diff options
Diffstat (limited to 'tools/bpf/bpftool/gen.c')
| -rw-r--r-- | tools/bpf/bpftool/gen.c | 421 |
1 files changed, 390 insertions, 31 deletions
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c index 31ade77f5ef8..1d71ff8c52fa 100644 --- a/tools/bpf/bpftool/gen.c +++ b/tools/bpf/bpftool/gen.c @@ -18,6 +18,7 @@ #include <sys/stat.h> #include <sys/mman.h> #include <bpf/btf.h> +#include <bpf/bpf_gen_internal.h> #include "json_writer.h" #include "main.h" @@ -106,8 +107,10 @@ static int codegen_datasec_def(struct bpf_object *obj, if (strcmp(sec_name, ".data") == 0) { sec_ident = "data"; + strip_mods = true; } else if (strcmp(sec_name, ".bss") == 0) { sec_ident = "bss"; + strip_mods = true; } else if (strcmp(sec_name, ".rodata") == 0) { sec_ident = "rodata"; strip_mods = true; @@ -129,6 +132,10 @@ static int codegen_datasec_def(struct bpf_object *obj, int need_off = sec_var->offset, align_off, align; __u32 var_type_id = var->type; + /* static variables are not exposed through BPF skeleton */ + if (btf_var(var)->linkage == BTF_VAR_STATIC) + continue; + if (off > need_off) { p_err("Something is wrong for %s's variable #%d: need offset %d, already at %d.\n", sec_name, i, need_off, off); @@ -268,6 +275,327 @@ static void codegen(const char *template, ...) free(s); } +static void print_hex(const char *data, int data_sz) +{ + int i, len; + + for (i = 0, len = 0; i < data_sz; i++) { + int w = data[i] ? 4 : 2; + + len += w; + if (len > 78) { + printf("\\\n"); + len = w; + } + if (!data[i]) + printf("\\0"); + else + printf("\\x%02x", (unsigned char)data[i]); + } +} + +static size_t bpf_map_mmap_sz(const struct bpf_map *map) +{ + long page_sz = sysconf(_SC_PAGE_SIZE); + size_t map_sz; + + map_sz = (size_t)roundup(bpf_map__value_size(map), 8) * bpf_map__max_entries(map); + map_sz = roundup(map_sz, page_sz); + return map_sz; +} + +static void codegen_attach_detach(struct bpf_object *obj, const char *obj_name) +{ + struct bpf_program *prog; + + bpf_object__for_each_program(prog, obj) { + const char *tp_name; + + codegen("\ + \n\ + \n\ + static inline int \n\ + %1$s__%2$s__attach(struct %1$s *skel) \n\ + { \n\ + int prog_fd = skel->progs.%2$s.prog_fd; \n\ + ", obj_name, bpf_program__name(prog)); + + switch (bpf_program__get_type(prog)) { + case BPF_PROG_TYPE_RAW_TRACEPOINT: + tp_name = strchr(bpf_program__section_name(prog), '/') + 1; + printf("\tint fd = bpf_raw_tracepoint_open(\"%s\", prog_fd);\n", tp_name); + break; + case BPF_PROG_TYPE_TRACING: + printf("\tint fd = bpf_raw_tracepoint_open(NULL, prog_fd);\n"); + break; + default: + printf("\tint fd = ((void)prog_fd, 0); /* auto-attach not supported */\n"); + break; + } + codegen("\ + \n\ + \n\ + if (fd > 0) \n\ + skel->links.%1$s_fd = fd; \n\ + return fd; \n\ + } \n\ + ", bpf_program__name(prog)); + } + + codegen("\ + \n\ + \n\ + static inline int \n\ + %1$s__attach(struct %1$s *skel) \n\ + { \n\ + int ret = 0; \n\ + \n\ + ", obj_name); + + bpf_object__for_each_program(prog, obj) { + codegen("\ + \n\ + ret = ret < 0 ? ret : %1$s__%2$s__attach(skel); \n\ + ", obj_name, bpf_program__name(prog)); + } + + codegen("\ + \n\ + return ret < 0 ? ret : 0; \n\ + } \n\ + \n\ + static inline void \n\ + %1$s__detach(struct %1$s *skel) \n\ + { \n\ + ", obj_name); + + bpf_object__for_each_program(prog, obj) { + codegen("\ + \n\ + skel_closenz(skel->links.