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Commit 5a6f6314 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Arnaldo Carvalho de Melo
Browse files

perf probe: Show source-level or symbol-level info for uprobes 



Show source-level or symbol-level information for uprobe events.

Without this change;
  # ./perf probe -l
    probe_perf:dso__load_vmlinux (on 0x000000000006d110 in /kbuild/ksrc/linux-3/tools/perf/perf)

With this change;
  # ./perf probe -l
    probe_perf:dso__load_vmlinux (on dso__load_vmlinux@util/symbol.c in /kbuild/ksrc/linux-3/tools/perf/perf)

Changes from v2:
 - Update according to previous patches.

Changes from v1:
 - Rewrite the code based on new series.

Signed-off-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20140206053223.29635.51280.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 8f33f7de

tools/perf/util/probe-event.c

+144 −83
Original line number Diff line number Diff line
@@ -249,34 +249,6 @@ static int convert_exec_to_group(const char *exec, char **result) 
	return ret;

}



static int convert_to_perf_probe_point(struct probe_trace_point *tp,

					struct perf_probe_point *pp)

{

	struct symbol *sym;

	struct map *map;

	u64 addr = kernel_get_symbol_address_by_name(tp->symbol, true);



	if (addr) {

		addr += tp->offset;

		sym = __find_kernel_function(addr, &map);

		if (!sym)

			goto failed;

		pp->function = strdup(sym->name);

		pp->offset = addr - map->unmap_ip(map, sym->start);

	} else {

failed:

		pp->function = strdup(tp->symbol);

		pp->offset = tp->offset;

	}



	if (pp->function == NULL)

		return -ENOMEM;



	pp->retprobe = tp->retprobe;



	return 0;

}



#ifdef HAVE_DWARF_SUPPORT

/* Open new debuginfo of given module */

static struct debuginfo *open_debuginfo(const char *module)
@@ -298,44 +270,6 @@ static struct debuginfo *open_debuginfo(const char *module) 
	return debuginfo__new(path);

}



/*

 * Convert trace point to probe point with debuginfo

 * Currently only handles kprobes.

 */

static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp,

					struct perf_probe_point *pp)

{

	u64 addr = 0;

	int ret = -ENOENT;

	struct debuginfo *dinfo;



	addr = kernel_get_symbol_address_by_name(tp->symbol, false);

	if (addr) {

		addr += tp->offset;

		pr_debug("try to find %s+%ld@%" PRIx64 "\n", tp->symbol,

			 tp->offset, addr);



		dinfo = open_debuginfo(tp->module);

		if (dinfo) {

			ret = debuginfo__find_probe_point(dinfo,

						 (unsigned long)addr, pp);

			debuginfo__delete(dinfo);

		} else {

			pr_debug("Failed to open debuginfo at 0x%" PRIx64 "\n",

				 addr);

			ret = -ENOENT;

		}

	}

	if (ret <= 0) {

		pr_debug("Failed to find corresponding probes from "

			 "debuginfo. Use kprobe event information.\n");

		return convert_to_perf_probe_point(tp, pp);

	}

	pp->retprobe = tp->retprobe;



	return 0;

}



static int get_text_start_address(const char *exec, unsigned long *address)

{

	Elf *elf;
@@ -364,6 +298,57 @@ static int get_text_start_address(const char *exec, unsigned long *address) 
	return ret;

}



/*

 * Convert trace point to probe point with debuginfo

 */

static int find_perf_probe_point_from_dwarf(struct probe_trace_point *tp,

					    struct perf_probe_point *pp,

					    bool is_kprobe)

{

	struct debuginfo *dinfo = NULL;

	unsigned long stext = 0;

	u64 addr = tp->address;

	int ret = -ENOENT;



	/* convert the address to dwarf address */

	if (!is_kprobe) {

		if (!addr) {

			ret = -EINVAL;

			goto error;

		}

		ret = get_text_start_address(tp->module, &stext);

		if (ret < 0)

			goto error;

		addr += stext;

	} else {

		addr = kernel_get_symbol_address_by_name(tp->symbol, false);

		if (addr == 0)

			goto error;

		addr += tp->offset;

	}



	pr_debug("try to find information at %" PRIx64 " in %s\n", addr,

		 tp->module ? : "kernel");



	dinfo = open_debuginfo(tp->module);

	if (dinfo) {

		ret = debuginfo__find_probe_point(dinfo,

						 (unsigned long)addr, pp);

		debuginfo__delete(dinfo);

