From: Andrii Nakryiko andriin@fb.com
mainline inclusion from mainline-5.11-rc1 commit 1306c980cf892bc17e7296d3e9ab8e9082f893a1 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Add re-usable btf_helpers.{c,h} to provide BTF-related testing routines. Start with adding a raw BTF dumping helpers.
Raw BTF dump is the most succinct and at the same time a very human-friendly way to validate exact contents of BTF types. Cross-validate raw BTF dump and writable BTF in a single selftest. Raw type dump checks also serve as a good self-documentation.
Signed-off-by: Andrii Nakryiko andrii@kernel.org Signed-off-by: Alexei Starovoitov ast@kernel.org Acked-by: Song Liu songliubraving@fb.com Link: https://lore.kernel.org/bpf/20201105043402.2530976-7-andrii@kernel.org (cherry picked from commit 1306c980cf892bc17e7296d3e9ab8e9082f893a1) Signed-off-by: Wang Yufen wangyufen@huawei.com --- tools/testing/selftests/bpf/Makefile | 2 +- tools/testing/selftests/bpf/btf_helpers.c | 200 ++++++++++++++++++ tools/testing/selftests/bpf/btf_helpers.h | 12 ++ .../selftests/bpf/prog_tests/btf_write.c | 43 ++++ 4 files changed, 256 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/btf_helpers.c create mode 100644 tools/testing/selftests/bpf/btf_helpers.h
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 6fabcc2f739b..080d9796e8e3 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -394,7 +394,7 @@ TRUNNER_TESTS_DIR := prog_tests TRUNNER_BPF_PROGS_DIR := progs TRUNNER_EXTRA_SOURCES := test_progs.c cgroup_helpers.c trace_helpers.c \ network_helpers.c testing_helpers.c \ - flow_dissector_load.h + btf_helpers.c flow_dissector_load.h TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read \ $(wildcard progs/btf_dump_test_case_*.c) TRUNNER_BPF_BUILD_RULE := CLANG_BPF_BUILD_RULE diff --git a/tools/testing/selftests/bpf/btf_helpers.c b/tools/testing/selftests/bpf/btf_helpers.c new file mode 100644 index 000000000000..abc3f6c04cfc --- /dev/null +++ b/tools/testing/selftests/bpf/btf_helpers.c @@ -0,0 +1,200 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ +#include <stdio.h> +#include <errno.h> +#include <bpf/btf.h> + +static const char * const btf_kind_str_mapping[] = { + [BTF_KIND_UNKN] = "UNKNOWN", + [BTF_KIND_INT] = "INT", + [BTF_KIND_PTR] = "PTR", + [BTF_KIND_ARRAY] = "ARRAY", + [BTF_KIND_STRUCT] = "STRUCT", + [BTF_KIND_UNION] = "UNION", + [BTF_KIND_ENUM] = "ENUM", + [BTF_KIND_FWD] = "FWD", + [BTF_KIND_TYPEDEF] = "TYPEDEF", + [BTF_KIND_VOLATILE] = "VOLATILE", + [BTF_KIND_CONST] = "CONST", + [BTF_KIND_RESTRICT] = "RESTRICT", + [BTF_KIND_FUNC] = "FUNC", + [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", + [BTF_KIND_VAR] = "VAR", + [BTF_KIND_DATASEC] = "DATASEC", +}; + +static const char *btf_kind_str(__u16 kind) +{ + if (kind > BTF_KIND_DATASEC) + return "UNKNOWN"; + return btf_kind_str_mapping[kind]; +} + +static const char *btf_int_enc_str(__u8 encoding) +{ + switch (encoding) { + case 0: + return "(none)"; + case BTF_INT_SIGNED: + return "SIGNED"; + case BTF_INT_CHAR: + return "CHAR"; + case BTF_INT_BOOL: + return "BOOL"; + default: + return "UNKN"; + } +} + +static const char *btf_var_linkage_str(__u32 linkage) +{ + switch (linkage) { + case BTF_VAR_STATIC: + return "static"; + case BTF_VAR_GLOBAL_ALLOCATED: + return "global-alloc"; + default: + return "(unknown)"; + } +} + +static const char *btf_func_linkage_str(const struct btf_type *t) +{ + switch (btf_vlen(t)) { + case BTF_FUNC_STATIC: + return "static"; + case BTF_FUNC_GLOBAL: + return "global"; + case BTF_FUNC_EXTERN: + return "extern"; + default: + return "(unknown)"; + } +} + +static const char *btf_str(const struct btf *btf, __u32 off) +{ + if (!off) + return "(anon)"; + return btf__str_by_offset(btf, off) ?: "(invalid)"; +} + +int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id) +{ + const struct btf_type *t; + int kind, i; + __u32 vlen; + + t = btf__type_by_id(btf, id); + if (!t) + return -EINVAL; + + vlen = btf_vlen(t); + kind = btf_kind(t); + + fprintf(out, "[%u] %s '%s'", id, btf_kind_str(kind), btf_str(btf, t->name_off)); + + switch (kind) { + case BTF_KIND_INT: + fprintf(out, " size=%u bits_offset=%u nr_bits=%u encoding=%s", + t->size, btf_int_offset(t), btf_int_bits(t), + btf_int_enc_str(btf_int_encoding(t))); + break; + case BTF_KIND_PTR: + case BTF_KIND_CONST: + case BTF_KIND_VOLATILE: + case BTF_KIND_RESTRICT: + case BTF_KIND_TYPEDEF: + fprintf(out, " type_id=%u", t->type); + break; + case BTF_KIND_ARRAY: { + const struct btf_array *arr = btf_array(t); + + fprintf(out, " type_id=%u index_type_id=%u nr_elems=%u", + arr->type, arr->index_type, arr->nelems); + break; + } + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: { + const struct btf_member *m = btf_members(t); + + fprintf(out, " size=%u vlen=%u", t->size, vlen); + for (i = 0; i < vlen; i++, m++) { + __u32 bit_off, bit_sz; + + bit_off = btf_member_bit_offset(t, i); + bit_sz = btf_member_bitfield_size(t, i); + fprintf(out, "\n\t'%s' type_id=%u bits_offset=%u", + btf_str(btf, m->name_off), m->type, bit_off); + if (bit_sz) + fprintf(out, " bitfield_size=%u", bit_sz); + } + break; + } + case BTF_KIND_ENUM: { + const struct btf_enum *v = btf_enum(t); + + fprintf(out, " size=%u vlen=%u", t->size, vlen); + for (i = 0; i < vlen; i++, v++) { + fprintf(out, "\n\t'%s' val=%u", + btf_str(btf, v->name_off), v->val); + } + break; + } + case BTF_KIND_FWD: + fprintf(out, " fwd_kind=%s", btf_kflag(t) ? "union" : "struct"); + break; + case BTF_KIND_FUNC: + fprintf(out, " type_id=%u linkage=%s", t->type, btf_func_linkage_str(t)); + break; + case BTF_KIND_FUNC_PROTO: { + const struct btf_param *p = btf_params(t); + + fprintf(out, " ret_type_id=%u vlen=%u", t->type, vlen); + for (i = 0; i < vlen; i++, p++) { + fprintf(out, "\n\t'%s' type_id=%u", + btf_str(btf, p->name_off), p->type); + } + break; + } + case BTF_KIND_VAR: + fprintf(out, " type_id=%u, linkage=%s", + t->type, btf_var_linkage_str(btf_var(t)->linkage)); + break; + case BTF_KIND_DATASEC: { + const struct btf_var_secinfo *v = btf_var_secinfos(t); + + fprintf(out, " size=%u vlen=%u", t->size, vlen); + for (i = 0; i < vlen; i++, v++) { + fprintf(out, "\n\ttype_id=%u offset=%u size=%u", + v->type, v->offset, v->size); + } + break; + } + default: + break; + } + + return 0; +} + +/* Print raw BTF type dump into a local buffer and return string pointer back. + * Buffer *will* be overwritten by subsequent btf_type_raw_dump() calls + */ +const char *btf_type_raw_dump(const struct btf *btf, int type_id) +{ + static char buf[16 * 1024]; + FILE *buf_file; + + buf_file = fmemopen(buf, sizeof(buf) - 1, "w"); + if (!buf_file) { + fprintf(stderr, "Failed to open memstream: %d\n", errno); + return NULL; + } + + fprintf_btf_type_raw(buf_file, btf, type_id); + fflush(buf_file); + fclose(buf_file); + + return buf; +} diff --git a/tools/testing/selftests/bpf/btf_helpers.h b/tools/testing/selftests/bpf/btf_helpers.h new file mode 100644 index 000000000000..2c9ce1b61dc9 --- /dev/null +++ b/tools/testing/selftests/bpf/btf_helpers.