diff options
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 198 |
1 files changed, 168 insertions, 30 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 96ff1aa4bf6a..a295f6acf98f 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -82,17 +82,22 @@ static const char * const attach_type_name[] = { [BPF_CGROUP_INET6_BIND] = "cgroup_inet6_bind", [BPF_CGROUP_INET4_CONNECT] = "cgroup_inet4_connect", [BPF_CGROUP_INET6_CONNECT] = "cgroup_inet6_connect", + [BPF_CGROUP_UNIX_CONNECT] = "cgroup_unix_connect", [BPF_CGROUP_INET4_POST_BIND] = "cgroup_inet4_post_bind", [BPF_CGROUP_INET6_POST_BIND] = "cgroup_inet6_post_bind", [BPF_CGROUP_INET4_GETPEERNAME] = "cgroup_inet4_getpeername", [BPF_CGROUP_INET6_GETPEERNAME] = "cgroup_inet6_getpeername", + [BPF_CGROUP_UNIX_GETPEERNAME] = "cgroup_unix_getpeername", [BPF_CGROUP_INET4_GETSOCKNAME] = "cgroup_inet4_getsockname", [BPF_CGROUP_INET6_GETSOCKNAME] = "cgroup_inet6_getsockname", + [BPF_CGROUP_UNIX_GETSOCKNAME] = "cgroup_unix_getsockname", [BPF_CGROUP_UDP4_SENDMSG] = "cgroup_udp4_sendmsg", [BPF_CGROUP_UDP6_SENDMSG] = "cgroup_udp6_sendmsg", + [BPF_CGROUP_UNIX_SENDMSG] = "cgroup_unix_sendmsg", [BPF_CGROUP_SYSCTL] = "cgroup_sysctl", [BPF_CGROUP_UDP4_RECVMSG] = "cgroup_udp4_recvmsg", [BPF_CGROUP_UDP6_RECVMSG] = "cgroup_udp6_recvmsg", + [BPF_CGROUP_UNIX_RECVMSG] = "cgroup_unix_recvmsg", [BPF_CGROUP_GETSOCKOPT] = "cgroup_getsockopt", [BPF_CGROUP_SETSOCKOPT] = "cgroup_setsockopt", [BPF_SK_SKB_STREAM_PARSER] = "sk_skb_stream_parser", @@ -436,9 +441,11 @@ struct bpf_program { int fd; bool autoload; bool autoattach; + bool sym_global; bool mark_btf_static; enum bpf_prog_type type; enum bpf_attach_type expected_attach_type; + int exception_cb_idx; int prog_ifindex; __u32 attach_btf_obj_fd; @@ -765,6 +772,7 @@ bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog, prog->type = BPF_PROG_TYPE_UNSPEC; prog->fd = -1; + prog->exception_cb_idx = -1; /* libbpf's convention for SEC("?abc...") is that it's just like * SEC("abc...") but the corresponding bpf_program starts out with @@ -871,14 +879,16 @@ bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data, if (err) return err; + if (ELF64_ST_BIND(sym->st_info) != STB_LOCAL) + prog->sym_global = true; + /* if function is a global/weak symbol, but has restricted * (STV_HIDDEN or STV_INTERNAL) visibility, mark its BTF FUNC * as static to enable more permissive BPF verification mode * with more outside context available to BPF verifier */ - if (ELF64_ST_BIND(sym->st_info) != STB_LOCAL - && (ELF64_ST_VISIBILITY(sym->st_other) == STV_HIDDEN - || ELF64_ST_VISIBILITY(sym->st_other) == STV_INTERNAL)) + if (prog->sym_global && (ELF64_ST_VISIBILITY(sym->st_other) == STV_HIDDEN + || ELF64_ST_VISIBILITY(sym->st_other) == STV_INTERNAL)) prog->mark_btf_static = true; nr_progs++; @@ -3142,6 +3152,86 @@ 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; @@ -6235,13 +6325,45 @@ static int append_subprog_relos(struct bpf_program *main_prog, struct bpf_progra } static int +bpf_object__append_subprog_code(struct bpf_object *obj, struct bpf_program *main_prog, + struct bpf_program *subprog) +{ + struct bpf_insn *insns; + size_t new_cnt; + int err; + + subprog->sub_insn_off = main_prog->insns_cnt; + + new_cnt = main_prog->insns_cnt + subprog->insns_cnt; + insns = libbpf_reallocarray(main_prog->insns, new_cnt, sizeof(*insns)); + if (!insns) { + pr_warn("prog '%s': failed to realloc prog code\n", main_prog->name); + return -ENOMEM; + } + main_prog->insns = insns; + main_prog->insns_cnt = new_cnt; + + memcpy(main_prog->insns + subprog->sub_insn_off, subprog->insns, + subprog->insns_cnt * sizeof(*insns)); + + pr_debug("prog '%s': added %zu insns from sub-prog '%s'\n", + main_prog->name, subprog->insns_cnt, subprog->name); + + /* The subprog insns are now appended. Append its relos too. */ + err = append_subprog_relos(main_prog, subprog); + if (err) + return err; + return 0; +} + +static int bpf_object__reloc_code(struct bpf_object *obj, struct bpf_program *main_prog, struct bpf_program *prog) { - size_t sub_insn_idx, insn_idx, new_cnt; + size_t sub_insn_idx, insn_idx; struct bpf_program *subprog; - struct bpf_insn *insns, *insn; struct reloc_desc *relo; + struct bpf_insn *insn; int err; err = reloc_prog_func_and_line_info(obj, main_prog, prog); @@ -6316,25 +6438,7 @@ bpf_object__reloc_code(struct bpf_object *obj, struct bpf_program *main_prog, * and relocate. */ if (subprog->sub_insn_off == 0) { - subprog->sub_insn_off = main_prog->insns_cnt; - - new_cnt = main_prog->insns_cnt + subprog->insns_cnt; - insns = libbpf_reallocarray(main_prog->insns, new_cnt, sizeof(*insns)); - if (!insns) { - pr_warn("prog '%s': failed to realloc prog code\n", main_prog->name); - return -ENOMEM; - } - main_prog->insns = insns; - main_prog->insns_cnt = new_cnt; - - memcpy(main_prog->insns + subprog->sub_insn_off, subprog->insns, - subprog->insns_cnt * sizeof(*insns)); - - pr_debug("prog '%s': added %zu insns from sub-prog '%s'\n", - main_prog->name, subprog->insns_cnt, subprog->name); - - /* The subprog insns are now appended. Append its relos too. */ - err = append_subprog_relos(main_prog, subprog); + err = bpf_object__append_subprog_code(obj, main_prog, subprog); if (err) return err; err = bpf_object__reloc_code(obj, main_prog, subprog); @@ -6568,6 +6672,25 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) prog->name, 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]; + + /* Calling exception callback directly is disallowed, which the + * verifier will reject later. In case it was processed already, + * we can skip this step, otherwise for all other valid cases we + * have to append exception callback now. + */ + if (subprog->sub_insn_off == 0) { + err = bpf_object__append_subprog_code(obj, prog, subprog); + if (err) + return err; + err = bpf_object__reloc_code(obj, prog, subprog); + if (err) + return err; + } + } } /* Process data relos for main programs */ for (i = 0; i < obj->nr_programs; i++) { @@ -8842,14 +8965,19 @@ static const struct bpf_sec_def