perf probe: Remove die() from probe-finder code (b55a87ad) · Commits · e / devices / android_kernel_teracube_emerald

tools/perf/util/probe-event.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -151,10 +151,10 @@ static int try_to_find_kprobe_trace_events(struct perf_probe_event *pev,

		/* Error path */
		if (need_dwarf) {
		if (ntevs == -ENOENT)
		if (ntevs == -EBADF)
		pr_warning("No dwarf info found in the vmlinux - "
		"please rebuild with CONFIG_DEBUG_INFO=y.\n");
		die("Could not analyze debuginfo.");
		die("Failed to analyze debuginfo.");
		}
		pr_debug("An error occurred in debuginfo analysis."
		" Try to use symbols.\n");

tools/perf/util/probe-finder.c

+320 −197

Original line number	Diff line number	Diff line
		@@ -196,19 +196,7 @@ static bool die_compare_name(Dwarf_Die dw_die, const char tname)
		{
		const char *name;
		name = dwarf_diename(dw_die);
		DIE_IF(name == NULL);
		return strcmp(tname, name);
		}

		/* Get entry pc(or low pc, 1st entry of ranges) of the die */
		static Dwarf_Addr die_get_entrypc(Dwarf_Die *dw_die)
		{
		Dwarf_Addr epc;
		int ret;

		ret = dwarf_entrypc(dw_die, &epc);
		DIE_IF(ret == -1);
		return epc;
		return name ? strcmp(tname, name) : -1;
		}

		/* Get type die, but skip qualifiers and typedef */
		@@ -390,7 +378,7 @@ static Dwarf_Die die_find_member(Dwarf_Die st_die, const char *name,
		*/

		/* Show a location */
		static void convert_location(Dwarf_Op op, struct probe_finder pf)
		static int convert_location(Dwarf_Op op, struct probe_finder pf)
		{
		unsigned int regn;
		Dwarf_Word offs = 0;
		@@ -400,8 +388,11 @@ static void convert_location(Dwarf_Op op, struct probe_finder pf)

		/* If this is based on frame buffer, set the offset */
		if (op->atom == DW_OP_fbreg) {
		if (pf->fb_ops == NULL)
		die("The attribute of frame base is not supported.\n");
		if (pf->fb_ops == NULL) {
		pr_warning("The attribute of frame base is not "
		"supported.\n");
		return -ENOTSUP;
		}
		ref = true;
		offs = op->number;
		op = &pf->fb_ops[0];
		@@ -419,36 +410,43 @@ static void convert_location(Dwarf_Op op, struct probe_finder pf)
		ref = true;
		} else if (op->atom == DW_OP_regx) {
		regn = op->number;
		} else
		die("DW_OP %d is not supported.", op->atom);
		} else {
		pr_warning("DW_OP %x is not supported.\n", op->atom);
		return -ENOTSUP;
		}

		regs = get_arch_regstr(regn);
		if (!regs)
		die("%u exceeds max register number.", regn);
		if (!regs) {
		pr_warning("%u exceeds max register number.\n", regn);
		return -ERANGE;
		}

		tvar->value = xstrdup(regs);
		if (ref) {
		tvar->ref = xzalloc(sizeof(struct kprobe_trace_arg_ref));
		tvar->ref->offset = (long)offs;
		}
		return 0;
		}

		static void convert_variable_type(Dwarf_Die *vr_die,
		static int convert_variable_type(Dwarf_Die *vr_die,
		struct kprobe_trace_arg *targ)
		{
		Dwarf_Die type;
		char buf[16];
		int ret;

		if (die_get_real_type(vr_die, &type) == NULL)
		die("Failed to get a type information of %s.",
		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;
		}

		ret = die_get_byte_size(&type) * 8;
		if (ret) {
		/* Check the bitwidth */
		if (ret > MAX_BASIC_TYPE_BITS) {
		pr_warning(" Warning: %s exceeds max-bitwidth."
		pr_info("%s exceeds max-bitwidth."
		" Cut down to %d bits.\n",
		dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
		ret = MAX_BASIC_TYPE_BITS;
		@@ -456,13 +454,19 @@ static void convert_variable_type(Dwarf_Die *vr_die,

