From b47a0bd23e34022aa0d4b812fcebe85cb0c54d49 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Mon, 19 Nov 2018 15:29:06 -0800 Subject: [PATCH 01/13] bpf: btf: Break up btf_type_is_void() This patch breaks up btf_type_is_void() into btf_type_is_void() and btf_type_is_fwd(). It also adds btf_type_nosize() to better describe it is testing a type has nosize info. Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- kernel/bpf/btf.c | 37 ++++++++++++++++++++++--------------- 1 file changed, 22 insertions(+), 15 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index ee4c82667d65..2a50d87de485 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -306,15 +306,22 @@ static bool btf_type_is_modifier(const struct btf_type *t) static bool btf_type_is_void(const struct btf_type *t) { - /* void => no type and size info. - * Hence, FWD is also treated as void. - */ - return t == &btf_void || BTF_INFO_KIND(t->info) == BTF_KIND_FWD; + return t == &btf_void; } -static bool btf_type_is_void_or_null(const struct btf_type *t) +static bool btf_type_is_fwd(const struct btf_type *t) { - return !t || btf_type_is_void(t); + return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; +} + +static bool btf_type_nosize(const struct btf_type *t) +{ + return btf_type_is_void(t) || btf_type_is_fwd(t); +} + +static bool btf_type_nosize_or_null(const struct btf_type *t) +{ + return !t || btf_type_nosize(t); } /* union is only a special case of struct: @@ -826,7 +833,7 @@ const struct btf_type *btf_type_id_size(const struct btf *btf, u32 size = 0; size_type = btf_type_by_id(btf, size_type_id); - if (btf_type_is_void_or_null(size_type)) + if (btf_type_nosize_or_null(size_type)) return NULL; if (btf_type_has_size(size_type)) { @@ -842,7 +849,7 @@ const struct btf_type *btf_type_id_size(const struct btf *btf, size = btf->resolved_sizes[size_type_id]; size_type_id = btf->resolved_ids[size_type_id]; size_type = btf_type_by_id(btf, size_type_id); - if (btf_type_is_void(size_type)) + if (btf_type_nosize_or_null(size_type)) return NULL; } @@ -1164,7 +1171,7 @@ static int btf_modifier_resolve(struct btf_verifier_env *env, } /* "typedef void new_void", "const void"...etc */ - if (btf_type_is_void(next_type)) + if (btf_type_is_void(next_type) || btf_type_is_fwd(next_type)) goto resolved; if (!env_type_is_resolve_sink(env, next_type) && @@ -1178,7 +1185,7 @@ static int btf_modifier_resolve(struct btf_verifier_env *env, * pretty print). */ if (!btf_type_id_size(btf, &next_type_id, &next_type_size) && - !btf_type_is_void(btf_type_id_resolve(btf, &next_type_id))) { + !btf_type_nosize(btf_type_id_resolve(btf, &next_type_id))) { btf_verifier_log_type(env, v->t, "Invalid type_id"); return -EINVAL; } @@ -1205,7 +1212,7 @@ static int btf_ptr_resolve(struct btf_verifier_env *env, } /* "void *" */ - if (btf_type_is_void(next_type)) + if (btf_type_is_void(next_type) || btf_type_is_fwd(next_type)) goto resolved; if (!env_type_is_resolve_sink(env, next_type) && @@ -1235,7 +1242,7 @@ static int btf_ptr_resolve(struct btf_verifier_env *env, } if (!btf_type_id_size(btf, &next_type_id, &next_type_size) && - !btf_type_is_void(btf_type_id_resolve(btf, &next_type_id))) { + !btf_type_nosize(btf_type_id_resolve(btf, &next_type_id))) { btf_verifier_log_type(env, v->t, "Invalid type_id"); return -EINVAL; } @@ -1396,7 +1403,7 @@ static int btf_array_resolve(struct btf_verifier_env *env, /* Check array->index_type */ index_type_id = array->index_type; index_type = btf_type_by_id(btf, index_type_id); - if (btf_type_is_void_or_null(index_type)) { + if (btf_type_nosize_or_null(index_type)) { btf_verifier_log_type(env, v->t, "Invalid index"); return -EINVAL; } @@ -1415,7 +1422,7 @@ static int btf_array_resolve(struct btf_verifier_env *env, /* Check array->type */ elem_type_id = array->type; elem_type = btf_type_by_id(btf, elem_type_id); - if (btf_type_is_void_or_null(elem_type)) { + if (btf_type_nosize_or_null(elem_type)) { btf_verifier_log_type(env, v->t, "Invalid elem"); return -EINVAL; @@ -1615,7 +1622,7 @@ static int btf_struct_resolve(struct btf_verifier_env *env, const struct btf_type *member_type = btf_type_by_id(env->btf, member_type_id); - if (btf_type_is_void_or_null(member_type)) { + if (btf_type_nosize_or_null(member_type)) { btf_verifier_log_member(env, v->t, member, "Invalid member"); return -EINVAL; From 2667a2626f4da370409c2830552f6e8c8b8c41e2 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Mon, 19 Nov 2018 15:29:08 -0800 Subject: [PATCH 02/13] bpf: btf: Add BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO This patch adds BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO to support the function debug info. BTF_KIND_FUNC_PROTO must not have a name (i.e. !t->name_off) and it is followed by >= 0 'struct bpf_param' objects to describe the function arguments. The BTF_KIND_FUNC must have a valid name and it must refer back to a BTF_KIND_FUNC_PROTO. The above is the conclusion after the discussion between Edward Cree, Alexei, Daniel, Yonghong and Martin. By combining BTF_KIND_FUNC and BTF_LIND_FUNC_PROTO, a complete function signature can be obtained. It will be used in the later patches to learn the function signature of a running bpf program. Signed-off-by: Martin KaFai Lau Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- include/uapi/linux/btf.h | 18 +- kernel/bpf/btf.c | 389 ++++++++++++++++++++++++++++++++++----- 2 files changed, 354 insertions(+), 53 deletions(-) diff --git a/include/uapi/linux/btf.h b/include/uapi/linux/btf.h index 972265f32871..14f66948fc95 100644 --- a/include/uapi/linux/btf.h +++ b/include/uapi/linux/btf.h @@ -40,7 +40,8 @@ struct btf_type { /* "size" is used by INT, ENUM, STRUCT and UNION. * "size" tells the size of the type it is describing. * - * "type" is used by PTR, TYPEDEF, VOLATILE, CONST and RESTRICT. + * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT, + * FUNC and FUNC_PROTO. * "type" is a type_id referring to another type. */ union { @@ -64,8 +65,10 @@ struct btf_type { #define BTF_KIND_VOLATILE 9 /* Volatile */ #define BTF_KIND_CONST 10 /* Const */ #define BTF_KIND_RESTRICT 11 /* Restrict */ -#define BTF_KIND_MAX 11 -#define NR_BTF_KINDS 12 +#define BTF_KIND_FUNC 12 /* Function */ +#define BTF_KIND_FUNC_PROTO 13 /* Function Proto */ +#define BTF_KIND_MAX 13 +#define NR_BTF_KINDS 14 /* For some specific BTF_KIND, "struct btf_type" is immediately * followed by extra data. @@ -110,4 +113,13 @@ struct btf_member { __u32 offset; /* offset in bits */ }; +/* BTF_KIND_FUNC_PROTO is followed by multiple "struct btf_param". + * The exact number of btf_param is stored in the vlen (of the + * info in "struct btf_type"). + */ +struct btf_param { + __u32 name_off; + __u32 type; +}; + #endif /* _UAPI__LINUX_BTF_H__ */ diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 2a50d87de485..6a2be79b73fc 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -5,6 +5,7 @@ #include #include #include +#include #include #include #include @@ -259,6 +260,8 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = { [BTF_KIND_VOLATILE] = "VOLATILE", [BTF_KIND_CONST] = "CONST", [BTF_KIND_RESTRICT] = "RESTRICT", + [BTF_KIND_FUNC] = "FUNC", + [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", }; struct btf_kind_operations { @@ -281,6 +284,9 @@ struct btf_kind_operations { static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS]; static struct btf_type btf_void; +static int btf_resolve(struct btf_verifier_env *env, + const struct btf_type *t, u32 type_id); + static bool btf_type_is_modifier(const struct btf_type *t) { /* Some of them is not strictly a C modifier @@ -314,9 +320,20 @@ static bool btf_type_is_fwd(const struct btf_type *t) return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; } +static bool btf_type_is_func(const struct btf_type *t) +{ + return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC; +} + +static bool btf_type_is_func_proto(const struct btf_type *t) +{ + return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO; +} + static bool btf_type_nosize(const struct btf_type *t) { - return btf_type_is_void(t) || btf_type_is_fwd(t); + return btf_type_is_void(t) || btf_type_is_fwd(t) || + btf_type_is_func(t) || btf_type_is_func_proto(t); } static bool btf_type_nosize_or_null(const struct btf_type *t) @@ -433,6 +450,30 @@ static bool btf_name_offset_valid(const struct btf *btf, u32 offset) offset < btf->hdr.str_len; } +/* Only C-style identifier is permitted. This can be relaxed if + * necessary. + */ +static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) +{ + /* offset must be valid */ + const char *src = &btf->strings[offset]; + const char *src_limit; + + if (!isalpha(*src) && *src != '_') + return false; + + /* set a limit on identifier length */ + src_limit = src + KSYM_NAME_LEN; + src++; + while (*src && src < src_limit) { + if (!isalnum(*src) && *src != '_') + return false; + src++; + } + + return !*src; +} + static const char *btf_name_by_offset(const struct btf *btf, u32 offset) { if (!offset) @@ -747,11 +788,15 @@ static bool env_type_is_resolve_sink(const struct btf_verifier_env *env, /* int, enum or void is a sink */ return !btf_type_needs_resolve(next_type); case RESOLVE_PTR: - /* int, enum, void, struct or array is a sink for ptr */ + /* int, enum, void, struct, array, func or func_proto is a sink + * for ptr + */ return !btf_type_is_modifier(next_type) && !btf_type_is_ptr(next_type); case RESOLVE_STRUCT_OR_ARRAY: - /* int, enum, void or ptr is a sink for struct and array */ + /* int, enum, void, ptr, func or func_proto is a sink + * for struct and array + */ return !btf_type_is_modifier(next_type) && !btf_type_is_array(next_type) && !btf_type_is_struct(next_type); @@ -1170,10 +1215,6 @@ static int btf_modifier_resolve(struct btf_verifier_env *env, return -EINVAL; } - /* "typedef void new_void", "const void"...etc */ - if (btf_type_is_void(next_type) || btf_type_is_fwd(next_type)) - goto resolved; - if (!env_type_is_resolve_sink(env, next_type) && !env_type_is_resolved(env, next_type_id)) return env_stack_push(env, next_type, next_type_id); @@ -1184,13 +1225,18 @@ static int btf_modifier_resolve(struct btf_verifier_env *env, * save us a few type-following when we use it later (e.g. in * pretty print). */ - if (!btf_type_id_size(btf, &next_type_id, &next_type_size) && - !btf_type_nosize(btf_type_id_resolve(btf, &next_type_id))) { - btf_verifier_log_type(env, v->t, "Invalid type_id"); - return -EINVAL; + if (!btf_type_id_size(btf, &next_type_id, &next_type_size)) { + if (env_type_is_resolved(env, next_type_id)) + next_type = btf_type_id_resolve(btf, &next_type_id); + + /* "typedef void new_void", "const void"...etc */ + if (!btf_type_is_void(next_type) && + !btf_type_is_fwd(next_type)) { + btf_verifier_log_type(env, v->t, "Invalid type_id"); + return -EINVAL; + } } -resolved: env_stack_pop_resolved(env, next_type_id, next_type_size); return 0; @@ -1203,7 +1249,6 @@ static int btf_ptr_resolve(struct btf_verifier_env *env, const struct btf_type *t = v->t; u32 next_type_id = t->type; struct btf *btf = env->btf; - u32 next_type_size = 0; next_type = btf_type_by_id(btf, next_type_id); if (!next_type) { @@ -1211,10 +1256,6 @@ static int btf_ptr_resolve(struct btf_verifier_env *env, return -EINVAL; } - /* "void *" */ - if (btf_type_is_void(next_type) || btf_type_is_fwd(next_type)) - goto resolved; - if (!env_type_is_resolve_sink(env, next_type) && !env_type_is_resolved(env, next_type_id)) return env_stack_push(env, next_type, next_type_id); @@ -1241,13 +1282,18 @@ static int btf_ptr_resolve(struct btf_verifier_env *env, resolved_type_id); } - if (!btf_type_id_size(btf, &next_type_id, &next_type_size) && - !btf_type_nosize(btf_type_id_resolve(btf, &next_type_id))) { - btf_verifier_log_type(env, v->t, "Invalid type_id"); - return -EINVAL; + if (!btf_type_id_size(btf, &next_type_id, NULL)) { + if (env_type_is_resolved(env, next_type_id)) + next_type = btf_type_id_resolve(btf, &next_type_id); + + if (!btf_type_is_void(next_type) && + !btf_type_is_fwd(next_type) && + !btf_type_is_func_proto(next_type)) { + btf_verifier_log_type(env, v->t, "Invalid type_id"); + return -EINVAL; + } } -resolved: env_stack_pop_resolved(env, next_type_id, 0); return 0; @@ -1787,6 +1833,232 @@ static struct btf_kind_operations enum_ops = { .seq_show = btf_enum_seq_show, }; +static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, + const struct btf_type *t, + u32 meta_left) +{ + u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param); + + if (meta_left < meta_needed) { + btf_verifier_log_basic(env, t, + "meta_left:%u meta_needed:%u", + meta_left, meta_needed); + return -EINVAL; + } + + if (t->name_off) { + btf_verifier_log_type(env, t, "Invalid name"); + return -EINVAL; + } + + btf_verifier_log_type(env, t, NULL); + + return meta_needed; +} + +static void btf_func_proto_log(struct btf_verifier_env *env, + const struct btf_type *t) +{ + const struct btf_param *args = (const struct btf_param *)(t + 1); + u16 nr_args = btf_type_vlen(t), i; + + btf_verifier_log(env, "return=%u