probe-finder.c 39.9 KB
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/*
 * 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>
32
#include <dwarf-regs.h>
33

34
#include <linux/bitops.h>
35
#include "event.h"
36
#include "dso.h"
37
#include "debug.h"
38
#include "intlist.h"
39
#include "util.h"
40
#include "symbol.h"
41 42
#include "probe-finder.h"

43 44 45
/* Kprobe tracer basic type is up to u64 */
#define MAX_BASIC_TYPE_BITS	64

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/* 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 */
60
static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
61
					 const char *path)
62
{
63
	int fd;
64

65 66 67
	fd = open(path, O_RDONLY);
	if (fd < 0)
		return fd;
68

69 70
	dbg->dwfl = dwfl_begin(&offline_callbacks);
	if (!dbg->dwfl)
71
		goto error;
72

73 74
	dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd);
	if (!dbg->mod)
75 76
		goto error;

77 78
	dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias);
	if (!dbg->dbg)
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		goto error;

	return 0;
82
error:
83 84
	if (dbg->dwfl)
		dwfl_end(dbg->dwfl);
85 86
	else
		close(fd);
87
	memset(dbg, 0, sizeof(*dbg));
88 89

	return -ENOENT;
90 91
}

92
static struct debuginfo *__debuginfo__new(const char *path)
93
{
94 95
	struct debuginfo *dbg = zalloc(sizeof(*dbg));
	if (!dbg)
96 97
		return NULL;

98 99
	if (debuginfo__init_offline_dwarf(dbg, path) < 0)
		zfree(&dbg);
100 101
	if (dbg)
		pr_debug("Open Debuginfo file: %s\n", path);
102
	return dbg;
103 104
}

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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);
}

140
void debuginfo__delete(struct debuginfo *dbg)
141
{
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	if (dbg) {
		if (dbg->dwfl)
			dwfl_end(dbg->dwfl);
		free(dbg);
146
	}
147
}
148

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/*
 * Probe finder related functions
 */

153
static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
154
{
155 156
	struct probe_trace_arg_ref *ref;
	ref = zalloc(sizeof(struct probe_trace_arg_ref));
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	if (ref != NULL)
		ref->offset = offs;
	return ref;
}

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/*
 * Convert a location into trace_arg.
 * If tvar == NULL, this just checks variable can be converted.
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 * If fentry == true and vr_die is a parameter, do huristic search
 * for the location fuzzed by function entry mcount.
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 */
static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
169
				     Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
170
				     struct probe_trace_arg *tvar)
171
{
172
	Dwarf_Attribute attr;
173
	Dwarf_Addr tmp = 0;
174 175
	Dwarf_Op *op;
	size_t nops;
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	unsigned int regn;
	Dwarf_Word offs = 0;
178
	bool ref = false;
179
	const char *regs;
180 181
	int ret;

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	if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
		goto static_var;

185
	/* TODO: handle more than 1 exprs */
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	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;
		}
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		return -ENOENT;
	}
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found:
	if (nops == 0)
		/* TODO: Support const_value */
		return -ENOENT;
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	if (op->atom == DW_OP_addr) {
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static_var:
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		if (!tvar)
			return 0;
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		/* 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;
	}
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	/* If this is based on frame buffer, set the offset */
227
	if (op->atom == DW_OP_fbreg) {
228
		if (fb_ops == NULL)
229
			return -ENOTSUP;
230
		ref = true;
231
		offs = op->number;
232
		op = &fb_ops[0];
233
	}
234

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	if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
		regn = op->atom - DW_OP_breg0;
		offs += op->number;
238
		ref = true;
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	} 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;
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		ref = true;
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	} else if (op->atom == DW_OP_regx) {
		regn = op->number;
247
	} else {
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		pr_debug("DW_OP %x is not supported.\n", op->atom);
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		return -ENOTSUP;
	}
251

252 253 254
	if (!tvar)
		return 0;

255
	regs = get_arch_regstr(regn);
256
	if (!regs) {
257
		/* This should be a bug in DWARF or this tool */
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Masami Hiramatsu 已提交
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		pr_warning("Mapping for the register number %u "
			   "missing on this architecture.\n", regn);
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		return -ERANGE;
	}
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263 264 265 266
	tvar->value = strdup(regs);
	if (tvar->value == NULL)
		return -ENOMEM;

267
	if (ref) {
268
		tvar->ref = alloc_trace_arg_ref((long)offs);
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		if (tvar->ref == NULL)
			return -ENOMEM;
271
	}
272
	return 0;
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}

