// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) /* * BTF-to-C type converter. * * Copyright (c) 2019 Facebook */ #include <stdbool.h> #include <stddef.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <linux/err.h> #include <linux/btf.h> #include <linux/kernel.h> #include "btf.h" #include "hashmap.h" #include "libbpf.h" #include "libbpf_internal.h" static const char PREFIXES[] = "\t\t\t\t\t\t\t\t\t\t\t\t\t"; static const size_t PREFIX_CNT = sizeof(PREFIXES) - 1; static const char *pfx(int lvl) { <------>return lvl >= PREFIX_CNT ? PREFIXES : &PREFIXES[PREFIX_CNT - lvl]; } enum btf_dump_type_order_state { <------>NOT_ORDERED, <------>ORDERING, <------>ORDERED, }; enum btf_dump_type_emit_state { <------>NOT_EMITTED, <------>EMITTING, <------>EMITTED, }; /* per-type auxiliary state */ struct btf_dump_type_aux_state { <------>/* topological sorting state */ <------>enum btf_dump_type_order_state order_state: 2; <------>/* emitting state used to determine the need for forward declaration */ <------>enum btf_dump_type_emit_state emit_state: 2; <------>/* whether forward declaration was already emitted */ <------>__u8 fwd_emitted: 1; <------>/* whether unique non-duplicate name was already assigned */ <------>__u8 name_resolved: 1; <------>/* whether type is referenced from any other type */ <------>__u8 referenced: 1; }; struct btf_dump { <------>const struct btf *btf; <------>const struct btf_ext *btf_ext; <------>btf_dump_printf_fn_t printf_fn; <------>struct btf_dump_opts opts; <------>int ptr_sz; <------>bool strip_mods; <------>int last_id; <------>/* per-type auxiliary state */ <------>struct btf_dump_type_aux_state *type_states; <------>size_t type_states_cap; <------>/* per-type optional cached unique name, must be freed, if present */ <------>const char **cached_names; <------>size_t cached_names_cap; <------>/* topo-sorted list of dependent type definitions */ <------>__u32 *emit_queue; <------>int emit_queue_cap; <------>int emit_queue_cnt; <------>/* <------> * stack of type declarations (e.g., chain of modifiers, arrays, <------> * funcs, etc) <------> */ <------>__u32 *decl_stack; <------>int decl_stack_cap; <------>int decl_stack_cnt; <------>/* maps struct/union/enum name to a number of name occurrences */ <------>struct hashmap *type_names; <------>/* <------> * maps typedef identifiers and enum value names to a number of such <------> * name occurrences <------> */ <------>struct hashmap *ident_names; }; static size_t str_hash_fn(const void *key, void *ctx) { <------>return str_hash(key); } static bool str_equal_fn(const void *a, const void *b, void *ctx) { <------>return strcmp(a, b) == 0; } static const char *btf_name_of(const struct btf_dump *d, __u32 name_off) { <------>return btf__name_by_offset(d->btf, name_off); } static void btf_dump_printf(const struct btf_dump *d, const char *fmt, ...) { <------>va_list args; <------>va_start(args, fmt); <------>d->printf_fn(d->opts.ctx, fmt, args); <------>va_end(args); } static int btf_dump_mark_referenced(struct btf_dump *d); static int btf_dump_resize(struct btf_dump *d); struct btf_dump *btf_dump__new(const struct btf *btf, <------><------><------> const struct btf_ext *btf_ext, <------><------><------> const struct btf_dump_opts *opts, <------><------><------> btf_dump_printf_fn_t printf_fn) { <------>struct btf_dump *d; <------>int err; <------>d = calloc(1, sizeof(struct btf_dump)); <------>if (!d) <------><------>return ERR_PTR(-ENOMEM); <------>d->btf = btf; <------>d->btf_ext = btf_ext; <------>d->printf_fn = printf_fn; <------>d->opts.ctx = opts ? opts->ctx : NULL; <------>d->ptr_sz = btf__pointer_size(btf) ? : sizeof(void *); <------>d->type_names = hashmap__new(str_hash_fn, str_equal_fn, NULL); <------>if (IS_ERR(d->type_names)) { <------><------>err = PTR_ERR(d->type_names); <------><------>d->type_names = NULL; <------><------>goto err; <------>} <------>d->ident_names = hashmap__new(str_hash_fn, str_equal_fn, NULL); <------>if (IS_ERR(d->ident_names)) { <------><------>err = PTR_ERR(d->ident_names); <------><------>d->ident_names = NULL; <------><------>goto err; <------>} <------>err = btf_dump_resize(d); <------>if (err) <------><------>goto err; <------>return d; err: <------>btf_dump__free(d); <------>return ERR_PTR(err); } static int btf_dump_resize(struct btf_dump *d) { <------>int err, last_id = btf__get_nr_types(d->btf); <------>if (last_id <= d->last_id) <------><------>return 0; <------>if (btf_ensure_mem((void **)&d->type_states, &d->type_states_cap, <------><------><------> sizeof(*d->type_states), last_id + 1)) <------><------>return -ENOMEM; <------>if (btf_ensure_mem((void **)&d->cached_names, &d->cached_names_cap, <------><------><------> sizeof(*d->cached_names), last_id + 1)) <------><------>return -ENOMEM; <------>if (d->last_id == 0) { <------><------>/* VOID is special */ <------><------>d->type_states[0].order_state = ORDERED; <------><------>d->type_states[0].emit_state = EMITTED; <------>} <------>/* eagerly determine referenced types for anon enums */ <------>err = btf_dump_mark_referenced(d); <------>if (err) <------><------>return err; <------>d->last_id = last_id; <------>return 0; } void btf_dump__free(struct btf_dump *d) { <------>int i; <------>if (IS_ERR_OR_NULL(d)) <------><------>return; <------>free(d->type_states); <------>if (d->cached_names) { <------><------>/* any set cached name is owned by us and should be freed */ <------><------>for (i = 0; i <= d->last_id; i++) { <------><------><------>if (d->cached_names[i]) <------><------><------><------>free((void *)d->cached_names[i]); <------><------>} <------>} <------>free(d->cached_names); <------>free(d->emit_queue); <------>free(d->decl_stack); <------>hashmap__free(d->type_names); <------>hashmap__free(d->ident_names); <------>free(d); } static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr); static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id); /* * Dump BTF type in a compilable C syntax, including all the necessary * dependent types, necessary for compilation. If some of the dependent types * were already emitted as part of previous btf_dump__dump_type() invocation * for another type, they won't be emitted again. This API allows callers to * filter out BTF types according to user-defined criterias and emitted only * minimal subset of types, necessary to compile everything. Full struct/union * definitions will still be emitted, even if the only usage is through * pointer and could be satisfied with just a forward declaration. * * Dumping is done in two high-level passes: * 1. Topologically sort type definitions to satisfy C rules of compilation. * 2. Emit type definitions in C syntax. * * Returns 0 on success; <0, otherwise. */ int btf_dump__dump_type(struct