args=(", t->type); + if (!nr_args) { + btf_verifier_log(env, "void"); + goto done; + } + + if (nr_args == 1 && !args[0].type) { + /* Only one vararg */ + btf_verifier_log(env, "vararg"); + goto done; + } + + btf_verifier_log(env, "%u %s", args[0].type, + btf_name_by_offset(env->btf, + args[0].name_off)); + for (i = 1; i < nr_args - 1; i++) + btf_verifier_log(env, ", %u %s", args[i].type, + btf_name_by_offset(env->btf, + args[i].name_off)); + + if (nr_args > 1) { + const struct btf_param *last_arg = &args[nr_args - 1]; + + if (last_arg->type) + btf_verifier_log(env, ", %u %s", last_arg->type, + btf_name_by_offset(env->btf, + last_arg->name_off)); + else + btf_verifier_log(env, ", vararg"); + } + +done: + btf_verifier_log(env, ")"); +} + +static struct btf_kind_operations func_proto_ops = { + .check_meta = btf_func_proto_check_meta, + .resolve = btf_df_resolve, + /* + * BTF_KIND_FUNC_PROTO cannot be directly referred by + * a struct's member. + * + * It should be a funciton pointer instead. + * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO) + * + * Hence, there is no btf_func_check_member(). + */ + .check_member = btf_df_check_member, + .log_details = btf_func_proto_log, + .seq_show = btf_df_seq_show, +}; + +static s32 btf_func_check_meta(struct btf_verifier_env *env, + const struct btf_type *t, + u32 meta_left) +{ + if (!t->name_off || + !btf_name_valid_identifier(env->btf, t->name_off)) { + btf_verifier_log_type(env, t, "Invalid name"); + return -EINVAL; + } + + if (btf_type_vlen(t)) { + btf_verifier_log_type(env, t, "vlen != 0"); + return -EINVAL; + } + + btf_verifier_log_type(env, t, NULL); + + return 0; +} + +static struct btf_kind_operations func_ops = { + .check_meta = btf_func_check_meta, + .resolve = btf_df_resolve, + .check_member = btf_df_check_member, + .log_details = btf_ref_type_log, + .seq_show = btf_df_seq_show, +}; + +static int btf_func_proto_check(struct btf_verifier_env *env, + const struct btf_type *t) +{ + const struct btf_type *ret_type; + const struct btf_param *args; + const struct btf *btf; + u16 nr_args, i; + int err; + + btf = env->btf; + args = (const struct btf_param *)(t + 1); + nr_args = btf_type_vlen(t); + + /* Check func return type which could be "void" (t->type == 0) */ + if (t->type) { + u32 ret_type_id = t->type; + + ret_type = btf_type_by_id(btf, ret_type_id); + if (!ret_type) { + btf_verifier_log_type(env, t, "Invalid return type"); + return -EINVAL; + } + + if (btf_type_needs_resolve(ret_type) && + !env_type_is_resolved(env, ret_type_id)) { + err = btf_resolve(env, ret_type, ret_type_id); + if (err) + return err; + } + + /* Ensure the return type is a type that has a size */ + if (!btf_type_id_size(btf, &ret_type_id, NULL)) { + btf_verifier_log_type(env, t, "Invalid return type"); + return -EINVAL; + } + } + + if (!nr_args) + return 0; + + /* Last func arg type_id could be 0 if it is a vararg */ + if (!args[nr_args - 1].type) { + if (args[nr_args - 1].name_off) { + btf_verifier_log_type(env, t, "Invalid arg#%u", + nr_args); + return -EINVAL; + } + nr_args--; + } + + err = 0; + for (i = 0; i < nr_args; i++) { + const struct btf_type *arg_type; + u32 arg_type_id; + + arg_type_id = args[i].type; + arg_type = btf_type_by_id(btf, arg_type_id); + if (!arg_type) { + btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); + err = -EINVAL; + break; + } + + if (args[i].name_off && + (!btf_name_offset_valid(btf, args[i].name_off) || + !btf_name_valid_identifier(btf, args[i].name_off))) { + btf_verifier_log_type(env, t, + "Invalid arg#%u", i + 1); + err = -EINVAL; + break; + } + + if (btf_type_needs_resolve(arg_type) && + !env_type_is_resolved(env, arg_type_id)) { + err = btf_resolve(env, arg_type, arg_type_id); + if (err) + break; + } + + if (!btf_type_id_size(btf, &arg_type_id, NULL)) { + btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); + err = -EINVAL; + break; + } + } + + return err; +} + +static int btf_func_check(struct btf_verifier_env *env, + const struct btf_type *t) +{ + const struct btf_type *proto_type; + const struct btf_param *args; + const struct btf *btf; + u16 nr_args, i; + + btf = env->btf; + proto_type = btf_type_by_id(btf, t->type); + + if (!proto_type || !btf_type_is_func_proto(proto_type)) { + btf_verifier_log_type(env, t, "Invalid type_id"); + return -EINVAL; + } + + args = (const struct btf_param *)(proto_type + 1); + nr_args = btf_type_vlen(proto_type); + for (i = 0; i < nr_args; i++) { + if (!args[i].name_off && args[i].type) { + btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); + return -EINVAL; + } + } + + return 0; +} + static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { [BTF_KIND_INT] = &int_ops, [BTF_KIND_PTR] = &ptr_ops, @@ -1799,6 +2071,8 @@ static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { [BTF_KIND_VOLATILE] = &modifier_ops, [BTF_KIND_CONST] = &modifier_ops, [BTF_KIND_RESTRICT] = &modifier_ops, + [BTF_KIND_FUNC] = &func_ops, + [BTF_KIND_FUNC_PROTO] = &func_proto_ops, }; static s32 btf_check_meta(struct btf_verifier_env *env, @@ -1870,30 +2144,6 @@ static int btf_check_all_metas(struct btf_verifier_env *env) return 0; } -static int btf_resolve(struct btf_verifier_env *env, - const struct btf_type *t, u32 type_id) -{ - const struct resolve_vertex *v; - int err = 0; - - env->resolve_mode = RESOLVE_TBD; - env_stack_push(env, t, type_id); - while (!err && (v = env_stack_peak(env))) { - env->log_type_id = v->type_id; - err = btf_type_ops(v->t)->resolve(env, v); - } - - env->log_type_id = type_id; - if (err == -E2BIG) - btf_verifier_log_type(env, t, - "Exceeded max resolving depth:%u", - MAX_RESOLVE_DEPTH); - else if (err == -EEXIST) - btf_verifier_log_type(env, t, "Loop detected"); - - return err; -} - static bool btf_resolve_valid(struct btf_verifier_env *env, const struct btf_type *t, u32 type_id) @@ -1927,6 +2177,39 @@ static bool btf_resolve_valid(struct btf_verifier_env *env, return false; } +static int btf_resolve(struct btf_verifier_env *env, + const struct btf_type *t, u32 type_id) +{ + u32 save_log_type_id = env->log_type_id; + const struct resolve_vertex *v; + int err = 0; + + env->resolve_mode = RESOLVE_TBD; + env_stack_push(env, t, type_id); + while (!err && (v = env_stack_peak(env))) { + env->log_type_id = v->type_id; + err = btf_type_ops(v->t)->resolve(env, v); + } + + env->log_type_id = type_id; + if (err == -E2BIG) { + btf_verifier_log_type(env, t, + "Exceeded max resolving depth:%u", + MAX_RESOLVE_DEPTH); + } else if (err == -EEXIST) { + btf_verifier_log_type(env, t, "Loop detected"); + } + + /* Final sanity check */ + if (!err && !btf_resolve_valid(env, t, type_id)) { + btf_verifier_log_type(env, t, "Invalid resolve state"); + err = -EINVAL; + } + + env->log_type_id = save_log_type_id; + return err; +} + static int btf_check_all_types(struct btf_verifier_env *env) { struct btf *btf = env->btf; @@ -1949,10 +2232,16 @@ static int btf_check_all_types(struct btf_verifier_env *env) return err; } - if (btf_type_needs_resolve(t) && - !btf_resolve_valid(env, t, type_id)) { - btf_verifier_log_type(env, t, "Invalid resolve state"); - return -EINVAL; + if (btf_type_is_func_proto(t)) { + err = btf_func_proto_check(env, t); + if (err) + return err; + } + + if (btf_type_is_func(t)) { + err = btf_func_check(env, t); + if (err) + return err; } } From 781e775e296ce3aabe0a4a0f773dccda02267695 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Mon, 19 Nov 2018 15:29:09 -0800 Subject: [PATCH 03/13] tools/bpf: Sync kernel btf.h header The kernel uapi btf.h is synced to the tools directory. Signed-off-by: Martin KaFai Lau Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- tools/include/uapi/linux/btf.h | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/tools/include/uapi/linux/btf.h b/tools/include/uapi/linux/btf.h index 972265f32871..14f66948fc95 100644 --- a/tools/include/uapi/linux/btf.h +++ b/tools/include/uapi/linux/btf.h @@ -40,7 +40,8 @@ struct btf_type { /* "size" is used by INT, ENUM, STRUCT and UNION. * "size" tells the size of the type it is describing. * - * "type" is used by PTR, TYPEDEF, VOLATILE, CONST and RESTRICT. + * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT, + * FUNC and FUNC_PROTO. * "type" is a type_id referring to another type. */ union { @@ -64,8 +65,10 @@ struct btf_type { #define BTF_KIND_VOLATILE 9 /* Volatile */ #define BTF_KIND_CONST 10 /* Const */ #define BTF_KIND_RESTRICT 11 /* Restrict */ -#define BTF_KIND_MAX 11 -#define NR_BTF_KINDS 12 +#define BTF_KIND_FUNC 12 /* Function */ +#define BTF_KIND_FUNC_PROTO 13 /* Function Proto */ +#define BTF_KIND_MAX 13 +#define NR_BTF_KINDS 14 /* For some specific BTF_KIND, "struct btf_type" is immediately * followed by extra data. @@ -110,4 +113,13 @@ struct btf_member { __u32 offset; /* offset in bits */ }; +/* BTF_KIND_FUNC_PROTO is followed by multiple "struct btf_param". + * The exact number of btf_param is stored in the vlen (of the + * info in "struct btf_type"). + */ +struct btf_param { + __u32 name_off; + __u32 type; +}; + #endif /* _UAPI__LINUX_BTF_H__ */ From 78a2540e8945678b390a5f41eb82459bc6f0f36c Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Mon, 19 Nov 2018 15:29:10 -0800 Subject: [PATCH 04/13] tools/bpf: Add tests for BTF_KIND_FUNC_PROTO and BTF_KIND_FUNC This patch adds unit tests for BTF_KIND_FUNC_PROTO and BTF_KIND_FUNC to test_btf. Signed-off-by: Martin KaFai Lau Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/btf.c | 4 + tools/testing/selftests/bpf/test_btf.c | 474 ++++++++++++++++++++++++- 2 files changed, 476 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 449591aa9900..31225e64766f 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -165,6 +165,10 @@ static int btf_parse_type_sec(struct btf *btf, btf_print_fn_t err_log) case BTF_KIND_ENUM: next_type += vlen * sizeof(struct btf_enum); break; + case BTF_KIND_FUNC_PROTO: + next_type += vlen * sizeof(struct btf_param); + break; + case BTF_KIND_FUNC: case BTF_KIND_TYPEDEF: case BTF_KIND_PTR: case BTF_KIND_FWD: diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index f42b3396d622..e0eeee5c8c04 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -85,8 +85,20 @@ static int __base_pr(const char *format, ...) #define BTF_TYPEDEF_ENC(name, type) \ BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_TYPEDEF, 0, 0), type) -#define BTF_PTR_ENC(name, type) \ - BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), type) +#define BTF_PTR_ENC(type) \ + BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), type) + +#define BTF_CONST_ENC(type) \ + BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_CONST, 0, 0), type) + +#define BTF_FUNC_PROTO_ENC(ret_type, nargs) \ + BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, nargs), ret_type) + +#define BTF_FUNC_PROTO_ARG_ENC(name, type) \ + (name), (type) + +#define BTF_FUNC_ENC(name, func_proto) \ + BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0), func_proto) #define BTF_END_RAW 0xdeadbeef #define NAME_TBD 0xdeadb33f @@ -1374,6 +1386,464 @@ static struct btf_raw_test raw_tests[] = { .map_create_err = true, }, +{ + .descr = "func proto (int (*)(int, unsigned int))", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* int (*)(int, unsigned int) */ + BTF_FUNC_PROTO_ENC(1, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(0, 1), + BTF_FUNC_PROTO_ARG_ENC(0, 2), + BTF_END_RAW, + }, + .str_sec = "", + .str_sec_size = sizeof(""), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, +}, + +{ + .descr = "func proto (vararg)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void (*)(int, unsigned int, ...) */ + BTF_FUNC_PROTO_ENC(0, 3), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(0, 1), + BTF_FUNC_PROTO_ARG_ENC(0, 2), + BTF_FUNC_PROTO_ARG_ENC(0, 0), + BTF_END_RAW, + }, + .str_sec = "", + .str_sec_size = sizeof(""), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, +}, + +{ + .descr = "func proto (vararg with name)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void (*)(int a, unsigned int b, ... c) */ + BTF_FUNC_PROTO_ENC(0, 3), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 0), + BTF_END_RAW, + }, + .str_sec = "\0a\0b\0c", + .str_sec_size = sizeof("\0a\0b\0c"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "Invalid arg#3", +}, + +{ + .descr = "func proto (arg after vararg)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void (*)(int a, ..., unsigned int b) */ + BTF_FUNC_PROTO_ENC(0, 3), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(0, 0), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + BTF_END_RAW, + }, + .str_sec = "\0a\0b", + .str_sec_size = sizeof("\0a\0b"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "Invalid arg#2", +}, + +{ + .descr = "func proto (CONST=>TYPEDEF=>PTR=>FUNC_PROTO)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* typedef void (*func_ptr)(int, unsigned int) */ + BTF_TYPEDEF_ENC(NAME_TBD, 5), /* [3] */ + /* const func_ptr */ + BTF_CONST_ENC(3), /* [4] */ + BTF_PTR_ENC(6), /* [5] */ + BTF_FUNC_PROTO_ENC(0, 2), /* [6] */ + BTF_FUNC_PROTO_ARG_ENC(0, 1), + BTF_FUNC_PROTO_ARG_ENC(0, 