static int probe_point_inline_cb(Dwarf_Die *in_die, void *data) { struct probe_finder *pf = data; struct perf_probe_point *pp = &pf->pev->point; Dwarf_Addr addr; int ret; if (pp->lazy_line) ret = find_probe_point_lazy(in_die, pf); else { if (dwarf_entrypc(in_die, &addr) != 0) { pr_warning("Failed to get entry address of %s.\n", dwarf_diename(in_die)); return -ENOENT; } pf->addr = addr; pf->addr += pp->offset; pr_debug("found inline addr: 0x%jx\n", (uintmax_t)pf->addr); ret = call_probe_finder(in_die, pf); } return ret; }
static int probe_point_inline_cb(Dwarf_Die *in_die, void *data) { struct dwarf_callback_param *param = data; struct probe_finder *pf = param->data; struct perf_probe_point *pp = &pf->pev->point; Dwarf_Addr addr; if (pp->lazy_line) param->retval = find_probe_point_lazy(in_die, pf); else { /* Get probe address */ if (dwarf_entrypc(in_die, &addr) != 0) { pr_warning("Failed to get entry address of %s.\n", dwarf_diename(in_die)); param->retval = -ENOENT; return DWARF_CB_ABORT; } pf->addr = addr; pf->addr += pp->offset; pr_debug("found inline addr: 0x%jx\n", (uintmax_t)pf->addr); param->retval = call_probe_finder(in_die, pf); if (param->retval < 0) return DWARF_CB_ABORT; } return DWARF_CB_OK; }
static int probe_point_lazy_walker(const char *fname, int lineno, Dwarf_Addr addr, void *data) { struct probe_finder *pf = data; Dwarf_Die *sc_die, die_mem; int ret; if (!line_list__has_line(&pf->lcache, lineno) || strtailcmp(fname, pf->fname) != 0) return 0; pr_debug("Probe line found: line:%d addr:0x%llx\n", lineno, (unsigned long long)addr); pf->addr = addr; pf->lno = lineno; sc_die = find_best_scope(pf, &die_mem); if (!sc_die) { pr_warning("Failed to find scope of probe point.\n"); return -ENOENT; } ret = call_probe_finder(sc_die, pf); return ret < 0 ? ret : 0; }
static int probe_point_line_walker(const char *fname, int lineno, Dwarf_Addr addr, void *data) { struct probe_finder *pf = data; int ret; if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0) return 0; pf->addr = addr; ret = call_probe_finder(NULL, pf); /* Continue if no error, because the line will be in inline function */ return ret < 0 ? ret : 0; }
static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) { struct dwarf_callback_param *param = data; struct probe_finder *pf = param->data; struct perf_probe_point *pp = &pf->pev->point; Dwarf_Attribute attr; if (dwarf_tag(sp_die) != DW_TAG_subprogram || !die_compare_name(sp_die, pp->function) || dwarf_attr(sp_die, DW_AT_declaration, &attr)) return DWARF_CB_OK; if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die))) return DWARF_CB_OK; pf->fname = dwarf_decl_file(sp_die); if (pp->line) { dwarf_decl_line(sp_die, &pf->lno); pf->lno += pp->line; param->retval = find_probe_point_by_line(pf); } else if (!dwarf_func_inline(sp_die)) { if (pp->lazy_line) param->retval = find_probe_point_lazy(sp_die, pf); else { if (dwarf_entrypc(sp_die, &pf->addr) != 0) { pr_warning("Failed to get entry address of " "%s.\n", dwarf_diename(sp_die)); param->retval = -ENOENT; return DWARF_CB_ABORT; } pf->addr += pp->offset; param->retval = call_probe_finder(sp_die, pf); } } else param->retval = die_walk_instances(sp_die, probe_point_inline_cb, (void *)pf); return DWARF_CB_ABORT; }
/* Search function from function name */ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) { struct dwarf_callback_param *param = data; struct probe_finder *pf = param->data; struct perf_probe_point *pp = &pf->pev->point; /* Check tag and diename */ if (dwarf_tag(sp_die) != DW_TAG_subprogram || !die_compare_name(sp_die, pp->function)) return DWARF_CB_OK; /* Check declared file */ if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die))) return DWARF_CB_OK; pf->fname = dwarf_decl_file(sp_die); if (pp->line) { /* Function relative line */ dwarf_decl_line(sp_die, &pf->lno); pf->lno += pp->line; param->retval = find_probe_point_by_line(pf); } else if (!dwarf_func_inline(sp_die)) { /* Real function */ if (pp->lazy_line) param->retval = find_probe_point_lazy(sp_die, pf); else { if (dwarf_entrypc(sp_die, &pf->addr) != 0) { pr_warning("Failed to get entry address of " "%s.\n", dwarf_diename(sp_die)); param->retval = -ENOENT; return DWARF_CB_ABORT; } pf->addr += pp->offset; /* TODO: Check the address in this function */ param->retval = call_probe_finder(sp_die, pf); } } else /* Inlined function: search instances */ param->retval = die_walk_instances(sp_die, probe_point_inline_cb, (void *)pf); return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */ }
static int probe_point_lazy_walker(const char *fname, int lineno, Dwarf_Addr addr, void *data) { struct probe_finder *pf = data; int ret; if (!line_list__has_line(&pf->lcache, lineno) || strtailcmp(fname, pf->fname) != 0) return 0; pr_debug("Probe line found: line:%d addr:0x%llx\n", lineno, (unsigned long long)addr); pf->addr = addr; ret = call_probe_finder(NULL, pf); /* * Continue if no error, because the lazy pattern will match * to other lines */ return ret < 0 ? ret : 0; }
static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem) { struct find_scope_param fsp = { .function = pf->pev->point.function, .file = pf->fname, .line = pf->lno, .diff = INT_MAX, .die_mem = die_mem, .found = false, }; cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp); return fsp.found ? die_mem : NULL; } static int probe_point_line_walker(const char *fname, int lineno, Dwarf_Addr addr, void *data) { struct probe_finder *pf = data; Dwarf_Die *sc_die, die_mem; int ret; if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0) return 0; pf->addr = addr; sc_die = find_best_scope(pf, &die_mem); if (!sc_die) { pr_warning("Failed to find scope of probe point.\n"); return -ENOENT; } ret = call_probe_finder(sc_die, pf); return ret < 0 ? ret : 0; } static int find_probe_point_by_line(struct probe_finder *pf) { return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf); } static int find_lazy_match_lines(struct list_head *head, const char *fname, const char *pat) { FILE *fp; char *line = NULL; size_t line_len; ssize_t len; int count = 0, linenum = 1; fp = fopen(fname, "r"); if (!fp) { pr_warning("Failed to open %s: %s\n", fname, strerror(errno)); return -errno; } while ((len = getline(&line, &line_len, fp)) > 0) { if (line[len - 1] == '\n') line[len - 1] = '\0'; if (strlazymatch(line, pat)) { line_list__add_line(head, linenum); count++; } linenum++; } if (ferror(fp)) count = -errno; free(line); fclose(fp); if (count == 0) pr_debug("No matched lines found in %s.\n", fname); return count; }
/* Search function from function name */ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) { struct dwarf_callback_param *param = data; struct probe_finder *pf = param->data; struct perf_probe_point *pp = &pf->pev->point; /* Check tag and diename */ if (dwarf_tag(sp_die) != DW_TAG_subprogram || !die_compare_name(sp_die, pp->function)) return DWARF_CB_OK; pf->fname = dwarf_decl_file(sp_die); if (pp->line) { /* Function relative line */ dwarf_decl_line(sp_die, &pf->lno); pf->lno += pp->line; param->retval = find_probe_point_by_line(pf); } else if (!dwarf_func_inline(sp_die)) { /* Real function */ if (pp->lazy_line) param->retval = find_probe_point_lazy(sp_die, pf); else { if (dwarf_entrypc(sp_die, &pf->addr) != 0) { pr_warning("Failed to get entry address of " "%s.\n", dwarf_diename(sp_die)); param->retval = -ENOENT; return DWARF_CB_ABORT; } pf->addr += pp->offset; /* TODO: Check the address in this function */ param->retval = call_probe_finder(sp_die, pf); } } else { struct dwarf_callback_param _param = {.data = (void *)pf, .retval = 0}; /* Inlined function: search instances */ dwarf_func_inline_instances(sp_die, probe_point_inline_cb, &_param); param->retval = _param.retval; } return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */ } static int find_probe_point_by_func(struct probe_finder *pf) { struct dwarf_callback_param _param = {.data = (void *)pf, .retval = 0}; dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0); return _param.retval; } /* Find probe points from debuginfo */ static int find_probes(int fd, struct probe_finder *pf) { struct perf_probe_point *pp = &pf->pev->point; Dwarf_Off off, noff; size_t cuhl; Dwarf_Die *diep; Dwarf *dbg = NULL; Dwfl *dwfl; Dwarf_Addr bias; /* Currently ignored */ int ret = 0; dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias); if (!dbg) { pr_warning("No debug information found in the vmlinux - " "please rebuild with CONFIG_DEBUG_INFO=y.