From: Andrii Nakryiko Date: Fri, 24 May 2019 18:59:04 +0000 (-0700) Subject: selftests/bpf: add btf_dump BTF-to-C conversion tests X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=2d2a3ad872f884d618f11e1a2028cff862503dcd;p=openwrt%2Fstaging%2Fblogic.git selftests/bpf: add btf_dump BTF-to-C conversion tests Add new test_btf_dump set of tests, validating BTF-to-C conversion correctness. Tests rely on clang to generate BTF from provided C test cases. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov --- diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore index 138b6c063916..b3da2ffdc158 100644 --- a/tools/testing/selftests/bpf/.gitignore +++ b/tools/testing/selftests/bpf/.gitignore @@ -36,3 +36,4 @@ alu32 libbpf.pc libbpf.so.* test_hashmap +test_btf_dump diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index ddae06498a00..cd23758e8b7a 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -23,7 +23,8 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test test_align test_verifier_log test_dev_cgroup test_tcpbpf_user \ test_sock test_btf test_sockmap test_lirc_mode2_user get_cgroup_id_user \ test_socket_cookie test_cgroup_storage test_select_reuseport test_section_names \ - test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap + test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \ + test_btf_dump BPF_OBJ_FILES = $(patsubst %.c,%.o, $(notdir $(wildcard progs/*.c))) TEST_GEN_FILES = $(BPF_OBJ_FILES) diff --git a/tools/testing/selftests/bpf/progs/btf_dump_test_case_bitfields.c b/tools/testing/selftests/bpf/progs/btf_dump_test_case_bitfields.c new file mode 100644 index 000000000000..8f44767a75fa --- /dev/null +++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_bitfields.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) + +/* + * BTF-to-C dumper tests for bitfield. + * + * Copyright (c) 2019 Facebook + */ +#include + +/* ----- START-EXPECTED-OUTPUT ----- */ +/* + *struct bitfields_only_mixed_types { + * int a: 3; + * long int b: 2; + * _Bool c: 1; + * enum { + * A = 0, + * B = 1, + * } d: 1; + * short e: 5; + * int: 20; + * unsigned int f: 30; + *}; + * + */ +/* ------ END-EXPECTED-OUTPUT ------ */ + +struct bitfields_only_mixed_types { + int a: 3; + long int b: 2; + bool c: 1; /* it's really a _Bool type */ + enum { + A, /* A = 0, dumper is very explicit */ + B, /* B = 1, same */ + } d: 1; + short e: 5; + /* 20-bit padding here */ + unsigned f: 30; /* this gets aligned on 4-byte boundary */ +}; + +/* ----- START-EXPECTED-OUTPUT ----- */ +/* + *struct bitfield_mixed_with_others { + * char: 4; + * int a: 4; + * short b; + * long int c; + * long int d: 8; + * int e; + * int f; + *}; + * + */ +/* ------ END-EXPECTED-OUTPUT ------ */ +struct bitfield_mixed_with_others { + long: 4; /* char is enough as a backing field */ + int a: 4; + /* 8-bit implicit padding */ + short b; /* combined with previous bitfield */ + /* 4 more bytes of implicit padding */ + long c; + long d: 8; + /* 24 bits implicit padding */ + int e; /* combined with previous bitfield */ + int f; + /* 4 bytes of padding */ +}; + +/* ----- START-EXPECTED-OUTPUT ----- */ +/* + *struct bitfield_flushed { + * int a: 4; + * long: 60; + * long int b: 16; + *}; + * + */ +/* ------ END-EXPECTED-OUTPUT ------ */ +struct bitfield_flushed { + int a: 4; + long: 0; /* flush until next natural alignment boundary */ + long b: 16; +}; + +int f(struct { + struct bitfields_only_mixed_types _1; + struct bitfield_mixed_with_others _2; + struct bitfield_flushed _3; +} *_) +{ + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/btf_dump_test_case_multidim.c b/tools/testing/selftests/bpf/progs/btf_dump_test_case_multidim.c new file mode 100644 index 000000000000..ba97165bdb28 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_multidim.c @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) + +/* + * BTF-to-C