| /* |
| * probe-finder.c : C expression to kprobe event converter |
| * |
| * Written by Masami Hiramatsu <mhiramat@redhat.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| * |
| */ |
| |
| #include <sys/utsname.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <fcntl.h> |
| #include <errno.h> |
| #include <stdio.h> |
| #include <unistd.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <stdarg.h> |
| #include <dwarf-regs.h> |
| |
| #include <linux/bitops.h> |
| #include "event.h" |
| #include "dso.h" |
| #include "debug.h" |
| #include "intlist.h" |
| #include "util.h" |
| #include "symbol.h" |
| #include "probe-finder.h" |
| |
| /* Kprobe tracer basic type is up to u64 */ |
| #define MAX_BASIC_TYPE_BITS 64 |
| |
| /* Dwarf FL wrappers */ |
| static char *debuginfo_path; /* Currently dummy */ |
| |
| static const Dwfl_Callbacks offline_callbacks = { |
| .find_debuginfo = dwfl_standard_find_debuginfo, |
| .debuginfo_path = &debuginfo_path, |
| |
| .section_address = dwfl_offline_section_address, |
| |
| /* We use this table for core files too. */ |
| .find_elf = dwfl_build_id_find_elf, |
| }; |
| |
| /* Get a Dwarf from offline image */ |
| static int debuginfo__init_offline_dwarf(struct debuginfo *dbg, |
| const char *path) |
| { |
| int fd; |
| |
| fd = open(path, O_RDONLY); |
| if (fd < 0) |
| return fd; |
| |
| dbg->dwfl = dwfl_begin(&offline_callbacks); |
| if (!dbg->dwfl) |
| goto error; |
| |
| dwfl_report_begin(dbg->dwfl); |
| dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd); |
| if (!dbg->mod) |
| goto error; |
| |
| dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias); |
| if (!dbg->dbg) |
| goto error; |
| |
| dwfl_report_end(dbg->dwfl, NULL, NULL); |
| |
| return 0; |
| error: |
| if (dbg->dwfl) |
| dwfl_end(dbg->dwfl); |
| else |
| close(fd); |
| memset(dbg, 0, sizeof(*dbg)); |
| |
| return -ENOENT; |
| } |
| |
| static struct debuginfo *__debuginfo__new(const char *path) |
| { |
| struct debuginfo *dbg = zalloc(sizeof(*dbg)); |
| if (!dbg) |
| return NULL; |
| |
| if (debuginfo__init_offline_dwarf(dbg, path) < 0) |
| zfree(&dbg); |
| if (dbg) |
| pr_debug("Open Debuginfo file: %s\n", path); |
| return dbg; |
| } |
| |
| enum dso_binary_type distro_dwarf_types[] = { |
| DSO_BINARY_TYPE__FEDORA_DEBUGINFO, |
| DSO_BINARY_TYPE__UBUNTU_DEBUGINFO, |
| DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO, |
| DSO_BINARY_TYPE__BUILDID_DEBUGINFO, |
| DSO_BINARY_TYPE__NOT_FOUND, |
| }; |
| |
| struct debuginfo *debuginfo__new(const char *path) |
| { |
| enum dso_binary_type *type; |
| char buf[PATH_MAX], nil = '\0'; |
| struct dso *dso; |
| struct debuginfo *dinfo = NULL; |
| |
| /* Try to open distro debuginfo files */ |
| dso = dso__new(path); |
| if (!dso) |
| goto out; |
| |
| for (type = distro_dwarf_types; |
| !dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND; |
| type++) { |
| if (dso__read_binary_type_filename(dso, *type, &nil, |
| buf, PATH_MAX) < 0) |
| continue; |
| dinfo = __debuginfo__new(buf); |
| } |
| dso__put(dso); |
| |
| out: |
| /* if failed to open all distro debuginfo, open given binary */ |
| return dinfo ? : __debuginfo__new(path); |
| } |
| |
| void debuginfo__delete(struct debuginfo *dbg) |
| { |
| if (dbg) { |
| if (dbg->dwfl) |
| dwfl_end(dbg->dwfl); |
| free(dbg); |
| } |
| } |
| |
| /* |
| * Probe finder related functions |
| */ |
| |
| static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs) |
| { |
| struct probe_trace_arg_ref *ref; |
| ref = zalloc(sizeof(struct probe_trace_arg_ref)); |
| if (ref != NULL) |
| ref->offset = offs; |
| return ref; |
| } |
| |
| /* |
| * Convert a location into trace_arg. |
| * If tvar == NULL, this just checks variable can be converted. |
| * If fentry == true and vr_die is a parameter, do huristic search |
| * for the location fuzzed by function entry mcount. |
| */ |
| static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr, |
| Dwarf_Op *fb_ops, Dwarf_Die *sp_die, |
| struct probe_trace_arg *tvar) |
| { |
| Dwarf_Attribute attr; |
| Dwarf_Addr tmp = 0; |
| Dwarf_Op *op; |
| size_t nops; |
| unsigned int regn; |
| Dwarf_Word offs = 0; |
| bool ref = false; |
| const char *regs; |
| int ret, ret2 = 0; |
| |
| if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL) |
| goto static_var; |
| |
| /* TODO: handle more than 1 exprs */ |
| if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL) |
| return -EINVAL; /* Broken DIE ? */ |
| if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) { |
| ret = dwarf_entrypc(sp_die, &tmp); |
| if (ret) |
| return -ENOENT; |
| |
| if (probe_conf.show_location_range && |
| (dwarf_tag(vr_die) == DW_TAG_variable)) { |
| ret2 = -ERANGE; |
| } else if (addr != tmp || |
| dwarf_tag(vr_die) != DW_TAG_formal_parameter) { |
| return -ENOENT; |
| } |
| |
| ret = dwarf_highpc(sp_die, &tmp); |
| if (ret) |
| return -ENOENT; |
| /* |
| * This is fuzzed by fentry mcount. We try to find the |
| * parameter location at the earliest address. |
| */ |
| for (addr += 1; addr <= tmp; addr++) { |
| if (dwarf_getlocation_addr(&attr, addr, &op, |
| &nops, 1) > 0) |
| goto found; |
| } |
| return -ENOENT; |
| } |
| found: |
| if (nops == 0) |
| /* TODO: Support const_value */ |
| return -ENOENT; |
| |
| if (op->atom == DW_OP_addr) { |
| static_var: |
| if (!tvar) |
| return ret2; |
| /* Static variables on memory (not stack), make @varname */ |
| ret = strlen(dwarf_diename(vr_die)); |
| tvar->value = zalloc(ret + 2); |
| if (tvar->value == NULL) |
| return -ENOMEM; |
| snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die)); |
| tvar->ref = alloc_trace_arg_ref((long)offs); |
| if (tvar->ref == NULL) |
| return -ENOMEM; |
| return ret2; |
| } |
| |
| /* If this is based on frame buffer, set the offset */ |
| if (op->atom == DW_OP_fbreg) { |
| if (fb_ops == NULL) |
| return -ENOTSUP; |
| ref = true; |
| offs = op->number; |
| op = &fb_ops[0]; |
| } |
| |
| if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) { |
| regn = op->atom - DW_OP_breg0; |
| offs += op->number; |
| ref = true; |
| } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) { |
| regn = op->atom - DW_OP_reg0; |
| } else if (op->atom == DW_OP_bregx) { |
| regn = op->number; |
| offs += op->number2; |
| ref = true; |
| } else if (op->atom == DW_OP_regx) { |
| regn = op->number; |
| } else { |
| pr_debug("DW_OP %x is not supported.\n", op->atom); |
| return -ENOTSUP; |
| } |
| |
| if (!tvar) |
| return ret2; |
| |
| regs = get_arch_regstr(regn); |
| if (!regs) { |
| /* This should be a bug in DWARF or this tool */ |
| pr_warning("Mapping for the register number %u " |
| "missing on this architecture.\n", regn); |
| return -ENOTSUP; |
| } |
| |
| tvar->value = strdup(regs); |
| if (tvar->value == NULL) |
| return -ENOMEM; |
| |
| if (ref) { |
| tvar->ref = alloc_trace_arg_ref((long)offs); |
| if (tvar->ref == NULL) |
| return -ENOMEM; |
| } |
| return ret2; |
| } |
| |
| #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long)) |
| |
| static int convert_variable_type(Dwarf_Die *vr_die, |
| struct probe_trace_arg *tvar, |
| const char *cast) |
| { |
| struct probe_trace_arg_ref **ref_ptr = &tvar->ref; |
| Dwarf_Die type; |
| char buf[16]; |
| char sbuf[STRERR_BUFSIZE]; |
| int bsize, boffs, total; |
| int ret; |
| |
| /* TODO: check all types */ |
| if (cast && strcmp(cast, "string") != 0) { |
| /* Non string type is OK */ |
| tvar->type = strdup(cast); |
| return (tvar->type == NULL) ? -ENOMEM : 0; |
| } |
| |
| bsize = dwarf_bitsize(vr_die); |
| if (bsize > 0) { |
| /* This is a bitfield */ |
| boffs = dwarf_bitoffset(vr_die); |
| total = dwarf_bytesize(vr_die); |
| if (boffs < 0 || total < 0) |
| return -ENOENT; |
| ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs, |
| BYTES_TO_BITS(total)); |
| goto formatted; |
| } |
| |
| if (die_get_real_type(vr_die, &type) == NULL) { |
| pr_warning("Failed to get a type information of %s.\n", |
| dwarf_diename(vr_die)); |
| return -ENOENT; |
| } |
| |
| pr_debug("%s type is %s.\n", |
| dwarf_diename(vr_die), dwarf_diename(&type)); |
| |
| if (cast && strcmp(cast, "string") == 0) { /* String type */ |
| ret = dwarf_tag(&type); |
| if (ret != DW_TAG_pointer_type && |
| ret != DW_TAG_array_type) { |
| pr_warning("Failed to cast into string: " |
| "%s(%s) is not a pointer nor array.\n", |
| dwarf_diename(vr_die), dwarf_diename(&type)); |
| return -EINVAL; |
| } |
| if (die_get_real_type(&type, &type) == NULL) { |
| pr_warning("Failed to get a type" |
| " information.\n"); |
| return -ENOENT; |
| } |
| if (ret == DW_TAG_pointer_type) { |
| while (*ref_ptr) |
| ref_ptr = &(*ref_ptr)->next; |
| /* Add new reference with offset +0 */ |
| *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref)); |
| if (*ref_ptr == NULL) { |
| pr_warning("Out of memory error\n"); |
| return -ENOMEM; |
| } |
| } |
| if (!die_compare_name(&type, "char") && |
| !die_compare_name(&type, "unsigned char")) { |
| pr_warning("Failed to cast into string: " |
| "%s is not (unsigned) char *.\n", |
| dwarf_diename(vr_die)); |
| return -EINVAL; |
| } |
| tvar->type = strdup(cast); |
| return (tvar->type == NULL) ? -ENOMEM : 0; |
| } |
| |
| ret = dwarf_bytesize(&type); |
| if (ret <= 0) |
| /* No size ... try to use default type */ |
| return 0; |
| ret = BYTES_TO_BITS(ret); |
| |
| /* Check the bitwidth */ |
| if (ret > MAX_BASIC_TYPE_BITS) { |
| pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n", |
| dwarf_diename(&type), MAX_BASIC_TYPE_BITS); |
| ret = MAX_BASIC_TYPE_BITS; |
| } |
| ret = snprintf(buf, 16, "%c%d", |
| die_is_signed_type(&type) ? 's' : 'u', ret); |
| |
| formatted: |
| if (ret < 0 || ret >= 16) { |
| if (ret >= 16) |
| ret = -E2BIG; |
| pr_warning("Failed to convert variable type: %s\n", |
| strerror_r(-ret, sbuf, sizeof(sbuf))); |
| return ret; |
| } |
| tvar->type = strdup(buf); |
| if (tvar->type == NULL) |
| return -ENOMEM; |
| return 0; |
| } |
| |
| static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname, |
| struct perf_probe_arg_field *field, |
| struct probe_trace_arg_ref **ref_ptr, |
| Dwarf_Die *die_mem) |
| { |
| struct probe_trace_arg_ref *ref = *ref_ptr; |
| Dwarf_Die type; |
| Dwarf_Word offs; |
| int ret, tag; |
| |
| pr_debug("converting %s in %s\n", field->name, varname); |
| if (die_get_real_type(vr_die, &type) == NULL) { |
| pr_warning("Failed to get the type of %s.\n", varname); |
| return -ENOENT; |
| } |
| pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type)); |
| tag = dwarf_tag(&type); |
| |
| if (field->name[0] == '[' && |
| (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) { |
| if (field->next) |
| /* Save original type for next field */ |
| memcpy(die_mem, &type, sizeof(*die_mem)); |
| /* Get the type of this array */ |
| if (die_get_real_type(&type, &type) == NULL) { |
| pr_warning("Failed to get the type of %s.\n", varname); |
| return -ENOENT; |
| } |
| pr_debug2("Array real type: (%x)\n", |
| (unsigned)dwarf_dieoffset(&type)); |
| if (tag == DW_TAG_pointer_type) { |
| ref = zalloc(sizeof(struct probe_trace_arg_ref)); |
| if (ref == NULL) |
