_global_func5.c create mode 100644 tools/testing/selftests/bpf/progs/test_global_func6.c create mode 100644 tools/testing/selftests/bpf/progs/test_global_func7.c diff --git a/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c b/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c new file mode 100644 index 000000000000..25b068591e9a --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ +#include + +const char *err_str; +bool found; + +static int libbpf_debug_print(enum libbpf_print_level level, + const char *format, va_list args) +{ + char *log_buf; + + if (level != LIBBPF_WARN || + strcmp(format, "libbpf: \n%s\n")) { + vprintf(format, args); + return 0; + } + + log_buf = va_arg(args, char *); + if (!log_buf) + goto out; + if (strstr(log_buf, err_str) == 0) + found = true; +out: + printf(format, log_buf); + return 0; +} + +extern int extra_prog_load_log_flags; + +static int check_load(const char *file) +{ + struct bpf_prog_load_attr attr; + struct bpf_object *obj = NULL; + int err, prog_fd; + + memset(&attr, 0, sizeof(struct bpf_prog_load_attr)); + attr.file = file; + attr.prog_type = BPF_PROG_TYPE_UNSPEC; + attr.log_level = extra_prog_load_log_flags; + attr.prog_flags = BPF_F_TEST_RND_HI32; + found = false; + err = bpf_prog_load_xattr(&attr, &obj, &prog_fd); + bpf_object__close(obj); + return err; +} + +struct test_def { + const char *file; + const char *err_str; +}; + +void test_test_global_funcs(void) +{ + struct test_def tests[] = { + { "test_global_func1.o", "combined stack size of 4 calls is 544" }, + { "test_global_func2.o" }, + { "test_global_func3.o" , "the call stack of 8 frames" }, + { "test_global_func4.o" }, + { "test_global_func5.o" , "expected pointer to ctx, but got PTR" }, + { "test_global_func6.o" , "modified ctx ptr R2" }, + { "test_global_func7.o" , "foo() doesn't return scalar" }, + }; + libbpf_print_fn_t old_print_fn = NULL; + int err, i, duration = 0; + + old_print_fn = libbpf_set_print(libbpf_debug_print); + + for (i = 0; i < ARRAY_SIZE(tests); i++) { + const struct test_def *test = &tests[i]; + + if (!test__start_subtest(test->file)) + continue; + + err_str = test->err_str; + err = check_load(test->file); + CHECK_FAIL(!!err ^ !!err_str); + if (err_str) + CHECK(found, "", "expected string '%s'", err_str); + } + libbpf_set_print(old_print_fn); +} diff --git a/tools/testing/selftests/bpf/progs/test_global_func1.c b/tools/testing/selftests/bpf/progs/test_global_func1.c new file mode 100644 index 000000000000..97d57d6e244e --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_global_func1.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2020 Facebook */ +#include +#include +#include "bpf_helpers.h" + +#ifndef MAX_STACK +#define MAX_STACK (512 - 3 * 32 + 8) +#endif + +static __attribute__ ((noinline)) +int f0(int var, struct __sk_buff *skb) +{ + return skb->len; +} + +__attribute__ ((noinline)) +int f1(struct __sk_buff *skb) +{ + volatile char buf[MAX_STACK] = {}; + + return f0(0, skb) + skb->len; +} + +int f3(int, struct __sk_buff *skb, int); + +__attribute__ ((noinline)) +int f2(int val, struct __sk_buff *skb) +{ + return f1(skb) + f3(val, skb, 1); +} + +__attribute__ ((noinline)) +int f3(int val, struct __sk_buff *skb, int var) +{ + volatile char buf[MAX_STACK] = {}; + + return skb->ifindex * val * var; +} + +SEC("classifier/test") +int test_cls(struct __sk_buff *skb) +{ + return f0(1, skb) + f1(skb) + f2(2, skb) + f3(3, skb, 4); +} diff --git a/tools/testing/selftests/bpf/progs/test_global_func2.c b/tools/testing/selftests/bpf/progs/test_global_func2.c new file mode 100644 index 000000000000..2c18d82923a2 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_global_func2.c @@ -0,0 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2020 Facebook */ +#define MAX_STACK (512 - 3 * 32) +#include "test_global_func1.c" diff --git