dumper test for multi-dimensional array output. + * + * Copyright (c) 2019 Facebook + */ +/* ----- START-EXPECTED-OUTPUT ----- */ +typedef int arr_t[2]; + +typedef int multiarr_t[3][4][5]; + +typedef int *ptr_arr_t[6]; + +typedef int *ptr_multiarr_t[7][8][9][10]; + +typedef int * (*fn_ptr_arr_t[11])(); + +typedef int * (*fn_ptr_multiarr_t[12][13])(); + +struct root_struct { + arr_t _1; + multiarr_t _2; + ptr_arr_t _3; + ptr_multiarr_t _4; + fn_ptr_arr_t _5; + fn_ptr_multiarr_t _6; +}; + +/* ------ END-EXPECTED-OUTPUT ------ */ + +int f(struct root_struct *s) +{ + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/btf_dump_test_case_namespacing.c b/tools/testing/selftests/bpf/progs/btf_dump_test_case_namespacing.c new file mode 100644 index 000000000000..92a4ad428710 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_namespacing.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) + +/* + * BTF-to-C dumper test validating no name versioning happens between + * independent C namespaces (struct/union/enum vs typedef/enum values). + * + * Copyright (c) 2019 Facebook + */ +/* ----- START-EXPECTED-OUTPUT ----- */ +struct S { + int S; + int U; +}; + +typedef struct S S; + +union U { + int S; + int U; +}; + +typedef union U U; + +enum E { + V = 0, +}; + +typedef enum E E; + +struct A {}; + +union B {}; + +enum C { + A = 1, + B = 2, + C = 3, +}; + +struct X {}; + +union Y {}; + +enum Z; + +typedef int X; + +typedef int Y; + +typedef int Z; + +/*------ END-EXPECTED-OUTPUT ------ */ + +int f(struct { + struct S _1; + S _2; + union U _3; + U _4; + enum E _5; + E _6; + struct A a; + union B b; + enum C c; + struct X x; + union Y y; + enum Z *z; + X xx; + Y yy; + Z zz; +} *_) +{ + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/btf_dump_test_case_ordering.c b/tools/testing/selftests/bpf/progs/btf_dump_test_case_ordering.c new file mode 100644 index 000000000000..7c95702ee4cb --- /dev/null +++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_ordering.c @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) + +/* + * BTF-to-C dumper test for topological sorting of dependent structs. + * + * Copyright (c) 2019 Facebook + */ +/* ----- START-EXPECTED-OUTPUT ----- */ +struct s1 {}; + +struct s3; + +struct s4; + +struct s2 { + struct s2 *s2; + struct s3 *s3; + struct s4 *s4; +}; + +struct s3 { + struct s1 s1; + struct s2 s2; +}; + +struct s4 { + struct s1 s1; + struct s3 s3; +}; + +struct list_head { + struct list_head *next; + struct list_head *prev; +}; + +struct hlist_node { + struct hlist_node *next; + struct hlist_node **pprev; +}; + +struct hlist_head { + struct hlist_node *first; +}; + +struct callback_head { + struct callback_head *next; + void (*func)(struct callback_head *); +}; + +struct root_struct { + struct s4 s4; + struct list_head l; + struct hlist_node n; + struct hlist_head h; + struct callback_head cb; +}; + +/*------ END-EXPECTED-OUTPUT ------ */ + +int f(struct root_struct *root) +{ + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/btf_dump_test_case_packing.c b/tools/testing/selftests/bpf/progs/btf_dump_test_case_packing.c new file mode 100644 index 000000000000..1cef3bec1dc7 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_packing.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) + +/* + * BTF-to-C dumper tests for struct packing determination. + * + * Copyright (c) 2019 Facebook + */ +/* ----- START-EXPECTED-OUTPUT ----- */ +struct packed_trailing_space { + int a; + short b; +} __attribute__((packed)); + +struct non_packed_trailing_space { + int a; + short b; +}; + +struct packed_fields { + short a; + int b; +} __attribute__((packed)); + +struct non_packed_fields { + short a; + int b; +}; + +struct nested_packed { + char: 4; + int a: 4; + long int b; + struct { + char c; + int d; + } __attribute__((packed)) e; +} __attribute__((packed)); + +union