| return -ENOMEM; |
| if (*ref_ptr) |
| (*ref_ptr)->next = ref; |
| else |
| *ref_ptr = ref; |
| } |
| ref->offset += dwarf_bytesize(&type) * field->index; |
| if (!field->next) |
| /* Save vr_die for converting types */ |
| memcpy(die_mem, vr_die, sizeof(*die_mem)); |
| goto next; |
| } else if (tag == DW_TAG_pointer_type) { |
| /* Check the pointer and dereference */ |
| if (!field->ref) { |
| pr_err("Semantic error: %s must be referred by '->'\n", |
| field->name); |
| return -EINVAL; |
| } |
| /* Get the type pointed by this pointer */ |
| if (die_get_real_type(&type, &type) == NULL) { |
| pr_warning("Failed to get the type of %s.\n", varname); |
| return -ENOENT; |
| } |
| /* Verify it is a data structure */ |
| tag = dwarf_tag(&type); |
| if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) { |
| pr_warning("%s is not a data structure nor an union.\n", |
| varname); |
| return -EINVAL; |
| } |
| |
| ref = zalloc(sizeof(struct probe_trace_arg_ref)); |
| if (ref == NULL) |
| return -ENOMEM; |
| if (*ref_ptr) |
| (*ref_ptr)->next = ref; |
| else |
| *ref_ptr = ref; |
| } else { |
| /* Verify it is a data structure */ |
| if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) { |
| pr_warning("%s is not a data structure nor an union.\n", |
| varname); |
| return -EINVAL; |
| } |
| if (field->name[0] == '[') { |
| pr_err("Semantic error: %s is not a pointer" |
| " nor array.\n", varname); |
| return -EINVAL; |
| } |
| /* While prcessing unnamed field, we don't care about this */ |
| if (field->ref && dwarf_diename(vr_die)) { |
| pr_err("Semantic error: %s must be referred by '.'\n", |
| field->name); |
| return -EINVAL; |
| } |
| if (!ref) { |
| pr_warning("Structure on a register is not " |
| "supported yet.\n"); |
| return -ENOTSUP; |
| } |
| } |
| |
| if (die_find_member(&type, field->name, die_mem) == NULL) { |
| pr_warning("%s(type:%s) has no member %s.\n", varname, |
| dwarf_diename(&type), field->name); |
| return -EINVAL; |
| } |
| |
| /* Get the offset of the field */ |
| if (tag == DW_TAG_union_type) { |
| offs = 0; |
| } else { |
| ret = die_get_data_member_location(die_mem, &offs); |
| if (ret < 0) { |
| pr_warning("Failed to get the offset of %s.\n", |
| field->name); |
| return ret; |
| } |
| } |
| ref->offset += (long)offs; |
| |
| /* If this member is unnamed, we need to reuse this field */ |
| if (!dwarf_diename(die_mem)) |
| return convert_variable_fields(die_mem, varname, field, |
| &ref, die_mem); |
| |
| next: |
| /* Converting next field */ |
| if (field->next) |
| return convert_variable_fields(die_mem, field->name, |
| field->next, &ref, die_mem); |
| else |
| return 0; |
| } |
| |
| /* Show a variables in kprobe event format */ |
| static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf) |
| { |
| Dwarf_Die die_mem; |
| int ret; |
| |
| pr_debug("Converting variable %s into trace event.\n", |
| dwarf_diename(vr_die)); |
| |
| ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops, |
| &pf->sp_die, pf->tvar); |
| if (ret == -ENOENT || ret == -EINVAL) { |
| pr_err("Failed to find the location of the '%s' variable at this address.\n" |
| " Perhaps it has been optimized out.\n" |
| " Use -V with the --range option to show '%s' location range.\n", |
| pf->pvar->var, pf->pvar->var); |
| } else if (ret == -ENOTSUP) |
| pr_err("Sorry, we don't support this variable location yet.\n"); |
| else if (ret == 0 && pf->pvar->field) { |
| ret = convert_variable_fields(vr_die, pf->pvar->var, |
| pf->pvar->field, &pf->tvar->ref, |
| &die_mem); |
| vr_die = &die_mem; |
| } |
| if (ret == 0) |
| ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type); |
| /* *expr will be cached in libdw. Don't free it. */ |
| return ret; |
| } |
| |
| /* Find a variable in a scope DIE */ |
| static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf) |
| { |
| Dwarf_Die vr_die; |
| char buf[32], *ptr; |
| int ret = 0; |
| |
| /* Copy raw parameters */ |
| if (!is_c_varname(pf->pvar->var)) |
| return copy_to_probe_trace_arg(pf->tvar, pf->pvar); |
| |
| if (pf->pvar->name) |
| pf->tvar->name = strdup(pf->pvar->name); |
| else { |
| ret = synthesize_perf_probe_arg(pf->pvar, buf, 32); |
| if (ret < 0) |
| return ret; |
| ptr = strchr(buf, ':'); /* Change type separator to _ */ |
| if (ptr) |
| *ptr = '_'; |
| pf->tvar->name = strdup(buf); |
| } |
| if (pf->tvar->name == NULL) |
| return -ENOMEM; |
| |
| pr_debug("Searching '%s' variable in context.\n", pf->pvar->var); |
| /* Search child die for local variables and parameters. */ |
| if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) { |
| /* Search again in global variables */ |
| if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, |
| 0, &vr_die)) { |
| pr_warning("Failed to find '%s' in this function.\n", |
| pf->pvar->var); |
| ret = -ENOENT; |
| } |
| } |
| if (ret >= 0) |
| ret = convert_variable(&vr_die, pf); |
| |
| return ret; |
| } |
| |
| /* Convert subprogram DIE to trace point */ |
| static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod, |
| Dwarf_Addr paddr, bool retprobe, |
| const char *function, |
| struct probe_trace_point *tp) |
| { |
| Dwarf_Addr eaddr, highaddr; |
| GElf_Sym sym; |
| const char *symbol; |
| |
| /* Verify the address is correct */ |
| if (dwarf_entrypc(sp_die, &eaddr) != 0) { |
| pr_warning("Failed to get entry address of %s\n", |
| dwarf_diename(sp_die)); |
| return -ENOENT; |
| } |
| if (dwarf_highpc(sp_die, &highaddr) != 0) { |
| pr_warning("Failed to get end address of %s\n", |
| dwarf_diename(sp_die)); |
