perf machine: Add pointer to sample's environment

The 'struct machine' represents the machine where the samples were/are
being collected, and we also have a 'struct perf_env' with extra details
about such machine, that we were collecting at 'perf.data' creation time
but we also needed when no perf.data file is being used, such as in
'perf top'.

So, get those structs closer together, as they provide a bigger picture
of the sample's environment.

In 'perf session', when the file argument is NULL, we can assume that
the tool is sampling the running machine, so point machine->env to
the global put in place in previous patches, while set it to the
perf_header.env one when reading from a file.

This paves the way for machine->env to be used in
perf_event__preprocess_sample to populate addr_location.socket.
Tested-by: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-2ajotl0khscutm68exictoy9@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/header.c

@@ -2564,6 +2564,7 @@ int perf_session__read_header(struct perf_session *session)
 		return -ENOMEM;
 
 	session->evlist->env = &header->env;
+	session->machines.host.env = &header->env;
 	if (perf_data_file__is_pipe(file))
 		return perf_header__read_pipe(session);
 

tools/perf/util/machine.c

@@ -35,6 +35,7 @@ int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
 	machine->last_match = NULL;
 
 	machine->vdso_info = NULL;
+	machine->env = NULL;
 
 	machine->pid = pid;
 

tools/perf/util/machine.h

@@ -34,6 +34,7 @@ struct machine {
 	struct list_head  dead_threads;
 	struct thread	  *last_match;
 	struct vdso_info  *vdso_info;
+	struct perf_env   *env;
 	struct dsos	  dsos;
 	struct map_groups kmaps;
 	struct map	  *vmlinux_maps[MAP__NR_TYPES];

tools/perf/util/session.c

@@ -138,6 +138,8 @@ struct perf_session *perf_session__new(struct perf_data_file *file,
 			perf_session__set_id_hdr_size(session);
 			perf_session__set_comm_exec(session);
 		}
+	} else  {
+		session->machines.host.env = &perf_env;
 	}
 
 	if (!file || perf_data_file__is_write(file)) {