diff options
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 165 |
1 files changed, 85 insertions, 80 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index a58569b7e4bf..01d45f0c40d0 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3192,86 +3192,6 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) } } - if (!kernel_supports(obj, FEAT_BTF_DECL_TAG)) - goto skip_exception_cb; - for (i = 0; i < obj->nr_programs; i++) { - struct bpf_program *prog = &obj->programs[i]; - int j, k, n; - - if (prog_is_subprog(obj, prog)) - continue; - n = btf__type_cnt(obj->btf); - for (j = 1; j < n; j++) { - const char *str = "exception_callback:", *name; - size_t len = strlen(str); - struct btf_type *t; - - t = btf_type_by_id(obj->btf, j); - if (!btf_is_decl_tag(t) || btf_decl_tag(t)->component_idx != -1) - continue; - - name = btf__str_by_offset(obj->btf, t->name_off); - if (strncmp(name, str, len)) - continue; - - t = btf_type_by_id(obj->btf, t->type); - if (!btf_is_func(t) || btf_func_linkage(t) != BTF_FUNC_GLOBAL) { - pr_warn("prog '%s': exception_callback:<value> decl tag not applied to the main program\n", - prog->name); - return -EINVAL; - } - if (strcmp(prog->name, btf__str_by_offset(obj->btf, t->name_off))) - continue; - /* Multiple callbacks are specified for the same prog, - * the verifier will eventually return an error for this - * case, hence simply skip appending a subprog. - */ - if (prog->exception_cb_idx >= 0) { - prog->exception_cb_idx = -1; - break; - } - - name += len; - if (str_is_empty(name)) { - pr_warn("prog '%s': exception_callback:<value> decl tag contains empty value\n", - prog->name); - return -EINVAL; - } - - for (k = 0; k < obj->nr_programs; k++) { - struct bpf_program *subprog = &obj->programs[k]; - - if (!prog_is_subprog(obj, subprog)) - continue; - if (strcmp(name, subprog->name)) - continue; - /* Enforce non-hidden, as from verifier point of - * view it expects global functions, whereas the - * mark_btf_static fixes up linkage as static. - */ - if (!subprog->sym_global || subprog->mark_btf_static) { - pr_warn("prog '%s': exception callback %s must be a global non-hidden function\n", - prog->name, subprog->name); - return -EINVAL; - } - /* Let's see if we already saw a static exception callback with the same name */ - if (prog->exception_cb_idx >= 0) { - pr_warn("prog '%s': multiple subprogs with same name as exception callback '%s'\n", - prog->name, subprog->name); - return -EINVAL; - } - prog->exception_cb_idx = k; - break; - } - - if (prog->exception_cb_idx >= 0) - continue; - pr_warn("prog '%s': cannot find exception callback '%s'\n", prog->name, name); - return -ENOENT; - } - } -skip_exception_cb: - sanitize = btf_needs_sanitization(obj); if (sanitize) { const void *raw_data; @@ -6661,6 +6581,88 @@ static void bpf_object__sort_relos(struct bpf_object *obj) } } +static int bpf_prog_assign_exc_cb(struct bpf_object *obj, struct bpf_program *prog) +{ + const char *str = "exception_callback:"; + size_t pfx_len = strlen(str); + int i, j, n; + + if (!obj->btf || !kernel_supports(obj, FEAT_BTF_DECL_TAG)) + return 0; + + n = btf__type_cnt(obj->btf); + for (i = 1; i < n; i++) { + const char *name; + struct btf_type *t; + + t = btf_type_by_id(obj->btf, i); + if (!btf_is_decl_tag(t) || btf_decl_tag(t)->component_idx != -1) + continue; + + name = btf__str_by_offset(obj->btf, t->name_off); + if (strncmp(name, str, pfx_len) != 0) + continue; + + t = btf_type_by_id(obj->btf, t->type); + if (!btf_is_func(t) || btf_func_linkage(t) != BTF_FUNC_GLOBAL) { + pr_warn("prog '%s': exception_callback:<value> decl tag not applied to the main program\n", + prog->name); + return -EINVAL; + } + if (strcmp(prog->name, btf__str_by_offset(obj->btf, t->name_off)) != 0) + continue; + /* Multiple callbacks are specified for the same prog, + * the verifier will eventually return an error for this + * case, hence simply skip appending a subprog. + */ + if (prog->exception_cb_idx >= 0) { + prog->exception_cb_idx = -1; + break; + } + + name += pfx_len; + if (str_is_empty(name)) { + pr_warn("prog '%s': exception_callback:<value> decl tag contains empty value\n", + prog->name); + return -EINVAL; + } + + for (j = 0; j < obj->nr_programs; j++) { + struct bpf_program *subprog = &obj->programs[j]; + + if (!prog_is_subprog(obj, subprog)) + continue; + if (strcmp(name, subprog->name) != 0) + continue; + /* Enforce non-hidden, as from verifier point of + * view it expects global functions, whereas the + * mark_btf_static fixes up linkage as static. + */ + if (!subprog->sym_global || subprog->mark_btf_static) { + pr_warn("prog '%s': exception callback %s must be a global non-hidden function\n", + prog->name, subprog->name); + return -EINVAL; + } + /* Let's see if we already saw a static exception callback with the same name */ + if (prog->exception_cb_idx >= 0) { + pr_warn("prog '%s': multiple subprogs with same name as exception callback '%s'\n", + prog->name, subprog->name); + return -EINVAL; + } + prog->exception_cb_idx = j; + break; + } + + if (prog->exception_cb_idx >= 0) + continue; + + pr_warn("prog '%s': cannot find exception callback '%s'\n", prog->name, name); + return -ENOENT; + } + + return 0; +} + static int bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) { @@ -6721,6 +6723,9 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) return err; } + err = bpf_prog_assign_exc_cb(obj, prog); + if (err) + return err; /* Now, also append exception callback if it has not been done already. */ if (prog->exception_cb_idx >= 0) { struct bpf_program *subprog = &obj->programs[prog->exception_cb_idx]; |