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2020 Facebook */ +#ifndef __BTF_HELPERS_H +#define __BTF_HELPERS_H + +#include <stdio.h> +#include <bpf/btf.h> + +int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id); +const char *btf_type_raw_dump(const struct btf *btf, int type_id); + +#endif diff --git a/tools/testing/selftests/bpf/prog_tests/btf_write.c b/tools/testing/selftests/bpf/prog_tests/btf_write.c index 314e1e7c36df..f36da15b134f 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_write.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_write.c @@ -2,6 +2,7 @@ /* Copyright (c) 2020 Facebook */ #include <test_progs.h> #include <bpf/btf.h> +#include "btf_helpers.h"
static int duration = 0;
@@ -39,6 +40,8 @@ void test_btf_write() { ASSERT_EQ(t->size, 4, "int_sz"); ASSERT_EQ(btf_int_encoding(t), BTF_INT_SIGNED, "int_enc"); ASSERT_EQ(btf_int_bits(t), 32, "int_bits"); + ASSERT_STREQ(btf_type_raw_dump(btf, 1), + "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED", "raw_dump");
/* invalid int size */ id = btf__add_int(btf, "bad sz int", 7, 0); @@ -59,24 +62,32 @@ void test_btf_write() { t = btf__type_by_id(btf, 2); ASSERT_EQ(btf_kind(t), BTF_KIND_PTR, "ptr_kind"); ASSERT_EQ(t->type, 1, "ptr_type"); + ASSERT_STREQ(btf_type_raw_dump(btf, 2), + "[2] PTR '(anon)' type_id=1", "raw_dump");
id = btf__add_const(btf, 5); /* points forward to restrict */ ASSERT_EQ(id, 3, "const_id"); t = btf__type_by_id(btf, 3); ASSERT_EQ(btf_kind(t), BTF_KIND_CONST, "const_kind"); ASSERT_EQ(t->type, 5, "const_type"); + ASSERT_STREQ(btf_type_raw_dump(btf, 3), + "[3] CONST '(anon)' type_id=5", "raw_dump");
id = btf__add_volatile(btf, 3); ASSERT_EQ(id, 4, "volatile_id"); t = btf__type_by_id(btf, 4); ASSERT_EQ(btf_kind(t), BTF_KIND_VOLATILE, "volatile_kind"); ASSERT_EQ(t->type, 3, "volatile_type"); + ASSERT_STREQ(btf_type_raw_dump(btf, 4), + "[4] VOLATILE '(anon)' type_id=3", "raw_dump");
id = btf__add_restrict(btf, 4); ASSERT_EQ(id, 5, "restrict_id"); t = btf__type_by_id(btf, 5); ASSERT_EQ(btf_kind(t), BTF_KIND_RESTRICT, "restrict_kind"); ASSERT_EQ(t->type, 4, "restrict_type"); + ASSERT_STREQ(btf_type_raw_dump(btf, 5), + "[5] RESTRICT '(anon)' type_id=4", "raw_dump");
/* ARRAY */ id = btf__add_array(btf, 1, 2, 10); /* int *[10] */ @@ -86,6 +97,8 @@ void test_btf_write() { ASSERT_EQ(btf_array(t)->index_type, 1, "array_index_type"); ASSERT_EQ(btf_array(t)->type, 2, "array_elem_type"); ASSERT_EQ(btf_array(t)->nelems, 10, "array_nelems"); + ASSERT_STREQ(btf_type_raw_dump(btf, 6), + "[6] ARRAY '(anon)' type_id=2 index_type_id=1 nr_elems=10", "raw_dump");
/* STRUCT */ err = btf__add_field(btf, "field", 1, 0, 0); @@ -113,6 +126,10 @@ void test_btf_write() { ASSERT_EQ(m->type, 1, "f2_type"); ASSERT_EQ(btf_member_bit_offset(t, 1), 32, "f2_bit_off"); ASSERT_EQ(btf_member_bitfield_size(t, 1), 16, "f2_bit_sz"); + ASSERT_STREQ(btf_type_raw_dump(btf, 7), + "[7] STRUCT 's1' size=8 vlen=2\n" + "\t'f1' type_id=1 bits_offset=0\n" + "\t'f2' type_id=1 bits_offset=32 bitfield_size=16", "raw_dump");
/* UNION */ id = btf__add_union(btf, "u1", 8); @@ -136,6 +153,9 @@ void test_btf_write() { ASSERT_EQ(m->type, 1, "f1_type"); ASSERT_EQ(btf_member_bit_offset(t, 0), 0, "f1_bit_off"); ASSERT_EQ(btf_member_bitfield_size(t, 0), 16, "f1_bit_sz"); + ASSERT_STREQ(btf_type_raw_dump(btf, 8), + "[8] UNION 'u1' size=8 vlen=1\n" + "\t'f1' type_id=1 bits_offset=0 bitfield_size=16", "raw_dump");