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#define BYTES_TO_BITS(nb)	((nb) * BITS_PER_LONG / sizeof(long))

277
static int convert_variable_type(Dwarf_Die *vr_die,
278
				 struct probe_trace_arg *tvar,
279
				 const char *cast)
280
{
281
	struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
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	Dwarf_Die type;
	char buf[16];
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	char sbuf[STRERR_BUFSIZE];
285
	int bsize, boffs, total;
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	int ret;

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	/* 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;
	}

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	bsize = dwarf_bitsize(vr_die);
	if (bsize > 0) {
297
		/* This is a bitfield */
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		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));
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		goto formatted;
	}

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	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;
	}
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	pr_debug("%s type is %s.\n",
		 dwarf_diename(vr_die), dwarf_diename(&type));

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	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: "
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Masami Hiramatsu 已提交
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				   "%s(%s) is not a pointer nor array.\n",
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				   dwarf_diename(vr_die), dwarf_diename(&type));
			return -EINVAL;
		}
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		if (die_get_real_type(&type, &type) == NULL) {
			pr_warning("Failed to get a type"
				   " information.\n");
			return -ENOENT;
		}
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		if (ret == DW_TAG_pointer_type) {
			while (*ref_ptr)
				ref_ptr = &(*ref_ptr)->next;
			/* Add new reference with offset +0 */
334
			*ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
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			if (*ref_ptr == NULL) {
				pr_warning("Out of memory error\n");
				return -ENOMEM;
			}
		}
340 341
		if (!die_compare_name(&type, "char") &&
		    !die_compare_name(&type, "unsigned char")) {
342
			pr_warning("Failed to cast into string: "
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Masami Hiramatsu 已提交
343
				   "%s is not (unsigned) char *.\n",
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				   dwarf_diename(vr_die));
			return -EINVAL;
		}
		tvar->type = strdup(cast);
		return (tvar->type == NULL) ? -ENOMEM : 0;
	}

351 352
	ret = dwarf_bytesize(&type);
	if (ret <= 0)
353 354
		/* No size ... try to use default type */
		return 0;
355
	ret = BYTES_TO_BITS(ret);
356

357 358 359 360 361
	/* 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;
362
	}
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	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",
371
			   strerror_r(-ret, sbuf, sizeof(sbuf)));
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		return ret;
	}
	tvar->type = strdup(buf);
	if (tvar->type == NULL)
		return -ENOMEM;
377
	return 0;
378 379
}

380
static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
381
				    struct perf_probe_arg_field *field,
382
				    struct probe_trace_arg_ref **ref_ptr,
383
				    Dwarf_Die *die_mem)
384
{
385
	struct probe_trace_arg_ref *ref = *ref_ptr;
386 387
	Dwarf_Die type;
	Dwarf_Word offs;
388
	int ret, tag;
389 390

	pr_debug("converting %s in %s\n", field->name, varname);
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	if (die_get_real_type(vr_die, &type) == NULL) {
		pr_warning("Failed to get the type of %s.\n", varname);
		return -ENOENT;
	}
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	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) {
411
			ref = zalloc(sizeof(struct probe_trace_arg_ref));
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			if (ref == NULL)
				return -ENOMEM;
			if (*ref_ptr)
				(*ref_ptr)->next = ref;
			else
				*ref_ptr = ref;
		}
419
		ref->offset += dwarf_bytesize(&type) * field->index;
420 421 422 423 424 425
		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 */
426 427 428 429 430
		if (!field->ref) {
			pr_err("Semantic error: %s must be referred by '->'\n",
			       field->name);
			return -EINVAL;
		}
431
		/* Get the type pointed by this pointer */
432 433 434 435
		if (die_get_real_type(&type, &type) == NULL) {
			pr_warning("Failed to get the type of %s.\n", varname);
			return -ENOENT;
		}
436
		/* Verify it is a data structure  */
437 438 439 440
		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);
441 442
			return -EINVAL;
		}
443

444
		ref = zalloc(sizeof(struct probe_trace_arg_ref));
445 446
		if (ref == NULL)
			return -ENOMEM;
447 448 449 450 451
		if (*ref_ptr)
			(*ref_ptr)->next = ref;
		else
			*ref_ptr = ref;
	} else {
452
		/* Verify it is a data structure  */
453 454 455
		if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
			pr_warning("%s is not a data structure nor an union.\n",
				   varname);
456 457
			return -EINVAL;
		}
458
		if (field->name[0] == '[') {
M
Masami Hiramatsu 已提交
459 460
			pr_err("Semantic error: %s is not a pointor"
			       " nor array.\n", varname);
461 462
			return -EINVAL;
		}
463 464 465 466 467 468 469 470 471 472
		if (field->ref) {
			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;
		}
473 474
	}