%1$s_fd); \n\ + ", bpf_program__name(prog)); + } + + codegen("\ + \n\ + } \n\ + "); +} + +static void codegen_destroy(struct bpf_object *obj, const char *obj_name) +{ + struct bpf_program *prog; + struct bpf_map *map; + + codegen("\ + \n\ + static void \n\ + %1$s__destroy(struct %1$s *skel) \n\ + { \n\ + if (!skel) \n\ + return; \n\ + %1$s__detach(skel); \n\ + ", + obj_name); + + bpf_object__for_each_program(prog, obj) { + codegen("\ + \n\ + skel_closenz(skel->progs.%1$s.prog_fd); \n\ + ", bpf_program__name(prog)); + } + + bpf_object__for_each_map(map, obj) { + const char * ident; + + ident = get_map_ident(map); + if (!ident) + continue; + if (bpf_map__is_internal(map) && + (bpf_map__def(map)->map_flags & BPF_F_MMAPABLE)) + printf("\tmunmap(skel->%1$s, %2$zd);\n", + ident, bpf_map_mmap_sz(map)); + codegen("\ + \n\ + skel_closenz(skel->maps.%1$s.map_fd); \n\ + ", ident); + } + codegen("\ + \n\ + free(skel); \n\ + } \n\ + ", + obj_name); +} + +static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *header_guard) +{ + struct bpf_object_load_attr load_attr = {}; + DECLARE_LIBBPF_OPTS(gen_loader_opts, opts); + struct bpf_map *map; + int err = 0; + + err = bpf_object__gen_loader(obj, &opts); + if (err) + return err; + + load_attr.obj = obj; + if (verifier_logs) + /* log_level1 + log_level2 + stats, but not stable UAPI */ + load_attr.log_level = 1 + 2 + 4; + + err = bpf_object__load_xattr(&load_attr); + if (err) { + p_err("failed to load object file"); + goto out; + } + /* If there was no error during load then gen_loader_opts + * are populated with the loader program. + */ + + /* finish generating 'struct skel' */ + codegen("\ + \n\ + }; \n\ + ", obj_name); + + + codegen_attach_detach(obj, obj_name); + + codegen_destroy(obj, obj_name); + + codegen("\ + \n\ + static inline struct %1$s * \n\ + %1$s__open(void) \n\ + { \n\ + struct %1$s *skel; \n\ + \n\ + skel = calloc(sizeof(*skel), 1); \n\ + if (!skel) \n\ + goto cleanup; \n\ + skel->ctx.sz = (void *)&skel->links - (void *)skel; \n\ + ", + obj_name, opts.data_sz); + bpf_object__for_each_map(map, obj) { + const char *ident; + const void *mmap_data = NULL; + size_t mmap_size = 0; + + ident = get_map_ident(map); + if (!ident) + continue; + + if (!bpf_map__is_internal(map) || + !(bpf_map__def(map)->map_flags & BPF_F_MMAPABLE)) + continue; + + codegen("\ + \n\ + skel->%1$s = \n\ + mmap(NULL, %2$zd, PROT_READ | PROT_WRITE,\n\ + MAP_SHARED | MAP_ANONYMOUS, -1, 0); \n\ + if (skel->%1$s == (void *) -1) \n\ + goto cleanup; \n\ + memcpy(skel->%1$s, (void *)\"\\ \n\ + ", ident, bpf_map_mmap_sz(map)); + mmap_data = bpf_map__initial_value(map, &mmap_size); + print_hex(mmap_data, mmap_size); + printf("\", %2$zd);\n" + "\tskel->maps.