From 2fefca057be2c4566c355551eeeee3559754e1a8 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Mon, 26 Jun 2023 13:29:01 +0800 Subject: [PATCH 01/22] bpf: btf: Break up btf_type_is_void() ANBZ: #5530 commit b47a0bd23e34022aa0d4b812fcebe85cb0c54d49 upstream. 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 Signed-off-by: Xuezhi Zhao --- 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 3e2413345e71..4dab8d3df7a4 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -307,15 +307,22 @@ 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_fwd(const struct btf_type *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_is_void_or_null(const struct btf_type *t) +static bool btf_type_nosize_or_null(const struct btf_type *t) { - return !t || btf_type_is_void(t); + return !t || btf_type_nosize(t); } /* union is only a special case of struct: @@ -851,7 +858,7 @@ 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)) { @@ -867,7 +874,7 @@ 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; } @@ -1205,7 +1212,7 @@ 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) && @@ -1219,7 +1226,7 @@ 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; } @@ -1246,7 +1253,7 @@ 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) && @@ -1276,7 +1283,7 @@ 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; } @@ -1450,7 +1457,7 @@ 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; } @@ -1469,7 +1476,7 @@ 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; @@ -1682,7 +1689,7 @@ 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; -- Gitee From 2acee0046b6fa3cba2d8e35aa9570aaa8f387063 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Mon, 26 Jun 2023 13:53:05 +0800 Subject: [PATCH 02/22] bpf: btf: Add BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO ANBZ: #5530 commit 2667a2626f4da370409c2830552f6e8c8b8c41e2 upstream. 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 Signed-off-by: Xuezhi Zhao --- include/uapi/linux/btf.h | 18 +- kernel/bpf/btf.c | 364 +++++++++++++++++++++++++++++++++------ 2 files changed, 329 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 4dab8d3df7a4..7b1cbb75bdc5 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -260,6 +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 { @@ -282,6 +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 @@ -315,9 +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) @@ -772,11 +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); @@ -1211,10 +1231,6 @@ 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); @@ -1225,13 +1241,18 @@ 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; @@ -1244,7 +1265,6 @@ 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) { @@ -1252,10 +1272,6 @@ 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); @@ -1282,13 +1298,18 @@ 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; @@ -1869,6 +1890,232 @@ 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, @@ -1881,6 +2128,8 @@ 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, @@ -1952,30 +2201,6 @@ 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) @@ -2009,6 +2234,39 @@ 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; @@ -2031,10 +2289,16 @@ 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; } } -- Gitee From 4dcb46b0eb1149715d7512be3cceaed698df7923 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Mon, 26 Jun 2023 13:55:26 +0800 Subject: [PATCH 03/22] tools/bpf: Sync kernel btf.h header ANBZ: #5530 commit 781e775e296ce3aabe0a4a0f773dccda02267695 upstream. 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 Signed-off-by: Xuezhi Zhao --- 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__ */ -- Gitee From 0be398610bf3cf57cabb1aa3c13b17eae24aae0b Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Mon, 26 Jun 2023 14:01:48 +0800 Subject: [PATCH 04/22] tools/bpf: Add tests for BTF_KIND_FUNC_PROTO and BTF_KIND_FUNC ANBZ: #5530 commit 78a2540e8945678b390a5f41eb82459bc6f0f36c upstream. 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 Signed-off-by: Xuezhi Zhao --- 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 29116366a9fc..6cbd697fe2e1 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 @@ -1734,6 +1746,464 @@ 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) -- Gitee From 0cb323557c10b0f4fcbd5b43604844bef07f6f50 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 26 Jun 2023 14:21:18 +0800 Subject: [PATCH 05/22] bpf: Introduce bpf_func_info ANBZ: #5530 commit 838e96904ff3fc6c30e5ebbc611474669856e3c0 upstream. 