/* ENUM */ id = btf__add_enum(btf, "e1", 4); @@ -156,6 +176,10 @@ void test_btf_write() { v = btf_enum(t) + 1; ASSERT_STREQ(btf__str_by_offset(btf, v->name_off), "v2", "v2_name"); ASSERT_EQ(v->val, 2, "v2_val"); + ASSERT_STREQ(btf_type_raw_dump(btf, 9), + "[9] ENUM 'e1' size=4 vlen=2\n" + "\t'v1' val=1\n" + "\t'v2' val=2", "raw_dump");
/* FWDs */ id = btf__add_fwd(btf, "struct_fwd", BTF_FWD_STRUCT); @@ -164,6 +188,8 @@ void test_btf_write() { ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "struct_fwd", "fwd_name"); ASSERT_EQ(btf_kind(t), BTF_KIND_FWD, "fwd_kind"); ASSERT_EQ(btf_kflag(t), 0, "fwd_kflag"); + ASSERT_STREQ(btf_type_raw_dump(btf, 10), + "[10] FWD 'struct_fwd' fwd_kind=struct", "raw_dump");
id = btf__add_fwd(btf, "union_fwd", BTF_FWD_UNION); ASSERT_EQ(id, 11, "union_fwd_id"); @@ -171,6 +197,8 @@ void test_btf_write() { ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "union_fwd", "fwd_name"); ASSERT_EQ(btf_kind(t), BTF_KIND_FWD, "fwd_kind"); ASSERT_EQ(btf_kflag(t), 1, "fwd_kflag"); + ASSERT_STREQ(btf_type_raw_dump(btf, 11), + "[11] FWD 'union_fwd' fwd_kind=union", "raw_dump");
id = btf__add_fwd(btf, "enum_fwd", BTF_FWD_ENUM); ASSERT_EQ(id, 12, "enum_fwd_id"); @@ -179,6 +207,8 @@ void test_btf_write() { ASSERT_EQ(btf_kind(t), BTF_KIND_ENUM, "enum_fwd_kind"); ASSERT_EQ(btf_vlen(t), 0, "enum_fwd_kind"); ASSERT_EQ(t->size, 4, "enum_fwd_sz"); + ASSERT_STREQ(btf_type_raw_dump(btf, 12), + "[12] ENUM 'enum_fwd' size=4 vlen=0", "raw_dump");
/* TYPEDEF */ id = btf__add_typedef(btf, "typedef1", 1); @@ -187,6 +217,8 @@ void test_btf_write() { ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "typedef1", "typedef_name"); ASSERT_EQ(btf_kind(t), BTF_KIND_TYPEDEF, "typedef_kind"); ASSERT_EQ(t->type, 1, "typedef_type"); + ASSERT_STREQ(btf_type_raw_dump(btf, 13), + "[13] TYPEDEF 'typedef1' type_id=1", "raw_dump");
/* FUNC & FUNC_PROTO */ id = btf__add_func(btf, "func1", BTF_FUNC_GLOBAL, 15); @@ -196,6 +228,8 @@ void test_btf_write() { ASSERT_EQ(t->type, 15, "func_type"); ASSERT_EQ(btf_kind(t), BTF_KIND_FUNC, "func_kind"); ASSERT_EQ(btf_vlen(t), BTF_FUNC_GLOBAL, "func_vlen"); + ASSERT_STREQ(btf_type_raw_dump(btf, 14), + "[14] FUNC 'func1' type_id=15 linkage=global", "raw_dump");
id = btf__add_func_proto(btf, 1); ASSERT_EQ(id, 15, "func_proto_id"); @@ -214,6 +248,10 @@ void test_btf_write() { p = btf_params(t) + 1; ASSERT_STREQ(btf__str_by_offset(btf, p->name_off), "p2", "p2_name"); ASSERT_EQ(p->type, 2, "p2_type"); + ASSERT_STREQ(btf_type_raw_dump(btf, 15), + "[15] FUNC_PROTO '(anon)' ret_type_id=1 vlen=2\n" + "\t'p1' type_id=1\n" + "\t'p2' type_id=2", "raw_dump");
/* VAR */ id = btf__add_var(btf, "var1", BTF_VAR_GLOBAL_ALLOCATED, 1); @@ -223,6 +261,8 @@ void test_btf_write() { ASSERT_EQ(btf_kind(t), BTF_KIND_VAR, "var_kind"); ASSERT_EQ(t->type, 1, "var_type"); ASSERT_EQ(btf_var(t)->linkage, BTF_VAR_GLOBAL_ALLOCATED, "var_type"); + ASSERT_STREQ(btf_type_raw_dump(btf, 16), + "[16] VAR 'var1' type_id=1, linkage=global-alloc", "raw_dump");
/* DATASECT */ id = btf__add_datasec(btf, "datasec1", 12); @@ -239,6 +279,9 @@ void test_btf_write() { ASSERT_EQ(vi->type, 1, "v1_type"); ASSERT_EQ(vi->offset, 4, "v1_off"); ASSERT_EQ(vi->size, 8, "v1_sz"); + ASSERT_STREQ(btf_type_raw_dump(btf, 17), + "[17] DATASEC 'datasec1' size=12 vlen=1\n" + "\ttype_id=1 offset=4 size=8", "raw_dump");
btf__free(btf); }