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* probe-finder.c : C expression to kprobe event converter
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* Written by Masami Hiramatsu <mhiramat@redhat.com>
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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#include <sys/utsname.h>
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#include <sys/types.h>
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#include <dwarf-regs.h>
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#include <linux/bitops.h>
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#include "probe-finder.h"
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/* Kprobe tracer basic type is up to u64 */
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#define MAX_BASIC_TYPE_BITS 64
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/* Line number list operations */
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/* Add a line to line number list */
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static int line_list__add_line(struct list_head *head, int line)
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/* Reverse search, because new line will be the last one */
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list_for_each_entry_reverse(ln, head, list) {
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if (ln->line < line) {
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} else if (ln->line == line) /* Already exist */
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/* List is empty, or the smallest entry */
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pr_debug("line list: add a line %u\n", line);
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ln = zalloc(sizeof(struct line_node));
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INIT_LIST_HEAD(&ln->list);
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list_add(&ln->list, p);
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/* Check if the line in line number list */
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static int line_list__has_line(struct list_head *head, int line)
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/* Reverse search, because new line will be the last one */
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list_for_each_entry(ln, head, list)
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/* Init line number list */
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static void line_list__init(struct list_head *head)
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/* Free line number list */
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static void line_list__free(struct list_head *head)
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while (!list_empty(head)) {
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ln = list_first_entry(head, struct line_node, list);
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/* Dwarf FL wrappers */
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static char *debuginfo_path; /* Currently dummy */
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static const Dwfl_Callbacks offline_callbacks = {
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.find_debuginfo = dwfl_standard_find_debuginfo,
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.debuginfo_path = &debuginfo_path,
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.section_address = dwfl_offline_section_address,
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/* We use this table for core files too. */
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.find_elf = dwfl_build_id_find_elf,
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/* Get a Dwarf from offline image */
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static int debuginfo__init_offline_dwarf(struct debuginfo *self,
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fd = open(path, O_RDONLY);
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self->dwfl = dwfl_begin(&offline_callbacks);
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mod = dwfl_report_offline(self->dwfl, "", "", fd);
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self->dbg = dwfl_module_getdwarf(mod, &self->bias);
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dwfl_end(self->dwfl);
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memset(self, 0, sizeof(*self));
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#if _ELFUTILS_PREREQ(0, 148)
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/* This method is buggy if elfutils is older than 0.148 */
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static int __linux_kernel_find_elf(Dwfl_Module *mod,
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const char *module_name,
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char **file_name, Elf **elfp)
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const char *path = kernel_get_module_path(module_name);
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pr_debug2("Use file %s for %s\n", path, module_name);
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fd = open(path, O_RDONLY);
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*file_name = strdup(path);
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/* If failed, try to call standard method */
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return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
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static const Dwfl_Callbacks kernel_callbacks = {
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.find_debuginfo = dwfl_standard_find_debuginfo,
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.debuginfo_path = &debuginfo_path,
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.find_elf = __linux_kernel_find_elf,
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.section_address = dwfl_linux_kernel_module_section_address,
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/* Get a Dwarf from live kernel image */
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static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
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self->dwfl = dwfl_begin(&kernel_callbacks);
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/* Load the kernel dwarves: Don't care the result here */
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dwfl_linux_kernel_report_kernel(self->dwfl);
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dwfl_linux_kernel_report_modules(self->dwfl);
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self->dbg = dwfl_addrdwarf(self->dwfl, addr, &self->bias);
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/* Here, check whether we could get a real dwarf */
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pr_debug("Failed to find kernel dwarf at %lx\n",
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(unsigned long)addr);
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dwfl_end(self->dwfl);
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memset(self, 0, sizeof(*self));
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/* With older elfutils, this just support kernel module... */
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static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
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Dwarf_Addr addr __used)
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const char *path = kernel_get_module_path("kernel");
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pr_err("Failed to find vmlinux path\n");
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pr_debug2("Use file %s for debuginfo\n", path);
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return debuginfo__init_offline_dwarf(self, path);
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struct debuginfo *debuginfo__new(const char *path)
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struct debuginfo *self = zalloc(sizeof(struct debuginfo));
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if (debuginfo__init_offline_dwarf(self, path) < 0) {
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struct debuginfo *debuginfo__new_online_kernel(unsigned long addr)
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struct debuginfo *self = zalloc(sizeof(struct debuginfo));
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if (debuginfo__init_online_kernel_dwarf(self, (Dwarf_Addr)addr) < 0) {
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void debuginfo__delete(struct debuginfo *self)
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dwfl_end(self->dwfl);
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* Probe finder related functions
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static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
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struct probe_trace_arg_ref *ref;
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ref = zalloc(sizeof(struct probe_trace_arg_ref));
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* Convert a location into trace_arg.
