diff options
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/bpf/bpf.c | 34 | ||||
| -rw-r--r-- | tools/lib/bpf/bpf_helpers.h | 7 | ||||
| -rw-r--r-- | tools/lib/bpf/bpf_tracing.h | 23 | ||||
| -rw-r--r-- | tools/lib/bpf/btf.c | 9 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 322 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.h | 82 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf_internal.h | 9 | ||||
| -rw-r--r-- | tools/lib/bpf/relo_core.c | 104 | ||||
| -rw-r--r-- | tools/lib/bpf/relo_core.h | 6 | ||||
| -rw-r--r-- | tools/lib/bpf/usdt.c | 191 |
10 files changed, 655 insertions, 132 deletions
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index cf27251adb92..a9d292c106c2 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -817,7 +817,7 @@ int bpf_link_create(int prog_fd, int target_fd, { __u32 target_btf_id, iter_info_len; union bpf_attr attr; - int fd; + int fd, err; if (!OPTS_VALID(opts, bpf_link_create_opts)) return libbpf_err(-EINVAL); @@ -870,7 +870,37 @@ int bpf_link_create(int prog_fd, int target_fd, } proceed: fd = sys_bpf_fd(BPF_LINK_CREATE, &attr, sizeof(attr)); - return libbpf_err_errno(fd); + if (fd >= 0) + return fd; + /* we'll get EINVAL if LINK_CREATE doesn't support attaching fentry + * and other similar programs + */ + err = -errno; + if (err != -EINVAL) + return libbpf_err(err); + + /* if user used features not supported by + * BPF_RAW_TRACEPOINT_OPEN command, then just give up immediately + */ + if (attr.link_create.target_fd || attr.link_create.target_btf_id) + return libbpf_err(err); + if (!OPTS_ZEROED(opts, sz)) + return libbpf_err(err); + + /* otherwise, for few select kinds of programs that can be + * attached using BPF_RAW_TRACEPOINT_OPEN command, try that as + * a fallback for older kernels + */ + switch (attach_type) { + case BPF_TRACE_RAW_TP: + case BPF_LSM_MAC: + case BPF_TRACE_FENTRY: + case BPF_TRACE_FEXIT: + case BPF_MODIFY_RETURN: + return bpf_raw_tracepoint_open(NULL, prog_fd); + default: + return libbpf_err(err); + } } int bpf_link_detach(int link_fd) diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h index 44df982d2a5c..5de3eb267125 100644 --- a/tools/lib/bpf/bpf_helpers.h +++ b/tools/lib/bpf/bpf_helpers.h @@ -149,6 +149,13 @@ enum libbpf_tristate { #define __kconfig __attribute__((section(".kconfig"))) #define __ksym __attribute__((section(".ksyms"))) +#if __has_attribute(btf_type_tag) +#define __kptr __attribute__((btf_type_tag("kptr"))) +#define __kptr_ref __attribute__((btf_type_tag("kptr_ref"))) +#else +#define __kptr +#define __kptr_ref +#endif #ifndef ___bpf_concat #define ___bpf_concat(a, b) a ## b diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h index e3a8c947e89f..01ce121c302d 100644 --- a/tools/lib/bpf/bpf_tracing.h +++ b/tools/lib/bpf/bpf_tracing.h @@ -27,6 +27,9 @@ #elif defined(__TARGET_ARCH_riscv) #define bpf_target_riscv #define bpf_target_defined +#elif defined(__TARGET_ARCH_arc) + #define bpf_target_arc + #define bpf_target_defined #else /* Fall back to what the compiler says */ @@ -54,6 +57,9 @@ #elif defined(__riscv) && __riscv_xlen == 64 #define bpf_target_riscv #define bpf_target_defined +#elif defined(__arc__) + #define bpf_target_arc + #define bpf_target_defined #endif /* no compiler target */ #endif @@ -233,6 +239,23 @@ struct pt_regs___arm64 { /* riscv does not select ARCH_HAS_SYSCALL_WRAPPER. */ #define PT_REGS_SYSCALL_REGS(ctx) ctx +#elif defined(bpf_target_arc) + +/* arc provides struct user_pt_regs instead of struct pt_regs to userspace */ +#define __PT_REGS_CAST(x) ((const struct user_regs_struct *)(x)) +#define __PT_PARM1_REG scratch.r0 +#define __PT_PARM2_REG scratch.r1 +#define __PT_PARM3_REG scratch.r2 +#define __PT_PARM4_REG scratch.r3 +#define __PT_PARM5_REG scratch.r4 +#define __PT_RET_REG scratch.blink +#define __PT_FP_REG __unsupported__ +#define __PT_RC_REG scratch.r0 +#define __PT_SP_REG scratch.sp +#define __PT_IP_REG scratch.ret +/* arc does not select ARCH_HAS_SYSCALL_WRAPPER. */ +#define PT_REGS_SYSCALL_REGS(ctx) ctx + #endif #if defined(bpf_target_defined) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index d124e9e533f0..bb1e06eb1eca 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -2626,6 +2626,7 @@ static int btf_ext_setup_info(struct btf_ext *btf_ext, const struct btf_ext_info_sec *sinfo; struct btf_ext_info *ext_info; __u32 info_left, record_size; + size_t sec_cnt = 0; /* The start of the info sec (including the __u32 record_size). */ void *info; @@ -2689,8 +2690,7 @@ static int btf_ext_setup_info(struct btf_ext *btf_ext, return -EINVAL; } - total_record_size = sec_hdrlen + - (__u64)num_records * record_size; + total_record_size = sec_hdrlen + (__u64)num_records * record_size; if (info_left < total_record_size) { pr_debug("%s section has incorrect num_records in .BTF.ext\n", ext_sec->desc); @@ -2699,12 +2699,14 @@ static int btf_ext_setup_info(struct btf_ext *btf_ext, info_left -= total_record_size; sinfo = (void *)sinfo + total_record_size; + sec_cnt++; } ext_info = ext_sec->ext_info; ext_info->len = ext_sec->len - sizeof(__u32); ext_info->rec_size = record_size; ext_info->info = info + sizeof(__u32); + ext_info->sec_cnt = sec_cnt; return 0; } @@ -2788,6 +2790,9 @@ void btf_ext__free(struct btf_ext *btf_ext) { if (IS_ERR_OR_NULL(btf_ext)) return; + free(btf_ext->func_info.sec_idxs); + free(btf_ext->line_info.sec_idxs); + free(btf_ext->core_relo_info.sec_idxs); free(btf_ext->data); free(btf_ext); } diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 465b7c0996f1..73a5192defb3 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -302,7 +302,7 @@ struct bpf_program { void *priv; bpf_program_clear_priv_t clear_priv; - bool load; + bool autoload; bool mark_btf_static; enum bpf_prog_type type; enum bpf_attach_type expected_attach_type; @@ -672,7 +672,18 @@ bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog, prog->insns_cnt = prog->sec_insn_cnt; prog->type = BPF_PROG_TYPE_UNSPEC; - prog->load = true; + + /* libbpf's convention for SEC("?abc...") is that it's just like + * SEC("abc...") but the corresponding bpf_program starts out with + * autoload set to false. + */ + if (sec_name[0] == '?') { + prog->autoload = false; + /* from now on forget there was ? in section name */ + sec_name++; + } else { + prog->autoload = true; + } prog->instances.fds = NULL; prog->instances.nr = -1; @@ -1222,10 +1233,8 @@ static void bpf_object__elf_finish(struct bpf_object *obj) if (!obj->efile.elf) return; - if (obj->efile.elf) { - elf_end(obj->efile.elf); - obj->efile.elf = NULL; - } + elf_end(obj->efile.elf); + obj->efile.elf = NULL; obj->efile.symbols = NULL; obj->efile.st_ops_data = NULL; @@ -2756,6 +2765,9 @@ static int bpf_object__init_btf(struct bpf_object *obj, btf__set_pointer_size(obj->btf, 8); } if (btf_ext_data) { + struct btf_ext_info *ext_segs[3]; + int seg_num, sec_num; + if (!obj->btf) { pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n", BTF_EXT_ELF_SEC, BTF_ELF_SEC); @@ -2769,6 +2781,43 @@ static int bpf_object__init_btf(struct bpf_object *obj, obj->btf_ext = NULL; goto out; } + + /* setup .BTF.ext to ELF section mapping */ + ext_segs[0] = &obj->btf_ext->func_info; + ext_segs[1] = &obj->btf_ext->line_info; + ext_segs[2] = &obj->btf_ext->core_relo_info; + for (seg_num = 0; seg_num < ARRAY_SIZE(ext_segs); seg_num++) { + struct btf_ext_info *seg = ext_segs[seg_num]; + const struct btf_ext_info_sec *sec; + const char *sec_name; + Elf_Scn *scn; + + if (seg->sec_cnt == 0) + continue; + + seg->sec_idxs = calloc(seg->sec_cnt, sizeof(*seg->sec_idxs)); + if (!seg->sec_idxs) { + err = -ENOMEM; + goto out; + } + + sec_num = 0; + for_each_btf_ext_sec(seg, sec) { + /* preventively increment index to avoid doing + * this before every continue below + */ + sec_num++; + + sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off); + if (str_is_empty(sec_name)) + continue; + scn = elf_sec_by_name(obj, sec_name); + if (!scn) + continue; + + seg->sec_idxs[sec_num - 1] = elf_ndxscn(scn); + } + } } out: if (err && libbpf_needs_btf(obj)) { @@ -2927,7 +2976,7 @@ static bool obj_needs_vmlinux_btf(const struct bpf_object *obj) } bpf_object__for_each_program(prog, obj) { - if (!prog->load) + if (!prog->autoload) continue; if (prog_needs_vmlinux_btf(prog)) return true; @@ -4594,7 +4643,7 @@ static int probe_kern_probe_read_kernel(void) }; int fd, insn_cnt = ARRAY_SIZE(insns); - fd = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, "GPL", insns, insn_cnt, NULL); + fd = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL", insns, insn_cnt, NULL); return probe_fd(fd); } @@ -5577,6 +5626,22 @@ static int record_relo_core(struct bpf_program *prog, return 0; } +static const struct bpf_core_relo *find_relo_core(struct bpf_program *prog, int insn_idx) +{ + struct reloc_desc *relo; + int i; + + for (i = 0; i < prog->nr_reloc; i++) { + relo = &prog->reloc_desc[i]; + if (relo->type != RELO_CORE || relo->insn_idx != insn_idx) + continue; + + return relo->core_relo; + } + + return NULL; +} + static int bpf_core_resolve_relo(struct bpf_program *prog, const struct bpf_core_relo *relo, int relo_idx, @@ -5633,7 +5698,7 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) struct bpf_program *prog; struct bpf_insn *insn; const char *sec_name; - int i, err = 0, insn_idx, sec_idx; + int i, err = 0, insn_idx, sec_idx, sec_num; if (obj->btf_ext->core_relo_info.len == 0) return 0; @@ -5654,32 +5719,18 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) } seg = &obj->btf_ext->core_relo_info; + sec_num = 0; for_each_btf_ext_sec(seg, sec) { + sec_idx = seg->sec_idxs[sec_num]; + sec_num++; + sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off); if (str_is_empty(sec_name)) { err = -EINVAL; goto out; } - /* bpf_object's ELF is gone by now so it's not easy to find - * section index by section name, but we can find *any* - * bpf_program within desired section name and use it's - * prog->sec_idx to do a proper search by section index and - * instruction offset - */ - prog = NULL; - for (i = 0; i < obj->nr_programs; i++) { - prog = &obj->programs[i]; - if (strcmp(prog->sec_name, sec_name) == 