| return -ENOENT; |
| } |
| if (paddr > highaddr) { |
| pr_warning("Offset specified is greater than size of %s\n", |
| dwarf_diename(sp_die)); |
| return -EINVAL; |
| } |
| |
| symbol = dwarf_diename(sp_die); |
| if (!symbol) { |
| /* Try to get the symbol name from symtab */ |
| symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL); |
| if (!symbol) { |
| pr_warning("Failed to find symbol at 0x%lx\n", |
| (unsigned long)paddr); |
| return -ENOENT; |
| } |
| eaddr = sym.st_value; |
| } |
| tp->offset = (unsigned long)(paddr - eaddr); |
| tp->address = (unsigned long)paddr; |
| tp->symbol = strdup(symbol); |
| if (!tp->symbol) |
| return -ENOMEM; |
| |
| /* Return probe must be on the head of a subprogram */ |
| if (retprobe) { |
| if (eaddr != paddr) { |
| pr_warning("Failed to find \"%s%%return\",\n" |
| " because %s is an inlined function and" |
| " has no return point.\n", function, |
| function); |
| return -EINVAL; |
| } |
| tp->retprobe = true; |
| } |
| |
| return 0; |
| } |
| |
| /* Call probe_finder callback with scope DIE */ |
| static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf) |
| { |
| Dwarf_Attribute fb_attr; |
| size_t nops; |
| int ret; |
| |
| if (!sc_die) { |
| pr_err("Caller must pass a scope DIE. Program error.\n"); |
| return -EINVAL; |
| } |
| |
| /* If not a real subprogram, find a real one */ |
| if (!die_is_func_def(sc_die)) { |
| if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) { |
| if (die_find_tailfunc(&pf->cu_die, pf->addr, &pf->sp_die)) { |
| pr_warning("Ignoring tail call from %s\n", |
| dwarf_diename(&pf->sp_die)); |
| return 0; |
| } else { |
| pr_warning("Failed to find probe point in any " |
| "functions.\n"); |
| return -ENOENT; |
| } |
| } |
| } else |
| memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die)); |
| |
| /* Get the frame base attribute/ops from subprogram */ |
| dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr); |
| ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1); |
| if (ret <= 0 || nops == 0) { |
| pf->fb_ops = NULL; |
| ret = 0; |
| #if _ELFUTILS_PREREQ(0, 142) |
| } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa && |
| pf->cfi != NULL) { |
| Dwarf_Frame *frame = NULL; |
| if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 || |
| dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) { |
| pr_warning("Failed to get call frame on 0x%jx\n", |
| (uintmax_t)pf->addr); |
| ret = -ENOENT; |
| } |
| free(frame); |
| #endif |
| } |
| |
| /* Call finder's callback handler */ |
| if (ret >= 0) |
| ret = pf->callback(sc_die, pf); |
| |
| /* *pf->fb_ops will be cached in libdw. Don't free it. */ |
| pf->fb_ops = NULL; |
| |
| return ret; |
| } |
| |
| struct find_scope_param { |
| const char *function; |
| const char *file; |
| int line; |
| int diff; |
| Dwarf_Die *die_mem; |
| bool found; |
| }; |
| |
| static int find_best_scope_cb(Dwarf_Die *fn_die, void *data) |
| { |
| struct find_scope_param *fsp = data; |
| const char *file; |
| int lno; |
| |
| /* Skip if declared file name does not match */ |
| if (fsp->file) { |
| file = dwarf_decl_file(fn_die); |
| if (!file || strcmp(fsp->file, file) != 0) |
| return 0; |
| } |
| /* If the function name is given, that's what user expects */ |
| if (fsp->function) { |
| if (die_match_name(fn_die, fsp->function)) { |
| memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die)); |
| fsp->found = true; |
| return 1; |
| } |
| } else { |
| /* With the line number, find the nearest declared DIE */ |
| dwarf_decl_line(fn_die, &lno); |
| if (lno < fsp->line && fsp->diff > fsp->line - lno) { |
| /* Keep a candidate and continue */ |
| fsp->diff = fsp->line - lno; |
| memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die)); |
| fsp->found = true; |
| } |
| } |
| return 0; |
| } |
| |
| /* Find an appropriate scope fits to given conditions */ |
| 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); |
| |
| /* Continue if no error, because the line will be in inline function */ |
| return ret < 0 ? ret : 0; |
| } |
| |
| /* Find probe point from its line number */ |
| static int find_probe_point_by_line(struct probe_finder *pf) |
| { |
| return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf); |
| } |
| |
| /* Find lines which match lazy pattern */ |
| static int find_lazy_match_lines(struct intlist *list, |
| const char *fname, const char *pat) |
| { |
| FILE *fp; |
| char *line = NULL; |
| size_t line_len; |
| ssize_t len; |
| int count = 0, linenum = 1; |
| char sbuf[STRERR_BUFSIZE]; |
| |
| fp = fopen(fname, "r"); |
| if (!fp) { |
| pr_warning("Failed to open %s: %s\n", fname, |
| strerror_r(errno, sbuf, sizeof(sbuf))); |
| return -errno; |
| } |
| |
| while ((len = getline(&line, &line_len, fp)) > 0) { |
| |
| if (line[len - 1] == '\n') |
| line[len - 1] = '\0'; |
| |
| if (strlazymatch(line, pat)) { |
| intlist__add(list, 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; |
| } |
| |
| 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 (!intlist__has_entry(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); |
| |
| /* |
| * Continue if no error, because the lazy pattern will match |
| * to other lines |
| */ |
| return ret < 0 ? ret : 0; |
| } |
| |
| /* Find probe points from lazy pattern */ |
| static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf) |
| { |
| int ret = 0; |
| char *fpath; |
| |
| if (intlist__empty(pf->lcache)) { |
| const char *comp_dir; |
| |
| comp_dir = cu_get_comp_dir(&pf->cu_die); |
| ret = get_real_path(pf->fname, comp_dir, &fpath); |
