diff options
Diffstat (limited to 'tools')
52 files changed, 3757 insertions, 92 deletions
diff --git a/tools/bpf/bpftool/feature.c b/tools/bpf/bpftool/feature.c index 290998c82de1..f041c4a6a1f2 100644 --- a/tools/bpf/bpftool/feature.c +++ b/tools/bpf/bpftool/feature.c @@ -567,7 +567,7 @@ probe_prog_type(enum bpf_prog_type prog_type, bool *supported_types, res = probe_prog_type_ifindex(prog_type, ifindex); } else { - res = libbpf_probe_bpf_prog_type(prog_type, NULL); + res = libbpf_probe_bpf_prog_type(prog_type, NULL) > 0; } #ifdef USE_LIBCAP diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c index 97dec81950e5..8fb0116f9136 100644 --- a/tools/bpf/bpftool/link.c +++ b/tools/bpf/bpftool/link.c @@ -20,6 +20,9 @@ static const char * const link_type_name[] = { [BPF_LINK_TYPE_CGROUP] = "cgroup", [BPF_LINK_TYPE_ITER] = "iter", [BPF_LINK_TYPE_NETNS] = "netns", + [BPF_LINK_TYPE_XDP] = "xdp", + [BPF_LINK_TYPE_PERF_EVENT] = "perf_event", + [BPF_LINK_TYPE_KPROBE_MULTI] = "kprobe_multi", }; static struct hashmap *link_table; diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index bc4e05542c2b..8643b37d4e43 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -68,6 +68,7 @@ const char * const prog_type_name[] = { [BPF_PROG_TYPE_EXT] = "ext", [BPF_PROG_TYPE_LSM] = "lsm", [BPF_PROG_TYPE_SK_LOOKUP] = "sk_lookup", + [BPF_PROG_TYPE_SYSCALL] = "syscall", }; const size_t prog_type_name_size = ARRAY_SIZE(prog_type_name); diff --git a/tools/include/uapi/linux/btf.h b/tools/include/uapi/linux/btf.h index b0d8fea1951d..a9162a6c0284 100644 --- a/tools/include/uapi/linux/btf.h +++ b/tools/include/uapi/linux/btf.h @@ -33,8 +33,8 @@ struct btf_type { /* "info" bits arrangement * bits 0-15: vlen (e.g. # of struct's members) * bits 16-23: unused - * bits 24-27: kind (e.g. int, ptr, array...etc) - * bits 28-30: unused + * bits 24-28: kind (e.g. int, ptr, array...etc) + * bits 29-30: unused * bit 31: kind_flag, currently used by * struct, union and fwd */ diff --git a/tools/lib/bpf/Build b/tools/lib/bpf/Build index 94f0a146bb7b..31a1a9015902 100644 --- a/tools/lib/bpf/Build +++ b/tools/lib/bpf/Build @@ -1,3 +1,4 @@ libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o str_error.o \ netlink.o bpf_prog_linfo.o libbpf_probes.o xsk.o hashmap.o \ - btf_dump.o ringbuf.o strset.o linker.o gen_loader.o relo_core.o + btf_dump.o ringbuf.o strset.o linker.o gen_loader.o relo_core.o \ + usdt.o diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index 064c89e31560..64741c55b8e3 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -239,7 +239,7 @@ install_lib: all_cmd SRC_HDRS := bpf.h libbpf.h btf.h libbpf_common.h libbpf_legacy.h xsk.h \ bpf_helpers.h bpf_tracing.h bpf_endian.h bpf_core_read.h \ - skel_internal.h libbpf_version.h + skel_internal.h libbpf_version.h usdt.bpf.h GEN_HDRS := $(BPF_GENERATED) INSTALL_PFX := $(DESTDIR)$(prefix)/include/bpf diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 1383e26c5d1f..d124e9e533f0 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -2826,10 +2826,8 @@ struct btf_ext *btf_ext__new(const __u8 *data, __u32 size) if (err) goto done; - if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, core_relo_len)) { - err = -EINVAL; - goto done; - } + if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, core_relo_len)) + goto done; /* skip core relos parsing */ err = btf_ext_setup_core_relos(btf_ext); if (err) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 809fe209cdcc..465b7c0996f1 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -483,6 +483,8 @@ struct elf_state { int st_ops_shndx; }; +struct usdt_manager; + struct bpf_object { char name[BPF_OBJ_NAME_LEN]; char license[64]; @@ -545,6 +547,8 @@ struct bpf_object { size_t fd_array_cap; size_t fd_array_cnt; + struct usdt_manager *usdt_man; + char path[]; }; @@ -1397,8 +1401,11 @@ static int find_elf_var_offset(const struct bpf_object *obj, const char *name, _ for (si = 0; si < symbols->d_size / sizeof(Elf64_Sym); si++) { Elf64_Sym *sym = elf_sym_by_idx(obj, si); - if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL || - ELF64_ST_TYPE(sym->st_info) != STT_OBJECT) + if (ELF64_ST_TYPE(sym->st_info) != STT_OBJECT) + continue; + + if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL && + ELF64_ST_BIND(sym->st_info) != STB_WEAK) continue; sname = elf_sym_str(obj, sym->st_name); @@ -4678,6 +4685,18 @@ static int probe_perf_link(void) return link_fd < 0 && err == -EBADF; } +static int probe_kern_bpf_cookie(void) +{ + struct bpf_insn insns[] = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_attach_cookie), + BPF_EXIT_INSN(), + }; + int ret, insn_cnt = ARRAY_SIZE(insns); + + ret = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, "GPL", insns, insn_cnt, NULL); + return probe_fd(ret); +} + enum kern_feature_result { FEAT_UNKNOWN = 0, FEAT_SUPPORTED = 1, @@ -4740,6 +4759,9 @@ static struct kern_feature_desc { [FEAT_MEMCG_ACCOUNT] = { "memcg-based memory accounting", probe_memcg_account, }, + [FEAT_BPF_COOKIE] = { + "BPF cookie support", probe_kern_bpf_cookie, + }, }; bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id) @@ -5665,10 +5687,17 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) insn_idx = rec->insn_off / BPF_INSN_SZ; prog = find_prog_by_sec_insn(obj, sec_idx, insn_idx); if (!prog) { - pr_warn("sec '%s': failed to find program at insn #%d for CO-RE offset relocation #%d\n", - sec_name, insn_idx, i); - err = -EINVAL; - goto out; + /* When __weak subprog is "overridden" by another instance + * of the subprog from a different object file, linker still + * appends all the .BTF.ext info that used to belong to that + * eliminated subprogram. + * This is similar to what x86-64 linker does for relocations. + * So just ignore such relocations just like we ignore + * subprog instructions when discovering subprograms. + */ + pr_debug("sec '%s': skipping CO-RE relocation #%d for insn #%d belonging to eliminated weak subprogram\n", + sec_name, i, insn_idx); + continue; } /* no need to apply CO-RE relocation if the program is * not going to be loaded @@ -8200,6 +8229,9 @@ void bpf_object__close(struct bpf_object *obj) if (obj->clear_priv) obj->clear_priv(obj, obj->priv); + usdt_manager_free(obj->usdt_man); + obj->usdt_man = NULL; + bpf_gen__free(obj->gen_loader); bpf_object__elf_finish(obj); bpf_object_unload(obj); @@ -8630,6 +8662,8 @@ int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log } static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_uprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_usdt(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_raw_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_trace(const struct bpf_program *prog, long cookie, struct bpf_link **link); @@ -8642,11 +8676,12 @@ static const struct bpf_sec_def section_defs[] = { SEC_DEF("sk_reuseport/migrate", SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, SEC_ATTACHABLE | SEC_SLOPPY_PFX), SEC_DEF("sk_reuseport", SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX), SEC_DEF("kprobe/", KPROBE, 0, SEC_NONE, attach_kprobe), - SEC_DEF("uprobe/", KPROBE, 0, SEC_NONE), + SEC_DEF("uprobe+", KPROBE, 0, SEC_NONE, attach_uprobe), SEC_DEF("kretprobe/", KPROBE, 0, SEC_NONE, attach_kprobe), - SEC_DEF("uretprobe/", KPROBE, 0, SEC_NONE), + SEC_DEF("uretprobe+", KPROBE, 0, SEC_NONE, attach_uprobe), SEC_DEF("kprobe.multi/", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), SEC_DEF("kretprobe.multi/", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), + SEC_DEF("usdt+", KPROBE, 0, SEC_NONE, attach_usdt), SEC_DEF("tc", SCHED_CLS, 0, SEC_NONE), SEC_DEF("classifier", SCHED_CLS, 0, SEC_NONE | SEC_SLOPPY_PFX | SEC_DEPRECATED), SEC_DEF("action", SCHED_ACT, 0, SEC_NONE | SEC_SLOPPY_PFX), @@ -9692,14 +9727,6 @@ int bpf_prog_load_deprecated(const char *file, enum bpf_prog_type type, return bpf_prog_load_xattr2(&attr, pobj, prog_fd); } -struct bpf_link { - int (*detach)(struct bpf_link *link); - void (*dealloc)(struct bpf_link *link); - char *pin_path; /* NULL, if not pinned */ - int fd; /* hook FD, -1 if not applicable */ - bool disconnected; -}; - /* Replace link's underlying BPF program with the new one */ int bpf_link__update_program(struct bpf_link *link, struct bpf_program *prog) { @@ -10517,6 +10544,273 @@ static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe, return pfd; } +/* uprobes deal in relative offsets; subtract the base address associated with + * the mapped binary. See Documentation/trace/uprobetracer.rst for more + * details. + */ +static long elf_find_relative_offset(const char *filename, Elf *elf, long addr) +{ + size_t n; + int i; + + if (elf_getphdrnum(elf, &n)) { + pr_warn("elf: failed to find program headers for '%s': %s\n", filename, + elf_errmsg(-1)); + return -ENOENT; + } + + for (i = 0; i < n; i++) { + int seg_start, seg_end, seg_offset; + GElf_Phdr phdr; + + if (!gelf_getphdr(elf, i, &phdr)) { + pr_warn("elf: failed to get program header %d from '%s': %s\n", i, filename, + elf_errmsg(-1)); + return -ENOENT; + } + if (phdr.p_type != PT_LOAD || !(phdr.p_flags & PF_X)) + continue; + + seg_start = phdr.p_vaddr; + seg_end = seg_start + phdr.p_memsz; + seg_offset = phdr.p_offset; + if (addr >= seg_start && addr < seg_end) + return addr - seg_start + seg_offset; + } + pr_warn("elf: failed to find prog header containing 0x%lx in '%s'\n", addr, filename); + return -ENOENT; +} + +/* Return next ELF section of sh_type after scn, or first of that type if scn is NULL. */ +static Elf_Scn *elf_find_next_scn_by_type(Elf *elf, int sh_type, Elf_Scn *scn) +{ + while ((scn = elf_nextscn(elf, scn)) != NULL) { + GElf_Shdr sh; + + if (!gelf_getshdr(scn, &sh)) + continue; + if (sh.sh_type == sh_type) + return scn; + } + return NULL; +} + +/* Find offset of function name in object specified by path. "name" matches + * symbol name or name@@LIB for library functions. + */ +static long elf_find_func_offset(const char *binary_path, const char *name) +{ + int fd, i, sh_types[2] = { SHT_DYNSYM, SHT_SYMTAB }; + bool is_shared_lib, is_name_qualified; + char errmsg[STRERR_BUFSIZE]; + long ret = -ENOENT; + size_t name_len; + GElf_Ehdr ehdr; + Elf *elf; + + fd = open(binary_path, O_RDONLY | O_CLOEXEC); + if (fd < 0) { + ret = -errno; + pr_warn("failed to open %s: %s\n", binary_path, + libbpf_strerror_r(ret, errmsg, sizeof(errmsg))); + return ret; + } + elf = elf_begin(fd, ELF_C_READ_MMAP, NULL); + if (!elf) { + pr_warn("elf: could not read elf from %s: %s\n", binary_path, elf_errmsg(-1)); + close(fd); + return -LIBBPF_ERRNO__FORMAT; + } + if (!gelf_getehdr(elf, &ehdr)) { + pr_warn("elf: failed to get ehdr from %s: %s\n", binary_path, elf_errmsg(-1)); + ret = -LIBBPF_ERRNO__FORMAT; + goto out; + } + /* for shared lib case, we do not need to calculate relative offset */ + is_shared_lib = ehdr.e_type == ET_DYN; + + name_len = strlen(name); + /* Does name specify "@@LIB"? */ + is_name_qualified = strstr(name, "@@") != NULL; + + /* Search SHT_DYNSYM, SHT_SYMTAB for symbol. This search order is used because if + * a binary is stripped, it may only have SHT_DYNSYM, and a fully-statically + * linked binary may not have SHT_DYMSYM, so absence of a section should not be + * reported as a warning/error. + */ + for (i = 0; i < ARRAY_SIZE(sh_types); i++) { + size_t nr_syms, strtabidx, idx; + Elf_Data *symbols = NULL; + Elf_Scn *scn = NULL; + int last_bind = -1; + const char *sname; + GElf_Shdr sh; + + scn = elf_find_next_scn_by_type(elf, sh_types[i], NULL); + if (!scn) { + pr_debug("elf: failed to find symbol table ELF sections in '%s'\n", + binary_path); + continue; + } + if (!gelf_getshdr(scn, &sh)) + continue; + strtabidx = sh.sh_link; + symbols = elf_getdata(scn, 0); + if (!symbols) { + pr_warn("elf: failed to get symbols for symtab section in '%s': %s\n", + binary_path, elf_errmsg(-1)); + ret = -LIBBPF_ERRNO__FORMAT; + goto out; + } + nr_syms = symbols->d_size / sh.sh_entsize; + + for (idx = 0; idx < nr_syms; idx++) { + int curr_bind; + GElf_Sym sym; + + if (!gelf_getsym(symbols, idx, &sym)) + continue; + + if (GELF_ST_TYPE(sym.st_info) != STT_FUNC) + continue; + + sname = elf_strptr(elf, strtabidx, sym.st_name); + if (!sname) + continue; + + curr_bind = GELF_ST_BIND(sym.st_info); + + /* User can specify func, func@@LIB or func@@LIB_VERSION. */ + if (strncmp(sname, name, name_len) != 0) + continue; + /* ...but we don't want a search for "foo" to match 'foo2" also, so any + * additional characters in sname should be of the form "@@LIB". + */ + if (!is_name_qualified && sname[name_len] != '\0' && sname[name_len] != '@') + continue; + + if (ret >= 0) { + /* handle multiple matches */ + if (last_bind != STB_WEAK && curr_bind != STB_WEAK) { + /* Only accept one non-weak bind. */ + pr_warn("elf: ambiguous match for '%s', '%s' in '%s'\n", + sname, name, binary_path); + ret = -LIBBPF_ERRNO__FORMAT; + goto out; + } else if (curr_bind == STB_WEAK) { + /* already have a non-weak bind, and + * this is a weak bind, so ignore. + */ + continue; + } + } + ret = sym.st_value; + last_bind = curr_bind; + } + /* For binaries that are not shared libraries, we need relative offset */ + if (ret > 0 && !is_shared_lib) + ret = elf_find_relative_offset(binary_path, elf, ret); + if (ret > 0) + break; + } + + if (ret > 0) { + pr_debug("elf: symbol address match for '%s' in '%s': 0x%lx\n", name, binary_path, + ret); + } else { + if (ret == 0) { + pr_warn("elf: '%s' is 0 in symtab for '%s': %s\n", name, binary_path, + is_shared_lib ? "should not be 0 in a shared library" : + "try using shared library path instead"); + ret = -ENOENT; + } else { + pr_warn("elf: failed to find symbol '%s' in '%s'\n", name, binary_path); + } + } +out: + elf_end(elf); + close(fd); + return ret; +} + +static const char *arch_specific_lib_paths(void) +{ + /* + * Based on https://packages.debian.org/sid/libc6. + * + * Assume that the traced program is built for the same architecture + * as libbpf, which should cover the vast majority of cases. + */ +#if defined(__x86_64__) + return "/lib/x86_64-linux-gnu"; +#elif defined(__i386__) + return "/lib/i386-linux-gnu"; +#elif defined(__s390x__) + return "/lib/s390x-linux-gnu"; +#elif defined(__s390__) + return "/lib/s390-linux-gnu"; +#elif defined(__arm__) && defined(__SOFTFP__) + return "/lib/arm-linux-gnueabi"; +#elif defined(__arm__) && !defined(__SOFTFP__) + return "/lib/arm-linux-gnueabihf"; +#elif defined(__aarch64__) + return "/lib/aarch64-linux-gnu"; +#elif defined(__mips__) && defined(__MIPSEL__) && _MIPS_SZLONG == 64 + return "/lib/mips64el-linux-gnuabi64"; +#elif defined(__mips__) && defined(__MIPSEL__) && _MIPS_SZLONG == 32 + return "/lib/mipsel-linux-gnu"; +#elif defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + return "/lib/powerpc64le-linux-gnu"; +#elif defined(__sparc__) && defined(__arch64__) + return "/lib/sparc64-linux-gnu"; +#elif defined(__riscv) && __riscv_xlen == 64 + return "/lib/riscv64-linux-gnu"; +#else + return NULL; +#endif +} + +/* Get full path to program/shared library. */ +static int resolve_full_path(const char *file, char *result, size_t result_sz) +{ + const char *search_paths[3] = {}; + int i; + + if (str_has_sfx(file, ".so") || strstr(file, ".so.")) { + search_paths[0] = getenv("LD_LIBRARY_PATH"); + search_paths[1] = "/usr/lib64:/usr/lib"; + search_paths[2] = arch_specific_lib_paths(); + } else { + search_paths[0] = getenv("PATH"); + search_paths[1] = "/usr/bin:/usr/sbin"; + } + + for (i = 0; i < ARRAY_SIZE(search_paths); i++) { + const char *s; + + if (!search_paths[i]) + continue; + for (s = search_paths[i]; s != NULL; s = strchr(s, ':')) { + char *next_path; + int seg_len; + + if (s[0] == ':') + s++; + next_path = strchr(s, ':'); + seg_len = next_path ? next_path - s : strlen(s); + if (!seg_len) + continue; + snprintf(result, result_sz, "%.*s/%s", seg_len, s, file); + /* ensure it is an executable file/link */ + if (access(result, R_OK | X_OK) < 0) + continue; + pr_debug("resolved '%s' to '%s'\n", file, result); + return 0; + } + } + return -ENOENT; +} + LIBBPF_API struct bpf_link * bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, const char *binary_path, size_t func_offset, @@ -10524,10 +10818,12 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, { DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); char errmsg[STRERR_BUFSIZE], *legacy_probe = NULL; + char full_binary_path[PATH_MAX]; struct bpf_link *link; size_t ref_ctr_off; int pfd, err; bool retprobe, legacy; + const char *func_name; if (!OPTS_VALID(opts, bpf_uprobe_opts)) return libbpf_err_ptr(-EINVAL); @@ -10536,12 +10832,37 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0); pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); + if (binary_path && !strchr(binary_path, '/')) { + err = resolve_full_path(binary_path, full_binary_path, + sizeof(full_binary_path)); + if (err) { + pr_warn("prog '%s': failed to resolve full path for '%s': %d\n", + prog->name, binary_path, err); + return libbpf_err_ptr(err); + } + binary_path = full_binary_path; + } + func_name = OPTS_GET(opts, func_name, NULL); + if (func_name) { + long sym_off; + + if (!binary_path) { + pr_warn("prog '%s': name-based attach requires binary_path\n", + prog->name); + return libbpf_err_ptr(-EINVAL); + } + sym_off = elf_find_func_offset(binary_path, func_name); + if (sym_off < 0) + return libbpf_err_ptr(sym_off); + func_offset += sym_off; + } + legacy = determine_uprobe_perf_type() < 0; if (!legacy) { pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path, func_offset, pid, ref_ctr_off); } else { - char probe_name[512]; + char probe_name[PATH_MAX + 64]; if (ref_ctr_off) return libbpf_err_ptr(-EINVAL); @@ -10589,6 +10910,60 @@ err_out: } +/* Format of u[ret]probe section definition supporting auto-attach: + * u[ret]probe/binary:function[+offset] + * + * binary can be an absolute/relative path or a filename; the latter is resolved to a + * full binary path via bpf_program__attach_uprobe_opts. + * + * Specifying uprobe+ ensures we carry out strict matching; either "uprobe" must be + * specified (and auto-attach is not possible) or the above format is specified for + * auto-attach. + */ +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; + 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); + switch (n) { + case 1: + /* handle SEC("u[ret]probe") - format is valid, but auto-attach is impossible. */ + ret = 0; + break; + case 2: + pr_warn("prog '%s': section '%s' missing ':function[+offset]' specification\n", + prog->name, prog->sec_name); + break; + case 3: + case 4: + opts.retprobe = strcmp(probe_type, "uretprobe") == 0; + if (opts.retprobe && offset != 0) { + pr_warn("prog '%s': uretprobes do not support offset specification\n", + prog->name); + break; + } + opts.func_name = func_name; + *link = bpf_program__attach_uprobe_opts(prog, -1, binary_path, offset, &opts); + ret = libbpf_get_error(*link); + break; + default: + pr_warn("prog '%s': invalid format of section definition '%s'\n", prog->name, + prog->sec_name); + break; + } + free(probe_type); + free(binary_path); + free(func_name); + + return ret; +} + struct bpf_link *bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe, pid_t pid, const char *binary_path, @@ -10599,6 +10974,85 @@ struct bpf_link *bpf_program__attach_uprobe(const struct bpf_program *prog, return bpf_program__attach_uprobe_opts(prog, pid, binary_path, func_offset, &opts); } +struct bpf_link *bpf_program__attach_usdt(const struct bpf_program *prog, + pid_t pid, const char *binary_path, + const char *usdt_provider, const char *usdt_name, + const struct bpf_usdt_opts *opts) +{ + char resolved_path[512]; + struct bpf_object *obj = prog->obj; + struct bpf_link *link; + long usdt_cookie; + int err; + + if (!OPTS_VALID(opts, bpf_uprobe_opts)) + return libbpf_err_ptr(-EINVAL); + + if (bpf_program__fd(prog) < 0) { + pr_warn("prog '%s': can't attach BPF program w/o FD (did you load it?)