	} else {

		pr_debug("Failed to open debuginfo at 0x%" PRIx64 "\n", addr);

		ret = -ENOENT;

	}



	if (ret > 0) {

		pp->retprobe = tp->retprobe;

		return 0;

	}

error:

	pr_debug("Failed to find corresponding probes from debuginfo.\n");

	return ret ? : -ENOENT;

}



static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,

					  int ntevs, const char *exec)

{
@@ -815,10 +800,12 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs, 


#else	/* !HAVE_DWARF_SUPPORT */



static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp,

					struct perf_probe_point *pp)

static int

find_perf_probe_point_from_dwarf(struct probe_trace_point *tp __maybe_unused,

				 struct perf_probe_point *pp __maybe_unused,

				 bool is_kprobe __maybe_unused)

{

	return convert_to_perf_probe_point(tp, pp);

	return -ENOSYS;

}



static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
@@ -1343,6 +1330,10 @@ static int parse_probe_trace_command(const char *cmd, 
	} else

		p = argv[1];

	fmt1_str = strtok_r(p, "+", &fmt);

	if (fmt1_str[0] == '0')	/* only the address started with 0x */

		tp->address = strtoul(fmt1_str, NULL, 0);

	else {

		/* Only the symbol-based probe has offset */

		tp->symbol = strdup(fmt1_str);

		if (tp->symbol == NULL) {

			ret = -ENOMEM;
@@ -1353,6 +1344,7 @@ static int parse_probe_trace_command(const char *cmd, 
			tp->offset = 0;

		else

			tp->offset = strtoul(fmt2_str, NULL, 10);

	}



	tev->nargs = argc - 2;

	tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
@@ -1623,6 +1615,79 @@ char *synthesize_probe_trace_command(struct probe_trace_event *tev) 
	return NULL;

}



static int find_perf_probe_point_from_map(struct probe_trace_point *tp,

					  struct perf_probe_point *pp,

					  bool is_kprobe)

{

	struct symbol *sym = NULL;

	struct map *map;

	u64 addr;

	int ret = -ENOENT;



	if (!is_kprobe) {

		map = dso__new_map(tp->module);

		if (!map)

			goto out;

		addr = tp->address;

		sym = map__find_symbol(map, addr, NULL);

	} else {

		addr = kernel_get_symbol_address_by_name(tp->symbol, true);

		if (addr) {

			addr += tp->offset;

			sym = __find_kernel_function(addr, &map);

		}

	}

	if (!sym)

		goto out;



	pp->retprobe = tp->retprobe;

	pp->offset = addr - map->unmap_ip(map, sym->start);

	pp->function = strdup(sym->name);

	ret = pp->function ? 0 : -ENOMEM;



out:

	if (map && !is_kprobe) {

		dso__delete(map->dso);

		map__delete(map);

	}



	return ret;

}



static int convert_to_perf_probe_point(struct probe_trace_point *tp,

					struct perf_probe_point *pp,

					bool is_kprobe)

{

	char buf[128];

	int ret;



	ret = find_perf_probe_point_from_dwarf(tp, pp, is_kprobe);

	if (!ret)

		return 0;

	ret = find_perf_probe_point_from_map(tp, pp, is_kprobe);

	if (!ret)

		return 0;



	pr_debug("Failed to find probe point from both of dwarf and map.\n");



	if (tp->symbol) {

		pp->function = strdup(tp->symbol);

		pp->offset = tp->offset;

	} else if (!tp->module && !is_kprobe) {

		ret = e_snprintf(buf, 128, "0x%" PRIx64, (u64)tp->address);

		if (ret < 0)

			return ret;

		pp->function = strdup(buf);

		pp->offset = 0;

	}

	if (pp->function == NULL)

		return -ENOMEM;



	pp->retprobe = tp->retprobe;



	return 0;

}



static int convert_to_perf_probe_event(struct probe_trace_event *tev,

			       struct perf_probe_event *pev, bool is_kprobe)

{
@@ -1636,11 +1701,7 @@ static int convert_to_perf_probe_event(struct probe_trace_event *tev, 
		return -ENOMEM;



	/* Convert trace_point to probe_point */

	if (is_kprobe)

		ret = kprobe_convert_to_perf_probe(&tev->point, &pev->point);

	else

		ret = convert_to_perf_probe_point(&tev->point, &pev->point);



	ret = convert_to_perf_probe_point(&tev->point, &pev->point, is_kprobe);

	if (ret < 0)

		return ret;