		ret = snprintf(buf, 16, "%c%d",
		die_is_signed_type(&type) ? 's' : 'u', ret);
		if (ret < 0 \|\| ret >= 16)
		die("Failed to convert variable type.");
		if (ret < 0 \|\| ret >= 16) {
		if (ret >= 16)
		ret = -E2BIG;
		pr_warning("Failed to convert variable type: %s\n",
		strerror(-ret));
		return ret;
		}
		targ->type = xstrdup(buf);
		}
		return 0;
		}

		static void convert_variable_fields(Dwarf_Die vr_die, const char varname,
		static int convert_variable_fields(Dwarf_Die vr_die, const char varname,
		struct perf_probe_arg_field *field,
		struct kprobe_trace_arg_ref **ref_ptr,
		Dwarf_Die *die_mem)
		@@ -473,21 +477,28 @@ static void convert_variable_fields(Dwarf_Die vr_die, const char varname,
		Dwarf_Word offs;

		pr_debug("converting %s in %s\n", field->name, varname);
		if (die_get_real_type(vr_die, &type) == NULL)
		die("Failed to get a type information of %s.", varname);
		if (die_get_real_type(vr_die, &type) == NULL) {
		pr_warning("Failed to get the type of %s.\n", varname);
		return -ENOENT;
		}

		/* Check the pointer and dereference */
		if (dwarf_tag(&type) == DW_TAG_pointer_type) {
		if (!field->ref)
		die("Semantic error: %s must be referred by '->'",
		if (!field->ref) {
		pr_err("Semantic error: %s must be referred by '->'\n",
		field->name);
		return -EINVAL;
		}
		/* Get the type pointed by this pointer */
		if (die_get_real_type(&type, &type) == NULL)
		die("Failed to get a type information of %s.", varname);

		if (die_get_real_type(&type, &type) == NULL) {
		pr_warning("Failed to get the type of %s.\n", varname);
		return -ENOENT;
		}
		/* Verify it is a data structure */
		if (dwarf_tag(&type) != DW_TAG_structure_type)
		die("%s is not a data structure.", varname);
		if (dwarf_tag(&type) != DW_TAG_structure_type) {
		pr_warning("%s is not a data structure.\n", varname);
		return -EINVAL;
		}

		ref = xzalloc(sizeof(struct kprobe_trace_arg_ref));
		if (*ref_ptr)
		@@ -496,34 +507,46 @@ static void convert_variable_fields(Dwarf_Die vr_die, const char varname,
		*ref_ptr = ref;
		} else {
		/* Verify it is a data structure */
		if (dwarf_tag(&type) != DW_TAG_structure_type)
		die("%s is not a data structure.", varname);

		if (field->ref)
		die("Semantic error: %s must be referred by '.'",
		if (dwarf_tag(&type) != DW_TAG_structure_type) {
		pr_warning("%s is not a data structure.\n", varname);
		return -EINVAL;
		}
		if (field->ref) {
		pr_err("Semantic error: %s must be referred by '.'\n",
		field->name);
		if (!ref)
		die("Structure on a register is not supported yet.");
		return -EINVAL;
		}
		if (!ref) {
		pr_warning("Structure on a register is not "
		"supported yet.\n");
		return -ENOTSUP;
		}
		}

		if (die_find_member(&type, field->name, die_mem) == NULL)
		die("%s(tyep:%s) has no member %s.", varname,
		if (die_find_member(&type, field->name, die_mem) == NULL) {
		pr_warning("%s(tyep:%s) has no member %s.\n", varname,
		dwarf_diename(&type), field->name);
		return -EINVAL;
		}

		/* Get the offset of the field */
		if (dwarf_attr(die_mem, DW_AT_data_member_location, &attr) == NULL \|\|
		dwarf_formudata(&attr, &offs) != 0)
		die("Failed to get the offset of %s.", field->name);
		dwarf_formudata(&attr, &offs) != 0) {
		pr_warning("Failed to get the offset of %s.\n", field->name);
		return -ENOENT;
		}
		ref->offset += (long)offs;