\n", + prog->name); + return libbpf_err_ptr(-EINVAL); + } + + if (!strchr(binary_path, '/')) { + err = resolve_full_path(binary_path, resolved_path, sizeof(resolved_path)); + if (err) { + pr_warn("prog '%s': failed to resolve full path for '%s': %d\n", + prog->name, binary_path, err); + return libbpf_err_ptr(err); + } + binary_path = resolved_path; + } + + /* USDT manager is instantiated lazily on first USDT attach. It will + * be destroyed together with BPF object in bpf_object__close(). + */ + if (IS_ERR(obj->usdt_man)) + return libbpf_ptr(obj->usdt_man); + if (!obj->usdt_man) { + obj->usdt_man = usdt_manager_new(obj); + if (IS_ERR(obj->usdt_man)) + return libbpf_ptr(obj->usdt_man); + } + + usdt_cookie = OPTS_GET(opts, usdt_cookie, 0); + link = usdt_manager_attach_usdt(obj->usdt_man, prog, pid, binary_path, + usdt_provider, usdt_name, usdt_cookie); + err = libbpf_get_error(link); + if (err) + return libbpf_err_ptr(err); + return link; +} + +static int attach_usdt(const struct bpf_program *prog, long cookie, struct bpf_link **link) +{ + char *path = NULL, *provider = NULL, *name = NULL; + const char *sec_name; + int n, err; + + sec_name = bpf_program__section_name(prog); + if (strcmp(sec_name, "usdt") == 0) { + /* no auto-attach for just SEC("usdt") */ + *link = NULL; + return 0; + } + + n = sscanf(sec_name, "usdt/%m[^:]:%m[^:]:%m[^:]", &path, &provider, &name); + if (n != 3) { + pr_warn("invalid section '%s', expected SEC(\"usdt/<path>:<provider>:<name>\")\n", + sec_name); + err = -EINVAL; + } else { + *link = bpf_program__attach_usdt(prog, -1 /* any process */, path, + provider, name, NULL); + err = libbpf_get_error(*link); + } + free(path); + free(provider); + free(name); + return err; +} + static int determine_tracepoint_id(const char *tp_category, const char *tp_name) { diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 05dde85e19a6..63d66f1adf1a 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -459,9 +459,17 @@ struct bpf_uprobe_opts { __u64 bpf_cookie; /* uprobe is return probe, invoked at function return time */ bool retprobe; + /* Function name to attach to. Could be an unqualified ("abc") or library-qualified + * "abc@LIBXYZ" name. To specify function entry, func_name should be set while + * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an + * offset within a function, specify func_name and use func_offset argument to specify + * offset within the function. Shared library functions must specify the shared library + * binary_path. + */ + const char *func_name; size_t :0; }; -#define bpf_uprobe_opts__last_field retprobe +#define bpf_uprobe_opts__last_field func_name /** * @brief **bpf_program__attach_uprobe()** attaches a BPF program @@ -503,6 +511,37 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, const char *binary_path, size_t func_offset, const struct bpf_uprobe_opts *opts); +struct bpf_usdt_opts { + /* size of this struct, for forward/backward compatibility */ + size_t sz; + /* custom user-provided value accessible through usdt_cookie() */ + __u64 usdt_cookie; + size_t :0; +}; +#define bpf_usdt_opts__last_field usdt_cookie + +/** + * @brief **bpf_program__attach_usdt()** is just like + * bpf_program__attach_uprobe_opts() except it covers USDT (User-space + * Statically Defined Tracepoint) attachment, instead of attaching to + * user-space function entry or exit. + * + * @param prog BPF program to attach + * @param pid Process ID to attach the uprobe to, 0 for self (own process), + * -1 for all processes + * @param binary_path Path to binary that contains provided USDT probe + * @param usdt_provider USDT provider name + * @param usdt_name USDT probe name + * @param opts Options for altering program attachment + * @return Reference to the newly created BPF link; or NULL is returned on error, + * error code is stored in errno + */ +LIBBPF_API struct bpf_link * +bpf_program__attach_usdt(const struct bpf_program *prog, + pid_t pid, const char *binary_path, + const char *usdt_provider, const char *usdt_name, + const struct bpf_usdt_opts *opts); + struct bpf_tracepoint_opts { /* size of this struct, for forward/backward compatiblity */ size_t sz; diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index dd35ee58bfaa..82f6d62176dd 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -444,6 +444,7 @@ LIBBPF_0.8.0 { global: bpf_object__destroy_subskeleton; bpf_object__open_subskeleton; + bpf_program__attach_usdt; libbpf_register_prog_handler; libbpf_unregister_prog_handler; bpf_program__attach_kprobe_multi_opts; diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index b6247dc7f8eb..080272421f6c 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -103,6 +103,17 @@ #define str_has_pfx(str, pfx) \ (strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0) +/* suffix check */ +static inline bool str_has_sfx(const char *str, const char *sfx) +{ + size_t str_len = strlen(str); + size_t sfx_len = strlen(sfx); + + if (sfx_len <= str_len) + return strcmp(str + str_len - sfx_len, sfx); + return false; +} + /* Symbol versioning is different between static and shared library. * Properly versioned symbols are needed for shared library, but * only the symbol of the new version is needed for static library. @@ -148,6 +159,15 @@ do { \ #ifndef __has_builtin #define __has_builtin(x) 0 #endif + +struct bpf_link { + int (*detach)(struct bpf_link *link); + void (*dealloc)(struct bpf_link *link); + char *pin_path; /* NULL, if not pinned */ + int fd; /* hook FD, -1 if not applicable */ + bool disconnected; +}; + /* * Re-implement glibc's reallocarray() for libbpf internal-only use. * reallocarray(), unfortunately, is not available in all versions of glibc, @@ -329,6 +349,8 @@ enum kern_feature_id { FEAT_BTF_TYPE_TAG, /* memcg-based accounting for BPF maps and progs */ FEAT_MEMCG_ACCOUNT, + /* BPF cookie (bpf_get_attach_cookie() BPF helper) support */ + FEAT_BPF_COOKIE, __FEAT_CNT, }; @@ -543,4 +565,12 @@ int bpf_core_add_cands(struct bpf_core_cand *local_cand, struct bpf_core_cand_list *cands); void bpf_core_free_cands(struct bpf_core_cand_list *cands); +struct usdt_manager *usdt_manager_new(struct bpf_object *obj); +void usdt_manager_free(struct usdt_manager *man); +struct bpf_link * usdt_manager_attach_usdt(struct usdt_manager *man, + const struct bpf_program *prog, + pid_t pid, const char *path, + const char *usdt_provider, const char *usdt_name, + long usdt_cookie); + #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ diff --git a/tools/lib/bpf/usdt.bpf.h b/tools/lib/bpf/usdt.bpf.h new file mode 100644 index 000000000000..4181fddb3687 --- /dev/null +++ b/tools/lib/bpf/usdt.bpf.h @@ -0,0 +1,259 @@ +/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ +#ifndef __USDT_BPF_H__ +#define __USDT_BPF_H__ + +#include <linux/errno.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_core_read.h> + +/* Below types and maps are internal implementation details of libbpf's USDT + * support and are subjects to change. Also, bpf_usdt_xxx() API helpers should + * be considered an unstable API as well and might be adjusted based on user + * feedback from using libbpf's USDT support in production. + */ + +/* User can override BPF_USDT_MAX_SPEC_CNT to change default size of internal + * map that keeps track of USDT argument specifications. This might be + * necessary if there are a lot of USDT attachments. + */ +#ifndef BPF_USDT_MAX_SPEC_CNT +#define BPF_USDT_MAX_SPEC_CNT 256 +#endif +/* User can override BPF_USDT_MAX_IP_CNT to change default size of internal + * map that keeps track of IP (memory address) mapping to USDT argument + * specification. + * Note, if kernel supports BPF cookies, this map is not used and could be + * resized all the way to 1 to save a bit of memory. + */ +#ifndef BPF_USDT_MAX_IP_CNT +#define BPF_USDT_MAX_IP_CNT (4 * BPF_USDT_MAX_SPEC_CNT) +#endif +/* We use BPF CO-RE to detect support for BPF cookie from BPF side. This is + * the only dependency on CO-RE, so if it's undesirable, user can override + * BPF_USDT_HAS_BPF_COOKIE to specify whether to BPF cookie is supported or not. + */ +#ifndef BPF_USDT_HAS_BPF_COOKIE +#define BPF_USDT_HAS_BPF_COOKIE \ + bpf_core_enum_value_exists(enum bpf_func_id___usdt, BPF_FUNC_get_attach_cookie___usdt) +#endif + +enum __bpf_usdt_arg_type { + BPF_USDT_ARG_CONST, + BPF_USDT_ARG_REG, + BPF_USDT_ARG_REG_DEREF, +}; + +struct __bpf_usdt_arg_spec { + /* u64 scalar interpreted depending on arg_type, see below */ + __u64 val_off; + /* arg location case, see bpf_udst_arg() for details */ + enum __bpf_usdt_arg_type arg_type; + /* offset of referenced register within struct pt_regs */ + short reg_off; + /* whether arg should be interpreted as signed value */ + bool arg_signed; + /* number of bits that need to be cleared and, optionally, + * sign-extended to cast arguments that are 1, 2, or 4 bytes + * long into final 8-byte u64/s64 value returned to user + */ + char arg_bitshift; +}; + +/* should match USDT_MAX_ARG_CNT in usdt.c exactly */ +#define BPF_USDT_MAX_ARG_CNT 12 +struct __bpf_usdt_spec { + struct __bpf_usdt_arg_spec args[BPF_USDT_MAX_ARG_CNT]; + __u64 usdt_cookie; + short arg_cnt; +}; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, BPF_USDT_MAX_SPEC_CNT); + __type(key, int); + __type(value, struct __bpf_usdt_spec); +} __bpf_usdt_specs SEC(".maps") __weak; + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, BPF_USDT_MAX_IP_CNT); + __type(key, long); + __type(value, __u32); +} __bpf_usdt_ip_to_spec_id SEC(".maps") __weak; + +/* don't rely on user's BPF code to have latest definition of bpf_func_id */ +enum bpf_func_id___usdt { + BPF_FUNC_get_attach_cookie___usdt = 0xBAD, /* value doesn't matter */ +}; + +static __always_inline +int __bpf_usdt_spec_id(struct pt_regs *ctx) +{ + if (!BPF_USDT_HAS_BPF_COOKIE) { + long ip = PT_REGS_IP(ctx); + int *spec_id_ptr; + + spec_id_ptr = bpf_map_lookup_elem(&__bpf_usdt_ip_to_spec_id, &ip); + return spec_id_ptr ? *spec_id_ptr : -ESRCH; + } + + return bpf_get_attach_cookie(ctx); +} + +/* Return number of USDT arguments defined for currently traced USDT. */ +__weak __hidden +int bpf_usdt_arg_cnt(struct pt_regs *ctx) +{ + struct __bpf_usdt_spec *spec; + int spec_id; + + spec_id = __bpf_usdt_spec_id(ctx); + if (spec_id < 0) + return -ESRCH; + + spec = bpf_map_lookup_elem(&__bpf_usdt_specs, &spec_id); + if (!spec) + return -ESRCH; + + return spec->arg_cnt; +} + +/* Fetch USDT argument #*arg_num* (zero-indexed) and put its value into *res. + * Returns 0 on success; negative error, otherwise. + * On error *res is guaranteed to be set to zero. + */ +__weak __hidden +int bpf_usdt_arg(struct pt_regs *ctx, __u64 arg_num, long *res) +{ + struct __bpf_usdt_spec *spec; + struct __bpf_usdt_arg_spec *arg_spec; + unsigned long val; + int err, spec_id; + + *res = 0; + + spec_id = __bpf_usdt_spec_id(ctx); + if (spec_id < 0) + return -ESRCH; + + spec = bpf_map_lookup_elem(&__bpf_usdt_specs, &spec_id); + if (!spec) + return -ESRCH; + + if (arg_num >= BPF_USDT_MAX_ARG_CNT || arg_num >= spec->arg_cnt) + return -ENOENT; + + arg_spec = &spec->args[arg_num]; + switch (arg_spec->arg_type) { + case BPF_USDT_ARG_CONST: + /* Arg is just a constant ("-4@$-9" in USDT arg spec). + * value is recorded in arg_spec->val_off directly. + */ + val = arg_spec->val_off; + break; + case BPF_USDT_ARG_REG: + /* Arg is in a register (e.g, "8@%rax" in USDT arg spec), + * so we read the contents of that register directly from + * struct pt_regs. To keep things simple user-space parts + * record offsetof(struct pt_regs, <regname>) in arg_spec->reg_off. + */ + err = bpf_probe_read_kernel(&val, sizeof(val), (void *)ctx + arg_spec->reg_off); + if (err) + return err; + break; + case BPF_USDT_ARG_REG_DEREF: + /* Arg is in memory addressed by register, plus some offset + * (e.g., "-4@-1204(%rbp)" in USDT arg spec). Register is + * identified like with BPF_USDT_ARG_REG case, and the offset + * is in arg_spec->val_off. We first fetch register contents + * from pt_regs, then do another user-space probe read to + * fetch argument value itself. + */ + err = bpf_probe_read_kernel(&val, sizeof(val), (void *)ctx + arg_spec->reg_off); + if (err) + return err; + err = bpf_probe_read_user(&val, sizeof(val), (void *)val + arg_spec->val_off); + if (err) + return err; +#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ + val >>= arg_spec->arg_bitshift; +#endif + break; + default: + return -EINVAL; + } + + /* cast arg from 1, 2, or 4 bytes to final 8 byte size clearing + * necessary upper arg_bitshift bits, with sign extension if argument + * is signed + */ + val <<= arg_spec->arg_bitshift; + if (arg_spec->arg_signed) + val = ((long)val) >> arg_spec->arg_bitshift; + else + val = val >> arg_spec->arg_bitshift; + *res = val; + return 0; +} + +/* Retrieve user-specified cookie value provided during attach as + * bpf_usdt_opts.usdt_cookie. This serves the same purpose as BPF cookie + * returned by bpf_get_attach_cookie(). Libbpf's support for USDT is itself + * utilizing BPF cookies internally, so user can't use BPF cookie directly + * for USDT programs and has to use bpf_usdt_cookie() API instead. + */ +__weak __hidden +long bpf_usdt_cookie(struct pt_regs *ctx) +{ + struct __bpf_usdt_spec *spec; + int spec_id; + + spec_id = __bpf_usdt_spec_id(ctx); + if (spec_id < 0) + return 0; + + spec = bpf_map_lookup_elem(&__bpf_usdt_specs, &spec_id); + if (!spec) + return 0; + + return spec->usdt_cookie; +} + +/* we rely on ___bpf_apply() and ___bpf_narg() macros already defined in bpf_tracing.h */ +#define ___bpf_usdt_args0() ctx +#define ___bpf_usdt_args1(x) ___bpf_usdt_args0(), ({ long _x; bpf_usdt_arg(ctx, 0, &_x); (void *)_x; }) +#define ___bpf_usdt_args2(x, args...) ___bpf_usdt_args1(args), ({ long _x; bpf_usdt_arg(ctx, 1, &_x); (void *)_x; }) +#define ___bpf_usdt_args3(x, args...) ___bpf_usdt_args2(args), ({ long _x; bpf_usdt_arg(ctx, 2, &_x); (void *)_x; }) +#define ___bpf_usdt_args4(x, args...) ___bpf_usdt_args3(args), ({ long _x; bpf_usdt_arg(ctx, 3, &_x); (void *)_x; }) +#define ___bpf_usdt_args5(x, args...) ___bpf_usdt_args4(args), ({ long _x; bpf_usdt_arg(ctx, 4, &_x); (void *)_x; }) +#define ___bpf_usdt_args6(x, args...) ___bpf_usdt_args5(args), ({ long _x; bpf_usdt_arg(ctx, 5, &_x); (void *)_x; }) +#define ___bpf_usdt_args7(x, args...) ___bpf_usdt_args6(args), ({ long _x; bpf_usdt_arg(ctx, 6, &_x); (void *)_x; }) +#define ___bpf_usdt_args8(x, args...) ___bpf_usdt_args7(args), ({ long _x; bpf_usdt_arg(ctx, 7, &_x); (void *)_x; }) +#define ___bpf_usdt_args9(x, args...) ___bpf_usdt_args8(args), ({ long _x; bpf_usdt_arg(ctx, 8, &_x); (void *)_x; }) +#define ___bpf_usdt_args10(x, args...) ___bpf_usdt_args9(args), ({ long _x; bpf_usdt_arg(ctx, 9, &_x); (void *)_x; }) +#define ___bpf_usdt_args11(x, args...) ___bpf_usdt_args10(args), ({ long _x; bpf_usdt_arg(ctx, 10, &_x); (void *)_x; }) +#define ___bpf_usdt_args12(x, args...) ___bpf_usdt_args11(args), ({ long _x; bpf_usdt_arg(ctx, 11, &_x); (void *)_x; }) +#define ___bpf_usdt_args(args...) ___bpf_apply(___bpf_usdt_args, ___bpf_narg(args))(args) + +/* + * BPF_USDT serves the same purpose for USDT handlers as BPF_PROG for + * tp_btf/fentry/fexit BPF programs and BPF_KPROBE for kprobes. + * Original struct pt_regs * context is preserved as 'ctx' argument. + */ +#define BPF_USDT(name, args...) \ +name(struct pt_regs *ctx); \ +static __attribute__((always_inline)) typeof(name(0)) \ +____##name(struct pt_regs *ctx, ##args); \ +typeof(name(0)) name(struct pt_regs *ctx) \ +{ \ + _Pragma("GCC diagnostic push") \ + _Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \ + return ____##name(___bpf_usdt_args(args)); \ + _Pragma("GCC diagnostic pop") \ +} \ +static __attribute__((always_inline)) typeof(name(0)) \ +____##name(struct pt_regs *ctx, ##args) + +#endif /* __USDT_BPF_H__ */ diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c new file mode 100644 index 000000000000..acf2d99a9e77 --- /dev/null +++ b/tools/lib/bpf/usdt.c @@ -0,0 +1,1335 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ +#include <ctype.