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 Signed-off-by: Xuezhi Zhao --- 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 10044a5661ac..baa3624ff65b 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -322,6 +322,8 @@ 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; @@ -539,7 +541,8 @@ 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 d282460e827d..e1d5276659b3 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -218,6 +218,7 @@ 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 87d9894cb0b2..cfd6d0edede2 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -340,6 +340,10 @@ 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 */ @@ -2658,6 +2662,10 @@ 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 { @@ -2969,4 +2977,9 @@ 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 7b1cbb75bdc5..c28d0609c6a1 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 965a1c18ec43..a41566d04c8a 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 @@ -389,6 +391,8 @@ 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 + @@ -403,6 +407,15 @@ 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 334763af4095..0491e6517f66 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1228,6 +1228,7 @@ 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); } @@ -1454,9 +1455,9 @@ 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; @@ -1543,7 +1544,7 @@ 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; @@ -2109,6 +2110,7 @@ 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; } @@ -2246,6 +2248,55 @@ 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)) @@ -2531,7 +2582,7 @@ 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 aa85ab6a60b7..b9982a8b9c89 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 @@ -5197,6 +5199,114 @@ 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) @@ -6510,6 +6620,9 @@ 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; @@ -6950,7 +7063,8 @@ 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; @@ -7022,6 +7136,10 @@ 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); -- Gitee From 30f3317db6ef4cf8f3f6d34fcaeebd9d2510860f Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 26 Jun 2023 14:24:26 +0800 Subject: [PATCH 06/22] tools/bpf: sync kernel uapi bpf.h header to tools directory ANBZ: #5530 commit cc19435cb2ee34a3663f0be69f3a4647795b0417 upstream. 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 Signed-off-by: Xuezhi Zhao --- 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 4b9468f09377..b06a99d9ab6d 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 */ @@ -2653,6 +2657,10 @@ 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 { @@ -2964,4 +2972,9 @@ struct bpf_flow_keys { }; }; +struct bpf_func_info { + __u32 insn_offset; + __u32 type_id; +}; + #endif /* _UAPI__LINUX_BPF_H__ */ -- Gitee From 9d710faa10271b1c50e041c0396c1b2d548cadfa Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 26 Jun 2023 14:28:22 +0800 Subject: [PATCH 07/22] tools/bpf: add new fields for program load in lib/bpf ANBZ: #5530 commit 7e0d0fb5522a388700ceff723af98c47ffa8a0a9 upstream. 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 Signed-off-by: Xuezhi Zhao --- 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 bd003cc91f94..168f296df2af 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -218,6 +218,10 @@ 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 7ddc8a2d1981..df1b1cd52fb5 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -75,6 +75,10 @@ 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 */ -- Gitee From 5d94e3fb36dbe9f046a0df44e8df117f9c9de365 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 28 Jun 2023 14:50:26 +0800 Subject: [PATCH 08/22] tools/bpf: extends test_btf to test load/retrieve func_type info ANBZ: #5530 commit 4798c4ba3ba94e4da37b2557dfda04f80a94e8d5 upstream. 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 Signed-off-by: Xuezhi Zhao --- 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 6cbd697fe2e1..10d94f7225da 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include #include @@ -21,9 +22,13 @@ #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]; @@ -3199,16 +3223,310 @@ 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) { @@ -3231,6 +3549,9 @@ 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); @@ -3284,6 +3605,8 @@ 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(); @@ -3296,8 +3619,11 @@ 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(); -- Gitee From 8394d63b7458983373e537891701d6cad31ba5e1 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 26 Jun 2023 14:54:35 +0800 Subject: [PATCH 09/22] tools/bpf: add support to read .BTF.ext sections ANBZ: #5530 commit 2993e0515bb44e157c17c9ba7309ba46366b6add upstream. 