		/* Converting next field */
		if (field->next)
		convert_variable_fields(die_mem, field->name, field->next,
		&ref, die_mem);
		return convert_variable_fields(die_mem, field->name,
		field->next, &ref, die_mem);
		else
		return 0;
		}

		/* Show a variables in kprobe event format */
		static void convert_variable(Dwarf_Die vr_die, struct probe_finder pf)
		static int convert_variable(Dwarf_Die vr_die, struct probe_finder pf)
		{
		Dwarf_Attribute attr;
		Dwarf_Die die_mem;
		@@ -538,28 +561,30 @@ static void convert_variable(Dwarf_Die vr_die, struct probe_finder pf)
		if (ret <= 0 \|\| nexpr == 0)
		goto error;

		convert_location(expr, pf);

		if (pf->pvar->field) {
		convert_variable_fields(vr_die, pf->pvar->var,
		ret = convert_location(expr, pf);
		if (ret == 0 && pf->pvar->field) {
		ret = convert_variable_fields(vr_die, pf->pvar->var,
		pf->pvar->field, &pf->tvar->ref,
		&die_mem);
		vr_die = &die_mem;
		}
		if (ret == 0) {
		if (pf->pvar->type)
		pf->tvar->type = xstrdup(pf->pvar->type);
		else
		convert_variable_type(vr_die, pf->tvar);
		ret = convert_variable_type(vr_die, pf->tvar);
		}
		/* expr will be cached in libdw. Don't free it. /
		return ;
		return ret;
		error:
		/* TODO: Support const_value */
		die("Failed to find the location of %s at this address.\n"
		" Perhaps, it has been optimized out.", pf->pvar->var);
		pr_err("Failed to find the location of %s at this address.\n"
		" Perhaps, it has been optimized out.\n", pf->pvar->var);
		return -ENOENT;
		}

		/* Find a variable in a subprogram die */
		static void find_variable(Dwarf_Die sp_die, struct probe_finder pf)
		static int find_variable(Dwarf_Die sp_die, struct probe_finder pf)
		{
		Dwarf_Die vr_die;
		char buf[32], *ptr;
		@@ -578,19 +603,22 @@ static void find_variable(Dwarf_Die sp_die, struct probe_finder pf)
		if (!is_c_varname(pf->pvar->var)) {
		/* Copy raw parameters */
		pf->tvar->value = xstrdup(pf->pvar->var);
		} else {
		return 0;
		}

		pr_debug("Searching '%s' variable in context.\n",
		pf->pvar->var);
		/* Search child die for local variables and parameters. */
		if (!die_find_variable(sp_die, pf->pvar->var, &vr_die))
		die("Failed to find '%s' in this function.",
		if (!die_find_variable(sp_die, pf->pvar->var, &vr_die)) {
		pr_warning("Failed to find '%s' in this function.\n",
		pf->pvar->var);
		convert_variable(&vr_die, pf);
		return -ENOENT;
		}
		return convert_variable(&vr_die, pf);
		}

		/* Show a probe point to output buffer */
		static void convert_probe_point(Dwarf_Die sp_die, struct probe_finder pf)
		static int convert_probe_point(Dwarf_Die sp_die, struct probe_finder pf)
		{
		struct kprobe_trace_event *tev;
		Dwarf_Addr eaddr;
		@@ -600,22 +628,31 @@ static void convert_probe_point(Dwarf_Die sp_die, struct probe_finder pf)
		Dwarf_Attribute fb_attr;
		size_t nops;

		if (pf->ntevs == MAX_PROBES)
		die("Too many( > %d) probe point found.\n", MAX_PROBES);
		if (pf->ntevs == MAX_PROBES) {
		pr_warning("Too many( > %d) probe point found.\n", MAX_PROBES);
		return -ERANGE;
		}
		tev = &pf->tevs[pf->ntevs++];