a/tools/testing/selftests/bpf/progs/test_global_func3.c b/tools/testing/selftests/bpf/progs/test_global_func3.c new file mode 100644 index 000000000000..514ecf9f51b0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_global_func3.c @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2020 Facebook */ +#include +#include +#include "bpf_helpers.h" + +__attribute__ ((noinline)) +int f1(struct __sk_buff *skb) +{ + return skb->len; +} + +__attribute__ ((noinline)) +int f2(int val, struct __sk_buff *skb) +{ + return f1(skb) + val; +} + +__attribute__ ((noinline)) +int f3(int val, struct __sk_buff *skb, int var) +{ + return f2(var, skb) + val; +} + +__attribute__ ((noinline)) +int f4(struct __sk_buff *skb) +{ + return f3(1, skb, 2); +} + +__attribute__ ((noinline)) +int f5(struct __sk_buff *skb) +{ + return f4(skb); +} + +__attribute__ ((noinline)) +int f6(struct __sk_buff *skb) +{ + return f5(skb); +} + +__attribute__ ((noinline)) +int f7(struct __sk_buff *skb) +{ + return f6(skb); +} + +#ifndef NO_FN8 +__attribute__ ((noinline)) +int f8(struct __sk_buff *skb) +{ + return f7(skb); +} +#endif + +SEC("classifier/test") +int test_cls(struct __sk_buff *skb) +{ +#ifndef NO_FN8 + return f8(skb); +#else + return f7(skb); +#endif +} diff --git a/tools/testing/selftests/bpf/progs/test_global_func4.c b/tools/testing/selftests/bpf/progs/test_global_func4.c new file mode 100644 index 000000000000..610f75edf276 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_global_func4.c @@ -0,0 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2020 Facebook */ +#define NO_FN8 +#include "test_global_func3.c" diff --git a/tools/testing/selftests/bpf/progs/test_global_func5.c b/tools/testing/selftests/bpf/progs/test_global_func5.c new file mode 100644 index 000000000000..86787c03cea8 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_global_func5.c @@ -0,0 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2020 Facebook */ +#include +#include +#include "bpf_helpers.h" + +__attribute__ ((noinline)) +int f1(struct __sk_buff *skb) +{ + return skb->len; +} + +int f3(int, struct __sk_buff *skb); + +__attribute__ ((noinline)) +int f2(int val, struct __sk_buff *skb) +{ + return f1(skb) + f3(val, (void *)&val); /* type mismatch */ +} + +__attribute__ ((noinline)) +int f3(int val, struct __sk_buff *skb) +{ + return skb->ifindex * val; +} + +SEC("classifier/test") +int test_cls(struct __sk_buff *skb) +{ + return f1(skb) + f2(2, skb) + f3(3, skb); +} diff --git a/tools/testing/selftests/bpf/progs/test_global_func6.c b/tools/testing/selftests/bpf/progs/test_global_func6.c new file mode 100644 index 000000000000..e215fb3e6f02 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_global_func6.c @@ -0,0 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2020 Facebook */ +#include +#include +#include "bpf_helpers.h" + +__attribute__ ((noinline)) +int f1(struct __sk_buff *skb) +{ + return skb->len; +} + +int f3(int, struct __sk_buff *skb); + +__attribute__ ((noinline)) +int f2(int val, struct __sk_buff *skb) +{ + return f1(skb) + f3(val, skb + 1); /* type mismatch */ +} + +__attribute__ ((noinline)) +int f3(int val, struct __sk_buff *skb) +{ + return skb->ifindex * val; +} + +SEC("classifier/test") +int test_cls(struct __sk_buff *skb) +{ + return f1(skb) + f2(2, skb) + f3(3, skb); +} diff --git a/tools/testing/selftests/bpf/progs/test_global_func7.c b/tools/testing/selftests/bpf/progs/test_global_func7.c new file mode 100644 index 000000000000..ff98d93916fd --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_global_func7.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2020 Facebook */ +#include +#include +#include "bpf_helpers.h" + +__attribute__ ((noinline)) +void foo(struct __sk_buff *skb) +{ + skb->tc_index = 0; +} + +SEC("classifier/test") +int test_cls(struct __sk_buff *skb) +{ + foo(skb); + return 0; +} -- 2.20.1