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 Signed-off-by: Xuezhi Zhao --- tools/lib/bpf/bpf.c | 47 ++++++- tools/lib/bpf/btf.c | 274 +++++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/btf.h | 50 ++++++++ tools/lib/bpf/libbpf.c | 87 ++++++++++--- 4 files changed, 443 insertions(+), 15 deletions(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 168f296df2af..fe6b67514e7f 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -199,6 +199,7 @@ 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; @@ -229,12 +230,56 @@ 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_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_prog_load(&attr, sizeof(attr)); + fd = sys_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 3403d3ee6609..47b62a1b5721 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -158,6 +158,10 @@ 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 { @@ -214,6 +218,7 @@ struct bpf_object { struct list_head list; struct btf *btf; + struct btf_ext *btf_ext; void *priv; bpf_object_clear_priv_t clear_priv; @@ -243,6 +248,9 @@ 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) @@ -317,6 +325,7 @@ 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: @@ -809,6 +818,15 @@ 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", @@ -1192,6 +1210,7 @@ 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; @@ -1214,6 +1233,20 @@ 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; @@ -1233,7 +1266,24 @@ 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++) { @@ -1321,9 +1371,9 @@ 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]; @@ -1331,14 +1381,18 @@ 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; @@ -1396,8 +1450,14 @@ 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", @@ -1419,10 +1479,9 @@ 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; @@ -1450,11 +1509,10 @@ 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", @@ -2122,6 +2180,7 @@ 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); -- Gitee From 25364a867b76877d6b3cc726f1a416aca22418d4 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 19 Nov 2018 15:29:17 -0800 Subject: [PATCH 10/22] tools/bpf: do not use pahole if clang/llvm can generate BTF sections ANBZ: #5530 commit 9ce6ae22c8e878aee7a96836b2ed9fd9a8173e41 upstream. 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 Signed-off-by: Xuezhi Zhao --- 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 1f040cee60bc..d6b9da7b5bcf 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -207,12 +207,20 @@ 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 628a56b39dbb..1b004edebd2d 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 -- Gitee From da5c67280e27cf7e6517d9de584cb02b6524d478 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 26 Jun 2023 15:17:41 +0800 Subject: [PATCH 11/22] tools/bpf: refactor to implement btf_get_from_id() in lib/bpf ANBZ: #5530 commit d7f5b5e051554c91bab995b67101af4625af591a upstream. 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 Signed-off-by: Xuezhi Zhao --- 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 51ebccdef265..40a0abec6629 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -196,70 +196,6 @@ 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); @@ -762,7 +698,7 @@ 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; @@ -906,7 +842,7 @@ 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); -- Gitee From 1e27c29fbd5ff9ae15564b21aa36ddc16b0f0d94 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 28 Jun 2023 14:53:39 +0800 Subject: [PATCH 12/22] tools/bpf: enhance test_btf file testing to test func info ANBZ: #5530 commit 999d82cbc04416cc7f2b5cb6daab947c16f0fd3a upstream. 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 Signed-off-by: Xuezhi Zhao --- 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 10d94f7225da..b026ac2d45fe 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -2794,13 +2794,13 @@ 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")) @@ -2832,14 +2832,12 @@ 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); @@ -2849,15 +2847,24 @@ 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; @@ -2885,6 +2892,7 @@ 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")) { @@ -2899,9 +2907,100 @@ 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"; -- Gitee From 39531436b1feb68681a707ca77147f8b69d4bdd4 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 26 Jun 2023 15:23:06 +0800 Subject: [PATCH 13/22] tools/bpf: bpftool: add support for func types ANBZ: #5530 commit 254471e57a86b8dc1a2cc19848e99f5d7c0558f4 upstream. 