0) - break; - } - if (!prog) { - pr_warn("sec '%s': failed to find a BPF program\n", sec_name); - return -ENOENT; - } - sec_idx = prog->sec_idx; - pr_debug("sec '%s': found %d CO-RE relocations\n", - sec_name, sec->num_info); + pr_debug("sec '%s': found %d CO-RE relocations\n", sec_name, sec->num_info); for_each_btf_ext_rec(seg, sec, i, rec) { if (rec->insn_off % BPF_INSN_SZ) @@ -5702,7 +5753,7 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) /* no need to apply CO-RE relocation if the program is * not going to be loaded */ - if (!prog->load) + if (!prog->autoload) continue; /* adjust insn_idx from section frame of reference to the local @@ -5714,16 +5765,16 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) return -EINVAL; insn = &prog->insns[insn_idx]; - if (prog->obj->gen_loader) { - err = record_relo_core(prog, rec, insn_idx); - if (err) { - pr_warn("prog '%s': relo #%d: failed to record relocation: %d\n", - prog->name, i, err); - goto out; - } - continue; + err = record_relo_core(prog, rec, insn_idx); + if (err) { + pr_warn("prog '%s': relo #%d: failed to record relocation: %d\n", + prog->name, i, err); + goto out; } + if (prog->obj->gen_loader) + continue; + err = bpf_core_resolve_relo(prog, rec, i, obj->btf, cand_cache, &targ_res); if (err) { pr_warn("prog '%s': relo #%d: failed to relocate: %d\n", @@ -5863,14 +5914,13 @@ static int adjust_prog_btf_ext_info(const struct bpf_object *obj, void *rec, *rec_end, *new_prog_info; const struct btf_ext_info_sec *sec; size_t old_sz, new_sz; - const char *sec_name; - int i, off_adj; + int i, sec_num, sec_idx, off_adj; + sec_num = 0; for_each_btf_ext_sec(ext_info, sec) { - sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off); - if (!sec_name) - return -EINVAL; - if (strcmp(sec_name, prog->sec_name) != 0) + sec_idx = ext_info->sec_idxs[sec_num]; + sec_num++; + if (prog->sec_idx != sec_idx) continue; for_each_btf_ext_rec(ext_info, sec, i, rec) { @@ -6265,7 +6315,6 @@ bpf_object__relocate_calls(struct bpf_object *obj, struct bpf_program *prog) if (err) return err; - return 0; } @@ -6326,8 +6375,7 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) err); return err; } - if (obj->gen_loader) - bpf_object__sort_relos(obj); + bpf_object__sort_relos(obj); } /* Before relocating calls pre-process relocations and mark @@ -6363,7 +6411,7 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) */ if (prog_is_subprog(obj, prog)) continue; - if (!prog->load) + if (!prog->autoload) continue; err = bpf_object__relocate_calls(obj, prog); @@ -6378,7 +6426,7 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) prog = &obj->programs[i]; if (prog_is_subprog(obj, prog)) continue; - if (!prog->load) + if (!prog->autoload) continue; err = bpf_object__relocate_data(obj, prog); if (err) { @@ -6387,8 +6435,7 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) return err; } } - if (!obj->gen_loader) - bpf_object__free_relocs(obj); + return 0; } @@ -6665,6 +6712,8 @@ static int libbpf_prepare_prog_load(struct bpf_program *prog, return 0; } +static void fixup_verifier_log(struct bpf_program *prog, char *buf, size_t buf_sz); + static int bpf_object_load_prog_instance(struct bpf_object *obj, struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, const char *license, __u32 kern_version, @@ -6811,6 +6860,10 @@ retry_load: goto retry_load; ret = -errno; + + /* post-process verifier log to improve error descriptions */ + fixup_verifier_log(prog, log_buf, log_buf_size); + cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); pr_warn("prog '%s': BPF program load failed: %s\n", prog->name, cp); pr_perm_msg(ret); @@ -6819,10 +6872,6 @@ retry_load: pr_warn("prog '%s': -- BEGIN PROG LOAD LOG --\n%s-- END PROG LOAD LOG --\n", prog->name, log_buf); } - if (insns_cnt >= BPF_MAXINSNS) { - pr_warn("prog '%s': program too large (%d insns), at most %d insns\n", - prog->name, insns_cnt, BPF_MAXINSNS); - } out: if (own_log_buf) @@ -6830,6 +6879,128 @@ out: return ret; } +static char *find_prev_line(char *buf, char *cur) +{ + char *p; + + if (cur == buf) /* end of a log buf */ + return NULL; + + p = cur - 1; + while (p - 1 >= buf && *(p - 1) != '\n') + p--; + + return p; +} + +static void patch_log(char *buf, size_t buf_sz, size_t log_sz, + char *orig, size_t orig_sz, const char *patch) +{ + /* size of the remaining log content to the right from the to-be-replaced part */ + size_t rem_sz = (buf + log_sz) - (orig + orig_sz); + size_t patch_sz = strlen(patch); + + if (patch_sz != orig_sz) { + /* If patch line(s) are longer than original piece of verifier log, + * shift log contents by (patch_sz - orig_sz) bytes to the right + * starting from after to-be-replaced part of the log. + * + * If patch line(s) are shorter than original piece of verifier log, + * shift log contents by (orig_sz - patch_sz) bytes to the left + * starting from after to-be-replaced part of the log + * + * We need to be careful about not overflowing available + * buf_sz capacity. If that's the case, we'll truncate the end + * of the original log, as