2), + BTF_END_RAW, + }, + .str_sec = "\0func_ptr", + .str_sec_size = sizeof("\0func_ptr"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, +}, + +{ + .descr = "func proto (CONST=>TYPEDEF=>FUNC_PROTO)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + BTF_CONST_ENC(4), /* [3] */ + BTF_TYPEDEF_ENC(NAME_TBD, 5), /* [4] */ + BTF_FUNC_PROTO_ENC(0, 2), /* [5] */ + BTF_FUNC_PROTO_ARG_ENC(0, 1), + BTF_FUNC_PROTO_ARG_ENC(0, 2), + BTF_END_RAW, + }, + .str_sec = "\0func_typedef", + .str_sec_size = sizeof("\0func_typedef"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "Invalid type_id", +}, + +{ + .descr = "func proto (btf_resolve(arg))", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + /* void (*)(const void *) */ + BTF_FUNC_PROTO_ENC(0, 1), /* [2] */ + BTF_FUNC_PROTO_ARG_ENC(0, 3), + BTF_CONST_ENC(4), /* [3] */ + BTF_PTR_ENC(0), /* [4] */ + BTF_END_RAW, + }, + .str_sec = "", + .str_sec_size = sizeof(""), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, +}, + +{ + .descr = "func proto (Not all arg has name)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void (*)(int, unsigned int b) */ + BTF_FUNC_PROTO_ENC(0, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(0, 1), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + BTF_END_RAW, + }, + .str_sec = "\0b", + .str_sec_size = sizeof("\0b"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, +}, + +{ + .descr = "func proto (Bad arg name_off)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void (*)(int a, unsigned int ) */ + BTF_FUNC_PROTO_ENC(0, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(0xffffffff, 2), + BTF_END_RAW, + }, + .str_sec = "\0a", + .str_sec_size = sizeof("\0a"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "Invalid arg#2", +}, + +{ + .descr = "func proto (Bad arg name)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void (*)(int a, unsigned int !!!) */ + BTF_FUNC_PROTO_ENC(0, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + BTF_END_RAW, + }, + .str_sec = "\0a\0!!!", + .str_sec_size = sizeof("\0a\0!!!"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "Invalid arg#2", +}, + +{ + .descr = "func proto (Invalid return type)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* (*)(int, unsigned int) */ + BTF_FUNC_PROTO_ENC(100, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(0, 1), + BTF_FUNC_PROTO_ARG_ENC(0, 2), + BTF_END_RAW, + }, + .str_sec = "", + .str_sec_size = sizeof(""), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "Invalid return type", +}, + +{ + .descr = "func proto (with func name)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void func_proto(int, unsigned int) */ + BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 2), 0), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(0, 1), + BTF_FUNC_PROTO_ARG_ENC(0, 2), + BTF_END_RAW, + }, + .str_sec = "\0func_proto", + .str_sec_size = sizeof("\0func_proto"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "Invalid name", +}, + +{ + .descr = "func proto (const void arg)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void (*)(const void) */ + BTF_FUNC_PROTO_ENC(0, 1), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(0, 4), + BTF_CONST_ENC(0), /* [4] */ + BTF_END_RAW, + }, + .str_sec = "", + .str_sec_size = sizeof(""), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_proto_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "Invalid arg#1", +}, + +{ + .descr = "func (void func(int a, unsigned int b))", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void (*)(int a, unsigned int b) */ + BTF_FUNC_PROTO_ENC(0, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + /* void func(int a, unsigned int b) */ + BTF_FUNC_ENC(NAME_TBD, 3), /* [4] */ + BTF_END_RAW, + }, + .str_sec = "\0a\0b\0func", + .str_sec_size = sizeof("\0a\0b\0func"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, +}, + +{ + .descr = "func (No func name)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void (*)(int a, unsigned int b) */ + BTF_FUNC_PROTO_ENC(0, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + /* void (int a, unsigned int b) */ + BTF_FUNC_ENC(0, 3), /* [4] */ + BTF_END_RAW, + }, + .str_sec = "\0a\0b", + .str_sec_size = sizeof("\0a\0b"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "Invalid name", +}, + +{ + .descr = "func (Invalid func name)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void (*)(int a, unsigned int b) */ + BTF_FUNC_PROTO_ENC(0, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + /* void !!!(int a, unsigned int b) */ + BTF_FUNC_ENC(NAME_TBD, 3), /* [4] */ + BTF_END_RAW, + }, + .str_sec = "\0a\0b\0!!!", + .str_sec_size = sizeof("\0a\0b\0!!!"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "Invalid name", +}, + +{ + .descr = "func (Some arg has no name)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void (*)(int a, unsigned int) */ + BTF_FUNC_PROTO_ENC(0, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(0, 2), + /* void func(int a, unsigned int) */ + BTF_FUNC_ENC(NAME_TBD, 3), /* [4] */ + BTF_END_RAW, + }, + .str_sec = "\0a\0func", + .str_sec_size = sizeof("\0a\0func"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "Invalid arg#2", +}, + +{ + .descr = "func (Non zero vlen)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), /* [2] */ + /* void (*)(int a, unsigned int b) */ + BTF_FUNC_PROTO_ENC(0, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + /* void func(int a, unsigned int b) */ + BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_FUNC, 0, 2), 3), /* [4] */ + BTF_END_RAW, + }, + .str_sec = "\0a\0b\0func", + .str_sec_size = sizeof("\0a\0b\0func"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "vlen != 0", +}, + +{ + .descr = "func (Not referring to FUNC_PROTO)", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_FUNC_ENC(NAME_TBD, 1), /* [2] */ + BTF_END_RAW, + }, + .str_sec = "\0func", + .str_sec_size = sizeof("\0func"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "func_type_check_btf", + .key_size = sizeof(int), + .value_size = sizeof(int), + .key_type_id = 1, + .value_type_id = 1, + .max_entries = 4, + .btf_load_err = true, + .err_str = "Invalid type_id", +}, + }; /* struct btf_raw_test raw_tests[] */ static const char *get_next_str(const char *start, const char *end) From 838e96904ff3fc6c30e5ebbc611474669856e3c0 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 19 Nov 2018 15:29:11 -0800 Subject: [PATCH 05/13] bpf: Introduce bpf_func_info This patch added interface to load a program with the following additional information: . prog_btf_fd . func_info, func_info_rec_size and func_info_cnt where func_info will provide function range and type_id corresponding to each function. The func_info_rec_size is introduced in the UAPI to specify struct bpf_func_info size passed from user space. This intends to make bpf_func_info structure growable in the future. If the kernel gets a different bpf_func_info size from userspace, it will try to handle user request with part of bpf_func_info it can understand. In this patch, kernel can understand struct bpf_func_info { __u32 insn_offset; __u32 type_id; }; If user passed a bpf func_info record size of 16 bytes, the kernel can still handle part of records with the above definition. If verifier agrees with function range provided by the user, the bpf_prog ksym for each function will use the func name provided in the type_id, which is supposed to provide better encoding as it is not limited by 16 bytes program name limitation and this is better for bpf program which contains multiple subprograms. The bpf_prog_info interface is also extended to return btf_id, func_info, func_info_rec_size and func_info_cnt to userspace, so userspace can print out the function prototype for each xlated function. The insn_offset in the returned func_info corresponds to the insn offset for xlated functions. With other jit related fields in bpf_prog_info, userspace can also print out function prototypes for each jited function. Signed-off-by: Yonghong Song Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 5 +- include/linux/bpf_verifier.h | 1 + include/linux/btf.h | 2 + include/uapi/linux/bpf.h | 13 ++++ kernel/bpf/btf.c | 4 +- kernel/bpf/core.c | 13 ++++ kernel/bpf/syscall.c | 59 +++++++++++++++-- kernel/bpf/verifier.c | 120 ++++++++++++++++++++++++++++++++++- 8 files changed, 209 insertions(+), 8 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 987815152629..7f0e225bf630 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -316,6 +316,8 @@ struct bpf_prog_aux { void *security; #endif struct bpf_prog_offload *offload; + struct btf *btf; + u32 type_id; /* type id for this prog/func */ union { struct work_struct work; struct rcu_head rcu; @@ -527,7 +529,8 @@ static inline void bpf_long_memcpy(void *dst, const void *src, u32 size) } /* verify correctness of eBPF program */ -int bpf_check(struct bpf_prog **fp, union bpf_attr *attr); +int bpf_check(struct bpf_prog **fp, union bpf_attr *attr, + union bpf_attr __user *uattr); void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth); /* Map specifics */ diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 11f5df1092d9..204382f46fd8 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -204,6 +204,7 @@ static inline bool bpf_verifier_log_needed(const struct bpf_verifier_log *log) struct bpf_subprog_info { u32 start; /* insn idx of function entry point */ u16 stack_depth; /* max. stack depth used by this function */ + u32 type_id; /* btf type_id for this subprog */ }; /* single container for all structs diff --git a/include/linux/btf.h b/include/linux/btf.h index e076c4697049..7f2c0a4a45ea 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -46,5 +46,7 @@ void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, struct seq_file *m); int btf_get_fd_by_id(u32 id); u32 btf_id(const struct btf *btf); +const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id); +const char *btf_name_by_offset(const struct btf *btf, u32 offset); #endif diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 05d95290b848..c1554aa07465 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -338,6 +338,10 @@ union bpf_attr { * (context accesses, allowed helpers, etc). */ __u32 expected_attach_type; + __u32 prog_btf_fd; /* fd pointing to BTF type data */ + __u32 func_info_rec_size; /* userspace bpf_func_info size */ + __aligned_u64 func_info; /* func info */ + __u32 func_info_cnt; /* number of bpf_func_info records */ }; struct { /* anonymous struct used by BPF_OBJ_* commands */ @@ -2638,6 +2642,10 @@ struct bpf_prog_info { __u32 nr_jited_func_lens; __aligned_u64 jited_ksyms; __aligned_u64 jited_func_lens; + __u32 btf_id; + __u32 func_info_rec_size; + __aligned_u64 func_info; + __u32 func_info_cnt; } __attribute__((aligned(8))); struct bpf_map_info { @@ -2949,4 +2957,9 @@ struct bpf_flow_keys { }; }; +struct bpf_func_info { + __u32 insn_offset; + __u32 type_id; +}; + #endif /* _UAPI__LINUX_BPF_H__ */ diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 6a2be79b73fc..69da9169819a 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -474,7 +474,7 @@ static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) return !