section_defs[] = { SEC_DEF("cgroup/bind6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_BIND, SEC_ATTACHABLE), SEC_DEF("cgroup/connect4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_CONNECT, SEC_ATTACHABLE), SEC_DEF("cgroup/connect6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_CONNECT, SEC_ATTACHABLE), + SEC_DEF("cgroup/connect_unix", CGROUP_SOCK_ADDR, BPF_CGROUP_UNIX_CONNECT, SEC_ATTACHABLE), SEC_DEF("cgroup/sendmsg4", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_SENDMSG, SEC_ATTACHABLE), SEC_DEF("cgroup/sendmsg6", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_SENDMSG, SEC_ATTACHABLE), + SEC_DEF("cgroup/sendmsg_unix", CGROUP_SOCK_ADDR, BPF_CGROUP_UNIX_SENDMSG, SEC_ATTACHABLE), SEC_DEF("cgroup/recvmsg4", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_RECVMSG, SEC_ATTACHABLE), SEC_DEF("cgroup/recvmsg6", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_RECVMSG, SEC_ATTACHABLE), + SEC_DEF("cgroup/recvmsg_unix", CGROUP_SOCK_ADDR, BPF_CGROUP_UNIX_RECVMSG, SEC_ATTACHABLE), SEC_DEF("cgroup/getpeername4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETPEERNAME, SEC_ATTACHABLE), SEC_DEF("cgroup/getpeername6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETPEERNAME, SEC_ATTACHABLE), + SEC_DEF("cgroup/getpeername_unix", CGROUP_SOCK_ADDR, BPF_CGROUP_UNIX_GETPEERNAME, SEC_ATTACHABLE), SEC_DEF("cgroup/getsockname4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETSOCKNAME, SEC_ATTACHABLE), SEC_DEF("cgroup/getsockname6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETSOCKNAME, SEC_ATTACHABLE), + SEC_DEF("cgroup/getsockname_unix", CGROUP_SOCK_ADDR, BPF_CGROUP_UNIX_GETSOCKNAME, SEC_ATTACHABLE), SEC_DEF("cgroup/sysctl", CGROUP_SYSCTL, BPF_CGROUP_SYSCTL, SEC_ATTACHABLE), SEC_DEF("cgroup/getsockopt", CGROUP_SOCKOPT, BPF_CGROUP_GETSOCKOPT, SEC_ATTACHABLE), SEC_DEF("cgroup/setsockopt", CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT, SEC_ATTACHABLE), @@ -10996,7 +11124,7 @@ static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, stru *link = NULL; - n = sscanf(prog->sec_name, "%m[^/]/%m[^:]:%ms", + n = sscanf(prog->sec_name, "%m[^/]/%m[^:]:%m[^\n]", &probe_type, &binary_path, &func_name); switch (n) { case 1: @@ -11506,14 +11634,14 @@ err_out: static int attach_uprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link) { DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts); - char *probe_type = NULL, *binary_path = NULL, *func_name = NULL; - int n, ret = -EINVAL; + char *probe_type = NULL, *binary_path = NULL, *func_name = NULL, *func_off; + int n, c, ret = -EINVAL; long offset = 0; *link = NULL; - n = sscanf(prog->sec_name, "%m[^/]/%m[^:]:%m[a-zA-Z0-9_.]+%li", - &probe_type, &binary_path, &func_name, &offset); + n = sscanf(prog->sec_name, "%m[^/]/%m[^:]:%m[^\n]", + &probe_type, &binary_path, &func_name); switch (n) { case 1: /* handle SEC("u[ret]probe") - format is valid, but auto-attach is impossible. */ @@ -11524,7 +11652,17 @@ static int attach_uprobe(const struct bpf_program *prog, long cookie, struct bpf prog->name, prog->sec_name); break; case 3: - case 4: + /* check if user specifies `+offset`, if yes, this should be + * the last part of the string, make sure sscanf read to EOL + */ + func_off = strrchr(func_name, '+'); + if (func_off) { + n = sscanf(func_off, "+%li%n", &offset, &c); + if (n == 1 && *(func_off + c) == '\0') + func_off[0] = '\0'; + else + offset = 0; + } opts.retprobe = strcmp(probe_type, "uretprobe") == 0 || strcmp(probe_type, "uretprobe.s") == 0; if (opts.retprobe && offset != 0) { |