union_is_never_packed { + int a: 4; + char b; + char c: 1; +}; + +union union_does_not_need_packing { + struct { + long int a; + int b; + } __attribute__((packed)); + int c; +}; + +union jump_code_union { + char code[5]; + struct { + char jump; + int offset; + } __attribute__((packed)); +}; + +/*------ END-EXPECTED-OUTPUT ------ */ + +int f(struct { + struct packed_trailing_space _1; + struct non_packed_trailing_space _2; + struct packed_fields _3; + struct non_packed_fields _4; + struct nested_packed _5; + union union_is_never_packed _6; + union union_does_not_need_packing _7; + union jump_code_union _8; +} *_) +{ + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/btf_dump_test_case_padding.c b/tools/testing/selftests/bpf/progs/btf_dump_test_case_padding.c new file mode 100644 index 000000000000..3a62119c7498 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_padding.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) + +/* + * BTF-to-C dumper tests for implicit and explicit padding between fields and + * at the end of a struct. + * + * Copyright (c) 2019 Facebook + */ +/* ----- START-EXPECTED-OUTPUT ----- */ +struct padded_implicitly { + int a; + long int b; + char c; +}; + +/* ------ END-EXPECTED-OUTPUT ------ */ + +/* ----- START-EXPECTED-OUTPUT ----- */ +/* + *struct padded_explicitly { + * int a; + * int: 32; + * int b; + *}; + * + */ +/* ------ END-EXPECTED-OUTPUT ------ */ + +struct padded_explicitly { + int a; + int: 1; /* algo will explicitly pad with full 32 bits here */ + int b; +}; + +/* ----- START-EXPECTED-OUTPUT ----- */ +/* + *struct padded_a_lot { + * int a; + * long: 32; + * long: 64; + * long: 64; + * int b; + *}; + * + */ +/* ------ END-EXPECTED-OUTPUT ------ */ + +struct padded_a_lot { + int a; + /* 32 bit of implicit padding here, which algo will make explicit */ + long: 64; + long: 64; + int b; +}; + +/* ----- START-EXPECTED-OUTPUT ----- */ +/* + *struct padded_cache_line { + * int a; + * long: 32; + * long: 64; + * long: 64; + * long: 64; + * int b; + *}; + * + */ +/* ------ END-EXPECTED-OUTPUT ------ */ + +struct padded_cache_line { + int a; + int b __attribute__((aligned(32))); +}; + +/* ----- START-EXPECTED-OUTPUT ----- */ +/* + *struct zone_padding { + * char x[0]; + *}; + * + *struct zone { + * int a; + * short b; + * short: 16; + * struct zone_padding __pad__; + *}; + * + */ +/* ------ END-EXPECTED-OUTPUT ------ */ + +struct zone_padding { + char x[0]; +} __attribute__((__aligned__(8))); + +struct zone { + int a; + short b; + short: 16; + struct zone_padding __pad__; +}; + +int f(struct { + struct padded_implicitly _1; + struct padded_explicitly _2; + struct padded_a_lot _3; + struct padded_cache_line _4; + struct zone _5; +} *_) +{ + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c b/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c new file mode 100644 index 000000000000..d4a02fe44a12 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c @@ -0,0 +1,229 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) + +/* + * BTF-to-C dumper test for majority of C syntax quirks. + * + * Copyright (c) 2019 Facebook + */ +/* ----- START-EXPECTED-OUTPUT ----- */ +enum e1 { + A = 0, + B = 1, +}; + +enum e2 { + C = 100, + D = -100, + E = 0, +}; + +typedef enum e2 e2_t; + +typedef enum { + F = 0, + G = 1, + H = 2, +} e3_t; + +typedef int int_t; + +typedef volatile const int * volatile const crazy_ptr_t; + +typedef int *****we_need_to_go_deeper_ptr_t; + +typedef volatile const we_need_to_go_deeper_ptr_t * restrict * volatile * const * restrict volatile * restrict const * volatile const * restrict volatile const how_about_this_ptr_t; + +typedef int *ptr_arr_t[10]; + +typedef void (*fn_ptr1_t)(int); + +typedef void (*printf_fn_t)(const char *, ...); + +/* ------ END-EXPECTED-OUTPUT ------ */ +/* + * While previous function pointers are pretty trivial (C-syntax-level + * trivial), the following are deciphered here for future generations: + * + * - `fn_ptr2_t`: function, taking anonymous struct as a first arg and pointer + * to a function, that takes int and returns int, as a second arg; returning + * a pointer to a const pointer to a char. Equivalent to: + * typedef struct { int a; } s_t; + * typedef int (*fn_t)(int); + * typedef char * const * (*fn_ptr2_t)(s_t, fn_t); + * + * - `fn_complext_t`: pointer to a function returning struct and accepting + * union and struct. All structs and enum are anonymous and defined inline. + * + * - `signal_t: pointer to a function accepting a pointer to a function as an + * argument and returning pointer to a function as a result. Sane equivalent: + * typedef void (*signal_handler_t)(int); + * typedef signal_handler_t (*signal_ptr_t)(int, signal_handler_t); + * + * - fn_ptr_arr1_t: array of pointers to a function accepting pointer to + * a pointer to an int and returning pointer to a char. Easy. + * + * - fn_ptr_arr2_t: array of const pointers to a function taking no arguments + * and returning a const pointer to a function, that takes pointer to a + * `int -> char *` function and returns pointer to a char. Equivalent: + * typedef char * (*fn_input_t)(int); + * typedef char * (*fn_output_outer_t)(fn_input_t); + * typedef const fn_output_outer_t (* fn_output_inner_t)(); + * typedef const fn_output_inner_t fn_ptr_arr2_t[5]; + */ +/* ----- START-EXPECTED-OUTPUT ----- */ +typedef char * const * (*fn_ptr2_t)(struct { + int a; +}, int (*)(int)); + +typedef struct { + int a; + void (*b)(int, struct { + int c; + }, union { + char d; + int e[5]; + }); +} (*fn_complex_t)(union { + void *f; + char g[16]; +}, struct { + int h; +}); + +typedef void (* (*signal_t)(int, void (*)(int)))(int); + +typedef char * (*fn_ptr_arr1_t[10])(int **); + +typedef char * (* const (* const fn_ptr_arr2_t[5])())(char * (*)(int)); + +struct struct_w_typedefs { + int_t a; + crazy_ptr_t b; + we_need_to_go_deeper_ptr_t c; + how_about_this_ptr_t d; + ptr_arr_t e; + fn_ptr1_t f; + printf_fn_t g; + fn_ptr2_t h; + fn_complex_t i; + signal_t j; + fn_ptr_arr1_t k; + fn_ptr_arr2_t l; +}; + +typedef struct { + int x; + int y; + int z; +} anon_struct_t; + +struct struct_fwd; + +typedef struct struct_fwd struct_fwd_t; + +typedef struct struct_fwd *struct_fwd_ptr_t; + +union union_fwd; + +typedef union union_fwd union_fwd_t; + +typedef union union_fwd *union_fwd_ptr_t; + +struct struct_empty {}; + +struct struct_simple { + int a; + char b; + const int_t *p; + struct struct_empty s; + enum e2 e; + enum { + ANON_VAL1 = 1, + ANON_VAL2 = 2, + } f; + int arr1[13]; + enum e2 arr2[5]; +}; + +union union_empty {}; + +union union_simple { + void *ptr; + int num; + int_t num2; + union union_empty u; +}; + +struct struct_in_struct { + struct struct_simple simple; + union union_simple also_simple; + struct { + int a; + } not_so_hard_as_well; + union { + int b; + int c; + } anon_union_is_good; + struct { + int d; + int e; + }; + union { + int f; + int g; + }; +}; + +struct struct_with_embedded_stuff { + int a; + struct { + int b; + struct { + struct struct_with_embedded_stuff *c; + const char *d; + } e; + union { + volatile long int f; + void * restrict g; + }; + }; + union { + const int_t *h; + void (*i)(char, int, void *); + } j; + enum { + K = 100, + L = 200, + } m; + char n[16]; + struct { + char o; + int p; + void (*q)(int); + } r[5]; + struct struct_in_struct s[10]; + int t[11]; +}; + +struct root_struct { + enum e1 _1; + enum e2 _2; + e2_t _2_1; + e3_t _2_2; + struct struct_w_typedefs _3; + anon_struct_t _7; + struct struct_fwd *_8; + struct_fwd_t *_9; + struct_fwd_ptr_t _10; + union union_fwd *_11; + union_fwd_t *_12; + union_fwd_ptr_t _13; + struct struct_with_embedded_stuff _14; +}; + +/* ------ END-EXPECTED-OUTPUT ------ */ + +int f(struct root_struct *s) +{ + return 0; +} diff --git a/tools/testing/selftests/bpf/test_btf_dump.c b/tools/testing/selftests/bpf/test_btf_dump.c new file mode 100644 index 000000000000..8f850823d35f --- /dev/null +++ b/tools/testing/selftests/bpf/test_btf_dump.c @@ -0,0 +1,143 @@ +#include +#include +#include +#include +#include +#include +#include + +#define CHECK(condition, format...) ({ \ + int __ret = !!