| if (ret < 0) { |
| pr_warning("Failed to find source file path.\n"); |
| return ret; |
| } |
| |
| /* Matching lazy line pattern */ |
| ret = find_lazy_match_lines(pf->lcache, fpath, |
| pf->pev->point.lazy_line); |
| free(fpath); |
| if (ret <= 0) |
| return ret; |
| } |
| |
| return die_walk_lines(sp_die, probe_point_lazy_walker, pf); |
| } |
| |
| 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 { |
| /* Get probe address */ |
| 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; |
| } |
| |
| /* Callback parameter with return value for libdw */ |
| struct dwarf_callback_param { |
| void *data; |
| int retval; |
| }; |
| |
| /* 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 (!die_is_func_def(sp_die) || |
| !die_match_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; |
| |
| pr_debug("Matched function: %s\n", dwarf_diename(sp_die)); |
| 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 (die_is_func_instance(sp_die)) { |
| /* Instances always have the entry address */ |
| dwarf_entrypc(sp_die, &pf->addr); |
| /* Real function */ |
| if (pp->lazy_line) |
| param->retval = find_probe_point_lazy(sp_die, pf); |
| else { |
| pf->addr += pp->offset; |
| /* TODO: Check the address in this function */ |
| param->retval = call_probe_finder(sp_die, pf); |
| } |
| } else if (!probe_conf.no_inlines) { |
| /* Inlined function: search instances */ |
| param->retval = die_walk_instances(sp_die, |
| probe_point_inline_cb, (void *)pf); |
| /* This could be a non-existed inline definition */ |
| if (param->retval == -ENOENT && strisglob(pp->function)) |
| param->retval = 0; |
| } |
| |
| /* We need to find other candidates */ |
| if (strisglob(pp->function) && param->retval >= 0) { |
| param->retval = 0; /* We have to clear the result */ |
| return DWARF_CB_OK; |
| } |
| |
| 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; |
| } |
| |
| struct pubname_callback_param { |
| char *function; |
| char *file; |
| Dwarf_Die *cu_die; |
| Dwarf_Die *sp_die; |
| int found; |
| }; |
| |
| static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data) |
| { |
| struct pubname_callback_param *param = data; |
| |
| if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) { |
| if (dwarf_tag(param->sp_die) != DW_TAG_subprogram) |
| return DWARF_CB_OK; |
| |
| if (die_match_name(param->sp_die, param->function)) { |
| if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die)) |
| return DWARF_CB_OK; |
| |
| if (param->file && |
| strtailcmp(param->file, dwarf_decl_file(param->sp_die))) |
| return DWARF_CB_OK; |
| |
| param->found = 1; |
| return DWARF_CB_ABORT; |
| } |
| } |
| |
| return DWARF_CB_OK; |
| } |
| |
| /* Find probe points from debuginfo */ |
| static int debuginfo__find_probes(struct debuginfo *dbg, |
| struct probe_finder *pf) |
| { |
| struct perf_probe_point *pp = &pf->pev->point; |
| Dwarf_Off off, noff; |
| size_t cuhl; |
| Dwarf_Die *diep; |
| int ret = 0; |
| |
| #if _ELFUTILS_PREREQ(0, 142) |
| Elf *elf; |
| GElf_Ehdr ehdr; |
| GElf_Shdr shdr; |
| |
| /* Get the call frame information from this dwarf */ |
| elf = dwarf_getelf(dbg->dbg); |
| if (elf == NULL) |
| return -EINVAL; |
| |
| if (gelf_getehdr(elf, &ehdr) == NULL) |
| return -EINVAL; |
| |
| if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) && |
| shdr.sh_type == SHT_PROGBITS) { |
| pf->cfi = dwarf_getcfi_elf(elf); |
| } else { |
| pf->cfi = dwarf_getcfi(dbg->dbg); |
| } |
| #endif |
| |
| off = 0; |
| pf->lcache = intlist__new(NULL); |
| if (!pf->lcache) |
| return -ENOMEM; |
| |
| /* Fastpath: lookup by function name from .debug_pubnames section */ |
| if (pp->function && !strisglob(pp->function)) { |
| struct pubname_callback_param pubname_param = { |
| .function = pp->function, |
| .file = pp->file, |
| .cu_die = &pf->cu_die, |
| .sp_die = &pf->sp_die, |
| .found = 0, |
| }; |
| struct dwarf_callback_param probe_param = { |
| .data = pf, |
| }; |
| |
| dwarf_getpubnames(dbg->dbg, pubname_search_cb, |
| &pubname_param, 0); |
| if (pubname_param.found) { |
| ret = probe_point_search_cb(&pf->sp_die, &probe_param); |
| if (ret) |
| goto found; |
| } |
| } |
| |
| /* Loop on CUs (Compilation Unit) */ |
| while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) { |
| /* Get the DIE(Debugging Information Entry) of this CU */ |
| diep = dwarf_offdie(dbg->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(&pf->cu_die, pf); |
| else { |
| pf->lno = pp->line; |
| ret = find_probe_point_by_line(pf); |
| } |
| if (ret < 0) |
| break; |
| } |
| off = noff; |
| } |
| |
| found: |
| intlist__delete(pf->lcache); |
| pf->lcache = NULL; |
| |
| return ret; |
| } |
| |
| struct local_vars_finder { |
| struct probe_finder *pf; |
| struct perf_probe_arg *args; |
| bool vars; |
| int max_args; |
| int nargs; |
| int ret; |
| }; |
| |
| /* Collect available variables in this scope */ |
| static int copy_variables_cb(Dwarf_Die *die_mem, void *data) |
| { |
| struct local_vars_finder *vf = data; |
| struct probe_finder *pf = vf->pf; |
| int tag; |
| |
| tag = dwarf_tag(die_mem); |
| if (tag == DW_TAG_formal_parameter || |
| (tag == DW_TAG_variable && vf->vars)) { |
| if (convert_variable_location(die_mem, vf->pf->addr, |
| vf->pf->fb_ops, &pf->sp_die, |
| NULL) == 0) { |
| vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem); |
| if (vf->args[vf->nargs].var == NULL) { |
| vf->ret = -ENOMEM; |
| return DIE_FIND_CB_END; |
| } |
| pr_debug(" %s", vf->args[vf->nargs].var); |
| vf->nargs++; |
| } |
| } |
| |
| if (dwarf_haspc(die_mem, vf->pf->addr)) |