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 Signed-off-by: Xuezhi Zhao --- 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 e4e6e2b3fd84..0f1df9019dfc 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 9c7de89ccb63..7431669fae0a 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 e9edc821c9db..e0a503b1d24d 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -47,6 +47,7 @@ #include #include +#include #include #include "cfg.h" @@ -453,14 +454,19 @@ 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; @@ -553,6 +559,17 @@ 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); @@ -561,6 +578,9 @@ 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); @@ -584,6 +604,18 @@ 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 && @@ -592,6 +624,11 @@ 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) { @@ -624,6 +661,7 @@ 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; @@ -650,12 +688,25 @@ 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); } @@ -684,6 +735,9 @@ 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); @@ -695,12 +749,14 @@ 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]; }; -- Gitee From 4f1c0d85b4b4103bd6ffb673a397975cee3b99c9 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 26 Jun 2023 15:33:00 +0800 Subject: [PATCH 14/22] bpf: fix a compilation error when CONFIG_BPF_SYSCALL is not defined ANBZ: #5530 commit f6161a8f3036caa45f225486be39783e99e0fa29 upstream. Kernel test robot (lkp@intel.com) reports a compilation error at https://www.spinics.net/lists/netdev/msg534913.html introduced by commit 838e96904ff3 ("bpf: Introduce bpf_func_info"). If CONFIG_BPF is defined and CONFIG_BPF_SYSCALL is not defined, the following error will appear: kernel/bpf/core.c:414: undefined reference to `btf_type_by_id' kernel/bpf/core.c:415: undefined reference to `btf_name_by_offset' When CONFIG_BPF_SYSCALL is not defined, let us define stub inline functions for btf_type_by_id() and btf_name_by_offset() in include/linux/btf.h. This way, the compilation failure can be avoided. Fixes: 838e96904ff3 ("bpf: Introduce bpf_func_info") Reported-by: kbuild test robot Cc: Martin KaFai Lau Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Signed-off-by: Xuezhi Zhao --- include/linux/btf.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/linux/btf.h b/include/linux/btf.h index 7f2c0a4a45ea..8c2199b5d250 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -46,7 +46,21 @@ 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); + +#ifdef CONFIG_BPF_SYSCALL 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); +#else +static inline const struct btf_type *btf_type_by_id(const struct btf *btf, + u32 type_id) +{ + return NULL; +} +static inline const char *btf_name_by_offset(const struct btf *btf, + u32 offset) +{ + return NULL; +} +#endif #endif -- Gitee From 8250505307c22e22119ebfbe719710279b127726 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 26 Jun 2023 15:35:33 +0800 Subject: [PATCH 15/22] bpf: fix a libbpf loader issue ANBZ: #5530 commit 462c124c590fe633564192dbfa26e99af788a67c upstream. Commit 2993e0515bb4 ("tools/bpf: add support to read .BTF.ext sections") added support to read .BTF.ext sections from an object file, create and pass prog_btf_fd and func_info to the kernel. The program btf_fd (prog->btf_fd) is initialized to be -1 to please zclose so we do not need special handling dur prog close. Passing -1 to the kernel, however, will cause loading error. Passing btf_fd 0 to the kernel if prog->btf_fd is invalid fixed the problem. Fixes: 2993e0515bb4 ("tools/bpf: add support to read .BTF.ext sections") Reported-by: Andrey Ignatov Reported-by: Emre Cantimur Tested-by: Andrey Ignatov Signed-off-by: Yonghong Song Acked-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann Signed-off-by: Xuezhi Zhao --- tools/lib/bpf/libbpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 47b62a1b5721..4250b448a59d 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1389,7 +1389,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.license = license; load_attr.kern_version = kern_version; load_attr.prog_ifindex = prog->prog_ifindex; - load_attr.prog_btf_fd = prog->btf_fd; + load_attr.prog_btf_fd = prog->btf_fd >= 0 ? prog->btf_fd : 0; 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; -- Gitee