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* If tvar == NULL, this just checks variable can be converted.
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static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
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struct probe_trace_arg *tvar)
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Dwarf_Attribute attr;
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if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
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/* TODO: handle more than 1 exprs */
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if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
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dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
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/* TODO: Support const_value */
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if (op->atom == DW_OP_addr) {
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/* Static variables on memory (not stack), make @varname */
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ret = strlen(dwarf_diename(vr_die));
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tvar->value = zalloc(ret + 2);
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if (tvar->value == NULL)
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snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
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tvar->ref = alloc_trace_arg_ref((long)offs);
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if (tvar->ref == NULL)
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/* If this is based on frame buffer, set the offset */
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if (op->atom == DW_OP_fbreg) {
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if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
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regn = op->atom - DW_OP_breg0;
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} else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
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regn = op->atom - DW_OP_reg0;
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} else if (op->atom == DW_OP_bregx) {
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} else if (op->atom == DW_OP_regx) {
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pr_debug("DW_OP %x is not supported.\n", op->atom);
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regs = get_arch_regstr(regn);
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/* This should be a bug in DWARF or this tool */
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pr_warning("Mapping for the register number %u "
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"missing on this architecture.\n", regn);
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tvar->value = strdup(regs);
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if (tvar->value == NULL)
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tvar->ref = alloc_trace_arg_ref((long)offs);
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if (tvar->ref == NULL)
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#define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
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static int convert_variable_type(Dwarf_Die *vr_die,
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struct probe_trace_arg *tvar,
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struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
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int bsize, boffs, total;
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/* TODO: check all types */
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if (cast && strcmp(cast, "string") != 0) {
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/* Non string type is OK */
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tvar->type = strdup(cast);
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return (tvar->type == NULL) ? -ENOMEM : 0;
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bsize = dwarf_bitsize(vr_die);
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/* This is a bitfield */
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boffs = dwarf_bitoffset(vr_die);
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total = dwarf_bytesize(vr_die);
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if (boffs < 0 || total < 0)
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ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
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BYTES_TO_BITS(total));
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if (die_get_real_type(vr_die, &type) == NULL) {
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pr_warning("Failed to get a type information of %s.\n",
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dwarf_diename(vr_die));
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pr_debug("%s type is %s.\n",
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dwarf_diename(vr_die), dwarf_diename(&type));