475
	if (die_find_member(&type, field->name, die_mem) == NULL) {
A
Arnaldo Carvalho de Melo 已提交
476
		pr_warning("%s(type:%s) has no member %s.\n", varname,
477 478 479
			   dwarf_diename(&type), field->name);
		return -EINVAL;
	}
480 481

	/* Get the offset of the field */
482 483 484 485 486 487 488 489 490
	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;
		}
491
	}
492 493
	ref->offset += (long)offs;

494
next:
495 496
	/* Converting next field */
	if (field->next)
497
		return convert_variable_fields(die_mem, field->name,
498
					field->next, &ref, die_mem);
499 500
	else
		return 0;
501 502
}

503
/* Show a variables in kprobe event format */
504
static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
505
{
506
	Dwarf_Die die_mem;
507 508
	int ret;

509 510
	pr_debug("Converting variable %s into trace event.\n",
		 dwarf_diename(vr_die));
511

512
	ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
513
					&pf->sp_die, pf->tvar);
514
	if (ret == -ENOENT || ret == -EINVAL)
515 516 517 518
		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");
519
	else if (ret == 0 && pf->pvar->field) {
520 521 522
		ret = convert_variable_fields(vr_die, pf->pvar->var,
					      pf->pvar->field, &pf->tvar->ref,
					      &die_mem);
523 524
		vr_die = &die_mem;
	}
525 526
	if (ret == 0)
		ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
527
	/* *expr will be cached in libdw. Don't free it. */
528
	return ret;
529 530
}

531 532
/* Find a variable in a scope DIE */
static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
533
{
534
	Dwarf_Die vr_die;
535
	char buf[32], *ptr;
536
	int ret = 0;
537

538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556
	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;
	}

557
	if (pf->pvar->name)
558
		pf->tvar->name = strdup(pf->pvar->name);
559
	else {
560 561 562
		ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
		if (ret < 0)
			return ret;
563 564 565
		ptr = strchr(buf, ':');	/* Change type separator to _ */
		if (ptr)
			*ptr = '_';
566
		pf->tvar->name = strdup(buf);
567
	}
568 569
	if (pf->tvar->name == NULL)
		return -ENOMEM;
570

571
	pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
572
	/* Search child die for local variables and parameters. */
573 574 575
	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))
576 577
			pr_warning("Failed to find '%s' in this function.\n",
				   pf->pvar->var);
578
			ret = -ENOENT;
579
	}
580
	if (ret >= 0)
581 582
		ret = convert_variable(&vr_die, pf);

583
	return ret;
584 585
}

586
/* Convert subprogram DIE to trace point */
587 588 589
static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
				  Dwarf_Addr paddr, bool retprobe,
				  struct probe_trace_point *tp)
590
{
591
	Dwarf_Addr eaddr, highaddr;
592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611
	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;
	}

612
	symbol = dwarf_diename(sp_die);
613
	if (!symbol) {
614 615 616 617 618 619 620 621
		/* 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;
622
	}
623
	tp->offset = (unsigned long)(paddr - eaddr);
624
	tp->address = (unsigned long)paddr;
625 626 627
	tp->symbol = strdup(symbol);
	if (!tp->symbol)
		return -ENOMEM;
628

629
	/* Return probe must be on the head of a subprogram */
630 631
	if (retprobe) {
		if (eaddr != paddr) {
632
			pr_warning("Return probe must be on the head of"
M
Masami Hiramatsu 已提交
633
				   " a real function.\n");
634 635
			return -EINVAL;
		}
636
		tp->retprobe = true;
637 638
	}

639 640 641
	return 0;
}

642 643
/* Call probe_finder callback with scope DIE */
static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
644 645 646 647 648
{
	Dwarf_Attribute fb_attr;
	size_t nops;
	int ret;

649 650 651 652 653 654
	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 */
655
	if (!die_is_func_def(sc_die)) {
656
		if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
657 658 659 660
			pr_warning("Failed to find probe point in any "
				   "functions.\n");
			return -ENOENT;
		}
661 662
	} else
		memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
663

