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Commit f1617b40 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo Committed by Ingo Molnar
Browse files

perf symbols: Record the build_ids of kernel modules too 



[root@doppio linux-2.6-tip]# perf record -a sleep 2s;perf
buildid-list|tail [ perf record: Woken up 1 times to write data
] [ perf record: Captured and wrote 0.162 MB perf.data (~7078
samples) ] 881588fa57b3c1696bc91e5e804a11304f093535 [cfg80211]
4d47ce1da9d16bad00c962c072451b7c681e82df [snd_page_alloc]
5146377e89a7caac617f9782f1a02e46263d3a31 [rfkill]
2153b937bff0d345fea83b63a2e1d3138569f83d [i915]
4e6fb1bb97362e3ee4d306988b9ad6912d5fb9ae [drm_kms_helper]
f56ef2bf853e3a798f0d8d51f797622e5dc4420e [drm]
b0d157a3b5c4e017329ffc07c64623cd6ad65e95 [i2c_algo_bit]
8125374b905ef9fa8b65d98e166b008ad952f198 [i2c_core]
fc875c6e5a90e7b915e9d445d0efc859e1b2678c [video]
4b43c5006589f977e9762fdfc7ac1a92b72fca52 [output]
[root@doppio linux-2.6-tip]#

elfutils libdwfl/linux-kernel-modules.c was used as reference,
as suggested by Roland McGrath.

Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1258582853-8579-3-git-send-email-acme@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent e30a3d12

tools/perf/util/header.c

+5 −0
Original line number Diff line number Diff line
@@ -241,6 +241,11 @@ perf_header__adds_write(struct perf_header *self, int fd) 


		buildid_sec = &feat_sec[idx++];



		/*

		 * Read the list of loaded modules with its build_ids

		 */

		dsos__load_modules();



		/* Write build-ids */

		buildid_sec->offset = lseek(fd, 0, SEEK_CUR);

		if (dsos__write_buildid_table(fd) < 0)

tools/perf/util/symbol.c

+52 −1
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <libelf.h>

#include <gelf.h>

#include <elf.h>

#include <limits.h>

#include <sys/utsname.h>



enum dso_origin {
@@ -943,6 +944,50 @@ int filename__read_build_id(const char *filename, void *bf, size_t size) 
	return err;

}



int sysfs__read_build_id(const char *filename, void *build_id, size_t size)

{

	int fd, err = -1;



	if (size < BUILD_ID_SIZE)

		goto out;



	fd = open(filename, O_RDONLY);

	if (fd < 0)

		goto out;



	while (1) {

		char bf[BUFSIZ];

		GElf_Nhdr nhdr;

		int namesz, descsz;



		if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))

			break;



		namesz = (nhdr.n_namesz + 3) & -4U;

		descsz = (nhdr.n_descsz + 3) & -4U;

		if (nhdr.n_type == NT_GNU_BUILD_ID &&

		    nhdr.n_namesz == sizeof("GNU")) {

			if (read(fd, bf, namesz) != namesz)

				break;

			if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {

				if (read(fd, build_id,

				    BUILD_ID_SIZE) == BUILD_ID_SIZE) {

					err = 0;

					break;

				}

			} else if (read(fd, bf, descsz) != descsz)

				break;

		} else {

			int n = namesz + descsz;

			if (read(fd, bf, n) != n)

				break;

		}

	}

	close(fd);

out:

	return err;

}



char dso__symtab_origin(const struct dso *self)

{

	static const char origin[] = {
@@ -1218,7 +1263,7 @@ static struct map *map__new2(u64 start, struct dso *dso) 
	return self;

}



static int dsos__load_modules(void)

int dsos__load_modules(void)

{

	char *line = NULL;

	size_t n;
@@ -1268,6 +1313,12 @@ static int dsos__load_modules(void) 
			goto out_delete_line;

		}



		snprintf(name, sizeof(name),

			 "/sys/module/%s/notes/.note.gnu.build-id", line);

		if (sysfs__read_build_id(name, dso->build_id,

					 sizeof(dso->build_id)) == 0)

			dso->has_build_id = true;



		dso->origin = DSO__ORIG_KMODULE;

		kernel_maps__insert(map);

		dsos__add(dso);

tools/perf/util/symbol.h

+2 −0
Original line number Diff line number Diff line
@@ -78,6 +78,7 @@ void dso__delete(struct dso *self); 
struct symbol *dso__find_symbol(struct dso *self, u64 ip);



int dsos__load_kernel(const char *vmlinux, symbol_filter_t filter, int modules);

int dsos__load_modules(void);

struct dso *dsos__findnew(const char *name);

int dso__load(struct dso *self, struct map *map, symbol_filter_t filter);

void dsos__fprintf(FILE *fp);
@@ -89,6 +90,7 @@ char dso__symtab_origin(const struct dso *self); 
void dso__set_build_id(struct dso *self, void *build_id);



int filename__read_build_id(const char *filename, void *bf, size_t size);

int sysfs__read_build_id(const char *filename, void *bf, size_t size);

bool dsos__read_build_ids(void);

int build_id__sprintf(u8 *self, int len, char *bf);