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if (cast && strcmp(cast, "string") == 0) { /* String type */
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ret = dwarf_tag(&type);
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if (ret != DW_TAG_pointer_type &&
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ret != DW_TAG_array_type) {
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pr_warning("Failed to cast into string: "
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"%s(%s) is not a pointer nor array.\n",
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dwarf_diename(vr_die), dwarf_diename(&type));
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if (ret == DW_TAG_pointer_type) {
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if (die_get_real_type(&type, &type) == NULL) {
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pr_warning("Failed to get a type"
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ref_ptr = &(*ref_ptr)->next;
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/* Add new reference with offset +0 */
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*ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
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if (*ref_ptr == NULL) {
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pr_warning("Out of memory error\n");
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if (!die_compare_name(&type, "char") &&
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!die_compare_name(&type, "unsigned char")) {
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pr_warning("Failed to cast into string: "
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"%s is not (unsigned) char *.\n",
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dwarf_diename(vr_die));
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tvar->type = strdup(cast);
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return (tvar->type == NULL) ? -ENOMEM : 0;
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ret = dwarf_bytesize(&type);
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/* No size ... try to use default type */
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ret = BYTES_TO_BITS(ret);
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/* Check the bitwidth */
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if (ret > MAX_BASIC_TYPE_BITS) {
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pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
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dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
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ret = MAX_BASIC_TYPE_BITS;
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ret = snprintf(buf, 16, "%c%d",
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die_is_signed_type(&type) ? 's' : 'u', ret);
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if (ret < 0 || ret >= 16) {
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pr_warning("Failed to convert variable type: %s\n",
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tvar->type = strdup(buf);
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if (tvar->type == NULL)
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static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
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struct perf_probe_arg_field *field,
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struct probe_trace_arg_ref **ref_ptr,
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struct probe_trace_arg_ref *ref = *ref_ptr;
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pr_debug("converting %s in %s\n", field->name, varname);
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if (die_get_real_type(vr_die, &type) == NULL) {
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pr_warning("Failed to get the type of %s.\n", varname);
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pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
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tag = dwarf_tag(&type);
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if (field->name[0] == '[' &&
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(tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
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/* Save original type for next field */
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memcpy(die_mem, &type, sizeof(*die_mem));
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/* Get the type of this array */
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if (die_get_real_type(&type, &type) == NULL) {
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pr_warning("Failed to get the type of %s.\n", varname);
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pr_debug2("Array real type: (%x)\n",
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(unsigned)dwarf_dieoffset(&type));
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if (tag == DW_TAG_pointer_type) {
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ref = zalloc(sizeof(struct probe_trace_arg_ref));