		/* If no real subprogram, find a real one */
		if (!sp_die \|\| dwarf_tag(sp_die) != DW_TAG_subprogram) {
		sp_die = die_find_real_subprogram(&pf->cu_die,
		pf->addr, &die_mem);
		if (!sp_die)
		die("Probe point is not found in subprograms.");
		if (!sp_die) {
		pr_warning("Failed to find probe point in any "
		"functions.\n");
		return -ENOENT;
		}
		}

		/* Copy the name of probe point */
		name = dwarf_diename(sp_die);
		if (name) {
		dwarf_entrypc(sp_die, &eaddr);
		if (dwarf_entrypc(sp_die, &eaddr) != 0) {
		pr_warning("Failed to get entry pc of %s\n",
		dwarf_diename(sp_die));
		return -ENOENT;
		}
		tev->point.symbol = xstrdup(name);
		tev->point.offset = (unsigned long)(pf->addr - eaddr);
		} else
		@@ -633,9 +670,12 @@ static void convert_probe_point(Dwarf_Die sp_die, struct probe_finder pf)
		} else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
		pf->cfi != NULL) {
		Dwarf_Frame *frame;
		ret = dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame);
		DIE_IF(ret != 0);
		dwarf_frame_cfa(frame, &pf->fb_ops, &nops);
		if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 \|\|
		dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
		pr_warning("Failed to get CFA on 0x%jx\n",
		(uintmax_t)pf->addr);
		return -ENOENT;
		}
		}

		/* Find each argument */
		@@ -644,45 +684,53 @@ static void convert_probe_point(Dwarf_Die sp_die, struct probe_finder pf)
		for (i = 0; i < pf->pev->nargs; i++) {
		pf->pvar = &pf->pev->args[i];
		pf->tvar = &tev->args[i];
		find_variable(sp_die, pf);
		ret = find_variable(sp_die, pf);
		if (ret != 0)
		return ret;
		}

		/* pf->fb_ops will be cached in libdw. Don't free it. /
		pf->fb_ops = NULL;
		return 0;
		}

		/* Find probe point from its line number */
		static void find_probe_point_by_line(struct probe_finder *pf)
		static int find_probe_point_by_line(struct probe_finder *pf)
		{
		Dwarf_Lines *lines;
		Dwarf_Line *line;
		size_t nlines, i;
		Dwarf_Addr addr;
		int lineno;
		int ret;
		int ret = 0;

		ret = dwarf_getsrclines(&pf->cu_die, &lines, &nlines);
		DIE_IF(ret != 0);
		if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
		pr_warning("No source lines found in this CU.\n");
		return -ENOENT;
		}

		for (i = 0; i < nlines; i++) {
		for (i = 0; i < nlines && ret == 0; i++) {
		line = dwarf_onesrcline(lines, i);
		dwarf_lineno(line, &lineno);
		if (lineno != pf->lno)
		if (dwarf_lineno(line, &lineno) != 0 \|\|
		lineno != pf->lno)
		continue;

		/* TODO: Get fileno from line, but how? */
		if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
		continue;

		ret = dwarf_lineaddr(line, &addr);
		DIE_IF(ret != 0);
		if (dwarf_lineaddr(line, &addr) != 0) {
		pr_warning("Failed to get the address of the line.\n");
		return -ENOENT;
		}
		pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
		(int)i, lineno, (uintmax_t)addr);
		pf->addr = addr;

		convert_probe_point(NULL, pf);
		ret = convert_probe_point(NULL, pf);
		/* Continuing, because target line might be inlined. */
		}
		return ret;
		}

		/* Find lines which match lazy pattern */
		@@ -690,15 +738,27 @@ static int find_lazy_match_lines(struct list_head *head,
		const char fname, const char pat)
		{
		char fbuf, p1, *p2;
		int fd, line, nlines = 0;
		int fd, ret, line, nlines = 0;
		struct stat st;

		fd = open(fname, O_RDONLY);
		if (fd < 0)
		die("failed to open %s", fname);
		DIE_IF(fstat(fd, &st) < 0);
		if (fd < 0) {
		pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
		return fd;
		}

		ret = fstat(fd, &st);
		if (ret < 0) {
		pr_warning("Failed to get the size of %s: %s\n",
		fname, strerror(errno));
		return ret;
		}
		fbuf = xmalloc(st.st_size + 2);
		DIE_IF(read(fd, fbuf, st.st_size) < 0);
		ret = read(fd, fbuf, st.st_size);
		if (ret < 0) {
		pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
		return ret;
		}
		close(fd);
		fbuf[st.st_size] = '\n'; /* Dummy line */
		fbuf[st.st_size + 1] = '\0';
		@@ -718,7 +778,7 @@ static int find_lazy_match_lines(struct list_head *head,
		}