664 665
	/* Get the frame base attribute/ops from subprogram */
	dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
666
	ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
667
	if (ret <= 0 || nops == 0) {
668
		pf->fb_ops = NULL;
669
#if _ELFUTILS_PREREQ(0, 142)
670 671 672
	} else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
		   pf->cfi != NULL) {
		Dwarf_Frame *frame;
673 674
		if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
		    dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
M
Masami Hiramatsu 已提交
675
			pr_warning("Failed to get call frame on 0x%jx\n",
676 677 678
				   (uintmax_t)pf->addr);
			return -ENOENT;
		}
679
#endif
680
	}
681

682
	/* Call finder's callback handler */
683
	ret = pf->callback(sc_die, pf);
684 685 686

	/* *pf->fb_ops will be cached in libdw. Don't free it. */
	pf->fb_ops = NULL;
687 688

	return ret;
689 690
}

691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748
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;
}

749 750
static int probe_point_line_walker(const char *fname, int lineno,
				   Dwarf_Addr addr, void *data)
751
{
752
	struct probe_finder *pf = data;
753
	Dwarf_Die *sc_die, die_mem;
754
	int ret;
755

756 757
	if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
		return 0;
758

759
	pf->addr = addr;
760 761 762 763 764 765 766
	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);
767

768
	/* Continue if no error, because the line will be in inline function */
769
	return ret < 0 ? ret : 0;
770
}
771

772 773 774 775
/* 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);
776 777
}

778
/* Find lines which match lazy pattern */
779
static int find_lazy_match_lines(struct intlist *list,
780 781
				 const char *fname, const char *pat)
{
782 783 784 785 786
	FILE *fp;
	char *line = NULL;
	size_t line_len;
	ssize_t len;
	int count = 0, linenum = 1;
787
	char sbuf[STRERR_BUFSIZE];
788 789 790

	fp = fopen(fname, "r");
	if (!fp) {
791 792
		pr_warning("Failed to open %s: %s\n", fname,
			   strerror_r(errno, sbuf, sizeof(sbuf)));
793
		return -errno;
794 795
	}

796
	while ((len = getline(&line, &line_len, fp)) > 0) {
797

798 799 800 801
		if (line[len - 1] == '\n')
			line[len - 1] = '\0';

		if (strlazymatch(line, pat)) {
802
			intlist__add(list, linenum);
803
			count++;
804
		}
805
		linenum++;
806
	}
807 808 809 810 811 812 813 814 815

	if (ferror(fp))
		count = -errno;
	free(line);
	fclose(fp);

	if (count == 0)
		pr_debug("No matched lines found in %s.\n", fname);
	return count;
816 817
}

818 819 820 821
static int probe_point_lazy_walker(const char *fname, int lineno,
				   Dwarf_Addr addr, void *data)
{
	struct probe_finder *pf = data;
822
	Dwarf_Die *sc_die, die_mem;
823 824
	int ret;

825
	if (!intlist__has_entry(pf->lcache, lineno) ||
826 827 828 829 830 831
	    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;
832 833 834 835 836 837 838 839
	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);
840 841 842 843 844

	/*
	 * Continue if no error, because the lazy pattern will match
	 * to other lines
	 */
845
	return ret < 0 ? ret : 0;
846 847
}

848
/* Find probe points from lazy pattern  */
849
static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
850
{
851
	int ret = 0;
852

853
	if (intlist__empty(pf->lcache)) {
854
		/* Matching lazy line pattern */
855
		ret = find_lazy_match_lines(pf->lcache, pf->fname,
856
					    pf->pev->point.lazy_line);
857
		if (ret <= 0)
858
			return ret;
859 860
	}

861
	return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
862 863
}

864 865
static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
{
866
	struct probe_finder *pf = data;
867
	struct perf_probe_point *pp = &pf->pev->point;
868
	Dwarf_Addr addr;
869
	int ret;
870

871
	if (pp->lazy_line)
872
		ret = find_probe_point_lazy(in_die, pf);
873 874
	else {
		/* Get probe address */
875
		if (dwarf_entrypc(in_die, &addr) != 0) {
M
Masami Hiramatsu 已提交
876
			pr_warning("Failed to get entry address of %s.\n",
877
				   dwarf_diename(in_die));
878
			return -ENOENT;
879 880
		}
		pf->addr = addr;
881 882 883 884
		pf->addr += pp->offset;
		pr_debug("found inline addr: 0x%jx\n",
			 (uintmax_t)pf->addr);