| return DIE_FIND_CB_CONTINUE; |
| else |
| return DIE_FIND_CB_SIBLING; |
| } |
| |
| static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf, |
| struct perf_probe_arg *args) |
| { |
| Dwarf_Die die_mem; |
| int i; |
| int n = 0; |
| struct local_vars_finder vf = {.pf = pf, .args = args, .vars = false, |
| .max_args = MAX_PROBE_ARGS, .ret = 0}; |
| |
| for (i = 0; i < pf->pev->nargs; i++) { |
| /* var never be NULL */ |
| if (strcmp(pf->pev->args[i].var, PROBE_ARG_VARS) == 0) |
| vf.vars = true; |
| else if (strcmp(pf->pev->args[i].var, PROBE_ARG_PARAMS) != 0) { |
| /* Copy normal argument */ |
| args[n] = pf->pev->args[i]; |
| n++; |
| continue; |
| } |
| pr_debug("Expanding %s into:", pf->pev->args[i].var); |
| vf.nargs = n; |
| /* Special local variables */ |
| die_find_child(sc_die, copy_variables_cb, (void *)&vf, |
| &die_mem); |
| pr_debug(" (%d)\n", vf.nargs - n); |
| if (vf.ret < 0) |
| return vf.ret; |
| n = vf.nargs; |
| } |
| return n; |
| } |
| |
| /* Add a found probe point into trace event list */ |
| static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf) |
| { |
| struct trace_event_finder *tf = |
| container_of(pf, struct trace_event_finder, pf); |
| struct perf_probe_point *pp = &pf->pev->point; |
| struct probe_trace_event *tev; |
| struct perf_probe_arg *args = NULL; |
| 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++]; |
| |
| /* Trace point should be converted from subprogram DIE */ |
| ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr, |
| pp->retprobe, pp->function, &tev->point); |
| if (ret < 0) |
| goto end; |
| |
| tev->point.realname = strdup(dwarf_diename(sc_die)); |
| if (!tev->point.realname) { |
| ret = -ENOMEM; |
| goto end; |
| } |
| |
| pr_debug("Probe point found: %s+%lu\n", tev->point.symbol, |
| tev->point.offset); |
| |
| /* Expand special probe argument if exist */ |
| args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS); |
| if (args == NULL) { |
| ret = -ENOMEM; |
| goto end; |
| } |
| |
| ret = expand_probe_args(sc_die, pf, args); |
| if (ret < 0) |
| goto end; |
| |
| tev->nargs = ret; |
| tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs); |
| if (tev->args == NULL) { |
| ret = -ENOMEM; |
| goto end; |
| } |
| |
| /* Find each argument */ |
| for (i = 0; i < tev->nargs; i++) { |
| pf->pvar = &args[i]; |
| pf->tvar = &tev->args[i]; |
| /* Variable should be found from scope DIE */ |
| ret = find_variable(sc_die, pf); |
| if (ret != 0) |
| break; |
| } |
| |
| end: |
| if (ret) { |
| clear_probe_trace_event(tev); |
| tf->ntevs--; |
| } |
| free(args); |
| return ret; |
| } |
| |
| /* Find probe_trace_events specified by perf_probe_event from debuginfo */ |
| int debuginfo__find_trace_events(struct debuginfo *dbg, |
| struct perf_probe_event *pev, |
| struct probe_trace_event **tevs) |
| { |
| struct trace_event_finder tf = { |
| .pf = {.pev = pev, .callback = add_probe_trace_event}, |
| .max_tevs = probe_conf.max_probes, .mod = dbg->mod}; |
| int ret, i; |
| |
| /* Allocate result tevs array */ |
| *tevs = zalloc(sizeof(struct probe_trace_event) * tf.max_tevs); |
| if (*tevs == NULL) |
| return -ENOMEM; |
| |
| tf.tevs = *tevs; |
| tf.ntevs = 0; |
| |
| ret = debuginfo__find_probes(dbg, &tf.pf); |
| if (ret < 0) { |
| for (i = 0; i < tf.ntevs; i++) |
| clear_probe_trace_event(&tf.tevs[i]); |
| zfree(tevs); |
| return ret; |
| } |
| |
| return (ret < 0) ? ret : tf.ntevs; |
| } |
| |
| /* 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; |
| 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, &af->pf.sp_die, |
| NULL); |
| if (ret == 0 || ret == -ERANGE) { |
| int ret2; |
| bool externs = !af->child; |
| struct strbuf buf; |
| |
| strbuf_init(&buf, 64); |
| |
| if (probe_conf.show_location_range) { |
| if (!externs) { |
| if (ret) |
| strbuf_addf(&buf, "[INV]\t"); |
| else |
| strbuf_addf(&buf, "[VAL]\t"); |
| } else |
| strbuf_addf(&buf, "[EXT]\t"); |
| } |
| |
| ret2 = die_get_varname(die_mem, &buf); |
| |
| if (!ret2 && probe_conf.show_location_range && |
| !externs) { |
| strbuf_addf(&buf, "\t"); |
| ret2 = die_get_var_range(&af->pf.sp_die, |
| die_mem, &buf); |
| } |
| |
| pr_debug("Add new var: %s\n", buf.buf); |
| if (ret2 == 0) { |
| strlist__add(vl->vars, |
| strbuf_detach(&buf, NULL)); |
| } |
| strbuf_release(&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 *sc_die, struct probe_finder *pf) |
| { |
| struct available_var_finder *af = |
| container_of(pf, struct available_var_finder, pf); |
| struct perf_probe_point *pp = &pf->pev->point; |
| struct variable_list *vl; |
| Dwarf_Die die_mem; |
| int ret; |
| |
| /* 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++]; |
| |
| /* Trace point should be converted from subprogram DIE */ |
| ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr, |
| pp->retprobe, pp->function, &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(NULL, NULL); |
| if (vl->vars == NULL) |
| return -ENOMEM; |
| af->child = true; |
| die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem); |
| |
| /* Find external variables */ |
| if (!probe_conf.show_ext_vars) |
| goto out; |
| /* Don't need to search child DIE for external vars. */ |
| af->child = false; |
| die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem); |
| |
| out: |
| if (strlist__empty(vl->vars)) { |
| strlist__delete(vl->vars); |
| vl->vars = NULL; |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Find available variables at given probe point |
| * Return the number of found probe points. Return 0 if there is no |