		/* Find probe points from lazy pattern */
		static void find_probe_point_lazy(Dwarf_Die sp_die, struct probe_finder pf)
		static int find_probe_point_lazy(Dwarf_Die sp_die, struct probe_finder pf)
		{
		Dwarf_Lines *lines;
		Dwarf_Line *line;
		@@ -726,31 +786,40 @@ static void find_probe_point_lazy(Dwarf_Die sp_die, struct probe_finder pf)
		Dwarf_Addr addr;
		Dwarf_Die die_mem;
		int lineno;
		int ret;
		int ret = 0;

		if (list_empty(&pf->lcache)) {
		/* Matching lazy line pattern */
		ret = find_lazy_match_lines(&pf->lcache, pf->fname,
		pf->pev->point.lazy_line);
		if (ret <= 0)
		die("No matched lines found in %s.", pf->fname);
		if (ret == 0) {
		pr_debug("No matched lines found in %s.\n", pf->fname);
		return 0;
		} else if (ret < 0)
		return ret;
		}

		ret = dwarf_getsrclines(&pf->cu_die, &lines, &nlines);
		DIE_IF(ret != 0);
		for (i = 0; i < nlines; i++) {
		if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
		pr_warning("No source lines found in this CU.\n");
		return -ENOENT;
		}

		for (i = 0; i < nlines && ret >= 0; i++) {
		line = dwarf_onesrcline(lines, i);

		dwarf_lineno(line, &lineno);
		if (!line_list__has_line(&pf->lcache, lineno))
		if (dwarf_lineno(line, &lineno) != 0 \|\|
		!line_list__has_line(&pf->lcache, lineno))
		continue;

		/* TODO: Get fileno from line, but how? */
		if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
		continue;

		ret = dwarf_lineaddr(line, &addr);
		DIE_IF(ret != 0);
		if (dwarf_lineaddr(line, &addr) != 0) {
		pr_debug("Failed to get the address of line %d.\n",
		lineno);
		continue;
		}
		if (sp_die) {
		/* Address filtering 1: does sp_die include addr? */
		if (!dwarf_haspc(sp_die, addr))
		@@ -764,27 +833,42 @@ static void find_probe_point_lazy(Dwarf_Die sp_die, struct probe_finder pf)
		(int)i, lineno, (unsigned long long)addr);
		pf->addr = addr;

		convert_probe_point(sp_die, pf);
		ret = convert_probe_point(sp_die, pf);
		/* Continuing, because target line might be inlined. */
		}
		/* TODO: deallocate lines, but how? */
		return ret;
		}

		/* Callback parameter with return value */
		struct dwarf_callback_param {
		void *data;
		int retval;
		};

		static int probe_point_inline_cb(Dwarf_Die in_die, void data)
		{
		struct probe_finder pf = (struct probe_finder )data;
		struct dwarf_callback_param *param = data;
		struct probe_finder *pf = param->data;
		struct perf_probe_point *pp = &pf->pev->point;
		Dwarf_Addr addr;

		if (pp->lazy_line)
		find_probe_point_lazy(in_die, pf);
		param->retval = find_probe_point_lazy(in_die, pf);
		else {
		/* Get probe address */
		pf->addr = die_get_entrypc(in_die);
		if (dwarf_entrypc(in_die, &addr) != 0) {
		pr_warning("Failed to get entry pc of %s.\n",
		dwarf_diename(in_die));
		param->retval = -ENOENT;
		return DWARF_CB_ABORT;
		}
		pf->addr = addr;
		pf->addr += pp->offset;
		pr_debug("found inline addr: 0x%jx\n",
		(uintmax_t)pf->addr);