885
		ret = call_probe_finder(in_die, pf);
886
	}
887

888
	return ret;
889
}
890

891 892 893 894 895 896
/* Callback parameter with return value for libdw */
struct dwarf_callback_param {
	void *data;
	int retval;
};

897
/* Search function from function name */
898
static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
899
{
900 901
	struct dwarf_callback_param *param = data;
	struct probe_finder *pf = param->data;
902
	struct perf_probe_point *pp = &pf->pev->point;
903

904
	/* Check tag and diename */
905 906
	if (!die_is_func_def(sp_die) ||
	    !die_compare_name(sp_die, pp->function))
907
		return DWARF_CB_OK;
908

909 910 911 912
	/* Check declared file */
	if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
		return DWARF_CB_OK;

913
	pf->fname = dwarf_decl_file(sp_die);
914 915 916
	if (pp->line) { /* Function relative line */
		dwarf_decl_line(sp_die, &pf->lno);
		pf->lno += pp->line;
917
		param->retval = find_probe_point_by_line(pf);
918 919
	} else if (!dwarf_func_inline(sp_die)) {
		/* Real function */
920
		if (pp->lazy_line)
921
			param->retval = find_probe_point_lazy(sp_die, pf);
922
		else {
923
			if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
M
Masami Hiramatsu 已提交
924 925
				pr_warning("Failed to get entry address of "
					   "%s.\n", dwarf_diename(sp_die));
926 927 928
				param->retval = -ENOENT;
				return DWARF_CB_ABORT;
			}
929 930
			pf->addr += pp->offset;
			/* TODO: Check the address in this function */
931
			param->retval = call_probe_finder(sp_die, pf);
932
		}
933
	} else
934
		/* Inlined function: search instances */
935 936
		param->retval = die_walk_instances(sp_die,
					probe_point_inline_cb, (void *)pf);
937

938
	return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
939 940
}

941
static int find_probe_point_by_func(struct probe_finder *pf)
942
{
943 944 945 946
	struct dwarf_callback_param _param = {.data = (void *)pf,
					      .retval = 0};
	dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
	return _param.retval;
947 948
}

949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980
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;
}

981
/* Find probe points from debuginfo */
982
static int debuginfo__find_probes(struct debuginfo *dbg,
983
				  struct probe_finder *pf)
984
{
985
	struct perf_probe_point *pp = &pf->pev->point;
986 987 988
	Dwarf_Off off, noff;
	size_t cuhl;
	Dwarf_Die *diep;
989
	int ret = 0;
990

991
#if _ELFUTILS_PREREQ(0, 142)
992 993 994 995
	Elf *elf;
	GElf_Ehdr ehdr;
	GElf_Shdr shdr;

996
	/* Get the call frame information from this dwarf */
997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009
	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);
	}
1010
#endif
1011

1012
	off = 0;
1013 1014 1015
	pf->lcache = intlist__new(NULL);
	if (!pf->lcache)
		return -ENOMEM;
1016 1017 1018 1019 1020 1021 1022 1023

	/* 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,
1024
			.found	  = 0,
1025 1026 1027 1028 1029
		};
		struct dwarf_callback_param probe_param = {
			.data = pf,
		};

1030
		dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1031
				  &pubname_param, 0);
1032 1033 1034 1035 1036 1037 1038
		if (pubname_param.found) {
			ret = probe_point_search_cb(&pf->sp_die, &probe_param);
			if (ret)
				goto found;
		}
	}

1039
	/* Loop on CUs (Compilation Unit) */
1040
	while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1041
		/* Get the DIE(Debugging Information Entry) of this CU */
1042
		diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
1043 1044
		if (!diep)
			continue;
1045 1046 1047

		/* Check if target file is included. */
		if (pp->file)
1048
			pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1049
		else
1050
			pf->fname = NULL;
1051

1052
		if (!pp->file || pf->fname) {
1053
			if (pp->function)
1054
				ret = find_probe_point_by_func(pf);
1055
			else if (pp->lazy_line)
1056
				ret = find_probe_point_lazy(NULL, pf);
1057
			else {
1058 1059
				pf->lno = pp->line;
				ret = find_probe_point_by_line(pf);
1060
			}
1061
			if (ret < 0)
1062
				break;
1063
		}
1064
		off = noff;
1065
	}
1066 1067

found:
1068 1069
	intlist__delete(pf->lcache);
	pf->lcache = NULL;
1070

1071 1072 1073
	return ret;
}

1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085
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;
1086
	struct probe_finder *pf = vf->pf;
1087 1088 1089 1090 1091 1092
	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,
1093 1094
					      vf->pf->fb_ops, &pf->sp_die,
					      NULL) == 0) {
1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140
			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;
}