*src; } -static const char *btf_name_by_offset(const struct btf *btf, u32 offset) +const char *btf_name_by_offset(const struct btf *btf, u32 offset) { if (!offset) return "(anon)"; @@ -484,7 +484,7 @@ static const char *btf_name_by_offset(const struct btf *btf, u32 offset) return "(invalid-name-offset)"; } -static const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) +const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) { if (type_id > btf->nr_types) return NULL; diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 1a796e0799ec..16d77012ad3e 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -21,12 +21,14 @@ * Kris Katterjohn - Added many additional checks in bpf_check_classic() */ +#include #include #include #include #include #include #include +#include #include #include #include @@ -390,6 +392,8 @@ bpf_get_prog_addr_region(const struct bpf_prog *prog, static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) { const char *end = sym + KSYM_NAME_LEN; + const struct btf_type *type; + const char *func_name; BUILD_BUG_ON(sizeof("bpf_prog_") + sizeof(prog->tag) * 2 + @@ -404,6 +408,15 @@ static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); + + /* prog->aux->name will be ignored if full btf name is available */ + if (prog->aux->btf) { + type = btf_type_by_id(prog->aux->btf, prog->aux->type_id); + func_name = btf_name_by_offset(prog->aux->btf, type->name_off); + snprintf(sym, (size_t)(end - sym), "_%s", func_name); + return; + } + if (prog->aux->name[0]) snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); else diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index cf5040fd5434..998377808102 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1213,6 +1213,7 @@ static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock) /* bpf_prog_free_id() must be called first */ bpf_prog_free_id(prog, do_idr_lock); bpf_prog_kallsyms_del_all(prog); + btf_put(prog->aux->btf); call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); } @@ -1437,9 +1438,9 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type, } /* last field in 'union bpf_attr' used by this command */ -#define BPF_PROG_LOAD_LAST_FIELD expected_attach_type +#define BPF_PROG_LOAD_LAST_FIELD func_info_cnt -static int bpf_prog_load(union bpf_attr *attr) +static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) { enum bpf_prog_type type = attr->prog_type; struct bpf_prog *prog; @@ -1525,7 +1526,7 @@ static int bpf_prog_load(union bpf_attr *attr) goto free_prog; /* run eBPF verifier */ - err = bpf_check(&prog, attr); + err = bpf_check(&prog, attr, uattr); if (err < 0) goto free_used_maps; @@ -2079,6 +2080,7 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, info.xlated_prog_len = 0; info.nr_jited_ksyms = 0; info.nr_jited_func_lens = 0; + info.func_info_cnt = 0; goto done; } @@ -2216,6 +2218,55 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, } } + if (prog->aux->btf) { + u32 ucnt, urec_size; + + info.btf_id = btf_id(prog->aux->btf); + + ucnt = info.func_info_cnt; + info.func_info_cnt = prog->aux->func_cnt ? : 1; + urec_size = info.func_info_rec_size; + info.func_info_rec_size = sizeof(struct bpf_func_info); + if (ucnt) { + /* expect passed-in urec_size is what the kernel expects */ + if (urec_size != info.func_info_rec_size) + return -EINVAL; + + if (bpf_dump_raw_ok()) { + struct bpf_func_info kern_finfo; + char __user *user_finfo; + u32 i, insn_offset; + + user_finfo = u64_to_user_ptr(info.func_info); + if (prog->aux->func_cnt) { + ucnt = min_t(u32, info.func_info_cnt, ucnt); + insn_offset = 0; + for (i = 0; i < ucnt; i++) { + kern_finfo.insn_offset = insn_offset; + kern_finfo.type_id = prog->aux->func[i]->aux->type_id; + if (copy_to_user(user_finfo, &kern_finfo, + sizeof(kern_finfo))) + return -EFAULT; + + /* func[i]->len holds the prog len */ + insn_offset += prog->aux->func[i]->len; + user_finfo += urec_size; + } + } else { + kern_finfo.insn_offset = 0; + kern_finfo.type_id = prog->aux->type_id; + if (copy_to_user(user_finfo, &kern_finfo, + sizeof(kern_finfo))) + return -EFAULT; + } + } else { + info.func_info_cnt = 0; + } + } + } else { + info.func_info_cnt = 0; + } + done: if (copy_to_user(uinfo, &info, info_len) || put_user(info_len, &uattr->info.info_len)) @@ -2501,7 +2552,7 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz err = map_get_next_key(&attr); break; case BPF_PROG_LOAD: - err = bpf_prog_load(&attr); + err = bpf_prog_load(&attr, uattr); break; case BPF_OBJ_PIN: err = bpf_obj_pin(&attr); diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index b5222aa61d54..f102c4fd0c5a 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -11,10 +11,12 @@ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. */ +#include #include #include #include #include +#include #include #include #include @@ -4639,6 +4641,114 @@ static int check_cfg(struct bpf_verifier_env *env) return ret; } +/* The minimum supported BTF func info size */ +#define MIN_BPF_FUNCINFO_SIZE 8 +#define MAX_FUNCINFO_REC_SIZE 252 + +static int check_btf_func(struct bpf_prog *prog, struct bpf_verifier_env *env, + union bpf_attr *attr, union bpf_attr __user *uattr) +{ + u32 i, nfuncs, urec_size, min_size, prev_offset; + u32 krec_size = sizeof(struct bpf_func_info); + struct bpf_func_info krecord = {}; + const struct btf_type *type; + void __user *urecord; + struct btf *btf; + int ret = 0; + + nfuncs = attr->func_info_cnt; + if (!nfuncs) + return 0; + + if (nfuncs != env->subprog_cnt) { + verbose(env, "number of funcs in func_info doesn't match number of subprogs\n"); + return -EINVAL; + } + + urec_size = attr->func_info_rec_size; + if (urec_size < MIN_BPF_FUNCINFO_SIZE || + urec_size > MAX_FUNCINFO_REC_SIZE || + urec_size % sizeof(u32)) { + verbose(env, "invalid func info rec size %u\n", urec_size); + return -EINVAL; + } + + btf = btf_get_by_fd(attr->prog_btf_fd); + if (IS_ERR(btf)) { + verbose(env, "unable to get btf from fd\n"); + return PTR_ERR(btf); + } + + urecord = u64_to_user_ptr(attr->func_info); + min_size = min_t(u32, krec_size, urec_size); + + for (i = 0; i < nfuncs; i++) { + ret = bpf_check_uarg_tail_zero(urecord, krec_size, urec_size); + if (ret) { + if (ret == -E2BIG) { + verbose(env, "nonzero tailing record in func info"); + /* set the size kernel expects so loader can zero + * out the rest of the record. + */ + if (put_user(min_size, &uattr->func_info_rec_size)) + ret = -EFAULT; + } + goto free_btf; + } + + if (copy_from_user(&krecord, urecord, min_size)) { + ret = -EFAULT; + goto free_btf; + } + + /* check insn_offset */ + if (i == 0) { + if (krecord.insn_offset) { + verbose(env, + "nonzero insn_offset %u for the first func info record", + krecord.insn_offset); + ret = -EINVAL; + goto free_btf; + } + } else if (krecord.insn_offset <= prev_offset) { + verbose(env, + "same or smaller insn offset (%u) than previous func info record (%u)", + krecord.insn_offset, prev_offset); + ret = -EINVAL; + goto free_btf; + } + + if (env->subprog_info[i].start != krecord.insn_offset) { + verbose(env, "func_info BTF section doesn't match subprog layout in BPF program\n"); + ret = -EINVAL; + goto free_btf; + } + + /* check type_id */ + type = btf_type_by_id(btf, krecord.type_id); + if (!type || BTF_INFO_KIND(type->info) != BTF_KIND_FUNC) { + verbose(env, "invalid type id %d in func info", + krecord.type_id); + ret = -EINVAL; + goto free_btf; + } + + if (i == 0) + prog->aux->type_id = krecord.type_id; + env->subprog_info[i].type_id = krecord.type_id; + + prev_offset = krecord.insn_offset; + urecord += urec_size; + } + + prog->aux->btf = btf; + return 0; + +free_btf: + btf_put(btf); + return ret; +} + /* check %cur's range satisfies %old's */ static bool range_within(struct bpf_reg_state *old, struct bpf_reg_state *cur) @@ -5939,6 +6049,9 @@ static int jit_subprogs(struct bpf_verifier_env *env) func[i]->aux->name[0] = 'F'; func[i]->aux->stack_depth = env->subprog_info[i].stack_depth; func[i]->jit_requested = 1; + /* the btf will be freed only at prog->aux */ + func[i]->aux->btf = prog->aux->btf; + func[i]->aux->type_id = env->subprog_info[i].type_id; func[i] = bpf_int_jit_compile(func[i]); if (!func[i]->jited) { err = -ENOTSUPP; @@ -6325,7 +6438,8 @@ static void free_states(struct bpf_verifier_env *env) kfree(env->explored_states); } -int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) +int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, + union bpf_attr __user *uattr) { struct bpf_verifier_env *env; struct bpf_verifier_log *log; @@ -6397,6 +6511,10 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) if (ret < 0) goto skip_full_check; + ret = check_btf_func(env->prog, env, attr, uattr); + if (ret < 0) + goto skip_full_check; + ret = do_check(env); if (env->cur_state) { free_verifier_state(env->cur_state, true); From cc19435cb2ee34a3663f0be69f3a4647795b0417 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 19 Nov 2018 15:29:13 -0800 Subject: [PATCH 06/13] tools/bpf: sync kernel uapi bpf.h header to tools directory The kernel uapi bpf.h is synced to tools directory. Signed-off-by: Yonghong Song Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- tools/include/uapi/linux/bpf.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 05d95290b848..c1554aa07465 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -338,6 +338,10 @@ union bpf_attr { * (context accesses, allowed helpers, etc). */ __u32 expected_attach_type; + __u32 prog_btf_fd; /* fd pointing to BTF type data */ + __u32 func_info_rec_size; /* userspace bpf_func_info size */ + __aligned_u64 func_info; /* func info */ + __u32 func_info_cnt; /* number of bpf_func_info records */ }; struct { /* anonymous struct used by BPF_OBJ_* commands */ @@ -2638,6 +2642,10 @@ struct bpf_prog_info { __u32 nr_jited_func_lens; __aligned_u64 jited_ksyms; __aligned_u64 jited_func_lens; + __u32 btf_id; + __u32 func_info_rec_size; + __aligned_u64 func_info; + __u32 func_info_cnt; } __attribute__((aligned(8))); struct bpf_map_info { @@ -2949,4 +2957,9 @@ struct bpf_flow_keys { }; }; +struct bpf_func_info { + __u32 insn_offset; + __u32 type_id; +}; + #endif /* _UAPI__LINUX_BPF_H__ */ From 7e0d0fb5522a388700ceff723af98c47ffa8a0a9 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 19 Nov 2018 15:29:14 -0800 Subject: [PATCH 07/13] tools/bpf: add new fields for program load in lib/bpf The new fields are added for program load in lib/bpf so application uses api bpf_load_program_xattr() is able to load program with btf and func_info data. This functionality will be used in next patch by bpf selftest test_btf. Signed-off-by: Yonghong Song Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/bpf.c | 4 ++++ tools/lib/bpf/bpf.h | 4 ++++ 2 files changed, 8 insertions(+) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 961e1b9fc592..9b5cf22c4e64 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -205,6 +205,10 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, attr.log_level = 0; attr.kern_version = load_attr->kern_version; attr.prog_ifindex = load_attr->prog_ifindex; + attr.prog_btf_fd = load_attr->prog_btf_fd; + attr.func_info_rec_size = load_attr->func_info_rec_size; + attr.func_info_cnt = load_attr->func_info_cnt; + attr.func_info = ptr_to_u64(load_attr->func_info); memcpy(attr.prog_name, load_attr->name, min(name_len, BPF_OBJ_NAME_LEN - 1)); diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 26a51538213c..8bdfd806253a 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -74,6 +74,10 @@ struct bpf_load_program_attr { const char *license; __u32 kern_version; __u32 prog_ifindex; + __u32 prog_btf_fd; + __u32 func_info_rec_size; + const void *func_info; + __u32 func_info_cnt; }; /* Flags to direct loading requirements */ From 4798c4ba3ba94e4da37b2557dfda04f80a94e8d5 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 19 Nov 2018 15:29:15 -0800 Subject: [PATCH 08/13] tools/bpf: extends test_btf to test load/retrieve func_type info A two function bpf program is loaded with btf and func_info. After successful prog load, the bpf_get_info syscall is called to retrieve prog info to ensure the types returned from the kernel matches the types passed to the kernel from the user space. Several negative tests are also added to test loading/retriving of func_type info. Signed-off-by: Yonghong Song Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/test_btf.c | 332 ++++++++++++++++++++++++- 1 file changed, 329 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index e0eeee5c8c04..8fd3a16fea4d 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -5,6 +5,7 @@ #include #include #include +#include #include #include #include @@ -22,9 +23,13 @@ #include "bpf_rlimit.h" #include "bpf_util.h" +#define MAX_INSNS 512 +#define MAX_SUBPROGS 16 + static uint32_t pass_cnt; static uint32_t error_cnt; static uint32_t skip_cnt; +static bool jit_enabled; #define CHECK(condition, format...) ({ \ int __ret = !!(condition); \ @@ -60,6 +65,24 @@ static int __base_pr(const char *format, ...) return err; } +static bool is_jit_enabled(void) +{ + const char *jit_sysctl = "/proc/sys/net/core/bpf_jit_enable"; + bool enabled = false; + int sysctl_fd; + + sysctl_fd = open(jit_sysctl, 0, O_RDONLY); + if (sysctl_fd != -1) { + char tmpc; + + if (read(sysctl_fd, &tmpc, sizeof(tmpc)) == 1) + enabled = (tmpc != '0'); + close(sysctl_fd); + } + + return enabled; +} + #define BTF_INFO_ENC(kind, root, vlen) \ ((!!