%1$s.initial_value = (__u64)(long)skel->%1$s;\n", + ident, mmap_size); + } + codegen("\ + \n\ + return skel; \n\ + cleanup: \n\ + %1$s__destroy(skel); \n\ + return NULL; \n\ + } \n\ + \n\ + static inline int \n\ + %1$s__load(struct %1$s *skel) \n\ + { \n\ + struct bpf_load_and_run_opts opts = {}; \n\ + int err; \n\ + \n\ + opts.ctx = (struct bpf_loader_ctx *)skel; \n\ + opts.data_sz = %2$d; \n\ + opts.data = (void *)\"\\ \n\ + ", + obj_name, opts.data_sz); + print_hex(opts.data, opts.data_sz); + codegen("\ + \n\ + \"; \n\ + "); + + codegen("\ + \n\ + opts.insns_sz = %d; \n\ + opts.insns = (void *)\"\\ \n\ + ", + opts.insns_sz); + print_hex(opts.insns, opts.insns_sz); + codegen("\ + \n\ + \"; \n\ + err = bpf_load_and_run(&opts); \n\ + if (err < 0) \n\ + return err; \n\ + ", obj_name); + bpf_object__for_each_map(map, obj) { + const char *ident, *mmap_flags; + + ident = get_map_ident(map); + if (!ident) + continue; + + if (!bpf_map__is_internal(map) || + !(bpf_map__def(map)->map_flags & BPF_F_MMAPABLE)) + continue; + if (bpf_map__def(map)->map_flags & BPF_F_RDONLY_PROG) + mmap_flags = "PROT_READ"; + else + mmap_flags = "PROT_READ | PROT_WRITE"; + + printf("\tskel->%1$s =\n" + "\t\tmmap(skel->%1$s, %2$zd, %3$s, MAP_SHARED | MAP_FIXED,\n" + "\t\t\tskel->maps.%1$s.map_fd, 0);\n", + ident, bpf_map_mmap_sz(map), mmap_flags); + } + codegen("\ + \n\ + return 0; \n\ + } \n\ + \n\ + static inline struct %1$s * \n\ + %1$s__open_and_load(void) \n\ + { \n\ + struct %1$s *skel; \n\ + \n\ + skel = %1$s__open(); \n\ + if (!skel) \n\ + return NULL; \n\ + if (%1$s__load(skel)) { \n\ + %1$s__destroy(skel); \n\ + return NULL; \n\ + } \n\ + return skel; \n\ + } \n\ + ", obj_name); + + codegen("\ + \n\ + \n\ + #endif /* %s */ \n\ + ", + header_guard); + err = 0; +out: + return err; +} + static int do_skeleton(int argc, char **argv) { char header_guard[MAX_OBJ_NAME_LEN + sizeof("__SKEL_H__")]; @@ -277,7 +605,7 @@ static int do_skeleton(int argc, char **argv) struct bpf_object *obj = NULL; const char *file, *ident; struct bpf_program *prog; - int fd, len, err = -1; + int fd, err = -1; struct bpf_map *map; struct btf *btf; struct stat st; @@ -359,7 +687,25 @@ static int do_skeleton(int argc, char **argv) } get_header_guard(header_guard, obj_name); - codegen("\ + if (use_loader) { + codegen("\ + \n\ + /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ \n\ + /* THIS FILE IS AUTOGENERATED! */ \n\ + #ifndef %2$s \n\ + #define %2$s \n\ + \n\ + #include <stdlib.h> \n\ + #include <bpf/bpf.h> \n\ + #include <bpf/skel_internal.h> \n\ + \n\ + struct %1$s { \n\ + struct bpf_loader_ctx ctx; \n\ + ", + obj_name, header_guard + ); + } else { + codegen("\ \n\ /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ \n\ \n\ @@ -367,6 +713,7 @@ static int do_skeleton(int argc, char **argv) #ifndef %2$s \n\ #define %2$s \n\ \n\ + #include <errno.h> \n\ #include <stdlib.h> \n\ #include <bpf/libbpf.h> \n\ \n\ @@ -375,7 +722,8 @@ static int do_skeleton(int argc, char **argv) struct bpf_object *obj; \n\ ", obj_name, header_guard - ); + ); + } if (map_cnt) { printf("\tstruct {\n"); @@ -383,7 +731,10 @@ static int do_skeleton(int argc, char **argv) ident = get_map_ident(map); if (!ident) continue; - printf("\t\tstruct bpf_map *%s;\n", ident); + if (use_loader) + printf("\t\tstruct bpf_map_desc %s;\n", ident); + else + printf("\t\tstruct bpf_map *%s;\n", ident); } printf("\t} maps;\n"); } @@ -391,14 +742,22 @@ static int do_skeleton(int argc, char **argv) if (prog_cnt) { printf("\tstruct {\n"); bpf_object__for_each_program(prog, obj) { - printf("\t\tstruct bpf_program *%s;\n", - bpf_program__name(prog)); + if (use_loader) + printf("\t\tstruct bpf_prog_desc %s;\n", + bpf_program__name(prog)); + else + printf("\t\tstruct bpf_program *%s;\n", + bpf_program__name(prog)); } printf("\t} progs;\n"); printf("\tstruct {\n"); bpf_object__for_each_program(prog, obj) { - printf("\t\tstruct bpf_link *%s;\n", - bpf_program__name(prog)); + if (use_loader) + printf("\t\tint %s_fd;\n", + bpf_program__name(prog)); + else + printf("\t\tstruct bpf_link *%s;\n", + bpf_program__name(prog)); } printf("\t} links;\n"); } @@ -409,6 +768,10 @@ static int do_skeleton(int argc, char **argv) if (err) goto out; } + if (use_loader) { + err = gen_trace(obj, obj_name, header_guard); + goto out; + } codegen("\ \n\ @@ -431,18 +794,23 @@ static int do_skeleton(int argc, char **argv) %1$s__open_opts(const struct bpf_object_open_opts *opts) \n\ { \n\ struct %1$s *obj; \n\ + int err; \n\ \n\ obj = (struct %1$s *)calloc(1, sizeof(*obj)); \n\ - if (!obj) \n\ + if (!obj) { \n\ + errno = ENOMEM; \n\ return NULL; \n\ - if (%1$s__create_skeleton(obj)) \n\ - goto err; \n\ - if (bpf_object__open_skeleton(obj->skeleton, opts)) \n\ - goto err; \n\ + } \n\ + \n\ + err = %1$s__create_skeleton(obj); \n\ + err = err ?: bpf_object__open_skeleton(obj->skeleton, opts);\n\ + if (err) \n\ + goto err_out; \n\ \n\ return obj; \n\ - err: \n\ + err_out: \n\ %1$s__destroy(obj); \n\ + errno = -err; \n\ return NULL; \n\ } \n\ \n\ @@ -462,12 +830,15 @@ static int do_skeleton(int argc, char **argv) %1$s__open_and_load(void) \n\ { \n\ struct %1$s *obj; \n\ + int err; \n\ \n\ obj = %1$s__open(); \n\ if (!obj) \n\ return NULL; \n\ - if (%1$s__load(obj)) { \n\ + err = %1$s__load(obj); \n\ + if (err) { \n\ %1$s__destroy(obj); \n\ + errno = -err; \n\ return NULL; \n\ } \n\ return obj; \n\ @@ -498,7 +869,7 @@ static int do_skeleton(int argc, char **argv) \n\ s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));\n\ if (!s) \n\ - return -1; \n\ + goto err; \n\ obj->skeleton = s; \n\ \n\ s->sz = sizeof(*s); \n\ @@ -578,19 +949,7 @@ static int do_skeleton(int argc, char **argv) file_sz); /* embed contents of BPF object file */ - for (i = 0, len = 0; i < file_sz; i++) { - int w = obj_data[i] ? 4 : 2; - - len += w; - if (len > 78) { - printf("\\\n"); - len = w; - } - if (!obj_data[i]) - printf("\\0"); - else - printf("\\x%02x", (unsigned char)obj_data[i]); - } + print_hex(obj_data, file_sz); codegen("\ \n\ @@ -599,7 +958,7 @@ static int do_skeleton(int argc, char **argv) return 0; \n\ err: \n\ bpf_object__destroy_skeleton(s); \n\ - return -1; \n\ + return -ENOMEM; \n\ } \n\ \n\ #endif /* %s */ \n\ @@ -636,7 +995,7 @@ static int do_object(int argc, char **argv) while (argc) { file = GET_ARG(); - err = bpf_linker__add_file(linker, file); + err = bpf_linker__add_file(linker, file, NULL); if (err) { p_err("failed to link '%s': %s (%d)", file, strerror(err), err); goto out; |