1141
/* Add a found probe point into trace event list */
1142
static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1143 1144 1145 1146
{
	struct trace_event_finder *tf =
			container_of(pf, struct trace_event_finder, pf);
	struct probe_trace_event *tev;
1147
	struct perf_probe_arg *args;
1148 1149 1150 1151 1152 1153 1154 1155 1156 1157
	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++];

1158
	/* Trace point should be converted from subprogram DIE */
1159
	ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1160
				     pf->pev->point.retprobe, &tev->point);
1161 1162 1163 1164 1165 1166
	if (ret < 0)
		return ret;

	pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
		 tev->point.offset);

1167 1168 1169
	/* Expand special probe argument if exist */
	args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
	if (args == NULL)
1170
		return -ENOMEM;
1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185

	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];
1186
		pf->tvar = &tev->args[i];
1187 1188
		/* Variable should be found from scope DIE */
		ret = find_variable(sc_die, pf);
1189
		if (ret != 0)
1190
			break;
1191 1192
	}

1193 1194 1195
end:
	free(args);
	return ret;
1196 1197 1198
}

/* Find probe_trace_events specified by perf_probe_event from debuginfo */
1199
int debuginfo__find_trace_events(struct debuginfo *dbg,
1200 1201
				 struct perf_probe_event *pev,
				 struct probe_trace_event **tevs, int max_tevs)
1202 1203 1204
{
	struct trace_event_finder tf = {
			.pf = {.pev = pev, .callback = add_probe_trace_event},
1205
			.mod = dbg->mod, .max_tevs = max_tevs};
1206 1207 1208 1209 1210 1211 1212 1213 1214 1215
	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;

1216
	ret = debuginfo__find_probes(dbg, &tf.pf);
1217
	if (ret < 0) {
1218
		zfree(tevs);
1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240
		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,
1241 1242
						af->pf.fb_ops, &af->pf.sp_die,
						NULL);
1243 1244
		if (ret == 0) {
			ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1245
			pr_debug2("Add new var: %s\n", buf);
1246 1247 1248 1249 1250
			if (ret > 0)
				strlist__add(vl->vars, buf);
		}
	}

1251
	if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1252 1253 1254 1255 1256 1257
		return DIE_FIND_CB_CONTINUE;
	else
		return DIE_FIND_CB_SIBLING;
}

/* Add a found vars into available variables list */
1258
static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1259 1260 1261 1262
{
	struct available_var_finder *af =
			container_of(pf, struct available_var_finder, pf);
	struct variable_list *vl;
1263 1264
	Dwarf_Die die_mem;
	int ret;
1265 1266 1267 1268 1269 1270 1271 1272

	/* 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++];

1273
	/* Trace point should be converted from subprogram DIE */
1274
	ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1275
				     pf->pev->point.retprobe, &vl->point);
1276 1277 1278 1279 1280 1281 1282 1283 1284 1285
	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;
1286
	af->child = true;
1287
	die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1288

1289 1290 1291 1292 1293
	/* Find external variables */
	if (!af->externs)
		goto out;
	/* Don't need to search child DIE for externs. */
	af->child = false;
1294
	die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1295 1296

out:
1297 1298 1299 1300 1301 1302 1303 1304
	if (strlist__empty(vl->vars)) {
		strlist__delete(vl->vars);
		vl->vars = NULL;
	}

	return ret;
}

1305 1306 1307 1308 1309
/*
 * 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.
 */
1310
int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1311 1312 1313
				      struct perf_probe_event *pev,
				      struct variable_list **vls,
				      int max_vls, bool externs)
1314 1315 1316
{
	struct available_var_finder af = {
			.pf = {.pev = pev, .callback = add_available_vars},
1317
			.mod = dbg->mod,
1318
			.max_vls = max_vls, .externs = externs};
1319 1320 1321 1322 1323 1324 1325 1326 1327 1328
	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;

1329
	ret = debuginfo__find_probes(dbg, &af.pf);
1330 1331 1332
	if (ret < 0) {
		/* Free vlist for error */
		while (af.nvls--) {
1333
			zfree(&af.vls[af.nvls].point.symbol);
1334
			strlist__delete(af.vls[af.nvls].vars);
1335
		}
1336
		zfree(vls);
1337 1338 1339 1340
		return ret;
	}

	return (ret < 0) ? ret : af.nvls;
1341 1342
}

1343
/* Reverse search */
1344
int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
1345
				struct perf_probe_point *ppt)
1346 1347
{
	Dwarf_Die cudie, spdie, indie;
1348 1349
	Dwarf_Addr _addr = 0, baseaddr = 0;
	const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1350
	int baseline = 0, lineno = 0, ret = 0;
1351