necessary. + */ + if (patch_sz > orig_sz) { + if (orig + patch_sz >= buf + buf_sz) { + /* patch is big enough to cover remaining space completely */ + patch_sz -= (orig + patch_sz) - (buf + buf_sz) + 1; + rem_sz = 0; + } else if (patch_sz - orig_sz > buf_sz - log_sz) { + /* patch causes part of remaining log to be truncated */ + rem_sz -= (patch_sz - orig_sz) - (buf_sz - log_sz); + } + } + /* shift remaining log to the right by calculated amount */ + memmove(orig + patch_sz, orig + orig_sz, rem_sz); + } + + memcpy(orig, patch, patch_sz); +} + +static void fixup_log_failed_core_relo(struct bpf_program *prog, + char *buf, size_t buf_sz, size_t log_sz, + char *line1, char *line2, char *line3) +{ + /* Expected log for failed and not properly guarded CO-RE relocation: + * line1 -> 123: (85) call unknown#195896080 + * line2 -> invalid func unknown#195896080 + * line3 -> <anything else or end of buffer> + * + * "123" is the index of the instruction that was poisoned. We extract + * instruction index to find corresponding CO-RE relocation and + * replace this part of the log with more relevant information about + * failed CO-RE relocation. + */ + const struct bpf_core_relo *relo; + struct bpf_core_spec spec; + char patch[512], spec_buf[256]; + int insn_idx, err; + + if (sscanf(line1, "%d: (%*d) call unknown#195896080\n", &insn_idx) != 1) + return; + + relo = find_relo_core(prog, insn_idx); + if (!relo) + return; + + err = bpf_core_parse_spec(prog->name, prog->obj->btf, relo, &spec); + if (err) + return; + + bpf_core_format_spec(spec_buf, sizeof(spec_buf), &spec); + snprintf(patch, sizeof(patch), + "%d: <invalid CO-RE relocation>\n" + "failed to resolve CO-RE relocation %s\n", + insn_idx, spec_buf); + + patch_log(buf, buf_sz, log_sz, line1, line3 - line1, patch); +} + +static void fixup_verifier_log(struct bpf_program *prog, char *buf, size_t buf_sz) +{ + /* look for familiar error patterns in last N lines of the log */ + const size_t max_last_line_cnt = 10; + char *prev_line, *cur_line, *next_line; + size_t log_sz; + int i; + + if (!buf) + return; + + log_sz = strlen(buf) + 1; + next_line = buf + log_sz - 1; + + for (i = 0; i < max_last_line_cnt; i++, next_line = cur_line) { + cur_line = find_prev_line(buf, next_line); + if (!cur_line) + return; + + /* failed CO-RE relocation case */ + if (str_has_pfx(cur_line, "invalid func unknown#195896080\n")) { + prev_line = find_prev_line(buf, cur_line); + if (!prev_line) + continue; + + fixup_log_failed_core_relo(prog, buf, buf_sz, log_sz, + prev_line, cur_line, next_line); + return; + } + } +} + static int bpf_program_record_relos(struct bpf_program *prog) { struct bpf_object *obj = prog->obj; @@ -6975,7 +7146,7 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level) prog = &obj->programs[i]; if (prog_is_subprog(obj, prog)) continue; - if (!prog->load) { + if (!prog->autoload) { pr_debug("prog '%s': skipped loading\n", prog->name); continue; } @@ -6984,8 +7155,8 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level) if (err) return err; } - if (obj->gen_loader) - bpf_object__free_relocs(obj); + + bpf_object__free_relocs(obj); return 0; } @@ -7005,8 +7176,8 @@ static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object continue; } - bpf_program__set_type(prog, prog->sec_def->prog_type); - bpf_program__set_expected_attach_type(prog, prog->sec_def->expected_attach_type); + prog->type = prog->sec_def->prog_type; + prog->expected_attach_type = prog->sec_def->expected_attach_type; #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wdeprecated-declarations" @@ -8455,7 +8626,7 @@ const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy) bool bpf_program__autoload(const struct bpf_program *prog) { - return prog->load; + return prog->autoload; } int bpf_program__set_autoload(struct bpf_program *prog, bool autoload) @@ -8463,7 +8634,7 @@ int bpf_program__set_autoload(struct bpf_program *prog, bool autoload) if (prog->obj->loaded) return libbpf_err(-EINVAL); - prog->load = autoload; + prog->autoload = autoload; return 0; } @@ -8551,9 +8722,13 @@ enum bpf_prog_type bpf_program__type(const struct bpf_program *prog) return prog->type; } -void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type) +int bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type) { + if (prog->obj->loaded) + return libbpf_err(-EBUSY); + prog->type = type; + return 0; } static bool bpf_program__is_type(const struct bpf_program *prog, @@ -8567,8 +8742,7 @@ int bpf_program__set_##NAME(struct bpf_program *prog) \ { \ if (!prog) \ return libbpf_err(-EINVAL); \ - bpf_program__set_type(prog, TYPE); \ - return 0; \ + return bpf_program__set_type(prog, TYPE); \ } \ \ bool bpf_program__is_##NAME(const struct bpf_program *prog) \ @@ -8598,10 +8772,14 @@ enum bpf_attach_type bpf_program__expected_attach_type(const struct bpf_program return prog->expected_attach_type; } -void bpf_program__set_expected_attach_type(struct bpf_program *prog, +int bpf_program__set_expected_attach_type(struct bpf_program *prog, enum bpf_attach_type type) { + if (prog->obj->loaded) + return libbpf_err(-EBUSY); + prog->expected_attach_type = type; + return 0; } __u32 bpf_program__flags(const struct bpf_program *prog) @@ -9671,9 +9849,8 @@ static int bpf_prog_load_xattr2(const struct bpf_prog_load_attr *attr, * bpf_object__open guessed */ if (attr->prog_type != BPF_PROG_TYPE_UNSPEC) { - bpf_program__set_type(prog, attr->prog_type); - bpf_program__set_expected_attach_type(prog, - attach_type); + prog->type = attr->prog_type; + prog->expected_attach_type = attach_type; } if (bpf_program__type(prog) == BPF_PROG_TYPE_UNSPEC) { /* @@ -10982,7 +11159,7 @@ struct bpf_link *bpf_program__attach_usdt(const struct bpf_program *prog, char resolved_path[512]; struct bpf_object *obj = prog->obj; struct bpf_link *link; - long usdt_cookie; + __u64 usdt_cookie; int err; if (!OPTS_VALID(opts, bpf_uprobe_opts)) @@ -11245,7 +11422,8 @@ static struct bpf_link *bpf_program__attach_btf_id(const struct bpf_program *pro return libbpf_err_ptr(-ENOMEM); link->detach = &bpf_link__detach_fd; - pfd = bpf_raw_tracepoint_open(NULL, prog_fd); + /* libbpf is smart enough to redirect to BPF_RAW_TRACEPOINT_OPEN on old kernels */ + pfd = bpf_link_create(prog_fd, 0, bpf_program__expected_attach_type(prog), NULL); if (pfd < 0) { pfd = -errno; free(link); @@ -11254,7 +11432,7 @@ static struct bpf_link *bpf_program__attach_btf_id(const struct bpf_program *pro return libbpf_err_ptr(pfd); } link->fd = pfd; - return (struct bpf_link *)link; + return link; } struct bpf_link *bpf_program__attach_trace(const struct bpf_program *prog) @@ -12665,7 +12843,7 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s) struct bpf_program *prog = *s->progs[i].prog; struct bpf_link **link = s->progs[i].link; - if (!prog->load) + if (!prog->autoload) continue; /* auto-attaching not supported for this program */ diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 63d66f1adf1a..cdbfee60ea3e 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -378,7 +378,31 @@ struct bpf_link; LIBBPF_API struct bpf_link *bpf_link__open(const char *path); LIBBPF_API int bpf_link__fd(const struct bpf_link *link); LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link); +/** + * @brief **bpf_link__pin()** pins the BPF link to a file + * in the BPF FS specified by a path. This increments the links + * reference count, allowing it to stay loaded after the process + * which loaded it has exited. + * + * @param link BPF link to pin, must already be loaded + * @param path file path in a BPF file system + * @return 0, on success; negative error code, otherwise + */ + LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path); + +/** + * @brief **bpf_link__unpin()** unpins the BPF link from a file + * in the BPFFS specified by a path. This decrements the links + * reference count. + * + * The file pinning the BPF link can also be unlinked by a different + * process in which case this function will return an error. + * + * @param prog BPF program to unpin + * @param path file path to the pin in a BPF file system + * @return 0, on success; negative error code, otherwise + */ LIBBPF_API int bpf_link__unpin(struct bpf_link *link); LIBBPF_API int bpf_link__update_program(struct bpf_link *link, struct bpf_program *prog); @@ -386,6 +410,22 @@ LIBBPF_API void bpf_link__disconnect(struct bpf_link *link); LIBBPF_API int bpf_link__detach(struct bpf_link *link); LIBBPF_API int bpf_link__destroy(struct bpf_link *link); +/** + * @brief **bpf_program__attach()** is a generic function for attaching + * a BPF program based on auto-detection of program type, attach type, + * and extra paremeters, where applicable. + * + * @param prog BPF program to attach + * @return Reference to the newly created BPF link; or NULL is returned on error, + * error code is stored in errno + * + * This is supported for: + * - kprobe/kretprobe (depends on SEC() definition) + * - uprobe/uretprobe (depends on SEC() definition) + * - tracepoint + * - raw tracepoint + * - tracing programs (typed raw TP/fentry/fexit/fmod_ret) + */ LIBBPF_API struct bpf_link * bpf_program__attach(const struct bpf_program *prog); @@ -686,12 +726,37 @@ LIBBPF_DEPRECATED_SINCE(0, 8, "use bpf_program__set_type() instead") LIBBPF_API int bpf_program__set_sk_lookup(struct bpf_program *prog); LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog); -LIBBPF_API void bpf_program__set_type(struct bpf_program *prog, - enum bpf_prog_type type); + +/** + * @brief **bpf_program__set_type()** sets the program + * type of the passed BPF program. + * @param prog BPF program to set the program type for + * @param type program type to set the BPF map to have + * @return error code; or 0 if no error. An error occurs + * if the object is already loaded. + * + * This must be called before the BPF object is loaded, + * otherwise it has no effect and an error is returned. + */ +LIBBPF_API int bpf_program__set_type(struct bpf_program *prog, + enum bpf_prog_type type); LIBBPF_API enum bpf_attach_type bpf_program__expected_attach_type(const struct bpf_program *prog); -LIBBPF_API void + +/** + * @brief **bpf_program__set_expected_attach_type()** sets the + * attach type of the passed BPF program. This is used for + * auto-detection of attachment when programs are loaded. + * @param prog BPF program to set the attach type for + * @param type attach type to set the BPF map to have + * @return error code; or 0 if no error. An error occurs + * if the object is already loaded. + * + * This must be called before the BPF object is loaded, + * otherwise it has no effect and an error is returned. + */ +LIBBPF_API int bpf_program__set_expected_attach_type(struct bpf_program *prog, enum bpf_attach_type type); @@ -707,6 +772,17 @@ LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_le LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size); LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size); +/** + * @brief **bpf_program__set_attach_target()** sets BTF-based attach target + * for supported BPF program types: + * - BTF-aware raw tracepoints (tp_btf); + * - fentry/fexit/fmod_ret; + * - lsm; + * - freplace. + * @param prog BPF program to set the attach type for + * @param type attach type to set the BPF map to have + * @return error code; or 0 if no error occurred. + */ LIBBPF_API int bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd, const char *attach_func_name); diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index 080272421f6c..4abdbe2fea9d 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -376,6 +376,13 @@ struct btf_ext_info { void *info; __u32 rec_size; __u32 len; + /* optional (maintained internally by libbpf) mapping between .BTF.ext + * section and corresponding ELF section. This is used to join + * information like CO-RE relocation records with corresponding BPF + * programs defined in ELF sections + */ + __u32 *sec_idxs; + int sec_cnt; }; #define for_each_btf_ext_sec(seg, sec) \ @@ -571,6 +578,6 @@ 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); + __u64 usdt_cookie); #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ diff --git a/tools/lib/bpf/relo_core.c b/tools/lib/bpf/relo_core.c index f946f23eab20..ba4453dfd1ed 100644 --- a/tools/lib/bpf/relo_core.c +++ b/tools/lib/bpf/relo_core.c @@ -178,29 +178,28 @@ static bool core_relo_is_enumval_based(enum bpf_core_relo_kind kind) * Enum value-based relocations (ENUMVAL_EXISTS/ENUMVAL_VALUE) use access * string to specify enumerator's value index that need to be relocated. */ -static int bpf_core_parse_spec(const char *prog_name, const struct btf *btf, - __u32 type_id, - const char *spec_str, - enum bpf_core_relo_kind relo_kind, - struct bpf_core_spec *spec) +int bpf_core_parse_spec(const char *prog_name, const struct btf *btf, + const struct bpf_core_relo *relo, + struct bpf_core_spec *spec) { int access_idx, parsed_len, i; struct bpf_core_accessor *acc; const struct btf_type *t; - const char *name; + const char *name, *spec_str; __u32 id; __s64 sz; + spec_str = btf__name_by_offset(btf, relo->access_str_off); if (str_is_empty(spec_str) || *spec_str == ':') return -EINVAL; memset(spec, 0, sizeof(*spec)); spec->btf = btf; - spec->root_type_id = type_id; - spec->relo_kind = relo_kind; + spec->root_type_id = relo->type_id; + spec->relo_kind = relo->kind; /* type-based relocations don't have a field access string */ - if (core_relo_is_type_based(relo_kind)) { + if (core_relo_is_type_based(relo->kind)) { if (strcmp(spec_str, "0")) return -EINVAL; return 0; @@ -221,7 +220,7 @@ static int bpf_core_parse_spec(const char *prog_name, const struct btf *btf, if (spec->raw_len == 0) return -EINVAL; - t = skip_mods_and_typedefs(btf, type_id, &id); + t = skip_mods_and_typedefs(btf, relo->type_id, &id); if (!t) return -EINVAL; @@ -231,7 +230,7 @@ static int bpf_core_parse_spec(const char *prog_name, const struct btf *btf, acc->idx = access_idx; spec->len++; - if (core_relo_is_enumval_based(relo_kind)) { + if (core_relo_is_enumval_based(relo->kind)) { if (!btf_is_enum(t) || spec->raw_len > 1 || access_idx >= btf_vlen(t)) return -EINVAL; @@ -240,7 +239,7 @@ static int bpf_core_parse_spec(const char *prog_name, const struct btf *btf, return 0; } - if (!core_relo_is_field_based(relo_kind)) + if (!core_relo_is_field_based(relo->kind)) return -EINVAL; sz = btf__resolve_size(btf, id); @@ -301,7 +300,7 @@ static int bpf_core_parse_spec(const char *prog_name, const struct btf *btf, spec->bit_offset += access_idx * sz * 8; } else { pr_warn("prog '%s': relo for [%u] %s (at idx %d) captures type [%d] of unexpected kind %s\n", - prog_name, type_id, spec_str, i, id, btf_kind_str(t)); + prog_name, relo->type_id, spec_str, i, id, btf_kind_str(t)); return -EINVAL; } } @@ -1055,51 +1054,66 @@ poison: * [<type-id>] (<type-name>) + <raw-spec> => <offset>@<spec>, * where <spec> is a C-syntax view of recorded field access, e.g.: x.a[3].b */ -static void bpf_core_dump_spec(const char *prog_name, int level, const struct bpf_core_spec *spec) +int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *spec) { const struct btf_type *t; const struct btf_enum *e; const char *s; __u32 type_id; - int