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(*ref_ptr)->next = ref;
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ref->offset += dwarf_bytesize(&type) * field->index;
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/* Save vr_die for converting types */
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memcpy(die_mem, vr_die, sizeof(*die_mem));
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} else if (tag == DW_TAG_pointer_type) {
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/* Check the pointer and dereference */
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pr_err("Semantic error: %s must be referred by '->'\n",
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/* Get the type pointed by this pointer */
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if (die_get_real_type(&type, &type) == NULL) {
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pr_warning("Failed to get the type of %s.\n", varname);
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/* Verify it is a data structure */
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if (dwarf_tag(&type) != DW_TAG_structure_type) {
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pr_warning("%s is not a data structure.\n", varname);
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ref = zalloc(sizeof(struct probe_trace_arg_ref));
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(*ref_ptr)->next = ref;
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/* Verify it is a data structure */
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if (tag != DW_TAG_structure_type) {
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pr_warning("%s is not a data structure.\n", varname);
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if (field->name[0] == '[') {
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pr_err("Semantic error: %s is not a pointor"
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" nor array.\n", varname);
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pr_err("Semantic error: %s must be referred by '.'\n",
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pr_warning("Structure on a register is not "
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if (die_find_member(&type, field->name, die_mem) == NULL) {
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pr_warning("%s(tyep:%s) has no member %s.\n", varname,
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dwarf_diename(&type), field->name);
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/* Get the offset of the field */
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ret = die_get_data_member_location(die_mem, &offs);
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pr_warning("Failed to get the offset of %s.\n", field->name);
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ref->offset += (long)offs;
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/* Converting next field */
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return convert_variable_fields(die_mem, field->name,
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field->next, &ref, die_mem);
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/* Show a variables in kprobe event format */
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static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
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pr_debug("Converting variable %s into trace event.\n",
594
dwarf_diename(vr_die));
596
ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
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pr_err("Failed to find the location of %s at this address.\n"
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" Perhaps, it has been optimized out.\n", pf->pvar->var);
601
else if (ret == -ENOTSUP)
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pr_err("Sorry, we don't support this variable location yet.\n");
603
else if (pf->pvar->field) {
604
ret = convert_variable_fields(vr_die, pf->pvar->var,
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pf->pvar->field, &pf->tvar->ref,
610
ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
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/* *expr will be cached in libdw. Don't free it. */
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/* Find a variable in a scope DIE */
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static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
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if (!is_c_varname(pf->pvar->var)) {
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/* Copy raw parameters */
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pf->tvar->value = strdup(pf->pvar->var);
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if (pf->tvar->value == NULL)
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if (pf->pvar->type) {
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pf->tvar->type = strdup(pf->pvar->type);
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if (pf->tvar->type == NULL)
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if (pf->pvar->name) {