(condition); \ + if (__ret) { \ + fprintf(stderr, "%s:%d:FAIL ", __func__, __LINE__); \ + fprintf(stderr, format); \ + } \ + __ret; \ +}) + +void btf_dump_printf(void *ctx, const char *fmt, va_list args) +{ + vfprintf(ctx, fmt, args); +} + +struct btf_dump_test_case { + const char *name; + struct btf_dump_opts opts; +} btf_dump_test_cases[] = { + {.name = "btf_dump_test_case_syntax", .opts = {}}, + {.name = "btf_dump_test_case_ordering", .opts = {}}, + {.name = "btf_dump_test_case_padding", .opts = {}}, + {.name = "btf_dump_test_case_packing", .opts = {}}, + {.name = "btf_dump_test_case_bitfields", .opts = {}}, + {.name = "btf_dump_test_case_multidim", .opts = {}}, + {.name = "btf_dump_test_case_namespacing", .opts = {}}, +}; + +static int btf_dump_all_types(const struct btf *btf, + const struct btf_dump_opts *opts) +{ + size_t type_cnt = btf__get_nr_types(btf); + struct btf_dump *d; + int err = 0, id; + + d = btf_dump__new(btf, NULL, opts, btf_dump_printf); + if (IS_ERR(d)) + return PTR_ERR(d); + + for (id = 1; id <= type_cnt; id++) { + err = btf_dump__dump_type(d, id); + if (err) + goto done; + } + +done: + btf_dump__free(d); + return err; +} + +int test_btf_dump_case(int n, struct btf_dump_test_case *test_case) +{ + char test_file[256], out_file[256], diff_cmd[1024]; + struct btf *btf = NULL; + int err = 0, fd = -1; + FILE *f = NULL; + + fprintf(stderr, "Test case #%d (%s): ", n, test_case->name); + + snprintf(test_file, sizeof(test_file), "%s.o", test_case->name); + + btf = btf__parse_elf(test_file, NULL); + if (CHECK(IS_ERR(btf), + "failed to load test BTF: %ld\n", PTR_ERR(btf))) { + err = -PTR_ERR(btf); + btf = NULL; + goto done; + } + + snprintf(out_file, sizeof(out_file), + "/tmp/%s.output.XXXXXX", test_case->name); + fd = mkstemp(out_file); + if (CHECK(fd < 0, "failed to create temp output file: %d\n", fd)) { + err = fd; + goto done; + } + f = fdopen(fd, "w"); + if (CHECK(f == NULL, "failed to open temp output file: %s(%d)\n", + strerror(errno), errno)) { + close(fd); + goto done; + } + + test_case->opts.ctx = f; + err = btf_dump_all_types(btf, &test_case->opts); + fclose(f); + close(fd); + if (CHECK(err, "failure during C dumping: %d\n", err)) { + goto done; + } + + snprintf(test_file, sizeof(test_file), "progs/%s.c", test_case->name); + /* + * Diff test output and expected test output, contained between + * START-EXPECTED-OUTPUT and END-EXPECTED-OUTPUT lines in test case. + * For expected output lines, everything before '*' is stripped out. + * Also lines containing comment start and comment end markers are + * ignored. + */ + snprintf(diff_cmd, sizeof(diff_cmd), + "awk '/START-EXPECTED-OUTPUT/{out=1;next} " + "/END-EXPECTED-OUTPUT/{out=0} " + "/\\/\\*|\\*\\//{next} " /* ignore comment start/end lines */ + "out {sub(/^[ \\t]*\\*/, \"\"); print}' '%s' | diff -u - '%s'", + test_file, out_file); + err = system(diff_cmd); + if (CHECK(err, + "differing test output, output=%s, err=%d, diff cmd:\n%s\n", + out_file, err, diff_cmd)) + goto done; + + remove(out_file); + fprintf(stderr, "OK\n"); + +done: + btf__free(btf); + return err; +} + +int main() { + int test_case_cnt, i, err, failed = 0; + + test_case_cnt = sizeof(btf_dump_test_cases) / + sizeof(btf_dump_test_cases[0]); + + for (i = 0; i < test_case_cnt; i++) { + err = test_btf_dump_case(i, &btf_dump_test_cases[i]); + if (err) + failed++; + } + + fprintf(stderr, "%d tests succeeded, %d tests failed.\n", + test_case_cnt - failed, failed); + + return failed; +}