--- /dev/null
+/*
+ * 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;
+
+ 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;
+
+ 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__delete(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;
+
+ 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 || addr != tmp ||
+ dwarf_tag(vr_die) != DW_TAG_formal_parameter ||
+ dwarf_highpc(sp_die, &tmp))
+ 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 0;
+ /* 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 0;
+ }
+
+ /* 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 0;
+
+ 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 -ERANGE;
+ }
+
+ 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 0;
+}
+
+#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 %s at this address.\n"
+ " Perhaps, it has been optimized out.\n", 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;
+
+ if (!is_c_varname(pf->pvar->var)) {
+ /* Copy raw parameters */
+ pf->tvar->value = strdup(pf->pvar->var);
+ if (pf->tvar->value == NULL)
+ return -ENOMEM;
+ if (pf->pvar->type) {
+ pf->tvar->type = strdup(pf->pvar->type);
+ if (pf->tvar->type == NULL)
+ return -ENOMEM;
+ }
+ if (pf->pvar->name) {
+ pf->tvar->name = strdup(pf->pvar->name);
+ if (pf->tvar->name == NULL)
+ return -ENOMEM;
+ } else
+ pf->tvar->name = NULL;
+ return 0;
+ }
+
+ 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,
+ 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("Return probe must be on the head of"
+ " a real function.\n");
+ 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)) {
+ 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;
+#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;
+ 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);
+ return -ENOENT;
+ }
+#endif
+ }
+
+ /* Call finder's callback handler */
+ 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_compare_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_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 (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
+ /* 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 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_compare_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) {
+ 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;
+ 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) {
+ 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,
+ .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, "$vars") == 0) {
+ pr_debug("Expanding $vars into:");
+ 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;
+ } else {
+ /* Copy normal argument */
+ args[n] = pf->pev->args[i];
+ n++;
+ }
+ }
+ 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 probe_trace_event *tev;
+ struct perf_probe_arg *args;
+ 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,
+ 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);
+
+ /* Expand special probe argument if exist */
+ args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
+ if (args == NULL)
+ return -ENOMEM;
+
+ 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:
+ 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, int max_tevs)
+{
+ struct trace_event_finder tf = {
+ .pf = {.pev = pev, .callback = add_probe_trace_event},
+ .mod = dbg->mod, .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 = debuginfo__find_probes(dbg, &tf.pf);
+ if (ret < 0) {
+ zfree(tevs);
+ 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, &af->pf.sp_die,
+ 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 *sc_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;
+ 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,
+ 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(sc_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;
+ 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,
+ int max_vls, bool externs)
+{
+ struct available_var_finder af = {
+ .pf = {.pev = pev, .callback = add_available_vars},
+ .mod = dbg->mod,
+ .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 = 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;
+}
+
+/* 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;
+
+ /* Find cu die */
+ if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) {
+ 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_compare_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;
+ }
+ }
+}
Code Review / kvmfornfv.git / blobdiff