perf symbols: Factor out buildid reading routine
So that we can run it without having a DSO instance.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1257291970-8208-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index ac94d7b..e7c7cdb 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -825,27 +825,27 @@
return err;
}
-#define BUILD_ID_SIZE 128
+#define BUILD_ID_SIZE 20
-static char *dso__read_build_id(struct dso *self)
+int filename__read_build_id(const char *filename, void *bf, size_t size)
{
- int i;
+ int fd, err = -1;
GElf_Ehdr ehdr;
GElf_Shdr shdr;
Elf_Data *build_id_data;
Elf_Scn *sec;
- char *build_id = NULL, *bid;
- unsigned char *raw;
Elf *elf;
- int fd = open(self->long_name, O_RDONLY);
+ if (size < BUILD_ID_SIZE)
+ goto out;
+
+ fd = open(filename, O_RDONLY);
if (fd < 0)
goto out;
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
if (elf == NULL) {
- pr_err("%s: cannot read %s ELF file.\n", __func__,
- self->long_name);
+ pr_err("%s: cannot read %s ELF file.\n", __func__, filename);
goto out_close;
}
@@ -854,29 +854,46 @@
goto out_elf_end;
}
- sec = elf_section_by_name(elf, &ehdr, &shdr, ".note.gnu.build-id", NULL);
+ sec = elf_section_by_name(elf, &ehdr, &shdr,
+ ".note.gnu.build-id", NULL);
if (sec == NULL)
goto out_elf_end;
build_id_data = elf_getdata(sec, NULL);
if (build_id_data == NULL)
goto out_elf_end;
- build_id = malloc(BUILD_ID_SIZE);
+ memcpy(bf, build_id_data->d_buf + 16, BUILD_ID_SIZE);
+ err = BUILD_ID_SIZE;
+out_elf_end:
+ elf_end(elf);
+out_close:
+ close(fd);
+out:
+ return err;
+}
+
+static char *dso__read_build_id(struct dso *self)
+{
+ int i, len;
+ char *build_id = NULL, *bid;
+ unsigned char rawbf[BUILD_ID_SIZE], *raw;
+
+ len = filename__read_build_id(self->long_name, rawbf, sizeof(rawbf));
+ if (len < 0)
+ goto out;
+
+ build_id = malloc(len * 2 + 1);
if (build_id == NULL)
- goto out_elf_end;
- raw = build_id_data->d_buf + 16;
+ goto out;
bid = build_id;
- for (i = 0; i < 20; ++i) {
+ raw = rawbf;
+ for (i = 0; i < len; ++i) {
sprintf(bid, "%02x", *raw);
++raw;
bid += 2;
}
pr_debug2("%s(%s): %s\n", __func__, self->long_name, build_id);
-out_elf_end:
- elf_end(elf);
-out_close:
- close(fd);
out:
return build_id;
}
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 0884330..e0d4a58 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -82,6 +82,8 @@
size_t dso__fprintf(struct dso *self, FILE *fp);
char dso__symtab_origin(const struct dso *self);
+int filename__read_build_id(const char *filename, void *bf, size_t size);
+
int load_kernel(symbol_filter_t filter);
void symbol__init(unsigned int priv_size);