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pf->tvar->name = strdup(pf->pvar->name);
634
if (pf->tvar->name == NULL)
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pf->tvar->name = NULL;
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pf->tvar->name = strdup(pf->pvar->name);
644
ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
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ptr = strchr(buf, ':'); /* Change type separator to _ */
650
pf->tvar->name = strdup(buf);
652
if (pf->tvar->name == NULL)
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pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
656
/* Search child die for local variables and parameters. */
657
if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
658
/* Search again in global variables */
659
if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die))
663
ret = convert_variable(&vr_die, pf);
666
pr_warning("Failed to find '%s' in this function.\n",
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/* Convert subprogram DIE to trace point */
672
static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
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bool retprobe, struct probe_trace_point *tp)
678
/* Copy the name of probe point */
679
name = dwarf_diename(sp_die);
681
if (dwarf_entrypc(sp_die, &eaddr) != 0) {
682
pr_warning("Failed to get entry address of %s\n",
683
dwarf_diename(sp_die));
686
tp->symbol = strdup(name);
687
if (tp->symbol == NULL)
689
tp->offset = (unsigned long)(paddr - eaddr);
691
/* This function has no name. */
692
tp->offset = (unsigned long)paddr;
694
/* Return probe must be on the head of a subprogram */
696
if (eaddr != paddr) {
697
pr_warning("Return probe must be on the head of"
698
" a real function.\n");
707
/* Call probe_finder callback with scope DIE */
708
static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
710
Dwarf_Attribute fb_attr;
715
pr_err("Caller must pass a scope DIE. Program error.\n");
719
/* If not a real subprogram, find a real one */
720
if (dwarf_tag(sc_die) != DW_TAG_subprogram) {
721
if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
722
pr_warning("Failed to find probe point in any "
727
memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
729
/* Get the frame base attribute/ops from subprogram */
730
dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
731
ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
732
if (ret <= 0 || nops == 0) {
734
#if _ELFUTILS_PREREQ(0, 142)
735
} else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
738
if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
739
dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
740
pr_warning("Failed to get call frame on 0x%jx\n",
741
(uintmax_t)pf->addr);
747
/* Call finder's callback handler */
748
ret = pf->callback(sc_die, pf);
750
/* *pf->fb_ops will be cached in libdw. Don't free it. */
756
struct find_scope_param {
757
const char *function;
765
static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
767
struct find_scope_param *fsp = data;
771
/* Skip if declared file name does not match */
773
file = dwarf_decl_file(fn_die);
774
if (!file || strcmp(fsp->file, file) != 0)
777
/* If the function name is given, that's what user expects */
779
if (die_compare_name(fn_die, fsp->function)) {
780
memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
785
/* With the line number, find the nearest declared DIE */
786
dwarf_decl_line(fn_die, &lno);
787
if (lno < fsp->line && fsp->diff > fsp->line - lno) {
788
/* Keep a candidate and continue */
789
fsp->diff = fsp->line - lno;
790
memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
797
/* Find an appropriate scope fits to given conditions */
798
static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
800
struct find_scope_param fsp = {
801
.function = pf->pev->point.function,
809
cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
811
return fsp.found ? die_mem : NULL;
814
static int probe_point_line_walker(const char *fname, int lineno,
815
Dwarf_Addr addr, void *data)
817
struct probe_finder *pf = data;
818
Dwarf_Die *sc_die, die_mem;
821
if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
825
sc_die = find_best_scope(pf, &die_mem);
827
pr_warning("Failed to find scope of probe point.\n");
831
ret = call_probe_finder(sc_die, pf);
833
/* Continue if no error, because the line will be in inline function */
834
return ret < 0 ? ret : 0;
837
/* Find probe point from its line number */
838
static int find_probe_point_by_line(struct probe_finder *pf)
840
return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
843
/* Find lines which match lazy pattern */
844
static int find_lazy_match_lines(struct list_head *head,
845
const char *fname, const char *pat)
851
int count = 0, linenum = 1;
853
fp = fopen(fname, "r");
855
pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
859
while ((len = getline(&line, &line_len, fp)) > 0) {
861
if (line[len - 1] == '\n')
862
line[len - 1] = '\0';
864
if (strlazymatch(line, pat)) {
865
line_list__add_line(head, linenum);
877
pr_debug("No matched lines found in %s.\n", fname);
881