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <libelf.h> +#include <gelf.h> +#include <unistd.h> +#include <linux/ptrace.h> +#include <linux/kernel.h> + +#include "bpf.h" +#include "libbpf.h" +#include "libbpf_common.h" +#include "libbpf_internal.h" +#include "hashmap.h" + +/* libbpf's USDT support consists of BPF-side state/code and user-space + * state/code working together in concert. BPF-side parts are defined in + * usdt.bpf.h header library. User-space state is encapsulated by struct + * usdt_manager and all the supporting code centered around usdt_manager. + * + * usdt.bpf.h defines two BPF maps that usdt_manager expects: USDT spec map + * and IP-to-spec-ID map, which is auxiliary map necessary for kernels that + * don't support BPF cookie (see below). These two maps are implicitly + * embedded into user's end BPF object file when user's code included + * usdt.bpf.h. This means that libbpf doesn't do anything special to create + * these USDT support maps. They are created by normal libbpf logic of + * instantiating BPF maps when opening and loading BPF object. + * + * As such, libbpf is basically unaware of the need to do anything + * USDT-related until the very first call to bpf_program__attach_usdt(), which + * can be called by user explicitly or happen automatically during skeleton + * attach (or, equivalently, through generic bpf_program__attach() call). At + * this point, libbpf will instantiate and initialize struct usdt_manager and + * store it in bpf_object. USDT manager is per-BPF object construct, as each + * independent BPF object might or might not have USDT programs, and thus all + * the expected USDT-related state. There is no coordination between two + * bpf_object in parts of USDT attachment, they are oblivious of each other's + * existence and libbpf is just oblivious, dealing with bpf_object-specific + * USDT state. + * + * Quick crash course on USDTs. + * + * From user-space application's point of view, USDT is essentially just + * a slightly special function call that normally has zero overhead, unless it + * is being traced by some external entity (e.g, BPF-based tool). Here's how + * a typical application can trigger USDT probe: + * + * #include <sys/sdt.h> // provided by systemtap-sdt-devel package + * // folly also provide similar functionality in folly/tracing/StaticTracepoint.h + * + * STAP_PROBE3(my_usdt_provider, my_usdt_probe_name, 123, x, &y); + * + * USDT is identified by it's <provider-name>:<probe-name> pair of names. Each + * individual USDT has a fixed number of arguments (3 in the above example) + * and specifies values of each argument as if it was a function call. + * + * USDT call is actually not a function call, but is instead replaced by + * a single NOP instruction (thus zero overhead, effectively). But in addition + * to that, those USDT macros generate special SHT_NOTE ELF records in + * .note.stapsdt ELF section. Here's an example USDT definition as emitted by + * `readelf -n <binary>`: + * + * stapsdt 0x00000089 NT_STAPSDT (SystemTap probe descriptors) + * Provider: test + * Name: usdt12 + * Location: 0x0000000000549df3, Base: 0x00000000008effa4, Semaphore: 0x0000000000a4606e + * Arguments: -4@-1204(%rbp) -4@%edi -8@-1216(%rbp) -8@%r8 -4@$5 -8@%r9 8@%rdx 8@%r10 -4@$-9 -2@%cx -2@%ax -1@%sil + * + * In this case we have USDT test:usdt12 with 12 arguments. + * + * Location and base are offsets used to calculate absolute IP address of that + * NOP instruction that kernel can replace with an interrupt instruction to + * trigger instrumentation code (BPF program for all that we care about). + * + * Semaphore above is and optional feature. It records an address of a 2-byte + * refcount variable (normally in '.probes' ELF section) used for signaling if + * there is anything that is attached to USDT. This is useful for user + * applications if, for example, they need to prepare some arguments that are + * passed only to USDTs and preparation is expensive. By checking if USDT is + * "activated", an application can avoid paying those costs unnecessarily. + * Recent enough kernel has built-in support for automatically managing this + * refcount, which libbpf expects and relies on. If USDT is defined without + * associated semaphore, this value will be zero. See selftests for semaphore + * examples. + * + * Arguments is the most interesting part. This USDT specification string is + * providing information about all the USDT arguments and their locations. The + * part before @ sign defined byte size of the argument (1, 2, 4, or 8) and + * whether the argument is signed or unsigned (negative size means signed). + * The part after @ sign is assembly-like definition of argument location + * (see [0] for more details). Technically, assembler can provide some pretty + * advanced definitions, but libbpf is currently supporting three most common + * cases: + * 1) immediate constant, see 5th and 9th args above (-4@$5 and -4@-9); + * 2) register value, e.g., 8@%rdx, which means "unsigned 8-byte integer + * whose value is in register %rdx"; + * 3) memory dereference addressed by register, e.g., -4@-1204(%rbp), which + * specifies signed 32-bit integer stored at offset -1204 bytes from + * memory address stored in %rbp. + * + * [0] https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation + * + * During attachment, libbpf parses all the relevant USDT specifications and + * prepares `struct usdt_spec` (USDT spec), which is then provided to BPF-side + * code through spec map. This allows BPF applications to quickly fetch the + * actual value at runtime using a simple BPF-side code. + * + * With basics out of the way, let's go over less immediately obvious aspects + * of supporting USDTs. + * + * First, there is no special USDT BPF program type. It is actually just + * a uprobe BPF program (which for kernel, at least currently, is just a kprobe + * program, so BPF_PROG_TYPE_KPROBE program type). With the only difference + * that uprobe is usually attached at the function entry, while USDT will + * normally will be somewhere inside the function. But it should always be + * pointing to NOP instruction, which makes such uprobes the fastest uprobe + * kind. + * + * Second, it's important to realize that such STAP_PROBEn(provider, name, ...) + * macro invocations can end up being inlined many-many times, depending on + * specifics of each individual user application. So single conceptual USDT + * (identified by provider:name pair of identifiers) is, generally speaking, + * multiple uprobe locations (USDT call sites) in different places in user + * application. Further, again due to inlining, each USDT call site might end + * up having the same argument #N be located in a different place. In one call + * site it could be a constant, in another will end up in a register, and in + * yet another could be some other register or even somewhere on the stack. + * + * As such, "attaching to USDT" means (in general case) attaching the same + * uprobe BPF program to multiple target locations in user application, each + * potentially having a completely different USDT spec associated with it. + * To wire all this up together libbpf allocates a unique integer spec ID for + * each unique USDT spec. Spec IDs are allocated as sequential small integers + * so that they can be used as keys in array BPF map (for performance reasons). + * Spec ID allocation and accounting is big part of what usdt_manager is + * about. This state has to be maintained per-BPF object and coordinate + * between different USDT attachments within the same BPF object. + * + * Spec ID is the key in spec BPF map, value is the actual USDT spec layed out + * as struct usdt_spec. Each invocation of BPF program at runtime needs to + * know its associated spec ID. It gets it either through BPF cookie, which + * libbpf sets to spec ID during attach time, or, if kernel is too old to + * support BPF cookie, through IP-to-spec-ID map that libbpf maintains in such + * case. The latter means that some modes of operation can't be supported + * without BPF cookie. Such mode is attaching to shared library "generically", + * without specifying target process. In such case, it's impossible to + * calculate absolute IP addresses for IP-to-spec-ID map, and thus such mode + * is not supported without BPF cookie support. + * + * Note that libbpf is using BPF cookie functionality for its own internal + * needs, so user itself can't rely on BPF cookie feature. To that end, libbpf + * provides conceptually equivalent USDT cookie support. It's still u64 + * user-provided value that can be associated with USDT attachment. Note that + * this will be the same value for all USDT call sites within the same single + * *logical* USDT attachment. This makes sense because to user attaching to + * USDT is a single BPF program triggered for singular USDT probe. The fact + * that this is done at multiple actual locations is a mostly hidden + * implementation details. This USDT cookie value can be fetched with + * bpf_usdt_cookie(ctx) API provided by usdt.bpf.h + * + * Lastly, while single USDT can have tons of USDT call sites, it doesn't + * necessarily have that many different USDT specs. It very well might be + * that 1000 USDT call sites only need 5 different USDT specs, because all the + * arguments are typically contained in a small set of registers or stack + * locations. As such, it's wasteful to allocate as many USDT spec IDs as + * there are USDT call sites. So libbpf tries to be frugal and performs + * on-the-fly deduplication during a single USDT attachment to only allocate + * the minimal required amount of unique USDT specs (and thus spec IDs). This + * is trivially achieved by using USDT spec string (Arguments string from USDT + * note) as a lookup key in a hashmap. USDT spec string uniquely defines + * everything about how to fetch USDT arguments, so two USDT call sites + * sharing USDT spec string can safely share the same USDT spec and spec ID. + * Note, this spec string deduplication is happening only during the same USDT + * attachment, so each USDT spec shares the same USDT cookie value. This is + * not generally true for other USDT attachments within the same BPF object, + * as even if USDT spec string is the same, USDT cookie value can be + * different. It was deemed excessive to try to deduplicate across independent + * USDT attachments by taking into account USDT spec string *and* USDT cookie + * value, which would complicated spec ID accounting significantly for little + * gain. + */ + +#define USDT_BASE_SEC ".stapsdt.base" +#define USDT_SEMA_SEC ".probes" +#define USDT_NOTE_SEC ".note.stapsdt" +#define USDT_NOTE_TYPE 3 +#define USDT_NOTE_NAME "stapsdt" + +/* should match exactly enum __bpf_usdt_arg_type from usdt.bpf.h */ +enum usdt_arg_type { + USDT_ARG_CONST, + USDT_ARG_REG, + USDT_ARG_REG_DEREF, +}; + +/* should match exactly struct __bpf_usdt_arg_spec from usdt.bpf.h */ +struct usdt_arg_spec { + __u64 val_off; + enum usdt_arg_type arg_type; + short reg_off; + bool arg_signed; + char arg_bitshift; +}; + +/* should match BPF_USDT_MAX_ARG_CNT in usdt.bpf.h */ +#define USDT_MAX_ARG_CNT 12 + +/* should match struct __bpf_usdt_spec from usdt.bpf.h */ +struct usdt_spec { + struct usdt_arg_spec args[USDT_MAX_ARG_CNT]; + __u64 usdt_cookie; + short arg_cnt; +}; + +struct usdt_note { + const char *provider; + const char *name; + /* USDT args specification string, e.g.: + * "-4@%esi -4@-24(%rbp) -4@%ecx 2@%ax 8@%rdx" + */ + const char *args; + long loc_addr; + long base_addr; + long sema_addr; +}; + +struct usdt_target { + long abs_ip; + long rel_ip; + long sema_off; + struct usdt_spec spec; + const char *spec_str; +}; + +struct usdt_manager { + struct bpf_map *specs_map; + struct bpf_map *ip_to_spec_id_map; + + int *free_spec_ids; + size_t free_spec_cnt; + size_t next_free_spec_id; + + bool has_bpf_cookie; + bool has_sema_refcnt; +}; + +struct usdt_manager *usdt_manager_new(struct bpf_object *obj) +{ + static const char *ref_ctr_sysfs_path = "/sys/bus/event_source/devices/uprobe/format/ref_ctr_offset"; + struct usdt_manager *man; + struct bpf_map *specs_map, *ip_to_spec_id_map; + + specs_map = bpf_object__find_map_by_name(obj, "__bpf_usdt_specs"); + ip_to_spec_id_map = bpf_object__find_map_by_name(obj, "__bpf_usdt_ip_to_spec_id"); + if (!specs_map || !ip_to_spec_id_map) { + pr_warn("usdt: failed to find USDT support BPF maps, did you forget to include bpf/usdt.bpf.h?\n"); + return ERR_PTR(-ESRCH); + } + + man = calloc(1, sizeof(*man)); + if (!man) + return ERR_PTR(-ENOMEM); + + man->specs_map = specs_map; + man->ip_to_spec_id_map = ip_to_spec_id_map; + + /* Detect if BPF cookie is supported for kprobes. + * We don't need IP-to-ID mapping if we can use BPF cookies. + * Added in: 7adfc6c9b315 ("bpf: Add bpf_get_attach_cookie() BPF helper to access bpf_cookie value") + */ + man->has_bpf_cookie = kernel_supports(obj, FEAT_BPF_COOKIE); + + /* Detect kernel support for automatic refcounting of USDT semaphore. + * If this is not supported, USDTs with semaphores will not be supported. + * Added in: a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe") + */ + man->has_sema_refcnt = access(ref_ctr_sysfs_path, F_OK) == 0; + + return man; +} + +void usdt_manager_free(struct usdt_manager *man) +{ + if (IS_ERR_OR_NULL(man)) + return; + + free(man->free_spec_ids); + free(man); +} + +static int sanity_check_usdt_elf(Elf *elf, const char *path) +{ + GElf_Ehdr ehdr; + int endianness; + + if (elf_kind(elf) != ELF_K_ELF) { + pr_warn("usdt: unrecognized ELF kind %d for '%s'\n", elf_kind(elf), path); + return -EBADF; + } + + switch (gelf_getclass(elf)) { + case ELFCLASS64: + if (sizeof(void *) != 8) { + pr_warn("usdt: attaching to 64-bit ELF binary '%s' is not supported\n", path); + return -EBADF; + } + break; + case ELFCLASS32: + if (sizeof(void *) != 4) { + pr_warn("usdt: attaching to 32-bit ELF binary '%s' is not supported\n", path); + return -EBADF; + } + break; + default: + pr_warn("usdt: unsupported ELF class for '%s'\n", path); + return -EBADF; + } + + if (!gelf_getehdr(elf, &ehdr)) + return -EINVAL; + + if (ehdr.e_type != ET_EXEC && ehdr.e_type != ET_DYN) { + pr_warn("usdt: unsupported type of ELF binary '%s' (%d), only ET_EXEC and ET_DYN are supported\n", + path, ehdr.e_type); + return -EBADF; + } + +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + endianness = ELFDATA2LSB; +#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ + endianness = ELFDATA2MSB; +#else +# error "Unrecognized __BYTE_ORDER__" +#endif + if (endianness != ehdr.e_ident[EI_DATA]) { + pr_warn("usdt: ELF endianness mismatch for '%s'\n", path); + return -EBADF; + } + + return 0; +} + +static int find_elf_sec_by_name(Elf *elf, const char *sec_name, GElf_Shdr *shdr, Elf_Scn **scn) +{ + Elf_Scn *sec = NULL; + size_t shstrndx; + + if (elf_getshdrstrndx(elf, &shstrndx)) + return -EINVAL; + + /* check if ELF is corrupted and avoid calling elf_strptr if yes */ + if (!elf_rawdata(elf_getscn(elf, shstrndx), NULL)) + return -EINVAL; + + while ((sec = elf_nextscn(elf, sec)) != NULL) { + char *name; + + if (!gelf_getshdr(sec, shdr)) + return -EINVAL; + + name = elf_strptr(elf, shstrndx, shdr->sh_name); + if (name && strcmp(sec_name, name) == 0) { + *scn = sec; + return 0; + } + } + + return -ENOENT; +} + +struct elf_seg { + long start; + long end; + long offset; + bool is_exec; +}; + +static int cmp_elf_segs(const void *_a, const void *_b) +{ + const struct elf_seg *a = _a; + const struct elf_seg *b = _b; + + return a->start < b->start ? -1 : 1; +} + +static int parse_elf_segs(Elf *elf, const char *path, struct elf_seg **segs, size_t *seg_cnt) +{ + GElf_Phdr phdr; + size_t n; + int i, err; + struct elf_seg *seg; + void *tmp; + + *seg_cnt = 0; + + if (elf_getphdrnum(elf, &n)) { + err = -errno; + return err; + } + + for (i = 0; i < n; i++) { + if (!gelf_getphdr(elf, i, &phdr)) { + err = -errno; + return err; + } + + pr_debug("usdt: discovered PHDR #%d in '%s': vaddr 0x%lx memsz 0x%lx offset 0x%lx type 0x%lx flags 0x%lx\n", + i, path, (long)phdr.p_vaddr, (long)phdr.p_memsz, (long)phdr.p_offset, + (long)phdr.p_type, (long)phdr.p_flags); + if (phdr.p_type != PT_LOAD) + continue; + + tmp = libbpf_reallocarray(*segs, *seg_cnt + 1, sizeof(**segs)); + if (!tmp) + return -ENOMEM; + + *segs = tmp; + seg = *segs + *seg_cnt; + (*seg_cnt)++; + + seg->start = phdr.p_vaddr; + seg->end = phdr.p_vaddr + phdr.p_memsz; + seg->offset = phdr.p_offset; + seg->is_exec = phdr.p_flags & PF_X; + } + + if (*seg_cnt == 0) { + pr_warn("usdt: failed to find PT_LOAD program headers in '%s'\n", path); + return -ESRCH; + } + + qsort(*segs, *seg_cnt, sizeof(**segs), cmp_elf_segs); + return 0; +} + +static int parse_lib_segs(int pid, const char *lib_path, struct elf_seg **segs, size_t *seg_cnt) +{ + char path[PATH_MAX], line[PATH_MAX], mode[16]; + size_t seg_start, seg_end, seg_off; + struct elf_seg *seg; + int tmp_pid, i, err; + FILE *f; + + *seg_cnt = 0; + + /* Handle containerized binaries only accessible from + * /proc/<pid>/root/<path>. They will be reported as just /<path> in + * /proc/<pid>/maps. + */ + if (sscanf(lib_path, "/proc/%d/root%s", &tmp_pid, path) == 2 && pid == tmp_pid) + goto proceed; + + if (!realpath(lib_path, path)) { + pr_warn("usdt: failed to get absolute path of '%s' (err %d), using path as is...\n", + lib_path, -errno); + libbpf_strlcpy(path, lib_path, sizeof(path)); + } + +proceed: + sprintf(line, "/proc/%d/maps", pid); + f = fopen(line, "r"); + if (!f) { + err = -errno; + pr_warn("usdt: failed to open '%s' to get base addr of '%s': %d\n", + line, lib_path, err); + return err; + } + + /* We need to handle lines with no path at the end: + * + * 7f5c6f5d1000-7f5c6f5d3000 rw-p 001c7000 08:04 21238613 /usr/lib64/libc-2.17.so + * 7f5c6f5d3000-7f5c6f5d8000 rw-p 00000000 00:00 0 + * 7f5c6f5d8000-7f5c6f5d9000 r-xp 00000000 103:01 362990598 /data/users/andriin/linux/tools/bpf/usdt/libhello_usdt.so + */ + while (fscanf(f, "%zx-%zx %s %zx %*s %*d%[^\n]\n", + &seg_start, &seg_end, mode, &seg_off, line) == 5) { + void *tmp; + + /* to handle no path case (see above) we need to capture line + * without skipping any whitespaces. So we need to strip + * leading whitespaces manually here + */ + i = 0; + while (isblank(line[i])) + i++; + if (strcmp(line + i, path) != 0) + continue; + + pr_debug("usdt: discovered segment for lib '%s': addrs %zx-%zx mode %s offset %zx\n", + path, seg_start, seg_end, mode, seg_off); + + /* ignore non-executable sections for shared libs */ + if (mode[2] != 'x') + continue; + + tmp = libbpf_reallocarray(*segs, *seg_cnt + 1, sizeof(**segs)); + if (!tmp) { + err = -ENOMEM; + goto err_out; + } + + *segs = tmp; + seg = *segs + *seg_cnt; + *seg_cnt += 1; + + seg->start = seg_start; + seg->end = seg_end; + seg->offset = seg_off; + seg->is_exec = true; + } + + if (*seg_cnt == 0) { + pr_warn("usdt: failed to find '%s' (resolved to '%s') within PID %d memory mappings\n", + lib_path, path, pid); + err = -ESRCH; + goto err_out; + } + + qsort(*segs, *seg_cnt, sizeof(**segs), cmp_elf_segs); + err = 0; +err_out: + fclose(f); + return err; +} + +static struct elf_seg *find_elf_seg(struct elf_seg *segs, size_t seg_cnt, long addr, bool relative) +{ + struct elf_seg *seg; + int i; + + if (relative) { + /* for shared libraries, address is relative offset and thus + * should be fall within logical offset-based range of + * [offset_start, offset_end) + */ + for (i = 0, seg = segs; i < seg_cnt; i++, seg++) { + if (seg->offset <= addr && addr < seg->offset + (seg->end - seg->start)) + return seg; + } + } else { + /* for binaries, address is absolute and thus should be within + * absolute address range of [seg_start, seg_end) + */ + for (i = 0, seg = segs; i < seg_cnt; i++, seg++) { + if (seg->start <= addr && addr < seg->end) + return seg; + } + } + + return NULL; +} + +static int parse_usdt_note(Elf *elf, const char *path, long base_addr, + GElf_Nhdr *nhdr, const char *data, size_t name_off, size_t desc_off, + struct usdt_note *usdt_note); + +static int parse_usdt_spec(struct usdt_spec *spec, const struct usdt_note *note, long usdt_cookie); + +static int collect_usdt_targets(struct usdt_manager *man, Elf *elf, const char *path, pid_t pid, + const char *usdt_provider, const char *usdt_name, long usdt_cookie, + struct usdt_target **out_targets, size_t *out_target_cnt) +{ + size_t off, name_off, desc_off, seg_cnt = 0, lib_seg_cnt = 0, target_cnt = 0; + struct elf_seg *segs = NULL, *lib_segs = NULL; + struct usdt_target *targets = NULL, *target; + long base_addr = 0; + Elf_Scn *notes_scn, *base_scn; + GElf_Shdr base_shdr, notes_shdr; + GElf_Ehdr ehdr; + GElf_Nhdr nhdr; + Elf_Data *data; + int err; + + *out_targets = NULL; + *out_target_cnt = 0; + + err = find_elf_sec_by_name(elf, USDT_NOTE_SEC, ¬es_shdr, ¬es_scn); + if (err) { + pr_warn("usdt: no USDT notes section (%s) found in '%s'\n", USDT_NOTE_SEC, path); + return err; + } + + if (notes_shdr.sh_type != SHT_NOTE || !gelf_getehdr(elf, &ehdr)) { + pr_warn("usdt: invalid USDT notes section (%s) in '%s'\n", USDT_NOTE_SEC, path); + return -EINVAL; + } + + err = parse_elf_segs(elf, path, &segs, &seg_cnt); + if (err) { + pr_warn("usdt: failed to process ELF program segments for '%s': %d\n", path, err); + goto err_out; + } + + /* .stapsdt.base ELF section is optional, but is used for prelink + * offset compensation (see a big comment further below) + */ + if (find_elf_sec_by_name(elf, USDT_BASE_SEC, &base_shdr, &base_scn) == 0) + base_addr = base_shdr.sh_addr; + + data = elf_getdata(notes_scn, 0); + off = 0; + while ((off = gelf_getnote(data, off, &nhdr, &name_off, &desc_off)) > 0) { + long usdt_abs_ip, usdt_rel_ip, usdt_sema_off = 0; + struct usdt_note note; + struct elf_seg *seg = NULL; + void *tmp; + + err = parse_usdt_note(elf, path, base_addr, &nhdr, + data->d_buf, name_off, desc_off, ¬e); + if (err) + goto err_out; + + if (strcmp(note.provider, usdt_provider) != 