Commit 31f5260a authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge tag 'perf-urgent-for-mingo-4.10-20170117' of... 

Merge tag 'perf-urgent-for-mingo-4.10-20170117' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

 into perf/urgent

Pull 'perf probe' fixes from Arnaldo Carvalho de Melo <acme@redhat.com>

  - Show correct locations for 'perf probe' on modules (Masami Hiramatsu)

  - Correctly handle 'perf probe's on GCC generated functions in modules (Masami Hiramatsu)

Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parents 4e71de79 613f050d

tools/perf/util/probe-event.c

+62 −33
Original line number Diff line number Diff line
@@ -610,6 +610,33 @@ error: 
	return ret ? : -ENOENT;

}



/* Adjust symbol name and address */

static int post_process_probe_trace_point(struct probe_trace_point *tp,

					   struct map *map, unsigned long offs)

{

	struct symbol *sym;

	u64 addr = tp->address + tp->offset - offs;



	sym = map__find_symbol(map, addr);

	if (!sym)

		return -ENOENT;



	if (strcmp(sym->name, tp->symbol)) {

		/* If we have no realname, use symbol for it */

		if (!tp->realname)

			tp->realname = tp->symbol;

		else

			free(tp->symbol);

		tp->symbol = strdup(sym->name);

		if (!tp->symbol)

			return -ENOMEM;

	}

	tp->offset = addr - sym->start;

	tp->address -= offs;



	return 0;

}



/*

 * Rename DWARF symbols to ELF symbols -- gcc sometimes optimizes functions

 * and generate new symbols with suffixes such as .constprop.N or .isra.N
@@ -622,11 +649,9 @@ static int 
post_process_offline_probe_trace_events(struct probe_trace_event *tevs,

					int ntevs, const char *pathname)

{

	struct symbol *sym;

	struct map *map;

	unsigned long stext = 0;

	u64 addr;

	int i;

	int i, ret = 0;



	/* Prepare a map for offline binary */

	map = dso__new_map(pathname);
@@ -636,23 +661,14 @@ post_process_offline_probe_trace_events(struct probe_trace_event *tevs, 
	}



	for (i = 0; i < ntevs; i++) {

		addr = tevs[i].point.address + tevs[i].point.offset - stext;

		sym = map__find_symbol(map, addr);

		if (!sym)

			continue;

		if (!strcmp(sym->name, tevs[i].point.symbol))

			continue;

		/* If we have no realname, use symbol for it */

		if (!tevs[i].point.realname)

			tevs[i].point.realname = tevs[i].point.symbol;

		else

			free(tevs[i].point.symbol);

		tevs[i].point.symbol = strdup(sym->name);

		tevs[i].point.offset = addr - sym->start;

		ret = post_process_probe_trace_point(&tevs[i].point,

						     map, stext);

		if (ret < 0)

			break;

	}

	map__put(map);



	return 0;

	return ret;

}



static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,
@@ -682,18 +698,31 @@ static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs, 
	return ret;

}



static int add_module_to_probe_trace_events(struct probe_trace_event *tevs,

					    int ntevs, const char *module)

static int

post_process_module_probe_trace_events(struct probe_trace_event *tevs,

				       int ntevs, const char *module,

				       struct debuginfo *dinfo)

{

	Dwarf_Addr text_offs = 0;

	int i, ret = 0;

	char *mod_name = NULL;

	struct map *map;



	if (!module)

		return 0;



	mod_name = find_module_name(module);

	map = get_target_map(module, false);

	if (!map || debuginfo__get_text_offset(dinfo, &text_offs, true) < 0) {

		pr_warning("Failed to get ELF symbols for %s\n", module);

		return -EINVAL;

	}



	mod_name = find_module_name(module);

	for (i = 0; i < ntevs; i++) {

		ret = post_process_probe_trace_point(&tevs[i].point,

						map, (unsigned long)text_offs);

		if (ret < 0)

			break;

		tevs[i].point.module =

			strdup(mod_name ? mod_name : module);

		if (!tevs[i].point.module) {
@@ -703,6 +732,8 @@ static int add_module_to_probe_trace_events(struct probe_trace_event *tevs, 
	}



	free(mod_name);

	map__put(map);



	return ret;