static int probe_point_lazy_walker(const char *fname, int lineno,
882
Dwarf_Addr addr, void *data)
884
struct probe_finder *pf = data;
885
Dwarf_Die *sc_die, die_mem;
888
if (!line_list__has_line(&pf->lcache, lineno) ||
889
strtailcmp(fname, pf->fname) != 0)
892
pr_debug("Probe line found: line:%d addr:0x%llx\n",
893
lineno, (unsigned long long)addr);
896
sc_die = find_best_scope(pf, &die_mem);
898
pr_warning("Failed to find scope of probe point.\n");
902
ret = call_probe_finder(sc_die, pf);
905
* Continue if no error, because the lazy pattern will match
908
return ret < 0 ? ret : 0;
911
/* Find probe points from lazy pattern */
912
static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
916
if (list_empty(&pf->lcache)) {
917
/* Matching lazy line pattern */
918
ret = find_lazy_match_lines(&pf->lcache, pf->fname,
919
pf->pev->point.lazy_line);
924
return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
927
static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
929
struct probe_finder *pf = data;
930
struct perf_probe_point *pp = &pf->pev->point;
935
ret = find_probe_point_lazy(in_die, pf);
937
/* Get probe address */
938
if (dwarf_entrypc(in_die, &addr) != 0) {
939
pr_warning("Failed to get entry address of %s.\n",
940
dwarf_diename(in_die));
944
pf->addr += pp->offset;
945
pr_debug("found inline addr: 0x%jx\n",
946
(uintmax_t)pf->addr);
948
ret = call_probe_finder(in_die, pf);
954
/* Callback parameter with return value for libdw */
955
struct dwarf_callback_param {
960
/* Search function from function name */
961
static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
963
struct dwarf_callback_param *param = data;
964
struct probe_finder *pf = param->data;
965
struct perf_probe_point *pp = &pf->pev->point;
967
/* Check tag and diename */
968
if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
969
!die_compare_name(sp_die, pp->function))
972
/* Check declared file */
973
if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
976
pf->fname = dwarf_decl_file(sp_die);
977
if (pp->line) { /* Function relative line */
978
dwarf_decl_line(sp_die, &pf->lno);
980
param->retval = find_probe_point_by_line(pf);
981
} else if (!dwarf_func_inline(sp_die)) {
984
param->retval = find_probe_point_lazy(sp_die, pf);
986
if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
987
pr_warning("Failed to get entry address of "
988
"%s.\n", dwarf_diename(sp_die));
989
param->retval = -ENOENT;
990
return DWARF_CB_ABORT;
992
pf->addr += pp->offset;
993
/* TODO: Check the address in this function */
994
param->retval = call_probe_finder(sp_die, pf);
997
/* Inlined function: search instances */
998
param->retval = die_walk_instances(sp_die,
999
probe_point_inline_cb, (void *)pf);
1001
return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1004
static int find_probe_point_by_func(struct probe_finder *pf)
1006
struct dwarf_callback_param _param = {.data = (void *)pf,
1008
dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1009
return _param.retval;
1012
struct pubname_callback_param {
1020
static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
1022
struct pubname_callback_param *param = data;
1024
if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
1025
if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
1028
if (die_compare_name(param->sp_die, param->function)) {
1029
if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
1033
strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
1037
return DWARF_CB_ABORT;
1044
/* Find probe points from debuginfo */
1045
static int debuginfo__find_probes(struct debuginfo *self,
1046
struct probe_finder *pf)
1048
struct perf_probe_point *pp = &pf->pev->point;
1049
Dwarf_Off off, noff;
1054
#if _ELFUTILS_PREREQ(0, 142)
1055
/* Get the call frame information from this dwarf */
1056
pf->cfi = dwarf_getcfi(self->dbg);
1060
line_list__init(&pf->lcache);
1062
/* Fastpath: lookup by function name from .debug_pubnames section */
1064
struct pubname_callback_param pubname_param = {
1065
.function = pp->function,
1067
.cu_die = &pf->cu_die,
1068
.sp_die = &pf->sp_die,
1071
struct dwarf_callback_param probe_param = {
1075
dwarf_getpubnames(self->dbg, pubname_search_cb,
1077
if (pubname_param.found) {
1078
ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1084
/* Loop on CUs (Compilation Unit) */
1085
while (!dwarf_nextcu(self->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1086
/* Get the DIE(Debugging Information Entry) of this CU */
1087
diep = dwarf_offdie(self->dbg, off + cuhl, &pf->cu_die);
1091
/* Check if target file is included. */
1093
pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1097
if (!pp->file || pf->fname) {
1099
ret = find_probe_point_by_func(pf);
1100
else if (pp->lazy_line)
1101
ret = find_probe_point_lazy(NULL, pf);
1104
ret = find_probe_point_by_line(pf);
1113
line_list__free(&pf->lcache);
1118
/* Add a found probe point into trace event list */
1119
static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1121
struct trace_event_finder *tf =
1122
container_of(pf, struct trace_event_finder, pf);
1123
struct probe_trace_event *tev;
1126
/* Check number of tevs */
1127
if (tf->ntevs == tf->max_tevs) {
1128