0 || strcmp(note.name, usdt_name) != 0) + continue; + + /* We need to compensate "prelink effect". See [0] for details, + * relevant parts quoted here: + * + * Each SDT probe also expands into a non-allocated ELF note. You can + * find this by looking at SHT_NOTE sections and decoding the format; + * see below for details. Because the note is non-allocated, it means + * there is no runtime cost, and also preserved in both stripped files + * and .debug files. + * + * However, this means that prelink won't adjust the note's contents + * for address offsets. Instead, this is done via the .stapsdt.base + * section. This is a special section that is added to the text. We + * will only ever have one of these sections in a final link and it + * will only ever be one byte long. Nothing about this section itself + * matters, we just use it as a marker to detect prelink address + * adjustments. + * + * Each probe note records the link-time address of the .stapsdt.base + * section alongside the probe PC address. The decoder compares the + * base address stored in the note with the .stapsdt.base section's + * sh_addr. Initially these are the same, but the section header will + * be adjusted by prelink. So the decoder applies the difference to + * the probe PC address to get the correct prelinked PC address; the + * same adjustment is applied to the semaphore address, if any. + * + * [0] https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation + */ + usdt_rel_ip = usdt_abs_ip = note.loc_addr; + if (base_addr) { + usdt_abs_ip += base_addr - note.base_addr; + usdt_rel_ip += base_addr - note.base_addr; + } + + if (ehdr.e_type == ET_EXEC) { + /* When attaching uprobes (which what USDTs basically + * are) kernel expects a relative IP to be specified, + * so if we are attaching to an executable ELF binary + * (i.e., not a shared library), we need to calculate + * proper relative IP based on ELF's load address + */ + seg = find_elf_seg(segs, seg_cnt, usdt_abs_ip, false /* relative */); + if (!seg) { + err = -ESRCH; + pr_warn("usdt: failed to find ELF program segment for '%s:%s' in '%s' at IP 0x%lx\n", + usdt_provider, usdt_name, path, usdt_abs_ip); + goto err_out; + } + if (!seg->is_exec) { + err = -ESRCH; + pr_warn("usdt: matched ELF binary '%s' segment [0x%lx, 0x%lx) for '%s:%s' at IP 0x%lx is not executable\n", + path, seg->start, seg->end, usdt_provider, usdt_name, + usdt_abs_ip); + goto err_out; + } + + usdt_rel_ip = usdt_abs_ip - (seg->start - seg->offset); + } else if (!man->has_bpf_cookie) { /* ehdr.e_type == ET_DYN */ + /* If we don't have BPF cookie support but need to + * attach to a shared library, we'll need to know and + * record absolute addresses of attach points due to + * the need to lookup USDT spec by absolute IP of + * triggered uprobe. Doing this resolution is only + * possible when we have a specific PID of the process + * that's using specified shared library. BPF cookie + * removes the absolute address limitation as we don't + * need to do this lookup (we just use BPF cookie as + * an index of USDT spec), so for newer kernels with + * BPF cookie support libbpf supports USDT attachment + * to shared libraries with no PID filter. + */ + if (pid < 0) { + pr_warn("usdt: attaching to shared libraries without specific PID is not supported on current kernel\n"); + err = -ENOTSUP; + goto err_out; + } + + /* lib_segs are lazily initialized only if necessary */ + if (lib_seg_cnt == 0) { + err = parse_lib_segs(pid, path, &lib_segs, &lib_seg_cnt); + if (err) { + pr_warn("usdt: failed to get memory segments in PID %d for shared library '%s': %d\n", + pid, path, err); + goto err_out; + } + } + + seg = find_elf_seg(lib_segs, lib_seg_cnt, usdt_rel_ip, true /* relative */); + if (!seg) { + err = -ESRCH; + pr_warn("usdt: failed to find shared lib memory segment for '%s:%s' in '%s' at relative IP 0x%lx\n", + usdt_provider, usdt_name, path, usdt_rel_ip); + goto err_out; + } + + usdt_abs_ip = seg->start + (usdt_rel_ip - seg->offset); + } + + pr_debug("usdt: probe for '%s:%s' in %s '%s': addr 0x%lx base 0x%lx (resolved abs_ip 0x%lx rel_ip 0x%lx) args '%s' in segment [0x%lx, 0x%lx) at offset 0x%lx\n", + usdt_provider, usdt_name, ehdr.e_type == ET_EXEC ? "exec" : "lib ", path, + note.loc_addr, note.base_addr, usdt_abs_ip, usdt_rel_ip, note.args, + seg ? seg->start : 0, seg ? seg->end : 0, seg ? seg->offset : 0); + + /* Adjust semaphore address to be a relative offset */ + if (note.sema_addr) { + if (!man->has_sema_refcnt) { + pr_warn("usdt: kernel doesn't support USDT semaphore refcounting for '%s:%s' in '%s'\n", + usdt_provider, usdt_name, path); + err = -ENOTSUP; + goto err_out; + } + + seg = find_elf_seg(segs, seg_cnt, note.sema_addr, false /* relative */); + if (!seg) { + err = -ESRCH; + pr_warn("usdt: failed to find ELF loadable segment with semaphore of '%s:%s' in '%s' at 0x%lx\n", + usdt_provider, usdt_name, path, note.sema_addr); + goto err_out; + } + if (seg->is_exec) { + err = -ESRCH; + pr_warn("usdt: matched ELF binary '%s' segment [0x%lx, 0x%lx] for semaphore of '%s:%s' at 0x%lx is executable\n", + path, seg->start, seg->end, usdt_provider, usdt_name, + note.sema_addr); + goto err_out; + } + + usdt_sema_off = note.sema_addr - (seg->start - seg->offset); + + pr_debug("usdt: sema for '%s:%s' in %s '%s': addr 0x%lx base 0x%lx (resolved 0x%lx) in segment [0x%lx, 0x%lx] at offset 0x%lx\n", + usdt_provider, usdt_name, ehdr.e_type == ET_EXEC ? "exec" : "lib ", + path, note.sema_addr, note.base_addr, usdt_sema_off, + seg->start, seg->end, seg->offset); + } + + /* Record adjusted addresses and offsets and parse USDT spec */ + tmp = libbpf_reallocarray(targets, target_cnt + 1, sizeof(*targets)); + if (!tmp) { + err = -ENOMEM; + goto err_out; + } + targets = tmp; + + target = &targets[target_cnt]; + memset(target, 0, sizeof(*target)); + + target->abs_ip = usdt_abs_ip; + target->rel_ip = usdt_rel_ip; + target->sema_off = usdt_sema_off; + + /* notes->args references strings from Elf itself, so they can + * be referenced safely until elf_end() call + */ + target->spec_str = note.args; + + err = parse_usdt_spec(&target->spec, ¬e, usdt_cookie); + if (err) + goto err_out; + + target_cnt++; + } + + *out_targets = targets; + *out_target_cnt = target_cnt; + err = target_cnt; + +err_out: + free(segs); + free(lib_segs); + if (err < 0) + free(targets); + return err; +} + +struct bpf_link_usdt { + struct bpf_link link; + + struct usdt_manager *usdt_man; + + size_t spec_cnt; + int *spec_ids; + + size_t uprobe_cnt; + struct { + long abs_ip; + struct bpf_link *link; + } *uprobes; +}; + +static int bpf_link_usdt_detach(struct bpf_link *link) +{ + struct bpf_link_usdt *usdt_link = container_of(link, struct bpf_link_usdt, link); + struct usdt_manager *man = usdt_link->usdt_man; + int i; + + for (i = 0; i < usdt_link->uprobe_cnt; i++) { + /* detach underlying uprobe link */ + bpf_link__destroy(usdt_link->uprobes[i].link); + /* there is no need to update specs map because it will be + * unconditionally overwritten on subsequent USDT attaches, + * but if BPF cookies are not used we need to remove entry + * from ip_to_spec_id map, otherwise we'll run into false + * conflicting IP errors + */ + if (!man->has_bpf_cookie) { + /* not much we can do about errors here */ + (void)bpf_map_delete_elem(bpf_map__fd(man->ip_to_spec_id_map), + &usdt_link->uprobes[i].abs_ip); + } + } + + /* try to return the list of previously used spec IDs to usdt_manager + * for future reuse for subsequent USDT attaches + */ + if (!man->free_spec_ids) { + /* if there were no free spec IDs yet, just transfer our IDs */ + man->free_spec_ids = usdt_link->spec_ids; + man->free_spec_cnt = usdt_link->spec_cnt; + usdt_link->spec_ids = NULL; + } else { + /* otherwise concat IDs */ + size_t new_cnt = man->free_spec_cnt + usdt_link->spec_cnt; + int *new_free_ids; + + new_free_ids = libbpf_reallocarray(man->free_spec_ids, new_cnt, + sizeof(*new_free_ids)); + /* If we couldn't resize free_spec_ids, we'll just leak + * a bunch of free IDs; this is very unlikely to happen and if + * system is so exhausted on memory, it's the least of user's + * concerns, probably. + * So just do our best here to return those IDs to usdt_manager. + */ + if (new_free_ids) { + memcpy(new_free_ids + man->free_spec_cnt, usdt_link->spec_ids, + usdt_link->spec_cnt * sizeof(*usdt_link->spec_ids)); + man->free_spec_ids = new_free_ids; + man->free_spec_cnt = new_cnt; + } + } + + return 0; +} + +static void bpf_link_usdt_dealloc(struct bpf_link *link) +{ + struct bpf_link_usdt *usdt_link = container_of(link, struct bpf_link_usdt, link); + + free(usdt_link->spec_ids); + free(usdt_link->uprobes); + free(usdt_link); +} + +static size_t specs_hash_fn(const void *key, void *ctx) +{ + const char *s = key; + + return str_hash(s); +} + +static bool specs_equal_fn(const void *key1, const void *key2, void *ctx) +{ + const char *s1 = key1; + const char *s2 = key2; + + return strcmp(s1, s2) == 0; +} + +static int allocate_spec_id(struct usdt_manager *man, struct hashmap *specs_hash, + struct bpf_link_usdt *link, struct usdt_target *target, + int *spec_id, bool *is_new) +{ + void *tmp; + int err; + + /* check if we already allocated spec ID for this spec string */ + if (hashmap__find(specs_hash, target->spec_str, &tmp)) { + *spec_id = (long)tmp; + *is_new = false; + return 0; + } + + /* otherwise it's a new ID that needs to be set up in specs map and + * returned back to usdt_manager when USDT link is detached + */ + tmp = libbpf_reallocarray(link->spec_ids, link->spec_cnt + 1, sizeof(*link->spec_ids)); + if (!tmp) + return -ENOMEM; + link->spec_ids = tmp; + + /* get next free spec ID, giving preference to free list, if not empty */ + if (man->free_spec_cnt) { + *spec_id = man->free_spec_ids[man->free_spec_cnt - 1]; + + /* cache spec ID for current spec string for future lookups */ + err = hashmap__add(specs_hash, target->spec_str, (void *)(long)*spec_id); + if (err) + return err; + + man->free_spec_cnt--; + } else { + /* don't allocate spec ID bigger than what fits in specs map */ + if (man->next_free_spec_id >= bpf_map__max_entries(man->specs_map)) + return -E2BIG; + + *spec_id = man->next_free_spec_id; + + /* cache spec ID for current spec string for future lookups */ + err = hashmap__add(specs_hash, target->spec_str, (void *)(long)*spec_id); + if (err) + return err; + + man->next_free_spec_id++; + } + + /* remember new spec ID in the link for later return back to free list on detach */ + link->spec_ids[link->spec_cnt] = *spec_id; + link->spec_cnt++; + *is_new = true; + return 0; +} + +struct bpf_link *usdt_manager_attach_usdt(struct usdt_manager *man, const struct bpf_program *prog, + pid_t pid, const char *path, + const char *usdt_provider, const char *usdt_name, + long usdt_cookie) +{ + int i, fd, err, spec_map_fd, ip_map_fd; + LIBBPF_OPTS(bpf_uprobe_opts, opts); + struct hashmap *specs_hash = NULL; + struct bpf_link_usdt *link = NULL; + struct usdt_target *targets = NULL; + size_t target_cnt; + Elf *elf; + + spec_map_fd = bpf_map__fd(man->specs_map); + ip_map_fd = bpf_map__fd(man->ip_to_spec_id_map); + + /* TODO: perform path resolution similar to uprobe's */ + fd = open(path, O_RDONLY); + if (fd < 0) { + err = -errno; + pr_warn("usdt: failed to open ELF binary '%s': %d\n", path, err); + return libbpf_err_ptr(err); + } + + elf = elf_begin(fd, ELF_C_READ_MMAP, NULL); + if (!elf) { + err = -EBADF; + pr_warn("usdt: failed to parse ELF binary '%s': %s\n", path, elf_errmsg(-1)); + goto err_out; + } + + err = sanity_check_usdt_elf(elf, path); + if (err) + goto err_out; + + /* normalize PID filter */ + if (pid < 0) + pid = -1; + else if (pid == 0) + pid = getpid(); + + /* discover USDT in given binary, optionally limiting + * activations to a given PID, if pid > 0 + */ + err = collect_usdt_targets(man, elf, path, pid, usdt_provider, usdt_name, + usdt_cookie, &targets, &target_cnt); + if (err <= 0) { + err = (err == 0) ? -ENOENT : err; + goto err_out; + } + + specs_hash = hashmap__new(specs_hash_fn, specs_equal_fn, NULL); + if (IS_ERR(specs_hash)) { + err = PTR_ERR(specs_hash); + goto err_out; + } + + link = calloc(1, sizeof(*link)); + if (!link) { + err = -ENOMEM; + goto err_out; + } + + link->usdt_man = man; + link->link.detach = &bpf_link_usdt_detach; + link->link.dealloc = &bpf_link_usdt_dealloc; + + link->uprobes = calloc(target_cnt, sizeof(*link->uprobes)); + if (!link->uprobes) { + err = -ENOMEM; + goto err_out; + } + + for (i = 0; i < target_cnt; i++) { + struct usdt_target *target = &targets[i]; + struct bpf_link *uprobe_link; + bool is_new; + int spec_id; + + /* Spec ID can be either reused or newly allocated. If it is + * newly allocated, we'll need to fill out spec map, otherwise + * entire spec should be valid and can be just used by a new + * uprobe. We reuse spec when USDT arg spec is identical. We + * also never share specs between two different USDT + * attachments ("links"), so all the reused specs already + * share USDT cookie value implicitly. + */ + err = allocate_spec_id(man, specs_hash, link, target, &spec_id, &is_new); + if (err) + goto err_out; + + if (is_new && bpf_map_update_elem(spec_map_fd, &spec_id, &target->spec, BPF_ANY)) { + err = -errno; + pr_warn("usdt: failed to set USDT spec #%d for '%s:%s' in '%s': %d\n", + spec_id, usdt_provider, usdt_name, path, err); + goto err_out; + } + if (!man->has_bpf_cookie && + bpf_map_update_elem(ip_map_fd, &target->abs_ip, &spec_id, BPF_NOEXIST)) { + err = -errno; + if (err == -EEXIST) { + pr_warn("usdt: IP collision detected for spec #%d for '%s:%s' in '%s'\n", + spec_id, usdt_provider, usdt_name, path); + } else { + pr_warn("usdt: failed to map IP 0x%lx to spec #%d for '%s:%s' in '%s': %d\n", + target->abs_ip, spec_id, usdt_provider, usdt_name, + path, err); + } + goto err_out; + } + + opts.ref_ctr_offset = target->sema_off; + opts.bpf_cookie = man->has_bpf_cookie ? spec_id : 0; + uprobe_link = bpf_program__attach_uprobe_opts(prog, pid, path, + target->rel_ip, &opts); + err = libbpf_get_error(uprobe_link); + if (err) { + pr_warn("usdt: failed to attach uprobe #%d for '%s:%s' in '%s': %d\n", + i, usdt_provider, usdt_name, path, err); + goto err_out; + } + + link->uprobes[i].link = uprobe_link; + link->uprobes[i].abs_ip = target->abs_ip; + link->uprobe_cnt++; + } + + free(targets); + hashmap__free(specs_hash); + elf_end(elf); + close(fd); + + return &link->link; + +err_out: + if (link) + bpf_link__destroy(&link->link); + free(targets); + hashmap__free(specs_hash); + if (elf) + elf_end(elf); + close(fd); + return libbpf_err_ptr(err); +} + +/* Parse out USDT ELF note from '.note.stapsdt' section. + * Logic inspired by perf's code. + */ +static int parse_usdt_note(Elf *elf, const char *path, long base_addr, + GElf_Nhdr *nhdr, const char *data, size_t name_off, size_t desc_off, + struct usdt_note *note) +{ + const char *provider, *name, *args; + long addrs[3]; + size_t len; + + /* sanity check USDT note name and type first */ + if (strncmp(data + name_off, USDT_NOTE_NAME, nhdr->n_namesz) != 0) + return -EINVAL; + if (nhdr->n_type != USDT_NOTE_TYPE) + return -EINVAL; + + /* sanity check USDT note contents ("description" in ELF terminology) */ + len = nhdr->n_descsz; + data = data + desc_off; + + /* +3 is the very minimum required to store three empty strings */ + if (len < sizeof(addrs) + 3) + return -EINVAL; + + /* get location, base, and semaphore addrs */ + memcpy(&addrs, data, sizeof(addrs)); + + /* parse string fields: provider, name, args */ + provider = data + sizeof(addrs); + + name = (const char *)memchr(provider, '\0', data + len - provider); + if (!name) /* non-zero-terminated provider */ + return -EINVAL; + name++; + if (name >= data + len || *name == '\0') /* missing or empty name */ + return -EINVAL; + + args = memchr(name, '\0', data + len - name); + if (!args) /* non-zero-terminated name */ + return -EINVAL; + ++args; + if (args >= data + len) /* missing arguments spec */ + return -EINVAL; + + note->provider = provider; + note->name = name; + if (*args == '\0' || *args == ':') + note->args = ""; + else + note->args = args; + note->loc_addr = addrs[0]; + note->base_addr = addrs[1]; + note->sema_addr = addrs[2]; + + return 0; +} + +static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg); + +static int parse_usdt_spec(struct usdt_spec *spec, const struct usdt_note *note, long usdt_cookie) +{ + const char *s; + int len; + + spec->usdt_cookie = usdt_cookie; + spec->arg_cnt = 0; + + s = note->args; + while (s[0]) { + if (spec->arg_cnt >= USDT_MAX_ARG_CNT) { + pr_warn("usdt: too many USDT arguments (> %d) for '%s:%s' with args spec '%s'\n", + USDT_MAX_ARG_CNT, note->provider, note->name, note->args); + return -E2BIG; + } + + len = parse_usdt_arg(s, spec->arg_cnt, &spec->args[spec->arg_cnt]); + if (len < 0) + return len; + + s += len; + spec->arg_cnt++; + } + + return 0; +} + +/* Architecture-specific logic for parsing USDT argument location specs */ + +#if defined(__x86_64__) || defined(__i386__) + +static int calc_pt_regs_off(const char *reg_name) +{ + static struct { + const char *names[4]; + size_t pt_regs_off; + } reg_map[] = { +#ifdef __x86_64__ +#define reg_off(reg64, reg32) offsetof(struct pt_regs, reg64) +#else +#define reg_off(reg64, reg32) offsetof(struct pt_regs, reg32) +#endif + { {"rip", "eip", "", ""}, reg_off(rip, eip) }, + { {"rax", "eax", "ax", "al"}, reg_off(rax, eax) }, + { {"rbx", "ebx", "bx", "bl"}, reg_off(rbx, ebx) }, + { {"rcx", "ecx", "cx", "cl"}, reg_off(rcx, ecx) }, + { {"rdx", "edx", "dx", "dl"}, reg_off(rdx, edx) }, + { {"rsi", "esi", "si", "sil"}, reg_off(rsi, esi) }, + { {"rdi", "edi", "di", "dil"}, reg_off(rdi, edi) }, + { {"rbp", "ebp", "bp", "bpl"}, reg_off(rbp, ebp) }, + { {"rsp", "esp", "sp", "spl"}, reg_off(rsp, esp) }, +#undef reg_off +#ifdef __x86_64__ + { {"r8", "r8d", "r8w", "r8b"}, offsetof(struct pt_regs, r8) }, + { {"r9", "r9d", "r9w", "r9b"}, offsetof(struct pt_regs, r9) }, + { {"r10", "r10d", "r10w", "r10b"}, offsetof(struct pt_regs, r10) }, + { {"r11", "r11d", "r11w", "r11b"}, offsetof(struct pt_regs, r11) }, + { {"r12", "r12d", "r12w", "r12b"}, offsetof(struct pt_regs, r12) }, + { {"r13", "r13d", "r13w", "r13b"}, offsetof(struct pt_regs, r13) }, + { {"r14", "r14d", "r14w", "r14b"}, offsetof(struct pt_regs, r14) }, + { {"r15", "r15d", "r15w", "r15b"}, offsetof(struct pt_regs, r15) }, +#endif + }; + int i, j; + + for (i = 0; i < ARRAY_SIZE(reg_map); i++) { + for (j = 0; j < ARRAY_SIZE(reg_map[i].names); j++) { + if (strcmp(reg_name, reg_map[i].names[j]) == 0) + return reg_map[i].pt_regs_off; + } + } + + pr_warn("usdt: unrecognized register '%s'\n", reg_name); + return -ENOENT; +} + +static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg) +{ + char *reg_name = NULL; + int arg_sz, len, reg_off; + long off; + + if (sscanf(arg_str, " %d @ %ld ( %%%m[^)] ) %n", &arg_sz, &off, ®_name, &len) == 3) { + /* Memory dereference case, e.g., -4@-20(%rbp) */ + arg->arg_type = USDT_ARG_REG_DEREF; + arg->val_off = off; + reg_off = calc_pt_regs_off(reg_name); + free(reg_name); + if (reg_off < 0) + return reg_off; + arg->reg_off = reg_off; + } else if (sscanf(arg_str, " %d @ %%%ms %n", &arg_sz, ®_name, &len) == 2) { + /* Register read case, e.g., -4@%eax */ + arg->arg_type = USDT_ARG_REG; + arg->val_off = 0; + + reg_off = calc_pt_regs_off(reg_name); + free(reg_name); + if (reg_off < 0) + return reg_off; + arg->reg_off = reg_off; + } else if (sscanf(arg_str, " %d @ $%ld %n", &arg_sz, &off, &len) == 2) { + /* Constant value case, e.g., 4@$71 */ + arg->arg_type = USDT_ARG_CONST; + arg->val_off = off; + arg->reg_off = 0; + } else { + pr_warn("usdt: unrecognized arg #%d spec '%s'\n", arg_num, arg_str); + return -EINVAL; + } + + arg->arg_signed = arg_sz < 0; + if (arg_sz < 0) + arg_sz = -arg_sz; + + switch (arg_sz) { + case 1: case 2: case 4: case 8: + arg->arg_bitshift = 64 - arg_sz * 8; + break; + default: + pr_warn("usdt: unsupported arg #%d (spec '%s') size: %d\n", + arg_num, arg_str, arg_sz); + return -EINVAL; + } + + return len; +} + +#elif defined(__s390x__) + +/* Do not support __s390__ for now, since user_pt_regs is broken with -m31. */ + +static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg) +{ + unsigned int reg; + int arg_sz, len; + long off; + + if (sscanf(arg_str, " %d @ %ld ( %%r%u ) %n", &arg_sz, &off, ®, &len) == 3) { + /* Memory dereference case, e.g., -2@-28(%r15) */ + arg->arg_type = USDT_ARG_REG_DEREF; + arg->val_off = off; + if (reg > 15) { + pr_warn("usdt: unrecognized register '%%r%u'\n", reg); + return -EINVAL; + } + arg->reg_off = offsetof(user_pt_regs, gprs[reg]); + } else if (sscanf(arg_str, " %d @ %%r%u %n", &arg_sz, ®, &len) == 2) { + /* Register read case, e.g., -8@%r0 */ + arg->arg_type = USDT_ARG_REG; + arg->val_off = 0; + if (reg > 15) { + pr_warn("usdt: unrecognized register '%%r%u'\n", reg); + return -EINVAL; + } + arg->reg_off = offsetof(user_pt_regs, gprs[reg]); + } else if (sscanf(arg_str, " %d @ %ld %n", &arg_sz, &off, &len) == 2) { + /* Constant value case, e.g., 4@71 */ + arg->arg_type = USDT_ARG_CONST; + arg->val_off = off; + arg->reg_off = 0; + } else { + pr_warn("usdt: unrecognized arg #%d spec '%s'\n", arg_num, arg_str); + return -EINVAL; + } + + arg->arg_signed = arg_sz < 0; + if (arg_sz < 0) + arg_sz = -arg_sz; + + switch (arg_sz) { + case 1: case 2: case 4: case 8: + arg->arg_bitshift = 64 - arg_sz * 8; + break; + default: + pr_warn("usdt: unsupported arg #%d (spec '%s') size: %d\n", + arg_num, arg_str, arg_sz); + return -EINVAL; + } + + return len; +} + +#else + +static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg) +{ + pr_warn("usdt: libbpf doesn't support USDTs on current architecture\n"); + return -ENOTSUP; +} + +#endif diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 3820608faf57..bafdc5373a13 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -168,9 +168,15 @@ $(OUTPUT)/%:%.c $(call msg,BINARY,,$@) $(Q)$(LINK.c) $^ $(LDLIBS) -o $@ -$(OUTPUT)/urandom_read: urandom_read.c +$(OUTPUT)/liburandom_read.so: urandom_read_lib1.c urandom_read_lib2.c + $(call msg,LIB,,$@) + $(Q)$(CC) $(CFLAGS) -fPIC $(LDFLAGS) $^ $(LDLIBS) --shared -o $@ + +$(OUTPUT)/urandom_read: urandom_read.c urandom_read_aux.c $(OUTPUT)/liburandom_read.so $(call msg,BINARY,,$@) - $(Q)$(CC) $(CFLAGS) $(LDFLAGS) $< $(LDLIBS) -Wl,--build-id=sha1 -o $@ + $(Q)$(CC) $(CFLAGS) $(LDFLAGS) $(filter %.c,$^) \ + liburandom_read.so $(LDLIBS) \ + -Wl,-rpath=. -Wl,--build-id=sha1 -o $@ $(OUTPUT)/bpf_testmod.ko: $(VMLINUX_BTF) $(wildcard bpf_testmod/Makefile bpf_testmod/*.[ch]) $(call msg,MOD,,$@) @@ -328,12 +334,8 @@ SKEL_BLACKLIST := btf__% test_pinning_invalid.c test_sk_assign.c LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h \ linked_vars.skel.h linked_maps.skel.h \ - test_subskeleton.skel.h test_subskeleton_lib.skel.h - -# In the subskeleton case, we want the test_subskeleton_lib.subskel.h file -# but that's created as a side-effect of the skel.h generation. -test_subskeleton.skel.h-deps := test_subskeleton_lib2.o test_subskeleton_lib.o test_subskeleton.o -test_subskeleton_lib.skel.h-deps := test_subskeleton_lib2.o test_subskeleton_lib.o + test_subskeleton.skel.h test_subskeleton_lib.skel.h \ + test_usdt.skel.h LSKELS := kfunc_call_test.c fentry_test.c fexit_test.c fexit_sleep.c \ test_ringbuf.c atomics.c trace_printk.c trace_vprintk.c \ @@ -346,6 +348,11 @@ test_static_linked.skel.h-deps := test_static_linked1.o test_static_linked2.o linked_funcs.skel.h-deps := linked_funcs1.o linked_funcs2.o linked_vars.skel.h-deps := linked_vars1.o linked_vars2.o linked_maps.skel.h-deps := linked_maps1.o linked_maps2.o +# In the subskeleton case, we want the test_subskeleton_lib.subskel.h file +# but that's created as a side-effect of the skel.h generation. +test_subskeleton.skel.h-deps := test_subskeleton_lib2.o test_subskeleton_lib.o test_subskeleton.o +test_subskeleton_lib.skel.h-deps := test_subskeleton_lib2.o test_subskeleton_lib.o +test_usdt.skel.h-deps := test_usdt.o test_usdt_multispec.o LINKED_BPF_SRCS := $(patsubst %.o,%.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps))) @@ -400,6 +407,7 @@ $(TRUNNER_BPF_OBJS): $(TRUNNER_OUTPUT)/%.o: \ $(TRUNNER_BPF_PROGS_DIR)/*.h \ $$(INCLUDE_DIR)/vmlinux.h \ $(wildcard $(BPFDIR)/bpf_*.h) \ + $(wildcard $(BPFDIR)/*.bpf.h) \ | $(TRUNNER_OUTPUT) $$(BPFOBJ) $$(call $(TRUNNER_BPF_BUILD_RULE),$$<,$$@, \ $(TRUNNER_BPF_CFLAGS)) @@ -491,6 +499,7 @@ TRUNNER_EXTRA_SOURCES := test_progs.c cgroup_helpers.c trace_helpers.c \ btf_helpers.c flow_dissector_load.h \ cap_helpers.c TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read $(OUTPUT)/bpf_testmod.ko \ + $(OUTPUT)/liburandom_read.so \ ima_setup.sh \ $(wildcard progs/btf_dump_test_case_*.c) TRUNNER_BPF_BUILD_RULE := CLANG_BPF_BUILD_RULE diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c index d48f6e533e1e..c0c6d410751d 100644 --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c @@ -11,15 +11,22 @@ static void trigger_func(void) asm volatile (""); } +/* attach point for byname uprobe */ +static void trigger_func2(void) +{ + asm volatile (""); +} + void test_attach_probe(void) { DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts); - int duration = 0; struct bpf_link *kprobe_link, *kretprobe_link; struct bpf_link *uprobe_link, *uretprobe_link; struct test_attach_probe* skel; ssize_t uprobe_offset, ref_ctr_offset; + struct bpf_link *uprobe_err_link; bool legacy; + char *mem; /* Check if new-style kprobe/uprobe API is supported. * Kernels that support new FD-based kprobe and uprobe BPF attachment @@ -43,9 +50,9 @@ void test_attach_probe(void) return; skel = test_attach_probe__open_and_load(); - if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) + if (!ASSERT_OK_PTR(skel, "skel_open")) return; - if (CHECK(!skel->bss, "check_bss", ".bss wasn't mmap()-ed\n")) + if (!ASSERT_OK_PTR(skel->bss, "check_bss")) goto cleanup; kprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kprobe, @@ -90,25 +97,73 @@ void test_attach_probe(void) goto cleanup; skel->links.handle_uretprobe = uretprobe_link; - /* trigger & validate kprobe && kretprobe */ - usleep(1); + /* verify auto-attach fails for old-style uprobe definition */ + uprobe_err_link = bpf_program__attach(skel->progs.handle_uprobe_byname); + if (!ASSERT_EQ(libbpf_get_error(uprobe_err_link), -EOPNOTSUPP, + "auto-attach should fail for old-style name")) + goto cleanup; + + uprobe_opts.func_name = "trigger_func2"; + uprobe_opts.retprobe = false; + uprobe_opts.ref_ctr_offset = 0; + skel->links.handle_uprobe_byname = + bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname, + 0 /* this pid */, + "/proc/self/exe", + 0, &uprobe_opts); + if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname, "attach_uprobe_byname")) + goto cleanup; + + /* verify auto-attach works */ + skel->links.handle_uretprobe_byname = + bpf_program__attach(skel->progs.handle_uretprobe_byname); + if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname, "attach_uretprobe_byname")) + goto cleanup; - if (CHECK(skel->bss->kprobe_res != 1, "check_kprobe_res", - "wrong kprobe res: %d\n", skel->bss->kprobe_res)) + /* test attach by name for a library function, using the library + * as the binary argument. libc.so.6 will be resolved via dlopen()/dlinfo(). + */ + uprobe_opts.func_name = "malloc"; + uprobe_opts.retprobe = false; + skel->links.handle_uprobe_byname2 = + bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname2, + 0 /* this pid */, + "libc.so.6", + 0, &uprobe_opts); + if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname2, "attach_uprobe_byname2")) goto cleanup; - if (CHECK(skel->bss->kretprobe_res != 2, "check_kretprobe_res", - "wrong kretprobe res: %d\n", skel->bss->kretprobe_res)) + + uprobe_opts.func_name = "free"; + uprobe_opts.retprobe = true; + skel->links.handle_uretprobe_byname2 = + bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_byname2, + -1 /* any pid */, + "libc.so.6", + 0, &uprobe_opts); + if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname2, "attach_uretprobe_byname2")) goto cleanup; + /* trigger & validate kprobe && kretprobe */ + usleep(1); + + /* trigger & validate shared library u[ret]probes attached by name */ + mem = malloc(1); + free(mem); + /* trigger & validate uprobe & uretprobe */ trigger_func(); - if (CHECK(skel->bss->uprobe_res != 3, "check_uprobe_res", - "wrong uprobe res: %d\n", skel->bss->uprobe_res)) - goto cleanup; - if (CHECK(skel->bss->uretprobe_res != 4, "check_uretprobe_res", - "wrong uretprobe res: %d\n", skel->bss->uretprobe_res)) - goto cleanup; + /* trigger & validate uprobe attached by name */ + trigger_func2(); + + ASSERT_EQ(skel->bss->kprobe_res, 1, "check_kprobe_res"); + ASSERT_EQ(skel->bss->kretprobe_res, 2, "check_kretprobe_res"); + ASSERT_EQ(skel->bss->uprobe_res, 3, "check_uprobe_res"); + ASSERT_EQ(skel->bss->uretprobe_res, 4, "check_uretprobe_res"); + ASSERT_EQ(skel->bss->uprobe_byname_res, 5, "check_uprobe_byname_res"); + ASSERT_EQ(skel->bss->uretprobe_byname_res, 6, "check_uretprobe_byname_res"); + ASSERT_EQ(skel->bss->uprobe_byname2_res, 7, "check_uprobe_byname2_res"); + ASSERT_EQ(skel->bss->uretprobe_byname2_res, 8, "check_uretprobe_byname2_res"); cleanup: test_attach_probe__destroy(skel); diff --git a/tools/testing/selftests/bpf/prog_tests/for_each.c b/tools/testing/selftests/bpf/prog_tests/for_each.c index 044df13ee069..754e80937e5d 100644 --- a/tools/testing/selftests/bpf/prog_tests/for_each.c +++ b/tools/testing/selftests/bpf/prog_tests/for_each.c @@ -4,6 +4,7 @@ #include <network_helpers.h> #include "for_each_hash_map_elem.skel.h" #include "for_each_array_map_elem.skel.h" +#include "for_each_map_elem_write_key.skel.h" static unsigned int duration; @@ -129,10 +130,21 @@ out: for_each_array_map_elem__destroy(skel); } +static void test_write_map_key(void) +{ + struct for_each_map_elem_write_key *skel; + + skel = for_each_map_elem_write_key__open_and_load(); + if (!ASSERT_ERR_PTR(skel, "for_each_map_elem_write_key__open_and_load")) + for_each_map_elem_write_key__destroy(skel); +} + void test_for_each(void) { if (test__start_subtest("hash_map")) test_hash_map(); if (test__start_subtest("array_map")) test_array_map(); + if (test__start_subtest("write_map_key")) + test_write_map_key(); } diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c b/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c index f6933b06daf8..1d7a2f1e0731 100644 --- a/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c +++ b/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c @@ -138,12 +138,16 @@ cleanup: test_ksyms_weak_lskel__destroy(skel); } -static void test_write_check(void) +static void test_write_check(bool test_handler1) { struct test_ksyms_btf_write_check *skel; - skel = test_ksyms_btf_write_check__open_and_load(); - ASSERT_ERR_PTR(skel, "unexpected load of a prog writing to ksym memory\n"); + skel = test_ksyms_btf_write_check__open(); + if (!ASSERT_OK_PTR(skel, "test_ksyms_btf_write_check__open")) + return; + bpf_program__set_autoload(test_handler1 ? skel->progs.handler2 : skel->progs.handler1, false); + ASSERT_ERR(test_ksyms_btf_write_check__load(skel), + "unexpected load of a prog writing to ksym memory\n"); test_ksyms_btf_write_check__destroy(skel); } @@ -179,6 +183,9 @@ void test_ksyms_btf(void) if (test__start_subtest("weak_ksyms_lskel")) test_weak_syms_lskel(); - if (test__start_subtest("write_check")) - test_write_check(); + if (test__start_subtest("write_check1")) + test_write_check(true); + + if (test__start_subtest("write_check2")) + test_write_check(false); } diff --git a/tools/testing/selftests/bpf/prog_tests/netcnt.c b/tools/testing/selftests/bpf/prog_tests/netcnt.c index 954964f0ac3d..d3915c58d0e1 100644 --- a/tools/testing/selftests/bpf/prog_tests/netcnt.c +++ b/tools/testing/selftests/bpf/prog_tests/netcnt.c @@ -25,7 +25,7 @@ void serial_test_netcnt(void) if (!ASSERT_OK_PTR(skel, "netcnt_prog__open_and_load")) return; - nproc = get_nprocs_conf(); + nproc = bpf_num_possible_cpus(); percpu_netcnt = malloc(sizeof(*percpu_netcnt) * nproc); if (!ASSERT_OK_PTR(percpu_netcnt, "malloc(percpu_netcnt)")) goto err; diff --git a/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c b/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c index 509e21d5cb9d..b90ee47d3111 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c +++ b/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c @@ -81,6 +81,7 @@ void test_test_global_funcs(void) { "test_global_func14.o", "reference type('FWD S') size cannot be determined" }, { "test_global_func15.o", "At program exit the register R0 has value" }, { "test_global_func16.o", "invalid indirect read from stack" }, + { "test_global_func17.o", "Caller passes invalid args into func#1" }, }; libbpf_print_fn_t old_print_fn = NULL; int err, i, duration = 0; diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c b/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c new file mode 100644 index 000000000000..d6003dc8cc99 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022, Oracle and/or its affiliates. */ + +#include <test_progs.h> +#include "test_uprobe_autoattach.skel.h" + +/* uprobe attach point */ +static noinline int autoattach_trigger_func(int arg) +{ + asm volatile (""); + return arg + 1; +} + +void test_uprobe_autoattach(void) +{ + struct test_uprobe_autoattach *skel; + int trigger_val = 100, trigger_ret; + size_t malloc_sz = 1; + char *mem; + + skel = test_uprobe_autoattach__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + if (!ASSERT_OK(test_uprobe_autoattach__attach(skel), "skel_attach")) + goto cleanup; + + skel->bss->test_pid = getpid(); + + /* trigger & validate uprobe & uretprobe */ + trigger_ret = autoattach_trigger_func(trigger_val); + + skel->bss->test_pid = getpid(); + + /* trigger & validate shared library u[ret]probes attached by name */ + mem = malloc(malloc_sz); + free(mem); + + ASSERT_EQ(skel->bss->uprobe_byname_parm1, trigger_val, "check_uprobe_byname_parm1"); + ASSERT_EQ(skel->bss->uprobe_byname_ran, 1, "check_uprobe_byname_ran"); + ASSERT_EQ(skel->bss->uretprobe_byname_rc, trigger_ret, "check_uretprobe_byname_rc"); + ASSERT_EQ(skel->bss->uretprobe_byname_ran, 2, "check_uretprobe_byname_ran"); + ASSERT_EQ(skel->bss->uprobe_byname2_parm1, malloc_sz, "check_uprobe_byname2_parm1"); + ASSERT_EQ(skel->bss->uprobe_byname2_ran, 3, "check_uprobe_byname2_ran"); + ASSERT_EQ(skel->bss->uretprobe_byname2_rc, mem, "check_uretprobe_byname2_rc"); + ASSERT_EQ(skel->bss->uretprobe_byname2_ran, 4, "check_uretprobe_byname2_ran"); +cleanup: + test_uprobe_autoattach__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/prog_tests/usdt.c b/tools/testing/selftests/bpf/prog_tests/usdt.c new file mode 100644 index 000000000000..a71f51bdc08d --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/usdt.c @@ -0,0 +1,421 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ +#include <test_progs.h> + +#define _SDT_HAS_SEMAPHORES 1 +#include "../sdt.h" + +#include "test_usdt.skel.h" +#include "test_urandom_usdt.skel.h" + +int lets_test_this(int); + +static volatile int idx = 2; +static volatile __u64 bla = 0xFEDCBA9876543210ULL; +static volatile short nums[] = {-1, -2, -3, }; + +static volatile struct { + int x; + signed char y; +} t1 = { 1, -127 }; + +#define SEC(name) __attribute__((section(name), used)) + +unsigned short test_usdt0_semaphore SEC(".probes"); +unsigned short test_usdt3_semaphore SEC(".probes"); +unsigned short test_usdt12_semaphore SEC(".probes"); + +static void __always_inline trigger_func(int x) { + long y = 42; + + if (test_usdt0_semaphore) + STAP_PROBE(test, usdt0); + if (test_usdt3_semaphore) + STAP_PROBE3(test, usdt3, x, y, &bla); + if (test_usdt12_semaphore) { + STAP_PROBE12(test, usdt12, + x, x + 1, y, x + y, 5, + y / 7, bla, &bla, -9, nums[x], + nums[idx], t1.y); + } +} + +static void subtest_basic_usdt(void) +{ + LIBBPF_OPTS(bpf_usdt_opts, opts); + struct test_usdt *skel; + struct test_usdt__bss *bss; + int err; + + skel = test_usdt__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + bss = skel->bss; + bss->my_pid = getpid(); + + err = test_usdt__attach(skel); + if (!ASSERT_OK(err, "skel_attach")) + goto cleanup; + + /* usdt0 won't be auto-attached */ + opts.usdt_cookie = 0xcafedeadbeeffeed; + skel->links.usdt0 = bpf_program__attach_usdt(skel->progs.usdt0, + 0 /*self*/, "/proc/self/exe", + "test", "usdt0", &opts); + if (!ASSERT_OK_PTR(skel->links.usdt0, "usdt0_link")) + goto cleanup; + + trigger_func(1); + + ASSERT_EQ(bss->usdt0_called, 1, "usdt0_called"); + ASSERT_EQ(bss->usdt3_called, 1, "usdt3_called"); + ASSERT_EQ(bss->usdt12_called, 1, "usdt12_called"); + + ASSERT_EQ(bss->usdt0_cookie, 0xcafedeadbeeffeed, "usdt0_cookie"); + ASSERT_EQ(bss->usdt0_arg_cnt, 0, "usdt0_arg_cnt"); + ASSERT_EQ(bss->usdt0_arg_ret, -ENOENT, "usdt0_arg_ret"); + + /* auto-attached usdt3 gets default zero cookie value */ + ASSERT_EQ(bss->usdt3_cookie, 0, "usdt3_cookie"); + ASSERT_EQ(bss->usdt3_arg_cnt, 3, "usdt3_arg_cnt"); + + ASSERT_EQ(bss->usdt3_arg_rets[0], 0, "usdt3_arg1_ret"); + ASSERT_EQ(bss->usdt3_arg_rets[1], 0, "usdt3_arg2_ret"); + ASSERT_EQ(bss->usdt3_arg_rets[2], 0, "usdt3_arg3_ret"); + ASSERT_EQ(bss->usdt3_args[0], 1, "usdt3_arg1"); + ASSERT_EQ(bss->usdt3_args[1], 42, "usdt3_arg2"); + ASSERT_EQ(bss->usdt3_args[2], (uintptr_t)&bla, "usdt3_arg3"); + + /* auto-attached usdt12 gets default zero cookie value */ + ASSERT_EQ(bss->usdt12_cookie, 0, "usdt12_cookie"); + ASSERT_EQ(bss->usdt12_arg_cnt, 12, "usdt12_arg_cnt"); + + ASSERT_EQ(bss->usdt12_args[0], 1, "usdt12_arg1"); + ASSERT_EQ(bss->usdt12_args[1], 1 + 1, "usdt12_arg2"); + ASSERT_EQ(bss->usdt12_args[2], 42, "usdt12_arg3"); + ASSERT_EQ(bss->usdt12_args[3], 42 + 1, "usdt12_arg4"); + ASSERT_EQ(bss->usdt12_args[4], 5, "usdt12_arg5"); + ASSERT_EQ(bss->usdt12_args[5], 42 / 7, "usdt12_arg6"); + ASSERT_EQ(bss->usdt12_args[6], bla, "usdt12_arg7"); + ASSERT_EQ(bss->usdt12_args[7], (uintptr_t)&bla, "usdt12_arg8"); + ASSERT_EQ(bss->usdt12_args[8], -9, "usdt12_arg9"); + ASSERT_EQ(bss->usdt12_args[9], nums[1], "usdt12_arg10"); + ASSERT_EQ(bss->usdt12_args[10], nums[idx], "usdt12_arg11"); + ASSERT_EQ(bss->usdt12_args[11], t1.y, "usdt12_arg12"); + + /* trigger_func() is marked __always_inline, so USDT invocations will be + * inlined in two different places, meaning that each USDT will have + * at least 2 different places to be attached to. This verifies that + * bpf_program__attach_usdt() handles this properly and attaches to + * all possible places of USDT invocation. + */ + trigger_func(2); + + ASSERT_EQ(bss->usdt0_called, 2, "usdt0_called"); + ASSERT_EQ(bss->usdt3_called, 