(root) << 31) | ((kind) << 24) | ((vlen) & BTF_MAX_VLEN)) @@ -115,6 +138,7 @@ static struct args { bool get_info_test; bool pprint_test; bool always_log; + bool func_type_test; } args; static char btf_log_buf[BTF_LOG_BUF_SIZE]; @@ -2947,16 +2971,310 @@ static int test_pprint(void) return err; } +static struct btf_func_type_test { + const char *descr; + const char *str_sec; + __u32 raw_types[MAX_NR_RAW_TYPES]; + __u32 str_sec_size; + struct bpf_insn insns[MAX_INSNS]; + __u32 prog_type; + __u32 func_info[MAX_SUBPROGS][2]; + __u32 func_info_rec_size; + __u32 func_info_cnt; + bool expected_prog_load_failure; +} func_type_test[] = { +{ + .descr = "func_type (main func + one sub)", + .raw_types = { + BTF_TYPE_INT_ENC(NAME_TBD, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(NAME_TBD, 0, 0, 32, 4), /* [2] */ + BTF_FUNC_PROTO_ENC(1, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + BTF_FUNC_PROTO_ENC(1, 2), /* [4] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_ENC(NAME_TBD, 3), /* [5] */ + BTF_FUNC_ENC(NAME_TBD, 4), /* [6] */ + BTF_END_RAW, + }, + .str_sec = "\0int\0unsigned int\0a\0b\0c\0d\0funcA\0funcB", + .str_sec_size = sizeof("\0int\0unsigned int\0a\0b\0c\0d\0funcA\0funcB"), + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + BPF_MOV64_IMM(BPF_REG_0, 2), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .func_info = { {0, 5}, {3, 6} }, + .func_info_rec_size = 8, + .func_info_cnt = 2, +}, + +{ + .descr = "func_type (Incorrect func_info_rec_size)", + .raw_types = { + BTF_TYPE_INT_ENC(NAME_TBD, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(NAME_TBD, 0, 0, 32, 4), /* [2] */ + BTF_FUNC_PROTO_ENC(1, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + BTF_FUNC_PROTO_ENC(1, 2), /* [4] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_ENC(NAME_TBD, 3), /* [5] */ + BTF_FUNC_ENC(NAME_TBD, 4), /* [6] */ + BTF_END_RAW, + }, + .str_sec = "\0int\0unsigned int\0a\0b\0c\0d\0funcA\0funcB", + .str_sec_size = sizeof("\0int\0unsigned int\0a\0b\0c\0d\0funcA\0funcB"), + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + BPF_MOV64_IMM(BPF_REG_0, 2), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .func_info = { {0, 5}, {3, 6} }, + .func_info_rec_size = 4, + .func_info_cnt = 2, + .expected_prog_load_failure = true, +}, + +{ + .descr = "func_type (Incorrect func_info_cnt)", + .raw_types = { + BTF_TYPE_INT_ENC(NAME_TBD, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(NAME_TBD, 0, 0, 32, 4), /* [2] */ + BTF_FUNC_PROTO_ENC(1, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + BTF_FUNC_PROTO_ENC(1, 2), /* [4] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_ENC(NAME_TBD, 3), /* [5] */ + BTF_FUNC_ENC(NAME_TBD, 4), /* [6] */ + BTF_END_RAW, + }, + .str_sec = "\0int\0unsigned int\0a\0b\0c\0d\0funcA\0funcB", + .str_sec_size = sizeof("\0int\0unsigned int\0a\0b\0c\0d\0funcA\0funcB"), + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + BPF_MOV64_IMM(BPF_REG_0, 2), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .func_info = { {0, 5}, {3, 6} }, + .func_info_rec_size = 8, + .func_info_cnt = 1, + .expected_prog_load_failure = true, +}, + +{ + .descr = "func_type (Incorrect bpf_func_info.insn_offset)", + .raw_types = { + BTF_TYPE_INT_ENC(NAME_TBD, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(NAME_TBD, 0, 0, 32, 4), /* [2] */ + BTF_FUNC_PROTO_ENC(1, 2), /* [3] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + BTF_FUNC_PROTO_ENC(1, 2), /* [4] */ + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 2), + BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), + BTF_FUNC_ENC(NAME_TBD, 3), /* [5] */ + BTF_FUNC_ENC(NAME_TBD, 4), /* [6] */ + BTF_END_RAW, + }, + .str_sec = "\0int\0unsigned int\0a\0b\0c\0d\0funcA\0funcB", + .str_sec_size = sizeof("\0int\0unsigned int\0a\0b\0c\0d\0funcA\0funcB"), + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + BPF_MOV64_IMM(BPF_REG_0, 2), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .func_info = { {0, 5}, {2, 6} }, + .func_info_rec_size = 8, + .func_info_cnt = 2, + .expected_prog_load_failure = true, +}, + +}; + +static size_t probe_prog_length(const struct bpf_insn *fp) +{ + size_t len; + + for (len = MAX_INSNS - 1; len > 0; --len) + if (fp[len].code != 0 || fp[len].imm != 0) + break; + return len + 1; +} + +static int do_test_func_type(int test_num) +{ + const struct btf_func_type_test *test = &func_type_test[test_num]; + unsigned int raw_btf_size, info_len, rec_size; + int i, btf_fd = -1, prog_fd = -1, err = 0; + struct bpf_load_program_attr attr = {}; + void *raw_btf, *func_info = NULL; + struct bpf_prog_info info = {}; + struct bpf_func_info *finfo; + + fprintf(stderr, "%s......", test->descr); + raw_btf = btf_raw_create(&hdr_tmpl, test->raw_types, + test->str_sec, test->str_sec_size, + &raw_btf_size); + + if (!raw_btf) + return -1; + + *btf_log_buf = '\0'; + btf_fd = bpf_load_btf(raw_btf, raw_btf_size, + btf_log_buf, BTF_LOG_BUF_SIZE, + args.always_log); + free(raw_btf); + + if (CHECK(btf_fd == -1, "invalid btf_fd errno:%d", errno)) { + err = -1; + goto done; + } + + if (*btf_log_buf && args.always_log) + fprintf(stderr, "\n%s", btf_log_buf); + + attr.prog_type = test->prog_type; + attr.insns = test->insns; + attr.insns_cnt = probe_prog_length(attr.insns); + attr.license = "GPL"; + attr.prog_btf_fd = btf_fd; + attr.func_info_rec_size = test->func_info_rec_size; + attr.func_info_cnt = test->func_info_cnt; + attr.func_info = test->func_info; + + *btf_log_buf = '\0'; + prog_fd = bpf_load_program_xattr(&attr, btf_log_buf, + BTF_LOG_BUF_SIZE); + if (test->expected_prog_load_failure && prog_fd == -1) { + err = 0; + goto done; + } + if (CHECK(prog_fd == -1, "invalid prog_id errno:%d", errno)) { + fprintf(stderr, "%s\n", btf_log_buf); + err = -1; + goto done; + } + if (!jit_enabled) { + skip_cnt++; + fprintf(stderr, "SKIPPED, please enable sysctl bpf_jit_enable\n"); + err = 0; + goto done; + } + + /* get necessary lens */ + info_len = sizeof(struct bpf_prog_info); + err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len); + if (CHECK(err == -1, "invalid get info (1st) errno:%d", errno)) { + fprintf(stderr, "%s\n", btf_log_buf); + err = -1; + goto done; + } + if (CHECK(info.func_info_cnt != 2, + "incorrect info.func_info_cnt (1st) %d\n", + info.func_info_cnt)) { + err = -1; + goto done; + } + rec_size = info.func_info_rec_size; + if (CHECK(rec_size < 4, + "incorrect info.func_info_rec_size (1st) %d\n", rec_size)) { + err = -1; + goto done; + } + + func_info = malloc(info.func_info_cnt * rec_size); + if (CHECK(!func_info, "out of memeory")) { + err = -1; + goto done; + } + + /* reset info to only retrieve func_info related data */ + memset(&info, 0, sizeof(info)); + info.func_info_cnt = 2; + info.func_info_rec_size = rec_size; + info.func_info = ptr_to_u64(func_info); + err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len); + if (CHECK(err == -1, "invalid get info (2nd) errno:%d", errno)) { + fprintf(stderr, "%s\n", btf_log_buf); + err = -1; + goto done; + } + if (CHECK(info.func_info_cnt != 2, + "incorrect info.func_info_cnt (2nd) %d\n", + info.func_info_cnt)) { + err = -1; + goto done; + } + if (CHECK(info.func_info_rec_size != rec_size, + "incorrect info.func_info_rec_size (2nd) %d\n", + info.func_info_rec_size)) { + err = -1; + goto done; + } + + finfo = func_info; + for (i = 0; i < 2; i++) { + if (CHECK(finfo->type_id != test->func_info[i][1], + "incorrect func_type %u expected %u", + finfo->type_id, test->func_info[i][1])) { + err = -1; + goto done; + } + finfo = (void *)finfo + rec_size; + } + +done: + if (*btf_log_buf && (err || args.always_log)) + fprintf(stderr, "\n%s", btf_log_buf); + + if (btf_fd != -1) + close(btf_fd); + if (prog_fd != -1) + close(prog_fd); + free(func_info); + return err; +} + +static int test_func_type(void) +{ + unsigned int i; + int err = 0; + + for (i = 0; i < ARRAY_SIZE(func_type_test); i++) + err |= count_result(do_test_func_type(i)); + + return err; +} + static void usage(const char *cmd) { - fprintf(stderr, "Usage: %s [-l] [[-r test_num (1 - %zu)] | [-g test_num (1 - %zu)] | [-f test_num (1 - %zu)] | [-p]]\n", + fprintf(stderr, "Usage: %s [-l] [[-r test_num (1 - %zu)] |" + " [-g test_num (1 - %zu)] |" + " [-f test_num (1 - %zu)] | [-p] | [-k] ]\n", cmd, ARRAY_SIZE(raw_tests), ARRAY_SIZE(get_info_tests), ARRAY_SIZE(file_tests)); } static int parse_args(int argc, char **argv) { - const char *optstr = "lpf:r:g:"; + const char *optstr = "lpkf:r:g:"; int opt; while ((opt = getopt(argc, argv, optstr)) != -1) { @@ -2979,6 +3297,9 @@ static int parse_args(int argc, char **argv) case 'p': args.pprint_test = true; break; + case 'k': + args.func_type_test = true; + break; case 'h': usage(argv[0]); exit(0); @@ -3032,6 +3353,8 @@ int main(int argc, char **argv) if (args.always_log) libbpf_set_print(__base_pr, __base_pr, __base_pr); + jit_enabled = is_jit_enabled(); + if (args.raw_test) err |= test_raw(); @@ -3044,8 +3367,11 @@ int main(int argc, char **argv) if (args.pprint_test) err |= test_pprint(); + if (args.func_type_test) + err |= test_func_type(); + if (args.raw_test || args.get_info_test || args.file_test || - args.pprint_test) + args.pprint_test || args.func_type_test) goto done; err |= test_raw(); From 2993e0515bb44e157c17c9ba7309ba46366b6add Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 19 Nov 2018 15:29:16 -0800 Subject: [PATCH 09/13] tools/bpf: add support to read .BTF.ext sections The .BTF section is already available to encode types. These types can be used for map pretty print. The whole .BTF will be passed to the kernel as well for which kernel can verify and return to the user space for pretty print etc. The llvm patch at https://reviews.llvm.org/D53736 will generate .BTF section and one more section .BTF.ext. The .BTF.ext section encodes function type information and line information. Note that this patch set only supports function type info. The functionality is implemented in libbpf. The .BTF section can be directly loaded into the kernel, and the .BTF.ext section cannot. The loader may need to do some relocation and merging, similar to merging multiple code sections, before loading into the kernel. Signed-off-by: Yonghong Song Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/bpf.c | 46 ++++++- tools/lib/bpf/btf.c | 274 +++++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/btf.h | 50 ++++++++ tools/lib/bpf/libbpf.c | 87 ++++++++++--- 4 files changed, 442 insertions(+), 15 deletions(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 9b5cf22c4e64..836447bb4f14 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -186,6 +186,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, char *log_buf, size_t log_buf_sz) { union bpf_attr attr; + void *finfo = NULL; __u32 name_len; int fd; @@ -216,12 +217,55 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, if (fd >= 0 || !log_buf || !log_buf_sz) return fd; + /* After bpf_prog_load, the kernel may modify certain attributes + * to give user space a hint how to deal with loading failure. + * Check to see whether we can make some changes and load again. + */ + if (errno == E2BIG && attr.func_info_cnt && + attr.func_info_rec_size < load_attr->func_info_rec_size) { + __u32 actual_rec_size = load_attr->func_info_rec_size; + __u32 expected_rec_size = attr.func_info_rec_size; + __u32 finfo_cnt = load_attr->func_info_cnt; + __u64 finfo_len = actual_rec_size * finfo_cnt; + const void *orecord; + void *nrecord; + int i; + + finfo = malloc(finfo_len); + if (!finfo) + /* further try with log buffer won't help */ + return fd; + + /* zero out bytes kernel does not understand */ + orecord = load_attr->func_info; + nrecord = finfo; + for (i = 0; i < load_attr->func_info_cnt; i++) { + memcpy(nrecord, orecord, expected_rec_size); + memset(nrecord + expected_rec_size, 0, + actual_rec_size - expected_rec_size); + orecord += actual_rec_size; + nrecord += actual_rec_size; + } + + /* try with corrected func info records */ + attr.func_info = ptr_to_u64(finfo); + attr.func_info_rec_size = load_attr->func_info_rec_size; + + fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); + + if (fd >= 0 || !log_buf || !log_buf_sz) + goto done; + } + /* Try again with log */ attr.log_buf = ptr_to_u64(log_buf); attr.log_size = log_buf_sz; attr.log_level = 1; log_buf[0] = 0; - return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); + fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); +done: + free(finfo); + return fd; } int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 31225e64766f..fe87cb48a6a9 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -37,6 +37,18 @@ struct btf { int fd; }; +struct btf_ext { + void *func_info; + __u32 func_info_rec_size; + __u32 func_info_len; +}; + +/* The minimum bpf_func_info checked by the loader */ +struct bpf_func_info_min { + __u32 insn_offset; + __u32 type_id; +}; + static int btf_add_type(struct btf *btf, struct btf_type *t) { if (btf->types_size - btf->nr_types < 2) { @@ -397,3 +409,265 @@ const char *btf__name_by_offset(const struct btf *btf, __u32 offset) else return NULL; } + +static int btf_ext_validate_func_info(const void *finfo, __u32 size, + btf_print_fn_t err_log) +{ + int sec_hdrlen = sizeof(struct btf_sec_func_info); + __u32 size_left, num_records, record_size; + const struct btf_sec_func_info *sinfo; + __u64 total_record_size; + + /* At least a func_info record size */ + if (size < sizeof(__u32)) { + elog("BTF.ext func_info record size not found"); + return -EINVAL; + } + + /* The record size needs to meet below minimum standard */ + record_size = *(__u32 *)finfo; + if (record_size < sizeof(struct bpf_func_info_min) || + record_size % sizeof(__u32)) { + elog("BTF.ext func_info invalid record size"); + return -EINVAL; + } + + sinfo = finfo + sizeof(__u32); + size_left = size - sizeof(__u32); + + /* If no func_info records, return failure now so .BTF.ext + * won't be used. + */ + if (!size_left) { + elog("BTF.ext no func info records"); + return -EINVAL; + } + + while (size_left) { + if (size_left < sec_hdrlen) { + elog("BTF.ext func_info header not found"); + return -EINVAL; + } + + num_records = sinfo->num_func_info; + if (num_records == 0) { + elog("incorrect BTF.ext num_func_info"); + return -EINVAL; + } + + total_record_size = sec_hdrlen + + (__u64)num_records * record_size; + if (size_left < total_record_size) { + elog("incorrect BTF.ext num_func_info"); + return -EINVAL; + } + + size_left -= total_record_size; + sinfo = (void *)sinfo + total_record_size; + } + + return 0; +} + +static int btf_ext_parse_hdr(__u8 *data, __u32 data_size, + btf_print_fn_t err_log) +{ + const struct btf_ext_header *hdr = (struct btf_ext_header *)data; + __u32 