btf_dump *d, __u32 id) { <------>int err, i; <------>if (id > btf__get_nr_types(d->btf)) <------><------>return -EINVAL; <------>err = btf_dump_resize(d); <------>if (err) <------><------>return err; <------>d->emit_queue_cnt = 0; <------>err = btf_dump_order_type(d, id, false); <------>if (err < 0) <------><------>return err; <------>for (i = 0; i < d->emit_queue_cnt; i++) <------><------>btf_dump_emit_type(d, d->emit_queue[i], 0 /*top-level*/); <------>return 0; } /* * Mark all types that are referenced from any other type. This is used to * determine top-level anonymous enums that need to be emitted as an * independent type declarations. * Anonymous enums come in two flavors: either embedded in a struct's field * definition, in which case they have to be declared inline as part of field * type declaration; or as a top-level anonymous enum, typically used for * declaring global constants. It's impossible to distinguish between two * without knowning whether given enum type was referenced from other type: * top-level anonymous enum won't be referenced by anything, while embedded * one will. */ static int btf_dump_mark_referenced(struct btf_dump *d) { <------>int i, j, n = btf__get_nr_types(d->btf); <------>const struct btf_type *t; <------>__u16 vlen; <------>for (i = d->last_id + 1; i <= n; i++) { <------><------>t = btf__type_by_id(d->btf, i); <------><------>vlen = btf_vlen(t); <------><------>switch (btf_kind(t)) { <------><------>case BTF_KIND_INT: <------><------>case BTF_KIND_ENUM: <------><------>case BTF_KIND_FWD: <------><------><------>break; <------><------>case BTF_KIND_VOLATILE: <------><------>case BTF_KIND_CONST: <------><------>case BTF_KIND_RESTRICT: <------><------>case BTF_KIND_PTR: <------><------>case BTF_KIND_TYPEDEF: <------><------>case BTF_KIND_FUNC: <------><------>case BTF_KIND_VAR: <------><------><------>d->type_states[t->type].referenced = 1; <------><------><------>break; <------><------>case BTF_KIND_ARRAY: { <------><------><------>const struct btf_array *a = btf_array(t); <------><------><------>d->type_states[a->index_type].referenced = 1; <------><------><------>d->type_states[a->type].referenced = 1; <------><------><------>break; <------><------>} <------><------>case BTF_KIND_STRUCT: <------><------>case BTF_KIND_UNION: { <------><------><------>const struct btf_member *m = btf_members(t); <------><------><------>for (j = 0; j < vlen; j++, m++) <------><------><------><------>d->type_states[m->type].referenced = 1; <------><------><------>break; <------><------>} <------><------>case BTF_KIND_FUNC_PROTO: { <------><------><------>const struct btf_param *p = btf_params(t); <------><------><------>for (j = 0; j < vlen; j++, p++) <------><------><------><------>d->type_states[p->type].referenced = 1; <------><------><------>break; <------><------>} <------><------>case BTF_KIND_DATASEC: { <------><------><------>const struct btf_var_secinfo *v = btf_var_secinfos(t); <------><------><------>for (j = 0; j < vlen; j++, v++) <------><------><------><------>d->type_states[v->type].referenced = 1; <------><------><------>break; <------><------>} <------><------>default: <------><------><------>return -EINVAL; <------><------>} <------>} <------>return 0; } static int btf_dump_add_emit_queue_id(struct btf_dump *d, __u32 id) { <------>__u32 *new_queue; <------>size_t new_cap; <------>if (d->emit_queue_cnt >= d->emit_queue_cap) { <------><------>new_cap = max(16, d->emit_queue_cap * 3 / 2); <------><------>new_queue = libbpf_reallocarray(d->emit_queue, new_cap, sizeof(new_queue[0])); <------><------>if (!new_queue) <------><------><------>return -ENOMEM; <------><------>d->emit_queue = new_queue; <------><------>d->emit_queue_cap = new_cap; <------>} <------>d->emit_queue[d->emit_queue_cnt++] = id; <------>return 0; } /* * Determine order of emitting dependent types and specified type to satisfy * C compilation rules. This is done through topological sorting with an * additional complication which comes from C rules. The main idea for C is * that if some type is "embedded" into a struct/union, it's size needs to be * known at the time of definition of containing type. E.g., for: * * struct A {}; * struct B { struct A x; } * * struct A *HAS* to be defined before struct B, because it's "embedded", * i.e., it is part of struct B layout. But in the following case: * * struct A; * struct B { struct A *x; } * struct A {}; * * it's enough to just have a forward declaration of struct A at the time of * struct B definition, as struct B has a pointer to struct A, so the size of * field x is known without knowing struct A size: it's sizeof(void *). * * Unfortunately, there are some trickier cases we need to handle, e.g.: * * struct A {}; // if this was forward-declaration: compilation error * struct B { * struct { // anonymous struct * struct A y; * } *x; * }; * * In this case, struct B's field x is a pointer, so it's size is known * regardless of the size of (anonymous) struct it points to. But because this * struct is anonymous and thus defined inline inside struct B, *and* it * embeds struct A, compiler requires full definition of struct A to be known * before struct B can be defined. This creates a transitive dependency * between struct A and struct B. If struct A was forward-declared before * struct B definition and fully defined after struct B definition, that would * trigger compilation error. * * All this means that while we are doing topological sorting on BTF type * graph, we need to determine relationships between different types (graph * nodes): * - weak link (relationship) between X and Y, if Y *CAN* be * forward-declared at the point of X definition; * - strong link, if Y *HAS* to be fully-defined before X can be defined. * * The rule is as follows. Given a chain of BTF types from X to Y, if there is * BTF_KIND_PTR type in the chain and at least one non-anonymous type * Z (excluding X, including Y), then link is weak. Otherwise, it's strong. * Weak/strong relationship is determined recursively during DFS traversal and * is returned as a result from btf_dump_order_type(). * * btf_dump_order_type() is trying to avoid unnecessary forward declarations, * but it is not guaranteeing that no extraneous forward declarations will be * emitted. * * To avoid extra work, algorithm marks some of BTF types as ORDERED, when * it's done with them, but not for all (e.g., VOLATILE, CONST, RESTRICT, * ARRAY, FUNC_PROTO), as weak/strong semantics for those depends on the * entire graph path, so depending where from one came to that BTF type, it * might cause weak or strong ordering. For types like STRUCT/UNION/INT/ENUM, * once they are processed, there is no need to do it again, so they are * marked as ORDERED. We can