i; + int i, len = 0; + +#define append_buf(fmt, args...) \ + ({ \ + int r; \ + r = snprintf(buf, buf_sz, fmt, ##args); \ + len += r; \ + if (r >= buf_sz) \ + r = buf_sz; \ + buf += r; \ + buf_sz -= r; \ + }) type_id = spec->root_type_id; t = btf_type_by_id(spec->btf, type_id); s = btf__name_by_offset(spec->btf, t->name_off); - libbpf_print(level, "[%u] %s %s", type_id, btf_kind_str(t), str_is_empty(s) ? "<anon>" : s); + append_buf("<%s> [%u] %s %s", + core_relo_kind_str(spec->relo_kind), + type_id, btf_kind_str(t), str_is_empty(s) ? "<anon>" : s); if (core_relo_is_type_based(spec->relo_kind)) - return; + return len; if (core_relo_is_enumval_based(spec->relo_kind)) { t = skip_mods_and_typedefs(spec->btf, type_id, NULL); e = btf_enum(t) + spec->raw_spec[0]; s = btf__name_by_offset(spec->btf, e->name_off); - libbpf_print(level, "::%s = %u", s, e->val); - return; + append_buf("::%s = %u", s, e->val); + return len; } if (core_relo_is_field_based(spec->relo_kind)) { for (i = 0; i < spec->len; i++) { if (spec->spec[i].name) - libbpf_print(level, ".%s", spec->spec[i].name); + append_buf(".%s", spec->spec[i].name); else if (i > 0 || spec->spec[i].idx > 0) - libbpf_print(level, "[%u]", spec->spec[i].idx); + append_buf("[%u]", spec->spec[i].idx); } - libbpf_print(level, " ("); + append_buf(" ("); for (i = 0; i < spec->raw_len; i++) - libbpf_print(level, "%s%d", i == 0 ? "" : ":", spec->raw_spec[i]); + append_buf("%s%d", i == 0 ? "" : ":", spec->raw_spec[i]); if (spec->bit_offset % 8) - libbpf_print(level, " @ offset %u.%u)", - spec->bit_offset / 8, spec->bit_offset % 8); + append_buf(" @ offset %u.%u)", spec->bit_offset / 8, spec->bit_offset % 8); else - libbpf_print(level, " @ offset %u)", spec->bit_offset / 8); - return; + append_buf(" @ offset %u)", spec->bit_offset / 8); + return len; } + + return len; +#undef append_buf } /* @@ -1167,7 +1181,7 @@ int bpf_core_calc_relo_insn(const char *prog_name, const struct btf_type *local_type; const char *local_name; __u32 local_id; - const char *spec_str; + char spec_buf[256]; int i, j, err; local_id = relo->type_id; @@ -1176,24 +1190,20 @@ int bpf_core_calc_relo_insn(const char *prog_name, if (!local_name) return -EINVAL; - spec_str = btf__name_by_offset(local_btf, relo->access_str_off); - if (str_is_empty(spec_str)) - return -EINVAL; - - err = bpf_core_parse_spec(prog_name, local_btf, local_id, spec_str, - relo->kind, local_spec); + err = bpf_core_parse_spec(prog_name, local_btf, relo, local_spec); if (err) { + const char *spec_str; + + spec_str = btf__name_by_offset(local_btf, relo->access_str_off); pr_warn("prog '%s': relo #%d: parsing [%d] %s %s + %s failed: %d\n", prog_name, relo_idx, local_id, btf_kind_str(local_type), str_is_empty(local_name) ? "<anon>" : local_name, - spec_str, err); + spec_str ?: "<?>", err); return -EINVAL; } - pr_debug("prog '%s': relo #%d: kind <%s> (%d), spec is ", prog_name, - relo_idx, core_relo_kind_str(relo->kind), relo->kind); - bpf_core_dump_spec(prog_name, LIBBPF_DEBUG, local_spec); - libbpf_print(LIBBPF_DEBUG, "\n"); + bpf_core_format_spec(spec_buf, sizeof(spec_buf), local_spec); + pr_debug("prog '%s': relo #%d: %s\n", prog_name, relo_idx, spec_buf); /* TYPE_ID_LOCAL relo is special and doesn't need candidate search */ if (relo->kind == BPF_CORE_TYPE_ID_LOCAL) { @@ -1207,7 +1217,7 @@ int bpf_core_calc_relo_insn(const char *prog_name, } /* libbpf doesn't support candidate search for anonymous types */ - if (str_is_empty(spec_str)) { + if (str_is_empty(local_name)) { pr_warn("prog '%s': relo #%d: <%s> (%d) relocation doesn't support anonymous types\n", prog_name, relo_idx, core_relo_kind_str(relo->kind), relo->kind); return -EOPNOTSUPP; @@ -1217,17 +1227,15 @@ int bpf_core_calc_relo_insn(const char *prog_name, err = bpf_core_spec_match(local_spec, cands->cands[i].btf, cands->cands[i].id, cand_spec); if (err < 0) { - pr_warn("prog '%s': relo #%d: error matching candidate #%d ", - prog_name, relo_idx, i); - bpf_core_dump_spec(prog_name, LIBBPF_WARN, cand_spec); - libbpf_print(LIBBPF_WARN, ": %d\n", err); + bpf_core_format_spec(spec_buf, sizeof(spec_buf), cand_spec); + pr_warn("prog '%s': relo #%d: error matching candidate #%d %s: %d\n ", + prog_name, relo_idx, i, spec_buf, err); return err; } - pr_debug("prog '%s': relo #%d: %s candidate #%d ", prog_name, - relo_idx, err == 0 ? "non-matching" : "matching", i); - bpf_core_dump_spec(prog_name, LIBBPF_DEBUG, cand_spec); - libbpf_print(LIBBPF_DEBUG, "\n"); + bpf_core_format_spec(spec_buf, sizeof(spec_buf), cand_spec); + pr_debug("prog '%s': relo #%d: %s candidate #%d %s\n", prog_name, + relo_idx, err == 0 ? "non-matching" : "matching", i, spec_buf); if (err == 0) continue; diff --git a/tools/lib/bpf/relo_core.h b/tools/lib/bpf/relo_core.h index a28bf3711ce2..073039d8ca4f 100644 --- a/tools/lib/bpf/relo_core.h +++ b/tools/lib/bpf/relo_core.h @@ -84,4 +84,10 @@ int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn, int insn_idx, const struct bpf_core_relo *relo, int relo_idx, const struct bpf_core_relo_res *res); +int bpf_core_parse_spec(const