		convert_probe_point(in_die, pf);
		param->retval = convert_probe_point(in_die, pf);
		}

		return DWARF_CB_OK;
		@@ -793,39 +877,53 @@ static int probe_point_inline_cb(Dwarf_Die in_die, void data)
		/* Search function from function name */
		static int probe_point_search_cb(Dwarf_Die sp_die, void data)
		{
		struct probe_finder pf = (struct probe_finder )data;
		struct dwarf_callback_param *param = data;
		struct probe_finder *pf = param->data;
		struct perf_probe_point *pp = &pf->pev->point;

		/* Check tag and diename */
		if (dwarf_tag(sp_die) != DW_TAG_subprogram \|\|
		die_compare_name(sp_die, pp->function) != 0)
		return 0;
		return DWARF_CB_OK;

		pf->fname = dwarf_decl_file(sp_die);
		if (pp->line) { /* Function relative line */
		dwarf_decl_line(sp_die, &pf->lno);
		pf->lno += pp->line;
		find_probe_point_by_line(pf);
		param->retval = find_probe_point_by_line(pf);
		} else if (!dwarf_func_inline(sp_die)) {
		/* Real function */
		if (pp->lazy_line)
		find_probe_point_lazy(sp_die, pf);
		param->retval = find_probe_point_lazy(sp_die, pf);
		else {
		pf->addr = die_get_entrypc(sp_die);
		if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
		pr_warning("Failed to get entry pc of %s.\n",
		dwarf_diename(sp_die));
		param->retval = -ENOENT;
		return DWARF_CB_ABORT;
		}
		pf->addr += pp->offset;
		/* TODO: Check the address in this function */
		convert_probe_point(sp_die, pf);
		param->retval = convert_probe_point(sp_die, pf);
		}
		} else
		} else {
		struct dwarf_callback_param _param = {.data = (void *)pf,
		.retval = 0};
		/* Inlined function: search instances */
		dwarf_func_inline_instances(sp_die, probe_point_inline_cb, pf);
		dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
		&_param);
		param->retval = _param.retval;
		}

		return 1; /* Exit; no same symbol in this CU. */
		return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
		}

		static void find_probe_point_by_func(struct probe_finder *pf)
		static int find_probe_point_by_func(struct probe_finder *pf)
		{
		dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, pf, 0);
		struct dwarf_callback_param _param = {.data = (void *)pf,
		.retval = 0};
		dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
		return _param.retval;
		}

		/* Find kprobe_trace_events specified by perf_probe_event from debuginfo */
		@@ -838,14 +936,18 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
		size_t cuhl;
		Dwarf_Die *diep;
		Dwarf *dbg;
		int ret = 0;

		pf.tevs = xzalloc(sizeof(struct kprobe_trace_event) * MAX_PROBES);
		*tevs = pf.tevs;
		pf.ntevs = 0;

		dbg = dwarf_begin(fd, DWARF_C_READ);
		if (!dbg)
		return -ENOENT;
		if (!dbg) {
		pr_warning("No dwarf info found in the vmlinux - "
		"please rebuild with CONFIG_DEBUG_INFO=y.\n");
		return -EBADF;
		}

		/* Get the call frame information from this dwarf */
		pf.cfi = dwarf_getcfi(dbg);
		@@ -853,7 +955,8 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
		off = 0;
		line_list__init(&pf.lcache);
		/* Loop on CUs (Compilation Unit) */
		while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
		while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
		ret >= 0) {
		/* Get the DIE(Debugging Information Entry) of this CU */
		diep = dwarf_offdie(dbg, off + cuhl, &pf.cu_die);
		if (!diep)
		@@ -867,12 +970,12 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,