mark PTR as ORDERED as well, as it semi-forces * weak link, unless subsequent referenced STRUCT/UNION/ENUM is anonymous. But * in any case, once those are processed, no need to do it again, as the * result won't change. * * Returns: * - 1, if type is part of strong link (so there is strong topological * ordering requirements); * - 0, if type is part of weak link (so can be satisfied through forward * declaration); * - <0, on error (e.g., unsatisfiable type loop detected). */ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr) { <------>/* <------> * Order state is used to detect strong link cycles, but only for BTF <------> * kinds that are or could be an independent definition (i.e., <------> * stand-alone fwd decl, enum, typedef, struct, union). Ptrs, arrays, <------> * func_protos, modifiers are just means to get to these definitions. <------> * Int/void don't need definitions, they are assumed to be always <------> * properly defined. We also ignore datasec, var, and funcs for now. <------> * So for all non-defining kinds, we never even set ordering state, <------> * for defining kinds we set ORDERING and subsequently ORDERED if it <------> * forms a strong link. <------> */ <------>struct btf_dump_type_aux_state *tstate = &d->type_states[id]; <------>const struct btf_type *t; <------>__u16 vlen; <------>int err, i; <------>/* return true, letting typedefs know that it's ok to be emitted */ <------>if (tstate->order_state == ORDERED) <------><------>return 1; <------>t = btf__type_by_id(d->btf, id); <------>if (tstate->order_state == ORDERING) { <------><------>/* type loop, but resolvable through fwd declaration */ <------><------>if (btf_is_composite(t) && through_ptr && t->name_off != 0) <------><------><------>return 0; <------><------>pr_warn("unsatisfiable type cycle, id:[%u]\n", id); <------><------>return -ELOOP; <------>} <------>switch (btf_kind(t)) { <------>case BTF_KIND_INT: <------><------>tstate->order_state = ORDERED; <------><------>return 0; <------>case BTF_KIND_PTR: <------><------>err = btf_dump_order_type(d, t->type, true); <------><------>tstate->order_state = ORDERED; <------><------>return err; <------>case BTF_KIND_ARRAY: <------><------>return btf_dump_order_type(d, btf_array(t)->type, false); <------>case BTF_KIND_STRUCT: <------>case BTF_KIND_UNION: { <------><------>const struct btf_member *m = btf_members(t); <------><------>/* <------><------> * struct/union is part of strong link, only if it's embedded <------><------> * (so no ptr in a path) or it's anonymous (so has to be <------><------> * defined inline, even if declared through ptr) <------><------> */ <------><------>if (through_ptr && t->name_off != 0) <------><------><------>return 0; <------><------>tstate->order_state = ORDERING; <------><------>vlen = btf_vlen(t); <------><------>for (i = 0; i < vlen; i++, m++) { <------><------><------>err = btf_dump_order_type(d, m->type, false); <------><------><------>if (err < 0) <------><------><------><------>return err; <------><------>} <------><------>if (t->name_off != 0) { <------><------><------>err = btf_dump_add_emit_queue_id(d, id); <------><------><------>if (err < 0) <------><------><------><------>return err; <------><------>} <------><------>tstate->order_state = ORDERED; <------><------>return 1; <------>} <------>case BTF_KIND_ENUM: <------>case BTF_KIND_FWD: <------><------>/* <------><------> * non-anonymous or non-referenced enums are top-level <------><------> * declarations and should be emitted. Same logic can be <------><------> * applied to FWDs, it won't hurt anyways. <------><------> */ <------><------>if (t->name_off != 0 || !tstate->referenced) { <------><------><------>err = btf_dump_add_emit_queue_id(d, id); <------><------><------>if (err) <------><------><------><------>return err; <------><------>} <------><------>tstate->order_state = ORDERED; <------><------>return 1; <------>case BTF_KIND_TYPEDEF: { <------><------>int is_strong; <------><------>is_strong = btf_dump_order_type(d, t->type, through_ptr); <------><------>if (is_strong < 0) <------><------><------>return is_strong; <------><------>/* typedef is similar to struct/union w.r.t. fwd-decls */ <------><------>if (through_ptr && !is_strong) <------><------><------>return 0; <------><------>/* typedef is always a named definition */ <------><------>err = btf_dump_add_emit_queue_id(d, id); <------><------>if (err) <------><------><------>return err; <------><------>d->type_states[id].order_state = ORDERED; <------><------>return 1; <------>} <------>case BTF_KIND_VOLATILE: <------>case BTF_KIND_CONST: <------>case BTF_KIND_RESTRICT: <------><------>return btf_dump_order_type(d, t->type, through_ptr); <------>case BTF_KIND_FUNC_PROTO: { <------><------>const struct btf_param *p = btf_params(t); <------><------>bool is_strong; <------><------>err = btf_dump_order_type(d, t->type, through_ptr); <------><------>if (err < 0) <------><------><------>return err; <------><------>is_strong = err > 0; <------><------>vlen = btf_vlen(t); <------><------>for (i = 0; i < vlen; i++, p++) { <------><------><------>err = btf_dump_order_type(d, p->type, through_ptr); <------><------><------>if (err < 0) <------><------><------><------>return err; <------><------><------>if (err > 0) <------><------><------><------>is_strong = true; <------><------>} <------><------>return is_strong; <------>} <------>case BTF_KIND_FUNC: <------>case BTF_KIND_VAR: <------>case BTF_KIND_DATASEC: <------><------>d->type_states[id].order_state = ORDERED; <------><------>return 0; <------>default: <------><------>return -EINVAL; <------>} } static void btf_dump_emit_missing_aliases(struct btf_dump *d, __u32 id, <------><------><------><------><------> const struct btf_type *t); static void btf_dump_emit_struct_fwd(struct btf_dump *d, __u32 id, <------><------><------><------> const struct btf_type *t); static void btf_dump_emit_struct_def(struct btf_dump *d, __u32 id, <------><------><------><------> const struct btf_type *t, int lvl); static void btf_dump_emit_enum_fwd(struct btf_dump *d, __u32 id, <------><------><------><------> const struct btf_type *t); static void btf_dump_emit_enum_def(struct btf_dump *d, __u32 id, <------><------><------><------> const struct btf_type *t, int lvl); static void btf_dump_emit_fwd_def(struct btf_dump *d, __u32 id, <------><------><------><------> const struct btf_type *t); static void btf_dump_emit_typedef_def(struct btf_dump *d, __u32 id, <------><------><------><------> const struct btf_type *t, int lvl); /* a local view into a shared stack */ struct id_stack { <------>const __u32 *ids; <------>int cnt; }; static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id, <------><------><------><------> const char *fname, int lvl); static void btf_dump_emit_type_chain(struct btf_dump *d, <------><------><------><------> struct id_stack *decl_stack, <------><------><------><------> const char *fname, int lvl); static const char *btf_dump_type_name(struct btf_dump *d, __u32 id); static const char *btf_dump_ident_name(struct btf_dump *d, __u32 id); static size_t btf_dump_name_dups(struct btf_dump *d, struct hashmap *name_map, <------><------><------><------> const char *orig_name); static bool btf_dump_is_blacklisted(struct btf_dump *d, __u32 id) { <------>const struct btf_type *t = btf__type_by_id(d->btf, id); <------>/* __builtin_va_list is a compiler built-in, which causes compilation <------> * errors, when compiling w/ different compiler, then used to compile <------> * original code (e.g., GCC to compile kernel, Clang to use generated <------> * C header from BTF). As it is built-in, it should be already defined <------> * properly internally in compiler. <------> */ <------>if (t->name_off == 0) <------><------>return false; <------>return strcmp(btf_name_of(d, t->name_off), "__builtin_va_list") == 0; } /* * Emit C-syntax definitions of types from chains of BTF types. * * High-level handling of determining necessary forward declarations are handled * by btf_dump_emit_type() itself, but all nitty-gritty details of emitting type * declarations/definitions in C syntax are handled by a combo of * btf_dump_emit_type_decl()/btf_dump_emit_type_chain() w/ delegation to * corresponding btf_dump_emit_*_{def,fwd}() functions. * * We also keep track of "containing struct/union type ID" to determine when * we reference it from inside and thus can avoid emitting unnecessary forward * declaration. * * This algorithm is designed in such a way, that even if some error occurs * (either technical, e.g., out of memory, or logical, i.e., malformed BTF * that doesn't comply to C rules completely), algorithm will try to proceed * and produce as much meaningful output as possible. */ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id) { <------>struct btf_dump_type_aux_state *tstate = &d->type_states[id]; <------>bool top_level_def = cont_id == 0; <------>const struct btf_type *t; <------>__u16 kind; <------>if (tstate->emit_state == EMITTED) <------><------>return; <------>t = btf__type_by_id(d->btf, id); <------>kind = btf_kind(t); <------>if (tstate->emit_state == EMITTING) { <------><------>if (tstate->fwd_emitted) <------><------><------>return; <------><------>switch (kind) { <------><------>case BTF_KIND_STRUCT: <------><------>case BTF_KIND_UNION: <------><------><------>/* <------><------><------> * if we are referencing a struct/union that we are <------><------><------> * part of - then no need for fwd declaration <------><------><------> */ <------><------><------>if (id == cont_id) <------><------><------><------>return; <------><------><------>if (t->name_off == 0) { <------><------><------><------>pr_warn("anonymous struct/union loop, id:[%u]\n", <------><------><------><------><------>id); <------><------><------><------>return; <------><------><------>} <------><------><------>btf_dump_emit_struct_fwd(d, id, t); <------><------><------>btf_dump_printf(d, ";\n\n"); <------><------><------>tstate->fwd_emitted = 1; <------><------><------>break; <------><------>case BTF_KIND_TYPEDEF: <------><------><------>/* <------><------><------> * for typedef fwd_emitted means typedef definition <------><------><------> * was emitted, but it can be used only for "weak" <------><------><------> * references through pointer only, not for embedding <------><------><------> */ <------><------><------>if (!btf_dump_is_blacklisted(d, id)) { <------><------><------><------>btf_dump_emit_typedef_def(d, id, t, 0); <------><------><------><------>btf_dump_printf(d, ";\n\n"); <------><------><------>} <------><------><------>tstate->fwd_emitted = 1; <------><------><------>break; <------><------>default: <------><------><------>break; <------><------>} <------><------>return; <------>} <------>switch (kind) { <------>case BTF_KIND_INT: <------><------>/* Emit type alias definitions if necessary */ <------><------>btf_dump_emit_missing_aliases(d, id, t); <------><------>tstate->emit_state = EMITTED; <------><------>break; <------>case BTF_KIND_ENUM: <------><------>if (top_level_def) { <------><------><------>btf_dump_emit_enum_def(d, id, t, 0); <------><------><------>btf_dump_printf(d, ";\n\n"); <------><------>} <------><------>tstate->emit_state = EMITTED; <------><------>break; <------>case BTF_KIND_PTR: <------>case BTF_KIND_VOLATILE: <------>case BTF_KIND_CONST: <------>case BTF_KIND_RESTRICT: <------><------>btf_dump_emit_type(d, t->type, cont_id); <------><------>break; <------>case BTF_KIND_ARRAY: <------><------>btf_dump_emit_type(d, btf_array(t)->type, cont_id); <------><------>break; <------>case BTF_KIND_FWD: <------><------>btf_dump_emit_fwd_def(d, id, t); <------><------>btf_dump_printf(d, ";\n\n"); <------><------>tstate->emit_state = EMITTED; <------><------>break; <------>case BTF_KIND_TYPEDEF: <------><------>tstate->emit_state = EMITTING; <------><------>btf_dump_emit_type(d, t->type, id); <------><------>/* <------><------> * typedef can server as both definition and forward <------><------> * declaration; at this stage someone depends on <------><------> * typedef as a forward declaration (refers to it <------><------> * through pointer), so unless we already did it, <------><------> * emit typedef as a forward declaration <------><------> */ <------><------>if (!tstate->fwd_emitted && !btf_dump_is_blacklisted(d, id)) { <------><------><------>btf_dump_emit_typedef_def(d, id, t, 0); <------><------><------>btf_dump_printf(d, ";\n\n"); <------><------>} <------><------>tstate->emit_state = EMITTED; <------><------>break; <------>case BTF_KIND_STRUCT: <------>case BTF_KIND_UNION: <------><------>tstate->emit_state = EMITTING; <------><------>/* if it's a top-level struct/union definition or struct/union <------><------> * is anonymous, then in C we'll be emitting all fields and <------><------> * their types (as opposed to just `struct X`), so we need to <------><------> * make sure that all types, referenced from struct/union <------><------> * members have necessary forward-declarations, where <------><------> * applicable <------><------> */ <------><------>if (top_level_def || t->name_off == 0) { <------><------><------>const struct btf_member *m = btf_members(t); <------><------><------>__u16 vlen = btf_vlen(t); <------><------><------>int i, new_cont_id; <------><------><------>new_cont_id = t->name_off == 0 ? cont_id : id; <------><------><------>for (i = 0; i < vlen; i++, m++) <------><------><------><------>btf_dump_emit_type(d, m->type, new_cont_id); <------><------>} else