From 939c68a317b80c89aa4a8f96d7c21133d99c727c Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 26 Jun 2023 15:55:42 +0800 Subject: [PATCH 16/22] bpf: btf: support proper non-jit func info ANBZ: #5530 commit ba64e7d8525236aa56ab58ba3a3a71615c4ee289 upstream. Commit 838e96904ff3 ("bpf: Introduce bpf_func_info") added bpf func info support. The userspace is able to get better ksym's for bpf programs with jit, and is able to print out func prototypes. For a program containing func-to-func calls, the existing implementation returns user specified number of function calls and BTF types if jit is enabled. If the jit is not enabled, it only returns the type for the main function. This is undesirable. Interpreter may still be used and we should keep feature identical regardless of whether jit is enabled or not. This patch fixed this discrepancy. Fixes: 838e96904ff3 ("bpf: Introduce bpf_func_info") Signed-off-by: Yonghong Song Acked-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov Signed-off-by: Xuezhi Zhao --- include/linux/bpf.h | 6 ++-- include/linux/bpf_verifier.h | 1 - kernel/bpf/core.c | 3 +- kernel/bpf/syscall.c | 33 ++++++---------------- kernel/bpf/verifier.c | 55 +++++++++++++++++++++++++----------- 5 files changed, 52 insertions(+), 46 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index baa3624ff65b..1731c462615d 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -305,7 +305,8 @@ struct bpf_prog_aux { u32 max_pkt_offset; u32 stack_depth; u32 id; - u32 func_cnt; + u32 func_cnt; /* used by non-func prog as the number of func progs */ + u32 func_idx; /* 0 for non-func prog, the index in func array for func prog */ bool offload_requested; struct bpf_prog **func; void *jit_data; /* JIT specific data. arch dependent */ @@ -323,7 +324,8 @@ struct bpf_prog_aux { #endif struct bpf_prog_offload *offload; struct btf *btf; - u32 type_id; /* type id for this prog/func */ + struct bpf_func_info *func_info; + u32 func_info_cnt; union { struct work_struct work; struct rcu_head rcu; diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index e1d5276659b3..d282460e827d 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -218,7 +218,6 @@ 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/kernel/bpf/core.c b/kernel/bpf/core.c index a41566d04c8a..5e84933d7ad6 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -410,7 +410,8 @@ static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) /* 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); + type = btf_type_by_id(prog->aux->btf, + prog->aux->func_info[prog->aux->func_idx].type_id); func_name = btf_name_by_offset(prog->aux->btf, type->name_off); snprintf(sym, (size_t)(end - sym), "_%s", func_name); return; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 0491e6517f66..f3c8e414eaaf 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1229,6 +1229,7 @@ static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock) bpf_prog_free_id(prog, do_idr_lock); bpf_prog_kallsyms_del_all(prog); btf_put(prog->aux->btf); + kvfree(prog->aux->func_info); call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); } @@ -2249,46 +2250,28 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, } if (prog->aux->btf) { + u32 krec_size = sizeof(struct bpf_func_info); 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; + info.func_info_cnt = prog->aux->func_info_cnt; urec_size = info.func_info_rec_size; - info.func_info_rec_size = sizeof(struct bpf_func_info); + info.func_info_rec_size = krec_size; 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; - } + ucnt = min_t(u32, info.func_info_cnt, ucnt); + if (copy_to_user(user_finfo, prog->aux->func_info, + krec_size * ucnt)) + return -EFAULT; } else { info.func_info_cnt = 0; } diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index b9982a8b9c89..d9bea2d4ced3 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5208,7 +5208,7 @@ static int check_btf_func(struct bpf_prog *prog, struct bpf_verifier_env *env, { u32 i, nfuncs, urec_size, min_size, prev_offset; u32 krec_size = sizeof(struct bpf_func_info); - struct bpf_func_info krecord = {}; + struct bpf_func_info *krecord = NULL; const struct btf_type *type; void __user *urecord; struct btf *btf; @@ -5240,6 +5240,12 @@ static int check_btf_func(struct bpf_prog *prog, struct bpf_verifier_env *env, urecord = u64_to_user_ptr(attr->func_info); min_size = min_t(u32, krec_size, urec_size); + krecord = kvcalloc(nfuncs, krec_size, GFP_KERNEL | __GFP_NOWARN); + if (!krecord) { + ret = -ENOMEM; + goto