		if (!pp->file \|\| pf.fname) {
		if (pp->function)
		find_probe_point_by_func(&pf);
		ret = find_probe_point_by_func(&pf);
		else if (pp->lazy_line)
		find_probe_point_lazy(NULL, &pf);
		ret = find_probe_point_lazy(NULL, &pf);
		else {
		pf.lno = pp->line;
		find_probe_point_by_line(&pf);
		ret = find_probe_point_by_line(&pf);
		}
		}
		off = noff;
		@@ -880,7 +983,7 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
		line_list__free(&pf.lcache);
		dwarf_end(dbg);

		return pf.ntevs;
		return (ret < 0) ? ret : pf.ntevs;
		}

		/* Reverse search */
		@@ -893,10 +996,11 @@ int find_perf_probe_point(int fd, unsigned long addr,
		Dwarf_Addr laddr, eaddr;
		const char *tmp;
		int lineno, ret = 0;
		bool found = false;

		dbg = dwarf_begin(fd, DWARF_C_READ);
		if (!dbg)
		return -ENOENT;
		return -EBADF;

		/* Find cu die */
		if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) {
		@@ -907,82 +1011,87 @@ int find_perf_probe_point(int fd, unsigned long addr,
		/* Find a corresponding line */
		line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
		if (line) {
		dwarf_lineaddr(line, &laddr);
		if ((Dwarf_Addr)addr == laddr) {
		dwarf_lineno(line, &lineno);
		ppt->line = lineno;

		if (dwarf_lineaddr(line, &laddr) == 0 &&
		(Dwarf_Addr)addr == laddr &&
		dwarf_lineno(line, &lineno) == 0) {
		tmp = dwarf_linesrc(line, NULL, NULL);
		DIE_IF(!tmp);
		if (tmp) {
		ppt->line = lineno;
		ppt->file = xstrdup(tmp);
		ret = 1;
		found = true;
		}
		}
		}

		/* Find a corresponding function */
		if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
		tmp = dwarf_diename(&spdie);
		if (!tmp)
		if (!tmp \|\| dwarf_entrypc(&spdie, &eaddr) != 0)
		goto end;

		dwarf_entrypc(&spdie, &eaddr);
		if (!lineno) {
		/* We don't have a line number, let's use offset */
		ppt->function = xstrdup(tmp);
		ppt->offset = addr - (unsigned long)eaddr;
		ret = 1;
		goto end;
		}
		if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr, &indie)) {
		if (ppt->line) {
		if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
		&indie)) {
		/* addr in an inline function */
		tmp = dwarf_diename(&indie);
		if (!tmp)
		goto end;
		dwarf_decl_line(&indie, &lineno);
		ret = dwarf_decl_line(&indie, &lineno);
		} else {
		if (eaddr == addr) /* No offset: function entry */
		if (eaddr == addr) { /* Function entry */
		lineno = ppt->line;
		else
		dwarf_decl_line(&spdie, &lineno);
		ret = 0;
		} else
		ret = dwarf_decl_line(&spdie, &lineno);
		}
		if (ret == 0) {
		/* Make a relative line number */
		ppt->line -= lineno;
		goto found;
		}
		}
		/* We don't have a line number, let's use offset */
		ppt->offset = addr - (unsigned long)eaddr;
		found:
		ppt->function = xstrdup(tmp);
		ppt->line -= lineno; /* Make a relative line number */
		found = true;
		}

		end:
		dwarf_end(dbg);
		if (ret >= 0)
		ret = found ? 1 : 0;
		return ret;
		}


		/* Find line range from its line number */
		static void find_line_range_by_line(Dwarf_Die sp_die, struct line_finder lf)
		static int find_line_range_by_line(Dwarf_Die sp_die, struct line_finder lf)
		{
		Dwarf_Lines *lines;
		Dwarf_Line *line;
		size_t nlines, i;
		Dwarf_Addr addr;
		int lineno;
		int ret;
		const char *src;
		Dwarf_Die die_mem;

		line_list__init(&lf->lr->line_list);
		ret = dwarf_getsrclines(&lf->cu_die, &lines, &nlines);
		DIE_IF(ret != 0);
		if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
		pr_warning("No source lines found in this CU.\n");
		return -ENOENT;
		}