| * matched probe point. Return <0 if an error occurs. |
| */ |
| int debuginfo__find_available_vars_at(struct debuginfo *dbg, |
| struct perf_probe_event *pev, |
| struct variable_list **vls) |
| { |
| struct available_var_finder af = { |
| .pf = {.pev = pev, .callback = add_available_vars}, |
| .mod = dbg->mod, |
| .max_vls = probe_conf.max_probes}; |
| int ret; |
| |
| /* Allocate result vls array */ |
| *vls = zalloc(sizeof(struct variable_list) * af.max_vls); |
| if (*vls == NULL) |
| return -ENOMEM; |
| |
| af.vls = *vls; |
| af.nvls = 0; |
| |
| ret = debuginfo__find_probes(dbg, &af.pf); |
| if (ret < 0) { |
| /* Free vlist for error */ |
| while (af.nvls--) { |
| zfree(&af.vls[af.nvls].point.symbol); |
| strlist__delete(af.vls[af.nvls].vars); |
| } |
| zfree(vls); |
| return ret; |
| } |
| |
| return (ret < 0) ? ret : af.nvls; |
| } |
| |
| /* For the kernel module, we need a special code to get a DIE */ |
| static int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs) |
| { |
| int n, i; |
| Elf32_Word shndx; |
| Elf_Scn *scn; |
| Elf *elf; |
| GElf_Shdr mem, *shdr; |
| const char *p; |
| |
| elf = dwfl_module_getelf(dbg->mod, &dbg->bias); |
| if (!elf) |
| return -EINVAL; |
| |
| /* Get the number of relocations */ |
| n = dwfl_module_relocations(dbg->mod); |
| if (n < 0) |
| return -ENOENT; |
| /* Search the relocation related .text section */ |
| for (i = 0; i < n; i++) { |
| p = dwfl_module_relocation_info(dbg->mod, i, &shndx); |
| if (strcmp(p, ".text") == 0) { |
| /* OK, get the section header */ |
| scn = elf_getscn(elf, shndx); |
| if (!scn) |
| return -ENOENT; |
| shdr = gelf_getshdr(scn, &mem); |
| if (!shdr) |
| return -ENOENT; |
| *offs = shdr->sh_addr; |
| } |
| } |
| return 0; |
| } |
| |
| /* Reverse search */ |
| int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr, |
| struct perf_probe_point *ppt) |
| { |
| Dwarf_Die cudie, spdie, indie; |
| Dwarf_Addr _addr = 0, baseaddr = 0; |
| const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp; |
| int baseline = 0, lineno = 0, ret = 0; |
| bool reloc = false; |
| |
| retry: |
| /* Find cu die */ |
| if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) { |
| if (!reloc && debuginfo__get_text_offset(dbg, &baseaddr) == 0) { |
| addr += baseaddr; |
| reloc = true; |
| goto retry; |
| } |
| pr_warning("Failed to find debug information for address %lx\n", |
| addr); |
| ret = -EINVAL; |
| goto end; |
| } |
| |
| /* Find a corresponding line (filename and lineno) */ |
| cu_find_lineinfo(&cudie, addr, &fname, &lineno); |
| /* Don't care whether it failed or not */ |
| |
| /* Find a corresponding function (name, baseline and baseaddr) */ |
| if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) { |
| /* Get function entry information */ |
| func = basefunc = dwarf_diename(&spdie); |
| if (!func || |
| dwarf_entrypc(&spdie, &baseaddr) != 0 || |
| dwarf_decl_line(&spdie, &baseline) != 0) { |
| lineno = 0; |
| goto post; |
| } |
| |
| fname = dwarf_decl_file(&spdie); |
| if (addr == (unsigned long)baseaddr) { |
| /* Function entry - Relative line number is 0 */ |
| lineno = baseline; |
| goto post; |
| } |
| |
| /* Track down the inline functions step by step */ |
| while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr, |
| &indie)) { |
| /* There is an inline function */ |
| if (dwarf_entrypc(&indie, &_addr) == 0 && |
| _addr == addr) { |
| /* |
| * addr is at an inline function entry. |
| * In this case, lineno should be the call-site |
| * line number. (overwrite lineinfo) |
| */ |
| lineno = die_get_call_lineno(&indie); |
| fname = die_get_call_file(&indie); |
| break; |
| } else { |
| /* |
| * addr is in an inline function body. |
| * Since lineno points one of the lines |
| * of the inline function, baseline should |
| * be the entry line of the inline function. |
| */ |
| tmp = dwarf_diename(&indie); |
| if (!tmp || |
| dwarf_decl_line(&indie, &baseline) != 0) |
| break; |
| func = tmp; |
| spdie = indie; |
| } |
| } |
| /* Verify the lineno and baseline are in a same file */ |
| tmp = dwarf_decl_file(&spdie); |
| if (!tmp || strcmp(tmp, fname) != 0) |
| lineno = 0; |
| } |
| |
| post: |
| /* Make a relative line number or an offset */ |
| if (lineno) |
| ppt->line = lineno - baseline; |
| else if (basefunc) { |
| ppt->offset = addr - (unsigned long)baseaddr; |
| func = basefunc; |
| } |
| |
| /* Duplicate strings */ |
| if (func) { |
| ppt->function = strdup(func); |
| if (ppt->function == NULL) { |
| ret = -ENOMEM; |
| goto end; |
| } |
| } |
| if (fname) { |
| ppt->file = strdup(fname); |
| if (ppt->file == NULL) { |
| zfree(&ppt->function); |
| ret = -ENOMEM; |
| goto end; |
| } |
| } |
| end: |
| if (ret == 0 && (fname || func)) |
| ret = 1; /* Found a point */ |
| return ret; |
| } |
| |
| /* Add a line and store the src path */ |
| static int line_range_add_line(const char *src, unsigned int lineno, |
| struct line_range *lr) |
| { |
| /* Copy source path */ |
| if (!lr->path) { |
| lr->path = strdup(src); |
| if (lr->path == NULL) |
| return -ENOMEM; |
| } |
| return intlist__add(lr->line_list, lineno); |
| } |
| |
| static int line_range_walk_cb(const char *fname, int lineno, |
| Dwarf_Addr addr __maybe_unused, |
| void *data) |
| { |
| struct line_finder *lf = data; |
| int err; |
| |
| if ((strtailcmp(fname, lf->fname) != 0) || |
| (lf->lno_s > lineno || lf->lno_e < lineno)) |
| return 0; |
| |
| err = line_range_add_line(fname, lineno, lf->lr); |
| if (err < 0 && err != -EEXIST) |
| return err; |