meta_left, last_func_info_pos; + void *finfo; + + if (data_size < offsetof(struct btf_ext_header, func_info_off) || + data_size < hdr->hdr_len) { + elog("BTF.ext header not found"); + return -EINVAL; + } + + if (hdr->magic != BTF_MAGIC) { + elog("Invalid BTF.ext magic:%x\n", hdr->magic); + return -EINVAL; + } + + if (hdr->version != BTF_VERSION) { + elog("Unsupported BTF.ext version:%u\n", hdr->version); + return -ENOTSUP; + } + + if (hdr->flags) { + elog("Unsupported BTF.ext flags:%x\n", hdr->flags); + return -ENOTSUP; + } + + meta_left = data_size - hdr->hdr_len; + if (!meta_left) { + elog("BTF.ext has no data\n"); + return -EINVAL; + } + + if (meta_left < hdr->func_info_off) { + elog("Invalid BTF.ext func_info section offset:%u\n", + hdr->func_info_off); + return -EINVAL; + } + + if (hdr->func_info_off & 0x03) { + elog("BTF.ext func_info section is not aligned to 4 bytes\n"); + return -EINVAL; + } + + last_func_info_pos = hdr->hdr_len + hdr->func_info_off + + hdr->func_info_len; + if (last_func_info_pos > data_size) { + elog("Invalid BTF.ext func_info section size:%u\n", + hdr->func_info_len); + return -EINVAL; + } + + finfo = data + hdr->hdr_len + hdr->func_info_off; + return btf_ext_validate_func_info(finfo, hdr->func_info_len, + err_log); +} + +void btf_ext__free(struct btf_ext *btf_ext) +{ + if (!btf_ext) + return; + + free(btf_ext->func_info); + free(btf_ext); +} + +struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log) +{ + const struct btf_ext_header *hdr; + struct btf_ext *btf_ext; + void *org_fdata, *fdata; + __u32 hdrlen, size_u32; + int err; + + err = btf_ext_parse_hdr(data, size, err_log); + if (err) + return ERR_PTR(err); + + btf_ext = calloc(1, sizeof(struct btf_ext)); + if (!btf_ext) + return ERR_PTR(-ENOMEM); + + hdr = (const struct btf_ext_header *)data; + hdrlen = hdr->hdr_len; + size_u32 = sizeof(__u32); + fdata = malloc(hdr->func_info_len - size_u32); + if (!fdata) { + free(btf_ext); + return ERR_PTR(-ENOMEM); + } + + /* remember record size and copy rest of func_info data */ + org_fdata = data + hdrlen + hdr->func_info_off; + btf_ext->func_info_rec_size = *(__u32 *)org_fdata; + memcpy(fdata, org_fdata + size_u32, hdr->func_info_len - size_u32); + btf_ext->func_info = fdata; + btf_ext->func_info_len = hdr->func_info_len - size_u32; + + return btf_ext; +} + +int btf_ext__reloc_init(struct btf *btf, struct btf_ext *btf_ext, + const char *sec_name, void **func_info, + __u32 *func_info_rec_size, __u32 *func_info_len) +{ + __u32 sec_hdrlen = sizeof(struct btf_sec_func_info); + __u32 i, record_size, records_len; + struct btf_sec_func_info *sinfo; + const char *info_sec_name; + __s64 remain_len; + void *data; + + record_size = btf_ext->func_info_rec_size; + sinfo = btf_ext->func_info; + remain_len = btf_ext->func_info_len; + + while (remain_len > 0) { + records_len = sinfo->num_func_info * record_size; + info_sec_name = btf__name_by_offset(btf, sinfo->sec_name_off); + if (strcmp(info_sec_name, sec_name)) { + remain_len -= sec_hdrlen + records_len; + sinfo = (void *)sinfo + sec_hdrlen + records_len; + continue; + } + + data = malloc(records_len); + if (!data) + return -ENOMEM; + + memcpy(data, sinfo->data, records_len); + + /* adjust the insn_offset, the data in .BTF.ext is + * the actual byte offset, and the kernel expects + * the offset in term of bpf_insn. + * + * adjust the insn offset only, the rest data will + * be passed to kernel. + */ + for (i = 0; i < sinfo->num_func_info; i++) { + struct bpf_func_info_min *record; + + record = data + i * record_size; + record->insn_offset /= sizeof(struct bpf_insn); + } + + *func_info = data; + *func_info_len = records_len; + *func_info_rec_size = record_size; + return 0; + } + + return -EINVAL; +} + +int btf_ext__reloc(struct btf *btf, struct btf_ext *btf_ext, + const char *sec_name, __u32 insns_cnt, + void **func_info, __u32 *func_info_len) +{ + __u32 sec_hdrlen = sizeof(struct btf_sec_func_info); + __u32 i, record_size, existing_flen, records_len; + struct btf_sec_func_info *sinfo; + const char *info_sec_name; + __u64 remain_len; + void *data; + + record_size = btf_ext->func_info_rec_size; + sinfo = btf_ext->func_info; + remain_len = btf_ext->func_info_len; + while (remain_len > 0) { + records_len = sinfo->num_func_info * record_size; + info_sec_name = btf__name_by_offset(btf, sinfo->sec_name_off); + if (strcmp(info_sec_name, sec_name)) { + remain_len -= sec_hdrlen + records_len; + sinfo = (void *)sinfo + sec_hdrlen + records_len; + continue; + } + + existing_flen = *func_info_len; + data = realloc(*func_info, existing_flen + records_len); + if (!data) + return -ENOMEM; + + memcpy(data + existing_flen, sinfo->data, records_len); + /* adjust insn_offset only, the rest data will be passed + * to the kernel. + */ + for (i = 0; i < sinfo->num_func_info; i++) { + struct bpf_func_info_min *record; + + record = data + existing_flen + i * record_size; + record->insn_offset = + record->insn_offset / sizeof(struct bpf_insn) + + insns_cnt; + } + *func_info = data; + *func_info_len = existing_flen + records_len; + return 0; + } + + return -EINVAL; +} diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index b77e7080f7e7..578171e8cb26 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -11,10 +11,51 @@ #endif #define BTF_ELF_SEC ".BTF" +#define BTF_EXT_ELF_SEC ".BTF.ext" struct btf; +struct btf_ext; struct btf_type; +/* + * The .BTF.ext ELF section layout defined as + * struct btf_ext_header + * func_info subsection + * + * The func_info subsection layout: + * record size for struct bpf_func_info in the func_info subsection + * struct btf_sec_func_info for section #1 + * a list of bpf_func_info records for section #1 + * where struct bpf_func_info mimics one in include/uapi/linux/bpf.h + * but may not be identical + * struct btf_sec_func_info for section #2 + * a list of bpf_func_info records for section #2 + * ...... + * + * Note that the bpf_func_info record size in .BTF.ext may not + * be the same as the one defined in include/uapi/linux/bpf.h. + * The loader should ensure that record_size meets minimum + * requirement and pass the record as is to the kernel. The + * kernel will handle the func_info properly based on its contents. + */ +struct btf_ext_header { + __u16 magic; + __u8 version; + __u8 flags; + __u32 hdr_len; + + /* All offsets are in bytes relative to the end of this header */ + __u32 func_info_off; + __u32 func_info_len; +}; + +struct btf_sec_func_info { + __u32 sec_name_off; + __u32 num_func_info; + /* Followed by num_func_info number of bpf func_info records */ + __u8 data[0]; +}; + typedef int (*btf_print_fn_t)(const char *, ...) __attribute__((format(printf, 1, 2))); @@ -29,4 +70,13 @@ LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id); LIBBPF_API int btf__fd(const struct btf *btf); LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset); +struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log); +void btf_ext__free(struct btf_ext *btf_ext); +int btf_ext__reloc_init(struct btf *btf, struct btf_ext *btf_ext, + const char *sec_name, void **func_info, + __u32 *func_info_rec_size, __u32 *func_info_len); +int btf_ext__reloc(struct btf *btf, struct btf_ext *btf_ext, + const char *sec_name, __u32 insns_cnt, void **func_info, + __u32 *func_info_len); + #endif /* __LIBBPF_BTF_H */ diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index a01eb9584e52..cb6565d79603 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -156,6 +156,10 @@ struct bpf_program { bpf_program_clear_priv_t clear_priv; enum bpf_attach_type expected_attach_type; + int btf_fd; + void *func_info; + __u32 func_info_rec_size; + __u32 func_info_len; }; struct bpf_map { @@ -212,6 +216,7 @@ struct bpf_object { struct list_head list; struct btf *btf; + struct btf_ext *btf_ext; void *priv; bpf_object_clear_priv_t clear_priv; @@ -241,6 +246,9 @@ void bpf_program__unload(struct bpf_program *prog) prog->instances.nr = -1; zfree(&prog->instances.fds); + + zclose(prog->btf_fd); + zfree(&prog->func_info); } static void bpf_program__exit(struct bpf_program *prog) @@ -315,6 +323,7 @@ bpf_program__init(void *data, size_t size, char *section_name, int idx, prog->instances.fds = NULL; prog->instances.nr = -1; prog->type = BPF_PROG_TYPE_KPROBE; + prog->btf_fd = -1; return 0; errout: @@ -807,6 +816,15 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) BTF_ELF_SEC, PTR_ERR(obj->btf)); obj->btf = NULL; } + } else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) { + obj->btf_ext = btf_ext__new(data->d_buf, data->d_size, + __pr_debug); + if (IS_ERR(obj->btf_ext)) { + pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", + BTF_EXT_ELF_SEC, + PTR_ERR(obj->btf_ext)); + obj->btf_ext = NULL; + } } else if (sh.sh_type == SHT_SYMTAB) { if (obj->efile.symbols) { pr_warning("bpf: multiple SYMTAB in %s\n", @@ -1190,6 +1208,7 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj, struct bpf_insn *insn, *new_insn; struct bpf_program *text; size_t new_cnt; + int err; if (relo->type != RELO_CALL) return -LIBBPF_ERRNO__RELOC; @@ -1212,6 +1231,20 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj, pr_warning("oom in prog realloc\n"); return -ENOMEM; } + + if (obj->btf && obj->btf_ext) { + err = btf_ext__reloc(obj->btf, obj->btf_ext, + text->section_name, + prog->insns_cnt, + &prog->func_info, + &prog->func_info_len); + if (err) { + pr_warning("error in btf_ext__reloc for sec %s\n", + text->section_name); + return err; + } + } + memcpy(new_insn + prog->insns_cnt, text->insns, text->insns_cnt * sizeof(*insn)); prog->insns = new_insn; @@ -1231,7 +1264,24 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj) { int i, err; - if (!prog || !prog->reloc_desc) + if (!prog) + return 0; + + if (obj->btf && obj->btf_ext) { + err = btf_ext__reloc_init(obj->btf, obj->btf_ext, + prog->section_name, + &prog->func_info, + &prog->func_info_rec_size, + &prog->func_info_len); + if (err) { + pr_warning("err in btf_ext__reloc_init for sec %s\n", + prog->section_name); + return err; + } + prog->btf_fd = btf__fd(obj->btf); + } + + if (!prog->reloc_desc) return 0; for (i = 0; i < prog->nr_reloc; i++) { @@ -1319,9 +1369,9 @@ static int bpf_object__collect_reloc(struct bpf_object *obj) } static int -load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, - const char *name, struct bpf_insn *insns, int insns_cnt, - char *license, __u32 kern_version, int *pfd, int prog_ifindex) +load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, + char *license, __u32 kern_version, int *pfd, + __u32 func_info_cnt) { struct bpf_load_program_attr load_attr; char *cp, errmsg[STRERR_BUFSIZE]; @@ -1329,14 +1379,18 @@ load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, int ret; memset(&load_attr, 0, sizeof(struct bpf_load_program_attr)); - load_attr.prog_type = type; - load_attr.expected_attach_type = expected_attach_type; - load_attr.name = name; + load_attr.prog_type = prog->type; + load_attr.expected_attach_type = prog->expected_attach_type; + load_attr.name = prog->name; load_attr.insns = insns; load_attr.insns_cnt = insns_cnt; load_attr.license = license; load_attr.kern_version = kern_version; - load_attr.prog_ifindex = prog_ifindex; + load_attr.prog_ifindex = prog->prog_ifindex; + load_attr.prog_btf_fd = prog->btf_fd; + load_attr.func_info = prog->func_info; + load_attr.func_info_rec_size = prog->func_info_rec_size; + load_attr.func_info_cnt = func_info_cnt; if (!load_attr.insns || !load_attr.insns_cnt) return -EINVAL; @@ -1394,8 +1448,14 @@ int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_version) { + __u32 func_info_cnt; int err = 0, fd, i; + if (prog->func_info_len == 0) + func_info_cnt = 0; + else + func_info_cnt = prog->func_info_len / prog->func_info_rec_size; + if (prog->instances.nr < 0 || !prog->instances.fds) { if (prog->preprocessor) { pr_warning("Internal error: can't load program '%s'\n", @@ -1417,10 +1477,9 @@ bpf_program__load(struct bpf_program *prog, pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n", prog->section_name, prog->instances.nr); } - err = load_program(prog->type, prog->expected_attach_type, - prog->name, prog->insns, prog->insns_cnt, + err = load_program(prog, prog->insns, prog->insns_cnt, license, kern_version, &fd, - prog->prog_ifindex); + func_info_cnt); if (!err) prog->instances.fds[0] = fd; goto out; @@ -1448,11 +1507,10 @@ bpf_program__load(struct bpf_program *prog, continue; } - err = load_program(prog->type, prog->expected_attach_type, - prog->name, result.new_insn_ptr, + err = load_program(prog, result.new_insn_ptr, result.new_insn_cnt, license, kern_version, &fd, - prog->prog_ifindex); + func_info_cnt); if (err) { pr_warning("Loading the %dth instance of program '%s' failed\n", @@ -2120,6 +2178,7 @@ void bpf_object__close(struct bpf_object *obj) bpf_object__elf_finish(obj); bpf_object__unload(obj); btf__free(obj->btf); + btf_ext__free(obj->btf_ext); for (i = 0; i < obj->nr_maps; i++) { zfree(&obj->maps[i].name); From 9ce6ae22c8e878aee7a96836b2ed9fd9a8173e41 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 19 Nov 2018 15:29:17 -0800 