		for (i = 0; i < nlines; i++) {
		line = dwarf_onesrcline(lines, i);
		ret = dwarf_lineno(line, &lineno);
		DIE_IF(ret != 0);
		if (lf->lno_s > lineno \|\| lf->lno_e < lineno)
		if (dwarf_lineno(line, &lineno) != 0 \|\|
		(lf->lno_s > lineno \|\| lf->lno_e < lineno))
		continue;

		if (sp_die) {
		/* Address filtering 1: does sp_die include addr? */
		ret = dwarf_lineaddr(line, &addr);
		DIE_IF(ret != 0);
		if (!dwarf_haspc(sp_die, addr))
		if (dwarf_lineaddr(line, &addr) != 0 \|\|
		!dwarf_haspc(sp_die, addr))
		continue;

		/* Address filtering 2: No child include addr? */
		@@ -1007,18 +1116,22 @@ static void find_line_range_by_line(Dwarf_Die sp_die, struct line_finder lf)
		free(lf->lr->path);
		lf->lr->path = NULL;
		}
		return lf->found;
		}

		static int line_range_inline_cb(Dwarf_Die in_die, void data)
		{
		find_line_range_by_line(in_die, (struct line_finder *)data);
		struct dwarf_callback_param *param = data;

		param->retval = find_line_range_by_line(in_die, param->data);
		return DWARF_CB_ABORT; /* No need to find other instances */
		}

		/* Search function from function name */
		static int line_range_search_cb(Dwarf_Die sp_die, void data)
		{
		struct line_finder lf = (struct line_finder )data;
		struct dwarf_callback_param *param = data;
		struct line_finder *lf = param->data;
		struct line_range *lr = lf->lr;

		if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
		@@ -1033,38 +1146,47 @@ static int line_range_search_cb(Dwarf_Die sp_die, void data)
		lf->lno_e = lr->offset + lr->end;
		lr->start = lf->lno_s;
		lr->end = lf->lno_e;
		if (dwarf_func_inline(sp_die))
		if (dwarf_func_inline(sp_die)) {
		struct dwarf_callback_param _param;
		_param.data = (void *)lf;
		_param.retval = 0;
		dwarf_func_inline_instances(sp_die,
		line_range_inline_cb, lf);
		else
		find_line_range_by_line(sp_die, lf);
		return 1;
		line_range_inline_cb,
		&_param);
		param->retval = _param.retval;
		} else
		param->retval = find_line_range_by_line(sp_die, lf);
		return DWARF_CB_ABORT;
		}
		return 0;
		return DWARF_CB_OK;
		}

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

		int find_line_range(int fd, struct line_range *lr)
		{
		struct line_finder lf = {.lr = lr, .found = 0};
		int ret;
		int ret = 0;
		Dwarf_Off off = 0, noff;
		size_t cuhl;
		Dwarf_Die *diep;
		Dwarf *dbg;

		dbg = dwarf_begin(fd, DWARF_C_READ);
		if (!dbg)
		return -ENOENT;
		if (!dbg) {
		pr_warning("No dwarf info found in the vmlinux - "
		"please rebuild with CONFIG_DEBUG_INFO=y.\n");
		return -EBADF;
		}

		/* Loop on CUs (Compilation Unit) */
		while (!lf.found) {
		ret = dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL);
		if (ret != 0)
		while (!lf.found && ret >= 0) {
		if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
		break;

		/* Get the DIE(Debugging Information Entry) of this CU */
		@@ -1080,20 +1202,21 @@ int find_line_range(int fd, struct line_range *lr)

		if (!lr->file \|\| lf.fname) {
		if (lr->function)
		find_line_range_by_func(&lf);
		ret = find_line_range_by_func(&lf);
		else {
		lf.lno_s = lr->start;
		if (!lr->end)
		lf.lno_e = INT_MAX;
		else
		lf.lno_e = lr->end;
		find_line_range_by_line(NULL, &lf);
		ret = find_line_range_by_line(NULL, &lf);
		}
		}
		off = noff;
		}
		pr_debug("path: %lx\n", (unsigned long)lr->path);
		dwarf_end(dbg);
		return lf.found;

		return (ret < 0) ? ret : lf.found;
		}