2, "usdt3_called"); + ASSERT_EQ(bss->usdt12_called, 2, "usdt12_called"); + + /* only check values that depend on trigger_func()'s input value */ + ASSERT_EQ(bss->usdt3_args[0], 2, "usdt3_arg1"); + + ASSERT_EQ(bss->usdt12_args[0], 2, "usdt12_arg1"); + ASSERT_EQ(bss->usdt12_args[1], 2 + 1, "usdt12_arg2"); + ASSERT_EQ(bss->usdt12_args[3], 42 + 2, "usdt12_arg4"); + ASSERT_EQ(bss->usdt12_args[9], nums[2], "usdt12_arg10"); + + /* detach and re-attach usdt3 */ + bpf_link__destroy(skel->links.usdt3); + + opts.usdt_cookie = 0xBADC00C51E; + skel->links.usdt3 = bpf_program__attach_usdt(skel->progs.usdt3, -1 /* any pid */, + "/proc/self/exe", "test", "usdt3", &opts); + if (!ASSERT_OK_PTR(skel->links.usdt3, "usdt3_reattach")) + goto cleanup; + + trigger_func(3); + + ASSERT_EQ(bss->usdt3_called, 3, "usdt3_called"); + /* this time usdt3 has custom cookie */ + ASSERT_EQ(bss->usdt3_cookie, 0xBADC00C51E, "usdt3_cookie"); + ASSERT_EQ(bss->usdt3_arg_cnt, 3, "usdt3_arg_cnt"); + + ASSERT_EQ(bss->usdt3_arg_rets[0], 0, "usdt3_arg1_ret"); + ASSERT_EQ(bss->usdt3_arg_rets[1], 0, "usdt3_arg2_ret"); + ASSERT_EQ(bss->usdt3_arg_rets[2], 0, "usdt3_arg3_ret"); + ASSERT_EQ(bss->usdt3_args[0], 3, "usdt3_arg1"); + ASSERT_EQ(bss->usdt3_args[1], 42, "usdt3_arg2"); + ASSERT_EQ(bss->usdt3_args[2], (uintptr_t)&bla, "usdt3_arg3"); + +cleanup: + test_usdt__destroy(skel); +} + +unsigned short test_usdt_100_semaphore SEC(".probes"); +unsigned short test_usdt_300_semaphore SEC(".probes"); +unsigned short test_usdt_400_semaphore SEC(".probes"); + +#define R10(F, X) F(X+0); F(X+1);F(X+2); F(X+3); F(X+4); \ + F(X+5); F(X+6); F(X+7); F(X+8); F(X+9); +#define R100(F, X) R10(F,X+ 0);R10(F,X+10);R10(F,X+20);R10(F,X+30);R10(F,X+40); \ + R10(F,X+50);R10(F,X+60);R10(F,X+70);R10(F,X+80);R10(F,X+90); + +/* carefully control that we get exactly 100 inlines by preventing inlining */ +static void __always_inline f100(int x) +{ + STAP_PROBE1(test, usdt_100, x); +} + +__weak void trigger_100_usdts(void) +{ + R100(f100, 0); +} + +/* we shouldn't be able to attach to test:usdt2_300 USDT as we don't have as + * many slots for specs. It's important that each STAP_PROBE2() invocation + * (after untolling) gets different arg spec due to compiler inlining i as + * a constant + */ +static void __always_inline f300(int x) +{ + STAP_PROBE1(test, usdt_300, x); +} + +__weak void trigger_300_usdts(void) +{ + R100(f300, 0); + R100(f300, 100); + R100(f300, 200); +} + +static void __always_inline f400(int x __attribute__((unused))) +{ + static int y; + + STAP_PROBE1(test, usdt_400, y++); +} + +/* this time we have 400 different USDT call sites, but they have uniform + * argument location, so libbpf's spec string deduplication logic should keep + * spec count use very small and so we should be able to attach to all 400 + * call sites + */ +__weak void trigger_400_usdts(void) +{ + R100(f400, 0); + R100(f400, 100); + R100(f400, 200); + R100(f400, 300); +} + +static void subtest_multispec_usdt(void) +{ + LIBBPF_OPTS(bpf_usdt_opts, opts); + struct test_usdt *skel; + struct test_usdt__bss *bss; + int err, i; + + skel = test_usdt__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + bss = skel->bss; + bss->my_pid = getpid(); + + err = test_usdt__attach(skel); + if (!ASSERT_OK(err, "skel_attach")) + goto cleanup; + + /* usdt_100 is auto-attached and there are 100 inlined call sites, + * let's validate that all of them are properly attached to and + * handled from BPF side + */ + trigger_100_usdts(); + + ASSERT_EQ(bss->usdt_100_called, 100, "usdt_100_called"); + ASSERT_EQ(bss->usdt_100_sum, 99 * 100 / 2, "usdt_100_sum"); + + /* Stress test free spec ID tracking. By default libbpf allows up to + * 256 specs to be used, so if we don't return free spec IDs back + * after few detachments and re-attachments we should run out of + * available spec IDs. + */ + for (i = 0; i < 2; i++) { + bpf_link__destroy(skel->links.usdt_100); + + skel->links.usdt_100 = bpf_program__attach_usdt(skel->progs.usdt_100, -1, + "/proc/self/exe", + "test", "usdt_100", NULL); + if (!ASSERT_OK_PTR(skel->links.usdt_100, "usdt_100_reattach")) + goto cleanup; + + bss->usdt_100_sum = 0; + trigger_100_usdts(); + + ASSERT_EQ(bss->usdt_100_called, (i + 1) * 100 + 100, "usdt_100_called"); + ASSERT_EQ(bss->usdt_100_sum, 99 * 100 / 2, "usdt_100_sum"); + } + + /* Now let's step it up and try to attach USDT that requires more than + * 256 attach points with different specs for each. + * Note that we need trigger_300_usdts() only to actually have 300 + * USDT call sites, we are not going to actually trace them. + */ + trigger_300_usdts(); + + /* we'll reuse usdt_100 BPF program for usdt_300 test */ + bpf_link__destroy(skel->links.usdt_100); + skel->links.usdt_100 = bpf_program__attach_usdt(skel->progs.usdt_100, -1, "/proc/self/exe", + "test", "usdt_300", NULL); + err = -errno; + if (!ASSERT_ERR_PTR(skel->links.usdt_100, "usdt_300_bad_attach")) + goto cleanup; + ASSERT_EQ(err, -E2BIG, "usdt_300_attach_err"); + + /* let's check that there are no "dangling" BPF programs attached due + * to partial success of the above test:usdt_300 attachment + */ + bss->usdt_100_called = 0; + bss->usdt_100_sum = 0; + + f300(777); /* this is 301st instance of usdt_300 */ + + ASSERT_EQ(bss->usdt_100_called, 0, "usdt_301_called"); + ASSERT_EQ(bss->usdt_100_sum, 0, "usdt_301_sum"); + + /* This time we have USDT with 400 inlined invocations, but arg specs + * should be the same across all sites, so libbpf will only need to + * use one spec and thus we'll be able to attach 400 uprobes + * successfully. + * + * Again, we are reusing usdt_100 BPF program. + */ + skel->links.usdt_100 = bpf_program__attach_usdt(skel->progs.usdt_100, -1, + "/proc/self/exe", + "test", "usdt_400", NULL); + if (!ASSERT_OK_PTR(skel->links.usdt_100, "usdt_400_attach")) + goto cleanup; + + trigger_400_usdts(); + + ASSERT_EQ(bss->usdt_100_called, 400, "usdt_400_called"); + ASSERT_EQ(bss->usdt_100_sum, 399 * 400 / 2, "usdt_400_sum"); + +cleanup: + test_usdt__destroy(skel); +} + +static FILE *urand_spawn(int *pid) +{ + FILE *f; + + /* urandom_read's stdout is wired into f */ + f = popen("./urandom_read 1 report-pid", "r"); + if (!f) + return NULL; + + if (fscanf(f, "%d", pid) != 1) { + pclose(f); + return NULL; + } + + return f; +} + +static int urand_trigger(FILE **urand_pipe) +{ + int exit_code; + + /* pclose() waits for child process to exit and returns their exit code */ + exit_code = pclose(*urand_pipe); + *urand_pipe = NULL; + + return exit_code; +} + +static void subtest_urandom_usdt(bool auto_attach) +{ + struct test_urandom_usdt *skel; + struct test_urandom_usdt__bss *bss; + struct bpf_link *l; + FILE *urand_pipe = NULL; + int err, urand_pid = 0; + + skel = test_urandom_usdt__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + urand_pipe = urand_spawn(&urand_pid); + if (!ASSERT_OK_PTR(urand_pipe, "urand_spawn")) + goto cleanup; + + bss = skel->bss; + bss->urand_pid = urand_pid; + + if (auto_attach) { + err = test_urandom_usdt__attach(skel); + if (!ASSERT_OK(err, "skel_auto_attach")) + goto cleanup; + } else { + l = bpf_program__attach_usdt(skel->progs.urand_read_without_sema, + urand_pid, "./urandom_read", + "urand", "read_without_sema", NULL); + if (!ASSERT_OK_PTR(l, "urand_without_sema_attach")) + goto cleanup; + skel->links.urand_read_without_sema = l; + + l = bpf_program__attach_usdt(skel->progs.urand_read_with_sema, + urand_pid, "./urandom_read", + "urand", "read_with_sema", NULL); + if (!ASSERT_OK_PTR(l, "urand_with_sema_attach")) + goto cleanup; + skel->links.urand_read_with_sema = l; + + l = bpf_program__attach_usdt(skel->progs.urandlib_read_without_sema, + urand_pid, "./liburandom_read.so", + "urandlib", "read_without_sema", NULL); + if (!ASSERT_OK_PTR(l, "urandlib_without_sema_attach")) + goto cleanup; + skel->links.urandlib_read_without_sema = l; + + l = bpf_program__attach_usdt(skel->progs.urandlib_read_with_sema, + urand_pid, "./liburandom_read.so", + "urandlib", "read_with_sema", NULL); + if (!ASSERT_OK_PTR(l, "urandlib_with_sema_attach")) + goto cleanup; + skel->links.urandlib_read_with_sema = l; + + } + + /* trigger urandom_read USDTs */ + ASSERT_OK(urand_trigger(&urand_pipe), "urand_exit_code"); + + ASSERT_EQ(bss->urand_read_without_sema_call_cnt, 1, "urand_wo_sema_cnt"); + ASSERT_EQ(bss->urand_read_without_sema_buf_sz_sum, 256, "urand_wo_sema_sum"); + + ASSERT_EQ(bss->urand_read_with_sema_call_cnt, 1, "urand_w_sema_cnt"); + ASSERT_EQ(bss->urand_read_with_sema_buf_sz_sum, 256, "urand_w_sema_sum"); + + ASSERT_EQ(bss->urandlib_read_without_sema_call_cnt, 1, "urandlib_wo_sema_cnt"); + ASSERT_EQ(bss->urandlib_read_without_sema_buf_sz_sum, 256, "urandlib_wo_sema_sum"); + + ASSERT_EQ(bss->urandlib_read_with_sema_call_cnt, 1, "urandlib_w_sema_cnt"); + ASSERT_EQ(bss->urandlib_read_with_sema_buf_sz_sum, 256, "urandlib_w_sema_sum"); + +cleanup: + if (urand_pipe) + pclose(urand_pipe); + test_urandom_usdt__destroy(skel); +} + +void test_usdt(void) +{ + if (test__start_subtest("basic")) + subtest_basic_usdt(); + if (test__start_subtest("multispec")) + subtest_multispec_usdt(); + if (test__start_subtest("urand_auto_attach")) + subtest_urandom_usdt(true /* auto_attach */); + if (test__start_subtest("urand_pid_attach")) + subtest_urandom_usdt(false /* auto_attach */); +} diff --git a/tools/testing/selftests/bpf/progs/for_each_map_elem_write_key.c b/tools/testing/selftests/bpf/progs/for_each_map_elem_write_key.c new file mode 100644 index 000000000000..8e545865ea33 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/for_each_map_elem_write_key.c @@ -0,0 +1,27 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <vmlinux.h> +#include <bpf/bpf_helpers.h> + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u64); +} array_map SEC(".maps"); + +static __u64 +check_array_elem(struct bpf_map *map, __u32 *key, __u64 *val, + void *data) +{ + bpf_get_current_comm(key, sizeof(*key)); + return 0; +} + +SEC("raw_tp/sys_enter") +int test_map_key_write(const void *ctx) +{ + bpf_for_each_map_elem(&array_map, check_array_elem, NULL, 0); + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/linked_funcs1.c b/tools/testing/selftests/bpf/progs/linked_funcs1.c index b964ec1390c2..963b393c37e8 100644 --- a/tools/testing/selftests/bpf/progs/linked_funcs1.c +++ b/tools/testing/selftests/bpf/progs/linked_funcs1.c @@ -4,6 +4,7 @@ #include "vmlinux.h" #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> +#include <bpf/bpf_core_read.h> /* weak and shared between two files */ const volatile int my_tid __weak; @@ -44,6 +45,13 @@ void set_output_ctx1(__u64 *ctx) /* this weak instance should win because it's the first one */ __weak int set_output_weak(int x) { + static volatile int whatever; + + /* make sure we use CO-RE relocations in a weak function, this used to + * cause problems for BPF static linker + */ + whatever = bpf_core_type_size(struct task_struct); + output_weak1 = x; return x; } diff --git a/tools/testing/selftests/bpf/progs/linked_funcs2.c b/tools/testing/selftests/bpf/progs/linked_funcs2.c index 575e958e60b7..db195872f4eb 100644 --- a/tools/testing/selftests/bpf/progs/linked_funcs2.c +++ b/tools/testing/selftests/bpf/progs/linked_funcs2.c @@ -4,6 +4,7 @@ #include "vmlinux.h" #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> +#include <bpf/bpf_core_read.h> /* weak and shared between both files */ const volatile int my_tid __weak; @@ -44,6 +45,13 @@ void set_output_ctx2(__u64 *ctx) /* this weak instance should lose, because it will be processed second */ __weak int set_output_weak(int x) { + static volatile int whatever; + + /* make sure we use CO-RE relocations in a weak function, this used to + * cause problems for BPF static linker + */ + whatever = 2 * bpf_core_type_size(struct task_struct); + output_weak2 = x; return 2 * x; } diff --git a/tools/testing/selftests/bpf/progs/perf_event_stackmap.c b/tools/testing/selftests/bpf/progs/perf_event_stackmap.c index b3fcb5274ee0..f793280a3238 100644 --- a/tools/testing/selftests/bpf/progs/perf_event_stackmap.c +++ b/tools/testing/selftests/bpf/progs/perf_event_stackmap.c @@ -35,10 +35,10 @@ int oncpu(void *ctx) long val; val = bpf_get_stackid(ctx, &stackmap, 0); - if (val > 0) + if (val >= 0) stackid_kernel = 2; val = bpf_get_stackid(ctx, &stackmap, BPF_F_USER_STACK); - if (val > 0) + if (val >= 0) stackid_user = 2; trace = bpf_map_lookup_elem(&stackdata_map, &key); diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h b/tools/testing/selftests/bpf/progs/profiler.inc.h index 4896fdf816f7..92331053dba3 100644 --- a/tools/testing/selftests/bpf/progs/profiler.inc.h +++ b/tools/testing/selftests/bpf/progs/profiler.inc.h @@ -826,8 +826,9 @@ out: SEC("kprobe/vfs_link") int BPF_KPROBE(kprobe__vfs_link, - struct dentry* old_dentry, struct inode* dir, - struct dentry* new_dentry, struct inode** delegated_inode) + struct dentry* old_dentry, struct user_namespace *mnt_userns, + struct inode* dir, struct dentry* new_dentry, + struct inode** delegated_inode) { struct bpf_func_stats_ctx stats_ctx; bpf_stats_enter(&stats_ctx, profiler_bpf_vfs_link); diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c index 8056a4c6d918..af994d16bb10 100644 --- a/tools/testing/selftests/bpf/progs/test_attach_probe.c +++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c @@ -10,6 +10,10 @@ int kprobe_res = 0; int kretprobe_res = 0; int uprobe_res = 0; int uretprobe_res = 0; +int uprobe_byname_res = 0; +int uretprobe_byname_res = 0; +int uprobe_byname2_res = 0; +int uretprobe_byname2_res = 0; SEC("kprobe/sys_nanosleep") int handle_kprobe(struct pt_regs *ctx) @@ -25,18 +29,51 @@ int BPF_KRETPROBE(handle_kretprobe) return 0; } -SEC("uprobe/trigger_func") +SEC("uprobe") int handle_uprobe(struct pt_regs *ctx) { uprobe_res = 3; return 0; } -SEC("uretprobe/trigger_func") +SEC("uretprobe") int handle_uretprobe(struct pt_regs *ctx) { uretprobe_res = 4; return 0; } +SEC("uprobe") +int handle_uprobe_byname(struct pt_regs *ctx) +{ + uprobe_byname_res = 5; + return 0; +} + +/* use auto-attach format for section definition. */ +SEC("uretprobe//proc/self/exe:trigger_func2") +int handle_uretprobe_byname(struct pt_regs *ctx) +{ + uretprobe_byname_res = 6; + return 0; +} + +SEC("uprobe") +int handle_uprobe_byname2(struct pt_regs *ctx) +{ + unsigned int size = PT_REGS_PARM1(ctx); + + /* verify malloc size */ + if (size == 1) + uprobe_byname2_res = 7; + return 0; +} + +SEC("uretprobe") +int handle_uretprobe_byname2(struct pt_regs *ctx) +{ + uretprobe_byname2_res = 8; + return 0; +} + char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/test_bpf_cookie.c b/tools/testing/selftests/bpf/progs/test_bpf_cookie.c index 2d3a7710e2ce..0e2222968918 100644 --- a/tools/testing/selftests/bpf/progs/test_bpf_cookie.c +++ b/tools/testing/selftests/bpf/progs/test_bpf_cookie.c @@ -37,14 +37,14 @@ int handle_kretprobe(struct pt_regs *ctx) return 0; } -SEC("uprobe/trigger_func") +SEC("uprobe") int handle_uprobe(struct pt_regs *ctx) { update(ctx, &uprobe_res); return 0; } -SEC("uretprobe/trigger_func") +SEC("uretprobe") int handle_uretprobe(struct pt_regs *ctx) { update(ctx, &uretprobe_res); diff --git a/tools/testing/selftests/bpf/progs/test_global_func17.c b/tools/testing/selftests/bpf/progs/test_global_func17.c new file mode 100644 index 000000000000..2b8b9b8ba018 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_global_func17.c @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <vmlinux.h> +#include <bpf/bpf_helpers.h> + +__noinline int foo(int *p) +{ + return p ? (*p = 42) : 0; +} + +const volatile int i; + +SEC("tc") +int test_cls(struct __sk_buff *skb) +{ + return foo((int *)&i); +} diff --git a/tools/testing/selftests/bpf/progs/test_ksyms_btf_write_check.c b/tools/testing/selftests/bpf/progs/test_ksyms_btf_write_check.c index 2180c41cd890..a72a5bf3812a 100644 --- a/tools/testing/selftests/bpf/progs/test_ksyms_btf_write_check.c +++ b/tools/testing/selftests/bpf/progs/test_ksyms_btf_write_check.c @@ -8,7 +8,7 @@ extern const int bpf_prog_active __ksym; /* int type global var. */ SEC("raw_tp/sys_enter") -int handler(const void *ctx) +int handler1(const void *ctx) { int *active; __u32 cpu; @@ -26,4 +26,20 @@ int handler(const void *ctx) return 0; } +__noinline int write_active(int *p) +{ + return p ? (*p = 42) : 0; +} + +SEC("raw_tp/sys_enter") +int handler2(const void *ctx) +{ + int *active; + __u32 cpu; + + active = bpf_this_cpu_ptr(&bpf_prog_active); + write_active(active); + return 0; +} + char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/test_l4lb_noinline.c b/tools/testing/selftests/bpf/progs/test_l4lb_noinline.c index 19e4d2071c60..c8bc0c6947aa 100644 --- a/tools/testing/selftests/bpf/progs/test_l4lb_noinline.c +++ b/tools/testing/selftests/bpf/progs/test_l4lb_noinline.c @@ -218,7 +218,7 @@ static __noinline bool get_packet_dst(struct real_definition **real, if (hash != 0x358459b7 /* jhash of ipv4 packet */ && hash != 0x2f4bc6bb /* jhash of ipv6 packet */) - return 0; + return false; real_pos = bpf_map_lookup_elem(&ch_rings, &key); if (!real_pos) diff --git a/tools/testing/selftests/bpf/progs/test_sk_assign.c b/tools/testing/selftests/bpf/progs/test_sk_assign.c index 02f79356d5eb..98c6493d9b91 100644 --- a/tools/testing/selftests/bpf/progs/test_sk_assign.c +++ b/tools/testing/selftests/bpf/progs/test_sk_assign.c @@ -89,7 +89,6 @@ get_tuple(struct __sk_buff *skb, bool *ipv4, bool *tcp) static inline int handle_udp(struct __sk_buff *skb, struct bpf_sock_tuple *tuple, bool ipv4) { - struct bpf_sock_tuple ln = {0}; struct bpf_sock *sk; const int zero = 0; size_t tuple_len; @@ -121,7 +120,6 @@ assign: static inline int handle_tcp(struct __sk_buff *skb, struct bpf_sock_tuple *tuple, bool ipv4) { - struct bpf_sock_tuple ln = {0}; struct bpf_sock *sk; const int zero = 0; size_t tuple_len; @@ -161,7 +159,7 @@ assign: SEC("tc") int bpf_sk_assign_test(struct __sk_buff *skb) { - struct bpf_sock_tuple *tuple, ln = {0}; + struct bpf_sock_tuple *tuple; bool ipv4 = false; bool tcp = false; int tuple_len; diff --git a/tools/testing/selftests/bpf/progs/test_task_pt_regs.c b/tools/testing/selftests/bpf/progs/test_task_pt_regs.c index e6cb09259408..1926facba122 100644 --- a/tools/testing/selftests/bpf/progs/test_task_pt_regs.c +++ b/tools/testing/selftests/bpf/progs/test_task_pt_regs.c @@ -14,7 +14,7 @@ char current_regs[PT_REGS_SIZE] = {}; char ctx_regs[PT_REGS_SIZE] = {}; int uprobe_res = 0; -SEC("uprobe/trigger_func") +SEC("uprobe") int handle_uprobe(struct pt_regs *ctx) { struct task_struct *current; diff --git a/tools/testing/selftests/bpf/progs/test_uprobe_autoattach.c b/tools/testing/selftests/bpf/progs/test_uprobe_autoattach.c new file mode 100644 index 000000000000..ab75522e2eeb --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_uprobe_autoattach.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022, Oracle and/or its affiliates. */ + +#include "vmlinux.h" + +#include <bpf/bpf_core_read.