if (!tstate->fwd_emitted && id != cont_id) { <------><------><------>btf_dump_emit_struct_fwd(d, id, t); <------><------><------>btf_dump_printf(d, ";\n\n"); <------><------><------>tstate->fwd_emitted = 1; <------><------>} <------><------>if (top_level_def) { <------><------><------>btf_dump_emit_struct_def(d, id, t, 0); <------><------><------>btf_dump_printf(d, ";\n\n"); <------><------><------>tstate->emit_state = EMITTED; <------><------>} else { <------><------><------>tstate->emit_state = NOT_EMITTED; <------><------>} <------><------>break; <------>case BTF_KIND_FUNC_PROTO: { <------><------>const struct btf_param *p = btf_params(t); <------><------>__u16 vlen = btf_vlen(t); <------><------>int i; <------><------>btf_dump_emit_type(d, t->type, cont_id); <------><------>for (i = 0; i < vlen; i++, p++) <------><------><------>btf_dump_emit_type(d, p->type, cont_id); <------><------>break; <------>} <------>default: <------><------>break; <------>} } static bool btf_is_struct_packed(const struct btf *btf, __u32 id, <------><------><------><------> const struct btf_type *t) { <------>const struct btf_member *m; <------>int align, i, bit_sz; <------>__u16 vlen; <------>align = btf__align_of(btf, id); <------>/* size of a non-packed struct has to be a multiple of its alignment*/ <------>if (align && t->size % align) <------><------>return true; <------>m = btf_members(t); <------>vlen = btf_vlen(t); <------>/* all non-bitfield fields have to be naturally aligned */ <------>for (i = 0; i < vlen; i++, m++) { <------><------>align = btf__align_of(btf, m->type); <------><------>bit_sz = btf_member_bitfield_size(t, i); <------><------>if (align && bit_sz == 0 && m->offset % (8 * align) != 0) <------><------><------>return true; <------>} <------>/* <------> * if original struct was marked as packed, but its layout is <------> * naturally aligned, we'll detect that it's not packed <------> */ <------>return false; } static int chip_away_bits(int total, int at_most) { <------>return total % at_most ? : at_most; } static void btf_dump_emit_bit_padding(const struct btf_dump *d, <------><------><------><------> int cur_off, int m_off, int m_bit_sz, <------><------><------><------> int align, int lvl) { <------>int off_diff = m_off - cur_off; <------>int ptr_bits = d->ptr_sz * 8; <------>if (off_diff <= 0) <------><------>/* no gap */ <------><------>return; <------>if (m_bit_sz == 0 && off_diff < align * 8) <------><------>/* natural padding will take care of a gap */ <------><------>return; <------>while (off_diff > 0) { <------><------>const char *pad_type; <------><------>int pad_bits; <------><------>if (ptr_bits > 32 && off_diff > 32) { <------><------><------>pad_type = "long"; <------><------><------>pad_bits = chip_away_bits(off_diff, ptr_bits); <------><------>} else if (off_diff > 16) { <------><------><------>pad_type = "int"; <------><------><------>pad_bits = chip_away_bits(off_diff, 32); <------><------>} else if (off_diff > 8) { <------><------><------>pad_type = "short"; <------><------><------>pad_bits = chip_away_bits(off_diff, 16); <------><------>} else { <------><------><------>pad_type = "char"; <------><------><------>pad_bits = chip_away_bits(off_diff, 8); <------><------>} <------><------>btf_dump_printf(d, "\n%s%s: %d;", pfx(lvl), pad_type, pad_bits); <------><------>off_diff -= pad_bits; <------>} } static void btf_dump_emit_struct_fwd(struct btf_dump *d, __u32 id, <------><------><------><------> const struct btf_type *t) { <------>btf_dump_printf(d, "%s %s", <------><------><------>btf_is_struct(t) ? "struct" : "union", <------><------><------>btf_dump_type_name(d, id)); } static void btf_dump_emit_struct_def(struct btf_dump *d, <------><------><------><------> __u32 id, <------><------><------><------> const struct btf_type *t, <------><------><------><------> int lvl) { <------>const struct btf_member *m = btf_members(t); <------>bool is_struct = btf_is_struct(t); <------>int align, i, packed, off = 0; <------>__u16 vlen = btf_vlen(t); <------>packed = is_struct ? btf_is_struct_packed(d->btf, id, t) : 0; <------>btf_dump_printf(d, "%s%s%s {", <------><------><------>is_struct ? "struct" : "union", <------><------><------>t->name_off ? " " : "", <------><------><------>btf_dump_type_name(d, id)); <------>for (i = 0; i < vlen; i++, m++) { <------><------>const char *fname; <------><------>int m_off, m_sz; <------><------>fname = btf_name_of(d, m->name_off); <------><------>m_sz = btf_member_bitfield_size(t, i); <------><------>m_off = btf_member_bit_offset(t, i); <------><------>align = packed ? 1 : btf__align_of(d->btf, m->type); <------><------>btf_dump_emit_bit_padding(d, off, m_off, m_sz, align, lvl + 1); <------><------>btf_dump_printf(d, "\n%s", pfx(lvl + 1)); <------><------>btf_dump_emit_type_decl(d, m->type, fname, lvl + 1); <------><------>if (m_sz) { <------><------><------>btf_dump_printf(d, ": %d", m_sz); <------><------><------>off = m_off + m_sz; <------><------>} else { <------><------><------>m_sz = max((__s64)0, btf__resolve_size(d->btf, m->type)); <------><------><------>off = m_off + m_sz * 8; <------><------>} <------><------>btf_dump_printf(d, ";"); <------>} <------>/* pad at the end, if necessary */ <------>if (is_struct) { <------><------>align = packed ? 1 : btf__align_of(d->btf, id); <------><------>btf_dump_emit_bit_padding(d, off, t->size * 8, 0, align, <------><------><------><------><------> lvl + 1); <------>} <------>if (vlen) <------><------>btf_dump_printf(d, "\n"); <------>btf_dump_printf(d, "%s}", pfx(lvl)); <------>if (packed) <------><------>btf_dump_printf(d, " __attribute__((packed))"); } static const char *missing_base_types[][2] = { <------>/* <------> * GCC emits typedefs to its internal __PolyX_t types when compiling Arm <------> * SIMD intrinsics. Alias them to standard base types. <------> */ <------>{ "__Poly8_t", "unsigned char" }, <------>{ "__Poly16_t", "unsigned short" }, <------>{ "__Poly64_t", "unsigned long long" }, <------>{ "__Poly128_t", "unsigned __int128" }, }; static void btf_dump_emit_missing_aliases(struct btf_dump *d, __u32 id, <------><------><------><------><------> const struct btf_type *t) { <------>const char *name = btf_dump_type_name(d, id); <------>int i; <------>for (i = 0; i < ARRAY_SIZE(missing_base_types); i++) { <------><------>if (strcmp(name, missing_base_types[i][0]) == 0) { <------><------><------>btf_dump_printf(d, "typedef %s %s;\n\n", <------><------><------><------><------>missing_base_types[i][1], name); <------><------><------>break; <------><------>} <------>} } static void btf_dump_emit_enum_fwd(struct btf_dump *d, __u32 id, <------><------><------><------> const struct btf_type *t) { <------>btf_dump_printf(d, "enum %s", btf_dump_type_name(d, id)); } static void btf_dump_emit_enum_def(struct btf_dump *d, __u32 id, <------><------><------><------> const struct btf_type *t, <------><------><------><------> int lvl) { <------>const struct btf_enum *v = btf_enum(t); <------>__u16 vlen = btf_vlen(t); <------>const char *name; <------>size_t dup_cnt; <------>int i; <------>btf_dump_printf(d, "enum%s%s", <------><------><------>t->name_off ? " " : "", <------><------><------>btf_dump_type_name(d, id)); <------>if (vlen) { <------><------>btf_dump_printf(d, " {"); <------><------>for (i = 0; i < vlen; i++, v++) { <------><------><------>name = btf_name_of(d, v->name_off); <------><------><------>/* enumerators share namespace with typedef idents */ <------><------><------>dup_cnt = btf_dump_name_dups(d, d->ident_names, name); <------><------><------>if (dup_cnt > 1) { <------><------><------><------>btf_dump_printf(d, "\n%s%s___%zu = %u,", <------><------><------><------><------><------>pfx(lvl + 1), name, dup_cnt, <------><------><------><------><------><------>(__u32)v->val); <------><------><------>} else { <------><------><------><------>btf_dump_printf(d, "\n%s%s = %u,", <------><------><------><------><------><------>pfx(lvl + 1), name, <------><------><------><------><------><------>(__u32)v->val); <------><------><------>} <------><------>} <------><------>btf_dump_printf(d, "\n%s}", pfx(lvl)); <------>} } static void btf_dump_emit_fwd_def(struct btf_dump *d, __u32 id, <------><------><------><------> const struct btf_type *t) { <------>const char *name = btf_dump_type_name(d, id); <------>if (btf_kflag(t)) <------><------>btf_dump_printf(d, "union %s", name); <------>else <------><------>btf_dump_printf(d, "struct %s", name); } static void btf_dump_emit_typedef_def(struct btf_dump *d, __u32 id, <------><------><------><------> const struct btf_type *t, int lvl) { <------>const char *name = btf_dump_ident_name(d, id); <------>/* <------> * Old GCC versions are emitting invalid typedef for __gnuc_va_list <------> * pointing to VOID. This generates warnings from btf_dump() and <------> * results in uncompilable header file, so we are fixing it up here <------> * with valid typedef into __builtin_va_list. <------> */ <------>if (t->type == 0 && strcmp(name, "__gnuc_va_list") == 0) { <------><------>btf_dump_printf(d, "typedef __builtin_va_list __gnuc_va_list"); <------><------>return; <------>} <------>btf_dump_printf(d, "typedef "); <------>btf_dump_emit_type_decl(d, t->type, name, lvl); } static int btf_dump_push_decl_stack_id(struct btf_dump *d, __u32 id) { <------>__u32 *new_stack; <------>size_t new_cap; <------>if (d->decl_stack_cnt >= d->decl_stack_cap) { <------><------>new_cap = max(16, d->decl_stack_cap * 3 / 2); <------><------>new_stack = libbpf_reallocarray(d->decl_stack, new_cap, sizeof(new_stack[0])); <------><------>if (!new_stack) <------><------><------>return -ENOMEM; <------><------>d->decl_stack = new_stack; <------><------>d->decl_stack_cap = new_cap; <------>} <------>d->decl_stack[d->decl_stack_cnt++] = id; <------>return 0; } /* * Emit type declaration (e.g., field type declaration in a struct or argument * declaration in function prototype) in correct C syntax. * * For most types it's trivial, but there are few quirky type declaration * cases worth mentioning: * - function prototypes (especially nesting of function prototypes); * - arrays; * - const/volatile/restrict for pointers vs other types. * * For a good discussion of *PARSING* C syntax (as a human), see * Peter van der Linden's "Expert C Programming: Deep C Secrets", * Ch.3 "Unscrambling Declarations in C". * * It won't help with BTF to C conversion much, though, as it's an opposite * problem. So we came up with this algorithm in reverse to van der Linden's * parsing algorithm. It goes from structured BTF representation of type * declaration to a valid compilable C syntax. * * For instance, consider this C typedef: * typedef const int * const * arr[10] arr_t; * It will be represented in BTF with this chain of BTF types: * [typedef] -> [array] -> [ptr] -> [const] -> [ptr] -> [const] -> [int] * * Notice how [const] modifier always goes before type it modifies in BTF type * graph, but in C syntax, const/volatile/restrict modifiers are written to * the right of pointers, but to the left of other types. There are also other * quirks, like function pointers, arrays of them, functions returning other * functions, etc. * * We handle that by pushing all the types to a stack, until we hit "terminal" * type (int/enum/struct/union/fwd). Then depending on the kind of a type on * top of a stack, modifiers are handled differently. Array/function pointers * have also wildly different syntax and how nesting of them are done. See * code for authoritative definition. * * To avoid allocating new stack for each independent chain of BTF types, we * share one bigger stack, with each chain working only on its own local view * of a stack frame. Some care is required to "pop" stack frames after * processing type declaration chain. */ int btf_dump__emit_type_decl(struct btf_dump *d, __u32 id, <------><------><------> const struct btf_dump_emit_type_decl_opts *opts) { <------>const char *fname; <------>int lvl, err; <------>if (!OPTS_VALID(opts, btf_dump_emit_type_decl_opts)) <------><------>return -EINVAL; <------>err = btf_dump_resize(d); <------>if (err) <------><------>return -EINVAL; <------>fname = OPTS_GET(opts, field_name, ""); <------>lvl = OPTS_GET(opts, indent_level, 0); <------>d->strip_mods = OPTS_GET(opts, strip_mods, false); <------>btf_dump_emit_type_decl(d, id, fname, lvl); <------>d->strip_mods = false; <------>return 0; } static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id, <------><------><------><------> const char *fname, int lvl) { <------>struct id_stack decl_stack; <------>const struct btf_type *t; <------>int err, stack_start; <------>stack_start = d->decl_stack_cnt; <------>for (;;) { <------><------>t = btf__type_by_id(d->btf, id); <------><------>if (d->strip_mods && btf_is_mod(t)) <------><------><------>goto skip_mod; <------><------>err = btf_dump_push_decl_stack_id(d, id); <------><------>if (err < 0) { <------><------><------>/* <------><------><------> * if we don't have enough memory for entire type decl <------><------><------> * chain, restore stack, emit warning, and try to <------><------><------> * proceed nevertheless <------><------><------> */ <------><------><------>pr_warn("not enough memory for decl stack:%d", err); <------><------><------>d->decl_stack_cnt = stack_start; <------><------><------>return; <------><------>} skip_mod: <------><------>/* VOID */ <------><------>if (id == 0) <------><------><------>break; <------><------>switch (btf_kind(t)) { <------><------>case BTF_KIND_PTR: <------><------>case BTF_KIND_VOLATILE: <------><------>case BTF_KIND_CONST: <------><------>case BTF_KIND_RESTRICT: <------><------>case BTF_KIND_FUNC_PROTO: <------><------><------>id = t->type; <------><------><------>break; <------><------>case BTF_KIND_ARRAY: <------><------><------>id = btf_array(t)->type; <------><------><------>break; <------><------>case BTF_KIND_INT: <------><------>case BTF_KIND_ENUM: <------><------>case BTF_KIND_FWD: <------><------>case BTF_KIND_STRUCT: <------><------>case BTF_KIND_UNION: <------><------>case BTF_KIND_TYPEDEF: <------><------><------>goto done; <------><------>default: <------><------><------>pr_warn("unexpected type in decl chain, kind:%u, id:[%u]\n", <------><------><------><------>btf_kind(t), id); <------><------><------>goto done; <------><------>} <------>} done: <------>/* <------> * We might be inside a chain of declarations (e.g., array of function <------> * pointers returning anonymous (so inlined) structs, having another <------> * array field). Each of those needs its own "stack frame" to handle <------> * emitting of declarations. Those stack frames are non-overlapping <------> * portions of shared btf_dump->decl_stack. To make it a bit nicer to <------> * handle this set of nested stacks, we create a view corresponding to <------> * our own "stack frame" and work with it as an independent stack. <------> * We'll need to clean up after emit_type_chain() returns, though. <------> */ <------>decl_stack.ids = d->decl_stack + stack_start; <------>decl_stack.cnt = d->decl_stack_cnt - stack_start; <------>btf_dump_emit_type_chain(d, &decl_stack, fname, lvl); <------>/* <------> * emit_type_chain() guarantees that it will pop its entire decl_stack <------> * frame before returning. But it works with a read-only view into <------> * decl_stack, so it doesn't actually pop anything from the <------> * perspective of shared btf_dump->decl_stack, per se. We need to <------> * reset decl_stack state to how it was before us to avoid it growing <------> * all the time. <------> */ <------>d->decl_stack_cnt = stack_start; } static void btf_dump_emit_mods(struct btf_dump *d, struct id_stack *decl_stack) { <------>const struct btf_type *t; <------>__u32 id; <------>while (decl_stack->cnt) { <------><------>id = decl_stack->ids[decl_stack->cnt - 1]; <------><------>t = btf__type_by_id(d->btf, id); <------><------>switch (btf_kind(t)) { <------><------>case BTF_KIND_VOLATILE: <------><------><------>btf_dump_printf(d, "volatile "); <------><------><------>break; <------><------>case BTF_KIND_CONST: <------><------><------>btf_dump_printf(d, "const "); <------><------><------>break; <------><------>case BTF_KIND_RESTRICT: <------><------><------>btf_dump_printf(d, "restrict "); <------><------><------>break; <------><------>default: <------><------><------>return; <------><------>} <------><------>decl_stack->cnt--; <------>} } static void btf_dump_drop_mods(struct btf_dump *d, struct id_stack *decl_stack) { <------>const struct btf_type *t; <------>__u32 id; <------>while (decl_stack->cnt) { <------><------>id = decl_stack->ids[decl_stack->cnt - 1]; <------><------>t = btf__type_by_id(d->btf, id); <------><------>if (!btf_is_mod(t)) <------><------><------>return; <------><------>decl_stack->cnt--; <------>} } static void btf_dump_emit_name(const struct btf_dump *d, <------><------><------> const char *name, bool last_was_ptr) { <------>bool separate = name[0] && !last_was_ptr; <------>btf_dump_printf(d, "%s%s", separate ? " " : "", name); } static void btf_dump_emit_type_chain(struct btf_dump *d, <------><------><------><------> struct id_stack *decls, <------><------><------><------> const char *fname, int lvl) { <------>/* <------> * last_was_ptr is used to determine if we need to separate pointer <------> * asterisk (*) from previous part of type signature with space, so <------> * that we get `int ***`, instead of `int * * *`. We default to true <------> * for cases where we have single pointer in a chain. E.g., in ptr -> <------> * func_proto case. func_proto will start a new emit_type_chain call <------> * with just ptr, which should be emitted as (*) or (*<fname>), so we <------> * don't want to prepend space for that last pointer. <------> */ <------>bool last_was_ptr = true; <------>const struct btf_type *t; <------>const char *name; <------>__u16 kind; <------>__u32 id; <------>while (decls->cnt) { <------><------>id = decls->ids[--decls->cnt]; <------><------>if (id == 0) { <------><------><------>/* VOID is a special snowflake */ <------><------><------>btf_dump_emit_mods(d, decls); <------><------><------>btf_dump_printf(d, "void"); <------><------><------>last_was_ptr = false; <------><------><------>continue; <------><------>} <------><------>t = btf__type_by_id(d->btf, id); <------><------>kind = btf_kind(t); <------><------>switch (kind) { <------><------>case BTF_KIND_INT: <------><------><------>btf_dump_emit_mods(d, decls); <------><------><------>name = btf_name_of(d, t->name_off); <------><------><------>btf_dump_printf(d, "%s", name); <------><------><------>break; <------><------>case BTF_KIND_STRUCT: <------><------>case BTF_KIND_UNION: <------><------><------>btf_dump_emit_mods(d, decls); <------><------><------>/* inline anonymous struct/union */ <------><------><------>if (t->name_off == 0) <------><------><------><------>btf_dump_emit_struct_def(d, id, t, lvl); <------><------><------>else <------><------><------><------>btf_dump_emit_struct_fwd(d, id, t); <------><------><------>break; <------><------>case BTF_KIND_ENUM: <------><------><------>btf_dump_emit_mods(d, decls); <------><------><------>/* inline anonymous enum */ <------><------><------>if (t->name_off == 0) <------><------><------><------>btf_dump_emit_enum_def(d, id, t, lvl); <------><------><------>else <------><------><------><------>btf_dump_emit_enum_fwd(d, id, t); <------><------><------>break; <------><------>case BTF_KIND_FWD: <------><------><------>btf_dump_emit_mods(d, decls); <------><------><------>btf_dump_emit_fwd_def(d, id, t); <------><------><------>break; <------><------>case BTF_KIND_TYPEDEF: <------><------><------>btf_dump_emit_mods(d, decls); <------><------><------>btf_dump_printf(d, "%s", btf_dump_ident_name(d, id)); <------><------><------>break; <------><------>case BTF_KIND_PTR: <------><------><------>btf_dump_printf(d, "%s", last_was_ptr ? "*" : " *"); <------><------><------>break; <------><------>case BTF_KIND_VOLATILE: <------><------><------>btf_dump_printf(d, " volatile"); <------><------><------>break; <------><------>case BTF_KIND_CONST: <------><------><------>btf_dump_printf(d, " const"); <------><------><------>break; <------><------>case