pr_warning("Too many( > %d) probe point found.\n",
1132
tev = &tf->tevs[tf->ntevs++];
1134
/* Trace point should be converted from subprogram DIE */
1135
ret = convert_to_trace_point(&pf->sp_die, pf->addr,
1136
pf->pev->point.retprobe, &tev->point);
1140
pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1143
/* Find each argument */
1144
tev->nargs = pf->pev->nargs;
1145
tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1146
if (tev->args == NULL)
1148
for (i = 0; i < pf->pev->nargs; i++) {
1149
pf->pvar = &pf->pev->args[i];
1150
pf->tvar = &tev->args[i];
1151
/* Variable should be found from scope DIE */
1152
ret = find_variable(sc_die, pf);
1160
/* Find probe_trace_events specified by perf_probe_event from debuginfo */
1161
int debuginfo__find_trace_events(struct debuginfo *self,
1162
struct perf_probe_event *pev,
1163
struct probe_trace_event **tevs, int max_tevs)
1165
struct trace_event_finder tf = {
1166
.pf = {.pev = pev, .callback = add_probe_trace_event},
1167
.max_tevs = max_tevs};
1170
/* Allocate result tevs array */
1171
*tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1178
ret = debuginfo__find_probes(self, &tf.pf);
1185
return (ret < 0) ? ret : tf.ntevs;
1188
#define MAX_VAR_LEN 64
1190
/* Collect available variables in this scope */
1191
static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1193
struct available_var_finder *af = data;
1194
struct variable_list *vl;
1195
char buf[MAX_VAR_LEN];
1198
vl = &af->vls[af->nvls - 1];
1200
tag = dwarf_tag(die_mem);
1201
if (tag == DW_TAG_formal_parameter ||
1202
tag == DW_TAG_variable) {
1203
ret = convert_variable_location(die_mem, af->pf.addr,
1204
af->pf.fb_ops, NULL);
1206
ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1207
pr_debug2("Add new var: %s\n", buf);
1209
strlist__add(vl->vars, buf);
1213
if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1214
return DIE_FIND_CB_CONTINUE;
1216
return DIE_FIND_CB_SIBLING;
1219
/* Add a found vars into available variables list */
1220
static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1222
struct available_var_finder *af =
1223
container_of(pf, struct available_var_finder, pf);
1224
struct variable_list *vl;
1228
/* Check number of tevs */
1229
if (af->nvls == af->max_vls) {
1230
pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1233
vl = &af->vls[af->nvls++];
1235
/* Trace point should be converted from subprogram DIE */
1236
ret = convert_to_trace_point(&pf->sp_die, pf->addr,
1237
pf->pev->point.retprobe, &vl->point);
1241
pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1244
/* Find local variables */
1245
vl->vars = strlist__new(true, NULL);
1246
if (vl->vars == NULL)
1249
die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1251
/* Find external variables */
1254
/* Don't need to search child DIE for externs. */
1256
die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1259
if (strlist__empty(vl->vars)) {
1260
strlist__delete(vl->vars);
1267
/* Find available variables at given probe point */
1268
int debuginfo__find_available_vars_at(struct debuginfo *self,
1269
struct perf_probe_event *pev,
1270
struct variable_list **vls,
1271
int max_vls, bool externs)
1273
struct available_var_finder af = {
1274
.pf = {.pev = pev, .callback = add_available_vars},
1275
.max_vls = max_vls, .externs = externs};
1278
/* Allocate result vls array */
1279
*vls = zalloc(sizeof(struct variable_list) * max_vls);
1286
ret = debuginfo__find_probes(self, &af.pf);
1288
/* Free vlist for error */
1290
if (af.vls[af.nvls].point.symbol)
1291
free(af.vls[af.nvls].point.symbol);
1292
if (af.vls[af.nvls].vars)
1293
strlist__delete(af.vls[af.nvls].vars);
1300
return (ret < 0) ? ret : af.nvls;
1303
/* Reverse search */
1304
int debuginfo__find_probe_point(struct debuginfo *self, unsigned long addr,
1305
struct perf_probe_point *ppt)
1307
Dwarf_Die cudie, spdie, indie;
1308
Dwarf_Addr _addr, baseaddr;
1309
const char *fname = NULL, *func = NULL, *tmp;
1310
int baseline = 0, lineno = 0, ret = 0;
1312
/* Adjust address with bias */
1316
if (!dwarf_addrdie(self->dbg, (Dwarf_Addr)addr - self->bias, &cudie)) {
1317
pr_warning("Failed to find debug information for address %lx\n",
1323
/* Find a corresponding line (filename and lineno) */
1324
cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1325
/* Don't care whether it failed or not */
1327
/* Find a corresponding function (name, baseline and baseaddr) */
1328
if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1329
/* Get function entry information */
1330
tmp = dwarf_diename(&spdie);
1332
dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1333
dwarf_decl_line(&spdie, &baseline) != 0)
1337
if (addr == (unsigned long)baseaddr)
1338
/* Function entry - Relative line number is 0 */
1340
else if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1342
if (dwarf_entrypc(&indie, &_addr) == 0 &&
1345
* addr is at an inline function entry.
1346
* In this case, lineno should be the call-site
1349
lineno = die_get_call_lineno(&indie);
1352
* addr is in an inline function body.
1353
* Since lineno points one of the lines
1354
* of the inline function, baseline should
1355
* be the entry line of the inline function.