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +int uprobe_byname_parm1 = 0; +int uprobe_byname_ran = 0; +int uretprobe_byname_rc = 0; +int uretprobe_byname_ran = 0; +size_t uprobe_byname2_parm1 = 0; +int uprobe_byname2_ran = 0; +char *uretprobe_byname2_rc = NULL; +int uretprobe_byname2_ran = 0; + +int test_pid; + +/* This program cannot auto-attach, but that should not stop other + * programs from attaching. + */ +SEC("uprobe") +int handle_uprobe_noautoattach(struct pt_regs *ctx) +{ + return 0; +} + +SEC("uprobe//proc/self/exe:autoattach_trigger_func") +int handle_uprobe_byname(struct pt_regs *ctx) +{ + uprobe_byname_parm1 = PT_REGS_PARM1_CORE(ctx); + uprobe_byname_ran = 1; + return 0; +} + +SEC("uretprobe//proc/self/exe:autoattach_trigger_func") +int handle_uretprobe_byname(struct pt_regs *ctx) +{ + uretprobe_byname_rc = PT_REGS_RC_CORE(ctx); + uretprobe_byname_ran = 2; + return 0; +} + + +SEC("uprobe/libc.so.6:malloc") +int handle_uprobe_byname2(struct pt_regs *ctx) +{ + int pid = bpf_get_current_pid_tgid() >> 32; + + /* ignore irrelevant invocations */ + if (test_pid != pid) + return 0; + uprobe_byname2_parm1 = PT_REGS_PARM1_CORE(ctx); + uprobe_byname2_ran = 3; + return 0; +} + +SEC("uretprobe/libc.so.6:malloc") +int handle_uretprobe_byname2(struct pt_regs *ctx) +{ + int pid = bpf_get_current_pid_tgid() >> 32; + + /* ignore irrelevant invocations */ + if (test_pid != pid) + return 0; + uretprobe_byname2_rc = (char *)PT_REGS_RC_CORE(ctx); + uretprobe_byname2_ran = 4; + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/test_urandom_usdt.c b/tools/testing/selftests/bpf/progs/test_urandom_usdt.c new file mode 100644 index 000000000000..3539b02bd5f7 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_urandom_usdt.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ + +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/usdt.bpf.h> + +int urand_pid; + +int urand_read_without_sema_call_cnt; +int urand_read_without_sema_buf_sz_sum; + +SEC("usdt/./urandom_read:urand:read_without_sema") +int BPF_USDT(urand_read_without_sema, int iter_num, int iter_cnt, int buf_sz) +{ + if (urand_pid != (bpf_get_current_pid_tgid() >> 32)) + return 0; + + __sync_fetch_and_add(&urand_read_without_sema_call_cnt, 1); + __sync_fetch_and_add(&urand_read_without_sema_buf_sz_sum, buf_sz); + + return 0; +} + +int urand_read_with_sema_call_cnt; +int urand_read_with_sema_buf_sz_sum; + +SEC("usdt/./urandom_read:urand:read_with_sema") +int BPF_USDT(urand_read_with_sema, int iter_num, int iter_cnt, int buf_sz) +{ + if (urand_pid != (bpf_get_current_pid_tgid() >> 32)) + return 0; + + __sync_fetch_and_add(&urand_read_with_sema_call_cnt, 1); + __sync_fetch_and_add(&urand_read_with_sema_buf_sz_sum, buf_sz); + + return 0; +} + +int urandlib_read_without_sema_call_cnt; +int urandlib_read_without_sema_buf_sz_sum; + +SEC("usdt/./liburandom_read.so:urandlib:read_without_sema") +int BPF_USDT(urandlib_read_without_sema, int iter_num, int iter_cnt, int buf_sz) +{ + if (urand_pid != (bpf_get_current_pid_tgid() >> 32)) + return 0; + + __sync_fetch_and_add(&urandlib_read_without_sema_call_cnt, 1); + __sync_fetch_and_add(&urandlib_read_without_sema_buf_sz_sum, buf_sz); + + return 0; +} + +int urandlib_read_with_sema_call_cnt; +int urandlib_read_with_sema_buf_sz_sum; + +SEC("usdt/./liburandom_read.so:urandlib:read_with_sema") +int BPF_USDT(urandlib_read_with_sema, int iter_num, int iter_cnt, int buf_sz) +{ + if (urand_pid != (bpf_get_current_pid_tgid() >> 32)) + return 0; + + __sync_fetch_and_add(&urandlib_read_with_sema_call_cnt, 1); + __sync_fetch_and_add(&urandlib_read_with_sema_buf_sz_sum, buf_sz); + + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/test_usdt.c b/tools/testing/selftests/bpf/progs/test_usdt.c new file mode 100644 index 000000000000..505aab9a5234 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_usdt.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ + +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/usdt.bpf.h> + +int my_pid; + +int usdt0_called; +u64 usdt0_cookie; +int usdt0_arg_cnt; +int usdt0_arg_ret; + +SEC("usdt") +int usdt0(struct pt_regs *ctx) +{ + long tmp; + + if (my_pid != (bpf_get_current_pid_tgid() >> 32)) + return 0; + + __sync_fetch_and_add(&usdt0_called, 1); + + usdt0_cookie = bpf_usdt_cookie(ctx); + usdt0_arg_cnt = bpf_usdt_arg_cnt(ctx); + /* should return -ENOENT for any arg_num */ + usdt0_arg_ret = bpf_usdt_arg(ctx, bpf_get_prandom_u32(), &tmp); + return 0; +} + +int usdt3_called; +u64 usdt3_cookie; +int usdt3_arg_cnt; +int usdt3_arg_rets[3]; +u64 usdt3_args[3]; + +SEC("usdt//proc/self/exe:test:usdt3") +int usdt3(struct pt_regs *ctx) +{ + long tmp; + + if (my_pid != (bpf_get_current_pid_tgid() >> 32)) + return 0; + + __sync_fetch_and_add(&usdt3_called, 1); + + usdt3_cookie = bpf_usdt_cookie(ctx); + usdt3_arg_cnt = bpf_usdt_arg_cnt(ctx); + + usdt3_arg_rets[0] = bpf_usdt_arg(ctx, 0, &tmp); + usdt3_args[0] = (int)tmp; + + usdt3_arg_rets[1] = bpf_usdt_arg(ctx, 1, &tmp); + usdt3_args[1] = (long)tmp; + + usdt3_arg_rets[2] = bpf_usdt_arg(ctx, 2, &tmp); + usdt3_args[2] = (uintptr_t)tmp; + + return 0; +} + +int usdt12_called; +u64 usdt12_cookie; +int usdt12_arg_cnt; +u64 usdt12_args[12]; + +SEC("usdt//proc/self/exe:test:usdt12") +int BPF_USDT(usdt12, int a1, int a2, long a3, long a4, unsigned a5, + long a6, __u64 a7, uintptr_t a8, int a9, short a10, + short a11, signed char a12) +{ + if (my_pid != (bpf_get_current_pid_tgid() >> 32)) + return 0; + + __sync_fetch_and_add(&usdt12_called, 1); + + usdt12_cookie = bpf_usdt_cookie(ctx); + usdt12_arg_cnt = bpf_usdt_arg_cnt(ctx); + + usdt12_args[0] = a1; + usdt12_args[1] = a2; + usdt12_args[2] = a3; + usdt12_args[3] = a4; + usdt12_args[4] = a5; + usdt12_args[5] = a6; + usdt12_args[6] = a7; + usdt12_args[7] = a8; + usdt12_args[8] = a9; + usdt12_args[9] = a10; + usdt12_args[10] = a11; + usdt12_args[11] = a12; + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/test_usdt_multispec.c b/tools/testing/selftests/bpf/progs/test_usdt_multispec.c new file mode 100644 index 000000000000..aa6de32b50d1 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_usdt_multispec.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ + +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/usdt.bpf.h> + +/* this file is linked together with test_usdt.c to validate that usdt.bpf.h + * can be included in multiple .bpf.c files forming single final BPF object + * file + */ + +extern int my_pid; + +int usdt_100_called; +int usdt_100_sum; + +SEC("usdt//proc/self/exe:test:usdt_100") +int BPF_USDT(usdt_100, int x) +{ + long tmp; + + if (my_pid != (bpf_get_current_pid_tgid() >> 32)) + return 0; + + __sync_fetch_and_add(&usdt_100_called, 1); + __sync_fetch_and_add(&usdt_100_sum, x); + + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/test_xdp_noinline.c b/tools/testing/selftests/bpf/progs/test_xdp_noinline.c index 596c4e71bf3a..125d872d7981 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_noinline.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_noinline.c @@ -564,22 +564,22 @@ static bool get_packet_dst(struct real_definition **real, hash = get_packet_hash(pckt, hash_16bytes); if (hash != 0x358459b7 /* jhash of ipv4 packet */ && hash != 0x2f4bc6bb /* jhash of ipv6 packet */) - return 0; + return false; key = 2 * vip_info->vip_num + hash % 2; real_pos = bpf_map_lookup_elem(&ch_rings, &key); if (!real_pos) - return 0; + return false; key = *real_pos; *real = bpf_map_lookup_elem(&reals, &key); if (!(*real)) - return 0; + return false; if (!(vip_info->flags & (1 << 1))) { __u32 conn_rate_key = 512 + 2; struct lb_stats *conn_rate_stats = bpf_map_lookup_elem(&stats, &conn_rate_key); if (!conn_rate_stats) - return 1; + return true; cur_time = bpf_ktime_get_ns(); if ((cur_time - conn_rate_stats->v2) >> 32 > 0xffFFFF) { conn_rate_stats->v1 = 1; @@ -587,14 +587,14 @@ static bool get_packet_dst(struct real_definition **real, } else { conn_rate_stats->v1 += 1; if (conn_rate_stats->v1 >= 1) - return 1; + return true; } if (pckt->flow.proto == IPPROTO_UDP) new_dst_lru.atime = cur_time; new_dst_lru.pos = key; bpf_map_update_elem(lru_map, &pckt->flow, &new_dst_lru, 0); } - return 1; + return true; } __attribute__ ((noinline)) diff --git a/tools/testing/selftests/bpf/progs/trigger_bench.c b/tools/testing/selftests/bpf/progs/trigger_bench.c index 2ab049b54d6c..694e7cec1823 100644 --- a/tools/testing/selftests/bpf/progs/trigger_bench.c +++ b/tools/testing/selftests/bpf/progs/trigger_bench.c @@ -54,7 +54,7 @@ int bench_trigger_fmodret(void *ctx) return -22; } -SEC("uprobe/self/uprobe_target") +SEC("uprobe") int bench_trigger_uprobe(void *ctx) { __sync_add_and_fetch(&hits, 1); diff --git a/tools/testing/selftests/bpf/sdt-config.h b/tools/testing/selftests/bpf/sdt-config.h new file mode 100644 index 000000000000..733045a52771 --- /dev/null +++ b/tools/testing/selftests/bpf/sdt-config.h @@ -0,0 +1,6 @@ +/* includes/sys/sdt-config.h. Generated from sdt-config.h.in by configure. + + This file just defines _SDT_ASM_SECTION_AUTOGROUP_SUPPORT to 0 or 1 to + indicate whether the assembler supports "?" in .pushsection directives. */ + +#define _SDT_ASM_SECTION_AUTOGROUP_SUPPORT 1 diff --git a/tools/testing/selftests/bpf/sdt.h b/tools/testing/selftests/bpf/sdt.h new file mode 100644 index 000000000000..ca0162b4dc57 --- /dev/null +++ b/tools/testing/selftests/bpf/sdt.h @@ -0,0 +1,513 @@ +/* <sys/sdt.h> - Systemtap static probe definition macros. + + This file is dedicated to the public domain, pursuant to CC0 + (https://creativecommons.org/publicdomain/zero/1.0/) +*/ + +#ifndef _SYS_SDT_H +#define _SYS_SDT_H 1 + +/* + This file defines a family of macros + + STAP_PROBEn(op1, ..., opn) + + that emit a nop into the instruction stream, and some data into an auxiliary + note section. The data in the note section describes the operands, in terms + of size and location. Each location is encoded as assembler operand string. + Consumer tools such as gdb or systemtap insert breakpoints on top of + the nop, and decode the location operand-strings, like an assembler, + to find the values being passed. + + The operand strings are selected by the compiler for each operand. + They are constrained by gcc inline-assembler codes. The default is: + + #define STAP_SDT_ARG_CONSTRAINT nor + + This is a good default if the operands tend to be integral and + moderate in number (smaller than number of registers). In other + cases, the compiler may report "'asm' requires impossible reload" or + similar. In this case, consider simplifying the macro call (fewer + and simpler operands), reduce optimization, or override the default + constraints string via: + + #define STAP_SDT_ARG_CONSTRAINT g + #include <sys/sdt.h> + + See also: + https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation + https://gcc.gnu.org/onlinedocs/gcc/Constraints.html + */ + + + +#ifdef __ASSEMBLER__ +# define _SDT_PROBE(provider, name, n, arglist) \ + _SDT_ASM_BODY(provider, name, _SDT_ASM_SUBSTR_1, (_SDT_DEPAREN_##n arglist)) \ + _SDT_ASM_BASE +# define _SDT_ASM_1(x) x; +# define _SDT_ASM_2(a, b) a,b; +# define _SDT_ASM_3(a, b, c) a,b,c; +# define _SDT_ASM_5(a, b, c, d, e) a,b,c,d,e; +# define _SDT_ASM_STRING_1(x) .asciz #x; +# define _SDT_ASM_SUBSTR_1(x) .ascii #x; +# define _SDT_DEPAREN_0() /* empty */ +# define _SDT_DEPAREN_1(a) a +# define _SDT_DEPAREN_2(a,b) a b +# define _SDT_DEPAREN_3(a,b,c) a b c +# define _SDT_DEPAREN_4(a,b,c,d) a b c d +# define _SDT_DEPAREN_5(a,b,c,d,e) a b c d e +# define _SDT_DEPAREN_6(a,b,c,d,e,f) a b c d e f +# define _SDT_DEPAREN_7(a,b,c,d,e,f,g) a b c d e f g +# define _SDT_DEPAREN_8(a,b,c,d,e,f,g,h) a b c d e f g h +# define _SDT_DEPAREN_9(a,b,c,d,e,f,g,h,i) a b c d e f g h i +# define _SDT_DEPAREN_10(a,b,c,d,e,f,g,h,i,j) a b c d e f g h i j +# define _SDT_DEPAREN_11(a,b,c,d,e,f,g,h,i,j,k) a b c d e f g h i j k +# define _SDT_DEPAREN_12(a,b,c,d,e,f,g,h,i,j,k,l) a b c d e f g h i j k l +#else +#if defined _SDT_HAS_SEMAPHORES +#define _SDT_NOTE_SEMAPHORE_USE(provider, name) \ + __asm__ __volatile__ ("" :: "m" (provider##_##name##_semaphore)); +#else +#define _SDT_NOTE_SEMAPHORE_USE(provider, name) +#endif + +# define _SDT_PROBE(provider, name, n, arglist) \ + do { \ + _SDT_NOTE_SEMAPHORE_USE(provider, name); \ + __asm__ __volatile__ (_SDT_ASM_BODY(provider, name, _SDT_ASM_ARGS, (n)) \ + :: _SDT_ASM_OPERANDS_##n arglist); \ + __asm__ __volatile__ (_SDT_ASM_BASE); \ + } while (0) +# define _SDT_S(x) #x +# define _SDT_ASM_1(x) _SDT_S(x) "\n" +# define _SDT_ASM_2(a, b) _SDT_S(a) "," _SDT_S(b) "\n" +# define _SDT_ASM_3(a, b, c) _SDT_S(a) "," _SDT_S(b) "," \ + _SDT_S(c) "\n" +# define _SDT_ASM_5(a, b, c, d, e) _SDT_S(a) "," _SDT_S(b) "," \ + _SDT_S(c) "," _SDT_S(d) "," \ + _SDT_S(e) "\n" +# define _SDT_ASM_ARGS(n) _SDT_ASM_TEMPLATE_##n +# define _SDT_ASM_STRING_1(x) _SDT_ASM_1(.asciz #x) +# define _SDT_ASM_SUBSTR_1(x) _SDT_ASM_1(.ascii #x) + +# define _SDT_ARGFMT(no) _SDT_ASM_1(_SDT_SIGN %n[_SDT_S##no]) \ + _SDT_ASM_1(_SDT_SIZE %n[_SDT_S##no]) \ + _SDT_ASM_1(_SDT_TYPE %n[_SDT_S##no]) \ + _SDT_ASM_SUBSTR(_SDT_ARGTMPL(_SDT_A##no)) + + +# ifndef STAP_SDT_ARG_CONSTRAINT +# if defined __powerpc__ +# define STAP_SDT_ARG_CONSTRAINT nZr +# elif defined __arm__ +# define STAP_SDT_ARG_CONSTRAINT g +# else +# define STAP_SDT_ARG_CONSTRAINT nor +# endif +# endif + +# define _SDT_STRINGIFY(x) #x +# define _SDT_ARG_CONSTRAINT_STRING(x) _SDT_STRINGIFY(x) +/* _SDT_S encodes the size and type as 0xSSTT which is decoded by the assembler + macros _SDT_SIZE and _SDT_TYPE */ +# define _SDT_ARG(n, x) \ + [_SDT_S##n] "n" ((_SDT_ARGSIGNED (x) ? (int)-1 : 1) * (-(((int) _SDT_ARGSIZE (x)) << 8) + (-(0x7f & __builtin_classify_type (x))))), \ + [_SDT_A##n] _SDT_ARG_CONSTRAINT_STRING (STAP_SDT_ARG_CONSTRAINT) (_SDT_ARGVAL (x)) +#endif +#define _SDT_ASM_STRING(x) _SDT_ASM_STRING_1(x) +#define _SDT_ASM_SUBSTR(x) _SDT_ASM_SUBSTR_1(x) + +#define _SDT_ARGARRAY(x) (__builtin_classify_type (x) == 14 \ + || __builtin_classify_type (x) == 5) + +#ifdef __cplusplus +# define _SDT_ARGSIGNED(x) (!_SDT_ARGARRAY (x) \ + && __sdt_type<__typeof (x)>::__sdt_signed) +# define _SDT_ARGSIZE(x) (_SDT_ARGARRAY (x) \ + ? sizeof (void *) : sizeof (x)) +# define _SDT_ARGVAL(x) (x) + +# include <cstddef> + +template<typename __sdt_T> +struct __sdt_type +{ + static const bool __sdt_signed = false; +}; + +#define __SDT_ALWAYS_SIGNED(T) \ +template<> struct __sdt_type<T> { static const bool __sdt_signed = true; }; +#define __SDT_COND_SIGNED(T,CT) \ +template<> struct __sdt_type<T> { static const bool __sdt_signed = ((CT)(-1) < 1); }; +__SDT_ALWAYS_SIGNED(signed char) +__SDT_ALWAYS_SIGNED(short) +__SDT_ALWAYS_SIGNED(int) +__SDT_ALWAYS_SIGNED(long) +__SDT_ALWAYS_SIGNED(long long) +__SDT_ALWAYS_SIGNED(volatile signed char) +__SDT_ALWAYS_SIGNED(volatile short) +__SDT_ALWAYS_SIGNED(volatile int) +__SDT_ALWAYS_SIGNED(volatile long) +__SDT_ALWAYS_SIGNED(volatile long long) +__SDT_ALWAYS_SIGNED(const signed char) +__SDT_ALWAYS_SIGNED(const short) +__SDT_ALWAYS_SIGNED(const int) +__SDT_ALWAYS_SIGNED(const long) +__SDT_ALWAYS_SIGNED(const long long) +__SDT_ALWAYS_SIGNED(const volatile signed char) +__SDT_ALWAYS_SIGNED(const volatile short) +__SDT_ALWAYS_SIGNED(const volatile int) +__SDT_ALWAYS_SIGNED(const volatile long) +__SDT_ALWAYS_SIGNED(const volatile long long) +__SDT_COND_SIGNED(char, char) +__SDT_COND_SIGNED(wchar_t, wchar_t) +__SDT_COND_SIGNED(volatile char, char) +__SDT_COND_SIGNED(volatile wchar_t, wchar_t) +__SDT_COND_SIGNED(const char, char) +__SDT_COND_SIGNED(const wchar_t, wchar_t) +__SDT_COND_SIGNED(const volatile char, char) +__SDT_COND_SIGNED(const volatile wchar_t, wchar_t) +#if defined (__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4)) +/* __SDT_COND_SIGNED(char16_t) */ +/* __SDT_COND_SIGNED(char32_t) */ +#endif + +template<typename __sdt_E> +struct __sdt_type<__sdt_E[]> : public __sdt_type<__sdt_E *> {}; + +template<typename __sdt_E, size_t __sdt_N> +struct __sdt_type<__sdt_E[__sdt_N]> : public __sdt_type<__sdt_E *> {}; + +#elif !defined(__ASSEMBLER__) +__extension__ extern unsigned long long __sdt_unsp; +# define _SDT_ARGINTTYPE(x) \ + __typeof (__builtin_choose_expr (((__builtin_classify_type (x) \ + + 3) & -4) == 4, (x), 0U)) +# define _SDT_ARGSIGNED(x) \ + (!__extension__ \ + (__builtin_constant_p ((((unsigned long long) \ + (_SDT_ARGINTTYPE (x)) __sdt_unsp) \ + & ((unsigned long long)1 << (sizeof (unsigned long long) \ + * __CHAR_BIT__ - 1))) == 0) \ + || (_SDT_ARGINTTYPE (x)) -1 > (_SDT_ARGINTTYPE (x)) 0)) +# define _SDT_ARGSIZE(x) \ + (_SDT_ARGARRAY (x) ? sizeof (void *) : sizeof (x)) +# define _SDT_ARGVAL(x) (x) +#endif + +#if defined __powerpc__ || defined __powerpc64__ +# define _SDT_ARGTMPL(id) %I[id]%[id] +#elif defined __i386__ +# define _SDT_ARGTMPL(id) %k[id] /* gcc.gnu.org/PR80115 sourceware.org/PR24541 */ +#else +# define _SDT_ARGTMPL(id) %[id] +#endif + +/* NB: gdb PR24541 highlighted an unspecified corner of the sdt.h + operand note format. + + The named register may be a longer or shorter (!) alias for the + storage where the value in question is found. For example, on + i386, 64-bit value may be put in register pairs, and the register + name stored would identify just one of them. Previously, gcc was + asked to emit the %w[id] (16-bit alias of some registers holding + operands), even when a wider 32-bit value was used. + + Bottom line: the byte-width given before the @ sign governs. If + there is a mismatch between that width and that of the named + register, then a sys/sdt.h note consumer may need to employ + architecture-specific heuristics to figure out where the compiler + has actually put the complete value. +*/ + +#ifdef __LP64__ +# define _SDT_ASM_ADDR .8byte +#else +# define _SDT_ASM_ADDR .4byte +#endif + +/* The ia64 and s390 nop instructions take an argument. */ +#if defined(__ia64__) || defined(__s390__) || defined(__s390x__) +#define _SDT_NOP nop 0 +#else +#define _SDT_NOP nop +#endif + +#define _SDT_NOTE_NAME "stapsdt" +#define _SDT_NOTE_TYPE 3 + +/* If the assembler supports the necessary feature, then we can play + nice with code in COMDAT sections, which comes up in C++ code. + Without that assembler support, some combinations of probe placements + in certain kinds of C++ code may produce link-time errors. */ +#include "sdt-config.h" +#if _SDT_ASM_SECTION_AUTOGROUP_SUPPORT +# define _SDT_ASM_AUTOGROUP "?" +#else +# define _SDT_ASM_AUTOGROUP "" +#endif + +#define _SDT_DEF_MACROS \ + _SDT_ASM_1(.altmacro) \ + _SDT_ASM_1(.macro _SDT_SIGN x) \ + _SDT_ASM_3(.pushsection .note.stapsdt,"","note") \ + _SDT_ASM_1(.iflt \\x) \ + _SDT_ASM_1(.ascii "-") \ + _SDT_ASM_1(.endif) \ + _SDT_ASM_1(.popsection) \ + _SDT_ASM_1(.endm) \ + _SDT_ASM_1(.macro _SDT_SIZE_ x) \ + _SDT_ASM_3(.pushsection .note.stapsdt,"","note") \ + _SDT_ASM_1(.ascii "\x") \ + _SDT_ASM_1(.popsection) \ + _SDT_ASM_1(.endm) \ + _SDT_ASM_1(.macro _SDT_SIZE x) \ + _SDT_ASM_1(_SDT_SIZE_ %%((-(-\\x*((-\\x>0)-(-\\x<0))))>>8)) \ + _SDT_ASM_1(.endm) \ + _SDT_ASM_1(.macro _SDT_TYPE_ x) \ + _SDT_ASM_3(.pushsection .note.stapsdt,"","note") \ + _SDT_ASM_2(.ifc 8,\\x) \ + _SDT_ASM_1(.ascii "f") \ + _SDT_ASM_1(.endif) \ + _SDT_ASM_1(.ascii "@") \ + _SDT_ASM_1(.popsection) \ + _SDT_ASM_1(.endm) \ + _SDT_ASM_1(.macro _SDT_TYPE x) \ + _SDT_ASM_1(_SDT_TYPE_ %%((\\x)&(0xff))) \ + _SDT_ASM_1(.endm) + +#define _SDT_UNDEF_MACROS \ + _SDT_ASM_1(.purgem _SDT_SIGN) \ + _SDT_ASM_1(.purgem _SDT_SIZE_) \ + _SDT_ASM_1(.purgem _SDT_SIZE) \ + _SDT_ASM_1(.purgem _SDT_TYPE_) \ + _SDT_ASM_1(.purgem _SDT_TYPE) + +#define _SDT_ASM_BODY(provider, name, pack_args, args, ...) \ + _SDT_DEF_MACROS \ + _SDT_ASM_1(990: _SDT_NOP) \ + _SDT_ASM_3( .pushsection .note.stapsdt,_SDT_ASM_AUTOGROUP,"note") \ + _SDT_ASM_1( .balign 4) \ + _SDT_ASM_3( .4byte 992f-991f, 994f-993f, _SDT_NOTE_TYPE) \ + _SDT_ASM_1(991: .asciz _SDT_NOTE_NAME) \ + _SDT_ASM_1(992: .balign 4) \ + _SDT_ASM_1(993: _SDT_ASM_ADDR 990b) \ + _SDT_ASM_1( _SDT_ASM_ADDR _.stapsdt.base) \ + _SDT_SEMAPHORE(provider,name) \ + _SDT_ASM_STRING(provider) \ + _SDT_ASM_STRING(name) \ + pack_args args \ + _SDT_ASM_SUBSTR(\x00) \ + _SDT_UNDEF_MACROS \ + _SDT_ASM_1(994: .balign 4) \ + _SDT_ASM_1( .popsection) + +#define _SDT_ASM_BASE \ + _SDT_ASM_1(.ifndef _.stapsdt.base) \ + _SDT_ASM_5( .pushsection .stapsdt.base,"aG","progbits", \ + .stapsdt.base,comdat) \ + _SDT_ASM_1( .weak _.stapsdt.base) \ + _SDT_ASM_1( .hidden _.stapsdt.base) \ + _SDT_ASM_1( _.stapsdt.base: .space 1) \ + _SDT_ASM_2( .size _.stapsdt.base, 1) \ + _SDT_ASM_1( .popsection) \ + _SDT_ASM_1(.endif) + +#if defined _SDT_HAS_SEMAPHORES +#define _SDT_SEMAPHORE(p,n) \ + _SDT_ASM_1( _SDT_ASM_ADDR p##_##n##_semaphore) +#else +#define _SDT_SEMAPHORE(p,n) _SDT_ASM_1( _SDT_ASM_ADDR 0) +#endif + +#define _SDT_ASM_BLANK _SDT_ASM_SUBSTR(\x20) +#define _SDT_ASM_TEMPLATE_0 /* no arguments */ +#define _SDT_ASM_TEMPLATE_1 _SDT_ARGFMT(1) +#define _SDT_ASM_TEMPLATE_2 _SDT_ASM_TEMPLATE_1 _SDT_ASM_BLANK _SDT_ARGFMT(2) +#define _SDT_ASM_TEMPLATE_3 _SDT_ASM_TEMPLATE_2 _SDT_ASM_BLANK _SDT_ARGFMT(3) +#define _SDT_ASM_TEMPLATE_4 _SDT_ASM_TEMPLATE_3 _SDT_ASM_BLANK _SDT_ARGFMT(4) +#define _SDT_ASM_TEMPLATE_5 _SDT_ASM_TEMPLATE_4 _SDT_ASM_BLANK _SDT_ARGFMT(5) +#define _SDT_ASM_TEMPLATE_6 _SDT_ASM_TEMPLATE_5 _SDT_ASM_BLANK _SDT_ARGFMT(6) +#define _SDT_ASM_TEMPLATE_7 _SDT_ASM_TEMPLATE_6 _SDT_ASM_BLANK _SDT_ARGFMT(7) +#define _SDT_ASM_TEMPLATE_8 _SDT_ASM_TEMPLATE_7 _SDT_ASM_BLANK _SDT_ARGFMT(8) +#define _SDT_ASM_TEMPLATE_9 _SDT_ASM_TEMPLATE_8 _SDT_ASM_BLANK _SDT_ARGFMT(9) +#define _SDT_ASM_TEMPLATE_10 _SDT_ASM_TEMPLATE_9 _SDT_ASM_BLANK _SDT_ARGFMT(10) +#define _SDT_ASM_TEMPLATE_11 _SDT_ASM_TEMPLATE_10 _SDT_ASM_BLANK _SDT_ARGFMT(11) +#define _SDT_ASM_TEMPLATE_12 _SDT_ASM_TEMPLATE_11 _SDT_ASM_BLANK _SDT_ARGFMT(12) +#define _SDT_ASM_OPERANDS_0() [__sdt_dummy] "g" (0) +#define _SDT_ASM_OPERANDS_1(arg1) _SDT_ARG(1, arg1) +#define _SDT_ASM_OPERANDS_2(arg1, arg2) \ + _SDT_ASM_OPERANDS_1(arg1), _SDT_ARG(2, arg2) +#define _SDT_ASM_OPERANDS_3(arg1, arg2, arg3) \ + _SDT_ASM_OPERANDS_2(arg1, arg2), _SDT_ARG(3, arg3) +#define _SDT_ASM_OPERANDS_4(arg1, arg2, arg3, arg4) \ + _SDT_ASM_OPERANDS_3(arg1, arg2, arg3), _SDT_ARG(4, arg4) +#define _SDT_ASM_OPERANDS_5(arg1, arg2, arg3, arg4, arg5) \ + _SDT_ASM_OPERANDS_4(arg1, arg2, arg3, arg4), _SDT_ARG(5, arg5) +#define _SDT_ASM_OPERANDS_6(arg1, arg2, arg3, arg4, arg5, arg6) \ + _SDT_ASM_OPERANDS_5(arg1, arg2, arg3, arg4, arg5), _SDT_ARG(6, arg6) +#define _SDT_ASM_OPERANDS_7(arg1, arg2, arg3, arg4, arg5, arg6, arg7) \ + _SDT_ASM_OPERANDS_6(arg1, arg2, arg3, arg4, arg5, arg6), _SDT_ARG(7, arg7) +#define _SDT_ASM_OPERANDS_8(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \ + _SDT_ASM_OPERANDS_7(arg1, arg2, arg3, arg4, arg5, arg6, arg7), \ + _SDT_ARG(8, arg8) +#define _SDT_ASM_OPERANDS_9(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9) \ + _SDT_ASM_OPERANDS_8(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8), \ + _SDT_ARG(9, arg9) +#define _SDT_ASM_OPERANDS_10(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10) \ + _SDT_ASM_OPERANDS_9(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9), \ + _SDT_ARG(10, arg10) +#define _SDT_ASM_OPERANDS_11(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11) \ + _SDT_ASM_OPERANDS_10(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10), \ + _SDT_ARG(11, arg11) +#define _SDT_ASM_OPERANDS_12(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11,arg12) \ + _SDT_ASM_OPERANDS_11(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11), \ + _SDT_ARG(12, arg12) + +/* These macros can be used in C, C++, or assembly code. + In assembly code the arguments should use normal assembly operand syntax. */ + +#define STAP_PROBE(provider, name) \ + _SDT_PROBE(provider, name, 0, ()) +#define STAP_PROBE1(provider, name, arg1) \ + _SDT_PROBE(provider, name, 1, (arg1)) +#define STAP_PROBE2(provider, name, arg1, arg2) \ + _SDT_PROBE(provider, name, 2, (arg1, arg2)) +#define STAP_PROBE3(provider, name, arg1, arg2, arg3) \ + _SDT_PROBE(provider, name, 3, (arg1, arg2, arg3)) +#define STAP_PROBE4(provider, name, arg1, arg2, arg3, arg4) \ + _SDT_PROBE(provider, name, 4, (arg1, arg2, arg3, arg4)) +#define STAP_PROBE5(provider, name, arg1, arg2, arg3, arg4, arg5) \ + _SDT_PROBE(provider, name, 5, (arg1, arg2, arg3, arg4, arg5)) +#define STAP_PROBE6(provider, name, arg1, arg2, arg3, arg4, arg5, arg6) \ + _SDT_PROBE(provider, name, 6, (arg1, arg2, arg3, arg4, arg5, arg6)) +#define STAP_PROBE7(provider, name, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \ + _SDT_PROBE(provider, name, 7, (arg1, arg2, arg3, arg4, arg5, arg6, arg7)) +#define STAP_PROBE8(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8) \ + _SDT_PROBE(provider, name, 8, (arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8)) +#define STAP_PROBE9(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9)\ + _SDT_PROBE(provider, name, 9, (arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9)) +#define STAP_PROBE10(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10) \ + _SDT_PROBE(provider, name, 10, \ + (arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10)) +#define STAP_PROBE11(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11) \ + _SDT_PROBE(provider, name, 11, \ + (arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11)) +#define STAP_PROBE12(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11,arg12) \ + _SDT_PROBE(provider, name, 12, \ + (arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11,arg12)) + +/* This STAP_PROBEV macro can be used in variadic scenarios, where the + number of probe arguments is not known until compile time. Since + variadic macro support may vary with compiler options, you must + pre-#define SDT_USE_VARIADIC to enable this type of probe. + + The trick to count __VA_ARGS__ was inspired by this post by + Laurent Deniau <laurent.deniau@cern.ch>: + http://groups.google.com/group/comp.std.c/msg/346fc464319b1ee5 + + Note that our _SDT_NARG is called with an extra 0 arg that's not + counted, so we don't have to worry about the behavior of macros + called without any arguments. */ + +#define _SDT_NARG(...) __SDT_NARG(__VA_ARGS__, 12,11,10,9,8,7,6,5,4,3,2,1,0) +#define __SDT_NARG(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12, N, ...) N +#ifdef SDT_USE_VARIADIC +#define _SDT_PROBE_N(provider, name, N, ...) \ + _SDT_PROBE(provider, name, N, (__VA_ARGS__)) +#define STAP_PROBEV(provider, name, ...) \ + _SDT_PROBE_N(provider, name, _SDT_NARG(0, ##__VA_ARGS__), ##__VA_ARGS__) +#endif + +/* These macros are for use in asm statements. You must compile + with -std=gnu99 or -std=c99 to use the STAP_PROBE_ASM macro. + + The STAP_PROBE_ASM macro generates a quoted string to be used in the + template portion of the asm statement, concatenated with strings that + contain the actual assembly code around the probe site. + + For example: + + asm ("before\n" + STAP_PROBE_ASM(provider, fooprobe, %eax 4(%esi)) + "after"); + + emits the assembly code for "before\nafter", with a probe in between. + The probe arguments are the %eax register, and the value of the memory + word located 4 bytes past the address in the %esi register. Note that + because this is a simple asm, not a GNU C extended asm statement, these + % characters do not need to be doubled to generate literal %reg names. + + In a GNU C extended asm statement, the probe arguments can be specified + using the macro STAP_PROBE_ASM_TEMPLATE(n) for n arguments. The paired + macro STAP_PROBE_ASM_OPERANDS gives the C values of these probe arguments, + and appears in the input operand list of the asm statement. For example: + + asm ("someinsn %0,%1\n" // %0 is output operand, %1 is input operand + STAP_PROBE_ASM(provider, fooprobe, STAP_PROBE_ASM_TEMPLATE(3)) + "otherinsn %[namedarg]" + : "r" (outvar) + : "g" (some_value), [namedarg] "i" (1234), + STAP_PROBE_ASM_OPERANDS(3, some_value, some_ptr->field, 1234)); + + This is just like writing: + + STAP_PROBE3(provider, fooprobe, some_value, some_ptr->field, 1234)); + + but the probe site is right between "someinsn" and "otherinsn". + + The probe arguments in STAP_PROBE_ASM can be given as assembly + operands instead, even inside a GNU C extended asm statement. + Note that these can use operand templates like %0 or %[name], + and likewise they must write %%reg for a literal operand of %reg. */ + +#define _SDT_ASM_BODY_1(p,n,...) _SDT_ASM_BODY(p,n,_SDT_ASM_SUBSTR,(__VA_ARGS__)) +#define _SDT_ASM_BODY_2(p,n,...) _SDT_ASM_BODY(p,n,/*_SDT_ASM_STRING */,__VA_ARGS__) +#define _SDT_ASM_BODY_N2(p,n,no,...) _SDT_ASM_BODY_ ## no(p,n,__VA_ARGS__) +#define _SDT_ASM_BODY_N1(p,n,no,...) _SDT_ASM_BODY_N2(p,n,no,__VA_ARGS__) +#define _SDT_ASM_BODY_N(p,n,...) _SDT_ASM_BODY_N1(p,n,_SDT_NARG(0, __VA_ARGS__),__VA_ARGS__) + +#if __STDC_VERSION__ >= 199901L +# define STAP_PROBE_ASM(provider, name, ...) \ + _SDT_ASM_BODY_N(provider, name, __VA_ARGS__) \ + _SDT_ASM_BASE +# define STAP_PROBE_ASM_OPERANDS(n, ...) _SDT_ASM_OPERANDS_##n(__VA_ARGS__) +#else +# define STAP_PROBE_ASM(provider, name, args) \ + _SDT_ASM_BODY(provider, name, /* _SDT_ASM_STRING */, (args)) \ + _SDT_ASM_BASE +#endif +#define STAP_PROBE_ASM_TEMPLATE(n) _SDT_ASM_TEMPLATE_##n,"use _SDT_ASM_TEMPLATE_" + + +/* DTrace compatible macro names. */ +#define DTRACE_PROBE(provider,probe) \ + STAP_PROBE(provider,probe) +#define DTRACE_PROBE1(provider,probe,parm1) \ + STAP_PROBE1(provider,probe,parm1) +#define DTRACE_PROBE2(provider,probe,parm1,parm2) \ + STAP_PROBE2(provider,probe,parm1,parm2) +#define DTRACE_PROBE3(provider,probe,parm1,parm2,parm3) \ + STAP_PROBE3(provider,probe,parm1,parm2,parm3) +#define DTRACE_PROBE4(provider,probe,parm1,parm2,parm3,parm4) \ + STAP_PROBE4(provider,probe,parm1,parm2,parm3,parm4) +#define DTRACE_PROBE5(provider,probe,parm1,parm2,parm3,parm4,parm5) \ + STAP_PROBE5(provider,probe,parm1,parm2,parm3,parm4,parm5) +#define DTRACE_PROBE6(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6) \ + STAP_PROBE6(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6) +#define DTRACE_PROBE7(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7) \ + STAP_PROBE7(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7) +#define DTRACE_PROBE8(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8) \ + STAP_PROBE8(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8) +#define DTRACE_PROBE9(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9) \ + STAP_PROBE9(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9) +#define DTRACE_PROBE10(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10) \ + STAP_PROBE10(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10) +#define DTRACE_PROBE11(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10,parm11) \ + STAP_PROBE11(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10,parm11) +#define DTRACE_PROBE12(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10,parm11,parm12) \ + STAP_PROBE12(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10,parm11,parm12) + + +#endif /* sys/sdt.h */ diff --git a/tools/testing/selftests/bpf/test_bpftool_synctypes.py b/tools/testing/selftests/bpf/test_bpftool_synctypes.py index 6bf21e47882a..c0e7acd698ed 100755 --- a/tools/testing/selftests/bpf/test_bpftool_synctypes.py +++ b/tools/testing/selftests/bpf/test_bpftool_synctypes.py @@ -180,7 +180,7 @@ class FileExtractor(object): @enum_name: name of the enum to parse """ start_marker = re.compile(f'enum {enum_name} {{\n') - pattern = re.compile('^\s*(BPF_\w+),?$') + pattern = re.compile('^\s*(BPF_\w+),?(\s+/\*.*\*/)?$') end_marker = re.compile('^};') parser = BlockParser(self.reader) parser.search_block(start_marker) diff --git a/tools/testing/selftests/bpf/test_cgroup_storage.c b/tools/testing/selftests/bpf/test_cgroup_storage.c index d6a1be4d8020..2ffa08198d1c 100644 --- a/tools/testing/selftests/bpf/test_cgroup_storage.c +++ b/tools/testing/selftests/bpf/test_cgroup_storage.c @@ -7,6 +7,7 @@ #include <sys/sysinfo.h> #include "bpf_rlimit.h" +#include "bpf_util.h" #include "cgroup_helpers.h" #include "testing_helpers.h" @@ -44,7 +45,7 @@ int main(int argc, char **argv) unsigned long long *percpu_value; int cpu, nproc; - nproc = get_nprocs_conf(); + nproc = bpf_num_possible_cpus(); percpu_value = malloc(sizeof(*percpu_value) * nproc); if (!percpu_value) { printf("Not enough memory for per-cpu area (%d cpus)\n", nproc); diff --git a/tools/testing/selftests/bpf/test_offload.py b/tools/testing/selftests/bpf/test_offload.py index edaffd43da83..6cd6ef9fc20b 100755 --- a/tools/testing/selftests/bpf/test_offload.py +++ b/tools/testing/selftests/bpf/test_offload.py @@ -184,7 +184,7 @@ def bpftool_prog_list(expected=None, ns=""): def bpftool_map_list(expected=None, ns=""): _, maps = bpftool("map show", JSON=True, ns=ns, fail=True) # Remove the base maps - maps = [m for m in maps if m not in base_maps and m.get('name') not in base_map_names] + maps = [m for m in maps if m not in base_maps and m.get('name') and m.get('name') not in base_map_names] if expected is not None: if len(maps) != expected: fail(True, "%d BPF maps loaded, expected %d" % diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index 2ecb73a65206..0a4b45d7b515 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -761,8 +761,10 @@ int cd_flavor_subdir(const char *exec_name) const char *flavor = strrchr(exec_name, '/'); if (!flavor) - return 0; - flavor++; + flavor = exec_name; + else + flavor++; + flavor = strrchr(flavor, '-'); if (!flavor) return 0; diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h index 93c1ff705533..eec4c7385b14 100644 --- a/tools/testing/selftests/bpf/test_progs.h +++ b/tools/testing/selftests/bpf/test_progs.h @@ -332,6 +332,8 @@ int trigger_module_test_write(int write_sz); #define SYS_NANOSLEEP_KPROBE_NAME "__x64_sys_nanosleep" #elif defined(__s390x__) #define SYS_NANOSLEEP_KPROBE_NAME "__s390x_sys_nanosleep" +#elif defined(__aarch64__) +#define SYS_NANOSLEEP_KPROBE_NAME "__arm64_sys_nanosleep" #else #define SYS_NANOSLEEP_KPROBE_NAME "sys_nanosleep" #endif diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c index 795b6798ccee..87867f7a78c3 100644 --- a/tools/testing/selftests/bpf/testing_helpers.c +++ b/tools/testing/selftests/bpf/testing_helpers.c @@ -60,7 +60,7 @@ int parse_num_list(const char *s, bool **num_set, int *num_set_len) set[i] = true; } - if (!set) + if (!set || parsing_end) return -EINVAL; *num_set = set; diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index 3d6217e3aff7..9c4be2cdb21a 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -25,15 +25,12 @@ static int ksym_cmp(const void *p1, const void *p2) int load_kallsyms(void) { - FILE *f = fopen("/proc/kallsyms", "r"); + FILE *f; char func[256], buf[256]; char symbol; void *addr; int i = 0; - if (!f) - return -ENOENT; - /* * This is called/used from multiplace places, * load symbols just once. @@ -41,6 +38,10 @@ int load_kallsyms(void) if (sym_cnt) return 0; + f = fopen("/proc/kallsyms", "r"); + if (!f) + return -ENOENT; + while (fgets(buf, sizeof(buf), f)) { if (sscanf(buf, "%p %c %s", &addr, &symbol, func) != 3) break; diff --git a/tools/testing/selftests/bpf/urandom_read.c b/tools/testing/selftests/bpf/urandom_read.c index db781052758d..e92644d0fa75 100644 --- a/tools/testing/selftests/bpf/urandom_read.c +++ b/tools/testing/selftests/bpf/urandom_read.c @@ -1,32 +1,85 @@ +#include <stdbool.h> #include <stdio.h> #include <unistd.h> +#include <errno.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <stdlib.h> +#include <signal.h> + +#define _SDT_HAS_SEMAPHORES 1 +#include "sdt.h" + +#define SEC(name) __attribute__((section(name), used)) #define BUF_SIZE 256 +/* defined in urandom_read_aux.c */ +void urand_read_without_sema(int iter_num, int iter_cnt, int read_sz); +/* these are coming from urandom_read_lib{1,2}.c */ +void urandlib_read_with_sema(int iter_num, int iter_cnt, int read_sz); +void urandlib_read_without_sema(int iter_num, int iter_cnt, int read_sz); + +unsigned short urand_read_with_sema_semaphore SEC(".probes"); + static __attribute__((noinline)) void urandom_read(int fd, int count) { - char buf[BUF_SIZE]; - int i; + char buf[BUF_SIZE]; + int i; + + for (i = 0; i < count; ++i) { + read(fd, buf, BUF_SIZE); + + /* trigger USDTs defined in executable itself */ + urand_read_without_sema(i, count, BUF_SIZE); + STAP_PROBE3(urand, read_with_sema, i, count, BUF_SIZE); - for (i = 0; i < count; ++i) - read(fd, buf, BUF_SIZE); + /* trigger USDTs defined in shared lib */ + urandlib_read_without_sema(i, count, BUF_SIZE); + urandlib_read_with_sema(i, count, BUF_SIZE); + } +} + +static volatile bool parent_ready; + +static void handle_sigpipe(int sig) +{ + parent_ready = true; } int main(int argc, char *argv[]) { int fd = open("/dev/urandom", O_RDONLY); int count = 4; + bool report_pid = false; if (fd < 0) return 1; - if (argc == 2) + if (argc >= 2) count = atoi(argv[1]); + if (argc >= 3) { + report_pid = true; + /* install SIGPIPE handler to catch when parent closes their + * end of the pipe (on the other side of our stdout) + */ + signal(SIGPIPE, handle_sigpipe); + } + + /* report PID and wait for parent process to send us "signal" by + * closing stdout + */ + if (report_pid) { + while (!parent_ready) { + fprintf(stdout, "%d\n", getpid()); + fflush(stdout); + } + /* at this point stdout is closed, parent process knows our + * PID and is ready to trace us + */ + } urandom_read(fd, count); diff --git a/tools/testing/selftests/bpf/urandom_read_aux.c b/tools/testing/selftests/bpf/urandom_read_aux.c new file mode 100644 index 000000000000..6132edcfea74 --- /dev/null +++ b/tools/testing/selftests/bpf/urandom_read_aux.c @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ +#include "sdt.h" + +void urand_read_without_sema(int iter_num, int iter_cnt, int read_sz) +{ + /* semaphore-less USDT */ + STAP_PROBE3(urand, read_without_sema, iter_num, iter_cnt, read_sz); +} diff --git a/tools/testing/selftests/bpf/urandom_read_lib1.c b/tools/testing/selftests/bpf/urandom_read_lib1.c new file mode 100644 index 000000000000..86186e24b740 --- /dev/null +++ b/tools/testing/selftests/bpf/urandom_read_lib1.c @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ +#define _SDT_HAS_SEMAPHORES 1 +#include "sdt.h" + +#define SEC(name) __attribute__((section(name), used)) + +unsigned short urandlib_read_with_sema_semaphore SEC(".probes"); + +void urandlib_read_with_sema(int iter_num, int iter_cnt, int read_sz) +{ + STAP_PROBE3(urandlib, read_with_sema, iter_num, iter_cnt, read_sz); +} diff --git a/tools/testing/selftests/bpf/urandom_read_lib2.c b/tools/testing/selftests/bpf/urandom_read_lib2.c new file mode 100644 index 000000000000..9d401ad9838f --- /dev/null +++ b/tools/testing/selftests/bpf/urandom_read_lib2.c @@ -0,0 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ +#include "sdt.h" + +void urandlib_read_without_sema(int iter_num, int iter_cnt, int read_sz) +{ + STAP_PROBE3(urandlib, read_without_sema, iter_num, iter_cnt, read_sz); +} |