\n"); return -EBADF; } #if _ELFUTILS_PREREQ(0, 142) /* Get the call frame information from this dwarf */ pf->cfi = dwarf_getcfi(dbg); #endif off = 0; line_list__init(&pf->lcache); /* Loop on CUs (Compilation Unit) */ while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL)) { /* Get the DIE(Debugging Information Entry) of this CU */ diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die); if (!diep) continue; /* Check if target file is included. */ if (pp->file) pf->fname = cu_find_realpath(&pf->cu_die, pp->file); else pf->fname = NULL; if (!pp->file || pf->fname) { if (pp->function) ret = find_probe_point_by_func(pf); else if (pp->lazy_line) ret = find_probe_point_lazy(NULL, pf); else { pf->lno = pp->line; ret = find_probe_point_by_line(pf); } if (ret < 0) break; } off = noff; } line_list__free(&pf->lcache); if (dwfl) dwfl_end(dwfl); return ret; } /* Add a found probe point into trace event list */ static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf) { struct trace_event_finder *tf = container_of(pf, struct trace_event_finder, pf); struct probe_trace_event *tev; int ret, i; /* Check number of tevs */ if (tf->ntevs == tf->max_tevs) { pr_warning("Too many( > %d) probe point found.\n", tf->max_tevs); return -ERANGE; } tev = &tf->tevs[tf->ntevs++]; ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe, &tev->point); if (ret < 0) return ret; pr_debug("Probe point found: %s+%lu\n", tev->point.symbol, tev->point.offset); /* Find each argument */ tev->nargs = pf->pev->nargs; tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs); if (tev->args == NULL) return -ENOMEM; for (i = 0; i < pf->pev->nargs; i++) { pf->pvar = &pf->pev->args[i]; pf->tvar = &tev->args[i]; ret = find_variable(sp_die, pf); if (ret != 0) return ret; } return 0; } /* Find probe_trace_events specified by perf_probe_event from debuginfo */ int find_probe_trace_events(int fd, struct perf_probe_event *pev, struct probe_trace_event **tevs, int max_tevs) { struct trace_event_finder tf = { .pf = {.pev = pev, .callback = add_probe_trace_event}, .max_tevs = max_tevs}; int ret; /* Allocate result tevs array */ *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs); if (*tevs == NULL) return -ENOMEM; tf.tevs = *tevs; tf.ntevs = 0; ret = find_probes(fd, &tf.pf); if (ret < 0) { free(*tevs); *tevs = NULL; return ret; } return (ret < 0) ? ret : tf.ntevs; } #define MAX_VAR_LEN 64 /* Collect available variables in this scope */ static int collect_variables_cb(Dwarf_Die *die_mem, void *data) { struct available_var_finder *af = data; struct variable_list *vl; char buf[MAX_VAR_LEN]; int tag, ret; vl = &af->vls[af->nvls - 1]; tag = dwarf_tag(die_mem); if (tag == DW_TAG_formal_parameter || tag == DW_TAG_variable) { ret = convert_variable_location(die_mem, af->pf.addr, af->pf.fb_ops, NULL); if (ret == 0) { ret = die_get_varname(die_mem, buf, MAX_VAR_LEN); pr_debug2("Add new var: %s\n", buf); if (ret > 0) strlist__add(vl->vars, buf); } } if (af->child && dwarf_haspc(die_mem, af->pf.addr)) return DIE_FIND_CB_CONTINUE; else return DIE_FIND_CB_SIBLING; } /* Add a found vars into available variables list */ static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf) { struct available_var_finder *af = container_of(pf, struct available_var_finder, pf); struct variable_list *vl; Dwarf_Die die_mem, *scopes = NULL; int ret, nscopes; /* Check number of tevs */ if (af->nvls == af->max_vls) { pr_warning("Too many( > %d) probe point found.\n", af->max_vls); return -ERANGE; } vl = &af->vls[af->nvls++]; ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe, &vl->point); if (ret < 0) return ret; pr_debug("Probe point found: %s+%lu\n", vl->point.symbol, vl->point.offset); /* Find local variables */ vl->vars = strlist__new(true, NULL); if (vl->vars == NULL) return -ENOMEM; af->child = true; die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem); /* Find external variables */ if (!af->externs) goto out; /* Don't need to search child DIE for externs. */ af->child = false; nscopes = dwarf_getscopes_die(sp_die, &scopes); while (nscopes-- > 1) die_find_child(&scopes[nscopes], collect_variables_cb, (void *)af, &die_mem); if (scopes) free(scopes); out: if (strlist__empty(vl->vars)) { strlist__delete(vl->vars); vl->vars = NULL; } return ret; } /* Find available variables at given probe point */ int find_available_vars_at(int fd, struct perf_probe_event *pev, struct variable_list **vls, int max_vls, bool externs) { struct available_var_finder af = { .pf = {.pev = pev, .callback = add_available_vars}, .max_vls = max_vls, .externs = externs}; int ret; /* Allocate result vls array */ *vls = zalloc(sizeof(struct variable_list) * max_vls); if (*vls == NULL) return -ENOMEM; af.vls = *vls; af.nvls = 0; ret = find_probes(fd, &af.pf); if (ret < 0) { /* Free vlist for error */ while (af.nvls--) { if (af.vls[af.nvls].point.symbol) free(af.vls[af.nvls].point.symbol); if (af.vls[af.nvls].vars) strlist__delete(af.vls[af.nvls].vars); } free(af.vls); *vls = NULL; return ret; } return (ret < 0) ? ret : af.nvls; }