| |
| return 0; |
| } |
| |
| /* Find line range from its line number */ |
| static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf) |
| { |
| int ret; |
| |
| ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf); |
| |
| /* Update status */ |
| if (ret >= 0) |
| if (!intlist__empty(lf->lr->line_list)) |
| ret = lf->found = 1; |
| else |
| ret = 0; /* Lines are not found */ |
| else { |
| zfree(&lf->lr->path); |
| } |
| return ret; |
| } |
| |
| static int line_range_inline_cb(Dwarf_Die *in_die, void *data) |
| { |
| int ret = find_line_range_by_line(in_die, data); |
| |
| /* |
| * We have to check all instances of inlined function, because |
| * some execution paths can be optimized out depends on the |
| * function argument of instances. However, if an error occurs, |
| * it should be handled by the caller. |
| */ |
| return ret < 0 ? ret : 0; |
| } |
| |
| /* Search function definition from function name */ |
| static int line_range_search_cb(Dwarf_Die *sp_die, void *data) |
| { |
| struct dwarf_callback_param *param = data; |
| struct line_finder *lf = param->data; |
| struct line_range *lr = lf->lr; |
| |
| /* Check declared file */ |
| if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die))) |
| return DWARF_CB_OK; |
| |
| if (die_is_func_def(sp_die) && |
| die_match_name(sp_die, lr->function)) { |
| lf->fname = dwarf_decl_file(sp_die); |
| dwarf_decl_line(sp_die, &lr->offset); |
| pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset); |
| lf->lno_s = lr->offset + lr->start; |
| if (lf->lno_s < 0) /* Overflow */ |
| lf->lno_s = INT_MAX; |
| lf->lno_e = lr->offset + lr->end; |
| if (lf->lno_e < 0) /* Overflow */ |
| lf->lno_e = INT_MAX; |
| pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e); |
| lr->start = lf->lno_s; |
| lr->end = lf->lno_e; |
| if (!die_is_func_instance(sp_die)) |
| param->retval = die_walk_instances(sp_die, |
| line_range_inline_cb, lf); |
| else |
| param->retval = find_line_range_by_line(sp_die, lf); |
| return DWARF_CB_ABORT; |
| } |
| return DWARF_CB_OK; |
| } |
| |
| static int find_line_range_by_func(struct line_finder *lf) |
| { |
| struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0}; |
| dwarf_getfuncs(&lf->cu_die, line_range_search_cb, ¶m, 0); |
| return param.retval; |
| } |
| |
| int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr) |
| { |
| struct line_finder lf = {.lr = lr, .found = 0}; |
| int ret = 0; |
| Dwarf_Off off = 0, noff; |
| size_t cuhl; |
| Dwarf_Die *diep; |
| const char *comp_dir; |
| |
| /* Fastpath: lookup by function name from .debug_pubnames section */ |
| if (lr->function) { |
| struct pubname_callback_param pubname_param = { |
| .function = lr->function, .file = lr->file, |
| .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0}; |
| struct dwarf_callback_param line_range_param = { |
| .data = (void *)&lf, .retval = 0}; |
| |
| dwarf_getpubnames(dbg->dbg, pubname_search_cb, |
| &pubname_param, 0); |
| if (pubname_param.found) { |
| line_range_search_cb(&lf.sp_die, &line_range_param); |
| if (lf.found) |
| goto found; |
| } |
| } |
| |
| /* Loop on CUs (Compilation Unit) */ |
| while (!lf.found && ret >= 0) { |
| if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, |
| NULL, NULL, NULL) != 0) |
| break; |
| |
| /* Get the DIE(Debugging Information Entry) of this CU */ |
| diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die); |
| if (!diep) |
| continue; |
| |
| /* Check if target file is included. */ |
| if (lr->file) |
| lf.fname = cu_find_realpath(&lf.cu_die, lr->file); |
| else |
| lf.fname = 0; |
| |
| if (!lr->file || lf.fname) { |
| if (lr->function) |
| ret = find_line_range_by_func(&lf); |
| else { |
| lf.lno_s = lr->start; |
| lf.lno_e = lr->end; |
| ret = find_line_range_by_line(NULL, &lf); |
| } |
| } |
| off = noff; |
| } |
| |
| found: |
| /* Store comp_dir */ |
| if (lf.found) { |
| comp_dir = cu_get_comp_dir(&lf.cu_die); |
| if (comp_dir) { |
| lr->comp_dir = strdup(comp_dir); |
| if (!lr->comp_dir) |
| ret = -ENOMEM; |
| } |
| } |
| |
| pr_debug("path: %s\n", lr->path); |
| return (ret < 0) ? ret : lf.found; |
| } |
| |
| /* |
| * Find a src file from a DWARF tag path. Prepend optional source path prefix |
| * and chop off leading directories that do not exist. Result is passed back as |
| * a newly allocated path on success. |
| * Return 0 if file was found and readable, -errno otherwise. |
| */ |
| int get_real_path(const char *raw_path, const char *comp_dir, |
| char **new_path) |
| { |
| const char *prefix = symbol_conf.source_prefix; |
| |
| if (!prefix) { |
| if (raw_path[0] != '/' && comp_dir) |
| /* If not an absolute path, try to use comp_dir */ |
| prefix = comp_dir; |
| else { |
| if (access(raw_path, R_OK) == 0) { |
| *new_path = strdup(raw_path); |
| return *new_path ? 0 : -ENOMEM; |
| } else |
| return -errno; |
| } |
| } |
| |
| *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2)); |
| if (!*new_path) |
| return -ENOMEM; |
| |
| for (;;) { |
| sprintf(*new_path, "%s/%s", prefix, raw_path); |
| |
| if (access(*new_path, R_OK) == 0) |
| return 0; |
| |
| if (!symbol_conf.source_prefix) { |
| /* In case of searching comp_dir, don't retry */ |
| zfree(new_path); |
| return -errno; |
| } |
| |
| switch (errno) { |
| case ENAMETOOLONG: |
| case ENOENT: |
| case EROFS: |
| case EFAULT: |
| raw_path = strchr(++raw_path, '/'); |
| if (!raw_path) { |
| zfree(new_path); |
| return -ENOENT; |
| } |
| continue; |
| |
| default: |
| zfree(new_path); |
| return -errno; |
| } |
| } |
| } |