Subject: [PATCH 10/13] tools/bpf: do not use pahole if clang/llvm can generate BTF sections Add additional checks in tools/testing/selftests/bpf and samples/bpf such that if clang/llvm compiler can generate BTF sections, do not use pahole. Signed-off-by: Yonghong Song Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- samples/bpf/Makefile | 8 ++++++++ tools/testing/selftests/bpf/Makefile | 8 ++++++++ 2 files changed, 16 insertions(+) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index be0a961450bc..35444f4a846b 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -208,12 +208,20 @@ endif BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris) BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF) BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm') +BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \ + $(CLANG) -target bpf -O2 -g -c -x c - -o ./llvm_btf_verify.o; \ + readelf -S ./llvm_btf_verify.o | grep BTF; \ + /bin/rm -f ./llvm_btf_verify.o) +ifneq ($(BTF_LLVM_PROBE),) + EXTRA_CFLAGS += -g +else ifneq ($(and $(BTF_LLC_PROBE),$(BTF_PAHOLE_PROBE),$(BTF_OBJCOPY_PROBE)),) EXTRA_CFLAGS += -g LLC_FLAGS += -mattr=dwarfris DWARF2BTF = y endif +endif # Trick to allow make to be run from this directory all: diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 57b4712a6276..1dde03ea1484 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -126,7 +126,14 @@ $(OUTPUT)/test_stack_map.o: test_queue_stack_map.h BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris) BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF) BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm') +BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \ + $(CLANG) -target bpf -O2 -g -c -x c - -o ./llvm_btf_verify.o; \ + readelf -S ./llvm_btf_verify.o | grep BTF; \ + /bin/rm -f ./llvm_btf_verify.o) +ifneq ($(BTF_LLVM_PROBE),) + CLANG_FLAGS += -g +else ifneq ($(BTF_LLC_PROBE),) ifneq ($(BTF_PAHOLE_PROBE),) ifneq ($(BTF_OBJCOPY_PROBE),) @@ -136,6 +143,7 @@ ifneq ($(BTF_OBJCOPY_PROBE),) endif endif endif +endif # Have one program compiled without "-target bpf" to test whether libbpf loads # it successfully From d7f5b5e051554c91bab995b67101af4625af591a Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 19 Nov 2018 15:29:18 -0800 Subject: [PATCH 11/13] tools/bpf: refactor to implement btf_get_from_id() in lib/bpf The function get_btf() is implemented in tools/bpf/bpftool/map.c to get a btf structure given a map_info. This patch refactored this function to be function btf_get_from_id() in tools/lib/bpf so that it can be used later. Signed-off-by: Yonghong Song Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- tools/bpf/bpftool/map.c | 68 ++-------------------------------------- tools/lib/bpf/btf.c | 69 +++++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/btf.h | 1 + 3 files changed, 72 insertions(+), 66 deletions(-) diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index dc9a8967ab8c..a1ae2a3e9fef 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -215,70 +215,6 @@ static int do_dump_btf(const struct btf_dumper *d, return ret; } -static int get_btf(struct bpf_map_info *map_info, struct btf **btf) -{ - struct bpf_btf_info btf_info = { 0 }; - __u32 len = sizeof(btf_info); - __u32 last_size; - int btf_fd; - void *ptr; - int err; - - err = 0; - *btf = NULL; - btf_fd = bpf_btf_get_fd_by_id(map_info->btf_id); - if (btf_fd < 0) - return 0; - - /* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so - * let's start with a sane default - 4KiB here - and resize it only if - * bpf_obj_get_info_by_fd() needs a bigger buffer. - */ - btf_info.btf_size = 4096; - last_size = btf_info.btf_size; - ptr = malloc(last_size); - if (!ptr) { - err = -ENOMEM; - goto exit_free; - } - - bzero(ptr, last_size); - btf_info.btf = ptr_to_u64(ptr); - err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); - - if (!err && btf_info.btf_size > last_size) { - void *temp_ptr; - - last_size = btf_info.btf_size; - temp_ptr = realloc(ptr, last_size); - if (!temp_ptr) { - err = -ENOMEM; - goto exit_free; - } - ptr = temp_ptr; - bzero(ptr, last_size); - btf_info.btf = ptr_to_u64(ptr); - err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); - } - - if (err || btf_info.btf_size > last_size) { - err = errno; - goto exit_free; - } - - *btf = btf__new((__u8 *)btf_info.btf, btf_info.btf_size, NULL); - if (IS_ERR(*btf)) { - err = PTR_ERR(*btf); - *btf = NULL; - } - -exit_free: - close(btf_fd); - free(ptr); - - return err; -} - static json_writer_t *get_btf_writer(void) { json_writer_t *jw = jsonw_new(stdout); @@ -775,7 +711,7 @@ static int do_dump(int argc, char **argv) prev_key = NULL; - err = get_btf(&info, &btf); + err = btf_get_from_id(info.btf_id, &btf); if (err) { p_err("failed to get btf"); goto exit_free; @@ -919,7 +855,7 @@ static int do_lookup(int argc, char **argv) } /* here means bpf_map_lookup_elem() succeeded */ - err = get_btf(&info, &btf); + err = btf_get_from_id(info.btf_id, &btf); if (err) { p_err("failed to get btf"); goto exit_free; diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index fe87cb48a6a9..13ddc4bd24ee 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -49,6 +49,11 @@ struct bpf_func_info_min { __u32 type_id; }; +static inline __u64 ptr_to_u64(const void *ptr) +{ + return (__u64) (unsigned long) ptr; +} + static int btf_add_type(struct btf *btf, struct btf_type *t) { if (btf->types_size - btf->nr_types < 2) { @@ -410,6 +415,70 @@ const char *btf__name_by_offset(const struct btf *btf, __u32 offset) return NULL; } +int btf_get_from_id(__u32 id, struct btf **btf) +{ + struct bpf_btf_info btf_info = { 0 }; + __u32 len = sizeof(btf_info); + __u32 last_size; + int btf_fd; + void *ptr; + int err; + + err = 0; + *btf = NULL; + btf_fd = bpf_btf_get_fd_by_id(id); + if (btf_fd < 0) + return 0; + + /* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so + * let's start with a sane default - 4KiB here - and resize it only if + * bpf_obj_get_info_by_fd() needs a bigger buffer. + */ + btf_info.btf_size = 4096; + last_size = btf_info.btf_size; + ptr = malloc(last_size); + if (!ptr) { + err = -ENOMEM; + goto exit_free; + } + + bzero(ptr, last_size); + btf_info.btf = ptr_to_u64(ptr); + err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); + + if (!err && btf_info.btf_size > last_size) { + void *temp_ptr; + + last_size = btf_info.btf_size; + temp_ptr = realloc(ptr, last_size); + if (!temp_ptr) { + err = -ENOMEM; + goto exit_free; + } + ptr = temp_ptr; + bzero(ptr, last_size); + btf_info.btf = ptr_to_u64(ptr); + err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); + } + + if (err || btf_info.btf_size > last_size) { + err = errno; + goto exit_free; + } + + *btf = btf__new((__u8 *)btf_info.btf, btf_info.btf_size, NULL); + if (IS_ERR(*btf)) { + err = PTR_ERR(*btf); + *btf = NULL; + } + +exit_free: + close(btf_fd); + free(ptr); + + return err; +} + static int btf_ext_validate_func_info(const void *finfo, __u32 size, btf_print_fn_t err_log) { diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index 578171e8cb26..386b2ffc32a3 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -69,6 +69,7 @@ LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id); LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id); LIBBPF_API int btf__fd(const struct btf *btf); LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset); +LIBBPF_API int btf_get_from_id(__u32 id, struct btf **btf); struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log); void btf_ext__free(struct btf_ext *btf_ext); From 999d82cbc04416cc7f2b5cb6daab947c16f0fd3a Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 19 Nov 2018 15:29:20 -0800 Subject: [PATCH 12/13] tools/bpf: enhance test_btf file testing to test func info Change the bpf programs test_btf_haskv.c and test_btf_nokv.c to have two sections, and enhance test_btf.c test_file feature to test btf func_info returned by the kernel. Signed-off-by: Yonghong Song Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/test_btf.c | 117 +++++++++++++++++-- tools/testing/selftests/bpf/test_btf_haskv.c | 16 ++- tools/testing/selftests/bpf/test_btf_nokv.c | 16 ++- 3 files changed, 136 insertions(+), 13 deletions(-) diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index 8fd3a16fea4d..7b1b160d6e67 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -2434,13 +2434,13 @@ static struct btf_file_test file_tests[] = { }, }; -static int file_has_btf_elf(const char *fn) +static int file_has_btf_elf(const char *fn, bool *has_btf_ext) { Elf_Scn *scn = NULL; GElf_Ehdr ehdr; + int ret = 0; int elf_fd; Elf *elf; - int ret; if (CHECK(elf_version(EV_CURRENT) == EV_NONE, "elf_version(EV_CURRENT) == EV_NONE")) @@ -2472,14 +2472,12 @@ static int file_has_btf_elf(const char *fn) } sh_name = elf_strptr(elf, ehdr.e_shstrndx, sh.sh_name); - if (!strcmp(sh_name, BTF_ELF_SEC)) { + if (!strcmp(sh_name, BTF_ELF_SEC)) ret = 1; - goto done; - } + if (!strcmp(sh_name, BTF_EXT_ELF_SEC)) + *has_btf_ext = true; } - ret = 0; - done: close(elf_fd); elf_end(elf); @@ -2489,15 +2487,24 @@ static int file_has_btf_elf(const char *fn) static int do_test_file(unsigned int test_num) { const struct btf_file_test *test = &file_tests[test_num - 1]; + const char *expected_fnames[] = {"_dummy_tracepoint", + "test_long_fname_1", + "test_long_fname_2"}; + struct bpf_prog_info info = {}; struct bpf_object *obj = NULL; + struct bpf_func_info *finfo; struct bpf_program *prog; + __u32 info_len, rec_size; + bool has_btf_ext = false; + struct btf *btf = NULL; + void *func_info = NULL; struct bpf_map *map; - int err; + int i, err, prog_fd; fprintf(stderr, "BTF libbpf test[%u] (%s): ", test_num, test->file); - err = file_has_btf_elf(test->file); + err = file_has_btf_elf(test->file, &has_btf_ext); if (err == -1) return err; @@ -2525,6 +2532,7 @@ static int do_test_file(unsigned int test_num) err = bpf_object__load(obj); if (CHECK(err < 0, "bpf_object__load: %d", err)) goto done; + prog_fd = bpf_program__fd(prog); map = bpf_object__find_map_by_name(obj, "btf_map"); if (CHECK(!map, "btf_map not found")) { @@ -2539,9 +2547,100 @@ static int do_test_file(unsigned int test_num) test->btf_kv_notfound)) goto done; + if (!jit_enabled || !has_btf_ext) + goto skip_jit; + + /* get necessary program info */ + info_len = sizeof(struct bpf_prog_info); + err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len); + + if (CHECK(err == -1, "invalid get info (1st) errno:%d", errno)) { + fprintf(stderr, "%s\n", btf_log_buf); + err = -1; + goto done; + } + if (CHECK(info.func_info_cnt != 3, + "incorrect info.func_info_cnt (1st) %d", + info.func_info_cnt)) { + err = -1; + goto done; + } + rec_size = info.func_info_rec_size; + if (CHECK(rec_size < 4, + "incorrect info.func_info_rec_size (1st) %d\n", rec_size)) { + err = -1; + goto done; + } + + func_info = malloc(info.func_info_cnt * rec_size); + if (CHECK(!func_info, "out of memeory")) { + err = -1; + goto done; + } + + /* reset info to only retrieve func_info related data */ + memset(&info, 0, sizeof(info)); + info.func_info_cnt = 3; + info.func_info_rec_size = rec_size; + info.func_info = ptr_to_u64(func_info); + + err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len); + + if (CHECK(err == -1, "invalid get info (2nd) errno:%d", errno)) { + fprintf(stderr, "%s\n", btf_log_buf); + err = -1; + goto done; + } + if (CHECK(info.func_info_cnt != 3, + "incorrect info.func_info_cnt (2nd) %d", + info.func_info_cnt)) { + err = -1; + goto done; + } + if (CHECK(info.func_info_rec_size != rec_size, + "incorrect info.func_info_rec_size (2nd) %d", + info.func_info_rec_size)) { + err = -1; + goto done; + } + + err = btf_get_from_id(info.btf_id, &btf); + if (CHECK(err, "cannot get btf from kernel, err: %d", err)) + goto done; + + /* check three functions */ + finfo = func_info; + for (i = 0; i < 3; i++) { + const struct btf_type *t; + const char *fname; + + t = btf__type_by_id(btf, finfo->type_id); + if (CHECK(!t, "btf__type_by_id failure: id %u", + finfo->type_id)) { + err = -1; + goto done; + } + + fname = btf__name_by_offset(btf, t->name_off); + err = strcmp(fname, expected_fnames[i]); + /* for the second and third functions in .text section, + * the compiler may order them either way. + */ + if (i && err) + err = strcmp(fname, expected_fnames[3 - i]); + if (CHECK(err, "incorrect fname %s", fname ? : "")) { + err = -1; + goto done; + } + + finfo = (void *)finfo + rec_size; + } + +skip_jit: fprintf(stderr, "OK"); done: + free(func_info); bpf_object__close(obj); return err; } diff --git a/tools/testing/selftests/bpf/test_btf_haskv.c b/tools/testing/selftests/bpf/test_btf_haskv.c index b21b876f475d..e5c79fe0ffdb 100644 --- a/tools/testing/selftests/bpf/test_btf_haskv.c +++ b/tools/testing/selftests/bpf/test_btf_haskv.c @@ -24,8 +24,8 @@ struct dummy_tracepoint_args { struct sock *sock; }; -SEC("dummy_tracepoint") -int _dummy_tracepoint(struct dummy_tracepoint_args *arg) +__attribute__((noinline)) +static int test_long_fname_2(struct dummy_tracepoint_args *arg) { struct ipv_counts *counts; int key = 0; @@ -42,4 +42,16 @@ int _dummy_tracepoint(struct dummy_tracepoint_args *arg) return 0; } +__attribute__((noinline)) +static int test_long_fname_1(struct dummy_tracepoint_args *arg) +{ + return test_long_fname_2(arg); +} + +SEC("dummy_tracepoint") +int _dummy_tracepoint(struct dummy_tracepoint_args *arg) +{ + return test_long_fname_1(arg); +} + char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/test_btf_nokv.c b/tools/testing/selftests/bpf/test_btf_nokv.c index 0ed8e088eebf..434188c37774 100644 --- a/tools/testing/selftests/bpf/test_btf_nokv.c +++ b/tools/testing/selftests/bpf/test_btf_nokv.c @@ -22,8 +22,8 @@ struct dummy_tracepoint_args { struct sock *sock; }; -SEC("dummy_tracepoint") -int _dummy_tracepoint(struct dummy_tracepoint_args *arg) +__attribute__((noinline)) +static int test_long_fname_2(struct dummy_tracepoint_args *arg) { struct ipv_counts *counts; int key = 0; @@ -40,4 +40,16 @@ int _dummy_tracepoint(struct dummy_tracepoint_args *arg) return 0; } +__attribute__((noinline)) +static int test_long_fname_1(struct dummy_tracepoint_args *arg) +{ + return test_long_fname_2(arg); +} + +SEC("dummy_tracepoint") +int _dummy_tracepoint(struct dummy_tracepoint_args *arg) +{ + return test_long_fname_1(arg); +} + char _license[] SEC("license") = "GPL"; From 254471e57a86b8dc1a2cc19848e99f5d7c0558f4 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 19 Nov 2018 15:29:21 -0800 Subject: [PATCH 13/13] tools/bpf: bpftool: add support for func types This patch added support to print function signature if btf func_info is available. Note that ksym now uses function name instead of prog_name as prog_name has a limit of 16 bytes including ending '\0'. The following is a sample output for selftests test_btf with file test_btf_haskv.o for translated insns and jited insns respectively. $ bpftool prog dump xlated id 1 int _dummy_tracepoint(struct dummy_tracepoint_args * arg): 0: (85) call pc+2#bpf_prog_2dcecc18072623fc_test_long_fname_1 1: (b7) r0 = 0 2: (95) exit int test_long_fname_1(struct dummy_tracepoint_args * arg): 3: (85) call pc+1#bpf_prog_89d64e4abf0f0126_test_long_fname_2 4: (95) exit int test_long_fname_2(struct dummy_tracepoint_args * arg): 5: (b7) r2 = 0 6: (63) *(u32 *)(r10 -4) = r2 7: (79) r1 = *(u64 *)(r1 +8) ... 22: (07) r1 += 1 23: (63) *(u32 *)(r0 +4) = r1 24: (95) exit $ bpftool prog dump jited id 1 int _dummy_tracepoint(struct dummy_tracepoint_args * arg): bpf_prog_b07ccb89267cf242__dummy_tracepoint: 0: push %rbp 1: mov %rsp,%rbp ...... 3c: add $0x28,%rbp 40: leaveq 41: retq int test_long_fname_1(struct dummy_tracepoint_args * arg): bpf_prog_2dcecc18072623fc_test_long_fname_1: 0: push %rbp 1: mov %rsp,%rbp ...... 3a: add $0x28,%rbp 3e: leaveq 3f: retq int test_long_fname_2(struct dummy_tracepoint_args * arg): bpf_prog_89d64e4abf0f0126_test_long_fname_2: 0: push %rbp 1: mov %rsp,%rbp ...... 80: add $0x28,%rbp 84: leaveq 85: retq Signed-off-by: Yonghong Song Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- tools/bpf/bpftool/btf_dumper.c | 136 ++++++++++++++++++++++++++++++ tools/bpf/bpftool/main.h | 2 + tools/bpf/bpftool/prog.c | 56 ++++++++++++ tools/bpf/bpftool/xlated_dumper.c | 33 ++++++++ tools/bpf/bpftool/xlated_dumper.h | 3 + 5 files changed, 230 insertions(+) diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c index 55bc512a1831..c3fd3a7cb787 100644 --- a/tools/bpf/bpftool/btf_dumper.c +++ b/tools/bpf/bpftool/btf_dumper.c @@ -249,3 +249,139 @@ int btf_dumper_type(const struct btf_dumper *d, __u32 type_id, { return btf_dumper_do_type(d, type_id, 0, data); } + +#define BTF_PRINT_ARG(...) \ + do { \ + pos += snprintf(func_sig + pos, size - pos, \ + __VA_ARGS__); \ + if (pos >= size) \ + return -1; \ + } while (0) +#define BTF_PRINT_TYPE(type) \ + do { \ + pos = __btf_dumper_type_only(btf, type, func_sig, \ + pos, size); \ + if (pos == -1) \ + return -1; \ + } while (0) + +static int btf_dump_func(const struct btf *btf, char *func_sig, + const struct btf_type *func_proto, + const struct btf_type *func, int pos, int size); + +static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id, + char *func_sig, int pos, int size) +{ + const struct btf_type *proto_type; + const struct btf_array *array; + const struct btf_type *t; + + if (!type_id) { + BTF_PRINT_ARG("void "); + return pos; + } + + t = btf__type_by_id(btf, type_id); + + switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_INT: + BTF_PRINT_ARG("%s ", btf__name_by_offset(btf, t->name_off)); + break; + case BTF_KIND_STRUCT: + BTF_PRINT_ARG("struct %s ", + btf__name_by_offset(btf, t->name_off)); + break; + case BTF_KIND_UNION: + BTF_PRINT_ARG("union %s ", + btf__name_by_offset(btf, t->name_off)); + break; + case BTF_KIND_ENUM: + BTF_PRINT_ARG("enum %s ", + btf__name_by_offset(btf, t->name_off)); + break; + case BTF_KIND_ARRAY: + array = (struct btf_array *)(t + 1); + BTF_PRINT_TYPE(array->type); + BTF_PRINT_ARG("[%d]", array->nelems); + break; + case BTF_KIND_PTR: + BTF_PRINT_TYPE(t->type); + BTF_PRINT_ARG("* "); + break; + case BTF_KIND_UNKN: + case BTF_KIND_FWD: + case BTF_KIND_TYPEDEF: + return -1; + case BTF_KIND_VOLATILE: + BTF_PRINT_ARG("volatile "); + BTF_PRINT_TYPE(t->type); + break; + case BTF_KIND_CONST: + BTF_PRINT_ARG("const "); + BTF_PRINT_TYPE(t->type); + break; + case BTF_KIND_RESTRICT: + BTF_PRINT_ARG("restrict "); + BTF_PRINT_TYPE(t->type); + break; + case BTF_KIND_FUNC_PROTO: + pos = btf_dump_func(btf, func_sig, t, NULL, pos, size); + if (pos == -1) + return -1; + break; + case BTF_KIND_FUNC: + proto_type = btf__type_by_id(btf, t->type); + pos = btf_dump_func(btf, func_sig, proto_type, t, pos, size); + if (pos == -1) + return -1; + break; + default: + return -1; + } + + return pos; +} + +static int btf_dump_func(const struct btf *btf, char *func_sig, + const struct btf_type *func_proto, + const struct btf_type *func, int pos, int size) +{ + int i, vlen; + + BTF_PRINT_TYPE(func_proto->type); + if (func) + BTF_PRINT_ARG("%s(", btf__name_by_offset(btf, func->name_off)); + else + BTF_PRINT_ARG("("); + vlen = BTF_INFO_VLEN(func_proto->info); + for (i = 0; i < vlen; i++) { + struct btf_param *arg = &((struct btf_param *)(func_proto + 1))[i]; + + if (i) + BTF_PRINT_ARG(", "); + if (arg->type) { + BTF_PRINT_TYPE(arg->type); + BTF_PRINT_ARG("%s", + btf__name_by_offset(btf, arg->name_off)); + } else { + BTF_PRINT_ARG("..."); + } + } + BTF_PRINT_ARG(")"); + + return pos; +} + +void btf_dumper_type_only(const struct btf *btf, __u32 type_id, char *func_sig, + int size) +{ + int err; + + func_sig[0] = '\0'; + if (!btf) + return; + + err = __btf_dumper_type_only(btf, type_id, func_sig, 0, size); + if (err < 0) + func_sig[0] = '\0'; +} diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 10c6c16fae29..3e8979567cf1 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -187,6 +187,8 @@ struct btf_dumper { */ int btf_dumper_type(const struct btf_dumper *d, __u32 type_id, const void *data); +void btf_dumper_type_only(const struct btf *btf, __u32 func_type_id, + char *func_only, int size); struct nlattr; struct ifinfomsg; diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index c176e1aa66fe..37b1daf19da6 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -47,6 +47,7 @@ #include #include +#include #include #include "cfg.h" @@ -451,14 +452,19 @@ static int do_dump(int argc, char **argv) struct bpf_prog_info info = {}; unsigned int *func_lens = NULL; const char *disasm_opt = NULL; + unsigned int finfo_rec_size; unsigned int nr_func_ksyms; unsigned int nr_func_lens; struct dump_data dd = {}; __u32 len = sizeof(info); + struct btf *btf = NULL; + void *func_info = NULL; + unsigned int finfo_cnt; unsigned int buf_size; char *filepath = NULL; bool opcodes = false; bool visual = false; + char func_sig[1024]; unsigned char *buf; __u32 *member_len; __u64 *member_ptr; @@ -551,6 +557,17 @@ static int do_dump(int argc, char **argv) } } + finfo_cnt = info.func_info_cnt; + finfo_rec_size = info.func_info_rec_size; + if (finfo_cnt && finfo_rec_size) { + func_info = malloc(finfo_cnt * finfo_rec_size); + if (!func_info) { + p_err("mem alloc failed"); + close(fd); + goto err_free; + } + } + memset(&info, 0, sizeof(info)); *member_ptr = ptr_to_u64(buf); @@ -559,6 +576,9 @@ static int do_dump(int argc, char **argv) info.nr_jited_ksyms = nr_func_ksyms; info.jited_func_lens = ptr_to_u64(func_lens); info.nr_jited_func_lens = nr_func_lens; + info.func_info_cnt = finfo_cnt; + info.func_info_rec_size = finfo_rec_size; + info.func_info = ptr_to_u64(func_info); err = bpf_obj_get_info_by_fd(fd, &info, &len); close(fd); @@ -582,6 +602,18 @@ static int do_dump(int argc, char **argv) goto err_free; } + if (info.func_info_cnt != finfo_cnt) { + p_err("incorrect func_info_cnt %d vs. expected %d", + info.func_info_cnt, finfo_cnt); + goto err_free; + } + + if (info.func_info_rec_size != finfo_rec_size) { + p_err("incorrect func_info_rec_size %d vs. expected %d", + info.func_info_rec_size, finfo_rec_size); + goto err_free; + } + if ((member_len == &info.jited_prog_len && info.jited_prog_insns == 0) || (member_len == &info.xlated_prog_len && @@ -590,6 +622,11 @@ static int do_dump(int argc, char **argv) goto err_free; } + if (info.btf_id && btf_get_from_id(info.btf_id, &btf)) { + p_err("failed to get btf"); + goto err_free; + } + if (filepath) { fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600); if (fd < 0) { @@ -622,6 +659,7 @@ static int do_dump(int argc, char **argv) if (info.nr_jited_func_lens && info.jited_func_lens) { struct kernel_sym *sym = NULL; + struct bpf_func_info *record; char sym_name[SYM_MAX_NAME]; unsigned char *img = buf; __u64 *ksyms = NULL; @@ -648,12 +686,25 @@ static int do_dump(int argc, char **argv) strcpy(sym_name, "unknown"); } + if (func_info) { + record = func_info + i * finfo_rec_size; + btf_dumper_type_only(btf, record->type_id, + func_sig, + sizeof(func_sig)); + } + if (json_output) { jsonw_start_object(json_wtr); + if (func_info && func_sig[0] != '\0') { + jsonw_name(json_wtr, "proto"); + jsonw_string(json_wtr, func_sig); + } jsonw_name(json_wtr, "name"); jsonw_string(json_wtr, sym_name); jsonw_name(json_wtr, "insns"); } else { + if (func_info && func_sig[0] != '\0') + printf("%s:\n", func_sig); printf("%s:\n", sym_name); } @@ -682,6 +733,9 @@ static int do_dump(int argc, char **argv) kernel_syms_load(&dd); dd.nr_jited_ksyms = info.nr_jited_ksyms; dd.jited_ksyms = (__u64 *) info.jited_ksyms; + dd.btf = btf; + dd.func_info = func_info; + dd.finfo_rec_size = finfo_rec_size; if (json_output) dump_xlated_json(&dd, buf, *member_len, opcodes); @@ -693,12 +747,14 @@ static int do_dump(int argc, char **argv) free(buf); free(func_ksyms); free(func_lens); + free(func_info); return 0; err_free: free(buf); free(func_ksyms); free(func_lens); + free(func_info); return -1; } diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c index 3284759df98a..e06ac0286a75 100644 --- a/tools/bpf/bpftool/xlated_dumper.c +++ b/tools/bpf/bpftool/xlated_dumper.c @@ -242,11 +242,15 @@ void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len, .cb_imm = print_imm, .private_data = dd, }; + struct bpf_func_info *record; struct bpf_insn *insn = buf; + struct btf *btf = dd->btf; bool double_insn = false; + char func_sig[1024]; unsigned int i; jsonw_start_array(json_wtr); + record = dd->func_info; for (i = 0; i < len / sizeof(*insn); i++) { if (double_insn) { double_insn = false; @@ -255,6 +259,20 @@ void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len, double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW); jsonw_start_object(json_wtr); + + if (btf && record) { + if (record->insn_offset == i) { + btf_dumper_type_only(btf, record->type_id, + func_sig, + sizeof(func_sig)); + if (func_sig[0] != '\0') { + jsonw_name(json_wtr, "proto"); + jsonw_string(json_wtr, func_sig); + } + record = (void *)record + dd->finfo_rec_size; + } + } + jsonw_name(json_wtr, "disasm"); print_bpf_insn(&cbs, insn + i, true); @@ -297,16 +315,31 @@ void dump_xlated_plain(struct dump_data *dd, void *buf, unsigned int len, .cb_imm = print_imm, .private_data = dd, }; + struct bpf_func_info *record; struct bpf_insn *insn = buf; + struct btf *btf = dd->btf; bool double_insn = false; + char func_sig[1024]; unsigned int i; + record = dd->func_info; for (i = 0; i < len / sizeof(*insn); i++) { if (double_insn) { double_insn = false; continue; } + if (btf && record) { + if (record->insn_offset == i) { + btf_dumper_type_only(btf, record->type_id, + func_sig, + sizeof(func_sig)); + if (func_sig[0] != '\0') + printf("%s:\n", func_sig); + record = (void *)record + dd->finfo_rec_size; + } + } + double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW); printf("% 4d: ", i); diff --git a/tools/bpf/bpftool/xlated_dumper.h b/tools/bpf/bpftool/xlated_dumper.h index 33d86e2b369b..aec31723e1e5 100644 --- a/tools/bpf/bpftool/xlated_dumper.h +++ b/tools/bpf/bpftool/xlated_dumper.h @@ -51,6 +51,9 @@ struct dump_data { __u32 sym_count; __u64 *jited_ksyms; __u32 nr_jited_ksyms; + struct btf *btf; + void *func_info; + __u32 finfo_rec_size; char scratch_buff[SYM_MAX_NAME + 8]; };