free_btf; + } + for (i = 0; i < nfuncs; i++) { ret = bpf_check_uarg_tail_zero(urecord, krec_size, urec_size); if (ret) { @@ -5254,59 +5260,69 @@ static int check_btf_func(struct bpf_prog *prog, struct bpf_verifier_env *env, goto free_btf; } - if (copy_from_user(&krecord, urecord, min_size)) { + if (copy_from_user(&krecord[i], urecord, min_size)) { ret = -EFAULT; goto free_btf; } /* check insn_offset */ if (i == 0) { - if (krecord.insn_offset) { + if (krecord[i].insn_offset) { verbose(env, "nonzero insn_offset %u for the first func info record", - krecord.insn_offset); + krecord[i].insn_offset); ret = -EINVAL; goto free_btf; } - } else if (krecord.insn_offset <= prev_offset) { + } else if (krecord[i].insn_offset <= prev_offset) { verbose(env, "same or smaller insn offset (%u) than previous func info record (%u)", - krecord.insn_offset, prev_offset); + krecord[i].insn_offset, prev_offset); ret = -EINVAL; goto free_btf; } - if (env->subprog_info[i].start != krecord.insn_offset) { + if (env->subprog_info[i].start != krecord[i].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); + type = btf_type_by_id(btf, krecord[i].type_id); if (!type || BTF_INFO_KIND(type->info) != BTF_KIND_FUNC) { verbose(env, "invalid type id %d in func info", - krecord.type_id); + krecord[i].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; + prev_offset = krecord[i].insn_offset; urecord += urec_size; } prog->aux->btf = btf; + prog->aux->func_info = krecord; + prog->aux->func_info_cnt = nfuncs; return 0; free_btf: btf_put(btf); + kvfree(krecord); return ret; } +static void adjust_btf_func(struct bpf_verifier_env *env) +{ + int i; + + if (!env->prog->aux->func_info) + return; + + for (i = 0; i < env->subprog_cnt; i++) + env->prog->aux->func_info[i].insn_offset = env->subprog_info[i].start; +} + /* check %cur's range satisfies %old's */ static bool range_within(struct bpf_reg_state *old, struct bpf_reg_state *cur) @@ -6614,15 +6630,17 @@ static int jit_subprogs(struct bpf_verifier_env *env) if (bpf_prog_calc_tag(func[i])) goto out_free; func[i]->is_func = 1; + func[i]->aux->func_idx = i; + /* the btf and func_info will be freed only at prog->aux */ + func[i]->aux->btf = prog->aux->btf; + func[i]->aux->func_info = prog->aux->func_info; + /* Use bpf_prog_F_tag to indicate functions in stack traces. * Long term would need debug info to populate names */ 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; @@ -7197,6 +7215,9 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, convert_pseudo_ld_imm64(env); } + if (ret == 0) + adjust_btf_func(env); + err_release_maps: if (!env->prog->aux->used_maps) /* if we didn't copy map pointers into bpf_prog_info, release -- Gitee From ad367c5fa229bfdc8cd4a3ec98e76f363d20e5f2 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 28 Jun 2023 15:16:27 +0800 Subject: [PATCH 17/22] tools/bpf: change selftest test_btf for both jit and non-jit ANBZ: #5530 commit 812dd689da2a9af1208449588e4529c89a9d661d upstream. The selftest test_btf is changed to test both jit and non-jit. The test result should be the same regardless of whether jit is enabled or not. Signed-off-by: Yonghong Song Acked-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov Signed-off-by: Xuezhi Zhao --- tools/testing/selftests/bpf/test_btf.c | 33 +++----------------------- 1 file changed, 3 insertions(+), 30 deletions(-) diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index b026ac2d45fe..3f330f4c4c23 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -28,7 +28,6 @@ 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); \ @@ -65,24 +64,6 @@ 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)) @@ -2907,8 +2888,8 @@ static int do_test_file(unsigned int test_num) test->btf_kv_notfound)) goto done; - if (!jit_enabled || !has_btf_ext) - goto skip_jit; + if (!has_btf_ext) + goto skip; /* get necessary program info */ info_len = sizeof(struct bpf_prog_info); @@ -2996,7 +2977,7 @@ static int do_test_file(unsigned int test_num) finfo = (void *)finfo + rec_size; } -skip_jit: +skip: fprintf(stderr, "OK"); done: @@ -3522,12 +3503,6 @@ static int do_test_func_type(int test_num) 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); @@ -3704,8 +3679,6 @@ 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(); -- Gitee From 043653c3929f48f0879c7426e47ca924394c7b23 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Mon, 26 Jun 2023 16:05:21 +0800 Subject: [PATCH 18/22] bpf: Fix memleak in aux->func_info and aux->btf ANBZ: #5530 commit 5482e9a93c83839f94e75db712e6837e6a39962c upstream. The aux->func_info and aux->btf are leaked in the error out cases during bpf_prog_load(). This patch fixes it. Fixes: ba64e7d85252 ("bpf: btf: support proper non-jit func info") Cc: Yonghong Song Signed-off-by: Martin KaFai Lau Acked-by: Yonghong Song Signed-off-by: Alexei Starovoitov Signed-off-by: Xuezhi Zhao --- kernel/bpf/syscall.