1352
	/* Adjust address with bias */
1353
	addr += dbg->bias;
1354

1355
	/* Find cu die */
1356
	if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr - dbg->bias, &cudie)) {
M
Masami Hiramatsu 已提交
1357 1358
		pr_warning("Failed to find debug information for address %lx\n",
			   addr);
1359 1360 1361
		ret = -EINVAL;
		goto end;
	}
1362

1363 1364 1365
	/* Find a corresponding line (filename and lineno) */
	cu_find_lineinfo(&cudie, addr, &fname, &lineno);
	/* Don't care whether it failed or not */
1366

1367
	/* Find a corresponding function (name, baseline and baseaddr) */
1368
	if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1369
		/* Get function entry information */
1370 1371
		func = basefunc = dwarf_diename(&spdie);
		if (!func ||
1372
		    dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1373 1374
		    dwarf_decl_line(&spdie, &baseline) != 0) {
			lineno = 0;
1375
			goto post;
1376
		}
1377

1378
		fname = dwarf_decl_file(&spdie);
1379
		if (addr == (unsigned long)baseaddr) {
1380 1381
			/* Function entry - Relative line number is 0 */
			lineno = baseline;
1382 1383 1384 1385 1386 1387 1388
			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 */
1389
			if (dwarf_entrypc(&indie, &_addr) == 0 &&
1390
			    _addr == addr) {
1391 1392 1393
				/*
				 * addr is at an inline function entry.
				 * In this case, lineno should be the call-site
1394
				 * line number. (overwrite lineinfo)
1395 1396
				 */
				lineno = die_get_call_lineno(&indie);
1397 1398 1399
				fname = die_get_call_file(&indie);
				break;
			} else {
1400 1401 1402 1403 1404 1405
				/*
				 * 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.
				 */
1406
				tmp = dwarf_diename(&indie);
1407 1408 1409 1410 1411
				if (!tmp ||
				    dwarf_decl_line(&indie, &baseline) != 0)
					break;
				func = tmp;
				spdie = indie;
1412
			}
1413
		}
1414 1415 1416 1417
		/* Verify the lineno and baseline are in a same file */
		tmp = dwarf_decl_file(&spdie);
		if (!tmp || strcmp(tmp, fname) != 0)
			lineno = 0;
1418 1419 1420 1421 1422 1423
	}

post:
	/* Make a relative line number or an offset */
	if (lineno)
		ppt->line = lineno - baseline;
1424
	else if (basefunc) {
1425
		ppt->offset = addr - (unsigned long)baseaddr;
1426 1427
		func = basefunc;
	}
1428 1429 1430 1431

	/* Duplicate strings */
	if (func) {
		ppt->function = strdup(func);
1432 1433 1434 1435
		if (ppt->function == NULL) {
			ret = -ENOMEM;
			goto end;
		}
1436
	}
1437 1438 1439
	if (fname) {
		ppt->file = strdup(fname);
		if (ppt->file == NULL) {
1440
			zfree(&ppt->function);
1441 1442 1443 1444
			ret = -ENOMEM;
			goto end;
		}
	}
1445
end:
1446 1447
	if (ret == 0 && (fname || func))
		ret = 1;	/* Found a point */
1448 1449 1450
	return ret;
}

1451 1452 1453 1454
/* Add a line and store the src path */
static int line_range_add_line(const char *src, unsigned int lineno,
			       struct line_range *lr)
{
1455
	/* Copy source path */
1456
	if (!lr->path) {
1457 1458 1459
		lr->path = strdup(src);
		if (lr->path == NULL)
			return -ENOMEM;
1460
	}
1461
	return intlist__add(lr->line_list, lineno);
1462 1463
}

1464
static int line_range_walk_cb(const char *fname, int lineno,
1465
			      Dwarf_Addr addr __maybe_unused,
1466
			      void *data)
1467
{
1468
	struct line_finder *lf = data;
1469
	int err;
1470

1471
	if ((strtailcmp(fname, lf->fname) != 0) ||
1472
	    (lf->lno_s > lineno || lf->lno_e < lineno))
1473
		return 0;
1474