1357
tmp = dwarf_diename(&indie);
1359
dwarf_decl_line(&spdie, &baseline) == 0)
1366
/* Make a relative line number or an offset */
1368
ppt->line = lineno - baseline;
1370
ppt->offset = addr - (unsigned long)baseaddr;
1372
/* Duplicate strings */
1374
ppt->function = strdup(func);
1375
if (ppt->function == NULL) {
1381
ppt->file = strdup(fname);
1382
if (ppt->file == NULL) {
1383
if (ppt->function) {
1384
free(ppt->function);
1385
ppt->function = NULL;
1392
if (ret == 0 && (fname || func))
1393
ret = 1; /* Found a point */
1397
/* Add a line and store the src path */
1398
static int line_range_add_line(const char *src, unsigned int lineno,
1399
struct line_range *lr)
1401
/* Copy source path */
1403
lr->path = strdup(src);
1404
if (lr->path == NULL)
1407
return line_list__add_line(&lr->line_list, lineno);
1410
static int line_range_walk_cb(const char *fname, int lineno,
1411
Dwarf_Addr addr __used,
1414
struct line_finder *lf = data;
1416
if ((strtailcmp(fname, lf->fname) != 0) ||
1417
(lf->lno_s > lineno || lf->lno_e < lineno))
1420
if (line_range_add_line(fname, lineno, lf->lr) < 0)
1426
/* Find line range from its line number */
1427
static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1431
ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1435
if (!list_empty(&lf->lr->line_list))
1436
ret = lf->found = 1;
1438
ret = 0; /* Lines are not found */
1441
lf->lr->path = NULL;
1446
static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1448
find_line_range_by_line(in_die, data);
1451
* We have to check all instances of inlined function, because
1452
* some execution paths can be optimized out depends on the
1453
* function argument of instances
1458
/* Search function from function name */
1459
static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1461
struct dwarf_callback_param *param = data;
1462
struct line_finder *lf = param->data;
1463
struct line_range *lr = lf->lr;
1465
/* Check declared file */
1466
if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1469
if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1470
die_compare_name(sp_die, lr->function)) {
1471
lf->fname = dwarf_decl_file(sp_die);
1472
dwarf_decl_line(sp_die, &lr->offset);
1473
pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1474
lf->lno_s = lr->offset + lr->start;
1475
if (lf->lno_s < 0) /* Overflow */
1476
lf->lno_s = INT_MAX;
1477
lf->lno_e = lr->offset + lr->end;
1478
if (lf->lno_e < 0) /* Overflow */
1479
lf->lno_e = INT_MAX;
1480
pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1481
lr->start = lf->lno_s;
1482
lr->end = lf->lno_e;
1483
if (dwarf_func_inline(sp_die))
1484
param->retval = die_walk_instances(sp_die,
1485
line_range_inline_cb, lf);
1487
param->retval = find_line_range_by_line(sp_die, lf);
1488
return DWARF_CB_ABORT;
1493
static int find_line_range_by_func(struct line_finder *lf)
1495
struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1496
dwarf_getfuncs(&lf->cu_die, line_range_search_cb, ¶m, 0);
1497
return param.retval;
1500
int debuginfo__find_line_range(struct debuginfo *self, struct line_range *lr)
1502
struct line_finder lf = {.lr = lr, .found = 0};
1504
Dwarf_Off off = 0, noff;
1507
const char *comp_dir;
1509
/* Fastpath: lookup by function name from .debug_pubnames section */
1511
struct pubname_callback_param pubname_param = {
1512
.function = lr->function, .file = lr->file,
1513
.cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1514
struct dwarf_callback_param line_range_param = {
1515
.data = (void *)&lf, .retval = 0};
1517
dwarf_getpubnames(self->dbg, pubname_search_cb,
1519
if (pubname_param.found) {
1520
line_range_search_cb(&lf.sp_die, &line_range_param);
1526
/* Loop on CUs (Compilation Unit) */
1527
while (!lf.found && ret >= 0) {
1528
if (dwarf_nextcu(self->dbg, off, &noff, &cuhl,
1529
NULL, NULL, NULL) != 0)
1532
/* Get the DIE(Debugging Information Entry) of this CU */
1533
diep = dwarf_offdie(self->dbg, off + cuhl, &lf.cu_die);
1537
/* Check if target file is included. */
1539
lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1543
if (!lr->file || lf.fname) {
1545
ret = find_line_range_by_func(&lf);
1547
lf.lno_s = lr->start;
1549
ret = find_line_range_by_line(NULL, &lf);
1556
/* Store comp_dir */
1558
comp_dir = cu_get_comp_dir(&lf.cu_die);
1560
lr->comp_dir = strdup(comp_dir);
1566
pr_debug("path: %s\n", lr->path);
1567
return (ret < 0) ? ret : lf.found;