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index f3c8e414eaaf..577ae92cfc43 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1579,6 +1579,8 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) return err; free_used_maps: + kvfree(prog->aux->func_info); + btf_put(prog->aux->btf); bpf_prog_kallsyms_del_subprogs(prog); free_used_maps(prog->aux); free_prog: -- Gitee From f268f565ad95a8e48d17985588a41cc43f968e07 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Mon, 26 Jun 2023 16:12:33 +0800 Subject: [PATCH 19/22] pf: Improve the info.func_info and info.func_info_rec_size behavior ANBZ: #5530 commit 7337224fc150b3b762190425399ac0e8dee380d1 upstream. 1) When bpf_dump_raw_ok() == false and the kernel can provide >=1 func_info to the userspace, the current behavior is setting the info.func_info_cnt to 0 instead of setting info.func_info to 0. It is different from the behavior in jited_func_lens/nr_jited_func_lens, jited_ksyms/nr_jited_ksyms...etc. This patch fixes it. (i.e. set func_info to 0 instead of func_info_cnt to 0 when bpf_dump_raw_ok() == false). 2) When the userspace passed in info.func_info_cnt == 0, the kernel will set the expected func_info size back to the info.func_info_rec_size. It is a way for the userspace to learn the kernel expected func_info_rec_size introduced in commit 838e96904ff3 ("bpf: Introduce bpf_func_info"). An exception is the kernel expected size is not set when func_info is not available for a bpf_prog. This makes the returned info.func_info_rec_size has different values depending on the returned value of info.func_info_cnt. This patch sets the kernel expected size to info.func_info_rec_size independent of the info.func_info_cnt. 3) The current logic only rejects invalid func_info_rec_size if func_info_cnt is non zero. This patch also rejects invalid nonzero info.func_info_rec_size and not equal to the kernel expected size. 4) Set info.btf_id as long as prog->aux->btf != NULL. That will setup the later copy_to_user() codes look the same as others which then easier to understand and maintain. prog->aux->btf is not NULL only if prog->aux->func_info_cnt > 0. Breaking up info.btf_id from prog->aux->func_info_cnt is needed for the later line info patch anyway. A similar change is made to bpf_get_prog_name(). Fixes: 838e96904ff3 ("bpf: Introduce bpf_func_info") Signed-off-by: Martin KaFai Lau Acked-by: Yonghong Song Signed-off-by: Alexei Starovoitov Signed-off-by: Xuezhi Zhao --- kernel/bpf/core.c | 2 +- kernel/bpf/syscall.c | 46 +++++++++++++++++++------------------------- 2 files changed, 21 insertions(+), 27 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 5e84933d7ad6..97363231d444 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -409,7 +409,7 @@ static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); /* prog->aux->name will be ignored if full btf name is available */ - if (prog->aux->btf) { + if (prog->aux->func_info_cnt) { type = btf_type_by_id(prog->aux->btf, prog->aux->func_info[prog->aux->func_idx].type_id); func_name = btf_name_by_offset(prog->aux->btf, type->name_off); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 577ae92cfc43..092d3293521b 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2108,6 +2108,12 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, return -EFAULT; } + if ((info.func_info_cnt || info.func_info_rec_size) && + info.func_info_rec_size != sizeof(struct bpf_func_info)) + return -EINVAL; + + info.func_info_rec_size = sizeof(struct bpf_func_info); + if (!capable(CAP_SYS_ADMIN)) { info.jited_prog_len = 0; info.xlated_prog_len = 0; @@ -2251,35 +2257,23 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, } } - if (prog->aux->btf) { - u32 krec_size = sizeof(struct bpf_func_info); - u32 ucnt, urec_size; - + if (prog->aux->btf) info.btf_id = btf_id(prog->aux->btf); - ucnt = info.func_info_cnt; - info.func_info_cnt = prog->aux->func_info_cnt; - urec_size = info.func_info_rec_size; - info.func_info_rec_size = krec_size; - 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()) { - char __user *user_finfo; - - user_finfo = u64_to_user_ptr(info.func_info); - ucnt = min_t(u32, info.func_info_cnt, ucnt); - if (copy_to_user(user_finfo, prog->aux->func_info, - krec_size * ucnt)) - return -EFAULT; - } else { - info.func_info_cnt = 0; - } + ulen = info.func_info_cnt; + info.func_info_cnt = prog->aux->func_info_cnt; + if (info.func_info_cnt && ulen) { + if (bpf_dump_raw_ok()) { + char __user *user_finfo; + + user_finfo = u64_to_user_ptr(info.func_info); + ulen = min_t(u32, info.func_info_cnt, ulen); + if (copy_to_user(user_finfo, prog->aux->func_info, + info.func_info_rec_size * ulen)) + return -EFAULT; + } else { + info.func_info = 0; } - } else { - info.func_info_cnt = 0; } done: -- Gitee From e63bec62461306c49c1f13d962c3da42ad7ee027 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 26 Jun 2023 16:22:38 +0800 Subject: [PATCH 20/22] bpf: btf: allow typedef func_proto ANBZ: #5530 commit 81f5c6f5db37bf2360b64c304b27b8f499b48367 upstream. Current implementation does not allow typedef func_proto. But it is actually allowed. -bash-4.4$ cat t.c typedef int (f) (int); f *g; -bash-4.4$ clang -O2 -g -c -target bpf t.c -Xclang -target-feature -Xclang +dwarfris -bash-4.4$ pahole -JV t.o File t.o: [1] PTR (anon) type_id=2 [2] TYPEDEF f type_id=3 [3] FUNC_PROTO (anon) return=4 args=(4 (anon)) [4] INT int size=4 bit_offset=0 nr_bits=32 encoding=SIGNED -bash-4.4$ This patch related btf verifier to allow such (typedef func_proto) patterns. Fixes: 2667a2626f4d ("bpf: btf: Add BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO") Acked-by: Martin KaFai Lau Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Signed-off-by: Xuezhi Zhao --- kernel/bpf/btf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index c28d0609c6a1..d122c7d2f905 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -1247,7 +1247,8 @@ static int btf_modifier_resolve(struct btf_verifier_env *env, /* "typedef void new_void", "const void"...etc */ if (!btf_type_is_void(next_type) && - !btf_type_is_fwd(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; } -- Gitee From 4e2be41252ac8bde2355ec57e106eb61620bc18d Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 26 Jun 2023 16:26:52 +0800 Subject: [PATCH 21/22] tools/bpf: fix test_btf for typedef func_proto case ANBZ: #5530 commit 32b750b925040565bbeff1fe2f7510e3dc71ce2e upstream. Fixed one test_btf raw test such that typedef func_proto is permitted now. Fixes: 78a2540e8945 ("tools/bpf: Add tests for BTF_KIND_FUNC_PROTO and BTF_KIND_FUNC") Acked-by: Martin KaFai Lau Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Signed-off-by: Xuezhi Zhao --- tools/testing/selftests/bpf/test_btf.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index 3f330f4c4c23..6136e95953a0 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -1873,13 +1873,12 @@ static struct btf_raw_test raw_tests[] = { }, { - .descr = "func proto (CONST=>TYPEDEF=>FUNC_PROTO)", + .descr = "func proto (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_TYPEDEF_ENC(NAME_TBD, 4), /* [3] */ + BTF_FUNC_PROTO_ENC(0, 2), /* [4] */ BTF_FUNC_PROTO_ARG_ENC(0, 1), BTF_FUNC_PROTO_ARG_ENC(0, 2), BTF_END_RAW, @@ -1893,8 +1892,6 @@ static struct btf_raw_test raw_tests[] = { .key_type_id = 1, .value_type_id = 1, .max_entries = 4, - .btf_load_err = true, - .err_str = "Invalid type_id", }, { -- Gitee From dc268915f42e102ed39dc14cd92d810e610749d3 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 26 Jun 2023 16:42:11 +0800 Subject: [PATCH 22/22] libbpf: Fix memory leak/double free issue ANBZ: #5530 commit 3dc5e059821376974177cc801d377e3fcdac6712 upstream. Coverity scan against Github libbpf code found the issue of not freeing memory and leaving already freed memory still referenced from bpf_program. Fix it by re-assigning successfully reallocated memory sooner. Fixes: 2993e0515bb4 ("tools/bpf: add support to read .BTF.ext sections") Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20191107020855.3834758-2-andriin@fb.com Signed-off-by: Xuezhi Zhao --- tools/lib/bpf/libbpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 4250b448a59d..841997c176a0 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1233,6 +1233,7 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj, pr_warning("oom in prog realloc\n"); return -ENOMEM; } + prog->insns = new_insn; if (obj->btf && obj->btf_ext) { err = btf_ext__reloc(obj->btf, obj->btf_ext, @@ -1249,7 +1250,6 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj, memcpy(new_insn + prog->insns_cnt, text->insns, text->insns_cnt * sizeof(*insn)); - prog->insns = new_insn; prog->main_prog_cnt = prog->insns_cnt; prog->insns_cnt = new_cnt; pr_debug("added %zd insn from %s to prog %s\n", -- Gitee