char *prog_name, const struct btf *btf, + const struct bpf_core_relo *relo, + struct bpf_core_spec *spec); + +int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *spec); + #endif diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c index acf2d99a9e77..f1c9339cfbbc 100644 --- a/tools/lib/bpf/usdt.c +++ b/tools/lib/bpf/usdt.c @@ -10,6 +10,11 @@ #include <linux/ptrace.h> #include <linux/kernel.h> +/* s8 will be marked as poison while it's a reg of riscv */ +#if defined(__riscv) +#define rv_s8 s8 +#endif + #include "bpf.h" #include "libbpf.h" #include "libbpf_common.h" @@ -557,10 +562,10 @@ 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 parse_usdt_spec(struct usdt_spec *spec, const struct usdt_note *note, __u64 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, + const char *usdt_provider, const char *usdt_name, __u64 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; @@ -939,7 +944,7 @@ static int allocate_spec_id(struct usdt_manager *man, struct hashmap *specs_hash 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) + __u64 usdt_cookie) { int i, fd, err, spec_map_fd, ip_map_fd; LIBBPF_OPTS(bpf_uprobe_opts, opts); @@ -1141,7 +1146,7 @@ static int parse_usdt_note(Elf *elf, const char *path, long base_addr, 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) +static int parse_usdt_spec(struct usdt_spec *spec, const struct usdt_note *note, __u64 usdt_cookie) { const char *s; int len; @@ -1324,6 +1329,184 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec return len; } +#elif defined(__aarch64__) + +static int calc_pt_regs_off(const char *reg_name) +{ + int reg_num; + + if (sscanf(reg_name, "x%d", ®_num) == 1) { + if (reg_num >= 0 && reg_num < 31) + return offsetof(struct user_pt_regs, regs[reg_num]); + } else if (strcmp(reg_name, "sp") == 0) { + return offsetof(struct user_pt_regs, sp); + } + 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 @ \[ %m[a-z0-9], %ld ] %n", &arg_sz, ®_name, &off, &len) == 3) { + /* Memory dereference case, e.g., -4@[sp, 96] */ + 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 @ \[ %m[a-z0-9] ] %n", &arg_sz, ®_name, &len) == 2) { + /* Memory dereference case, e.g., -4@[sp] */ + arg->arg_type = USDT_ARG_REG_DEREF; + 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@5 */ + arg->arg_type = USDT_ARG_CONST; + arg->val_off = off; + arg->reg_off = 0; + } else if (sscanf(arg_str, " %d @ %m[a-z0-9] %n", &arg_sz, ®_name, &len) == 2) { + /* Register read case, e.g., -8@x4 */ + 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 { + 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(__riscv) + +static int calc_pt_regs_off(const char *reg_name) +{ + static struct { + const char *name; + size_t pt_regs_off; + } reg_map[] = { + { "ra", offsetof(struct user_regs_struct, ra) }, + { "sp", offsetof(struct user_regs_struct, sp) }, + { "gp", offsetof(struct user_regs_struct, gp) }, + { "tp", offsetof(struct user_regs_struct, tp) }, + { "a0", offsetof(struct user_regs_struct, a0) }, + { "a1", offsetof(struct user_regs_struct, a1) }, + { "a2", offsetof(struct user_regs_struct, a2) }, + { "a3", offsetof(struct user_regs_struct, a3) }, + { "a4", offsetof(struct user_regs_struct, a4) }, + { "a5", offsetof(struct user_regs_struct, a5) }, + { "a6", offsetof(struct user_regs_struct, a6) }, + { "a7", offsetof(struct user_regs_struct, a7) }, + { "s0", offsetof(struct user_regs_struct, s0) }, + { "s1", offsetof(struct user_regs_struct, s1) }, + { "s2", offsetof(struct user_regs_struct, s2) }, + { "s3", offsetof(struct user_regs_struct, s3) }, + { "s4", offsetof(struct user_regs_struct, s4) }, + { "s5", offsetof(struct user_regs_struct, s5) }, + { "s6", offsetof(struct user_regs_struct, s6) }, + { "s7", offsetof(struct user_regs_struct, s7) }, + { "s8", offsetof(struct user_regs_struct, rv_s8) }, + { "s9", offsetof(struct user_regs_struct, s9) }, + { "s10", offsetof(struct user_regs_struct, s10) }, + { "s11", offsetof(struct user_regs_struct, s11) }, + { "t0", offsetof(struct user_regs_struct, t0) }, + { "t1", offsetof(struct user_regs_struct, t1) }, + { "t2", offsetof(struct user_regs_struct, t2) }, + { "t3", offsetof(struct user_regs_struct, t3) }, + { "t4", offsetof(struct user_regs_struct, t4) }, + { "t5", offsetof(struct user_regs_struct, t5) }, + { "t6", offsetof(struct user_regs_struct, t6) }, + }; + int i; + + for (i = 0; i < ARRAY_SIZE(reg_map); i++) { + if (strcmp(reg_name, reg_map[i].name) == 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[a-z0-9] ) %n", &arg_sz, &off, ®_name, &len) == 3) { + /* Memory dereference case, e.g., -8@-88(s0) */ + 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 @ %ld %n", &arg_sz, &off, &len) == 2) { + /* Constant value case, e.g., 4@5 */ + arg->arg_type = USDT_ARG_CONST; + arg->val_off = off; + arg->reg_off = 0; + } else if (sscanf(arg_str, " %d @ %m[a-z0-9] %n", &arg_sz, ®_name, &len) == 2) { + /* Register read case, e.g., -8@a1 */ + 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 { + 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) |