1475 1476 1477
	err = line_range_add_line(fname, lineno, lf->lr);
	if (err < 0 && err != -EEXIST)
		return err;
1478

1479
	return 0;
1480
}
1481

1482
/* Find line range from its line number */
1483
static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1484
{
1485
	int ret;
1486

1487
	ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1488

1489
	/* Update status */
1490
	if (ret >= 0)
1491
		if (!intlist__empty(lf->lr->line_list))
1492 1493 1494
			ret = lf->found = 1;
		else
			ret = 0;	/* Lines are not found */
1495
	else {
1496
		zfree(&lf->lr->path);
1497
	}
1498
	return ret;
1499 1500
}

1501 1502
static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
{
1503
	int ret = find_line_range_by_line(in_die, data);
1504 1505 1506 1507

	/*
	 * We have to check all instances of inlined function, because
	 * some execution paths can be optimized out depends on the
1508 1509
	 * function argument of instances. However, if an error occurs,
	 * it should be handled by the caller.
1510
	 */
1511
	return ret < 0 ? ret : 0;
1512 1513
}

1514
/* Search function definition from function name */
1515
static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1516
{
1517 1518
	struct dwarf_callback_param *param = data;
	struct line_finder *lf = param->data;
1519 1520
	struct line_range *lr = lf->lr;

1521 1522 1523 1524
	/* Check declared file */
	if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
		return DWARF_CB_OK;

1525
	if (die_is_func_def(sp_die) &&
1526
	    die_compare_name(sp_die, lr->function)) {
1527 1528
		lf->fname = dwarf_decl_file(sp_die);
		dwarf_decl_line(sp_die, &lr->offset);
1529
		pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1530
		lf->lno_s = lr->offset + lr->start;
1531 1532 1533 1534
		if (lf->lno_s < 0)	/* Overflow */
			lf->lno_s = INT_MAX;
		lf->lno_e = lr->offset + lr->end;
		if (lf->lno_e < 0)	/* Overflow */
1535
			lf->lno_e = INT_MAX;
1536
		pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1537 1538
		lr->start = lf->lno_s;
		lr->end = lf->lno_e;
1539 1540 1541 1542
		if (dwarf_func_inline(sp_die))
			param->retval = die_walk_instances(sp_die,
						line_range_inline_cb, lf);
		else
1543 1544
			param->retval = find_line_range_by_line(sp_die, lf);
		return DWARF_CB_ABORT;
1545
	}
1546
	return DWARF_CB_OK;
1547 1548
}

1549
static int find_line_range_by_func(struct line_finder *lf)
1550
{
1551 1552 1553
	struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
	dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
	return param.retval;
1554 1555
}

1556
int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1557
{
1558
	struct line_finder lf = {.lr = lr, .found = 0};
1559
	int ret = 0;
1560 1561 1562
	Dwarf_Off off = 0, noff;
	size_t cuhl;
	Dwarf_Die *diep;
1563
	const char *comp_dir;
1564

1565 1566 1567 1568 1569 1570 1571 1572
	/* 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};

1573
		dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1574
				  &pubname_param, 0);
1575 1576 1577 1578 1579 1580 1581
		if (pubname_param.found) {
			line_range_search_cb(&lf.sp_die, &line_range_param);
			if (lf.found)
				goto found;
		}
	}

1582
	/* Loop on CUs (Compilation Unit) */
1583
	while (!lf.found && ret >= 0) {
1584
		if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1585
				 NULL, NULL, NULL) != 0)
1586 1587 1588
			break;

		/* Get the DIE(Debugging Information Entry) of this CU */
1589
		diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1590 1591
		if (!diep)
			continue;
1592 1593 1594

		/* Check if target file is included. */
		if (lr->file)
1595
			lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1596
		else
1597
			lf.fname = 0;
1598

1599
		if (!lr->file || lf.fname) {
1600
			if (lr->function)
1601
				ret = find_line_range_by_func(&lf);
1602 1603
			else {
				lf.lno_s = lr->start;
1604
				lf.lno_e = lr->end;
1605
				ret = find_line_range_by_line(NULL, &lf);
1606 1607
			}
		}
1608
		off = noff;
1609
	}
1610

1611
found:
1612 1613 1614 1615 1616 1617 1618 1619 1620 1621
	/* 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;
		}
	}

1622
	pr_debug("path: %s\n", lr->path);
1623
	return (ret < 0) ? ret : lf.found;
1624 1625
}