path: root/tools/perf/util/probe-finder.c

/*
 * 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 <getopt.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <ctype.h>

#include "event.h"
#include "debug.h"
#include "util.h"
#include "probe-finder.h"


/* Dwarf_Die Linkage to parent Die */
struct die_link {
	struct die_link *parent;	/* Parent die */
	Dwarf_Die die;			/* Current die */
};

static Dwarf_Debug __dw_debug;
static Dwarf_Error __dw_error;

/*
 * Generic dwarf analysis helpers
 */

#define X86_32_MAX_REGS 8
const char *x86_32_regs_table[X86_32_MAX_REGS] = {
	"%ax",
	"%cx",
	"%dx",
	"%bx",
	"$stack",	/* Stack address instead of %sp */
	"%bp",
	"%si",
	"%di",
};

#define X86_64_MAX_REGS 16
const char *x86_64_regs_table[X86_64_MAX_REGS] = {
	"%ax",
	"%dx",
	"%cx",
	"%bx",
	"%si",
	"%di",
	"%bp",
	"%sp",
	"%r8",
	"%r9",
	"%r10",
	"%r11",
	"%r12",
	"%r13",
	"%r14",
	"%r15",
};

/* TODO: switching by dwarf address size */
#ifdef __x86_64__
#define ARCH_MAX_REGS X86_64_MAX_REGS
#define arch_regs_table x86_64_regs_table
#else
#define ARCH_MAX_REGS X86_32_MAX_REGS
#define arch_regs_table x86_32_regs_table
#endif

/* Return architecture dependent register string (for kprobe-tracer) */
static const char *get_arch_regstr(unsigned int n)
{
	return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
}

/*
 * Compare the tail of two strings.
 * Return 0 if whole of either string is same as another's tail part.
 */
static int strtailcmp(const char *s1, const char *s2)
{
	int i1 = strlen(s1);
	int i2 = strlen(s2);
	while (--i1 >= 0 && --i2 >= 0) {
		if (s1[i1] != s2[i2])
			return s1[i1] - s2[i2];
	}
	return 0;
}

/* Find the fileno of the target file. */
static Dwarf_Unsigned cu_find_fileno(Dwarf_Die cu_die, const char *fname)
{
	Dwarf_Signed cnt, i;
	Dwarf_Unsigned found = 0;
	char **srcs;
	int ret;

	if (!fname)
		return 0;

	ret = dwarf_srcfiles(cu_die, &srcs, &cnt, &__dw_error);
	if (ret == DW_DLV_OK) {
		for (i = 0; i < cnt && !found; i++) {
			if (strtailcmp(srcs[i], fname) == 0)
				found = i + 1;
			dwarf_dealloc(__dw_debug, srcs[i], DW_DLA_STRING);
		}
		for (; i < cnt; i++)
			dwarf_dealloc(__dw_debug, srcs[i], DW_DLA_STRING);
		dwarf_dealloc(__dw_debug, srcs, DW_DLA_LIST);
	}
	if (found)
		pr_debug("found fno: %d\n", (int)found);
	return found;
}

static int cu_get_filename(Dwarf_Die cu_die, Dwarf_Unsigned fno, char **buf)
{
	Dwarf_Signed cnt, i;
	char **srcs;
	int ret = 0;

	if (!buf || !fno)
		return -EINVAL;

	ret = dwarf_srcfiles(cu_die, &srcs, &cnt, &__dw_error);
	if (ret == DW_DLV_OK) {
		if ((Dwarf_Unsigned)cnt > fno - 1) {
			*buf = strdup(srcs[fno - 1]);
			ret = 0;
			pr_debug("found filename: %s\n", *buf);
		} else
			ret = -ENOENT;
		for (i = 0; i < cnt; i++)
			dwarf_dealloc(__dw_debug, srcs[i], DW_DLA_STRING);
		dwarf_dealloc(__dw_debug, srcs, DW_DLA_LIST);
	} else
		ret = -EINVAL;
	return ret;
}

/* Compare diename and tname */
static int die_compare_name(Dwarf_Die dw_die, const char *tname)
{
	char *name;
	int ret;
	ret = dwarf_diename(dw_die, &name, &__dw_error);
	DIE_IF(ret == DW_DLV_ERROR);
	if (ret == DW_DLV_OK) {
		ret = strcmp(tname, name);
		dwarf_dealloc(__dw_debug, name, DW_DLA_STRING);
	} else
		ret = -1;
	return ret;
}