}
@@ -760,7 +791,7 @@ arch__post_process_probe_trace_events(struct perf_probe_event *pev __maybe_unuse 
static int post_process_probe_trace_events(struct perf_probe_event *pev,

					   struct probe_trace_event *tevs,

					   int ntevs, const char *module,

					   bool uprobe)

					   bool uprobe, struct debuginfo *dinfo)

{

	int ret;
@@ -768,7 +799,8 @@ static int post_process_probe_trace_events(struct perf_probe_event *pev, 
		ret = add_exec_to_probe_trace_events(tevs, ntevs, module);

	else if (module)

		/* Currently ref_reloc_sym based probe is not for drivers */

		ret = add_module_to_probe_trace_events(tevs, ntevs, module);

		ret = post_process_module_probe_trace_events(tevs, ntevs,

							     module, dinfo);

	else

		ret = post_process_kernel_probe_trace_events(tevs, ntevs);
@@ -812,30 +844,27 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, 
		}

	}



	debuginfo__delete(dinfo);



	if (ntevs > 0) {	/* Succeeded to find trace events */

		pr_debug("Found %d probe_trace_events.\n", ntevs);

		ret = post_process_probe_trace_events(pev, *tevs, ntevs,

						pev->target, pev->uprobes);

					pev->target, pev->uprobes, dinfo);

		if (ret < 0 || ret == ntevs) {

			pr_debug("Post processing failed or all events are skipped. (%d)\n", ret);

			clear_probe_trace_events(*tevs, ntevs);

			zfree(tevs);

		}

		if (ret != ntevs)

			return ret < 0 ? ret : ntevs;

			ntevs = 0;

		/* Fall through */

		}

	}



	debuginfo__delete(dinfo);



	if (ntevs == 0)	{	/* No error but failed to find probe point. */

		pr_warning("Probe point '%s' not found.\n",

			   synthesize_perf_probe_point(&pev->point));

		return -ENOENT;

	}

	} else if (ntevs < 0) {

		/* Error path : ntevs < 0 */

		pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs);

	if (ntevs < 0) {

		if (ntevs == -EBADF)

			pr_warning("Warning: No dwarf info found in the vmlinux - "

				"please rebuild kernel with CONFIG_DEBUG_INFO=y.\n");

tools/perf/util/probe-finder.c

+7 −8
Original line number Diff line number Diff line
@@ -1501,7 +1501,8 @@ int debuginfo__find_available_vars_at(struct debuginfo *dbg, 
}



/* For the kernel module, we need a special code to get a DIE */

static int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs)

int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs,

				bool adjust_offset)

{

	int n, i;

	Elf32_Word shndx;
@@ -1530,6 +1531,8 @@ static int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs) 
			if (!shdr)

				return -ENOENT;

			*offs = shdr->sh_addr;

			if (adjust_offset)

				*offs -= shdr->sh_offset;

		}

	}

	return 0;
@@ -1543,16 +1546,12 @@ int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr, 
	Dwarf_Addr _addr = 0, baseaddr = 0;

	const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;

	int baseline = 0, lineno = 0, ret = 0;

	bool reloc = false;



retry:

	/* We always need to relocate the address for aranges */

	if (debuginfo__get_text_offset(dbg, &baseaddr, false) == 0)

		addr += baseaddr;

	/* Find cu die */

	if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) {

		if (!reloc && debuginfo__get_text_offset(dbg, &baseaddr) == 0) {

			addr += baseaddr;

			reloc = true;

			goto retry;

		}

		pr_warning("Failed to find debug information for address %lx\n",

			   addr);

		ret = -EINVAL;

tools/perf/util/probe-finder.h

+3 −0
Original line number Diff line number Diff line
@@ -46,6 +46,9 @@ int debuginfo__find_trace_events(struct debuginfo *dbg, 
int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,

				struct perf_probe_point *ppt);



int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs,

			       bool adjust_offset);



/* Find a line range */

int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr);

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