perf tools: Read the build-ids from the header layer

Keep the build-ids reading implementation in the data mapping
but move its call to the headers so that we have a better
control on it (offset seeking, size passing, etc..).

Signed-off-by: Frederic Weisbecker <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Arnaldo Carvalho de Melo <[e-mail]>
Cc: Mike Galbraith <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Hitoshi Mitake <[e-mail]>
LKML-Reference: <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>

tools/perf/util/data_map.c

···
 	}
 }
 
-static int perf_header__read_build_ids(const struct perf_header *self,
-				       int input, off_t file_size)
+int perf_header__read_build_ids(const struct perf_header *self,
+				int input, off_t file_size)
 {
 	off_t offset = self->data_offset + self->data_size;
 	struct build_id_event bev;
···
 	if (curr_handler->sample_type_check)
 		if (curr_handler->sample_type_check(sample_type) < 0)
 			exit(-1);
-
-	if (perf_header__has_feat(header, HEADER_BUILD_ID) &&
-	    perf_header__read_build_ids(header, input, input_stat.st_size))
-		pr_debug("failed to read buildids, continuing...\n");
 
 	if (load_kernel(NULL) < 0) {
 		perror("failed to load kernel symbols");

tools/perf/util/data_map.h

···
 			    int full_paths,
 			    int *cwdlen,
 			    char **cwd);
+int perf_header__read_build_ids(const struct perf_header *self,
+				int input, off_t file_size);
 
 #endif

tools/perf/util/header.c

···
 #include "../perf.h"
 #include "trace-event.h"
 #include "symbol.h"
+#include "data_map.h"
+#include "debug.h"
 
 /*
  * Create new perf.data header attribute:
···
 		trace_report(fd);
 		lseek(fd, trace_sec.offset + trace_sec.size, SEEK_SET);
 	}
+
+	if (perf_header__has_feat(self, HEADER_BUILD_ID)) {
+		struct stat input_stat;
+
+		fstat(fd, &input_stat);
+		if (perf_header__read_build_ids(self, fd, input_stat.st_size))
+			pr_debug("failed to read buildids, continuing...\n");
+	}
 };
 
 struct perf_header *perf_header__read(int fd)
···
 
 	memcpy(&self->adds_features, &f_header.adds_features, sizeof(f_header.adds_features));
 
-	perf_header__adds_read(self, fd);
-
 	self->event_offset = f_header.event_types.offset;
 	self->event_size   = f_header.event_types.size;
 
 	self->data_offset = f_header.data.offset;
 	self->data_size   = f_header.data.size;
+
+	perf_header__adds_read(self, fd);
 
 	lseek(fd, self->data_offset, SEEK_SET);