BTF_KIND_RESTRICT: <------><------><------>btf_dump_printf(d, " restrict"); <------><------><------>break; <------><------>case BTF_KIND_ARRAY: { <------><------><------>const struct btf_array *a = btf_array(t); <------><------><------>const struct btf_type *next_t; <------><------><------>__u32 next_id; <------><------><------>bool multidim; <------><------><------>/* <------><------><------> * GCC has a bug <------><------><------> * (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=8354) <------><------><------> * which causes it to emit extra const/volatile <------><------><------> * modifiers for an array, if array's element type has <------><------><------> * const/volatile modifiers. Clang doesn't do that. <------><------><------> * In general, it doesn't seem very meaningful to have <------><------><------> * a const/volatile modifier for array, so we are <------><------><------> * going to silently skip them here. <------><------><------> */ <------><------><------>btf_dump_drop_mods(d, decls); <------><------><------>if (decls->cnt == 0) { <------><------><------><------>btf_dump_emit_name(d, fname, last_was_ptr); <------><------><------><------>btf_dump_printf(d, "[%u]", a->nelems); <------><------><------><------>return; <------><------><------>} <------><------><------>next_id = decls->ids[decls->cnt - 1]; <------><------><------>next_t = btf__type_by_id(d->btf, next_id); <------><------><------>multidim = btf_is_array(next_t); <------><------><------>/* we need space if we have named non-pointer */ <------><------><------>if (fname[0] && !last_was_ptr) <------><------><------><------>btf_dump_printf(d, " "); <------><------><------>/* no parentheses for multi-dimensional array */ <------><------><------>if (!multidim) <------><------><------><------>btf_dump_printf(d, "("); <------><------><------>btf_dump_emit_type_chain(d, decls, fname, lvl); <------><------><------>if (!multidim) <------><------><------><------>btf_dump_printf(d, ")"); <------><------><------>btf_dump_printf(d, "[%u]", a->nelems); <------><------><------>return; <------><------>} <------><------>case BTF_KIND_FUNC_PROTO: { <------><------><------>const struct btf_param *p = btf_params(t); <------><------><------>__u16 vlen = btf_vlen(t); <------><------><------>int i; <------><------><------>/* <------><------><------> * GCC emits extra volatile qualifier for <------><------><------> * __attribute__((noreturn)) function pointers. Clang <------><------><------> * doesn't do it. It's a GCC quirk for backwards <------><------><------> * compatibility with code written for GCC <2.5. So, <------><------><------> * similarly to extra qualifiers for array, just drop <------><------><------> * them, instead of handling them. <------><------><------> */ <------><------><------>btf_dump_drop_mods(d, decls); <------><------><------>if (decls->cnt) { <------><------><------><------>btf_dump_printf(d, " ("); <------><------><------><------>btf_dump_emit_type_chain(d, decls, fname, lvl); <------><------><------><------>btf_dump_printf(d, ")"); <------><------><------>} else { <------><------><------><------>btf_dump_emit_name(d, fname, last_was_ptr); <------><------><------>} <------><------><------>btf_dump_printf(d, "("); <------><------><------>/* <------><------><------> * Clang for BPF target generates func_proto with no <------><------><------> * args as a func_proto with a single void arg (e.g., <------><------><------> * `int (*f)(void)` vs just `int (*f)()`). We are <------><------><------> * going to pretend there are no args for such case. <------><------><------> */ <------><------><------>if (vlen == 1 && p->type == 0) { <------><------><------><------>btf_dump_printf(d, ")"); <------><------><------><------>return; <------><------><------>} <------><------><------>for (i = 0; i < vlen; i++, p++) { <------><------><------><------>if (i > 0) <------><------><------><------><------>btf_dump_printf(d, ", "); <------><------><------><------>/* last arg of type void is vararg */ <------><------><------><------>if (i == vlen - 1 && p->type == 0) { <------><------><------><------><------>btf_dump_printf(d, "..."); <------><------><------><------><------>break; <------><------><------><------>} <------><------><------><------>name = btf_name_of(d, p->name_off); <------><------><------><------>btf_dump_emit_type_decl(d, p->type, name, lvl); <------><------><------>} <------><------><------>btf_dump_printf(d, ")"); <------><------><------>return; <------><------>} <------><------>default: <------><------><------>pr_warn("unexpected type in decl chain, kind:%u, id:[%u]\n", <------><------><------><------>kind, id); <------><------><------>return; <------><------>} <------><------>last_was_ptr = kind == BTF_KIND_PTR; <------>} <------>btf_dump_emit_name(d, fname, last_was_ptr); } /* return number of duplicates (occurrences) of a given name */ static size_t btf_dump_name_dups(struct btf_dump *d, struct hashmap *name_map, <------><------><------><------> const char *orig_name) { <------>size_t dup_cnt = 0; <------>hashmap__find(name_map, orig_name, (void **)&dup_cnt); <------>dup_cnt++; <------>hashmap__set(name_map, orig_name, (void *)dup_cnt, NULL, NULL); <------>return dup_cnt; } static const char *btf_dump_resolve_name(struct btf_dump *d, __u32 id, <------><------><------><------><------> struct hashmap *name_map) { <------>struct btf_dump_type_aux_state *s = &d->type_states[id]; <------>const struct btf_type *t = btf__type_by_id(d->btf, id); <------>const char *orig_name = btf_name_of(d, t->name_off); <------>const char **cached_name = &d->cached_names[id]; <------>size_t dup_cnt; <------>if (t->name_off == 0) <------><------>return ""; <------>if (s->name_resolved) <------><------>return *cached_name ? *cached_name : orig_name; <------>if (btf_is_fwd(t) || (btf_is_enum(t) && btf_vlen(t) == 0)) { <------><------>s->name_resolved = 1; <------><------>return orig_name; <------>} <------>dup_cnt = btf_dump_name_dups(d, name_map, orig_name); <------>if (dup_cnt > 1) { <------><------>const size_t max_len = 256; <------><------>char new_name[max_len]; <------><------>snprintf(new_name, max_len, "%s___%zu", orig_name, dup_cnt); <------><------>*cached_name = strdup(new_name); <------>} <------>s->name_resolved = 1; <------>return *cached_name ? *cached_name : orig_name; } static const char *btf_dump_type_name(struct btf_dump *d, __u32 id) { <------>return btf_dump_resolve_name(d, id, d->type_names); } static const char *btf_dump_ident_name(struct btf_dump *d, __u32 id) { <------>return btf_dump_resolve_name(d, id, d->ident_names); }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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